Chemoradiotherapy versus radiotherapy alone in the management of early-stage anal squamous cell carcinoma: A comparative analysis of the French cohort FFCD-ANABASE

Abstract

IntroductionEarly-stage anal squamous cell carcinomas (ASCC) are usually treated with chemoradiotherapy (CRT), with good outcomes. Radiotherapy (RT) alone might be sufficient while reducing toxicity. MethodsPatients included in the French prospective FFCD-ANABASE and treated for T1–2N0 ASCC between 2015/01 and 2020/04 were divided into CRT and RT groups. Clinical outcomes and toxicity were reported. Propensity score matching was conducted for 105 pairs of patients. Results440 patients were analyzed: 261 (59.3 %) in the CRT group and 179 (40.7 %) in the RT group. The median follow-up was 35.7 months. Patients receiving CRT were younger, had better Performance Status (PS) and larger tumors. No statistical difference was observed for 3-year Disease-free survival (85.3 % vs 83 %, p = 0.28), Overall survival (89.6 % vs 94.8 %, p = 0.69) and Colostomy-free survival (84.5 % vs 87.2 %, p = 0.84) between CRT and RT groups, respectively. Propensity score-matched analysis confirmed these findings. Treatment interruptions were significantly more frequent in the CRT group (36.3 % vs 21.9 %, p = 0.0013), resulting in an Overall Treatment Time (OTT) extended by 7 days. Grade 3 CTCAE v4.0 toxicities were more prevalent in the CRT group (46 % vs 19 %, p < 0.001). ConclusionAdding chemotherapy to radiotherapy did not significantly improve outcomes for T1–2N0 ASCC in our study, but increased toxicity and OTT.