In the retrospective study, the research team examined demographic data, socio-economic factors and tumor biology in relationship to overall survival and cancer-specific survival for a subgroup of 276 PCOS subjects who had localized prostate cancer and received androgen deprivation therapy as their primary treatment. Between 1994 and 1995, a total of 3,486 men were enrolled in PCOS within six months of prostate cancer diagnosis.
The analysis showed that out all the demographic and socio-economic factors considered, overall survival was predicted only by age and certain features of prostate cancer. Tumor biology, which is measured by Gleason score, was the only independent predictor of cancer specific survival. Tumor mass as measured by PSA approached statistical significance as a predictor. Nearly 10 percent of men died from prostate cancer within 5 years of starting hormonal therapy.
"Our study indicates that cancer remains an important contributor to overall mortality in these men, particularly those with high Gleason score and high serum PSA," Beer said. "These data will be useful for men with localized prostate cancer choosing between aggressive treatments such as surgery or radiation, observation and androgen deprivation therapy."
In an earlier OHSU Cancer Institute study of the effectiveness of hormone deprivation as a primary therapy for localized prostate cancer, researchers found that younger men and those with higher-grade tumors are more likely to experience disease progression during treatment. They also found that men with localized prostate cancer on hormone therapy experience a higher than expected rate of bone fractures caused primarily by treatment-related osteoporosis.
"Studies suggest that more needs to be known about the risks and benefits of this treatment before we recommend it to patients with localized disease," Beer said.