The prevalence of squamous-cell carcinoma of the anus seems to be increasing in HIV positive patients. Clinical features and prognosis in this population have not been well evaluated.

To assess the prognosis of anal squamous-cell carcinoma in HIV positive patients as well as clinical features and treatment procedures.

A series of 20 HIV positive patients presenting with invasive anal squamous-cell carcinoma was retrospectively analyzed. Data have been compared to those obtained from 24 randomly selected HIV negative patients who were followed during the same periods in the same centers for anal carcinoma with similar histopathological features.

The follow-up ranged from 10 to 172 months. No difference was observed between the two groups concerning the clinical features leading to anal cancer diagnosis, although HIV positive patients were younger. Anal cancer was more frequently associated with lymph node metastasis in HIV positive (60 %) than in HIV negative (17 %) patients, although its size was similar in both groups. Radiotherapy was similarly performed in both groups, while chemotherapy was administered less frequently in HIV positive than in HIV negative patients (54 % vs 25 %). Immediate side effects and mortality at 1 year follow-up were similar in both groups, whereas the objective initial response to therapy (50 % versus 88 %), the remission rate with anal conservation at 1 year follow-up (45 % versus 88 %), and the mortality at 3 years were better in HIV negative patients.

The prognosis of anal squamous-cell carcinoma is poor in HIV positive patients. This correlates with a more advanced tumor stage and an alteration of systemic immunity status at the time of diagnosis and less response rate to treatment. Detection of precancerous lesions and treatment procedures should be evaluated in HIV infected patients.