Preoperative short- vs. long-course chemoradiotherapy with delayed surgery for locally advanced rectal cancer.

Purpose: To compare the clinical outcomes between short-course chemoradiotherapy (CRT) and long-course CRT with delayed surgery in locally advanced rectal cancer patients. Results: From 2010 to 2015, 19 patients were treated with short-course CRT and 53 patients were treated with LCRT. The sphincter-saving rate (89.5% vs. 94.3%, short-course CRT vs. long-course CRT), pathologic complete remission (21.1% vs. 13.2%), downstaging (47.4% vs. 26.4%), and treatment complications including anastomotic site leakage, bowel adhesion, and hematologic toxicity associated with short-course CRT were not significantly different from those associated with long-course CRT. 2-year overall survival was 90.0% and 91.2% (p = 0.448), respectively. Methods and materials: 72 patients with stage cT3-4N0-2M0 rectal cancer participated in a multicenter study. Short-course CRT treatment was as follows: a total of 25 Gy of radiotherapy was delivered in 5 equal doses with intensity modulated radiation therapy. Chemotherapy was consisted of Leucovorin 400 mg/m(2) administered by bolus injection on day 1 and 5-Fluouracil 1200 mg/m(2) given by continuous infusion on days 1 and 2. An additional three cycles of chemotherapy were administered before the surgery. Long-course CRT treatment was as follows: a total of 50.4 Gy of radiotherapy was delivered in 28 equal doses. Chemotherapy consisted of a bolus injection of 5-Fluouracil + Leucovorin during the first and last week of radiotherapy. Surgery was performed 6-8 weeks after completion of radiotherapy in both groups. Conclusions: Preoperative short-course CRT is an effective and safe modality. It is clinically comparable to long-course CRT in locally advanced rectal cancer.