Prostate cancer therapy poses risk

Study suggests treatment may harm kidneys, questions benefit for men in early stage of disease

Anew study raises a red flag about androgen deprivation therapy commonly used in advanced prostate cancer, suggesting it may increase a patient’s risk of developing acute kidney injury.

The team behind the study says the risk they’ve identified doesn’t outweigh the benefits of the treatment in men who have metastatic prostate cancer.

But they suggest for men who don’t have advanced prostate cancer that has spread to other parts of the body, the risk-benefits formula may not be the same.

The research was led by scientists from McGill University in Montreal and is published in the Journal of the American Medical Association. This type of study cannot prove using the treatment caused acute kidney injury; it can only indicate a possible link between using the therapy and developing the condition.

Laurent Azoulay, PhD, one of the authors, said the study suggest that a sort of treatment creep seen with androgen deprivation therapy in recent years should be reconsidered.

Where the treatment — which drives down the production of hormones that fuel growth of the cancer — was typically used only in men whose cancer had metastasized, now it is sometimes used to treat lowergrade prostate cancers or men who have had what’s called a biochemical recurrence.

That’s when the level of PSA (short for prostate specific antigen) in a man’s blood rises after the man has gone through treatment such as removing the prostate or radiation.

“For this population I think we need to be careful because the randomized controlled trials have not shown any effect of androgen deprivation therapy on survival in these patients, ... on non-metastatic patients,” Azoulay said in an interview.

The study, based on data from the United Kingdom, found what Azoulay called a “pretty strong effect” of the androgen deprivation therapy.

Among prostate cancer patients who didn’t get the treatment, acute kidney injury occurred at a rate of about three cases per 1,000 people per year. Among prostate cancer patients who got the treatment the rate was 7.5 per 1,000 people per year.

Azoulay said the nature of the U.K. databases the group mined allowed them to control for things like whether the men smoked, drank alcohol and other factors that might have increased their risk of acute kidney injury.

But Dr. Ron Wald, a nephrologist (kidney specialist) at Toronto’s St. Michael’s Hospital, said the study did not look for whether the men had chronic kidney diseases. Chronic kidney conditions raise one’s risk of developing acute kidney injury, he said.

While he said he isn’t dismissing the findings, Wald said the study results may have been affected — raised — by chronic kidney disease in some of the men studied.