Postoperative versus definitive chemoradiation in early-stage anal cancer. Results of a matched-pair analysis

The goal of the present study was to comparatively assess the results of definitive chemoradiation (CRT) with or without previous macroscopically complete resection in patients with early-stage node-negative (T1-2 N0) anal carcinoma.

A total of 20 patients with T1-2 N0 anal carcinoma who received radiotherapy (RT) with or without chemotherapy following incidental R0/1 tumor resection (S/CRT group) were selected. These were matched to 20 comparable patients who underwent definitive chemoradiation without previous surgery (CRT group). Major objectives of this analysis were treatment outcomes in terms of locoregional tumor control (LRC), overall survival (OS), colostomy-free survival, and toxicity.

Patients treated postoperatively received significantly lower RT doses (median 54.0 Gy vs. 59.7 Gy; p < 0.001) and less frequently concomitant chemotherapy than those treated definitely. The 5-year LRC and 5-year OS rates were 97.5% and 90.0%, respectively, without significant differences between the S/CRT and the CRT groups. The distribution of acute and late toxicities was comparable, and the 5-year colostomy-free survival was 95% in both groups.

This matched-pair comparison of incidental R0/1 resection plus dose-reduced CRT with standard definitive CRT of early-stage anal cancer shows similar treatment results. Thus, dose-reduced RT with or without chemotherapy may be considered in R0/1 resected patients with T1-2 N0 anal carcinoma.