Definitive chemoradiotherapy for squamous cell carcinoma of the anal canal (SCCAC) with cisplatin and capecitabine: A prospective cohort—preliminary results.

Abstract

e15506 Background: SCCAC is a rare disease. The standard care treatment with curative intent is chemoradiation with mitomycin (MMC) or cisplatin (CDDP) plus infusional 5-FU. Capecitabine may replace 5-FU in MMC doublet. However, MMC and infusional pumps are unavailable in many underdeveloped countries, and there is a lack of prospective data regarding the feasibility and safety of capecitabine combined with CDDP in definitive chemoradiotherapy. Methods: A Prospective cohort study aimed to evaluate the safety and efficacy of treatment with chemoradiation with CDDP60mg/m2 D1 and D29 plus capecitabine 825mg/m2/day BID in a population without MMC and infusional pump access. Eligible pts had T2-4/N0-3/M0 disease and were candidates to full curative CRT. Toxicity evaluation was the primary endpoint, secondary endpoint was response by RECIST v.1.1 at 8 weeks(w) and 6 months(m). The study data were prospectively collected using REDCap. Results: 23 pts were enrolled from Aug/2019 to Oct/2020 with a median follow-up of 7m. Median age 59 years; 76% (n=16) were stage III, 48% (n=11) were ECOG1, and 15% (n=3) were HIV+. All pts received concomitant radiotherapy, MVAT, with a median dose 54Gy in the primary tumor and 45Gy in elective nodes. At 8w, 18 patients were evaluable for response, 56% (n=10) had complete response (CR),39% (n=7) had partial response (PR) and 5% (n=1) progressive disease (PD). At 6 months 11 patients were evaluable for response, 64%(n=7) had CR, 18% (n=2) PR and 18% (n=2) PD. Any grade 3/4 toxicity was present in six pts, four of them radiodermatitis. The most frequent grade toxicities were nausea and radiodermatitis in all pts, anemia 81% (n=17), diarrhea 62% (n=13). Two older pts had definitive suspension of treatment due to toxicity. Three pts had hospitalization because of a skin infection. Six pts had disease recurrence, and two died by the cutoff date. One death related to diarrhea and vomiting toxicity in an older 84-year pt. OS and PFS are not reached. Conclusions: Definitive chemoradiotherapy with cisplatin and capecitabine is feasible; however, the older population is more vulnerable to treatment complications. Further prospective studies with a higher number of patients and longer follow up are required to evaluate SLP and OS.