Primary androgen deprivation therapy (PADT) in men with localized prostate cancer appears to offer no survival benefit.
Men who received androgen deprivation as their primary treatment instead of surgery or radiation did not live any longer than those who received no treatment, a study of more than 15,000 men with early-stage disease found.
Study authors, led by scientists at Georgetown Lombardi Comprehensive Cancer Center in Washington, say that the risks of serious adverse events associated with the treatment “mitigates against any clinical or policy rationale for use of primary androgen deprivation therapy in these men.”
The findings, reported online in the Journal of Clinical Oncology (March 17, 2014), draw from cancer registries linked with extensive electronic medical records in three large integrated health plans. Men included in the study had localized prostate cancer and did not have surgery or radiation therapy.
After adjusting for demographic and clinical characteristics, PADT was not associated with risk of all-cause mortality (hazard ratio [HR]: 1.04; 95% CI: 0.97-1.11) or prostate cancer–specific mortality (HR: 1.03; 95% CI: 0.89-1.19), the researchers reported. PADT was associated with a lower risk of all-cause mortality only among the subgroup of men with a high risk of cancer progression (HR: 0.88; 95% CI: 0.78-0.97).
“This study is the most comprehensive study on the effectiveness of PADT for men who forgo radiation and surgery for their localized prostate cancer, and it tells us there is no strong reason to use it in most patients,” said lead investigator Arnold Potosky, PhD, of Georgetown Lombardi. “We found only a small survival benefit for primary androgen deprivation therapy compared to no therapy in men diagnosed with higher-risk localized prostate cancer.”
Despite the lack of randomized trials to test its effectiveness, recent studies have reported it as the second most common treatment, after radiotherapy, for clinically localized prostate cancer among older men age 65 years and older. The study did not compare androgen deprivation therapy directly to either surgery or radiation therapy. It also did not probe the reasons why physicians prescribe the treatment in this setting, although it was much more common in older men and those with higher risk of disease progression.
“Primary androgen deprivation therapy may be preferable to some men with early-stage prostate cancer who would prefer to do something rather than watch and wait for further signs of progression to occur later and then need treatments,” Dr. Potosky said. “However, using PADT by itself immediately after diagnosis in the hopes of limiting cancer’s progression does not extend survival, according to this study.”