Re: An Empirical Evaluation of Guidelines on Prostate-Specific Antigen Velocity in Prostate Cancer Detection

Extract

Vickers et al. ( 1 ) reported that prostate-specific antigen velocity (PSAV) was associated with a 5.2-fold increased risk of prostate cancer on biopsy, adjusting for age, PSA, family history, digital rectal examination, and prior biopsy. However, it led to only a modest improvement in area under the receiver operating characteristic curve, leading the authors to conclude that PSAV does not add “important” predictive value.

Numerous aspects of the study design limit the applicability of these results. Contrary to the authors’ suggestion that the Prostate Cancer Prevention Trial (PCPT) represents the “ideal population,” prior studies have shown that PSAV has the best performance characteristics at a younger age ( 2 ). Unfortunately, 79% of the Vickers study population was aged 65 years or older, and the largest proportion (47%) were 70 years or older, an age group for which the US Preventive Services Task Force recommends against PSA screening ( 3 ). Even for men in their 70s with a sufficient life expectancy to undergo screening, we have previously demonstrated that those with a PSA less than 3 ng/mL at age 70 have virtually no risk of lethal prostate cancer ( 4 ). Thus, elderly men with low PSA levels (a major proportion of the PCPT) are not an ideal population in which to study the association between PSAV and the presence of life-threatening prostate cancer.