The discovery that microscopic evidence of prostate cancer is present in some men with a normal PSA level (
The discovery that microscopic evidence of prostate cancer is present in some men with a normal PSA level (<4.0 ng/mL) has led some to suggest revising the "normal" PSA level to 2.5 ng/mL. However, researchers at the VA Medical Center, White River Junction, VT, say the cutoff should actually be raised.
The researchers compared PSA data from the 2001-02 National Health and Nutritional Examination Survey (NHANES) of 1,308 American men over 40 years of age with no history of prostate cancer and no current prostate inflammation or infection against data on the 10-year risk of dying of cancer from DevCan, the National Cancer Institute software. Currently, 0.9% of men over age 60 years are expected to die from prostate cancer within the next 10 years.
NHANES data indicated that 1.5 million American men between the ages of 40 and 69 years have PSA levels over 4.0 ng/mL. If the revised PSA level of 2.5 ng/mL were factored in, an additional 1.8 million men would be considered to have abnormal PSA levels, if all were screened. For men >70 years of age, the numbers would be 1.5 and 1.2 million, respectively. In effect, if the lower threshold were used, the number of men defined as having abnormal PSA levels would doubleto almost 6 million.
"Until there is evidence that screening is effective, increasing the number of men recommended for prostate biopsyand the number of potentially diagnosed and treated unnecessarilywould be a mistake," wrote the researchers, led by H. Gilbert Welch, MD, MPH.