Digital mammography trial results announced

Preliminary results from a large, clinical trial of digital vs. film mammography show no difference in detecting breast cancer for the general population of women in the trial. However, those women with dense breasts, who are pre- or perimenopausal (women who had a last menstrual period within 12 months of their mammograms), or who are younger than age 50 may benefit from having a digital rather than a film mammogram. The results were reported September 16, 2005 in a special online publication of the New England Journal of Medicine* and at a meeting of the American College of Radiology Imaging Network (ACRIN) in Pentagon City, Va.

The trial, sponsored by the National Cancer Institute (NCI), part of the National Institutes of Health, was conducted by a network of researchers led by ACRIN. "These results will give clinicians better guidance and greater choice in deciding which women would benefit most from various forms of mammography," said senior author, Etta Pisano, M.D., University of North Carolina at Chapel Hill.

Secondary goals measuring the relative cost-effectiveness of both digital and film technologies, and the effect on participant quality of life due to the expected reduction of false positives are still being assessed and will be reported at a later date.

"This digital mammography study demonstrates how new technologies are expanding our ability to detect breast cancer earlier in more women. The study corroborates NCI’s commitment to exploring advanced technologies in a wide range of clinical applications and the critical role they can play in making cancer a manageable disease," said NCI Director Andrew C. von Eschenbach, M.D.

Starting in October 2001, the Digital Mammographic Imaging Screening Trial (DMIST) enrolled 49,528 women who had no signs of breast cancer at 33 sites in the United States and Canada. Women in the trial were given both digital and film examinations. Examinations were interpreted independently by two different radiologists. Breast cancer status was determined through available breast biopsy information within 15 months of study entry or through follow-up mammography ten months or later after study entry.

Digital mammography takes an electronic image of the breast and stores it directly in a computer, allowing the recorded data to be enhanced, magnified, or manipulated for further evaluation. The electronic image also can be printed on film. Film mammography units use film to both capture and display the image. The sensitivity of film mammography is somewhat limited in women with dense breasts, a population at higher risk for breast cancer.

General Electric Medical Systems, Fuji Medical Systems, Fischer Imaging, and Hologic digital mammography systems were tested in the trial. Of these, all except for the Fuji system are already approved by the U.S. Food and Drug Administration and are available for clinical use in the United States.

An estimated 211,240 women will be diagnosed with breast cancer in the U.S. this year, making it the most commonly diagnosed cancer in women. An estimated 40,410 women will die of the disease this year in the United States.

* Pisano E, Gatsonis C, Hendrick E, Yaffe M, Baum J, Acharyya S, Conant E, Fajardo L, Bassett L, D’Orsi C, Jong R, and Rebner M. Diagnostic Performance of Digital versus Film Mammography for Breast Cancer Screening – The Results of the American College of Radiology Imaging Network (ACRIN) Digital Mammographic Imaging Screening Trial (DMIST). NEJM, published online September 16, 2005 and in print on October 27, 2005.