Anal squamous cell carcinoma in KwaZulu-Natal Province, South Africa, with special reference to the influence of HIV infection on clinical presentation and management outcome

Background. Anal carcinoma is rare. Clinicopathological features influencing outcome have not been determined in HIV-negative and HIV-positive patients in South Africa. Objectives. To compare presentation and treatment tolerance among HIV-positive and negative patients. Methods. This study was a retrospective analysis of prospectively collected data on patients with squamous cell carcinoma of the anus. Patients with known HIV status were extracted from the anal cancer database and analysed. Data analysed included demographics, clinical features, stage, pathology and treatment outcome. Results. There were 268 patients with anal squamous cell carcinoma (n=135 HIV-positive and n=33 negative). The median age was 39 years and 53 years for HIV-positive and negative patients, respectively, the male/female ratio was 1:2.7 and 1:1.8 for the two groups, and the ratio of anal margin to canal distribution was 1.3:1 and 1:1. Disease stage was similar, with minor differences. The resection rate was 17% in HIV-positive patients and 9% in those who were HIV-negative. Half the patients in both groups were eligible for definitive therapy, and side-effects of oncotherapy occurred with similar frequency in both groups. The recurrence rate was 7% in both groups and the disease-free interval was similar. Overall survival was longer for HIV-negative patients (p=0.0240). Conclusions. The prevalence of anal squamous cell carcinoma is much higher in individuals with HIV infection than in those who are HIV-negative. HIV-positive patients present at a younger age and with locally advanced disease that responds less well to standard treatment, and their survival is poorer.