Cure Rates According to Dose-Intensity of Chemoradiation in T2N0 Squamous Cell Carcinoma of the Anal Canal

Clin Colorectal Cancer. 2022 Sep;21(3):e226-e231. doi: 10.1016/j.clcc.2022.03.006. Epub 2022 Jun 6.

Abstract

Background: Patients with T2N0 squamous cell carcinoma of the anal canal (SCCA) have comprised less than 30% of patients enrolled in phase III clinical trials of curative-intent definitive chemoradiation. We aimed to evaluate treatment outcomes of these patients according to dose-intensity of chemoradiation.

Materials and methods: Retrospective multicenter study of patients with T2N0 SCCA, with the primary endpoint to compare the progression-free survival (PFS) of patients treated with full definitive chemoradiotherapy (f-CRT, CRT with 2 drugs) versus a nonstandard treatment (NST; radiotherapy only or CRT with 1 drug). Secondary outcomes were rates of complete response (CR), salvage surgery, and colostomy. PFS time was analyzed using the Kaplan-Meier method and differences in survival outcomes were assessed using the log-rank test and adjusted for prognostic covariates using a multivariable Cox regression model RESULTS: From March 2006 to January 2020, 74 patients were included. Most patients (n = 58; 78.4%) received f-CRT. In a median follow up time of 66.1 months, the unadjusted median PFS was 128.3 months (95% confidence interval [CI] 105.5-151.1) for f-CRT versus 74.1 months for NST (95% CI 45.8-102.4; P = .067). CR was achieved by 51 (87.9%) versus 11 (68.9%; P = .065) patients treated with f-CRT or an NST, respectively. Comparing f-CRT versus NST, the colostomy rates were higher for those treated with an NST: 5 (32.8%) versus 5 (9.5%; P = .019) CONCLUSION: For patients with T2N0 SCCA, f-CRT remains the standard treatment, offering higher CR and less likelihood of colostomy.

Keywords: Anal cancer; Chemoradiation; Colostomy; Early-stage; Radiotherapy.

Publication types

  • Multicenter Study

MeSH terms

  • Anal Canal / pathology
  • Anus Neoplasms* / pathology
  • Carcinoma, Squamous Cell*
  • Chemoradiotherapy / methods
  • Humans
  • Retrospective Studies

Supplementary concepts

  • Anal Canal Carcinoma