Despite the increasing evidence for chemoradiotherapy as standard treatment for anal cancer in patients with HIV infection, there is still some uncertainty regarding increased toxicity and adverse effects on the immune status.

We report the clinical outcome of 5-fluorouracil/mitomycin C-based concurrent chemoradiotherapy for anal carcinoma in patients with HIV infection with an emphasis on the long-term course of CD4 counts and the HIV-related morbidity during follow-up.

A retrospective single-institution chart review was performed.

Between 1997 and 2012, 36 HIV-positive patients were treated with standard chemoradiotherapy (median tumor dose, 54 (range, 50.4-60.4) Gy at 1.8 Gy/fraction; 5-fluorouracil, 800-1000 mg/m(2), days 1-4 or 1-5; mitomycin C, 10 mg/m(2), day 1, in the first and fifth week).

A retrospective analysis was performed with respect to tumor response, local control, cancer and overall survival, and toxicity. Immunological parameters, including pre- and posttreatment CD4 counts, viral load, and HIV-specific morbidity were recorded during follow-up.

Chemoradiotherapy could be completed in all patients. Acute grade 3 toxicities occurred in 17/36 patients (47%). Complete response was achieved in 31 patients (86%). Five-year local control, colostomy-free, cancer-specific, and overall survival were 72%, 87%, 77%, and 74%. The median pretreatment CD4 count significantly decreased from 367 cells/μL to 139 cells/μL, 3 to 7 weeks after completion of chemoradiotherapy (p < 0.001). Four patients (11%) experienced opportunistic illnesses during the follow-up (median, 66; range, 10-164 months).

This study is limited by its retrospective design and its small sample size.

Our data confirm again that, in the highly active antiretroviral therapy era, anal cancer can be treated in HIV-positive patients with standard chemoradiotherapy, with a clinical outcome similar to their HIV-negative counterparts. The chemoradiotherapy-related decline of the CD4 counts, which remain decreased up to 6 years after chemoradiotherapy, was not associated with increased HIV-related clinical morbidity.