Recently, a large trial in Europe showed that PSA -based screening reduces the number of deaths from prostate cancer by at least 20 percent. This was a landmark, the first randomized study to prove definitively that PSA screening saves lives.
However, this study, the European Randomized Trial of Screening for Prostate Cancer, reported that at nine years, 1,410 men needed to be screened and 48 treated to prevent just one prostate cancer death. Jumping to conclusions here may be a bit hasty, says Stacy Loeb, M.D., “because nine years is too early to look at prostate cancer deaths. Also, everyone agrees that men who are unlikely to live at least 10 years should not undergo PSA screening, or be put through aggressive treatments.”
Investigators from Hopkins, the National Institute on Aging, and Northwestern University organized a multi-institutional collaboration to determine how these numbers would change over time. Based on data from the European trial, they built a mathematical model to look at death from prostate cancer up to 12 years of follow-up.
“It became clear that as time went on, there was an even greater difference in the rates of prostate cancer death between the men who were screened, and the men who did not have regular screening,” says Loeb, the study’s lead author. “Further, by 12 years, only 503 needed to be screened and 18 men treated to prevent one prostate cancer death.”
For breast cancer, she adds, “10 women need to be screened and treated to save a life with mammography. It is great news for men and their families that we have such an effective way to identify prostate cancer at a curable stage.”