Researchers are looking to recruit more than 6,300 Canadian women in the first large North American study of its kind to determine whether 3D mammography is more effective at detecting breast cancer than the 2D technology currently used.

The Tomosynthesis Mammography Imaging Screening Trial (TMIST) will be conducted in Vancouver, Toronto and Ottawa, as well as multiple locations in the United States.

Researchers want to find out whether combining 3D mammograms, known as digital tomosynthesis technology, with 2D mammograms is more effective at breast cancer screening than 2D technology alone.

The 3D mammograms take multiple images that are layered to create a “richer and clearer” picture of the breast, which may help detect cancer hidden in the surrounding breast tissue. 

Previous studies have suggested that the 3D technology can detect up to 40 per cent more breast cancers than 2D mammography, said Dr. Jean Seely, the lead investigator at the Ottawa Hospital Breast Health Centre.

“That’s a huge impact,” she told CTV Ottawa.

Dr. Seely also said that 2D imaging can miss about 15 per cent of cancers or give women false positives.

For every 100 women who are called back for more tests after a 2D mammogram detects something suspicious, more than 90 of them will have a normal finding or a benign growth.

“This high number of initial false positives creates stress for women and may lead to decreased screening use, with a potential greater loss of lives from undetected cancer,” researchers said in a news release.

With the new study, doctors are hoping to “detect the cancers that are aggressive (and) potentially lethal at an earlier stage,” Dr. Seely said.  She and her colleagues are hoping to recruit 2,000 women from the Ottawa area as part of the larger study.

Elaine Finley is one of those recruits. She’s already had her 3D mammogram, which detected a very small, suspicious lump. 

Finley, who is now awaiting the results of a biopsy, told CTV Ottawa she’s not worried. 

“It is small, about 7 millimetres,” she said.

Women who wish to participate at one of the locations in Vancouver, Toronto or Ottawa need to be referred by their doctor. To join the study, women must be 40 or older, already scheduled for a screening mammogram, have no symptoms or history of breast cancer and no breast implants.

More information about the study and eligibility criteria is available here.

With a report from CTV Ottawa’s Joanne Schnurr