536P - Docetaxel, cisplatin, and 5-fluorouracil (DCF) chemotherapy in the treatment of metastatic or unresectable locally recurrent anal squamous cell carcinoma: A phase II study of French interdisciplinary GERCOR and FFCD Groups (Epitopes-HPV02 study)

Abstract

Background: Anal Squamous Cell Carcinoma (ASCC) is a rare disease, but its incidence is markedly increasing. To date, in advanced ASCC, no standard regimen exists. We have previously published the potential role of DCF regimen. Among 8 advanced ASCC consecutive patients who relapsed after CRT, the DCF regimen induced a complete response in 4 patients, including 3 pathological complete responses. Thus, this study was designed to confirm the interest of DCF regimen in advanced ASCC patients. Methods: A multicentre phase II trial was conducted among 25 hospitals in France. Main eligibility criteria were histologically proved unresectable locally advanced recurrent or metastatic ASCC, ECOG-PS <2, and being eligible for DCF. Patients received either 6 cycles of standard DCF or 8 cycles of modified DCF depending on age (> vs. < = 75 years-old) and ECOG-PS (0 vs. 1). The trial was set up based on a Simon’s optimal two-stage design, allowing an early futility interim analysis amid the first 21 patients. The primary endpoint was the observed PFS rate at 12months from the first DCF cycle. A PFS rate above 25% was expected. With a unilateral alpha error of 5% and a statistical power of 90%, 66 evaluable patients had to be included. Results: 66 patients were enrolled from September 2014 to January 2017. Median age was 60.05 years (range, 38-78) with female predominance (81.8%). 40 (60.6%) patients had locoregional involvement at enrolment, and the most frequent metastatic sites were liver (60.6%), distal lymph node (48.5%), and lung (36.4%). At interim analysis, 10 (47.6%) patients were progression-free at 12 months from the first DCF cycle. To date, 65 patients are assessable for response rate by investigators. The objective response rate is 87.7%, including 36.9% of complete responses. Among the first 32 patients with ≥12 months of follow-up, 15 (46.9%) patients were progression-free at 12 months. Conclusions: This first ever conducted prospective trial in front-line advanced ASCC demonstrated a high long-lasting response rate of the DCF regimen. DCF regimen should then be considered as a standard of care in this situation. Clinical trial identification: NCT02402842 Legal entity responsible for the study: University Hospital of Besancon Funding: Research grant from the University Hospital of Besançon Disclosure: All authors have declared no conflicts of interest.