Earlier PSA testing may predict long-term death risk from prostate Ca

A PSA test taken for the first time between the ages of 44 and 50 years can predict the likelihood that a man will die from prostate cancer over the next 25 to 30 years, according to researchers at Memorial Sloan-Kettering Cancer Center, New York.

The findings, which will be presented at the 2011 American Society of Clinical Oncology annual meeting, suggest that more than half of men could forego annual PSA testing and have just three PSA tests in their lifetime. Men between the ages of 44 and 50 years with higher PSA levels are at high risk for aggressive prostate cancer and should continue to receive PSA tests and screening as necessary, according to the study authors.

"This research helps us distinguish between those men who may benefit from regular PSA screening for prostate cancer and those men who may not need to be screened so frequently," said lead author Hans Lilja, MD, PhD. "Instead of testing all men each year or every 2 years, screening and surveillance efforts can be focused on early detection of prostate cancer in those men who are found to be at high risk of death from the disease."

The team analyzed archived blood samples from 12,090 men between the ages of 44 and 50 years who provided blood between 1974 and 1986, and repeat samples from 4,999 of those men 6 years later as part of the Malmö Preventive Project in Sweden. Blood samples from 1,167 60-year-old men involved in the Malmö project were also included. All of the men who provided blood for the samples had never received any screening for prostate cancer.

Analyzing each of the three samples-men ages 44 to 50, 51 to 55, and age 60-the researchers determined median PSA levels to serve as baselines distinguishing between low risk and high risk for developing aggressive prostate cancer. The researchers found that a PSA level below the median between the ages of 44 and 50 years was associated with a very low risk of prostate cancer death or metastases within 15 years, although it did not rule out lifetime risk. By age 60, the risk decreased significantly to 0.5% in those men with a PSA level below the median.

This study indicates a new screening interval, suggesting that men should start the screening discussion with their physician at an earlier age and receive their first PSA test between the ages of 44 and 50 years, the researchers say. If the men are found to be at low risk, they do not need to undergo frequent PSA tests. Instead, the study suggests that these men should receive a second PSA test between the ages of 51 and 55 years, and if their PSA levels are still found to be low, they should receive their final PSA test at 60 years of age.