Docetaxel added to hormone therapy improves survival in prostate cancer

Last Updated: 2015-08-05

By Gene Emery

NEW YORK (Reuters Health) - Supplementing androgen-deprivation therapy with docetaxel increases survival time by 39% in men with metastatic hormone-sensitive prostate cancer, according to a study of 790 patients.

Median overall survival for the newly diagnosed patients was 57.6 months with the combination therapy versus 44.0 months with androgen-deprivation therapy (ADT) alone (p<0.001). Median time to disease progression, as measured biochemically, symptomatically, or radiographically, was 20.2 months in the docetaxel group compared with 11.7 months with ADT.

The findings were published online August 5 in the New England Journal of Medicine. They were originally announced in June of last year at the annual meeting of the American Society of Clinical Oncology in Chicago.

"The world has been waiting for the publication of the results so doctors can submit them to their regulating authority to update guidelines," chief author Dr. Christopher Sweeney, of the Dana-Farber Cancer Institute in Boston, told Reuters Health by phone.

He said a separate study, known as STAMPEDE, that was presented at this year's ASCO meeting, has shown improvements of the same magnitude. Those results are awaiting publication.

Docetaxel was given in six cycles three weeks apart at a dose of 75 mg per square meter of body-surface area. A placebo was not used in the control group.

Currently, "docetaxel isn't added until later in the game" when hormone blockers stop working, which is typically after three years, Dr. Sweeney said.

"We were surprised at how substantial the benefit was," he said. Additional survival was "13 months in the overall group and 17 months in those with a higher burden of disease."

Docetaxel therapy "is not for everyone. The patient has to be fit for chemotherapy so they can tolerate the side effects profile," he said. "A very frail geriatric patient would probably not be a candidate."

Patients need reasonable kidney and liver function and nerves not irritated by another illness such as diabetes. Bone marrow suppression is a primary concern "and in the group we treated, 8% required hospital admission for supportive care," said Dr. Sweeney.

About 4% experienced fatigue or flu-like symptoms for about a week before recovering.

"Patients find most of the side effects resolve four weeks after the last dose," he said.

The cost of the therapy is relatively small because docetaxel "is generic and cheap," said Dr. Sweeney. "We haven't done a cost-benefit analysis, but patients live substantially longer. We're talking 13 months overall for a drug that costs a few thousands of dollars for the six months of treatment."

An earlier, similar study, called GETUG-AFU 15, published in Lancet Oncology in 2013, found no increase in survival for combination therapy.

Dr. Sweeney said the reason may be that "the two studies were done in different eras," and if a patient progressed during the earlier trial, "they didn't have access to newer treatments."

The study was done by the Philadelphia-based ECOG-ACRIN Cancer Research Group.

SOURCE: http://bit.ly/1MNqqPx

N Engl J Med 2015.