Background: There are no randomized phase III trials comparing 5-fluorouracil/mitomycin (FM) versus capecitabine/mitomycin (CM) in combination with radiotherapy (RT) for locally advanced anal cancer. We aim to evaluate the outcomes of patients treated with FM and CM at our institution.
Methods: Patients with stage I-III anal cancer who initiated curative-intent RT (50-54 Gy) with either CM or FM between 1998 and 2013 at the BC Cancer Agency were reviewed. Cox proportional models were used to analyze the impact of regimen on disease-free survival (DFS) and anal cancer-specific survival (ACSS).
Results: A total of 300 patients were included. Baseline characteristics were well-distributed between the groups. A total of 194 patients (64.6%) received FM and 106 (35.3%) CM. The 2-year DFS was 79.7% for CM [95% confidence intervals (95% CI), 71.1-88.3%] and 78.8% for FM (95% CI, 73-84.6%); 2-year ACSS was 88.7% for CM (95% CI, 81.8-95.5%) and 87.5% for FM (95% CI, 82.8-92.2%). On multivariate analysis, only HIV status, clinical T size (≤5 vs. >5 cm), and N status (negative vs. positive) remained as significant prognostic factors for both DFS and ACSS. Chemotherapy regimen (CM vs. FM) had no impact on either DFS [P=0.995; hazard ratios (HR) =0.99; 95% CI, 0.57-1.74] or ACSS (P=0.847; HR =0.93; 95% CI, 0.46-1.86).
Conclusions: In our population-based study, CM and FM concomitant with RT achieved similar DFS and ACSS. Substitution of capecitabine for infusional 5-FU may therefore be a reasonable option for patients and physicians who prefer to avoid the inconvenience and potential complications of a central infusional device.
Keywords: 5-fluorouracil (5-FU); Anal cancer; capecitabine.