Frequent PSA screening, lower prostate cancer incidence, in veterans with HIV
Conference on Retroviruses and Opportunistic Infections (CROI), March 4-7, 2019, Seattle

 

Mark Mascolini

 

Prostate-specific antigen (PSA) testing proved common in HIV-positive US veterans, even in those with poor overall prognosis by CD4 count and VACS Index [1]. But veterans with HIV got their PSA measured significantly less often than veterans without HIV across 3 study periods. The same analysis found lower prostate cancer incidence in veterans with HIV than in matched HIV-negative counterparts.

 

Researchers working with the Veterans Aging Cohort Study (VACS), a national cohort of veterans with or without HIV, noted that non-AIDS cancers have emerged as frequent complications in aging HIV populations. Prostate cancer ranks as a leading malignancy in the general population, but its impact in HIV infection remains unclear.

 

To address that issue, a VACS team tracked prostate cancer screening, incidence (new diagnoses), and disease characteristics in their large US veterans cohort. They focused on 36,333 veterans with HIV and 83,003 without HIV at least 45 years old. Using procedure and lab codes, they determined rates of PSA testing and prostate biopsy. They used a VA cancer registry to calculate new diagnoses of prostate cancer. These analyses excluded men with a history of prostate cancer, abnormal PSA or digital rectal exam, benign prostatic hyperplasia, lower urinary tract symptoms, unexplained weight loss, or back pain.

 

The HIV-positive and -negative groups both averaged a little over 50 years in age, about 48% of both groups were black, and about 40% white. Median follow-up reached 14.5 years in the HIV group and 15.35 years in the non-HIV group. Almost all men with HIV (99%) took antiretroviral therapy, their viral load averaged 21,072 copies and their CD4 count 348. Median VACS Index, which accurately predicts mortality in people with HIV, was more than twice higher (worse) in the HIV group than in HIV-negative controls (29 versus 12, P < 0.001).

 

More than 85% of veterans in all VACS Index prognostic categories got their PSA tested. Among veterans with HIV, PSA testing proved significantly less frequent in those in the worst VACS Index quartile and those with a CD4 count below 200 (P < 0.001 for both).

 

Adjusted incidence of PSA testing lay significantly lower in veterans with HIV (incidence rates ratios [IRR] 0.88 to 0.95 versus HIV-negative veterans in three study periods, 2000-2005, 2006-2010, 2011-2015; P < 0.001 in all three periods). Among men who had a PSA test, subsequent prostate biopsy was similar in those with and without HIV.

 

Clinicians diagnosed prostate cancer significantly less often in veterans with than without HIV (IRR 0.86, 95% confidence interval 0.77 to 0.91, P < 0.001), even after researchers limited the analysis to men who had a PSA test (IRR 0.91, 95% confidence interval 0.84 to 0.98, P = 0.01). Among veterans with prostate cancer, further analysis suggested higher (worse) Gleason grade (P = 0.10) and distant disease (P = 0.09) in men with HIV.

 

VACS investigators concluded that "PSA testing is very common in people with HIV at the Veterans Health Administration, even in those with poor prognosis as measured by CD4 count and VACS Index." And new prostate cancer arose significantly less often in veterans with than without HIV.

 

Reference

1. Leapman MS, Park LS, Stone K, et al. Prostate cancer screening and incidence in aging veterans with HIV. Conference on Retroviruses and Opportunistic Infections (CROI). March 4-7, 2019. Seattle. Abstract 1072.