Colorectal cancer in HIV positive individuals: the immunological effects of treatment

Abstract

Background and objectives: Since the introduction of highly active antiretroviral therapy (HAART), non-AIDS defining malignancies including colorectal cancer (CRC) have emerged as major health concerns for people living with HIV.

Methods: From a prospective database of 11,112 HIV seropositive individuals, we identified 11 patients with CRC. Clinicopathological details on the presentation, treatment and outcomes were collected.

Results: All were male with a median age of 50 years (range 36-67) and median duration of HIV infection of 7.2 years (range 0-21). Five had metastatic disease at presentation, including 1 patient with a small cell cancer of the rectum. Patients were treated along conventional lines for CRC with concomitant HAART and opportunistic infection prophylaxis. During treatment, median CD4 cell counts fell from 357/mm(3) at CRC diagnosis to 199/mm(3), although no opportunistic infections were recorded. Three patients have died and the 5-year overall survival measured 65% (95% confidence interval 32-98%).

Conclusions: Treatment for CRC reduces cellular immunity and potentially puts HIV patients at risk of opportunistic infections; knowledge of HIV status prior to starting treatment is essential. This risk may be reduced by concomitant HAART and prophylaxis. Clinicians managing CRC should consider screening patients for HIV before starting chemotherapy or radiotherapy.