A Smarter Screening Strategy for Prostate Cancer Can Predict Mortality

Prostate cancer screening that relies on the prostate-specific antigen (PSA) test has survived significant controversy. A collaborative effort by urologists and public health specialists from various healthcare systems around the country has found that PSA levels measured in midlife (45 to 59 years of age) are a strong predictor of future lethal prostate cancer.

In 2012, the US Preventive Services Task Force (USPSTF) gave the PSA test a D rating, citing the harms from the test outweighed benefits. The panel of experts that came up with the recommendation were concerned about potential overtreatment of patients, which could result in harm, rather than good. Urologists were concerned that this recommendation would results in a drop-off in screening rates, and 2 years later, the National Comprehensive Cancer Network (NCCN) released its own guidelines at NCCN’s annual meeting. These guidelines recommended a single test at age 45 to 50 years, and subsequent screening was recommended based on an assessment of the individual’s risk factors.

The present study, published in the Journal of Clinical Oncology, seems an extension of the NCCN guidelines. The authors used data from the Physicians’ Health Study (PHS), a randomized, placebo-controlled trial that tested aspirin and risk of cardiovascular outcomes, and was initiated in 1982. Blood samples from 234 men, who were between 40 and 59 years of age, who participated in the study had been analyzed for their baseline PSA levels. The study also analyzed samples from 711 age-matched controls. Of these, 71 patients who developed prostate cancer were rematched with 213 controls.

The study found that the median PSA among controls was 0.68, 0.88, and 0.96 ng/mL for men age 40 to 49, 50 to 54, and 55 to 59 years, respectively. The risk of lethal prostate cancer was strongly associated with the following median baseline PSA in midlife:

• 8.7 at 40 to 49 years
• 12.6 at 50 to 54 years
• 6.9 at 55 to 59 years.

“We found a single baseline PSA-level measurement during midlife could accurately predict future risk of lethal prostate cancer,” according to author Mark Preston, MD, MPH. “These data identify subgroups of men, based on their PSA levels at a given age, who could benefit from screening intervals tailored to their actual magnitude of risk.”

Reference

Preston MA, Batista JL, Wilson KM, et al. Baseline prostate-specific antigen levels in midlife predict lethal prostate cancer [published online June 14, 2016]. J Clin Oncol. doi:10.1200/JCO.2016.66.7527.