Minimally invasive surgery versus laparotomy of nonmetastatic pT4a colorectal cancer: a propensity score analysis

AIM: The aim was to compare short-term and long-term oncological outcomes between minimally invasive surgery (MIS group) and laparotomy (lap group) in nonmetastatic pT4a colorectal cancer (CRC). MATERIALS AND METHODS: The study retrospectively analyzed the outcomes of 634 patients treated with radical operation from January 2015 to December 2021 for nonmetastatic pT4a CRC, with propensity score matching. RESULTS: The conversion rate from the MIS group to laparotomy is 3.5%. Intraoperative blood loss, time to first anal exhaust, defecation and drainage tube removal, and complication rate were significantly less in the MIS group. After 5 years, the outcomes of the MIS group were no inferior to laparotomy outcomes [overall survival (OS): 72.7 vs. 77.8%, P=0.285; disease-free survival (DFS): 72.2 vs. 75.0%, P=0.599]. And multivariate analysis showed that age greater than or equal to 60 years old, lymph node metastasis and the carcinoembryonic antigen levels were independent variables for OS, while lymph node metastasis and CA125 levels were independent variables for DFS. The results of the graph show the relationship between the sum of scores of sex, age, complications, BMI, carcinoembryonic antigen, age, CA125, tumor site, N stage and tumor length diameter and 1-year, 3-year, and 5-year mortality and DFS of patients. Among them, tumor length diameter and N stage are significantly correlated with long-term survival and disease-free of patients. CONCLUSION: MIS is safe and feasible for nonmetastatic pT4a CRC, with the added benefit of accelerated postoperative recovery. In oncology, MIS did not affect OS and DFS.