(RxWiki News) A mammogram can be a useful tool for finding breast cancer in women, but sometimes getting a standard mammogram may not be enough. A new study suggests that 3-D mammography may detect cancer more often than a mammogram alone.
Past research has shown that women with dense breasts were more likely to develop breast cancer. However, mammogram machines have some difficulty detecting cancer in dense breasts.
The authors of this new study found that, for women with dense breasts, adding 3-D images to a normal mammogram identified more cases of breast cancer.
This research was conducted by Per Skaane, MD, PhD, of the Department of Radiology at Oslo University Hospital in Norway, and colleagues.
"Our results show that implementation of tomosynthesis might indicate a new era in breast cancer screening," Dr. Skaane said in a press release.
Dr. Skaane and co-authors studied tomosynthesis — also called 3-D mammography. Tomosynthesis creates a 3-D picture of the breast using X-rays.
Dr. Skaane said that tomosynthesis should be considered an improvement to the current mammogram used in most hospitals today.
The US Food and Drug Administration has approved tomosynthesis, but it is not yet considered the standard of care for breast cancer screening.
These researchers studied the mammograms of 25,547 women between the ages of 50 and 69. They compared cancer detection using full-field digital mammography (FFDM) versus FFDM plus tomosynthesis. FFDM is a mammography unit that captures an electronic picture of the breast in digital format.
The authors measured breast density using the American College of Radiology's Breast Imaging-Reporting and Data System (BI-RADS). The BI-RADS scale runs from 1 to 4, with 1 being the least dense and 4 being most dense.
Dense breasts have less fatty tissue and more glandular tissue than breasts that aren't dense. Glandular tissue makes and drains breast milk. One way to measure breast density is the thickness of tissue on a mammogram.
Standard mammograms often have a hard time detecting breast cancer in dense breasts, Dr. Skaane and team noted. Breast cancer tumors (which appear white) are easier to see on a mammogram when they're surrounded by fatty tissue (which appears dark).
These researchers found a combined total of 257 malignancies in patients using both FFDM by itself and FFDM plus tomosynthesis.
A tumor can be benign (not dangerous to health) or malignant (could be dangerous).
Of the women with malignancies, 105 were in the BI-RADS density 2 group and 110 were in density 3 group, noted study authors.
Women in the BI-RADS density 2 group had a few small pockets of glandular tissue within their breasts. Women in the BI-RADS density 3 group had more areas of glandular tissue throughout the entire breast. These areas can make it hard to see small cancer masses on a standard mammogram machine.
Dr. Skaane and team indicated that, of the 257 patients who had malignancies, 211 (82 percent) of the cancer masses were detected using FFDM plus tomosynthesis. These researchers identified 63 percent of the cancer masses using only FFDM.
"Our findings are extremely promising, showing an overall relative increase in the cancer detection rate of about 30 percent," Dr. Skaane said.
Dr. Skaane and colleagues noted that 3-D mammography found a total of 80 percent of the malignancies in women with dense breasts — versus 59 percent using FFDM alone.
This study was presented Dec. 2 at the annual meeting of the Radiological Society of North America in Chicago.
The authors disclosed no funding sources or conflicts of interest.
