Radiologist’s Ability Influences Reading of Mammograms: Study

Leaving some women open to false positive results or even missed diagnoses, Radiologists reading mammograms miss an average of 2 in every 10 cases of breast cancer, US researchers show.

Used to look for different types of tumors and cysts, Mammography is the process of using low-dose X-rays to examine the human breast.

A proven method to reduce mortality from breast cancer, diagnostic mammography is done when cancer is suspected and when any tumors would presumably be large and easier to spot.

For the study 123 radiologists interpreted nearly 36,000 diagnostic mammography examinations conducted in 72 facilities in Washington, New Hampshire and Colorado from January 1, 1996, through December 31, 2003.

Researchers found that a woman's odds of being diagnosed with accurate results varied widely, mainly depending upon the skill of the radiologist reading the report.

Radiologists who concentrated largely on breast imaging and doctors at academic medical centers were better performers.

While specialists missed on 1 of 5 women who turned out to have cancer, the worst radiologists missed nearly 40 percent of the tumors and misidentified 8.3 percent of their patients as having cancers.

Numerically, the cancer sensitivity – the ability to detect cancer when it's present—ranged from 27 percent to 100 percent, with a median of 79 percent. The false-positive rate—women who got a tentative diagnosis of cancer when they didn't have it—ranged from zero to 16 percent, with a median of 4.3 percent.

Furthermore, the radiologists with the highest detection rates for cancer also tended to have slightly higher false-positive rates, the researchers noted.

"On average, 21 percent of breast cancers were missed and 4.3 percent of women underwent a biopsy even though they didn't have breast cancer," Diana Miglioretti, a researcher at the Group Health Center for Health Studies in Seattle specified.

The study was funded by grants from the National Cancer Institute, Agency for Healthcare Research and Quality and Breast Cancer Surveillance Consortium.

The three-state study led by Seattle's Group Health Cooperative features in the online Tuesday in the Journal of the National Cancer Institute.