PSA at 40?

PSA at 40?Prostate Specific Antigen (PSA) is a widely-used screening test for prostate cancer. Unfortunately these tests cause a lot anguish: an elevated PSA doesn't usually mean prostate cancer (only 25-30 percent of cases with elevated PSAs are prostate cancer), but it often means a biopsy and a lot of angst.According to the National Cancer Institute:

Using the PSA test to screen men for prostate cancer is controversial because it is not yet known if this test actually saves lives. Moreover, it is not clear if the benefits of PSA screening outweigh the risks of follow-up diagnostic tests and cancer treatments. For example, the PSA test may detect small cancers that would never become life threatening. This situation, called overdiagnosis, puts men at risk for complications from unnecessary treatment such as surgery or radiation.

So I was a little surprised to read that the authors of a new study are advocating starting PSA testing even earlier: at age 40 rather than age 50. It's counterintuitive, but the reasoning is that if a patient has a longer baseline it will be easier to tell from the PSA whether they in fact have cancer. For example, as I read in the Wall Street Journal (Beginning Prostate-Cancer Screening At Age 40 Holds Benefits, New Data Show):

[A] 40-year-old man who has a PSA of 0.8 at 40 and then a score of 2 a few years later likely is at high risk for aggressive cancer. But if he has a score of 2 and no prior PSA test, he likely would be told he's at low risk. By the time his PSA score reaches 4 and doctors decide to intervene, it might be too late to save him.Meanwhile a 50-year-old man with a PSA of 4 likely will be told he needs a biopsy. However, if that man at the age of 40 had a PSA of 2, the 10-year trend suggests he likely doesn't have cancer or at least not an aggressive cancer."It's the same threshold of 4," says Dr. Carter. "But the two people got to that threshold at much different rates. I see this as a way to decrease the men who have biopsies and identify the men with lethal disease."

The logic sounds good, but it makes me nervous. I'm turning 40 next year and I think I'll wait till I turn 50 to start testing. (I'll see what my doc thinks before deciding.) I don't have any of the prostate cancer risk factors and I'm as scared of having a false positive as I am of prostate cancer itself. In 10 years, when I'm 50 maybe there will be a better test and it won't matter that I don't have baseline PSA data.