Breast Biopsies: What Women Need to Know

A 2015 study out of the University of Washington School of Medicine raised questions about the accuracy of breast biopsy results – particularly those results that fall somewhere between normal and a breast cancer diagnosis. Here’s what women need to know.

Each year about 1.6 million U.S. women have breast biopsies to clarify questions that arise from an abnormal mammogram or breast ultrasound. Biopsies involve removing a small piece of tissue to be evaluated in a laboratory by a doctor specializing in pathology.

The Premise of the Study

In the seven-year University of Washington School of Medicine study, a panel of three recognized expert pathologists looked at biopsy slides from 240 women. The slides were then sent to 115 pathologists around the country who routinely read breast biopsies to compare the findings.

The results: When it came to identifying invasive cancer, or cancer growing into nearby healthy tissue, the outside pathologists and panel agreed on the diagnoses 97 percent of the time. Benign or non-cancerous results had an 87 percent rate of agreement. The agreement was less consistent for diagnoses like ductal carcinoma in situ (DCIS) and atypia that fall in the middle, being neither cancerous nor benign. Because of this, researchers advised women with these diagnoses seek a second opinion on their biopsy results.

A Built-in "Second Opinion"

At Penn Medicine Lancaster General Health, pathologists provide additional levels of expertise absent from the study, building in an automatic “second opinion.” All breast core biopsies are independently interpreted by two pathologists. And, two pathologists with special interest and expertise in breast pathology serve as referees for difficult cases.

The Bottom Line

Media coverage of this study undoubtedly raises anxiety among women undergoing breast biopsies.

However, it is important to keep in mind:

• The study confirms that the majority of breast biopsy diagnoses are accurate.
• Biopsy is still the recommended means of diagnosing abnormalities that appear in mammograms and breast ultrasounds.
• Although atypia and DCIS increase a woman’s risk for developing breast cancer, there is time for thoughtful discussion with your doctor. This will allow you to gain a clear understanding of your biopsy results and the testing practices involved, and determine best course of action for you.