Abnormal cells are misidentified in one-fourth of cases, research suggests
WebMD News from HealthDay
By Dennis Thompson
TUESDAY, March 17, 2015 (HealthDay News) -- As many as one of every four breast tissue biopsies tested for cancer may have been incorrectly diagnosed by pathologists taking part in a study to test their skills.
The pathologists did well at identifying invasive breast cancer, but they struggled with spotting whether abnormal cells in a tissue sample might increase a woman's future cancer risk. This may mean that some women are being treated too aggressively, the researchers noted.
Overall, individual pathologists peering at breast cells through a microscope disagreed about 25 percent of the time with an expert pathology panel's interpretation of the same glass slides.
These bad calls could have serious consequences for some of the 1.6 million American women who undergo a breast biopsy each year, the researchers added.
The accurate diagnosis of cancer hinges on pathologists' microscopic examination of tissue samples from patients, explained study author Dr. Joann Elmore, a professor of medicine at the University of Washington in Seattle.
Women with a wrongly interpreted biopsy might undergo unnecessary surgery or radiation therapy, receive unwarranted MRIs or mammograms, or spend many anxious years fretting that they are at increased risk for cancer when they actually are not, Elmore said.
In this study, pathologists displayed remarkable accuracy in diagnosing samples taken from women with invasive breast cancer, which can be fatal unless treated promptly, Elmore said.
"It's reassuring there was near-perfect agreement on the diagnosis of invasive breast cancer," she said. Nearly one-quarter of the breast biopsies taken annually in the United States are diagnosed as invasive breast cancer.
However, pathologists had trouble analyzing breast biopsies that contained abnormal or cancerous cells which increase a woman's future risk of invasive breast cancer, the study found.
Individual pathologists disagreed with the expert panel in about one out of five cases of ductal carcinoma in situ, or DCIS, Elmore said.
DCIS is early, noninvasive breast cancer, featuring cancerous cells that are present in the milk ducts but have not spread to the surrounding breast tissue, according to the U.S. National Cancer Institute.
source : Study Questions Accuracy of Many Breast Cancer Biopsies