The Low Down on PSA Levels

There has been a dizzying amount of information lately about using prostate-specific antigen (PSA) testing to screen for prostate cancer.

New evidence shows that PSA levels — even relatively low ones — can be predictors of prostate cancer.

Research out of the University of Colorado Cancer Center finds that PSA levels between 1.5-4.0 ng/ml can increase a man's risk of prostate cancer by 15-fold.

Discuss PSA testing with your doctor.

“We call this the ‘early warning PSA zone’,” says the study's lead author, E. David Crawford, MD, an investigator at the CU Cancer Center.

A commonly held belief is that a high level PSA — over 4.0 ng/ml — is a predictor of the disease. In fact, only about 30 percent of men with this level actually have the disease.

Levels under 4.0 were considered to be in the normal range, meaning there was little or no cancer risk.

This current study involved 21,502 men over the age 40 who had a normal PSA range of 1.5-4.0 ng/ml. They were tested again four years later.

Nearly 8 percent of the men with levels in this range were later diagnosed with the disease, compared to 0.51 percent of men who had lower concentrations.

Risks were higher for African-American men, who had a 19-fold increased risk of the disease with PSA levels of 1.5 ng/ml and above.

“This is a robust finding,” Dr. Crawford says, “and it has the potential to make doctors and other caregivers rethink how we interpret PSA levels.”

The study was published in 2011 in the British Journal of Urology International, which chose this finding as the top publication for the year.