Chemotherapy Improves Survival and Quality of Life for Patients with Hormone-Refractory Prostate Cancer

June 7, 2004

Two new studies demonstrate that docetaxel (Taxotere) extends survival and relieves pain in men with prostate cancer that does not respond to hormone therapy. This type of cancer is called hormone-refractory, or androgen-independent, prostate cancer. Hormone therapy is a primary treatment for prostate cancer, but often loses its effectiveness over time.

The results of the first study showed a 20% survival advantage with a new chemotherapy regimen of docetaxel and estramustine (Estracyte) when compared with the current standard therapy of mitoxantrone (Novantrone) and prednisone in a randomized, phase III trial of more than 700 men. In addition, the new combination increased the time it took for the disease to progress: six months for the men who received docetaxel/estramustine, and three months for the men who received mitoxantrone/prednisone. For late stage prostate cancer, an increase of three months' survival time is considered significant. The men receiving the docetaxel/estramustine combination experienced more serious side effects, but the number of treatment-related deaths did not increase.

"The findings show that docetaxel can effectively treat hormone-refractory prostate cancer. Docetaxel-based therapy is now a treatment to build upon," said Daniel Petrylak, MD, lead author of the trial and Associate Professor of Medicine at Columbia University College of Physicians & Surgeons, Director of Genitourinary Oncology Program at New York Presbyterian Hospital in New York City.

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A second study of 1,006 men with hormone-refractory prostate cancer showed that docetaxel plus prednisone given every three weeks improved overall survival, reduced prostate-specific antigen (PSA) levels, and improved pain symptoms. In addition, this treatment had relatively few side effects, the most common one being neutropenia (a low number of white blood cells).

In this study, researchers compared three drug regimens: two different doses of docetaxel (once a week vs. once every three weeks) plus prednisone, or mitoxantrone plus prednisone (given every three weeks). At a median follow-up time of 20.7 months:

• Survival was significantly longer for men who received docetaxel once every three weeks (18.9 months) compared with those who received docetaxel weekly (17.4 months) or mitoxantrone plus prednisone every three weeks (16.5 months).
  
  
• In men who received docetaxel every three weeks, 45% had a reduction in their PSA levels, compared with 48% of the men who received docetaxel weekly, and 32% of the men who received mitoxantrone plus prednisone every three weeks.
  
  
• Men who received docetaxel every three weeks experienced greater pain relief (33%) compared with those who received weekly docetaxel (31%) or mitoxantrone plus prednisone every three weeks (22%).

"This is the first evidence of a survival advantage with chemotherapy in phase III trials in patients with hormone-refractory prostate cancer," said Mario Eisenberger, MD, lead author of this study and R. Dale Hughes Professor of Oncology and Urology at Johns Hopkins School of Medicine in Baltimore, Md. "We have a real chance to finally develop a treatment approach that is not based primarily on hormonal therapy and make a real long-term impact on this disease."

What This Means For Patients

These two studies demonstrate for the first time that chemotherapy improves survival and relieves pain in prostate cancer that no longer responds to hormones. This type of prostate cancer has been difficult to treat in the past, and now men with this cancer have better treatment options. On May 19, 2004, the U.S. Food and Drug Administration approved docetaxel for use in combination with prednisone for the treatment of metastatic, hormone-refractory prostate cancer. Docetaxel-based chemotherapy will likely become the new standard treatment for men with hormone-refractory prostate cancer.