New finding suggests prostate biopsy is not always necessary

Some elevated PSA levels in men may be caused by a normally occurring hormone and are not necessarily a predictor of the need for a prostate biopsy, according to results of a recently published study.

Parathyroid hormone, which regulates calcium in the blood, can elevate PSA levels in healthy men who do not have prostate cancer. These "non-cancer" elevations in PSA could cause many men to be biopsied unnecessarily.

Study co-authors Gary G. Schwartz, PhD, MPH, of Wake Forest University, Winston-Salem, NC, and Halcyon G. Skinner, PhD, MPH, of the University of Wisconsin, Madison, analyzed data from 1,273 men who participated in the National Health and Nutrition Examination Survey 2005-2006, and who did not report any current infection or inflammation of the prostate gland, prostate biopsy in the past month, or history of prostate cancer at the time of the survey.

After adjusting for age, race, and obesity, the researchers found that the higher the level of parathyroid hormone in the blood, the higher the PSA level. In men whose parathyroid level was at the high end of normal, the PSA level was increased by 43%, putting many in the range for the urologist to recommend a biopsy.

The finding is especially significant for African-American men, according to the authors. About 20% of African-American men have elevated parathyroid hormone levels, compared with about 10% of Caucasian men.

This finding "could help scientists refine the prostate cancer screening test to better differentiate between those men who need to be biopsied and those who might be spared the procedure," Dr. Schwartz said. "It’s likely that there are a lot of men out there with elevated PSAs that may be due to elevated parathyroid hormone rather than prostate cancer."

Results of the study appeared in Cancer Epidemiology, Biomarkers & Prevention (2009; 18:2869-73).