FRIDAY, Feb. 13, 2009 (HealthDay News) -- A newly identified biomarker for fatal prostate cancer may help guide men trying to decide whether or not to undergo treatment for the disease.
Men whose levels of ionized serum calcium are in the highest third are three times more likely to die of prostate cancer than those with the lowest levels, said researchers at Wake Forest University School of Medicine and the University of Wisconsin. They also confirmed a previous finding that men with the highest levels of total serum calcium are twice as likely to develop fatal prostate cancer.
The study, published in the February issue of the journal Cancer Epidemiology, Biomarkers & Prevention, is the first to examine the link between fatal prostate cancer risk and pre-diagnosis levels of ionized serum calcium.
The findings highlight the need for more research into the link between calcium and prostate cancer and may also help patients make treatment decisions, the researchers said.
"Many men with this diagnosis are treated unnecessarily," senior author Gary G. Schwartz, an associate professor of cancer biology at Wake Forest University Baptist Medical Center's School of Medicine, said in a university news release.
"Within months of initial diagnosis of prostate cancer, many men opt to undergo either radiation or radical surgery. The problem is, we don't know who needs to be treated and who doesn't, so we treat most men, over-treating the majority," Schwartz explained. "These new findings, if confirmed, suggest that men in the lower and of the normal distribution of ionized serum calcium are three times less likely than men in the upper distribution to develop fatal disease. These men may choose to delay treatment or perhaps defer it altogether."
The findings also suggest "that medicines may be able to help in lowering the risk of fatal prostate cancer by reducing serum calcium levels," he added.
Schwartz noted that diet has little effect on serum calcium levels, which are controlled genetically and are stable over much of a person's life. "These results do not imply that men need to quit drinking milk or avoid calcium in their diets," he said.
The U.S. National Cancer Institute has more about prostate cancer risk.