Surveillance after neoadjuvant therapy in advanced rectal cancer with complete clinical response can have comparable outcomes to total mesorectal excision

While the standard of care for patients with rectal cancer who sustain a complete clinical response (cCR) to chemoradiotherapy (CRT) remains proctectomy with total mesorectal excision, data suggests that non-operative management may be a safe alternative. The purpose of this study is to compare outcomes between patients treated with CRT that attained a cCR and opted for a vigilant surveillance to those of the patients who had a complete pathologic response (cPR) following proctectomy. This is a retrospective review of patients treated for adenocarcinoma of the rectum who achieved either a cCR or a cPR following CRT. Patients with a cCR were enrolled in an active surveillance program which included regularly scheduled exams, proctoscopy, serum carcinoembryonic antigen (CEA), endorectal ultrasound, and cross-sectional imaging. Outcomes were compared to those patients who underwent proctectomy with a cPR. Our primary outcome measures were post-treatment complications, recurrence, and survival. We reviewed 18 patients who opted for surveillance after cCR and 30 patients who underwent proctectomy after a cPR. No non-operative patients had a documented treatment complication, while 17 patients with cPR suffered significant morbidity. There were two recurrences in the active surveillance group, one local and once distant, both treated by salvage resection with no associated mortality at 54 and 62 months. In the cPR group, one patient had a distant recurrence 24 months after surgery which was managed non-operatively. This patient died of unrelated causes 35 months after surgery. Active surveillance can be a safe option that avoids the morbidity associated with proctectomy and preserves oncologic outcomes.