Predicting Residual Breast Cancer After Neoadjuvant Chemotherapy
Posted: Friday, March 27, 2020
Results from a multi-institutional study suggest that a standardized protocol using image-guided vacuum-assisted biopsy in patients with breast cancer may allow for a reliable prediction of residual disease and pathologic complete response after neoadjuvant chemotherapy. The research, presented at the 2019 San Antonio Breast Cancer Symposium (Abstract GS5-04) by Henry M. Kuerer, MD, PhD, of The University of Texas MD Anderson Cancer Center, Houston, and colleagues, suggests that exceptional responders to neoadjuvant chemotherapy may be able to avoid surgery.
“The key finding from this multicenter trial illustrates that we must be super selective regarding the specific patient population to study this new paradigm,” shared Dr. Kuerer in an MD Anderson press release. Future additional studies will be designed to de-escalate treatment in exceptional responders to neoadjuvant chemotherapy and explore the safety of eliminating surgery for this patient population.
Researchers analyzed data from 166 women who underwent image-guided biopsies after neoadjuvant chemotherapy. There were 160 patients who had invasive ductal carcinoma, with an average tumor size before treatment of 33.5 mm. The overall pathologic complete response rate was 51.2%
Vacuum-assisted biopsies were performed on 143 patients, and 32 underwent core-cut biopsy. When the image-guided biopsy was representative, the false-negative rate across the whole cohort was 18.7%. Exploratory analysis of the accuracy of vacuum-assisted biopsy in cases with a residual imaging abnormality less than 2 cm and at least 6 representative biopsies taken (n = 76) showed a false-negative rate of 3.2%, a negative predictive value of 97.4%, and an overall accuracy of 89.5%.
A subgroup analysis focused on 66 patients with HER2-positive or triple-negative cancer who are most likely to be exceptional responders and achieve pathologic complete response. In this group, similar accuracy of the technique was reported, with a false-negative rate of 4.2%, a negative predictive value of 97.2%, and an overall accuracy of 87.9%.
Disclosure: For full disclosures of the study authors visit abstractsonline.com.
