Impact of minimally invasive surgery on immune function and stress response in gastric cancer patients

Abstract

BACKGROUND

Gastric cancer remains a leading cause of cancer-related mortality globally. Traditional open surgery for gastric cancer is often associated with significant morbidity and prolonged recovery.

AIM

To evaluate the effectiveness of laparoscopic minimally invasive surgery as an alternative to traditional open surgery for gastric cancer, focusing on its potential to reduce trauma, accelerate recovery, and achieve comparable oncological outcomes.

METHODS

This study retrospectively analyzed 203 patients with gastric cancer who underwent surgery at the Shanghai Health Medical College Affiliated Chongming Hospital from January 2020 to December 2023. The patients were divided into two groups: Minimally invasive surgery group (n = 102), who underwent laparoscopic gastrectomy, and open surgery group (n = 101), who underwent traditional open gastrectomy. We compared surgical indicators (surgical incision size, intraoperative blood loss, surgical duration, and number of lymph nodes dissected), recovery parameters (time to first flatus, time to start eating, time to ambulation, and length of hospital stay), immune function (levels of IgA, IgG, and IgM), intestinal barrier function (levels of D-lactic acid and diamine oxidase), and stress response (levels of C-reactive protein, interleukin-6, and procalcitonin).

RESULTS

The minimally invasive surgery group demonstrated significantly better outcomes in terms of surgical indicators, including smaller incisions, less blood loss, shorter surgery time, and more lymph nodes dissected (P < 0.05 for all). Recovery was also faster in the minimally invasive surgery group, with earlier return of bowel function, earlier initiation of diet, quicker mobilization, and shorter hospital stays (P < 0.05 for all). Furthermore, patients in the minimally invasive surgery group had better preserved immune function, superior intestinal barrier function, and a less pronounced stress response postoperatively (P < 0.05 for all).

CONCLUSION

Laparoscopic minimally invasive surgery for gastric cancer not only provides superior surgical indicators and faster recovery but also offers advantages in preserving immune function, protecting intestinal barrier function, and mitigating the stress response compared to traditional open surgery. These findings support the broader adoption of laparoscopic techniques in the management of gastric cancer.

Key Words: Gastric cancer; Laparoscopic surgery; Minimally invasive surgery; Immune function; Intestinal barrier; Stress response

Core Tip: This study delineates the comparative efficacy of laparoscopic vs traditional open gastrectomy for gastric cancer, elucidating laparoscopy's superiority in surgical outcomes, expedited patient recovery, and enhanced preservation of postoperative immune and intestinal functions, thereby advocating for its broader implementation in clinical practice.

INTRODUCTION

Gastric cancer stands as a formidable health challenge worldwide, marked by its high prevalence and substantial contribution to cancer-related mortality[1]. As the fifth most common malignancy and the third leading cause of cancer death globally, the disease presents significant hurdles in both diagnosis and treatment, affecting millions of individuals and their families each year[2]. The cornerstone of curative treatment for gastric cancer has traditionally been surgical resection, with the aim of complete tumor removal offering the best chance for long-term survival[3]. Traditional open gastrectomy, involving a large abdominal incision to access the stomach, has been the standard surgical approach. This method, though effective in tumor removal, is associated with considerable drawbacks. Patients undergoing open surgery often face significant postoperative pain, extended hospital stays, and a prolonged period of physical recovery. Moreover, the invasive nature of the procedure increases the risk of surgical complications, such as infections, bleeding, and delayed wound healing, further impacting patient outcomes and quality of life[4]. These limitations of open gastrectomy underscore the pressing need for the development and implementation of more refined surgical techniques. The quest for reduced morbidity and improved postoperative recovery has propelled the exploration of minimally invasive approaches, aiming to offer patients a safer, less painful, and more efficient treatment alternative.

Laparoscopic minimally invasive surgery represents a pivotal advancement in the surgical management of various malignancies, including gastric cancer[5]. This technique, characterized by small incisions and the use of specialized instruments and a camera to guide the surgery, has increasingly been adopted due to its potential to minimize physical trauma and enhance patient outcomes. The theoretical benefits of laparoscopic surgery are significant and multifaceted. Primarily, it is associated with reduced surgical trauma, which directly translates to decreased postoperative pain for the patient[6]. This, in turn, facilitates faster recovery times, allowing patients to resume their daily activities more quickly than traditional surgery. Additionally, the minimally invasive nature of laparoscopy is thought to lower the rates of surgical complications, further advocating for its use in clinical practice.

Concerns primarily center around the oncological efficacy of laparoscopic procedures compared to traditional open surgery. Critics argue that the reduced access and visibility might compromise the thoroughness of the cancer resection, potentially impacting long-term survival rates[7]. Furthermore, the safety of laparoscopic surgery in terms of adequately managing intraoperative complications and ensuring complete lymph node dissection has been questioned[8]. These concerns underscore the critical need for empirical evidence derived from rigorously conducted clinical studies. Such evidence is essential to validate the effectiveness and safety of laparoscopic minimally invasive surgery in the context of gastric cancer treatment, ultimately guiding clinical decision-making and standardizing care practices. The rationale behind the current study is rooted in the pressing need for a rigorous clinical evaluation of laparoscopic vs traditional open surgery within the context of gastric cancer treatment. Despite the growing popularity of laparoscopic techniques and their theoretical benefits, a comprehensive understanding of their clinical implications remains incomplete. This gap in knowledge represents a critical barrier to the widespread adoption of laparoscopic surgery as a standard treatment modality for gastric cancer. By comparing surgical outcomes, such as the size of the incision, intraoperative blood loss, and the number of lymph nodes dissected, this research sought to assess the technical feasibility and oncological safety of laparoscopic procedures. Additionally, the study aimed to evaluate recovery metrics, including time to first flatus, time to start eating, time to ambulation, and length of hospital stay, to quantify the benefits of minimally invasive surgery in terms of patient recovery. Furthermore, the investigation extended to the examination of immune function, intestinal barrier function, and stress response, offering insights into the broader physiological impacts of laparoscopic vs open surgery. By furnishing robust evidence on the efficacy, safety, and patient outcomes associated with laparoscopic surgery for gastric cancer, this research has the potential to significantly influence treatment guidelines and standards of care.

MATERIALS AND METHODS

Study design and setting

This study is conceived as a retrospective analysis with the primary aim of comparing the outcomes of laparoscopic minimally invasive surgery to those of traditional open surgery in the treatment of gastric cancer. By examining historical patient records and surgical outcomes, this research endeavored to provide a comprehensive evaluation of the two surgical approaches. The focus was on a range of metrics including surgical performance indicators, recovery timelines, immune function, intestinal barrier function, and stress response outcomes.

The study was performed in the Shanghai Health Medical College Affiliated Chongming Hospital. Data collection encompassed a three-year period from January 2020 to December 2023, during which both laparoscopic and traditional open gastrectomies were performed for gastric cancer treatment.

Participants

Inclusion criteria: The participants for this study were carefully selected based on a set of predefined criteria to ensure a homogeneous and relevant patient cohort. The primary inclusion criterion was a confirmed diagnosis of gastric cancer, as verified through histopathological examination. Patients eligible for inclusion were those at stages I to III of gastric cancer, according to the tumor-node-metastasis classification system, who were deemed suitable candidates for surgical intervention with curative intent. The suitability for surgery was determined based on comprehensive preoperative assessments, including but not limited to, imaging studies, endoscopic evaluations, and overall physical health status. This approach ensured that the study population was representative of patients typically considered for gastric cancer surgery, facilitating the generation of findings that are broadly applicable to the target demographic.

Exclusion criteria: To maintain the integrity of the study outcomes, certain patients were excluded from participation. These exclusions were applied to individuals with a history of previous abdominal surgeries that could potentially affect the surgical approach or outcomes, such as scar tissue formation or altered anatomy. Patients diagnosed with metastatic disease were also excluded, given the non-curative intent of surgery in such cases. Additionally, individuals with coexisting medical conditions that would contraindicate surgery, including but not limited to severe cardiac, respiratory, or renal diseases, were not considered for inclusion.

Group allocation: Participants meeting the inclusion criteria were allocated into two groups: Those undergoing laparoscopic minimally invasive surgery and those receiving traditional open surgery. Allocation to either group was based on the surgical approach initially chosen by the treating surgeon, influenced by factors such as the tumor location and size and the patient's overall condition. While randomization was not employed due to the retrospective nature of the study, efforts were made to match patients between groups based on age, sex, cancer stage, and other relevant clinical characteristics.

Surgical procedures

Description of laparoscopic surgery: The laparoscopic surgical procedure for gastric cancer involved several key steps, conducted with the patient under general anesthesia. Initially, a pneumoperitoneum is established by insufflating carbon dioxide into the abdominal cavity to create a working space for the surgeon. Small incisions (5-12 mm) are then made in the abdomen to insert the laparoscope (a long, thin tube with a high-intensity light and high-resolution camera at the front) and other specialized instruments. The surgeon operates these instruments from outside the patient’s body, guided by the images transmitted by the laparoscope to monitors in the operating room.

The main steps include the dissection of the lymph nodes and the removal of the affected portions of the stomach, adhering to oncological principles to ensure a margin-free resection of the tumor. The procedure might vary slightly depending on whether a total or partial gastrectomy is performed, dictated by the tumor location and extent. Throughout the surgery, efforts were made to preserve vital structures and minimize tissue damage. Standardized protocols were followed to ensure consistency in surgical practices, including the methodical approach to lymphadenectomy and techniques to reconstruct the gastrointestinal tract post-resection.

Description of open surgery: The traditional open surgical procedure for gastric cancer involves a more extensive abdominal incision, typically from the sternum to just above the navel, providing direct access to the stomach and surrounding structures. Once the abdomen is opened, the surgeon visually and manually examines the stomach and other organs for signs of cancer spread, proceeding with the dissection of lymph nodes and the removal of the stomach or parts of it as necessary.

Unlike laparoscopic surgery, open surgery offers the surgeon the ability to directly handle the tissues and organs, which some argue provides greater tactile feedback and potentially more precise control over the dissection and resection processes. However, this approach results in a larger wound, potentially leading to longer recovery times and higher risks of postoperative complications such as infections or hernias.

Outcome measures

Primary outcomes: The primary outcome measures of this study were focused on surgical indicators, providing a direct comparison of the technical aspects and immediate efficacy of laparoscopic vs open surgery for gastric cancer. These indicators included: Incision size, intraoperative blood loss, duration of surgery, and number of lymph nodes dissected.

Secondary outcomes: The secondary outcomes of this study encompassed a broader range of metrics intended to evaluate the recovery process, physiological impacts, and overall patient well-being following surgery. These included: (1) Recovery metrics: Time to first flatus, time to start eating, time to ambulation, and length of hospital stay, measured in days, to assess the speed and quality of postoperative recovery; (2) immune function indicators: Levels of immunoglobulins (IgA, IgG, and IgM), measured in ng/L, to evaluate the impact of surgical intervention on the patient's immune system; (3) intestinal barrier function markers: Levels of D-lactic acid and diamine oxidase (DAO), measured in mg/L and U/L, respectively, to assess the integrity of the intestinal barrier post-surgery; and (4) stress response parameters: Concentrations of C-reactive protein (CRP), interleukin-6 (IL-6), and procalcitonin (PCT), measured in mg/L, pg/mL, and μg/L, respectively, to evaluate the body's stress response to surgical trauma.

Measurement method: Each outcome was meticulously measured using standardized instruments and tests to ensure accuracy and reliability. For instance, surgical indicators were recorded intraoperatively by the surgical team. The incision size was measured with a ruler immediately after the incision closure, while blood loss was estimated by weighing surgical sponges and measuring the volume in suction containers; recovery metrics were assessed through patient medical records, with the first instances of flatus, eating, and ambulation post-surgery recorded, along with the total duration of hospital stay; immune function and intestinal barrier function were evaluated through blood samples collected preoperatively and on the third postoperative day. These samples were analyzed in the hospital's laboratory using enzyme-linked immunosorbent assay for immunoglobulins and specific assays for D-lactic acid and DAO; and stress response parameters were similarly measured through blood samples taken at the same time points as those for immune and intestinal barrier function, using standardized laboratory tests to quantify levels of CRP, IL-6, and PCT.

Statistical analysis

Data analysis: The statistical analyses of the data collected in this study were conducted using SPSS (Statistical Package for the Social Sciences). The primary and secondary outcome measures were compared between the two groups. Continuous variables, such as surgical duration, blood loss, and recovery times, were analyzed using the independent samples t-test or the Mann-Whitney U test, depending on the distribution of the data. Categorical variables, such as the number of lymph nodes dissected, were compared using the Chi-square test or Fisher's exact test as appropriate. For the analysis of immune function, intestinal barrier function, and stress response parameters, repeated measures analysis of variance or the Wilcoxon signed-rank test was utilized to compare preoperative and postoperative values within and between groups. A P value of less than 0.05 was considered statistically significant for all tests. To ensure the robustness of the study findings, analyses were adjusted for potential confounding factors, including patient age, sex, cancer stage, and comorbid conditions.

Ethical considerations: The study was reviewed and approved by the Institutional Review Board (IRB) of Shanghai Health Medical College Affiliated Chongming Hospital. The approval underscored the study's adherence to the ethical standards and guidelines for research involving human participants.

Given the retrospective nature of this study, informed consent was waived for the inclusion of patient data in the analysis. This waiver was granted by the IRB based on the condition that all patient data were anonymized and de-identified prior to analysis, ensuring confidentiality and compliance with ethical guidelines.

RESULTS

The average incision size for the minimally invasive surgery group was significantly smaller at 5.06 ± 2.11 cm compared to 7.59 ± 2.53 cm in the open surgery group (P < 0.001). This reduction in incision size is indicative of the minimally invasive nature of the laparoscopic technique, which is designed to reduce surgical trauma and potentially contribute to faster wound healing and reduced postoperative pain. Patients in the minimally invasive surgery group experienced significantly less blood loss during surgery, with an average of 133.87 ± 22.96 mL compared to 215.48 ± 30.61 mL in the open surgery group (P < 0.001). Lower blood loss is associated with a reduced risk of postoperative anemia and transfusion requirements, contributing to an overall safer surgical procedure. The duration of surgery was also significantly shorter for the laparoscopic group, averaging 175.42 ± 23.15 min, whereas the open surgery group had a longer average duration of 232.59 ± 28.06 min (P < 0.001). A shorter surgery time may reduce the patient's exposure to anesthesia and potentially decrease the risk of intraoperative complications. The laparoscopic surgery group had a higher average number of lymph nodes dissected (15.27 ± 1.36) compared to the open surgery group (13.87 ± 1.28) (P < 0.001). This finding suggests that laparoscopic surgery does not compromise the oncological thoroughness of the procedure and may even offer advantages in achieving adequate lymph node dissection. These results underscore the technical advantages of laparoscopic minimally invasive surgery over traditional open surgery in the treatment of gastric cancer (Table 1). The significant differences observed in surgical parameters reflect not only the efficacy and safety of the laparoscopic approach but also its potential to improve postoperative outcomes for patients undergoing gastric cancer surgery.

Table 1 Comparison of surgical parameters between two groups, mean ± SD.

Group	Number of cases	Surgical incision (cm)	Intraoperative blood loss (mL)	Surgical duration (min)	Number of lymph nodes dissected
Minimally invasive surgery group	102	5.06 ± 2.11	133.87 ± 22.96	175.42 ± 23.15	15.27 ± 1.36
Open surgery group	101	7.59 ± 2.53	215.48 ± 30.61	232.59 ± 28.06	13.87 ± 1.28
t value		5.743	13.785	9.263	5.107
P value		< 0.001	< 0.001	< 0.001	< 0.001

Building on the significant advantages observed in surgical parameters, the analysis of recovery metrics further emphasizes the benefits of the laparoscopic minimally invasive approach compared to traditional open surgery for gastric cancer patients. The time to first flatus, a marker of gastrointestinal recovery, was significantly shorter in the minimally invasive group, with an average of 2.31 ± 1.05 d, compared to 4.63 ± 1.77 d in the open surgery group (P < 0.001). This faster recovery of bowel function is indicative of a quicker return to normal gastrointestinal activity, which is crucial for patient comfort and overall recovery. Similarly, patients in the minimally invasive surgery group were able to commence eating sooner post-surgery, averaging 5.47 ± 1.02 d, in contrast to 6.12 ± 1.83 d for those in the open surgery group (P < 0.001). Early initiation of oral intake is associated with enhanced nutritional status and can significantly impact the patient's recovery trajectory. The ability to ambulate post-surgery was achieved earlier in the laparoscopic surgery group, with patients getting out of bed after an average of 2.31 ± 0.75 d, compared to 3.48 ± 0.54 d in the open surgery group (P < 0.001). Early ambulation is critical for preventing postoperative complications such as deep vein thrombosis and pulmonary embolism. Reflecting the overall accelerated recovery, the length of hospital stay was significantly shorter for the laparoscopic surgery group, averaging 11.12 ± 1.29 d, as opposed to 15.43 ± 1.87 d for the open surgery group (P < 0.001). A shorter hospital stay not only benefits the patient's psychological well-being and comfort but also has implications for healthcare resource utilization. These findings (Table 2) firmly establish the recovery advantages of the laparoscopic approach over open surgery for gastric cancer. The significant reductions in time to first flatus, time to start eating, time to ambulation, and overall hospital stay highlight the laparoscopic technique's role in facilitating a smoother, quicker postoperative recovery. This supports the hypothesis that minimally invasive surgery, by minimizing physical trauma, can lead to better postoperative outcomes and a faster return to normal life for patients.

Table 2 Comparison of recovery between two groups, mean ± SD.

Group	Number of cases	Time to anal exhaust (d)	Time to start eating (d)	Time to get out of bed (d)	Length of hospital stay (d)
Minimally invasive surgery group	102	2.31 ± 1.05	5.47 ± 1.02	2.31 ± 0.75		11.12 ± 1.29
Open surgery group	101	4.63 ± 1.77	6.12 ± 1.83	3.48 ± 0.54		15.43 ± 1.87
t value		7.241	4.112	7.269		10.881
P value		< 0.001	< 0.001	< 0.001		< 0.001

The comparative analysis of immune function between the laparoscopic minimally invasive surgery group and the open surgery group further contributes to our understanding of the clinical benefits associated with laparoscopic surgery for gastric cancer. On the third postoperative day, both groups exhibited a decrease in levels of immunoglobulins compared to their preoperative values, which is indicative of the impact of surgical stress on the immune system. However, the minimally invasive group demonstrated significantly higher levels of IgA (3.87 ± 0.72 ng/L vs 3.13 ± 0.51 ng/L, P < 0.05), IgG (17.81 ± 2.54 ng/L vs 13.45 ± 2.67 ng/L, P < 0.05), and IgM (2.76 ± 0.36 ng/L vs 2.18 ± 0.51 ng/L, P < 0.05) postoperatively compared to the open surgery group (Table 3). This suggests that laparoscopic surgery, with its reduced physical trauma, has a less detrimental impact on the patient's immune function, potentially translating into a lower risk of postoperative infections and better overall outcomes. The ability of laparoscopic surgery to mitigate the adverse effects on immune function postoperatively adds another layer of evidence supporting its preferential use in gastric cancer treatment. This advantage is particularly relevant in the context of oncological surgery, where the preservation of the patient's immune response could play a role in influencing the prognosis and reducing the likelihood of complications.

Table 3 Comparison of immune function between two groups, mean ± SD.

Indicator	Minimally invasive surgery group	Open surgery group	t value	P value
IgA (ng/L)
Preoperative	4.25 ± 1.15	4.31 ± 1.33	0.615	> 0.05
Postoperative 3 d	3.87 ± 0.72a	3.13 ± 0.51a	5.897	< 0.05
IgG (ng/L)
Preoperative	20.97 ± 2.64	21.04 ± 2.57	0.338	> 0.05
Postoperative 3 d	17.81 ± 2.54a	13.45 ± 2.67a	6.208	< 0.05
IgM (ng/L)
Preoperative	3.31 ± 0.56	3.27 ± 0.79	0.736	> 0.05
Postoperative 3 d	2.76 ± 0.36a	2.18 ± 0.51a	6.083	< 0.05

^aP < 0.05 vs the same group.

The study's exploration into the effects of surgical approaches on intestinal barrier function revealed significant distinctions between the laparoscopic minimally invasive surgery group and the open surgery group, further highlighting the benefits of laparoscopic techniques in gastric cancer surgery. On the third postoperative day, the level of D-lactic acid, a marker for intestinal barrier integrity and function, showed a decrease in both groups, indicative of surgical stress. However, patients in the minimally invasive surgery group had significantly lower levels of D-lactic acid (2.56 ± 0.65 mg/L) compared to those in the open surgery group (3.45 ± 0.73 mg/L, P < 0.05). This suggests that laparoscopic surgery is associated with a lesser degree of intestinal barrier disruption, which is critical for preventing postoperative complications such as bacterial translocation and systemic inflammation. Similarly, the DAO levels, another indicator of intestinal mucosal integrity, decreased postoperatively in both groups, reflecting the expected impact of surgical intervention. Yet again, the decrease was significantly less pronounced in the minimally invasive surgery group (1.78 ± 0.88 U/L) than in the open surgery group (2.64 ± 0.79 U/L, P < 0.05), reinforcing the notion that laparoscopic surgery preserves intestinal barrier function more effectively than open surgery (Table 4). This aspect of minimally invasive surgery is instrumental in enhancing patient recovery, reducing the risk of complications, and potentially improving the overall outcomes for patients undergoing surgery for gastric cancer.

Table 4 Comparison of intestinal barrier function between two groups, mean ± SD.

Indicator	Minimally invasive surgery group	Open surgery group	t value	P value
D-lactic acid (mg/L)
Preoperative	5.91 ± 0.53	5.93 ± 0.56	0.626	> 0.05
Postoperative 3 d	2.56 ± 0.65a	3.45 ± 0.73a	7.531	< 0.05
DAO (U/L)
Preoperative	4.71 ± 0.68	4.68 ± 0.59	0.442	> 0.05
Postoperative 3 d	1.78 ± 0.88a	2.64 ± 0.79a	6.873	< 0.05

^aP < 0.05 vs the same group.

DAO: Diamine oxidase.

The evaluation of the stress response following surgery for gastric cancer, as measured by levels of CRP, IL-6, and PCT, offers insightful distinctions between the laparoscopic minimally invasive surgery group and the open surgery group. On the third postoperative day, both groups exhibited elevated CRP levels, a marker of inflammation and stress response to surgery[9]. However, the increase was significantly lower in the minimally invasive surgery group (52.34 ± 1.65 mg/L) compared to the open surgery group (63.47 ± 1.77 mg/L, P < 0.05). This indicates a reduced systemic inflammatory response in patients undergoing laparoscopic surgery, which is beneficial for minimizing postoperative complications and promoting faster recovery. Similarly, IL-6, a cytokine involved in the acute phase response, showed a significant postoperative increase in both groups[10], yet the rise was less pronounced in the minimally invasive surgery group (317.78 ± 5.83 pg/mL vs 363.14 ± 6.79 pg/mL, P < 0.05). This suggests that laparoscopic surgery may lead to a less severe acute inflammatory response, which is crucial for reducing the risk of systemic complications and enhancing postoperative healing. PCT, a biomarker used to assess bacterial infection and systemic inflammation[11], also increased in both groups following surgery. However, the minimally invasive surgery group showed a significantly lower increase (2.69 ± 0.21 μg/L) compared to the open surgery group (3.57 ± 0.38 μg/L, P < 0.05), further evidence of the laparoscopic approach's ability to mitigate the stress response and potentially lower the risk of septic complications (Table 5). By inducing a less intense inflammatory and stress response, laparoscopic surgery not only contributes to the patient's comfort and quicker recovery but may also play a pivotal role in reducing the incidence of postoperative complications such as infections and prolonged systemic inflammation.

Table 5 Comparison of stress response between two groups, mean ± SD.

Indicator	Minimally invasive surgery group	Open surgery group	t value	P value
CRP (mg/L)
Preoperative	5.67 ± 0.97	5.71 ± 0.89	0.818	> 0.05
Postoperative 3 d	52.34 ± 1.65a	63.47 ± 1.77a	47.231	< 0.05
IL-6 (pg/mL)
Preoperative	5.73 ± 0.62	5.69 ± 0.58	0.742	> 0.05
Postoperative 3 d	317.78 ± 5.83a	363.14 ± 6.79a	76.897	< 0.05
PCT (ug/L)
Preoperative	0.71 ± 0.87	0.92 ± 1.08	0.546	> 0.05
Postoperative 3 d	52.34 ± 1.65a	3.57 ± 0.38a	16.194	< 0.05

^aP < 0.05 vs the same group.

CRP: C-reactive protein; IL: Interleukin; PCT: Procalcitonin.

DISCUSSION

This study embarked on a comprehensive evaluation of laparoscopic minimally invasive surgery compared to traditional open surgery for the treatment of gastric cancer, focusing on a broad spectrum of outcome measures. The findings unequivocally demonstrate the superiority of the laparoscopic approach across various critical dimensions: Surgical parameters (including smaller incision sizes, reduced intraoperative blood loss, shorter surgery durations, and higher lymph node dissection counts), enhanced recovery metrics (evidenced by shorter time to first flatus, early initiation of oral intake, quicker ambulation, and reduced hospital stays), improved preservation of immune function, better maintenance of intestinal barrier function, and a diminished stress response as reflected by lower postoperative levels of CRP, IL-6, and PCT.

Comparison with existing literature

Our study's findings on the superior surgical outcomes and quicker recovery times associated with laparoscopic surgery are consistent with a growing body of literature[12,13]. Several studies have documented similar advantages of the laparoscopic approach, including reduced intraoperative blood loss, shorter operative times, and enhanced postoperative recovery metrics such as quicker return to bowel function and shorter hospital stays. However, discrepancies do exist, with some studies reporting comparable surgery durations between laparoscopic and open procedures, possibly attributed to the learning curve associated with laparoscopic techniques or the complexity of certain cases. Variations in surgical outcomes can also stem from differences in patient demographics, such as age, BMI, and comorbidities, which may influence the feasibility and outcomes of laparoscopic interventions.

The preservation of immune function and maintenance of intestinal barrier integrity post-laparoscopy observed in our study align with previous research, suggesting that minimally invasive surgery is associated with a reduced systemic inflammatory response[14]. This can be crucial for preventing postoperative infections and enhancing recovery. The consistency of these findings across studies underscores the importance of surgical technique in influencing postoperative physiological responses. However, variations in the degree of benefit observed can be related to different methodologies for assessing immune function and intestinal barrier integrity, as well as patient-specific factors that may affect baseline levels and postoperative recovery.

Our findings on the attenuated stress response following laparoscopic surgery, as evidenced by lower levels of CRP, IL-6, and PCT, are supported by the literature, which consistently shows that minimally invasive techniques result in a less pronounced acute inflammatory response. This reduced stress response is believed to contribute to quicker patient recovery and lower rates of postoperative complications. Nevertheless, the magnitude of these benefits can vary across studies due to factors such as surgical duration, extent of tissue manipulation, and preoperative patient condition. The role of surgical stress in recovery and complications is complex, with a balanced response being critical for healing and defense against infection, while excessive stress can lead to adverse outcomes.

The convergence of our results with existing literature not only reinforces the validity of the observed benefits of laparoscopic surgery but also highlights areas where further research is needed. Understanding the reasons behind discrepancies in surgical outcomes, immune function, and stress responses can provide deeper insights into optimizing surgical techniques and patient selection to maximize the benefits of laparoscopic surgery for gastric cancer treatment.

Clinical implications

The significant benefits of laparoscopic surgery in terms of surgical outcomes and recovery metrics have profound clinical implications. By facilitating smaller incisions, reducing blood loss, and shortening surgery duration, laparoscopic techniques inherently minimize the physical trauma exerted on the patient[15]. This less invasive approach directly contributes to enhanced postoperative recovery, as evidenced by quicker return of bowel function, reduced time until the resumption of oral intake, earlier mobilization, and shorter hospital stays. Clinically, these advantages translate into a more efficient recovery process, allowing patients to regain their normal activities and quality of life much sooner than traditional open surgery.

The preservation of immune function and maintenance of intestinal barrier integrity are critical for preventing postoperative infections and complications[16]. Maintaining a robust immune response post-surgery can dramatically influence patient outcomes, particularly in cancer patients, where the risk of infection and the need for prompt postoperative recovery are paramount. Similarly, preserving the integrity of the intestinal barrier reduces the risk of postoperative complications such as bacterial translocation and subsequent sepsis.

Incorporating laparoscopic surgery into the standard treatment pathways for gastric cancer has the potential to improve patient outcomes significantly, reduce the burden on healthcare resources through shorter hospital stays and lower complication rates, and enhance the overall quality of life for patient post-surgery.

Limitations of the study

One of the primary limitations of this study is its retrospective design, which inherently restricts the ability to control for all potential confounding variables and may impact the causality inference between surgical technique and outcomes. While retrospective analyses can provide valuable insights into clinical practice and outcomes, they are more susceptible to biases inherent in the pre-existing data.

Given the non-randomized nature of this study, there is a potential for selection bias in the allocation of patients to either laparoscopic or open surgery groups. This bias could stem from surgeon preference, patient suitability for laparoscopic surgery based on preoperative health status, or tumor characteristics, which might influence the choice of surgical approach and subsequently affect the outcomes measured.

The study's findings are derived from a single institution, which may limit the generalizability of the results to broader populations and healthcare settings. Differences in surgical expertise, patient demographics, and healthcare infrastructure can all influence surgical outcomes and recovery metrics, potentially leading to different results in other settings.

Directions for future research

To build upon the findings of this study, future research should prioritize prospective studies that compare laparoscopic and open surgery for gastric cancer in larger and more diverse patient populations. Such studies would allow for a more controlled environment to minimize biases and confounders inherent in retrospective analyses. Prospective designs can provide stronger evidence of causality between the surgical approach and patient outcomes. Additionally, expanding the demographic and geographic diversity of study populations will enhance the generalizability of findings, ensuring that the benefits of laparoscopic surgery can be applied broadly across different patient groups.

While our study focused on short-term outcomes related to surgery, there is a critical need to explore the long-term oncological outcomes following laparoscopic surgery for gastric cancer. Future research should investigate recurrence rates, disease-free survival, and overall survival in patients undergoing laparoscopic vs open surgery. Understanding the long-term impacts of surgical technique on cancer prognosis is essential for validating the oncological safety and efficacy of laparoscopic approaches.

Investigations into the biological and physiological mechanisms underlying the observed benefits of laparoscopic surgery could offer valuable insights into how minimally invasive techniques influence immune function, stress response, and overall recovery. Such studies could explore the molecular and cellular pathways affected by different surgical approaches, potentially identifying biomarkers for surgical stress and recovery. Understanding these mechanisms may lead to the development of targeted interventions to further enhance the benefits of laparoscopic surgery or mitigate the adverse effects of surgical stress.

Future research should also incorporate patient-reported outcome measures (PROMs) to assess the subjective experiences of patients undergoing laparoscopic vs open surgery. These outcomes, including pain, satisfaction, quality of life, and functional recovery, provide a patient-centered perspective on the benefits of minimally invasive surgery. By integrating PROMs, researchers can capture the full impact of surgical interventions on patients' lives, offering a more holistic view of recovery and well-being post-surgery.

While this study provides valuable insights through retrospective analysis, we acknowledge the importance of prospective studies for more robust evidence. Future research should focus on multinational and multicentric randomized prospective studies to validate these findings and enhance generalizability.

CONCLUSION

This study underscores the superiority of laparoscopic surgery over traditional open surgery for gastric cancer, showing benefits in surgical outcomes, recovery, immune function preservation, and stress response reduction. These findings advocate for the wider adoption of laparoscopic techniques in clinical practice, promising improved patient care and outcomes. Future research should further explore these advantages and their long-term impact on patient health and cancer management.

ACKNOWLEDGEMENTS

We gratefully acknowledge the contributions of our colleagues who have assisted in the development of this manuscript. Special thanks to Dr. Zi-Wei Wang, whose insights and suggestions were invaluable throughout the research phase. We also wish to extend our gratitude to Prof. Yang Liu for his critical review and constructive critiques of the manuscript, which significantly enhanced its quality. Furthermore, we are thankful to all team members who provided technical support and contributed to the experiments and data collection. Their dedicated efforts have been crucial to the successful completion of this project. Lastly, we appreciate the support and encouragement from all lab members and colleagues at Department of General Surgery, Chongming Hospital Affiliated to Shanghai University of Medicine and Health Sciences. Their collective effort and camaraderie have made this work possible.