Aging men with cancer may be more plagued by low levels of testosterone than their tumor-free peers, U.S. researchers said Monday.

Dwindling levels of the male sex hormone were tied to sexual problems as well as decreased physical and emotional wellbeing, they report in the Journal of Clinical Oncology.

“The consequences of low estrogen levels in women who have been treated for cancer, particularly breast cancer, are well-known,” said Victoria Rosenwald, a nurse at Beth Israel Cancer Center in New York City who worked on the study. “But no one has paid much attention to low testosterone levels in men.”

“We are beginning to investigate whether assessment of testosterone levels in male cancer patients should be part of long-term care for survivors,” Rosenwald added in an e-mail to Reuters Health.

Testosterone levels decline naturally as men age, but the consequences of that drop-off are unclear.

Solvay Pharmaceuticals, which funded the new study, makes a prescription ointment for men whose hormone levels dip below 300 nanograms per deciliter of blood, a level widely considered deficient for an adult male.

But skeptics say the problems the ointment is supposed to treat may often just be the symptoms of old age, and there is no agreement about how low the hormone has to go before it becomes an issue.

For the new study, researchers tested more than 400 men with cancers that were unrelated to testosterone.

Nearly half the men had total testosterone levels below 300 nanograms per deciliter. The researchers didn’t compare the men to a control group, but note that all other studies of men without cancer have found some percentage with lowered testosterone levels, but far less than half.

The men in the current study with low testosterone also tended to be overweight or obese, and scored slightly lower on a scale designed to measure quality of life than men with “normal” testosterone levels.

Rosenwald said low testosterone in cancer patients is “a much bigger problem than previously suspected.”

It is unclear why so many cancer patients have low testosterone levels, and the study doesn’t prove that testosterone is at the root of the wellbeing issues reported by the patients.

“We hope to do a careful testosterone replacement trial to see if we can improve their survivorship,” said Dr. Stewart B. Fleishman of Beth Israel Medical Center in New York.

SOURCE:  Journal of Clinical Oncology, online October 25, 2010.