Paul Menzel, Abstract Co-Author: Nothing to Disclose

Justin Linam MA, MD, Presenter: Nothing to Disclose

Purpose/Objective(s):Neoadjuvant chemoradiotherapy (nCRT) and surgery is the standard of care for locally advanced rectal cancer (LARC), with pathologic complete response rates around 15%. Some patients with distal tumors and clinical complete response (cCR) after nCRT, however, refuse surgery, citing favorable disease attributes and fear of a permanent stoma. We hypothesize that such patients will have an elevated locoregional recurrence (LRR) rate but that most can be successfully salvaged if followed closely. We present here our experience offering active surveillance (AS) for distal LARC.Materials/Methods:This is multi-institutional review of two women and nine men at a median age of 61 years (range, 54-90) with T2-3N0-1M0 distal rectal adenocarcinoma who have been prospectively followed. All patients had cCR, including negative rectal biopsies, after 5-fluorouracil-based chemotherapy (5-FU CT) with 48.6-55.8 Gy (median, 50.4) concurrent radiotherapy (RT) and refused surgery. T3 and N1 patients also received adjuvant 5-FU CT. Following extensive counseling that nCRT alone is non-standard treatment, AS was offered in lieu of surgery. AS consisted of imaging, CEA levels, endoscopies, and clinical exams every 1-12 months, at decreasing intervals over time. Follow-up was calculated from the start of nCRT. Our primary interests were the LRR rate and success of salvage therapy among these patients.Results:At a median follow-up of 42 months (range, 23-134), 2 of 11 (18%) patients developed LRR. There were no distant recurrences or deaths. One recurrent patient presented with T3N0 disease, had a local recurrence (LR) at 11 months, and underwent salvage abdominoperineal resection. He remains disease-free 60 months later. The second recurrent patient presented with T2N0 disease, had a LR with presacral extension at 23 months, and received salvage brachytherapy. She has slowly progressive disease seven months later and continues to refuse surgery.Conclusions:Patients with distal LARC who exhibit cCR after nCRT and forgo surgery have a LRR rate near 20%, or at least twice that of those proceeding with surgery. Close follow-up is therefore critical in these patients. Despite producing only two failures, our review adds to the limited existing literature that suggests at least half of carefully selected LARC patients undergoing AS can be salvaged successfully. Additional studies are needed to define an optimal subset of LARC patients for AS; to establish an appropriate surveillance protocol for such patients, particularly in the first two years; and to evaluate the role of dose-escalation in nCRT for LARC, as recent radiobiological data suggest a significant dose-response up to 70 Gy in LARC. In the interim, distal LARC patients with cCR after nCRT who undergo AS appear to have an encouraging prognosis, and AS is reasonable for those declining surgery.

Menzel, P, Linam, J, Active Surveillance Following Neoadjuvant Chemoradiotherapy for Distal Rectal Tumors.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14042634.html