Circumferential margin involvement shapes outcomes in rectal cancer

A study of 3,020 stage III rectal cancer patients identified that 12.4% had a positive circumferential resection margin (CRM). Notably, CRM involvement predominantly occurred through primary tumor invasion (63.2%). Local recurrence and distant metastasis rates varied, being lowest with lymph node metastasis and highest with multiple factors. Multivariate analysis revealed that primary tumor invasion, tumor deposits, and multiple factors correlated with poor overall survival, emphasizing the need for precise reporting of CRM involvement in treatment strategies.