Prostate Cancer Screening - Does It Help? Two major studies, one in the U.S. and one in Europe, have found that yearly P.S.A. (prostate-specific antigen) blood tests do not significantly reduce prostate cancer death rates. What's more, men with high P.S.A. readings, which can indicate less serious ailments as well as malignant prostate cancer, will sometimes undergo painful surgery or radiation therapy when no intervention is needed. As with other cancers, slow-growing prostate tumors may pose little threat or even disappear on their own, while fast-growing tumors often become untreatable before being discovered through screening. Some experts now say that men should weigh the hazards and benefits of treatment when determining whether they want to be tested.