February 11, 2009
In a poster presentation at CROI 2009 in Montreal, Canada, there's more sobering news on a serious HPV-related condition in men who have sex with men (MSM) that can lead to anal cancer. Unlike other diseases that have declined in incidence since the advent of HAART, such as CMV or KS, the appearance of this condition (caused by the human papillomavirus, or HPV) has continued to increase since the beginning of HAART. Incidence of anal cancer is 59-times higher among MSM and nearly 7-times higher in HIV-positive women. This reiterates and underscores the rise of cancers with infectious causes among people living with HIV.
Project Inform has reported on this condition from both the 2008 International Conference and 2008 ICAAC, and this California study by University of California at San Francisco (UCSF) and Stanford University continues to document data on the direct progression of HGAIN to anal cancer. HGAIN, or high-grade anal intraepithelial neoplasia, is a condition where surface skin cells of the anus show high-grade abnormalities which can directly develop into cancer. Medical records of UCSF patients who developed anal cancer from 1997 to 2007 were reviewed to check whether anal cancer had developed in the same place as cases of HGAIN. From a total caseload of 1,700 HIV-positive MSM, 65 cancers had been diagnosed, and 27 of them had enough documentation of the HGAIN/anal cancer relationship to inform this study.
Of those who progressed to anal cancer, the average age was about 50 (range 39-69) and average CD4 count was 241 (range 49-1,000). Prevalent HGAIN was first diagnosed on average about 4 years (range 4-139 months) before developing cancer. Although these averages may be useful guides, there's a wide range of ages and CD4 counts at which HGAIN and cancer were detected. Cancer was also diagnosed at a younger average age in HIV-positive MSM than for the general population.
Of particular importance are the data that show that more than half of the 27 (15) did not present with symptoms. Their cancers were detected through routine check-ups with their doctors. The procedures included digital rectal exams (DRE), of which 27 men showed an obvious abnormality, and high-resolution anoscopy (HRA), of which 3 men were solely detected for cancer.
Similar to high-grade cervical neoplasia and cancer, treating HGAIN with the established standard of care for cervical neoplasia could go far to help prevent men and women from developing anal cancer. However, more concrete data showing the relationship and progression from HGAIN to anal cancer is sadly absent.
So, given the paucity of this data linking HGAIN to anal cancer and the absence of the standards of care for screening and treating anal neoplasia and cancer, it's wise for people living with HIV to bridge these health conversations with their providers. Both men and women can discuss what's needed in order to screen for resolving these conditions before they advance to cancer.
The researchers stated that carefully controlled studies are needed to further evaluate the screening and treatment of HGAIN in HIV-positive MSM to prevent anal cancer. A great resource for information about these conditions is the website for the UCSF Anal Neoplasia Study.