Outcomes of Locally Advanced Rectal Cancer Patients Following Complete Clinical Response After Neoadjuvant Treatment.

Background Watchful waiting and non-operative management of patients with complete clinical response to neoadjuvant treatment in locally advanced rectal cancers is an emerging practice now, especially in patients whose surgery would require permanent stoma. Methodology This is a retrospective study of patients presenting to the National Cancer Institute, Cairo University, Egypt from January 2005 to December 2019 with pathologically proven locally advanced rectal cancer who had a complete clinical response after neoadjuvant treatment. Patients who underwent surgery after achieving complete clinical response and patients who were kept under watchful waiting were compared in terms of overall survival (OS), disease-free survival (DFS), metastasis-free survival (MFS), and local recurrence-free survival (LRFS). Results Of the 51 patients identified, 31 (61%) went to surgery, and 20 (39%) were kept under watchful waiting. There was no difference in five-year OS between both groups (65% for both, p = 0.57). Five-year DFS for the watchful waiting group was 68% versus 62% for the surgery group (p = 0.75). Five-year LRFS was 100% in the watchful waiting group versus 83% in the surgery group (p = 0.15). Conclusions Watchful waiting after a complete clinical response to neoadjuvant treatment in locally advanced rectal cancer is feasible without compromising disease-related outcomes, especially in patients with distal rectal cancers requiring permanent stoma after surgery. However, further prospective validation is needed.