Four risk factors that help predict how long men may survive with metastatic prostate cancer could help doctors choose more effective treatments, according to a study led by researchers in the Duke Comprehensive Cancer Center.
"There is a need for identification of accurate and simple-to-use prognostic factors for men with prostate cancer that has spread beyond the prostate, so that patients and their doctors can determine which treatment regimen makes the most sense for their situation," said Andrew Armstrong, M.D., a medical oncologist at Duke and lead investigator on this study. "Our study was aimed at developing accurate predictors which may be used to assist in clinical decision-making and also in planning clinical trials for men whose disease has stopped responding to hormone therapy."
The researchers will present their findings on a poster at the 2009 American Society of Clinical Oncology meeting in Orlando, on Sunday, May 31. The study was funded by the Duke Comprehensive Cancer Center.
Researchers examined the records of more than a thousand patients who were part of a study that led to the approval of the chemotherapeutic drug docetaxel for the treatment of metastatic prostate cancer in 2004. The researchers identified four independent risk factors that predicted whether a patient's PSA levels -- which indicate the presence or absence of cancer -- went down in response to treatment, Armstrong said. The factors included the presence of significant cancer-related pain; anemia (low blood counts); the extent of cancer spread to other organs; and progression of cancer in bone.
"Using these predictors, we were able to assign patients to risk groups of good -- indicating an average survival of about two years; intermediate -- with survival of about 1.5 years -- and poor, with survival of less than a year," Armstrong said. "By knowing a patient's prognosis and expected responses to chemotherapy, we are better able to discuss and determine whether a more or less aggressive treatment plan might be advisable."
Accurately classifying patients' prognoses and their expected responses to therapy may indicate which prostate cancer drugs are promising enough to test in phase III trials, Armstrong said.
"These data are very exciting and we're eager to use this information to accurately estimate what to expect with current therapies, and to better direct novel combination treatments to those men in need of aggressive therapies," he said.
In 2008, over 185,000 men were diagnosed with prostate cancer in the United States and more than 28,000 died of the disease, according to the National Cancer Institute.
Other researchers involved in this study include Susan Halabi and Daniel George of Duke; Ian Tannock of Princess Margaret Hospital in Toronto, Canada; Ronald de Wit of Erasmus University in the Netherlands; and Mario Eisenberger of the Sidney Kimmel Comprehensive Cancer Center at the Johns Hopkins School of Medicine.