RESUMEN
BACKGROUND: Chemoradiotherapy (CRT) with flourouracil and mitomycin is the standard treatment for squamous cell carcinomas of the anus (SCCA), however the associated acute toxicity often hinders compliance. Although weekly cisplatin is a well-established treatment for other squamous cell carcinomas, it has not been explored in SCCA. PURPOSE: To investigate if radiotherapy (RT) with weekly cisplatin is a feasible option for SCCA and to report the acute toxicity. MATERIAL/METHODS: Patients were treated with RT and weekly cisplatin 40 mg/m2 between 1998-2020. Retrospective data from medical records (n=65) and prospectively collected data from an observational study (n=51) comprising physician assessed toxicity (NCI-CTCAE 4.0), patient-reported outcomes (EORTC-QlQC30 + CR29) baseline, mid-therapy, end of treatment and 2-4 weeks post-treatment were included. Disease-free survival (DFS) and overall survival (OS) were estimated using the Kaplan-Meier method. RESULTS: We included 116 patients. T-stages were T1:4%, T2: 71%, T3: 17%, T4: 8% and 47% has N+ disease. RT doses were 53.75-64 Gy/45-51.2 Gy and the mean cumulative dose of cisplatin was 307.5 mg. The median overall treatment time was 43 days. Within 6 months after CRT 88.9 % had complete response. The median follow-up time was 4.5 years and 5-year DFS and OS were 77% (95%CI 68.7;84.5%) and 86.4% (95%CI 78.3;91.7%), respectively. Hospitalization occured in 20% with 2.6% being admitted due to febrile neutropenia. Hematological toxicity was low with 13.7% grade 3 and 3.9% grade 4. Anal pain, skin, gastrointestinal and urogenital toxicity were mild. CONCLUSION: RT and weekly cisplatin for SCCA showed good outcome results and an acceptable acute toxicity profile.