USC New England Journal Of Medicine Study Urges Caution In Use Of Radiation Therapy
LOS ANGELES, May 5, 1999 - Patients with one of the most common and curable forms of breast cancer may be undergoing radiation therapy unnecessarily, according to a University of Southern California study to be published in the May 13 New England Journal of Medicine.
The study, headed by Melvin J. Silverstein, M.D., medical director of the Harold E. and Henrietta C. Lee Breast Center at the USC/Norris Comprehensive Cancer Center, examines ductal carcinoma in situ (DCIS), a noninvasive breast cancer that has been the subject of a recent heated debate over treatment. Until 1980, DCIS was a relatively uncommon disease, representing only about 1 percent of all newly diagnosed cases of breast cancer. During the past two decades - as mammography has become more widely used and technically better - the number of new cases has increased dramatically.
Today DCIS represents as much as 40 percent of new breast cancer cases diagnosed by mammography, and estimates suggest that approximately 40,000 new cases of DCIS will be diagnosed this year in the U.S. Seventy to 80 percent of these patients are eligible for breast preserving lumpectomy rather than mastectomy. But opinion is currently divided on whether radiation therapy is necessary for all DCIS patients who choose lumpectomy.
In the NEJM article, Silverstein, a surgical oncologist, and colleagues found that radiation therapy does not appear to benefit patients where the margin width - the distance between the boundary of the lesion and the edge of the excised specimen - is 10 millimeters or more.
"Wide margin width makes complete excision more likely," says Silverstein.
"Since DCIS is a noninvasive cancer that does not spread (metastasize), complete
cure the patient. These findings will have important ramifications for
thousands of women with the disease. These data suggest that radi
Contact: Mary Ellen Stumpl or Brenda Maceo
University of Southern California