A randomized controlled pilot study to compare capecitabine-oxaliplatin with 5-FU-leucovorin as neoadjuvant concurrent chemoradiation in locally advanced adenocarcinoma of rectum

Context: Established as an adjuvant chemotherapy, CapeOX has recently been shown to have radiosensitizer property in a phase I and II studies, with appreciable downstaging and tolerable toxicities. Aims: The study was designed to evaluate whether the capecitabine-oxaliplatin combination was superior to 5-fluorouracil (5-FU)-leucovorin as radiosensitizer for neoadjuvant chemoradiation in downstaging locally advanced rectal adenocarcinoma and to compare the toxicities between the two arms. Settings and Design: Single institutional, double blinded, prospective, noncrossover, randomized control pilot study. Subjects and Methods: In arm A (n = 21), patients received capecitabine (1,000 mg/m(2)daily) in twice dailydoseon days 1-14 and 25-38 and oxaliplatin (85mg/m(2)) intravenous (IV) over 2 h, on D1 and D29. In arm B (n = 21), patients received leucovorin (20mg/m(2)) and 5-FU (350mg/m(2)) from D1-5 and D29-33. Patient in both the arms received concurrent radiation (50.4 Gy in 28 #, in conventional fractionation of 1.8 Gy per fraction). Six to eight weeks after concurrent chemoradiation, patients underwent assessment and surgery with total mesorectal resection. Postoperatively, adjuvant chemotherapy with m-FOLFOX 6 of 4 months was given to all patients. Statistical Analysis Used: Chi-square test was used to compare categorical variables between the groups. Results: Objective response rate (ORR) in arm A was 80.95% compared to arm B which had 66.66% (P = 0.3055). Pathological complete response (pCR) rate of arm A was comparable to arm B (23.8vs 14.28%, P value = 0.6944). Surgery with R0 resection was possible in 80.95% cases of arm A compared to 66.66% cases of arm B (P = 0.4827). Grade III toxicities were quite comparable between two treatment arms. Conclusions: In terms of ORR, pCR rate, R0 resection, and toxicity profile; both the arms were comparable.