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3-D mammography test appears to improve breast cancer detection rate

NEW YORK – Adding a newer test to digital mammograms can increase the detection rate for breast cancer and decrease nerve-racking false alarms, in which suspicious findings lead women to get extra scans that turn out normal, a study finds.

Millions of women will get the newer test, tomosynthesis, this year. The procedure is nearly identical to a routine mammogram, except that in mammography the machine is stationary, but in tomosynthesis it moves around the breast. Sometimes called 3-D mammography, the test takes many X-rays at different angles to create a three-dimensional image of the breast. It was approved in the United States in 2011.

The verdict is still out on the long-term worth of this new technology. The new results are promising but not definitive, according to experts not associated with the study, published Tuesday in the Journal of the American Medical Association. Tomosynthesis has not been around long enough to determine whether it saves lives or misses tumors.

Even so, more and more mammography centers are buying the equipment – which is far more costly than a standard mammography unit – and marketing the test to patients as a more sensitive and accurate type of screening. It has come on the scene at a time when the value of breast cancer screening and the rising costs of health care are increasingly debated.

Some 1,100 of about 13,500 mammography units in the United States perform tomosynthesis, according to Jim Culley, a spokesman for Hologic, the company that makes the only tomosynthesis equipment approved by the Food and Drug Administration. He estimated that more than 6 million U.S. women will undergo tomosynthesis this year.

“It is very much taking hold in the breast-imaging world,” said Dr. Sarah M. Friedewald, the section chief of breast imaging at Advocate Lutheran General Hospital in Park Ridge, Ill., and the first author of the new study.

Recent studies have suggested that the benefits of mammography have been overstated and its potential harms understated, but many health groups still recommend it. More than 38 million mammograms are performed each year in the United States, at a cost of about $8 billion.

The new information on tomosynthesis is “not going to resolve the ongoing discussions about the overall utility of mammography,” said Dr. Barnett S. Kramer, director of the Division of Cancer Prevention at the National Cancer Institute. He added: “In a nutshell, it shows sufficient promise that the thought leaders are interested and so are the people who deal with imaging and screening at the National Cancer Institute.”

Kramer was not part of the study, but the institute helped support it by providing a research grant to one of its authors.

Dr. Etta D. Pisano, a mammography expert and dean of the Medical University of South Carolina, called tomosynthesis “extremely promising.”

But in an editorial with the journal article, Pisano, who was not involved in the study, said it was still not clear whether women should seek it or clinics should adopt it. She said more research was needed. One concern she raised about the study was that it simply looked back at records instead of using the more rigorous method of picking patients at random to compare types of screening.

Hologic, based in Bedford, Mass., paid for the study and had the right to review the journal article before publication but could not change it, the researchers said.

In an interview, Pisano said, “We need to be cautious as we adopt a new technology.”

She said that tomosynthesis units cost about half a million dollars, twice the price of a digital mammography machine, and that her university could not afford one.

“Wealthy communities can afford it,” she said.

Hologic declined to provide pricing information for its equipment.

The tomosynthesis test costs more than digital mammography and not all insurers cover it. Culley said that when coverage is denied, some clinics charge patients $50 or so for the extra test in addition to the usual mammography fee.

Adding tomosynthesis lowered recall rates, sparing some women an experience that many find frightening. With digital mammography alone, for every 1,000 women, 107 were called back for more X-rays, but with tomosynthesis added, the figure was 91.

Companies are expected to introduce tomosynthesis equipment in the U.S.