ANCHOR LEAD: HOW WILL OBESITY AFFECT A CHANGING PSA LEVEL? ELIZABETH TRACEY REPORTS
Prostate specific antigen or PSA is used to screen men for prostate cancer, with many physicians saying that looking at PSA levels over time, the so called PSA velocity, is most predictive. A recent Johns Hopkins study has found that PSA levels are always lower in obese men, but Alan Partin, one of the study’s authors, says that shouldn’t affect velocity.
PARTIN: Over the last five years we began to notice that obese men presented with more advanced prostate cancer, and in trying to understand why that was, we found out that the PSA test was not as useful in these men. Obese men, quite simply, have a higher blood volume, and the PSA gets diluted, thus we detect it less often, and what we’ve discovered in this large study is that we probably need to correct PSA values in men for how obese they are. :29
Partin says all obese men should be carefully evaluated.
PARTIN: I don’t think that it will inhibit the PSA velocity’s ability to detect prostate cancer, it may actually enhance its ability to detect prostate cancer because we’ll understand that even a low PSA in an obese man, if it’s changing, suggests more that they should be tested. :17
Partin and colleagues are hard at work to normalize PSA values to account for differences in body mass index. I’m Elizabeth Tracey reporting.