Peritoneal membrane injury induces the activation of local fibroblasts and tissue remodelling, which ultimately can progress to fibrosis. Metastasis of colorectal cancer (CRC) to the abdominal cavity results in such peritoneal damage. Patients with colorectal cancer peritoneal metastasis (CPM) have a particularly poor prognosis, and CPM tumours are characterised by a high infiltration of fibroblasts. Here, we characterised the molecular and functional features of these fibroblasts, and investigated their interaction with other cells in the peritoneal microenvironment. Primary fibroblasts were isolated from 89 patients with different malignant and benign disorders of the peritoneum. We performed comprehensive analyses of single-cell and transcriptome profiling, secretome characterization, and functional enzymatic activity. We were able to identify a peritoneum-specific fibroblast population that increases in response to different types of damage-inducing peritoneal pathologies, including metastasis. These fibroblasts are characterised by the IGFBP2-dependent expression of CD38, which mediates extracellular non-canonical adenosinergic activity and contributes to the suppression of macrophages and T cells. Importantly, peritoneal fibroblasts promoted the growth and invasiveness of tumour cells in a xenograft mouse model of peritoneal metastasis, highlighting their pro-tumorigenic role. Their specific gene signature was associated with poor prognosis in a dataset of 51 patients suffering from colorectal peritoneal metastasis. This study revealed that the CPM is infiltrated by a peritoneal fibroblast subtype, which is absent in healthy tissue, but also observed in benign peritoneal diseases. Given the limited therapeutic options for these patients, these pro-tumorigenic peritoneal fibroblasts could represent an attractive target for inhibiting the peritoneal spread of tumour cells.

Repeat cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) (rCRS-HIPEC) has improved the long-term survival of select patients with acceptable perioperative morbidity and mortality. The pattern of peritoneal disease recurrence is critical in determining eligibility for rCRS-HIPEC. This study evaluated the accuracy, sensitivity and specificity of the radiological peritoneal cancer index (PCI) across different imaging modalities in rCRS-HIPEC patients.

This was a retrospective study on patients with peritoneal disease recurrence who underwent rCRS-HIPEC between January 2022 to December 2023. The accuracy, sensitivity, and specificity of the radiological PCI in predicting the surgical PCI was calculated overall and for each imaging modality at each abdominal region.

32 patients were included in this study. The accuracy, sensitivity and specificity of the overall radiological PCI was 63.0%, 30.8% and 79.9%, respectively. Accuracy (67.5 vs. 62.6%) and specificity (84.8% vs. 75.8%) were higher in FDG-PET versus CT. The sensitivities of all imaging modalities were low (CT 34.9%, FDG-PET 33.3%). FDG-PET and CT had high sensitivities in detecting pelvic disease (80% and 87.5%) but low sensitivities in identifying small bowel (25-33.3% for both modalities) and epigastric disease (25% and 0%). For each abdominal region, the difference between radiological and surgical PCI did not differ significantly based on imaging modality.

Overall, the radiological PCI has a good specificity in rCRS-HIPEC patients and should be used to guide perioperative decision-making. FDG-PET had superior accuracy and specificity in comparison to CT in detecting peritoneal disease recurrence.

Accurate diagnosis is essential for effective cancer treatment, particularly in peritoneal surface malignancies, where failure to detect metastatic lesions can mislead the treatment plan. This study assessed the diagnostic accuracy of staging laparoscopy using the integration of artificial intelligence (AI)-guided photodynamic diagnosis (PDD) with the photosensitizer Phonozen, activated at 405 nm in a rabbit model. To create peritoneal carcinomatosis, VX2 cells were inoculated laparoscopically into the peritoneum of female white New Zealand rabbits. Conventional and PDD-guided laparoscopy utilized a customized light source that emitted broad-spectrum white light or 405-nm blue light, respectively. The surgical procedure comprised a tripartite approach: exploration and labeling of suspected nodules under white-light visualization, identification of additional metastatic tumors under blue-excitation fluorescent light, and confirmatory open laparotomy to locate overlooked nodules by palpation. Our results showed that the initial experimental data from 371 nodules in 14 rabbits, comparing conventional diagnostic laparoscopy and PDD, showed increased detection sensitivity from 67% ± 1.9% (conventional) to 98% ± 0.7% (PDD) in the small-size nodule. In the second experimental data set from 265 nodules in 10 rabbits, the addition of a real-time AI algorithm further increased the sensitivity to 100% ± 0.0%. Combining PDD with AI enhances the detection of peritoneal cancer metastasis in staging laparoscopy.

Appendiceal neoplasms and colorectal cancer have a propensity to develop peritoneal metastases. Despite advancements in systemic therapy and surgical management, the development and management of peritoneal metastases remains a challenging problem. Utilization of adjuvant or prophylactic hyperthermic intraperitoneal chemotherapy has been described, with varying quality of data and reported outcomes. The utilization of prophylactic or adjuvant hyperthermic intraperitoneal chemotherapy in patients with appendiceal neoplasms and colorectal cancer remains an active area of exploration.

Background: T4 colorectal cancer (CRC) is associated with an increased risk of peritoneal metastases (PM), but it is currently not possible to accurately predict which patients with T4 CRC develop PM. We investigated the occurrence and risk factors for PM in these patients. Methods: A mono-institutional prospective database of 352 patients undergoing T4 primary CRC resection from 2012 to 2021 was reviewed. Clinico-pathological variables potentially associated with synchronous or metachronous PM were tested by univariate and multivariate analyses. Results: The prevalence of synchronous PM was 73/352 (20.7%) and was significantly associated with age (p = 0.037), primary site (p = 0.002), positive nodes (p = 0.005), elevated CA19.9 (p = 0.001), and non-intestinal histology (p = 0.001). After a median follow-up of 35.9 months (95% confidence interval [CI] = 29.5-44.9), metachronous CRC-PM occurred in 36/164 patients (22.0%) with available data, accounting for a three-year cumulative incidence of 21.5% (95% CI = 14.3-28.1). Metachronous CRC-PM occurred in 3/48 patients (6.2%) with negative nodes and normal CEA, as compared with 33/116 patients (28.4%) with positive nodes and/or elevated CEA (p < 0.001). Combined nodal and CEA status (hazard ratio [HR] = 1.27; 95% CI = 1.02-1.59; p = 0.033), postoperative chemotherapy (HR= 0.51; 95% CI = 0.33-0.77; p = 0.001), and positive resection margins (HR = 2.01; 95% CI = 1.20-3.39; p = 0.008) were significantly associated with PM. Conclusions: The peritoneum is a major site for treatment failure in T4 CRC. Patients with normal CEA and negative lymph nodes are associated with a significantly lower risk for metachronous CRC-PM. These findings may help in refining patient selection for integrated approaches aiming at the prevention or early treatment of CRC-PM, which are pending validation in prospective studies.

Consensus regarding the hyperthermic intraperitoneal chemotherapy (HIPEC) for colorectal cancer (CRC) regimen remains elusive. In this study, patient-derived tumor organoids from CRC were utilized as a preclinical model for in vitro drug testing of HIPEC regimens commonly used in clinical practice. This approach was used to facilitate the clinical formulation of HIPEC.

Tumor tissues and corresponding clinical data were obtained from patients diagnosed with CRC at the Sixth Affiliated Hospital of Sun Yat-Sen University. Qualified samples were cultured and passaged. We aimed to assess the sensitivity of in vitro hyperthermic perfusion using five different regimens, i.e. mitomycin C, mitomycin C combined with cisplatin, mitomycin C combined with 5-fluorouracil, oxaliplatin, and oxaliplatin combined with 5-fluorouracil.

Tumor organoids obtained from 46 patients with CRC were cultured, and in vitro hyperthermic perfusion experiments were conducted on 42 organoids using five different regimens. The average inhibition rate of mitomycin C was 85.2% (95% confidence interval [CI] 80.4-89.9%), mitomycin C combined with cisplatin was 85.5% (95% CI 80.2-90.7%), mitomycin C combined with 5-fluorouracil was 65.6% (95% CI 59.6-71.6%), oxaliplatin was 37.9% (95% CI 31.5-44.3%), and oxaliplatin combined with 5-fluorouracil was 40.7% (95% CI 33.9-47.5%).

In vitro hyperthermic perfusion demonstrates that the inhibition rate of mitomycin C, both alone and in combination with cisplatin, surpasses that of the combination of mitomycin C with 5-fluorouracil and oxaliplatin. In clinical practice, the combination of mitomycin C and cisplatin can be regarded as the optimal choice for HIPEC in CRC.

Peritoneal metastasis (PM) is common in colorectal cancer (CRC), yet its underlying mechanisms are poorly understood. Here, we explored the transcriptional profile of CRC, PM and adjacent tissues revealing key players that facilitate PM. Single-cell analysis of 48 matched samples from 12 patients revealed that remodeling of malignant cells and the tumor microenvironment promotes CRC progression and metastasis. Multiplexed imaging confirmed depletion in PM by enrichment in CRC tissues of neutrophils associated with mucosal immunity disruption, intestinal microbiota dysbiosis and mesenchymal transition of both cancerous and mesothelial cells. Functional analyses in cell lines, organoids and in vivo models demonstrated that dysbiosis promoted inflammation and protumor neutrophil recruitment, while coupled mesenchymal transition of malignant and mesothelial cells disrupted the stromal structure and increased cancer cell invasiveness. Our findings suggest that targeting mesothelial cells and tumor microenvironment remodeling may offer therapeutic strategies for CRC-PM.

Appendiceal adenocarcinoma represents a diagnostic and therapeutic challenge since it is prone to early lymphatic and peritoneal spread. We aimed to analyze the proportion of lymph node metastases in completion right hemicolectomy specimens, risk factors for peritoneal metastases (PM), and prognosis after definitive treatment.

Ninety-three patients with appendiceal adenocarcinoma scheduled for cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS + HIPEC) in Uppsala 2004-2020 were identified from a prospectively maintained registry. Risk factors for PM were assessed based on the presence (CT + group, n = 55) or absence (CT - group, n = 37) of visible PM at baseline CT scan. Prognostic factors were analyzed based on the actual presence (PM group, n = 66) or absence (no PM group, n = 27) of PM.

The median age was 60 (26-78). Forty-eight patients were women. Resection of PM at initial surgery indicated an 80 % risk of finding PM at a follow-up exploration. R1 appendectomy and perforated appendix had a similar risk for PM (24 %,26 %) which increased to 38 % if both were present. Regional lymph node metastases occurred in 31 % in the CT + group vs. 14 % in the CT - group (p = 0.005) and was associated with poor survival HR 5.16 (1.49-17.81). The 5-year OS and DFS rates were 54 % and 29 % in the PM group.

Patients with certain risk factors have a high likelihood of PM despite a normal CT scan, which justifies selective exploration at a HIPEC center. Regional lymph node spread supports the current practice of completion right hemicolectomy and is a significant prognostic factor.

Peritoneal malignancies encompass a diverse range of tumors originating within the peritoneum, including primary tumors such as mesothelioma and primary serous peritoneal carcinoma or secondary tumors resulting from the spread of cancers from gastrointestinal, gynecological, and extra-abdominal sources. The traditional approach of palliative care for these malignancies is being replaced by a multimodal strategies that integrates surgery with systemic or intraperitoneal chemotherapy. Notably, cytoreductive surgery combined with hyperthermic intraperitoneal chemotherapy has shown significant improvements in survival rates. Imaging is crucial in the multidisciplinary management of these tumors, aiding in diagnosis, staging, restaging, and monitoring therapy response. It is also vital for appropriate patient selection, using the acronym "PAUSE", which involves assessing tumor burden via the peritoneal carcinomatosis index, evaluating patients pre- and post-therapy, detecting complications following therapy, and predicting treatment outcomes. This review explores the imaging manifestations of peritoneal malignancies, distinguishing them from various mimics, and underscores the importance of imaging modalities such as CT, MRI, PET/CT, and PET/MRI in effective decision-making and management.

Cytoreductive surgery has shown survival benefits for colorectal cancer (CRC) patients with peritoneal metastasis. However, the optimal extent of peritonectomy remains controversial in cases of limited peritoneal metastases. This study modified selective pelvic peritonectomy (SPP) into subtotal pelvic peritonectomy (STPP) for metastasis confined to pelvic cavity, and aimed to evaluate its feasibility, safety, and impact on survival outcomes.

CRC patients with limited peritoneal metastasis confined to the pelvic cavity who underwent CC0 (no macroscopic residual cancer remained) resection were included from a prospectively collected database. Surgical complications, disease-free survival (DFS), and overall survival (OS) were analyzed.

A total of 67 patients were included (26 in the STPP group and 41 in the SPP group). Clinically, STPP was found to be feasible and without increased surgical complications or mortality rates. At a median follow-up of 33.9 months, the 3-year DFS was 65.9 % and 30.7 % in STPP and SPP groups, respectively (P= 0.002). The 3-year OS was 84.1 % and 68.5 % in STPP and SPP groups, respectively (P= 0.006). Moreover, STTP was independently associated with improved DFS (HR = 0.351, 95 % CI 0.165-0.745, P= 0.006) and OS (HR = 0.324, 95 % CI 0.116-0.902, P=0.032). Female gender was also independently associated with poor DFS (HR = 2.146, 95 % CI 1.078-4.271, P= 0.031). Among 24 female patients with remaining ovaries, 9 (37.5 %) cases developed metachronous ovarian metastasis, and of these 6 underwent a second operation.

Subtotal pelvic peritonectomy is associated with promising long-term outcomes in CRC patients with peritoneal metastasis confined to the pelvic cavity. Prophylactic bilateral oophorectomy should be strongly considered during cytoreductive surgery.

disease burden (PCI), completeness of cytoreduction or histological features, are known to influence survival after CRS-HIPEC for colorectal peritoneal metastases (CPM). However, there is still debate about influence of CPM onset. The aim of this study is to determine the impact of CPM onset on oncological outcomes after CRS-HIPEC.

all patients with CPM scheduled for CRS-HIPEC at one reference center between December 2007 and September 2022 were included. s-PM were defined as those diagnosed at primary disease treatment; m-PM were considered those diagnosed during follow-up. Survival outcomes and recurrence rates were compared using a pragmatic analysis.

125 patients with s-CPM and 170 patients with m-CPM were analyzed. Median follow-up was 58.6 and 50.6 months in s-CPM and m-CPM groups(p = 0.11). Complete cytoreduction (CCS-0/-1) rates were comparable: 84 % s-CPM vs. 88.2 % m-CPM(p = 0.190). Overall survival (OS) was significantly shorter in s-CPM: 24.7 vs. 46.6 months (p = 0.024). Conversely, median disease-free survival was similar in both groups, 10 months vs. 11 months(p = 0.155). Patients in the s-CPM group presented more pN+(p = 0.001), higher histologic grade(p = 0.007) and PCI(p = 0.04), and higher rate of concurrent liver metastases(p = 0.004). RAS/BRAF gene mutations and microsatellite instability did not differ significantly. Perioperative chemotherapy regimens and tolerance were also similar.

despite s-CPM being associated with impaired OS after CRS-HIPEC, the onset of PM was not found to be an independent determinant for survival. High-risk molecular and histological features strongly influence oncological outcomes after CRS-HIPEC. This is valuable data that could aid in preoperative patient selection process for CRS-HIPEC.

Data in the literature suggest that obstruction is an independent predictor of poor prognosis in colon cancer. Of all possible sites of recurrence, peritoneal metastases are associated with worse survival. Our aim was to report the incidence of metachronous peritoneal metastases from a cohort of patients undergoing resection of obstructive colon cancer with curative intent and to identify predictive factors for metachronous peritoneal metastases.

From 2000 to 2015, a total of 2,325 patients were treated for obstructive colon cancer in French surgical centers, members of the French National Surgical Association (AFC). Patients with palliative management, synchronous metastatic disease, and with postoperative mortality were excluded. A multivariate analysis was performed to determine independent predictive factors of metachronous peritoneal metastases.

The cohort included 1,085 patients. The median follow-up was 21.5 months. Metachronous peritoneal metastases occurred in 12% of patients and were diagnosed after a median interval of 13.5 months. The cumulative 3-year metachronous peritoneal metastasis rate was 10.9%. Three-year overall survival was 85% for patients who did not develop recurrence, 71% for those who develop recurrence without peritoneal metastases, and 56% for those with metachronous peritoneal metastases (P < .0001). In multivariate analysis, 3 variables were identified as independent risk factors for metachronous peritoneal metastases: pT4 stage (odds ratio: 1.98; 95% confidence interval: 1.17-3.36; P = .011), pN2 stage (odds ratio: 2.57; 95% confidence interval: 1.89-4.45; P = .0007), and fewer than 12 lymph nodes examined (odds ratio: 2.01; 95% confidence interval: 1.08-3.74; P = .028).

This study showed a significant risk of metachronous peritoneal metastases after curative-intent resection of obstructive colon cancer. The awareness of factors predisposing to metachronous peritoneal metastases could improve the treatment strategy of these patients.

Although curative resection for synchronous peritoneal carcinomatosis has been reported to improve prognosis, cases with positive intraoperative lavage cytology have not been reported. In this study, we investigated the prognostic value of potentially curative resection based on colorectal cancer and lavage cytology positivity in patients with synchronous peritoneal carcinomatosis.

We retrospectively evaluated 72 patients who underwent intraoperative lavage cytology and one-stage potentially curative resection of primary and metastatic lesions (lavage cytology-positive, n = 21; lavage cytology-negative, n = 51) between July 2004 and December 2019. We compared the 5-year overall survival and 3-year recurrence rates between the lavage cytology-positive and lavage cytology-negative groups.

No significant differences were observed in the 5-year overall survival (48.2% vs. 45.5%, P = 0.924) or 3-year recurrence rates (74.5% vs. 62%, P = 0.143) between the two groups. Univariate analysis for 3-year recurrence revealed that lavage cytology-positive status was not an explanatory variable (hazard ratio: 1.552, 95% confidence interval: 0.83-2.902, P = 0.169). Multivariate analysis identified colon cancer as an independent risk factor of recurrence.

In resectable cases, the resection of synchronous peritoneal carcinomatosis from colorectal cancer can be considered even if intraoperative lavage cytology is positive.

Colorectal cancer (CRC) continues to be a significant global health issue contributing to a high mortality rate. Despite advancements in treatment, the risk of recurrence remains due to inherent mutations and the rapid turnover of intestinal mucosa. We present an exceptionally rare case of CRC metastasis to the duodenum in a 42-year-old female who has been compliant with postsurgical surveillance. Despite previous negative surveillance results, elevated CEA levels and a 3-cm mesenteric mass were detected, raising concerns for carcinoma, which was later confirmed by biopsy. The tumor board deemed her ineligible for surgery due to vascular involvement, leading to palliative care and an attempt at neoadjuvant therapy. Vigilant monitoring is crucial for early detection and intervention.

Cytoreductive surgery provides a chance for long-term survival and cure in selected patients with colorectal peritoneal metastases. As clinical and academic interest in this field increases, heterogeneity in outcome reporting hinders the valid and meaningful synthesis of data into high-quality meta-analyses. The aim of this systemic review was to investigate variability in outcome reporting following cytoreductive surgery with or without intraperitoneal chemotherapy for colorectal peritoneal metastases.

Five electronic databases [MEDLINE, Embase, Scopus, Cochrane Central Register of Controlled Trials (CENTRAL) and Cumulative Index to Nursing and Allied Health Literature (CINAHL)] were interrogated from 2000 to October 2023 to identify all reported outcomes in the current literature. Extracted outcomes were catalogued and reviewed by a multidisciplinary working group into standardized terms and domains.

A total of 294 studies, from 5112 screened, were included for analysis. We extracted 2903 outcomes verbatim from included studies and catalogued them into 85 standardized outcomes across seven outcome domains. The most frequently reported domains were survival, in 274 (93%) studies, and pathological outcomes, in 232 (79%) studies. Outcomes pertaining to function and life impact were only reported in seven (2%) studies. Reported outcomes were only defined in 35% of cases, and significant variability existed between definitions.

This systematic review highlights the heterogeneity of outcome measurement and reporting following cytoreductive surgery for colorectal peritoneal metastases. Patient-reported outcomes are relatively underrepresented in the current literature. The results of this review will inform an international collaborative effort to create a core outcome set to address these issues.

Peritoneal metastasis (PM) is the life-threatening cause of colorectal cancer patients (CRC). Adjuvant hyperthermic intraperitoneal chemotherapy (HIPEC) plus cytoreductive surgery exhibited promising effects in preventing recurrence and increasing the survival of CRC patients. However, the outcomes of HIPEC on treating advanced CRC with risk of PM are still controversial. Here, we retrospectively examined the impact of HIPEC on preventing PM and its overall effects on patients with locally advanced CRC who underwent primary curative resection at our center.

We retrospectively analyzed 45 patients diagnosed with locally advanced colorectal cancer (CRC) who underwent primary curative laparoscopic surgery with proactive hyperthermic intraperitoneal chemotherapy (HIPEC), in conjunction with adjuvant systemic chemotherapy at our center between 2019 and 2022. An additional 55 patients with locally advanced CRC who underwent similar surgery and received adjuvant systemic chemotherapy but did not undergo HIPEC during the same period were selected as the control group. Disease-free survival (DFS), overall survival (OS), and PM incidence were compared between patients with and without HIPEC.

The cumulative PM incidence was 2.2% in the HIPEC group and 14.5% in the control group(P = 0.0347). No significant adverse effects were observed in the HIPEC group. Furthermore, Kaplan-Meier survival analysis showed that the HIPEC correlated to better DFS [hazard ratio (HR) 0.4670, 95% confidence interval (CI) 0.2305-0.9462; P = 0.0345] and extended the overall survival of CRC patients [hazard ratio (HR) 0.3978, 95% confidence interval (CI) 0.1684-0.9395; P = 0.0355]. Therefore, our data supports that adjuvant HIPEC can prevent peritoneal failure in CRC patients and improve both PFS and OS survival following primary curative resection.

DW-MRI is a non-invasive way to determine the peritoneal cancer index (PCI) in colorectal cancer (CRC) patients with peritoneal metastases (PM). However, like surgeons during surgery, radiologists struggle to differentiate between PM and fibrosis. This study aimed to investigate the agreement between the PCI as determined by MRI (mriPCI), during surgery (sPCI) and histopathology examination (pPCI) in CRC patients undergoing cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS-HIPEC).

This was a single-centre, retrospective study of CRC patients with PM who were staged with DW-MRI and underwent subsequent CRS-HIPEC. All initial patients' radiological, surgical and histopathology reports were reviewed for the PCI. Histopathology was the reference standard. Primary outcome was the correlation and agreement between mriPCI and pPCI.

Eighty-seven patients were included. All patients had a complete macroscopic resection. Median (interquartile range) PCI for MRI, surgery, and histopathology were respectively 6.0 (2.5-9.0), 6.0 (4.0-11.0) and 6.0 (2.5-9.5). The intraclass correlation coefficient between the sPCI and pPCI was excellent 0.87 (p <0.001), and good between mriPCI and pPCI 0.77 (p <0.001) and between sPCI and mriPCI 0.70 (p <0.001).

MRI is a promising non-invasive tool to assess the PCI rather accurately.

The peritoneal metastasized colorectal cancer (pmCRC) represents a serious health problem worldwide with a special emphasis in the developed countries. Several guidelines recognize the role of multimodal therapy consisting of cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) in the treatment of pmCRC. New data suggests that some other factors, eg, tumor biology, immune profile, neoadjuvant chemotherapy may play a predictive role for the oncological outcome of these patients.

In the United States, often only tertiary centers offer cytoreductive surgery and heated intraperitoneal chemotherapy (CRS+HIPEC) for peritoneal metastases in advanced lower gastrointestinal malignancies. Growing evidence shows that Medicaid expansion under the Affordable Care Act (ACA) of 2010 enhanced healthcare access and outcomes.

We sought to determine whether Medicaid expansion was associated with decreased all-cause mortality of lower gastrointestinal cancer patients following CRS+HIPEC.

We analyzed data from the National Cancer Database (2010-2019) on lower gastrointestinal cancer patients who underwent CRS+HIPEC. Medicaid expansion, introduced under the ACA in 2010, extends health insurance to low-income adults. We categorized states by expansion timing: early (2010-2013), immediate (January 2014), late (after January 2014), or no expansion to assess the impact of Medicaid expansion on mortality using a multivariable Cox regression model.

Of the 1001 study patients, 671 (67%) were diagnosed in Medicaid expansion states. Grade and Medicaid expansion status were the only factors independently associated with overall survival on multivariable analysis. On average, patients in Medicaid expansion states experienced a 4% increase in annual survival compared with those in non-expansion states who had a 1% decrease in annual survival over the study period.

Patients from states that had an early expansion of Medicaid and patients with lower-grade tumors had significantly better overall survival. Our study findings suggest that improved access to healthcare through Medicaid expansion was associated with increased survival rates of lower gastrointestinal cancer patients who undergo CRS+HIPEC for the treatment of peritoneal metastases.

This study aimed to investigate the risk factors for peritoneal recurrence (PR) in patients with stage II to III colorectal cancer who underwent colorectal surgery.

A retrospective study was conducted on 232 patients who underwent colorectal surgery for stage II to III colorectal cancer. Univariate and multivariate analyses were performed to determine risk factors for PR.

The overall incidence of PR was 8.2 % (19/232). A univariate Cox regression analysis showed that a higher level of carcinoembryonic antigen (CEA) (P = 0.039), higher levels of carbohydrate antigen 19-9 (CA19-9) (P < 0.001), preoperative bowel obstruction (P = 0.011), tumor invasion of T4 category (P = 0.019), lymph node metastasis (P = 0.016), poorly differentiated, mucinous or signet-ring histological type (P = 0.010), larger amount of intraoperative bleeding (P = 0.002), R1 resection (P = 0.003), anastomotic leakage Clavien-Dindo classification (CD) ≥2 (P = 0.018), longer postoperative stay (P = 0.002), and recurrence of other organs preceding disseminated recurrence (P = 0.004) were observed significantly more frequently in patients with PR than in patients without PR. A multivariate Cox regression analysis revealed that poorly differentiated, mucinous, or signet-ring histological type (HR: 5.067, 95 % CI: 1.192-21.534, P = 0.028) and intraoperative bleeding (HR: 1.003, 95 % CI: 1.000-1.005, P = 0.017) were independent risk factors for PR. Peritoneal recurrence-free survival curves generated using the Kaplan-Meier method gradually worsened with increasing intraoperative bleeding (P < 0.001). In addition, the sub-analyses between stage II and stage III and between ≤ cT3 and cT4 also demonstrated that peritoneal recurrence-free survival worsened with increasing intraoperative bleeding.

Our findings suggest that histological type, and intraoperative bleeding are risk factors for PR in patients who undergo colorectal surgery for stage II to III colorectal cancer. In particular, peritoneal recurrence is associated with increased intraoperative bleeding.

Ascites is common in advanced gastrointestinal cancers with peritoneal metastases (PM) and negatively impacts patient survival. No study to date has specifically evaluated the relationship between ascites, PM and survival outcomes in metastatic colorectal cancer (mCRC) and metastatic gastric cancer (mGC).

This study aims to investigate and elucidate the relationship between malignant ascites, PM and survival outcomes in both mCRC and mGC patients.

This is a retrospective analysis of prospectively collected clinical trial data of mCRC and mGC patients with PM.

We performed two pooled analyses, firstly of two Italian randomized trials enrolling patients with mCRC eligible for systemic therapy (TRIBE2; VALENTINO), and secondly of gastric cancer and peritoneal metastasis (GCPM) patients who underwent bi-directional therapeutic treatment comprising systemic and peritoneal-directed therapies.

Of 900 mCRC patients, 39 (4.3%) had PM with malignant ascites. Compared to the group without PM, median progression-free and overall survival were significantly inferior in the ascites group (hazard ratio (HR) for progression-free survival (PFS) 1.68, 95% confidence interval (CI): 1.21-2.35, p = 0.007; HR for overall survival (OS) 2.14, 95% CI: 1.57-3.01, p < 0.001), but not in the group of PM without ascites (HR for PFS 1.10, 95% CI: 0.91 - 1.34; HR for OS 1.04, 95% CI: 0.84 - 1.30). Of 170 patients with GCPM, those with ascites had higher median Peritoneal Cancer Index scores (23 vs 9, p < 0.001). Median OS was significantly inferior among those with ascites compared to those without (13.0 vs 21.0 months, HR 1.71, 95% CI: 1.16-2.52, p = 0.007).

Ascites identifies a subgroup of patients with PM and poor outcomes, for whom tailored research are needed.

Colorectal cancer (CRC) is associated with high incidence and mortality rates globally. The presence of intraperitoneal free cancer cells (IFCCs) is recognized as an independent prognostic factor for CRC patients. However, a clinical gold standard for IFCCs detection is lacking. The GILUPI CellCollector has demonstrated high sensitivity and specificity in detecting free cancer cells, yet its application for CRC IFCCs detection remains unreported.

We selected CRC and normal cell lines to evaluate the CellCollector's ability to detect tumor cells. A total of 70 CRC patients and 17 patients with benign disease undergoing laparoscopic procedures were investigated. Peritoneal lavage fluid was collected pre- and post-operation, and both real-time PCR (CEA mRNA) and CellCollector detection were performed. We compared the sensitivity and specificity of these two methods.

CellCollector can distinguish well between CRC and normal cells in cell line experiments. CellCollector detects IFCCs better than real-time PCR (CEA) in CRC patients in different TNM Stages. The sensitivity of CellCollector was higher than that of real-time PCR (84.6% vs. 48.4%), and the specificity of CellCollector was also higher than real-time PCR (79.1% vs. 60.4%). There was no significant difference in the results of IFCCs detected by CellCollector before and after total mesorectal excision (TME) or complete mesocolic excision (CME) radical colorectomy (p > 0.05), but there was a significant difference in real-time PCR detection (p < 0.05).

The CellCollector demonstrates superior sensitivity and specificity compared to real-time PCR for detecting IFCCs in CRC patients, suggesting its potential as a clinical tool for IFCCs detection.

ClinicalTrials.gov identifier: NCT01978444.

Peritoneal metastasis from colorectal cancer carries a high risk for relapse after cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS-HIPEC). A novel alpha-emitting radiopharmaceutical (Radspherin) has been designed to deliver short-range radiation to micrometastases and free-floating tumor cells.

A Phase 1/2a study evaluated the safety, tolerability, and signal of efficacy of escalating doses of Radspherin injected intraperitoneally after CRS-HIPEC.

Eleven patients received 1-4 MBq (Group 1) whereas 12 patients received 7 MBq; nine patients single dose/three patients split-dose (Group 2). Median age was 66.5 and 61.5 years, and median peritoneal cancer index 6 and 7, respectively. One hundred and seventy-eight adverse events were reported, only seven were deemed related to Radspherin. Thirteen serious adverse events (SAEs) were reported in eight patients and no SAEs were related to Radspherin. At 18-months, none of the 12 patients receiving 7 MBq experienced peritoneal recurrences, however four had non-peritoneal recurrences. Across both groups (n = 22), 41% had recurrent disease, only 14% of them in the peritoneum.

Radspherin was well tolerated. At 18 months, median disease-free survival has not been reached, and none of the patients receiving the recommended dose (7 MBq) had peritoneal recurrences. The results are encouraging and warrant further clinical evaluation.

Pressurized intraperitoneal aerosol chemotherapy (PIPAC) consists of the administration of aerosolized chemotherapy into the abdominal cavity of patients suffering from peritoneal carcinomatosis. Our aim was to review the evidence supporting PIPAC in patients with peritoneal carcinomatosis from colorectal cancer.

A systematic review was performed in accordance with the 2020 PRISMA guideline. MEDLINE and CENTRAL were searched using combinations of terms including "Peritoneal carcinomatosis", "Peritoneal metastasis", "PIPAC", "Pressurized intraperitoneal aerosol chemotherapy" and "Colorectal cancer". Original studies, in English, including patients treated with PIPAC for colorectal peritoneal carcinomatosis, were considered eligible. Case reports, non-English or French language articles and secondary analyses were excluded.

A total of 385 articles were screened and 374 articles were excluded, leaving 11 publications for inclusion in the qualitative analysis. The included studies totalized 949 patients who received PIPAC for peritoneal carcinomatosis due to colorectal cancer. The median peritoneal carcinomatosis index (PCI) ranged from 10 to 31. In all studies, the complete PIPAC protocol was achieved with an average of two to three 3 PIPAC sessions per patient. Oxaliplatin (OX) was used as a chemotherapeutic agent in all studies and could be associated with intravenous 5-FU and leucovorin. Most post-operative adverse events were recorded as mild to moderate with no intraoperative complications. Only four studies reported a decrease in the average PCI score for 50% of the patients. Median overall survival ranged from 8 to 37.8 months. Quality of life indicators were stable between PIPAC-OX cycles with a small but not statistically significant trend of improvement of most functional scales.

PIPAC for peritoneal carcinomatosis from colorectal origin is feasible, safe and tolerable. Its impact on survival outcomes or quality of life remains to be demonstrated by randomized trials.

We compared the relative benefits, harms and cost-effectiveness of hyperthermic intraoperative peritoneal chemotherapy + cytoreductive surgery ± systemic chemotherapy versus cytoreductive surgery ± systemic chemotherapy or systemic chemotherapy alone in people with peritoneal metastases from colorectal, gastric or ovarian cancers by a systematic review, meta-analysis and model-based cost-utility analysis.

We searched MEDLINE, EMBASE, Cochrane Library and the Science Citation Index, ClinicalTrials.gov and WHO ICTRP trial registers until 14 April 2022. We included only randomised controlled trials addressing the research objectives. We used the Cochrane risk of bias tool version 2 to assess the risk of bias in randomised controlled trials. We used the random-effects model for data synthesis when applicable. For the cost-effectiveness analysis, we performed a model-based cost-utility analysis using methods recommended by The National Institute for Health and Care Excellence.

The systematic review included a total of eight randomised controlled trials (seven randomised controlled trials, 955 participants included in the quantitative analysis). All comparisons other than those for stage III or greater epithelial ovarian cancer contained only one trial, indicating the paucity of randomised controlled trials that provided data. For colorectal cancer, hyperthermic intraoperative peritoneal chemotherapy + cytoreductive surgery + systemic chemotherapy probably results in little to no difference in all-cause mortality (60.6% vs. 60.6%; hazard ratio 1.00, 95% confidence interval 0.63 to 1.58) and may increase the serious adverse event proportions compared to cytoreductive surgery ± systemic chemotherapy (25.6% vs. 15.2%; risk ratio 1.69, 95% confidence interval 1.03 to 2.77). Hyperthermic intraoperative peritoneal chemotherapy + cytoreductive surgery + systemic chemotherapy probably decreases all-cause mortality compared to fluorouracil-based systemic chemotherapy alone (40.8% vs. 60.8%; hazard ratio 0.55, 95% confidence interval 0.32 to 0.95). For gastric cancer, there is high uncertainty about the effects of hyperthermic intraoperative peritoneal chemotherapy + cytoreductive surgery + systemic chemotherapy versus cytoreductive surgery + systemic chemotherapy or systemic chemotherapy alone on all-cause mortality. For stage III or greater epithelial ovarian cancer undergoing interval cytoreductive surgery, hyperthermic intraoperative peritoneal chemotherapy + cytoreductive surgery + systemic chemotherapy probably decreases all-cause mortality compared to cytoreductive surgery + systemic chemotherapy (46.3% vs. 57.4%; hazard ratio 0.73, 95% confidence interval 0.57 to 0.93). Hyperthermic intraoperative peritoneal chemotherapy + cytoreductive surgery + systemic chemotherapy may not be cost-effective versus cytoreductive surgery + systemic chemotherapy for colorectal cancer but may be cost-effective for the remaining comparisons.

We were unable to obtain individual participant data as planned. The limited number of randomised controlled trials for each comparison and the paucity of data on health-related quality of life mean that the recommendations may change as new evidence (from trials with a low risk of bias) emerges.

In people with peritoneal metastases from colorectal cancer with limited peritoneal metastases and who are likely to withstand major surgery, hyperthermic intraoperative peritoneal chemotherapy + cytoreductive surgery + systemic chemotherapy should not be used in routine clinical practice (strong recommendation). There is considerable uncertainty as to whether hyperthermic intraoperative peritoneal chemotherapy + cytoreductive surgery + systemic chemotherapy or cytoreductive surgery + systemic chemotherapy should be offered to patients with gastric cancer and peritoneal metastases (no recommendation). Hyperthermic intraoperative peritoneal chemotherapy + cytoreductive surgery + systemic chemotherapy should be offered routinely to women with stage III or greater epithelial ovarian cancer and metastases confined to the abdomen requiring and likely to withstand interval cytoreductive surgery after chemotherapy (strong recommendation).

More randomised controlled trials are necessary.

This study is registered as PROSPERO CRD42019130504.

This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: 17/135/02) and is published in full in Health Technology Assessment; Vol. 28, No. 51. See the NIHR Funding and Awards website for further award information.

Colorectal cancer peritoneal carcinomatosis (CRC PC) necessitates preoperative assessment of inflammatory markers to predict postoperative outcomes and guide treatment. This study aims to evaluate the prognostic value of preoperative Neutrophil-Lymphocyte Ratio (NLR), Platelet-Lymphocyte Ratio (PLR), and Mean Platelet Volume (MPV) in predicting complications for CRC PC patients undergoing surgery.

Calculating NLR, PLR, and MPV from patient data: NLR = absolute neutrophil count/total lymphocyte count, PLR = total lymphocyte count/total platelet count × 100, and MPV = platelet crit (PCT)/total platelet count.

The study included 196 CRC PC patients and found significant relationships between these markers and overall survival (OS). Patients with an NLR of 3.77 had a median OS of 22.1 months, compared to 58.3 months for those with lower NLR (HR 2.7, 95% CI 1.1-5.3, p < 0.001).

For CRC PC patients undergoing CRS+HIPEC, preoperative assessment of NLR, PLR, and MPV can serve as independent prognostic markers for OS. Incorporating these markers into preoperative evaluations may improve patient selection and outcome prediction.

Over decades, peritoneal surface malignancies (PSMs) have been associated with limited treatment options and poor prognosis. However, advancements in perioperative systemic chemotherapy, cytoreductive surgery (CRS), and hyperthermic intraperitoneal chemotherapy (HIPEC) have significantly improved clinical outcomes. PSMs predominantly result from the spread of intra-abdominal neoplasia, which then form secondary peritoneal metastases. Colorectal, ovarian, and gastric cancers are the most common contributors. Despite diverse primary origins, the uniqueness of the peritoneum microenvironment shapes the common features of PSMs. Peritoneal metastization involves complex interactions between tumour cells and the peritoneal microenvironment. Fibroblasts play a crucial role, contributing to tumour development, progression, and therapy resistance. Peritoneal metastasis-associated fibroblasts (MAFs) in PSMs exhibit high heterogeneity. Single-cell RNA sequencing technology has revealed that immune-regulatory cancer-associated fibroblasts (iCAFs) seem to be the most prevalent subtype in PSMs. In addition, other major subtypes as myofibroblastic CAFs (myCAFs) and matrix CAFs (mCAFs) were frequently observed across PSMs studies. Peritoneal MAFs are suggested to originate from mesothelial cells, submesothelial fibroblasts, pericytes, endothelial cells, and omental-resident cells. This plasticity and heterogeneity of CAFs contribute to the complex microenvironment in PSMs, impacting treatment responses. Understanding these interactions is crucial for developing targeted and local therapies to improve PSMs patient outcomes.

Cytoreductive surgery and chemotherapy reportedly improve the prognosis of patients with metachronous peritoneal metastases. However, the types of peritoneal metastases indicated for cytoreductive surgery remains unclear. Therefore, we aimed to clarify the category of cases for which cytoreductive surgery would be effective and report the prognosis associated with cytoreductive surgery for metachronous peritoneal metastases.

This study included 52 consecutive patients who underwent cytoreductive surgery for metachronous peritoneal metastases caused by colorectal cancer between January 2005 and December 2018 and fulfilled the selection criteria. The median follow-up period was 54.9 months. Relapse-free survival was calculated as the time from cytoreductive surgery of metachronous peritoneal metastases to recurrence. Overall survival was defined as the time from cytoreductive surgery of metachronous peritoneal metastases to death or the end of the follow-up period.

The 5-year relapse-free survival rate was 30.0% and the 5-year overall survival rate was 72.3%. None of the patients underwent hyperthermic intraperitoneal chemotherapy. The analysis indicated no potential risk factors for 5-year relapse-free survival. However, for 5-year overall survival, the multivariate analysis revealed that time to diagnosis of metachronous peritoneal metastases of < 2 years after primary surgery (hazard ratio = 4.1, 95% confidence interval = 2.0-8.6, p = 0.0002) and number of metachronous peritoneal metastases ≥ 3 (hazard ratio = 9.8, 95% confidence interval = 2.3-42.3, p = 0.002) as independent factors associated with a poor prognosis.

Long intervals of more than 2 years after primary surgery and 2 or less metachronous peritoneal metastases were good selection criteria for cytoreductive surgery for metachronous peritoneal metastases from colorectal cancer.

Colorectal cancer (CRC) is a prevalent cancer with intraperitoneal free cancer cells (IFCCs) playing a significant role in prognosis, especially during surgeries. The identification of IFCCs is crucial for determining the stage and treatment of patients with CRC. Existing methods for IFCC detection, such as conventional cytology, immunocytochemistry (ICC), and polymerase chain reaction (PCR), have limitations in sensitivity and specificity. This study investigates the potential of long noncoding RNA (lncRNA) SNHG1 as a biomarker for detecting IFCCs in patients with CRC. Testing on a cohort of 91 patients with CRC and 26 patients with gastrointestinal benign disease showed that SNHG1 outperformed CEA in distinguishing CRC cells and detecting IFCCs across different disease stages. SNHG1 demonstrated higher sensitivity (76.1% vs. 43.1%) and specificity (68.4% vs. 52.3%) than CEA for IFCC detection in patients with CRC, suggesting its promising role as a clinical method for identifying IFCCs in CRC.

Colorectal cancer (CRC) is the third most common cancer worldwide. In the United States alone, CRC was responsible for approximately 52,550 deaths in 2023, with an estimated 153,020 new cases. CRC presents with synchronous peritoneal spread in 5-10% of patients, and up to 20-50% of patients with recurrent disease will develop metachronous colorectal cancer peritoneal metastatic (CRC-PM) disease. Eradication of the tumor, tumor margins and microscopic residual disease is paramount, as microscopic residual disease is associated with local recurrences, with 5-year survival rates of less than 35%. The success of resection and reduction of residual disease depends on the accuracy with which cancer cells and normal tissue can be intra-operatively distinguished. Fluorescence Molecular Imaging (IFMI) and tumor-targeted contrast agents represent a promising approach for intraoperative detection and surgical intervention. Proper target selection, the development of scalable imaging agents and enhanced real-time tumor and tumor microenvironment imaging are critical to enabling enhanced surgical resection. LGR5 (leucine-rich repeat-containing G-protein-coupled receptor 5), a colonic crypt stem cell marker and the receptor for the R-spondins (RSPO) in the Wnt signaling pathway, is also expressed on colorectal cancer stem cells (CSC) and on CRC tumors and metastases, suggesting it could be a useful target for imaging of CRC. However, there are numerous diverging reports on the role of LGR5 in CRC therapy and outcomes. Herein, we report on the synthesis and validation of a 37 amino acid RSPO1-mimetic peptide, termed RC18, that was specifically designed to access the R-spondin binding site of LGR5 to potentially be used for interoperative imaging of CRC-PM. The receptor-binding capabilities of the RC18 indicate that direct interactions with LGR5 neither significantly increased LGR5 signaling nor blocked RSPO1 binding and signal transduction, suggesting that the RSPO1-mimetic is functionally inert, making it an attractive contrast agent for intraoperative CRC-PM imaging.

Even with systemic chemotherapy, cytoreductive surgery (CRS), and hyperthermic intraperitoneal chemotherapy (HIPEC), peritoneal metastases (PM) remain a common site of disease progression for colorectal cancer (CRC) and are frequently associated with a poor prognosis. The mass spectrometry (MS) method known as Matrix-Assisted Laser Desorption/Ionization - Time of Flight (MALDI-TOF) is frequently used in medicine to identify structural compounds and biomarkers. It has been demonstrated that lipids are crucial in mediating the aggressive growth of tumors. In order to investigate the lipid profiles, particularly with regard to histological distribution, we used MALDI-TOF MS (MALDI-MS) and MALDI-TOF imaging MS (MALDI-IMS) on patient-derived tumor organoids (PDOs) and PM clinical samples. According to the MALDI-IMS research shown here, the predominant lipid signature of PDOs in PM tissues, glycosphingolipid (GSL) sulfates or sulfatides, or STs, is unique to the areas containing tumor cells and absent from the surrounding stromal compartments. Bioactive lipids are derived from arachidonic acid (AA), and AA-containing phosphatidylinositol (PI), or PI (18:0-20:4), is shown to be highly expressed in the stromal components. On the other hand, the tumor components contained a higher abundance of PI species with shorter and more saturated acyl chains (C34 and C36 carbons). The cellular subversion of PI and ST species may alter in ways that promote the growth, aggressiveness, and metastasis of tumor cells. Together, these findings suggest that the GSL/ST metabolic programming of PM may contain novel therapeutic targets to impede or halt PM progression.

The occurrence of metachronous metastases (MM) of colorectal (CRC), colon (CC), and rectal (RC) cancer of population-based studies has not been compiled in a systematic review previously.

MEDLINE, Embase, and Cochrane Library were searched for primary studies of any design from inception until January 2021 and updated in August 2023 (CRD42021261648). The PRISMA guidelines were adopted, and the Newcastle-Ottawa Quality Assessment Scale used for risk of bias assessment. Outcomes on overall and organ-specific MM were extracted. A narrative analysis followed.

Out of 2143 unique hits, 162 publications were read in full-text and 37 population-based cohort studies published in 1981-2022 were included. Ten studies adopted time-dependent analyses; eight were registry-based and seven had a low risk of bias. Three studies reported 5-year recurrence rate of MM overall of stages I-III; for CRC, it was 20.5%, for CC, it was 18% and 25.6%, and for RC, it was 23%. Four studies reported 5-year recurrence rate of organ-specific MM of stages I-III-for CRC, it was 2.2% and 5.5% for peritoneal metastases and 5.8% for lung metastases and for CC 4.5% for peritoneal metastases. Twenty-seven studies reported proportions of patients diagnosed with MM, but data on the length of follow-up was incomplete and varied widely. Proportions of patients with CRC stages I-III that developed MM overall was 14.4%-26.1% in 10 studies. In relation to the enrollment period, a downward trend may be discernible.

Studies adopting a more appropriate analysis were highly heterogeneous, whereas uncertain data of partly inadequate studies may indicate that MM are overall declining.

There is uncertainty in the relative benefits and harms of hyperthermic intraoperative peritoneal chemotherapy (HIPEC) when added to cytoreductive surgery (CRS) +/- systemic chemotherapy or systemic chemotherapy alone in people with peritoneal metastases from colorectal, gastric, or ovarian cancers.

We searched randomized controlled trials (RCTs) in the medical literature until April 14, 2022 and applied methods used for high-quality systematic reviews.

We included a total of eight RCTs (seven RCTs included in quantitative analysis as one RCT did not provide data in an analyzable format). All comparisons other than ovarian cancer contained only one trial. For gastric cancer, there is high uncertainty about the effect of CRS + HIPEC + systemic chemotherapy. For stage III or greater epithelial ovarian cancer undergoing interval cytoreductive surgery, CRS + HIPEC + systemic chemotherapy probably decreases all-cause mortality compared to CRS + systemic chemotherapy. For colorectal cancer, CRS + HIPEC + systemic chemotherapy probably results in little to no difference in all-cause mortality and may increase the serious adverse events proportions compared to CRS +/- systemic chemotherapy, but probably decreases all-cause mortality compared to fluorouracil-based systemic chemotherapy alone.

The role of CRS + HIPEC in gastric peritoneal metastases is uncertain. CRS + HIPEC should be standard of care in women with stage III or greater epithelial ovarian cancer undergoing interval CRS. CRS + systemic chemotherapy should be standard of care for people with colorectal peritoneal metastases, with HIPEC given only as part of a RCT focusing on subgroups and regimes.

CRD42019130504.

Extended oncological resections for colorectal cancer surgery are associated with a high rate of complications, especially anastomotic leakage (AL). This study determines the incidence of risk factors for postoperative complications following cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) for colorectal cancer (CRC).

In this cohort study, the clinical data of all patients with CRC, treated with CRS and HIPEC, from 2011 to 2021 was analyzed. We considered patients' characteristics, tumor-specific features, postoperative complications, and hospital stay using Chi-Square-test or Fisher's exact test. The Mann-Whitney-U-test was used to measure the probability of differences between two sets of data.

Of 1089 HIPEC procedures performed in the study center, 185 patients with CRC and peritoneal metastasis were treated with CRS and HIPEC after formation of at least one anastomosis and therefore included in this study. This included synchronous and metachronous peritoneal metastasis with a mean peritoneal cancer index of 8.67 ± 5.22. In this cohort, AL occurred in 12 (6.5 %) patients. There was no correlation between the number of anastomoses and the occurrence of an AL (p = 0.401).

This study reports a low risk of AL after CRS with HIPEC for CRC, comparable to other published data. If a complete cytoreduction seems possible, the risk of anastomotic leakage should not negatively influence the decision to resect. Further studies on this subject are essential to validate our findings.