“For those men with prostate cancer that had not metastasized, adding docetaxel to hormone therapy reduced the risk for recurrence by 40%, which both improves quality of life and saves cost for treating cancer recurrence,” said lead study author Nicholas D. James, MD, PhD, a professor of clinical oncology at the University of Birmingham, United Kingdom. “We already knew that docetaxel prolongs survival for men with metastatic prostate cancer, but this improvement in quality of life and reduction in subsequent treatment, and therefore costs, in non-metastatic disease is somewhat surprising and may cause clinicians to rethink how and when they use docetaxel to treat prostate cancer.”About the Study
The STAMPEDE (Systemic Therapy in Advancing or Metastatic Prostate Cancer: Evaluation of Drug Efficacy) trial has now enrolled over 9,000 men with advanced (non-metastatic and metastatic) prostate cancer since October 2005 and has looked at nearly a dozen different drugs to treat the disease.
An analysis in 2016 showed that the 592 men on the trial who received docetaxel lived, on average, 10 months longer than men on standard therapy. This current report is a health economic analysis that looked at health-related quality of life and cost-effectiveness of the addition of docetaxel and prednisolone to hormone therapy, compared to hormone therapy alone (standard of care).
Using a standardized self-reporting tool commonly used in Europe (EuroQol EQ-5D), the researchers asked the trial participants to rate, on a five-point scale, five aspects of their health: mobility, how well they could care for themselves, their ability to perform their usual daily activities, their pain and discomfort levels, and their levels of anxiety and depression.
Based on these reports, the authors were able to model changes in a man’s:
• predicted length of survival;
• quality-adjusted life years (QALY), a value that measures the quality and the quantity of life lived where one QALY is a year of perfect health; and
• incremental cost-effectiveness, which is also based on QALY as it assesses the cost-benefit of a medical treatment.
For the men with metastatic disease that had spread to organs outside of the pelvis (M1 disease), if they received docetaxel, their predicted survival was 0.89 years longer compared to men who received only hormone therapy, and the quality of life was preserved 0.51 years longer. For men with non-metastatic disease (M0), predicted survival was 0.78 years longer and quality of life was preserved for an additional 0.39 years with docetaxel.
“One of the key aspects we struggled with was how to truly measure quality of life,” said Dr. James. “How does one measure wanting to live a few more months to see a grandchild born even if the therapy results in difficult side-effects? Although there is a concern about side-effects, primarily nausea and fatigue, it is clear that avoiding or delaying recurrence outweighs the upfront toxicity of chemotherapy and adds enough to overall quality of life so that using docetaxel is beneficial.”
Adding docetaxel to the standard-of-care treatment regimen was also found to be cost-effective for both non-metastatic and metastatic disease. The investigators estimate that the annual cost of giving docetaxel in the United Kingdom is about 5,000 British pounds (roughly $6,750 U.S. dollars) per QALY gained. Researchers note that the potential cost saving benefit from delaying or avoiding recurrence in the United States should be the same, if not greater, due to higher drug prices in the United States.
Since STAMPEDE began, several newer drugs have come on the market, including abiraterone, an oral steroid synthesis inhibitor, which was approved by the U.S. Food and Drug Administration in 2011. Abiraterone has been tested in STAMPEDE, and the authors plan to report cost-effectiveness and quality-of-life measures for this treatment later in 2018.
The investigators note that docetaxel is still mandated for use by the National Health Service, but in other countries, including the United States, the choice between using abiraterone or docetaxel is less clear, especially since abiraterone is more easily taken because it comes in pill form. A course of docetaxel costs an average patient 5,000 British pounds a year, compared to 24,000 pounds for abiraterone.
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