The appropriate age at which to end prostate cancer screening is controversial, with different organizations issuing different recommendations. Data from a new study suggest that screening might be safely discontinued in men ages 75 and older who have prostate specific antigen (PSA) levels of less than 3 ng/ml—a cutoff point lower than that proposed in previous studies.
PSA testing is common in older men despite evidence that those without aggressive prostate cancer are unlikely to benefit from diagnosis and treatment, write researchers from the Johns Hopkins School of Medicine and the NIA’s Intramural Research Program in Baltimore. To help weigh the risks and benefits of PSA testing in this population, they studied 849 men ages 40 and older who participated in the NIA Baltimore Longitudinal Study of Aging. Of the group, 122 had prostate cancer and 727 did not.
Researchers determined the probability of high-risk prostate cancer developing in 5-year age groups starting at age 60, sorting the data by PSA cutoffs that ranged from less than 1 ng/ml to 3.5 ng/ml or greater. There is no PSA value below which a diagnosis of prostate cancer can be excluded, the authors note.
Participants of all ages with a PSA of 3 ng/ml or more had an increasing probability of high-risk prostate cancer or death from the disease, the study found. Among those older than age 75, none with a PSA of less than 3 ng/ml died of prostate cancer, and only one got high-risk cancer. Of the older men with a PSA of 3 ng/ml or greater, 10 died of prostate cancer and 18 had high-risk disease.
Men 75 to 80 years old with a PSA less than 3 ng/ml are unlikely to develop or die of aggressive prostate cancer during their lifetimes, the researchers conclude. This finding suggests that PSA testing might be safely discontinued for these men, avoiding unnecessary treatment.