Comparison of 5-FU vs capecitabine in combination with mitomycin or cisplatin in the treatment of anal cancer.

Abstract

3576 Background: The patterns of capecitabine use as an alternative form of fluoropyrimidine to infusional 5-FU in the non-operative management of anal cancer in the real world are poorly described. Our objectives were to determine the frequency of capecitabine use, compare the observed outcomes between oral and intravenous fluoropyrimidines, and examine for variations in treatment-related adverse events between the two agents. Methods: All anal cancer patients who received either capecitabine or infusional 5-FU as part of their chemoradiation treatment from 2004 to 2013 at any 1 of 6 cancer centers in British Columbia were included. Chi-square and Wilcoxon-Mann tests were used to assess for associations between treatment groups and clinical characteristics and outcomes. Results: A total of 486 patients were identified: median age was 59 (IQR 53-67) years, 175 (36%) were men, 418 (86%) had ECOG 0/1, and 30 (6%) were HIV positive. Median total radiation dose was 54 cGy (IQR 50-54) and 47 (10%) underwent a colostomy prior to chemoradiation. Baseline characteristics were balanced between the two groups with respect to age, gender, ECOG, and HIV status (all p > 0.05). Prior to 2010, only 5-FU was utilized. From 2010 to 2013, 155 and 82 patients (65% vs 35%) received capecitabine vs 5-FU, respectively. Overall (68% vs 67%, p = 0.831) and disease-free survival rates (59% vs 59%, p = 0.926) at 3 years were similar in the capecitabine vs 5-FU groups. Rates of subsequent abdomino-perineal resection were also similar (10% vs 14%, p = 0.164). Patients who received 5-FU were more likely to report adverse effects (76% vs 57%, p < 0.01). The capecitabine group had a lower incidence of stomatitis (7% vs 43%, p < 0.01) whereas the 5-FU cohort reported less frequent hand-foot syndrome (1% vs 7%, p < 0.01). The rates of myelosuppression, nausea/vomiting, diarrhea, and rash were similar between the two groups (all p > 0.05). Conclusions: This represents one of the largest population-based studies to demonstrate a preference for capecitabine in place of 5-FU in the management of anal cancer. Survival outcomes were similar between the two treatment groups, but capecitabine may be better tolerated in the real world.