New tests that measure water, oxygen, and other breast-tissue properties could be more effective than mammograms in diagnosing breast cancer, scientists said Monday. Researchers at Dartmouth Medical School used several types of electromagnetic waves to gauge how normal breast tissue absorbed or scattered light. By first measuring healthy breasts, the new techniques can eventually help researchers better understand and detect changes that could signal cancer, said the study's lead author, Steven Poplack. "It's very important to know what normal is before you can begin to characterize what abnormal is," Poplack said.
The three types of energy waves tested included infrared light, microwaves, and low-level electrical currents, according to the study published in the May issue of the journal Radiology. Mammograms, the standard test for breast abnormalities, use X-rays to take pictures of breast tissue. Experts say mammograms do not work as well on dense breasts, which can make it easy for doctors to miss very early-stage cancer in some women. Mammograms can also fail to distinguish between cancerous tumors and other thick matter, raising the risk of false positives, they say. The new techniques measure normal-tissue levels of oxygen and hemoglobin, which carries oxygen in the blood. Breast cancer tissue is "more active," Poplack said, and uses more oxygen and blood to survive. Scientists also measured cell membrane structure and the tissue's ability to conduct and store electrical charges. Poplack's team used the alternative technologies on 23 white women, ages 40 to 79, who had a history of normal mammograms, the study said.
The five-year, $7 million study, funded by the National Institutes of Health's National Cancer Institute, is part of a larger effort to find alternative ways to create images of the breast, principal investigator Keith Paulsen said. The researchers, who are seeking another $10 million in National Cancer Institute grants, are working on a second study using the new techniques on women who have had abnormal mammograms. Poplack said another five years of intensive study is needed before broader studies can be conducted with more women, including those of different races. Commercial versions of the tests are at least 10 years away, he said. (Reuters)