New Way to Predict Prostate Cancer Risk
Personalized Risk Calculator May Help Identify Men at High Risk for Prostate Cancer
Feb. 25, 2009 -- For the first time, researchers say they have developed a tool that can help predict a man's future risk of developing prostate cancer.
The personalized risk calculator combines prostate-specific antigen (PSA) test results with additional prostate cancer risk factors, including previous prostate biopsy results, family history of prostate cancer, and prostate size.
"Doctors use PSA to determine whether a man currently has prostate cancer. But the idea of using a combination of baseline PSA levels and specific, known risk factors to give a longer-term view about prostate cancer risk is a new concept that we hope will become part of standard practice," says researcher Monique Roobol, PhD, an epidemiologist in urologic oncology at Erasmus University Medical Center in Rotterdam, the Netherlands.
"Assessing future risk of prostate cancer is important for identifying men who are candidates for more frequent screening," she tells WebMD.
"If future risk is high, you may want to consider the use of drugs [like Proscar] that have been shown to reduce the risk of developing prostate cancer," Roobol says.
PSA and Prostate Cancer Risk
For the study, Roobol and colleagues examined the value of PSA combined with digital rectal exam findings, prostate size, previous prostate biopsy results, family history of prostate cancer, and age at diagnosis in predicting the future risk of prostate cancer among 5,176 men in the Netherlands. The men had an initial screening to assess all of these risk factors and a second screening four years later.
The researchers found that PSA level was the strongest predictor of future prostate cancer risk. Men with PSA levels of 1.5 or higher were seven times more likely to develop prostate cancer over the next four years than those men whose PSA scores were below that level.
Importantly, for any given PSA level, the other factors further modified this risk, Roobol says. A family history of prostate cancer elevated a man's future cancer risk, while a previous negative biopsy and increasing prostate size lowered risk.
For example, a man with a PSA of 1.3 and no previous negative biopsy, a positive family history, and a smaller-than-average prostate size had a 5% chance of developing prostate cancer within four years.