For decades, millions of men with early prostate cancer have been placed on drug therapy to suppress their production of testosterone, despite such significant side effects as impotence, diabetes and bone loss. Now a large new analysis has concluded that so-called androgen deprivation therapy does not extend the lives of these patients.
"There are so many side effects associated with this therapy, and really little evidence to support its use," said Grace L. Lu-Yao, a researcher at the Rutgers Cancer Institute of New Jersey and the lead author of the report, published last week in JAMA Internal Medicine. "I would say that for the majority of patients with localized prostate cancer, this is not a good option."
Ms. Lu-Yao and her colleagues followed tens of thousands of men with early prostate cancer for as long as 15 years and found that those who received androgen deprivation therapy lived no longer on average than those who did not.
The study joins a growing body of evidence indicating that for many men with early prostate cancer, avoiding testosterone-suppressing drugs altogether may be better than grappling with their potentially devastating toll.
One expert who was not involved in the new study, James M. McKiernan, acting chairman of urology at NewYork-Presbyterian Hospital/Columbia University Medical Center, said its findings were "eye-opening and even alarming."
"This isn't the first study that suggests that there's no added benefit to this therapy," Dr. McKiernan said. "But there are still a fair number of doctors recommending it and patients receiving it."
Every year, roughly a quarter-million new cases of prostate cancer are diagnosed in the United States. More than 90 percent of these men have an early form of the disease in which the cancer has not spread and is classified as low-risk.
Drugs to suppress hormones like testosterone -- essentially inducing chemical castration -- can shrink prostate cancers or cause them to grow more slowly in men with more advanced or aggressive disease. Androgen deprivation can help improve survival in these patients when combined with radiation or other treatments.
But experts have become increasingly concerned about the widespread use of this treatment in men with early-stage disease, particularly older patients whose slow-growing cancer is unlikely to have serious health consequences.
In the 1990s, use of these drugs rose sharply in patients of all ages and stages of the disease, and especially in older patients. Today it is estimated that at least a quarter of all patients older than 75 are chemically castrated.
Men are usually put on the drugs for life, which substantially raises their risk of fractures, hot flashes, diabetes and heart disease.
The new study involved more than 66,700 men with prostate cancer who were 66 or older. The researchers compared men in areas of the country where the drugs were frequently prescribed with men in other regions where the drugs were less commonly used. Overall, they found that the drugs were not associated with greater long-term survival.
The findings echo those of another large, randomized trial carried out in Europe that found the hormone treatments did not benefit early-stage patients assigned to take them. The drugs improved survival only in men with a more aggressive form of the disease.
An editorial accompanying the new study, written by physicians at the Dana-Farber Cancer Institute in Boston, said it was now clear that there was "no compelling evidence" to justify using the drugs on men with early-stage prostate cancer.
The editorial called the practice "a prime candidate" for inclusion in the nationwide Choosing Wisely campaign, an initiative started by the American Board of Internal Medicine Foundation and other groups to warn doctors and patients about unnecessary medical tests and procedures.