Outcomes of Postchemoradiotherapy Watch-and-Wait Strategy in Patients With Rectal Cancer: A 20-Year, Single-Center Study

Background and objectives: The watch-and-wait (WW) strategy is a nonsurgical alternative for patients with rectal cancer exhibiting an excellent response to chemoradiotherapy. Studies on the WW strategy have primarily investigated 5-year oncological outcomes; few have focused on longer-term outcomes or the optimal patient selection approach for this therapeutic strategy.

Methods: This retrospective study enrolled patients with locally advanced rectal adenocarcinoma who had achieved complete response after chemoradiotherapy. Patients who achieved pathological complete response were categorized into a control group (n = 95) and those who achieved clinical complete response and were managed using the WW strategy were categorized into a case group (n = 33). Kaplan-Meier estimates were calculated for the between-group comparison of survival.

Results: The median follow-up duration was 89 months. Compared with the control group, the case group exhibited improved long-term sphincter preservation, particularly for low-lying tumors (p = 0.032), and inferior nonlocal-regrowth disease-free survival (p = 0.007). Within the case group, patients achieving a complete response by positron emission tomography exhibited 5-year survival rates similar to those achieving a complete endoscopic response.

Conclusion: The WW strategy is associated with improved sphincter preservation but worse nonlocal-regrowth disease-free survival. The potential of PET in patient selection for this strategy deserves further investigation.