Prostate cancer research may be faster with PSA endpointsA new study from Columbia University Medical Center researchers at NewYork-Presbyterian Hospital/Columbia, who are members of the Southwest Oncology Group (SWOG), suggests that certain changes in prostate-specific antigen (PSA) levels may serve as surrogate endpoints for prostate cancer survival. Researchers looking to speed up the process of clinical trials have suggested that these biomarkers could be used to measure treatment efficacy.
Currently, the U.S. Food and Drug Administration accepts only survival as an endpoint of measure. Survival as a primary endpoint was used in phase III studies of novel chemotherapeutic drugs for men with androgen-independent prostate.
Daniel P. Petrylak, M.D., associate professor of medicine at Columbia University College of Physicians & Surgeons and director of the genitourinary oncology program at NewYork-Presbyterian/Columbia, together with his research team, retrospectively analyzed results of 551 men with prostate cancer treated in the Southwest Oncology Group Protocol S9916. By reviewing the clinical trial, it was noted that there were several different changes in PSA levels, which could possibly serve as surrogate endpoints for survival.
The authors observed that the risk of death, in men whose serum PSA levels declined by at least 30 percent in the first three months of treatment, was reduced more than 50 percent. Findings are published in the Journal of the National Cancer Institute (April 19, 2006 issue).
"The findings show that PSA levels can be a reliable endpoint measure of prostate cancer treatment efficacy," said Dr. Petrylak, lead investigator. "However, this and other candidate surrogate endpoints must be validated in independent clinical trials of men with prostate cancer."
This study is a follow-up to a landmark phase III trial published in the New England Journal of Medicine (Oct. 7, 2004), by the same Columbia University Medical Center and NewYork-Presbyterian Hospital/Columbia research team, who are members of SWOG, one of the largest cancer clinical trials cooperative groups in the United States. The study found that men with androgen-independent (hormone-refractory) metastatic prostate cancer who were treated with the chemotherapy drug Taxotere® (docetaxel) Injection Concentrate in combination with the drug estramustine survived 20 percent longer than similar patients receiving the standard therapy.
Prostate cancer is the second leading cause of cancer death in men. One in six men will likely develop prostate cancer within their lifetime. The American Cancer Society estimates there were about 232,090 new cases of prostate cancer in the United States in 2005. About 30,350 men will die of the disease this year alone.
The Southwest Oncology Group is one of the largest cancer clinical trials cooperative research groups in the United States. The Group is a network of more than 5,000 physician-researchers located at nearly 550 institutions. In addition to their regular medical practices, Group investigators work together on clinical trials funded by the National Cancer Institute, part of the National Institutes of Health, to prevent and treat cancer in adults. Among the Group's institutions are 17 of the NCI's 61 designated cancer centers. The Group enrolls nearly 7,200 patients each year and has about 120 clinical trials underway at any given time. The Southwest Oncology Group Headquarters Office is at the University of Michigan in Ann Arbor, Mich., the Operations Office is in San Antonio, Texas, and the Statistical Center is in Seattle, Wash. www.swog.org.
Columbia University Medical Center provides international leadership in pre-clinical and clinical research, in medical and health sciences education, and in patient care. The medical center trains future leaders in health care and includes the dedicated work of many physicians, scientists, nurses, dentists, and public health professionals at the College of Physicians & Surgeons, the School of Dental & Oral Surgery, the School of Nursing, the Mailman School of Public Health, the biomedical departments of the Graduate School of Arts and Sciences, and allied research centers and institutions. www.cumc.columbia.edu/newsroom
NewYork-Presbyterian Hospital is the largest not-for-profit, non-sectarian hospital in the country. It provides state-of-the art inpatient, ambulatory and preventive care in all areas of medicine at five major centers: NewYork-Presbyterian Hospital/Columbia University Medical Center, NewYork-Presbyterian Hospital/Weill Cornell Medical Center, Morgan Stanley Children's Hospital of NewYork-Presbyterian, The Allen Pavilion, and the Westchester Division. It consistently ranks as one of the top hospitals in the country in U.S. News & World Report's guide to "America's Best Hospitals." The NewYork-Presbyterian Healthcare System – an affiliation of acute-care and community hospitals, long-term care facilities, ambulatory sites, and specialty institutes –serves one in four patients in the New York metropolitan area. www.nyp.org
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