"While current prostate cancer screening practices are good at helping us find patients with cancer, they unfortunately also identify many patients who don't have cancer. Three out of four men who receive a prostate biopsy after an abnormal prostate screening test do not have cancer at all," said Mark Garzotto, M.D., principal investigator, member of the OHSU Cancer Institute and director of urologic oncology at the Portland Veterans Affairs Medical Center. "So the challenge has been to develop a model that both predicts which men will have prostate cancer and spares men without prostate cancer from unnecessary biopsies."
Prostate cancer is the most common cancer in men and the second leading cause of cancer-related death in American men. Overall, roughly one in six men will develop prostate cancer during his lifetime. Prostate biopsy can be a source of patient discomfort, bleeding and infection, and can burden the health care system with extra costs.
This new model -- a nomogram -- predicts the detection of prostate cancer in men with a prostate specific antigen (PSA) level of less than or equal to 10 ng/ml. Prostate cancer screening using a PSA test has been associated with a decline in prostate cancer deaths in the United States.
About 10 percent of men who are tested will have an elevated PSA. However, PSA becomes specific only when it exceeds 10 ng/ml. When the PSA is modestly elevated from 4 to 10 ng/ml, which it is in the majority of cases, it is associated with cancer in about 25 percent of men who are biopsied. Attempts to develop predictive models for PSA values less than 10 have been made, but to date they have been u
Contact: Rachel MacKnight
Oregon Health & Science University