关键词: T4期结肠癌, 腹膜转移, 新辅助治疗, 腹腔镜手术, 联合器官切除, 腹腔热灌注化疗

Abstract: It is commonly held that the survival rate for patients with pT4a stage colon cancer surpasses those of the pT4b stage. However, certain empirical investigations have indicated that patients at the pT4a stage exhibit a higher prevalence of peritoneal metastasis, and the prognostic outcomes of patients at the pT4a stage are comparable or even inferior to those at the pT4b stage. Consequently, greater emphasis should be directed towards the preventive measures against peritoneal metastasis for individuals at the pT4a stage. Patients with T4b stage colon cancer may enhance local control and prolong survival through the performance of multivisceral resection. Moreover, neoadjuvant immunotherapy should be administered to those with dMMR colon cancer to elevate the rate of pathological complete response (pCR). For patients with pMMR type cT4a stage colon cancer, a course of neoadjuvant chemotherapy spanning three months should be administered. In the case of pMMR type cT4b stage colon cancer, it may be advisable to intensify the neoadjuvant treatment regimen and/or extend the duration of the chemotherapy cycles. Direct contact with the tumor should be avoided as much as possible to prevent peritoneal metastasis when patients at the T4a stage undergo laparoscopic surgery.The management of T4b stage colon cancer places a greater emphasis on such surgical interventions. Patients at the T4b stage should undergo careful selection for laparoscopic surgery. If the procedure cannot be completed laparoscopically, it is imperative to promptly convert to open surgery. For T4 colon cancer, it is advisable to perform hyperthermic intraperitoneal chemotherapy (HIPEC) preventively as soon as possible, either during or following the surgical intervention. Additionally, a pharmacological agent with a favorable tolerance profile should be chosen for the treatment. 

Key words: stage T4 colon cancer, peritoneal metastasis, neoadjuvant therapy, laparoscopic surgery, multivisceral resection, hyperthermic intraperitoneal chemotherapy