Obtaining a second opinion could significantly improve the accuracy of breast cancer biopsies, according to a study from the University of Washington.

“The millions of women undergoing breast biopsy each year rely on us for a correct diagnosis,” said Joann Elmore, a professor of general internal medicine at the UW’s School of Medicine and adjunct professor of epidemiology at the School of Public Health. “Our ultimate goal is to improve health and healthcare for these women, which begins with a correct diagnosis.”

Breast biopsy samples are difficult to diagnose, the study noted. Misdiagnosis can lead to under-interpretation resulting in delays and unnecessary treatment, while over-interpretation can result in costly, and potentially unnecessary, therapies like mastectomy and radiation therapy.

Most pathology laboratories require that certain findings are always reviewed by another pathologist for a second opinion. This is particularly common in cases where the initial diagnosis is invasive carcinoma, the most common type of breast cancer.

The study, published online in the BMJ, is the first of its kind to systematically compare different strategies for obtaining second opinions as an approach to reducing diagnostic errors. Researchers examined 12 such strategies to gauge their effectiveness.

The study found all strategies reduced errors in interpretation, except for the strategy limiting second opinions only to cases of invasive cancer. Overall misdiagnosis rates decreased from 24.7 percent to 18.1 percent when all cases received second opinions. However, they did not eliminate diagnostic errors entirely.

Accuracy improved regardless of whether a second opinion was desired or requested by the initial pathologist, the study noted.

“Many pathologists seek second opinions in clinical practice through informal routes,” the researchers wrote. “It might be time for clinical support systems and payment structures to align with and better support clinicians in their current practice.”

To learn about the impact of second-opinion strategies, researchers used a simulation to evaluate interpretations of 240 breast biopsy specimens from 115 pathologists. The specimens included interpretations of benign without atypia, atypia, DCIS and invasive cancer.

Elmore co-authored the study with Anna Tosteson, professor of medicine at Dartmouth College. Donald Weaver, professor of pathology at the University of Vermont, was a senior author.