Monday, May 13, 2013

Another Use of PSA Tests

In a just released paper the authors note that the PSA levels of a man in his 40s are a strong determinant of whether he will come down with PCa.

The paper states:

Measurement of PSA concentration in early midlife can identify a small group of men at increased risk of prostate cancer metastasis several decades later. Careful surveillance is warranted in these men. Given existing data on the risk of death by PSA concentration at age 60, these results suggest that three lifetime PSA tests (mid to late 40s, early 50s, and 60) are probably sufficient for at least  half of men.

Specifically they note:

In an earlier paper, we showed that PSA concentration at age 60 had a strong association with the risk of death from prostate cancer by age 85 (AUC 0.90), with extremely low risk (≤0.2%) in men with PSA concentration below the median (≤1.0 μg/L). Taken together with our current data, this suggests a simple algorithm for prostate screening. All men with a reasonable life expectancy could be invited for PSA screening in their mid to late 40s. Men with a PSA concentration <1 .0="">µg/L would be advised to return for screening in their early 50s and then again at age 60, whereas men with PSA ≥1.0 µg/L would return for more frequent screening, with literature suggesting repeat tests every two or four years.

The choice of 1.0 μg/L as a tentative threshold might vary according to preference.  At age 60, men with PSA at median or lower—that is, ≤1.0 μg/L (or possibly below the highest quarter, ≤2.0 μg/L, depending on preference)—would then be exempted from further screening; men with a higher concentration would continue to undergo screening until around 70.1

The ROC for this type of test was lacking but survival data was present. The lowering of the age to 40 and the PSA level less than 1 till 60 is interesting and worth following.