A better mammogram? Huge study putting 3-D scans to the test

WASHINGTON (AP) — A better mammogram? Increasingly women are asked if they want a 3-D mammogram instead of the regular X-ray — and now U.S. health officials are starting a huge study to tell if the newer, sometimes pricier choice really improves screening for breast cancer.

It's the latest dilemma in a field that already vexes women with conflicting guidelines on when to get checked: Starting at age 40, 45 or 50? Annually or every other year?

The issue: Mammograms can save lives if they catch aggressive breast cancers early. But they also can harm through frequent false alarms and by spotting tumors that grow so slowly they never would have posed a threat — overdiagnosis that means some women undergo unneeded treatment.