Breast Cancer Screening Trial Shows Digital Mammogram Benefits

However,the trial, conducted by the American College of Radiology ImagingNetwork (ACRIN) in conjunction with the Center for Statistical Sciencesat Brown Medical School, showed no difference between digital and filmmammography in detecting breast cancer for the general population ofwomen. The results are reported today in a special online publicationof the New England Journal of Medicine and presented at ACRIN’s fallmeeting in Arlington, Va.

With 49,528 women enrolled at 33clinical sites, including Rhode Island Hospital, the trial is one ofthe largest breast cancer screening studies ever performed. Brown’sCenter for Statistical Sciences developed the study’s statisticaldesign and analyzed the results.

“The data show that digitalmammography is, on average, as good at detecting breast cancer as filmmammography – and in some important subgroups of women, digitalperforms even better,” said Constantine Gatsonis, network statisticianfor ACRIN, professor of community health and applied mathematics atBrown, and an author of the New England Journal article.

Becauseof its size and rigor, Gatsonis said, the study provides some of thebest data gathered on the diagnostic accuracy of mammograms. “Neitherfilm nor digital mammography is able to catch every cancer,” Gatsonissaid. “So this study data can be used to develop and improvemammography in the coming years. And that is good news for women’shealth.”

The primary aim of the trial, dubbed the DigitalMammographic Imaging Screening Trial (DMIST), was to compare thediagnostic performance of digital and film mammography.

Womenenrolled in the trial had no signs of breast cancer. Volunteers of allages – the median age was 54 – took part. Each woman was given bothdigital and film screenings. Then they were randomized so that half hadthe digital exam first, the other half had the film exam first. Twodifferent radiologists independently interpreted the mammograms.

Doctorsdetermined participants’ breast cancer status through follow-upmammography or available biopsy results. Biopsy information wasavailable within 15 months of study entry. Mammograms were taken 10months or later after study entry.

Barbara Schepps, M.D., oversawDMIST at Rhode Island Hospital (RIH), a major trauma center forsoutheastern New England and the largest teaching hospital of BrownMedical School. The site enrolled 642 participants.

A radiologistand director of the Anne C. Pappas Center for Breast Imaging at RIH,Schepps said, “With this new information, we are going to strive toconvert all our units to digital as soon as possible. While the studydoesn’t show that digital mammography benefits all women, it clearlymakes a difference for younger women, a population that is known to bedifficult to examine because they tend to have denser breasts.

“Theimportant message is that all women get screened annually – whetherwith digital or conventional mammography,” said Schepps, a clinicalprofessor at Brown Medical School.

The study’s principalinvestigator and senior author of the article, is Etta Pisano, M.D.,the Kenan Professor of Radiology and Biomedical Engineering at theUniversity of North Carolina–Chapel Hill. Pisano directs the BiomedicalResearch Imaging Center at the UNC and is a member of theUNC-Lineberger Comprehensive Cancer Center.

The National CancerInstitute funded DMIST. According to institute statistics, breastcancer is the most common non-skin cancer and the second leading causeof cancer-related death among women in the United States. An estimated211,240 women will be diagnosed with breast cancer and an estimated40,410 women will die of the disease in the United States in 2005.

AtBrown's Center for Statistical Sciences, faculty, students, and staffdevelop bio-statistical methodology and conduct interdisciplinaryresearch in medicine, public health and the biosciences. The Center isknown for its expertise in diagnostic test evaluation and is home tothe Biostatistics Center of ACRIN, a National CancerInstitute-sponsored clinical trials cooperative group made up ofinvestigators from more than 100 academic and community-basedfacilities in the United States, as well as several abroad.

Foundedin 1863, Rhode Island Hospital is a private, not-for-profit hospitaland is the largest teaching hospital of Brown Medical School. A majortrauma center for southeastern New England, the hospital is dedicatedto being on the cutting edge of medicine and research. Rhode IslandHospital ranks 13th among independent hospitals which receive fundingfrom the National Institutes of Health, with research awards of morethan $27 million annually. Many of its physicians are recognized asleaders in their respective fields of cancer, cardiology, diabetes,orthopedics and minimally invasive surgery. Rhode Island Hospital is afounding member of the Lifespan health system.