June 4, 2012 (Chicago) -- Taking a break from hormone therapy can shorten the lives of some men with metastatic prostate cancer, researchers say.
Many men take a break from hormone therapy -- aka androgen-deprivation therapy or ADT -- to lessen its often debilitating side effects.
ADT -- which turns off production of the male hormone testosterone that fuels the growth of prostate tumors -- is a first line of treatment for metastatic disease (that has spread beyond the prostate).
But because hormone therapy blocks male hormones, it can lead to loss of sexual function and severe hot flashes. Over time, weakened bones (osteoporosis) and heart problems may develop.
But in a new study of more than 1,500 men tracked for nearly a decade, patients with minimal cancer spread given continuous ADT lived an average of about two years longer than those given intermittent (on-again, off-again) ADT.
Interrupted ADT should no longer be recommended as an initial treatment, says researcher Maha Hussain, MD, of the University of Michigan Comprehensive Cancer Center in Ann Arbor, Mich.
"Continuous therapy continues to be the standard of care," she tells WebMD.
Hussain reported the findings here at the annual meeting of the American Society of Clinical Oncology.
Prostate cancer is the second most common cancer in men, with nearly 242,000 cases diagnosed each year in the U.S., according to the American Cancer Society. Skin cancer is the most common.
Previous smaller studies suggested that intermittent hormonal therapy -- stopping and restarting treatment periodically -- was as effective as continuous therapy, but with a lower risk of these side effects, says Bruce Roth, MD, a prostate cancer specialist at Washington University School of Medicine in St. Louis. Roth, who was not part of the study, moderated a news briefing at which the findings were presented.
As a result, interrupted ADT became widely used in the U.S., he tells WebMD.
"But this study for the first time indicates that there is a price to pay. Men need to ask themselves if they are willing to trade hot flashes for two years of their lives," he says.