Discovery shows low PSA might not always be good

Without a home to go back to during the Balkans War in the 1990s, Andjela Drincic, M.D., made a discovery while working for the Veteran’s Administration in Grand Island.

A specialist in endocrinology, Dr. Drincic was practicing general medicine, but because of her specialty, she noticed some of her patients with life-threatening pituitary tumors and associated hormone deficiencies had low prostate-specific antigen, or PSA.

“I thought, ‘Boy isn’t this interesting,'” said Dr. Drincic, a professor of internal medicine in the UNMC Department of Internal Medicine Division of Diabetes, Endocrine & Metabolism. “This is not accidental. The whole point of PSA is to check if it’s too high, which can signal prostate cancer. But no one ever said if it’s too low that it can it be a bad thing.”

She published the finding. After joining Creighton University and also working for the Omaha VA, she applied for and received a research grant to learn more.

Her study goal was to evaluate pituitary function in men with a low PSAs and test the hypothesis that low PSA is associated with low testosterone or other hormone deficiencies.

Sixty-four men were divided into a low-PSA group (less than .1 ng/ml) and normal-PSA group (1 to 4 ng/ml) without known prostate disease.

The study found men with low PSA have significantly higher rates of low testosterone — also known as hypogonadism, and low growth hormone status compared with those with normal PSA. Almost 50 percent had low testosterone levels, 20 percent had low growth hormone status and 11 percent had multiple hormonal deficiencies in their pituitary gland, which is potentially life-threatening.

Four study participants with low PSA showed reason to suspect pituitary disease. An MRI scan found three of four patients had large benign tumors in the pituitary gland which required treatment, including hormonal replacement.

Dr. Drincic said the pituitary gland, a pea-sized gland located at the base of the brain, controls important hormone glands, including the thyroid, adrenal, testicles and ovaries. It secretes life-sustaining hormones and can be affected by tumors causing hormonal deficiencies and can impact sight as well.

Her study, “Pituitary Evaluation in Patients with Low PSA” recently appeared in Endocrine Practice. The UNMC Department of Internal Medicine recognized her work as publication of the quarter. Her study also was recently featured as one of the top articles by Medscape, a website providing access to medical information for clinicians.

Tom Tape, M.D., chief of the UNMC division of general internal medicine, said the PSA is a very commonly done test. “Andjela’s work points to fundamentally important information that we have likely been missing,” he said.

“It’s pretty amazing,” said Dr. Drincic, who specializes in treating pituitary tumors. “Just because you have a low PSA doesn’t mean it’s always good news. You may have a serious hormonal deficiency besides low testosterone or a life-threatening condition. If you have less than .1 PSA, you should be evaluated for hormonal deficiencies including low testosterone. An MRI is needed if there’s more than one hormonal deficiency to look for tumors in the pituitary.”