He said that men with PSA below the median of 0.6ng/ml should have a further PSA test at age 52 and, if still below the median, again at age 60. The research was based upon the Malmö Preventive Medicine (MPP) study, a cardiovascular prevention project that enrolled Swedish men aged <50 between 1974-1986. A sub-group of men had repeat blood samples 6 years later. These investigators previously reported that men with PSA below the median at age 44-50 have a low risk of subsequent advanced prostate cancer, and men with PSA below the median at age 60 can be exempted from further screening. They build upon this work and herein investigate alternative screening strategies for men with a low PSA at their first test. They sought to strike a balance between maximizing early detection of aggressive cancer while reducing unnecessary screening. Patients with metastases at diagnosis were identified via the Swedish Cancer Registry, with those developing metastases after diagnosis identified by chart review. They calculated the number of metastasis events avoidable by different screening strategies using the conservative assumption that a cancer becomes incurable 10 years before metastasis.
In the cohort of 4,230 MPP-participants providing an evaluable second blood sample, 94 were diagnosed with metastasis through 2006. PSA was strongly predictive of subsequent risk of metastasis (C-index of 0.71 and 0.76 at age 45 and 52). For every 10,000 men with a PSA <0.6ng/ml at 45, 65 would be diagnosed with metastases within 25 years, suggesting that a second screen at age 60 may come too late. Of these 65 men, 28 would be detected and curable if offered an intermediate screen at age 52. Men with PSA in the lowest quartile with a PSA<0.4 were similarly at insufficiently low risk (58 per 10,000 subsequently developed metastasis) to rule out subsequent screening.
Presented by Hans Lilja, et al. at the American Urological Association (AUA) Annual Meeting - May 14 - 19, 2011 - Walter E. Washington Convention Center, Washington, DC USA
Reported for UroToday by Christopher P. Evans, MD, FACS, Professor and Chairman, Department of Urology, University of California, Davis, School of Medicine.