Difference in toxicity between HIV-positive and HIV-negative patients with squamous-cell cancer of the anal canal treated with concomitant radio-chemotherapy.

Background: The incidence of squamous cell carcinoma of the anal canal has been increasing over the last 30 years. HIV has been found to be a risk factor for the development of this disease; radio-chemotherapy (RTCT) may also be more toxic than in HIV-negative patients. The study aims at assessing whether there are any differences in terms of toxicity between HIV-positive and HIV-negative patients treated with concomitant RTCT.

Methods: Search in MEDLINE, EMBASE, CENTRAL (via Cochrane Library-Wiley), DARE, LILACS bibliographic databases. Experimental and analytical observational studies with at least two comparative arms were included: squamous-cell (SC) anal-canal cancer (ACC) treated with RTCT in HIV-positive HIV-negative patients.

Results: Fifteen publications, 14 retrospective studies and 1 systematic review, were found. All radiotherapy (RT) techniques and all chemotherapeutic agents used to manage this disease were included. No differences were found in terms of duration (P=0.67) and dose (P=0.53) of RT, while CT results were contradictory. Acute and hematological toxicities were significantly higher in HIV-positive patients, while gastrointestinal, dermatological and chronic toxicities did not significantly differ between the two groups. Given the high heterogeneity of the studies, no objective comparison could be made between studies that included antiretrovirals and those that did not.

Conclusions: HIV-positive patients may be at higher risk for acute and hematological toxicity than HIV-negative patients. A precise conclusion cannot be drawn on the use of antiretrovirals, given the high heterogeneity of data.