Carcinoma of the conjunctiva and HIV infection in Uganda and Malawi

Abstract

Aim: To investigate the association of human immunodeficiency virus (HIV) infection and carcinoma of the conjunctiva in Africa, and the role of human papilloma virus type 16 (HPV-16).

Methods: Patients in Uganda and Malawi presenting to eye clinics with lesions suspicious of carcinoma were studied. Pathological confirmation of eye lesions was sought. HIV testing of patients who were biopsied and, in Uganda, of matched case control subjects was carried out as was testing of a sample of fixed biopsies for HPV-16 by polymerase chain reaction (PCR). The HIV-1 serology, histopathology of conjunctival biopsies (conjunctival intraepithelial neoplasia (CIN), invasive carcinoma, other lesions), and prevalence of HPV-16 infection were determined.

Results: Of Ugandan patients, 27/38 (71%) with carcinoma (27 invasive carcinoma, 11, CIN) were HIV positive compared with 12/76 (16%) of controls (odds ratio 13, 95% confidence interval 5-38). The calculated population aetiological fraction of carcinoma associated with HIV was 66%. Of 32 Malawian patients (20 invasive carcinoma, 12 CIN), 25/29 tested (86%) were HIV positive. HPV-16 infection was found in 7/20 (35%) of carcinoma samples, 0/9 pingueculae, and 2/6 conjunctivitis samples.

Conclusions: HIV infection is strongly associated with an apparent increase in the incidence of conjunctival carcinoma in Africa. While ultraviolet light is probably the prime risk factor and HPV-16 is implicated in a proportion of cases, the interactions of ultraviolet light, HIV, HPVs, and other factors are unclear in the pathogenesis of carcinoma. The disease represents another model of multifactorial epithelial carcinogenesis.

PIP: During January-December 1994 at seven countrywide eye clinics and during September-October 1994 at New Mulago Hospital in Kampala, Uganda, biopsies were taken of suspicious conjunctival lesions and blood samples were drawn for HIV testing from all patients presenting. During October 1993 to March 1994 at the eye department of Queen Elizabeth Central Hospital in Malawi, biopsies were taken of suspicious conjunctival lesions from all patients. 38 patients in Uganda and 32 patients in Malawi had carcinoma of the conjunctiva. HIV-infected patients in Uganda were more likely to have carcinoma of the conjunctiva than HIV-negative patients (71.1% vs. 15.8%; odds ratio [OR] = 13.1). 2 of the 27 HIV-positive cases in Uganda had AIDS. The population etiological fraction of carcinoma associated with HIV infection stood at 66% for the Ugandan population. 86% of the tested Malawian patients (78.1% of all Malawian patients) had HIV infection. Almost 50% of HIV-infected Malawians had AIDS. Human papillomavirus-16 (HPV-16) was detected in 35% of invasive carcinoma cases but not in pingueculae and inflamed conjunctiva lesion cases. The researchers hypothesized that ultraviolet light, HIV, HPV-16, and other agents contribute to a complex carcinogenic process.