How Reliable Is Tumor Bed Biopsy in Predicting Treatment Response in Breast Cancer?

By: Justine Landin, PhD
Posted: Wednesday, December 27, 2023

Tumor bed biopsy may not be an accurate predictor of select clinical outcomes for responders with newly diagnosed nonmetastatic breast cancer, according to Sudha Murthy, MD, of Basavatarakam Indo American Cancer Hospital & Research Institute, Hyderabad, India, and colleagues. In fact, ultrasound-guided core needle biopsy did not appear to be a reliable predictor of pathologic complete response for these patients. The findings of this validation study were published in JCO Global Oncology.

“The study underscores the importance of further research on omitting surgery in the breast after neoadjuvant chemotherapy, and future protocols should explore alternative image-guided biopsy methods for sampling the postchemotherapy tumor bed,” stated the study investigators.

Patients with newly diagnosed nonmetastatic breast cancer who had a complete or near-complete response confirmed by mammogram and ultrasound to neoadjuvant chemotherapy were enrolled (n = 65). Most patients had node-positive (94%), hormone receptor (HR)-negative (60%), tumor stage 1 or 2 (75%) breast cancer. A minimum of four ultrasound-guided core biopsies of the tumor bed using a 14G needle were performed and compared with postsurgical histopathologic reports. Absence of residual invasive or in situ breast and axillary tissue was considered evidence of a pathologic complete response.

Across the entire cohort, a pathologic complete response was observed in 27 women (41.5%). Among these patients, all except one exhibited a concordant complete response in the axilla. For patients with HR-negative cancer, 21 women had a pathologic complete response (53.8%). The false-negative rate of predicting pathologic complete response through core needle biopsy was 42.1% for all patients (95% complete response [CI] = 26.3%–59.2%) and 44.4% for the HR-negative subgroup (95% CI = 21.5%–69.2%). No differences were observed between patients who achieved a pathologic complete response and those who did not based on age (P = .56), tumor stage (P = .31), nodal stage (P = .76), or grade (P = .31).

Disclosure: The study authors reported no conflicts of interest.

JCO Global Oncology