Clinical Trials Study Open Access
Copyright ©The Author(s) 2024. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Jan 7, 2024; 30(1): 79-90
Published online Jan 7, 2024. doi: 10.3748/wjg.v30.i1.79
Machine learning identifies the risk of complications after laparoscopic radical gastrectomy for gastric cancer
Qing-Qi Hong, He-Xin Lin, Jun You, Department of Gastrointestinal Oncology Surgery, The First Affiliated Hospital of Xiamen University, School of Medicine, Xiamen 361001, Fujian Province, China
Su Yan, Department of Gastrointestinal Surgery, Qinghai University Affiliated Hospital, Xining 810000, Qinghai Province, China
Yong-Liang Zhao, Department of General Surgery and Center of Minimal Invasive Gastrointestinal Surgery, The First Hospital Affiliated to Army Medical University, Chongqing 400038, China
Lin Fan, Department of General Surgery, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710061, Shaanxi Province, China
Li Yang, Department of General Surgery, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, Jiangsu Province, China
Wen-Bin Zhang, Department of Gastrointestinal Surgery, The First Affiliated Hospital of Xinjiang Medical University, Urmuqi 830054, Xinjiang Uygur Autonomous Region, China
Hao Liu, Guo-Xin Li, Department of General Surgery, Nanfang Hospital, Southern Medical University, Guangzhou 510515, Guangdong Province, China
Jian Zhang, Department of Gastrointestinal Surgery, Affiliated Hangzhou First People's Hospital, Zhejiang University School of Medicine, Hangzhou 310006, Zhejiang Province, China
Zhi-Jian Ye, Department of Gastrointestinal Surgery, Zhongshan Hospital of Xiamen University, Xiamen 361004, Fujian Province, China
Xian Shen, Department of Surgery, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou 325027, Zhejiang Province, China
Li-Sheng Cai, Department of General Surgery Unit 4, Zhangzhou Affiliated Hospital of Fujian Medical University, Zhangzhou 363000, Fujian Province, China
Guo-Wei Zhang, Department of Gastrointestinal Surgery, The Second Affiliated Hospital of Xiamen Medical College, Xiamen 361021, Fujian Province, China
Jia-Ming Zhu, Department of Gastrointestinal Nutrition and Hernia Surgery, The Second Hospital of Jilin University, Changchun 130041, Jilin Province, China
Gang Ji, Department of Digestive Diseases, Xijing Hospital, Air Force Military Medical University, Xi'an 710032, Shaanxi Province, China
Jin-Ping Chen, Department of Gastrointestinal Surgery, Quanzhou First Hospital Affiliated to Fujian Medical University, Quanzhou 362002, Fujian Province, China
Wei Wang, Department of Gastrointestinal Surgery, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou 510120, Guangdong Province, China
Zheng-Rong Li, Department of Gastrointestinal Surgery, The First Affiliated Hospital of Nanchang University, Nanchang 330006, Jiangxi Province, China
Jing-Tao Zhu, The Third Clinical Medical College, Fujian Medical University, Fuzhou 35000, Fujian Province, China
ORCID number: Hao Liu (0000-0001-6131-9398); He-Xin Lin (0000-0002-2328-8110); Li-Sheng Cai (0000-0003-1240-454X); Wei Wang (0000-0002-8515-7060); Guo-Xin Li (0000-0003-2773-7048); Jun You (0000-0002-4646-1422).
Co-first authors: Qing-Qi Hong and Su Yan.
Co-corresponding authors: Guo-Xin Li and Jun You.
Author contributions: Yan S, Li GX, You J, and Hong QQ contributed to the conception and design of the research; Hong QQ, Zhao YL, Lin F, Yang L, Zhang WB, Liu H, Lin HX, Zhang J, Ye ZJ, Shen X, Cai LS, Zhang GW, Zhu JM, Ji G, Chen JP, Wang W, Li ZR, Zhu JT, and Yan S contributed to the acquisition of data; Hong QQ, Zhao YL, Lin F, Yang L, Zhang WB, Liu H, Lin HX, Zhang J, Ye ZJ, Shen X, Cai LS, Zhang GW, Zhu JM, Ji G, Chen JP, Wang W, Li ZR, Zhu JT, Yan S, Li GX, and You J contributed to the analysis and interpretation of data; Hong QQ, Lin HX, and Zhu JT contributed to the statistical analysis; Lin HX, Hong QQ, and You J contributed to the obtaining funding; Hong QQ, Zhao YL, Lin F, Yang L, Zhang WB, Liu H, Lin HX, Zhang J, Ye ZJ, Shen X, Cai LS, Zhang GW, Zhu JM, Ji G, Chen JP, Wang W, Li ZR, Zhu JT, Yan S, Li GX, and You J contributed to the drafting the manuscript; Hong QQ, Zhao YL, Lin F, Yang L, Zhang WB, Liu H, Lin HX, Zhang J, Ye ZJ, Shen X, Cai LS, Zhang GW, Zhu JM, Ji G, Chen JP, Wang W, Li ZR, Zhu JT, Yan S, Li GX, and You J contributed to the revision of manuscript for important intellectual content; All authors have read and approve the final manuscript.
Supported by Natural Science Foundation of Fujian Province, No. 2021J011360, and No. 2020J011230; Natural Science Foundation of Xiamen, China, No. 3502Z20214ZD1018, and No. 3502Z20227096; Medical Innovation Project of Fujian Provincial Health Commission, No. 2021CXB019; Youth Scientific Research Project of Fujian Provincial Health Commission, No. 2022QNB013; and Bethune Charitable Foundation, No. HZB-20190528-10.
Institutional review board statement: The study was reviewed and approved by the The First Affiliated Hospital of Xiamen University Institutional Review Board, No. XMFHIIT-2023SL097.
Clinical trial registration statement: This study is registered at Chinese Clinical Trial Registry (www.chictr.org.cn). The registration identification number is ChiCTR2300078445.
Informed consent statement: All study participants or their legal guardian provided informed written consent about personal and medical data collection prior to study enrolment.
Conflict-of-interest statement: The authors declare no conflict of interest.
Data sharing statement: The data that support the findings of this study are available from the corresponding author.
CONSORT 2010 statement: The authors have read the CONSORT 2010 statement, and the manuscript was prepared and revised according to the CONSORT 2010 statement.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: https://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Jun You, PhD, Doctor, Department of Gastrointestinal Oncology Surgery, The First Affiliated Hospital of Xiamen University, School of Medicine, No. 55 Zhenhai Road, Xiamen 361001, Fujian Province, China. youjun@xmu.edu.cn
Received: August 30, 2023
Peer-review started: August 30, 2023
First decision: September 23, 2023
Revised: October 30, 2023
Accepted: December 19, 2023
Article in press: December 19, 2023
Published online: January 7, 2024

Abstract
BACKGROUND

Laparoscopic radical gastrectomy is widely used, and perioperative complications have become a highly concerned issue.

AIM

To develop a predictive model for complications in laparoscopic radical gastrectomy for gastric cancer to better predict the likelihood of complications in gastric cancer patients within 30 days after surgery, guide perioperative treatment strategies for gastric cancer patients, and prevent serious complications.

METHODS

In total, 998 patients who underwent laparoscopic radical gastrectomy for gastric cancer at 16 Chinese medical centers were included in the training group for the complication model, and 398 patients were included in the validation group. The clinicopathological data and 30-d postoperative complications of gastric cancer patients were collected. Three machine learning methods, lasso regression, random forest, and artificial neural networks, were used to construct postoperative complication prediction models for laparoscopic distal gastrectomy and laparoscopic total gastrectomy, and their prediction efficacy and accuracy were evaluated.

RESULTS

The constructed complication model, particularly the random forest model, could better predict serious complications in gastric cancer patients undergoing laparoscopic radical gastrectomy. It exhibited stable performance in external validation and is worthy of further promotion in more centers.

CONCLUSION

Using the risk factors identified in multicenter datasets, highly sensitive risk prediction models for complications following laparoscopic radical gastrectomy were established. We hope to facilitate the diagnosis and treatment of preoperative and postoperative decision-making by using these models.

Key Words: Gastric cancer, Laparoscopic radical gastrectomy, Postoperative complications, Laparoscopic total gastrectomy

Core Tip: This is a multicenter clinical study involving 17 Chinese medical centers, which uses machine learning methods to predict the risk of complications in laparoscopic gastric cancer surgery, contributing to the prevention and early warning of complications.



INTRODUCTION

Laparoscopic radical gastrectomy is currently recommended for the treatment of early-stage gastric cancer[1,2]. The safety of laparoscopic distal gastrectomy (LDG) for gastric cancer has been confirmed in studies by CLASS01, KLASS01, and JCOG0912, whereas CLASS02 and KLASS03 confirmed the efficacy of laparoscopic total gastrectomy (LTG)[3-7]. Safety studies on laparoscopic proximal gastrectomy in gastric cancer are also being conducted in medical centers with extensive laparoscopic expertise. Meanwhile, an increasing number of prospective and retrospective studies have confirmed the safety and efficacy of laparoscopy in the treatment of progressive gastric cancer[3,8,9]. However, laparoscopic radical surgery for progressive gastric cancer is not universally accepted or widely used. Complication rates are closely monitored by surgeons as a criterion for assessing surgical safety. The identification of patients at high risk of complications might allow the selection of a risk-adapted procedure and intervening perioperative measures to reduce complications and increase the confidence of the surgeon. As a result, many scoring systems to evaluate the safety of surgery have been created, such as physiological capacity and surgical stress assessments and surgical mortality scores, to predict the risk of postoperative complications[10,11]. Although these algorithms can identify complications, they lack specificity for laparoscopic radical gastric cancer surgery. There are two models for predicting the complications of laparoscopic gastric cancer surgery. One is the complication score constructed by Professor Chang-Ming Huang's team at Fujian Medical University Union Hospital[12], and the other is a scoring system constructed by Ohkura et al's team at Kyoto University Medical School Hospital in Japan[13]. Both models have excellent ability to predict complications. However, the data from previous studies were from a single center and had less external validation; thus, its applicability in different hospitals remains to be validated.

Early identification of patients with potentially high complication rates, elimination of risk factors for preoperative complications, guidance of intraoperative surgical decisions, and enhancement of early warning of postoperative complications are intended to improve the overall patient prognosis. Therefore, this study aimed to develop a multicenter model using three machine learning approaches to predict perioperative complication rates in patients undergoing LDG and LTG.

MATERIALS AND METHODS
Patient information

The training dataset included patients who underwent laparoscopic radical gastrectomy for gastric cancer from 2016 to 2020 at 16 medical centers in China, namely the First Affiliated Hospital of Army Medical University, the First Affiliated Hospital of Nanjing Medical University, the First Affiliated Hospital of Nanchang University, the First Affiliated Hospital of Xiamen University, the Affiliated Hospital of Qinghai University, the First Affiliated Hospital of Xinjiang Medical University, the First Affiliated Hospital of Xi'an Jiaotong University, Guangdong Provincial Hospital of Traditional Chinese Medicine, the Second Hospital of Jilin University, Xijing Hospital-the Air Force Military Medical University, the Second Hospital of Wenzhou Medical University, Zhongshan Hospital Xiamen University, Affiliated Hangzhou First People's Hospital with Zhejiang University School of Medicine, Zhangzhou Affiliated Hospital of Fujian Medical University, Quanzhou First Hospital affiliated to Fujian Medical University, and the second hospital affiliated to Xiamen Medical College. Validation datasets were obtained from gastric cancer patients undergoing laparoscopic radical gastrectomy at the Nanfang Hospital of Southern Medical University. Inclusion criteria: (1) Perioperative clinical stage ranging from T1a to T4a, N0 to N2, and M0; (2) Patients who underwent LTG or LDG combined with D2 Lymph node dissection and received a postoperative pathological diagnosis confirming R0 resection; (3) Postoperative pathological confirmation of gastric adenocarcinoma; and (4) The surgeons had extensive experience in laparoscopic gastric cancer, having completed at least 50 such cases. Exclusion criteria: (1) Intraoperative evidence of peritoneal dissemination, invasion of adjacent organs, or distant metastasis; (2) Combined multiorgan resection; (3) R1 or R2 resection; (4) Conversion to an open laparotomy; (5) Previous of malignancy; (6) History of abdominal surgery; and (7) Preoperative Neoadjuvant Therapy. The extent of lymph node dissection was based on the guidelines of the Japan Gastric Cancer Association. This study was approved by the Ethics Committee of the First Affiliated Hospital of Xiamen University.

Study variables

Study variables analyzed included age; sex; body mass index (BMI); American society of Aneshesiologists (ASA) score; Eastern Collaborative Oncology Group (ECOG) score; history of hypertension, diabetes, and severe cardiopulmonary disease; operative time; surgical bleeding volume; intraoperative blood transfusion; surgical approach; and method of gastrointestinal reconstruction. Complications were graded according to the Clavien–Dindo classification, where complications of grade 2 and above were defined as serious.

Model construction and evaluation

Normally distributed continuous variables are expressed as χ2 ± s, and an independent samples t-test was used for comparisons between groups. Skewed distribution measurement data are expressed as mean (median), and non-parametric tests were used for comparisons between groups. The categorized variables are expressed as frequencies, and the χ2 test and Fisher's exact probability method were used for comparisons between groups. The rank-sum test was used for hierarchical variables. Factors with a P value of < 0.05 for univariate analysis were further used for model construction of postoperative complications. The receiver operating characteristic curve and area under the curve (AUC) of the model validation results were used to evaluate predictive ability.

Lasso regression model construction

The “glmnet” R package was used to construct the Lasso regression model. The independent variables with P values < 0.05 in the logistic analysis were subjected to Lasso regression analysis, and the coefficients of the independent variables initially included in the model were gradually compressed as the penalty coefficient λ changed. Finally, the coefficients of some of the independent variables were compressed to zero to avoid overfitting the model. To find the best penalty coefficient λ for good model performance with the least impact, the value of λ + 1 with the least error in the ten-fold cross-validation method is chosen as the optimal value[14]. In the LTG and LDG models, the λ + 1 values were 0.0002534603 and 0.001445553, respectively (Supplementary Figure 1).

Random forest model construction

The “RandomForest” R package was used to construct a random forest model. Random forests involve multiple random data draws to generate many decision trees, and the results derived from these trees are combined to prevent model overfitting[15]. To build the final model, we used the minimum number of decision trees for which the error was stabilized. The model was constructed to rank the importance of variables in the random forest by using the improvement of the Gini index as an evaluation criterion for the importance of features (Supplementary Figure 2).

Artificial neural networks model construction

The “neuralnet” R package was used to construct a random forest model. The neural network mode transfers the rules hidden in the data to the network structure by processing the experimental data. An artificial neural network consists of three layers: Input, hidden, and output layers. The number of layers and neurons in the hidden layer are set according to actual requirements and experience[16]. To select the number of hidden layer neurons, the following empirical formula is used as a reference: Hh =Ns/[a × (Ni + No)], where Ni is the number of input layer neurons; No, number of output neurons; Ns, number of samples in the training set; and a, arbitrary value variable that can be taken by itself, typically ranging from 2 to 10.

RESULTS
Clinicopathological data of study subjects

A total of 998 and 398 patients were retrospectively included in the training and validation groups, respectively. The clinicopathological data of the patients are shown in Table 1. The research flow of this study is illustrated in Figure 1. There were 164 and 78 cases of serious complications in the modeling and validation groups, respectively (Table 2).

Figure 1
Figure 1 Research flow diagram. LTGC: Laparoscopic total gastrectomy for gastric cancer; LDGC: Laparoscopic distal gastrectomy for gastric cancer.
Table 1 Demographic and clinical characteristics of the training group and validation groups (mean ± SD).
CharacteristicTraining group
Validation group
LGC (n = 998)
LTG (n = 572)
LDG (n = 426)
LGC (n = 398)
LTG (n = 165)
LDG (n = 233)
Age59.8 (11.31)60.0 (11.22)59.6 (11.44)57.8 (12.4)59.2 (12.2)57.0 (12.4)
Gender
Female3071561511734582
male691416275342120151
BMI22.6 (3.2)22.9 (3.2)22.3 (3.2)22.6 (3.4)22.7 (3.6)22.5 (3.4)
ASA score
2964556408365148217
3341618331716
ECOG score
08104603501426973
1158986023189142
230141625718
Severe heart disease41322175
Severe lung disease105518126
Hypertension1407169783939
Diabetes673037522725
Operative time (min)240 (63.0)246.8 (73.1)230.9 (44.6)280.9 (76.4)308.0 (86.1)267.2 (68.9)
Bleeding volume (min)130.5 (115.4)147.8 (128.5)107.3 (90.0)54.3 (57.6)78.7 (67.4)57.9 (51.6)
Blood transfusion (mL)25.5 (138.1)34.3 (172.3)13.62 (67.9)19.0 (132.4)11.0 (65.1)22.0 (154.0)
Complication1396475785127
ClavienDindo
0859508351320114206
1145917107
2933459563818
329245532
4312000
Table 2 Incidence of complications in the training group and validation groups.

Training group
Validation group
Complication16478
Anastomotic leakage2311
Anastomotic stricture55
Anastomotic bleeding60
Pancreatic fistula30
Gastric and Intestinal stasis100
Bleeding of peritoneal cavity71
Surgical incision infection or fat liquefaction183
Pulmonary infection425
Abdominal infection2729
Sepsis50
Urinary tract infection113
Intestinal obstruction147
Lymphorrhea104
Deep vein thrombosis11
Pulmonary embolism11
Cardiac arrhythmia00
Biliary leakage10
Univariable analyses of complications in laparoscopic radical gastrectomy

The variables included in the model were initially screened using univariate analysis. The results of the univariate analysis of LDG suggested significant differences in age, BMI, intraoperative bleeding, history of severe pulmonary disease, ECOG score, and ASA score between the group with severe complications and the group without severe complications (P < 0.05) (Table 3). In the univariate analysis of LTG, age, ECOG score, ASA score, length of surgery, whether complete laparoscopic surgery was performed, and history of severe lung disease were significantly different between the group with severe complications and the group without severe complications (P < 0.05) (Table 4).

Table 3 Univariate analysis of severe complications after laparoscopic distal gastrectomy in gastric cancer patients.
Variate
No-severe complication (%)
Severe complication (%)
t/χ2
P value
OR
95%CI
Age group
Age ≤ 65239381.9050.168
Age > 65121281.4550.852-2.485
Gender
Male234410.0950.758
Female126251.1320.658-1.948
BMI group
BMI ≤ 28347579.490.002
BMI > 281394.2151.722-10.313
Hb129.7 ± 26.6126.8 ± 26.20.7970.4240.9960.986-1.006
ALB40.7 ± 4.8540.3 ± 4.030.7070.480.980.927-1.036
Tumor size3.2 ± 1.83.5 ± 2.0-1.3460.1791.1010.967-1.266
Bleeding volume103.3 ± 89.2128.6 ± 91.9-2.1090.0361.0031.000-1.005
Operative time230.7 ± 45.1232.4 ± 42.2-0.2820.7781.0010.995-1.007
Blood transfusion6.9 ± 49.8650.00 ± 121.8-27.381< 0.0011.0061.003-1.010
Severe heart disease
No359642.7480.064
Yes1211.2191.002-125.553
Severe lung disease
No358634.6010.032
Yes238.5241.396-52.039
Hypertension
No302550.0130.91
Yes58111.0410.541-2.109
Diabetes
No 329600.0160.899
Yes3161.0610.424-2.654
Surgerical type
Totally 82201.7340.188
Assisted278460.6780.380-1.212
Reconstruction
Billroth I90126.1330.105
Billroth II106261.8400.878-3.854
Roux-en-Y113241.5930.755-3.360
Billroth II + Braun5140.5880.180-19.19
ECOG score
03232795.605< 0.001
134269.1484.804-17.421
231351.84013.913-193.157
ASA score
23535529.802< 0.00110.0863.750-27.124
Table 4 Univariate analysis of severe complications after laparoscopic total gastrectomy in gastric cancer patients.
Variate
No-severe complication (%)
Severe complication (%)
t/χ2
P value
OR
95%CI
Age group
Age < 65332304.3810.036
Age ≥ 65181291.7331.032-3.047
Gender
Male372440.1130.736
Female141150.8990.485-1.667
BMI group
BMI ≤ 28481531.3190.251
BMI > 283261.7020.680-4.257
Hb129.1 ± 25.1135.2 ± 25.7-1.7540.081.010.999-1.021
ALB40.4 ± 3.139.7 ± 3.21.6640.0970.9280.851-1.013
Tumor size4.0 ± 2.23.8 ± 1.90.6740.5010.950.826-1.092
Bleeding volume150.2 ± 133.5130.2 ± 70.01.1140.2550.9980.995-1.001
Operative time248.9 ± 73.9229.0 ± 62.51.9830.0480.9960.991-1.000
Intraoperative blood transfusion37.1 ± 180.810.17 ± 54.8{0.099}0.7540.9980.995-1.002
Severe heart disease
No512590.1150.734
Yes10
Severe lung disease
No5115613.461< 0.001
Yes2313.6872.239-83.665
Hypertension
No452491.2450.264
Yes61101.5120.728-3.140
Diabetes
No489533.210.073
Yes2462.3070.902-5.896
Surgerical type
totally230354.4670.035
assisted283240.5570.322-0.964
ECOG
04263422.379< 0.001
177213.4171.883-6.199
21045.0121.493-16.824
ASA
25055128.024< 0.001
3889.9023.566-27.499
Prediction model for complications of laparoscopic radical gastrectomy

We constructed three machine-learning-based models to predict the risk of complications associated with laparoscopic radical gastrectomy for gastric cancer.

In the LASSO regression model of LTG, six variables were selected: Age group, history of severe lung disease, operative time, surgical type, ECOG score, and ASA score. The AUC of the LASSO regression prediction model for LTG was 0.743 (P < 0.0001) in the training group and 0.667 (P < 0.0001) in the validation group. In the LASSO regression model of LDG, six variables were selected: Age, BMI, intraoperative bleeding volume, history of severe lung disease, ECOG score, and ASA score (Supplementary Figure 1). The AUC of the LASSO regression prediction model for LDG was 0.800 (P < 0.0001) in the training group and 0.688 (P < 0.0001) in the validation group.

In the LTG random forest model, the number of decision trees used to construct the final random forest model was 53. In the LDG random forest model, when the number of decision trees is greater than 99, the error within the model tends to stabilize (Supplementary Figure 2). The AUC of the random forest prediction model for LTG was 0.8969 (P < 0.0001) in the modeling group and 0.7515 (P < 0.0001) in the validation group. In the random forest prediction model of LDG, the AUC of the model was 0.8853 (P < 0.0001) in the training group and 0.9025 (P < 0.0001) in the validation group. The AUC of the random forest prediction model for LTG was 0.9226 (P < 0.0001) in the training group and 0.7869 (P < 0.0001) in the validation group.

The input, hidden, and output layers in the LTG and LDG neural network models are shown in Supplementary Figure 3. The AUC of the neural network prediction model for LDG was 0.8451 (P < 0.0001) in the training group and 0.9142 (P < 0.0001) in the validation group. The AUC of the LTG prediction model was 0.8827 (P < 0.0001) in the training group and 0.747 (P < 0.0001) in the validation group.

DISCUSSION

Laparoscopic surgery is as safe and feasible as laparotomy in a variety of solid tumor radical procedures. The CLASS-01 study suggests that LDG is similar to open distal gastrectomy in terms of short-term outcomes, 3-year disease-free survival, and 5-year overall survival in gastric cancer patient[3,8]. The surgical indications for laparoscopic gastrectomy combined with D2 Lymph node dissection for gastric cancer remain controversial; however, the trend toward laparoscopic techniques seems irresistible. The accurate identification of postoperative complications could further improve the safety of laparoscopic techniques and expand their use in gastric cancer patients.

This study was based on retrospective data from multiple medical centers in multiple provinces in China, where all surgeons were skilled and experienced in laparoscopic techniques, which could eliminate the impact of the surgical learning curve. There are currently some documented omissions in Clavien–Dindo grade 1 surgical complications; therefore, this study focused on serious complications (Clavien–Dindo grade 2-5). The results of the univariate analysis in this study showed that age, history of severe lung disease, ECOG score, and ASA score were common risk factors for complications affecting laparoscopic gastric cancer surgery. ASA scores are used in an increasing number of centers for the pre- and postoperative management of surgical patients and are strongly associated with serious complications, morbidity, and mortality in surgical patients[17,18]. Similarly, this study found that patients with an ASA score of 3 had a much higher complication rate than those with an ASA score of 2. ECOG, a widely used measure of physical fitness recommended by the WHO, has been shown in several previous studies to be a risk factor for surgical complications after ovarian cancer reduction[19], laparoscopic hysterectomy[20], and radical nephrohysterectomy[21].

Several previous studies have suggested that patients with a high BMI have an increased risk of complications such as wound infection and intestinal obstruction owing to the accumulation of fat in the abdominal cavity, which affects lymph node dissection in gastric cancer and makes surgery more difficult[22,23]. However, in patients with a low BMI, esophagojejunostomy may be affected to some extent because of their smaller body size and narrow thorax; therefore, a high BMI in total gastrectomy did not show a significant risk. We also investigated the effect of the abdominal shape on the difficulty of surgery and the occurrence of complications in patients[24,25]. Therefore, subsequent studies incorporating factors related to body size are warranted.

Severe lung diseases considered in the study included obstructive emphysema, bronchial asthma, pneumonia, and pulmonary embolism. Laparoscopic surgery is likely to induce postoperative complications such as atelectasis, pulmonary infection, pulmonary edema, pulmonary embolism, and respiratory failure owing to continuous abdominal inflation, which is potentially more dangerous in the presence of an underlying lung disease. Therefore, in patients with a history of severe lung disease, the lung condition must be well-managed before performing laparoscopic surgery; otherwise, open surgery may be a more suitable option. Laparoscopic gastrectomy for gastric cancer is safe and reliable when the patient's general condition permits. For patients with severe underlying diseases, laparoscopic radical gastrectomy for gastric cancer should be performed with caution.

This study found that totally LTG was a risk factor for surgical complications, and whether this procedure can be safely conducted for gastric cancer patients remains uncertain. However, with the mastery of laparoscopic surgery, both the implantation of the anastomosis and suture anastomosis will no longer be difficult; rather, the totally laparoscopic technique can reduce the length of the abdominal incision and shorten the abdominal opening time. Future prospects are worth exploring in multicenter studies.

To guide clinical decision-making, sufficient preoperative preparation and perioperative monitoring should be performed for the high-risk population of gastric cancer postoperative complications, particularly cardiopulmonary function, identified in the construction model. If necessary, surgery should be postponed, and adequate monitoring of all aspects of the body and intervention in preoperative cardiopulmonary function should be performed in conjunction with consultations from various departments.

In this study, three machine learning methods were used to construct a complication prediction model for laparoscopic gastric cancer surgery, and all three methods showed good predictive performance both for laparoscopic distal gastric cancer radical surgery and for laparoscopic total gastric cancer radical surgery. The model prediction performance of random forest revealed certain advantages over the other two models; random forest model was more favorable for cases with discrete features, limited fetch values, and non-differentiability, among other reasons. The clinical data included in this study were primarily subtypes of variables, and the random forest model exhibited greater advantages in terms of predictive power when compared to all other models.

Compared to other laparoscopic gastrectomy complication models, this trial included medical institutions from different regions of China, and the validation set consisted of data from the main center of the CLASS-01, the Southern Hospital of Southern Medical University. The standardization of the validation dataset for surgery and the reliability of the data are guaranteed, which, to some extent, represents better applicability of the model for standardized laparoscopic gastric cancer surgery. This study also found that the prediction model was generally more effective in predicting complications of distal gastric radical surgery than of total gastric cancer radical surgery. This also indicates that laparoscopic distal gastric cancer surgery has become more consistent and standardized in most centers in China. In contrast, total gastric surgery has increased the confounding factors for complication prediction owing to the expansion and difficulty of the operation, which affects the predictive efficacy and indicates that the standardization of laparoscopic total gastric cancer radical surgery is still a work in progress. At present, the complications model of laparoscopic gastric cancer surgery based on artificial neural networks has been preliminarily applied in the main center for the early warning of preoperative patient complications. The specific benefits will be further reported through prospective research after expanding the sample size.

The present study had some limitations. Some patients were excluded from this study owing to the lack of a complication registry and clinicopathological data. Furthermore, this model is still in the exploratory stage, and its initial application is currently being launched at the main research center to extend the longitudinal depth of the data to be incorporated into the machine learning model. In the future, the model will be combined with an early warning system to assist in decision-making regarding clinical perioperative complications in gastric cancer patients.

CONCLUSION

The multicenter-based complication prediction scoring system constructed in this study can more accurately predict the occurrence of complications in patients. Such a prediction can help in the management of preoperative clinical risk factors and close monitoring of patients after surgery, which can improve the overall safety of surgery and lay the foundation for the widespread use of laparoscopic gastrectomy for gastric cancer.

ARTICLE HIGHLIGHTS
Research background

Laparoscopic radical gastrectomy is currently recommended for the treatment of early-stage gastric cancer. However, laparoscopic radical surgery for progressive gastric cancer is not universally accepted or widely used, potentially due to inadequate evaluation and prevention of surgical complications.

Research motivation

Preoperative general condition is an important factor affecting the complications of laparoscopic radical gastrectomy. Accurate prediction of complications can promote the application of laparoscopic radical gastrectomy for gastric cancer.

Research objectives

The aim of this study is to establish a complication prediction model, guide perioperative treatment strategies for gastric cancer patients, and prevent serious complications in laparoscopic radical gastrectomy.

Research methods

In total, laparoscopic radical gastrectomy for gastric cancer at 17 Chinese medical centers were included in complication model. Three machine learning methods, lasso regression, random forest, and artificial neural networks, were used to construct postoperative complication prediction models for laparoscopic distal gastrectomy and laparoscopic total gastrectomy, and their prediction efficacy and accuracy were evaluated.

Research results

The constructed complication model, particularly the random forest model, could better predict serious complications in gastric cancer patients undergoing laparoscopic radical gastrectomy.

Research conclusions

A highly sensitive risk prediction model for complications after laparoscopic radical gastrectomy has been established, and these models have been used to promote the diagnosis and treatment of preoperative and postoperative decisions.

Research perspectives

The complication warning function of this study has been integrated into the hospital internet warning system. In the future, the specific benefits of early warning systems will be further reported through prospective research after expanding the sample size.

Footnotes

Provenance and peer review: Unsolicited article; Externally peer reviewed.

Peer-review model: Single blind

Specialty type: Gastroenterology and hepatology

Country/Territory of origin: China

Peer-review report’s scientific quality classification

Grade A (Excellent): 0

Grade B (Very good): B, B

Grade C (Good): 0

Grade D (Fair): 0

Grade E (Poor): 0

P-Reviewer: Kotelevets SM, Russia; Shang L, China S-Editor: Fan JR L-Editor: A P-Editor: Zhao S

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