According to early results from a randomized controlled clinical trial, men with hormone-sensitive metastatic prostate cancer who received the chemotherapy drug Docetaxel ( Taxotere ) given at the start of standard hormone therapy lived longer than patients who received hormone therapy alone.
The independent Data and Safety Monitoring Committee overseeing the trial recommended to the National Cancer Institute ( NCI ), part of NIH ( national Institutes of Health ), that the study results be made public because a recent planned interim analysis showed prolongation in overall survival.
The study enrolled 790 men with metastatic prostate cancer between July 2006 and November 2012 in a trial known as E3805. All patients started treatment by receiving a form of hormone therapy known as ADT ( androgen deprivation therapy ).
Androgens regulate male sex characteristics and can stimulate prostate cancer cells.
Men received either ADT alone or ADT with the chemotherapy drug Docetaxel every three weeks over a period of 18 weeks.
In addition to examining whether the study participants lived longer with the addition of chemotherapy, researchers looked at whether the extent of a patient’s metastatic disease was high or low at the start of treatment.
Approximately two-thirds of patients had a high extent of disease which meant the disease had spread to major organs such as the liver, had a spread resulting in four or more bone lesions, or both.
A significant improvement in the overall survival was noted favoring the participants who had received Docetaxel chemotherapy in addition to the ADT compared to the ADT alone ( three-year survival rates of 69.0% vs 52.5% respectively ).
Further analysis showed that patients with a high extent of metastatic disease accounted for most of the benefit in the overall survival from Docetaxel plus ADT ( three-year survival rates of 63.4% vs 43.9% for ADT alone ).
Median follow-up to date is two years.
Since Docetaxel has been shown in previous clinical trials to be beneficial in ADT-resistant disease and is approved by the FDA ( Food and Drug Administration ) for treatment of late-stage prostate cancer, it is available for use now. However, because it is a chemotherapy drug associated with some toxicities, its use in combination with ADT at this time should be restricted to patients with high-extent metastatic prostate cancer who are candidates for treatment with Docetaxel.
This is the group of patients who experienced the most benefit in the current analysis.
Further follow-up will be performed on patients with less extensive metastatic disease who participated in E3805 in order to define the effect of this treatment combination on these patients.
According to Christopher Sweeney, Dana Farber Cancer Institute, Boston, the results of this study are practice-changing. There is strong scientific evidence that patients with the most advanced metastatic prostate cancer benefit from the early addition of Docetaxel to ADT and not waiting until the cancer has progressed on hormonal therapy.
It is estimated that over 238,000 men will be diagnosed with prostate cancer in the United States in 2013 and over 29,000 men will die of the disease. ( Xagena )
Source: National Cancer Institute, 2013