Pre-cancerous Anal Lesions in Heterosexual and Homosexual HIV Positive Men Receiving or Not Receiving Anti-HIV Therapy

Anal carcinoma is strongly related to infection with high-risk types of human papillomavirus (HPV), as has been seen for cervical, vaginal, vulvar, and penile cancer. The incidence of anal cancer in men who have sex with men (MSM) is estimated to be 35 cases/100,000 person-years.

This incidence is comparable to that observed for cervical cancer before the introduction of routine screening. The rate of anal cancer is twice as high in HIV-positive than in HIV-negative MSM.

Investigators have used anal cytological testing and colposcopy to test for anal intraepithelial neoplasia (AIN), which are pre-cancerous lesions that can progress to invasive cancer.

A high incidence and prevalence of AIN have been reported in HIV-positive and negative MSM. These studies have included predominantly white men and have not included HIV-positive men without a history of sex with men, despite some evidence that these men are also at increased risk for anal cancer.

Moreover, few studies have directly evaluated the effect that antiretroviral therapy (ART) has on either anal HPV infection or AIN. The current study was performed to determine the prevalence of anal HPV infection and AIN in a diverse population of HIV-positive men, including men of color, men with and without a history of sex with other men, and men receiving or not receiving effective ART.

Ninety-two participants--53% Latino, 36% African American, and 40% without a history of receptive anal intercourse (RAI)were evaluated with a behavioral questionnaire, liquid-based anal cytological testing, Hybrid Capture 2 human papillomavirus (HPV) DNA assay and polymerase chain reaction, and anal colposcopy with biopsy of lesions.

Results

High-risk HPV DNA was identified in 61%, and this was associated with a history of RAI (78% vs. 33%; P < .001); 47% had abnormal cytological results, and 40% had AIN on biopsy.

In multivariate analysis, both were associated with a history of RAI and lower nadir CD4⁺ cell counts (P = .06 and P = .01). Current ART use was protective.

Conclusions

Although anal infections with high-risk HPV and AIN in HIV-positive men are associated with a history of RAI, both conditions are commonly identified in HIV-positive men without this history. Both lower nadir CD4⁺ cell counts and lack of current ART were associated with AIN but not with the detection of anal HPV.

Discussion

In this study, investigators demonstrated a high prevalence of AIN and anal HPV in a predominantly Latino and African American group of HIV-positive men.

The questionnaire used in the study, which provides a much more detailed sexual history than would be obtained in clinical practice, did not identify factors that reliably discriminated those at low risk for AIN.

The authors say these data strongly suggest that, if instituting an anal cancer- screening program, all HIV-positive men, regardless of sexual orientation, should be offered participation. Other researchers have made a similar claim to include all HIV-positive women in anal cancer screening programs, regardless of history of RAI.

Infection with high-risk HPV appears to be a necessary factor for having abnormal cytological results or AIN according to histological testing.

The authors conclude, “The present study does not provide direct evidence as to whether screening for AIN is clinically beneficial. An anal cancer screening program should identify patients with high-grade AIN for which there is a surgical intervention, which will reduce the risk of invasive carcinoma.”

Division of International Medicine and Infectious Diseases, Weill Medical College of Cornell University, New YorkPresbyterian Hospital, Division of Infectious Diseases and Department of Pathology, Columbia University College of Physicians and Surgeons, and Medical and Health Research Association of New York City, New York, New York.

10/13/04