Long‐Term Prognosis, Residual Recurrence Risk, and Postoperative Management After Pathological Complete Response in Rectal Cancer

ABSTRACT Patients with rectal cancer who achieve a pathological complete response (pCR) after neoadjuvant therapy and radical surgery generally have excellent long‐term outcomes, although a small proportion experience recurrence, predominantly at distant sites and within the first few postoperative years. Studies restricted to post‐pCR populations have evaluated carcinoembryonic antigen, anatomic variables, pretreatment magnetic resonance imaging features, acellular mucin, inflammatory markers, and other variables in relation to recurrence. Reported associations vary across cohorts, and no post‐pCR model has yet been externally validated for routine use. Postoperative circulating tumor DNA (ctDNA) is associated with recurrence in broader locally advanced rectal‐cancer cohorts, whereas pCR‐specific data remain limited. Emerging multimodal approaches integrating clinical, imaging, pathological, and molecular data may further refine post‐pCR risk stratification, although dedicated external validation remains necessary. Studies of adjuvant chemotherapy after conventional chemoradiotherapy report inconsistent recurrence outcomes and occasional overall‐survival associations, whereas evidence after completed total neoadjuvant therapy is more limited. In the absence of pCR‐specific surveillance trials, follow‐up is based on rectal‐cancer guidelines. Selected patients with limited recurrence may still be treated with curative intent. This review summarizes prognosis, reported risk factors, postoperative treatment, surveillance, and management after recurrence in patients with surgically confirmed ypT0N0.