By Kyung M. Song
Seattle Times health reporter
A new three-state study led by Seattle's Group Health Cooperative shows that even the most skilled radiologists fail to detect 20 percent of breast-cancer cases in diagnostic mammograms — which are done when cancer is suspected and when any tumors would presumably be larger and easier to spot.
The findings add weight to concerns about relying on a mammogram, which experts have long said was an imprecise tool for detecting breast cancer. And the research shows that women shouldn't automatically accept a mammogram result — negative or positive — as the final word.
Researchers examined nearly 36,000 mammograms read by 123 radiologists and found that a woman's odds of getting accurate results vary widely depending on who is doing the reading. The worst radiologists missed nearly 40 percent of the tumors and misidentified 8.3 percent of their patients as having nonexistent cancers.
The top performers tended to be doctors at academic medical centers and those who specialized in breast imaging. But even then, the cancer went undetected in one of five women who turned out to have cancer, while 2.6 percent had false-positive results.
The study appeared online Tuesday in the Journal of the National Cancer Institute. ...