Replacing 5-fluorouracil by capecitabine in localised squamous cell carcinoma of the anal canal: systematic review and meta-analysis

BACKGROUND The standard treatment for localised squamous cell carcinoma of the anal canal (SCCAC) is chemoradiotherapy (CRT) with infusional 5-fluorouracil (5-FU) and mitomycin. Because 5-FU and capecitabine have offered similar efficacy in many phase-III trials of solid tumours, studies have tested capecitabine in this setting of SCCAC. However, these studies are small and have reported variable results. Therefore, a systematic review and meta-analysis was performed. METHODS Medline, Scopus and Embase were searched for studies that evaluated the efficacy outcomes of capecitabine used as a substitute of 5-FU in the CRT of localised SCCAC. The primary endpoint was complete response rate (CRR) at 6 months. Metaprop analysis of reported CRR-based on pooled estimates of proportions with corresponding 95% confidence intervals (95%CI) were calculated on the base of the Freeman-Tukey double arcsine transformation. RESULTS We retrieved 300 studies, of which six met our eligibility criteria. The capecitabine dose ranged from 500 mg/m2 to 825 mg/m2 BID for 5 days per week during radiation. With a total of 218 patients, the median follow-up was 21.5 months (14-23). The pooled analysis of three trials (N = 132 patients) reported a CRR at 6 months of 88% (83%-94%), considering all clinical stages. The pooled analysis of overall CRR (N = 218 patients), evaluated at different intervals, showed an overall CRR of 91% (87%-95%). Rates of locoregional relapse varied from 3.2% to 21%. The majority of patients completed the planned radiotherapy dose (93.5%-100%) and any chemotherapy interruption was reported in up to 55.8% of patients. CONCLUSIONS Capecitabine is an acceptable and more convenient alternative to infusional 5-FU in the CRT for localised SCCAC, offering similar clinical CRR to those reported by phase-III trials.