Digital mammography that uses computers to detect breast cancer found significantly (up to 28%) more cancers than screen film mammography in women 50 and younger, premenopausal and perimenopausal women, and women with dense breasts, according to results from one of the largest breast cancer screening studies ever performed.
However, the study showed no difference between digital and standard x-ray mammography in detecting breast cancer for the general population of women. More than 1,300 women took part in the trial at the University of Virginia Health System, one of 33 sites in the U.S. and Canada to study the effectiveness of digital mammogram technology.
"It's important for every women to get a quality mammogram. But if you're under 50, premenopausal or know you have dense breast tissue, you should consider having a digital mammogram at your next scheduled screening," said Dr. Jennifer Harvey, a radiologist and head of breast imaging at the UVa Health System and site investigator for the trial at UVa. "However, women should not delay getting a mammogram if only film screen technology is available. Traditional film screen mammograms save lives as well."
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.
UVa has been performing digital mammography as part of research studies since the mid-1990's and for clinical use since 2001. The breast program at UVa currently has three GE digital mammogram machines for patients, two in the Breast Care Center in the West Complex and one at Northridge. A fourth digital machine is expected in mid-October to be housed in UVa's mobile mammography van.
According to the National Cancer Institute, breast cancer is the most common non-skin cancer, and the second leading cause of cancer-related death in women in the United States. An estimated 211,240 women will be diagnosed with breast cancer and an estimated 40,410 women will die of the disease in the U.S. in 2005.
The results of the trial, called DMIST (Digital Mammographic Imaging Screening Trial), are reported in a special online publication of the New England Journal of Medicine. The trial was funded by the NCI and conducted by the American College of Radiology Imaging Network (ACRIN). Starting in October 2001, DMIST enrolled nearly 50,000 women who had no signs of breast cancer. Women in the trial were given both digital and film mammograms. Mammograms were interpreted independently by two different radiologists. Breast cancer status of the participants was determined through breast biopsy or follow-up mammography.
"I am very proud of the accomplishments of the DMIST researchers," said Dr. Bruce Hillman, a professor of radiology at the UVa Health System and chair of ACRIN.
"This landmark trial, along with others currently being conducted by ACRIN, will influence the appropriate care for women everywhere."