Volunteers Sought for Study That May Determine Future of Mammography
Researchers at UCLA's Jonsson Cancer Center are seeking thousands of women for a national study comparing digital mammography to standard mammography for the detection of breast cancer. UCLA is the only Southern California center to offer the study.
UCLA radiologists are working to recruit 2,475 women to participate in the study, called the Digital Mammographic Imaging Screening Trial (DMIST). Nationwide, about 49,500 women will participate in DMIST, which is coordinated by the National Cancer Institute and the American College of Radiology.
"This study is the next step in the digital revolution," said Dr. Lawrence Bassett, a national breast imaging expert, director of the Iris Cantor Breast Imaging Center at the Jonsson Cancer Center and principal investigator for the UCLA arm of the study.
"Digital mammography holds promise to improve earlier detection of breast cancer, but a large study is necessary to see whether digital mammography really is better than or as effective as standard mammography," Bassett said. "Despite some limitations, mammography remains the most effective way to detect breast cancer. It is the only detection method that has been studied in large trials and proven to reduce deaths from breast cancer. So working to improve mammographic images is critical to improving accuracy in breast cancer detection."
Mammography's effectiveness can be limited in women who have very dense breasts, Bassett said. Dense tissue often appears white on a standard mammogram, which is printed out on dark-colored X-ray film. Abnormalities such as cancer or benign calcifications also appear white, so without a contrasting background, radiologists may have difficulty seeing and characterizing such abnormalities.
Digital mammography uses computers and specially designed detectors to produce a digital image of the breast that can be displayed and manipulated -- enlarged, magnified, lightened or darkened -- on high-resolution monitors. Digital mammograms also can be printed out on X-ray film
for easier comparison with standard mammography. Unlike standard mammography, the image produced by a digital mammogram can be lightened or darkened prior to being printed on film.
"One possible advantage of digital mammography is that it may be more effective in detecting cancers in women with dense breasts because the digital mammogram images have a wider contrast range than images on standard mammograms," Bassett said. "With standard mammography, radiologists have a more limited ability to spot abnormalities in dense breast tissue or recognize tumors with subtle or faint borders."
To qualify for DMIST, volunteers must not have a history of breast cancer surgery, have breast implants, be pregnant or have a pre-existing breast lump or nipple discharge. Upon enrolling in the study, participants must be due for an annual screening mammogram. Participants also must agree to undergo a standard mammogram and a digital mammogram one year later at UCLA or another study site.
During one appointment, study participants will receive a standard mammogram and a digital mammogram. The order in which they receive the mammograms will be determined by chance through a computerized randomization process. A total of eight films, or views, will be taken, as each mammogram will involve two views per breast. For women with large breasts, additional digital and standard mammograms may be taken to ensure that all portions of the breast have been imaged.
"Standard and digital mammography involve the same kinds of positioning and amount of breast compression, so participants should not expect to feel a difference between the two procedures," Bassett said.
Two UCLA radiologists will review and interpret each study participant's mammograms. At the American College of Radiology in Philadelphia, Pa., two more radiologists with expertise in breast imaging also will review and interpret each participant's mammograms.
"One possible benefit of the study is that screening mammograms, which are used to monitor healthy breasts for abnormalities, usually are read by one or two radiologists. But in DMIST, the mammograms will be reviewed by four radiologists. So participants should feel confident that their mammograms will be reviewed with heightened scrutiny," Bassett said.
Bassett expects study recruitment to take about two years.
Study participants will receive minimal amounts of radiation from standard mammography. Digital mammography generates the same amount of radiation as standard mammograms, but digital mammography may emit slightly more radiation if a woman's breast tissue is very dense. As with all mammograms, there is a risk of false positives--breast abnormalities that look worrisome on a screening mammogram and may require further work-up with additional imaging procedures.
Women interested in volunteering for or obtaining more information about the study can call (310) 794-1702 or use the toll-free Jonsson Cancer Center clinical trials hotline at 888-798-0719.
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