Protein might signal level of prostate cancer risk

A test for a protein made by prostate cancer cells might be able to help doctors predict which patients have dangerous tumors and thus who needs aggressive treatment, researchers have reported.

The test, for a protein called alpha-methylacyl-CoA racemase or AMACR for short, is already often administered to help diagnose prostate cancer in hard-to-read tumor biopsies, said Dr. Mark Rubin of Brigham and Women’s Hospital and Harvard Medical School in Boston. But it also seems to predict which men will have their prostate cancer come back after surgery or radiation therapy and perhaps even which men will die of the disease, Rubin and colleagues wrote in the June issue of Cancer Epidemiology, Biomarkers & Prevention.

For the study, Rubin and colleagues monitored 204 prostate cancer patients from the United States and 188 from Sweden. The Swedish men, beginning in 1977, had opted to watch their prostate cancer carefully, whereas the U.S. men had surgery.

Among the Swedish men, having a low AMACR level was associated with a fourfold higher risk of dying from prostate cancer, Rubin said.

In the American group, having a low AMACR level raised the risk of having the cancer come back by as much as 18 times. There were not enough deaths in the U.S. group to show whether AMACR level predicted death, Rubin said.

Prostate cancer affects more than 200,000 men a year in the United States and will kill 29,000 in 2005, according to the American Cancer Society.