New research from the Southwest Oncology Group (SWOG) finds that the drug Taxotere can extend the lives of men with advanced prostate cancer who have exhausted all other treatment options. In a study of 770 prostate-cancer patients whose cancer developed resistance to hormone therapy, those who received Taxotere in combination with a drug called estramustine lived 18 months compared to 16 months for men who received standard therapy (mitoxantrone plus prednisone).
New standard of care
Based on these findings and similar results from another study, researchers expect that inclusion of Taxotere in the chemotherapy regimen for terminally ill prostate-cancer patients will become the new standard of care.
"It's satisfying to find a drug that improves survival in this patient population, but we've still got a long way to go," said Dr. Cathy Tangen, investigator in the Public Health Sciences Division and the primary statistician for the study.
The findings were announced last month in at the annual meeting of the American Society of Clinical Oncology in New Orleans, La. Dr. Daniel Petrylak of Columbia University College of Physicians and Surgeons led the study which involved SWOG collaborators from nine other institutions.
Men whose cancer recurs after initial treatment with surgery or radiation typically receive drugs that interfere with the production of male hormones that fuel the cancer's growth. These cancers eventually become unresponsive to hormone-deprivation therapy, and there are no available treatments to extend life after resistance develops.
In addition to improving survival for men with hormone-therapy resistant cancer, the Taxotere regimen had a significant effect on preventing the disease from spreading. Disease-progression-free survival for men receiving Taxotere was six months, as compared to three months for men who did not receive the Taxotere. Toleration for Taxotere was good with no major side effects.
Taxotere, a chemotherapy drug manufactured by Aventis, blocks cancer cells from dividing by immobilizing the cell's internal skeleton. Approved in the United States to treat patients with locally advanced or metastatic breast cancer after failure of prior chemotherapy, Taxotere also treats patients with advanced non-small cell lung cancer. Based on the results of the recent studies, the U.S. Food and Drug Administration in May granted approval of Taxotere in combination with prednisone for men with hormone therapy-resistant prostate cancer.
SWOG is a national clinical-trials organization. Dr. John Crowley directs its Statistical Center, housed jointly in the PHS Division and Cancer Research and Biostatistics, a local non-profit organization.
Dr. Carol Moinpour, investigator in the PHS Division, also took part in the study. Additional investigators took part in the study from their affiliations with: the University of Washington, the Herbert Irving Comprehensive Cancer Center at Columbia University; the SWOG Statistical Center in Seattle; the University of Michigan Comprehensive Cancer Center in Ann Arbor, Mich.; University of California; Davis; Baylor College of Medicine; University of Massachusetts Medical Center, Worcester, MA; the Mayo Clinic; the University of Arkansas; University of California at San Francisco Cancer Center; the Cleveland Clinic Foundation; and the University of Colorado Health Science Center. In addition to SWOG, two other clinical trials groups — Cancer and Leukemia Group B and North Central Cancer Treatment Group — enrolled patients for the study.