Prostate biopsy not always needed when PSA elevated
Researchers now say that not all men with elevated PSA (prostate specific antigen) levels need prostate biopsy to test for prostate cancer. A naturally occurring hormone can also raise PSA levels, and the test may not always mean prostate biopsy should be performed.
The findings come from researchers at Wake Forest University School of Medicine and the University of Wisconsin-Madison, led by Gary G. Schwartz, Ph.D., M.P.H. The PSA test is widely used to detect prostate cancer in men, but Schwartz says the test detects more than just cancer.
"PSA picks up any prostate activity, not just cancer. Inflammation and other factors can elevate PSA levels. If the levels are elevated, the man is usually sent for a biopsy. The problem is that, as men age, they often develop microscopic cancers in the prostate that are clinically insignificant. If it weren't for the biopsy, these clinically insignificant cancers, which would never develop into fatal prostate cancer, would never be seen.”
Elevated PSA levels can lead to unnecessary prostate biopsy. The researchers found that parathyroid hormone, a regulator of calcium in the body, can also lead to higher PSA levels in men who are healthy. In turn, prostate biopsy might lead to overtreatment of prostate cancer. The side effects for men can include impotence and urinary incontinence.
For the study, researchers examined 1,273 men who participated in the National Health and Nutrition Examination Survey 2005-2006. None of the men had prostate cancer, inflammation, or had a recent prostate biopsy.
The researchers found an association between elevated parathyroid hormone levels and elevated PSA levels, after adjusting for age, race, and obesity. Higher levels of parathyroid hormone levels paralleled elevated PSA levels. When parathyroid hormone levels were at the high end of normal, PSA levels were elevated by 43 percent – a point that urologists would likely recommend prostate biopsy.
As men age, parathyroid hormone levels go up. The hormone is also higher in blacks and among obese men. Study co-author, Halcyon G. Skinner, Ph.D., M.P.H., of the University of Wisconsin-Madison explains the chances of prostate biopsy and over treatment are especially high among blacks, saying the findings "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."
A study, published in the British Journal of Cancer, September 2009, suggests that there is no need to treat the majority of prostate cancers. Researchers isolated the Hsp-27 protein, a biomarker of aggressive prostate cancer that scientists say can be used to determine when prostate cancer requires treatment; potentially sparing men decreased qualify of life associated with cancer treatment.
The study is the first to show that parathyroid hormone promotes prostate cell growth. Past studies linked parathyroid hormone to prostate cancer cell growth.
Elevated PSA levels might not mean prostate biopsy is necessary. The findings are important to spare healthy men from prostate cancer treatment that leads to side effects of impotence and urinary incontinence. The study suggests that prostate biopsy is not always needed when PSA levels are elevated. Higher parathyroid hormone levels can also elevate PSA levels in men.
Cancer Epidemiol Biomarkers: doi:10.1158/1055-9965.EPI-09-0730