A prospective randomized trial comparing capecitabine-based chemoradiotherapy with 5-FU-based chemoradiotherapy in neoadjuvant setting in locally advanced carcinoma rectum.

Abstract

Fluorouracil (FU)based chemoradiotherapy is regarded as a standard perioperative treatment in locally advanced rectal cancer. Capecitabine is an oral fluoropyrimidine that generates 5FU preferentially at the tumor site by exploiting the higher activity of the enzyme thymidine phosphorylase in tumor tissue compared with healthy tissue. As an oral agent, capecitabine can be administered in the outpatient setting, potentially providing FU exposure similar to a lowdose continuous infusion of 5FU. To compare capecitabine with 5FU, with regard to efficacy and toxicity when used in neoadjuvant setting along with radiotherapy for locally advanced carcinoma rectum. Thirty patients were enrolled, 14 in 5FU and 16 in capecitabine arm. All patients were planned for 45 Gy/25#/5 weeks pelvic radiotherapy followed by a boost of 5.4 Gy/3#/3 days. 5FU was prescribed at a dose of 500 mg/m2 #1-#5 and #21-#25 of RT and capecitabine was given at 1650 mg/m2 on RT days throughout the course of radiotherapy. A magnetic resonance imaging/computerized tomography scan was done at the start of treatment and 1 month after completion of treatment, followed by surgery. Toxicity was assessed weekly during treatment and on the first followup. Response rates and toxicity profile of capecitabinebased cathode ray tube (CRT) was similar to 5FUbased CRT with nonsignificant P values. Capecitabine may be used as an alternative in patients who do not tolerate 5FU.