Anal squamous cell carcinoma: a retrospective case series

Anal cancer is a relatively rare cancer with 660 cases diagnosed in 2000-2015 in Ireland (1). The current standard treatment is radical chemoradiotherapy (CRT). The aim of our study was to review the treatment and outcomes of patients with localised anal squamous cell carcinoma (SCC), who received radical treatment in our radiation oncology network between 2008 and 2014 inclusive.

Data were collected retrospectively from ARIA® oncology information system and patient charts. Statistical analyses were performed using IBM® SPSS® statistical software version 25.0.

Seventy-nine cases of anal SCC were identified. Mean age of patients at commencement of radiotherapy (RT) was 60.2 years (standard deviation: 13.1 years). The most common total RT dose was 50.4 Gy in 28 fractions (N = 58; 73.4%). Median follow-up was 5.6 years. Two (2.6%) patients had persistent disease, seventeen (21.8%) patients developed loco-regional recurrence and nine (11.5%) patients developed solid organ metastases, four of whom had complete treatment response at the primary site. Eight patients underwent salvage anal surgery following completion of RT. Median overall survival was 10.5 years (95% confidence interval (CI) 5.1-15.8 years), median loco-regional relapse-free survival was 10.4 years (95% CI 4.4-16.3 years) and median disease-free survival was 9.3 years (95% CI 6.3-12.2 years).

Our study demonstrates that treatment for anal SCC and outcomes following definitive CRT in Ireland during the study period were comparable to international standards.