Pathology of Breast Carcinomas After Neoadjuvant Chemotherapy: An Overview With Recommendations on Specimen Processing and Reporting

Abstract

Abstract Context.—Currently, more women are being treated with chemotherapy or hormonal agents before surgery (neoadjuvant chemoendocrine therapy) for earlier-stage operable breast carcinoma. The pathologic examination of these specimens can be quite challenging. Objective.—To give an overview of (1) pathologic changes that occur during treatment, (2) systems for evaluating response to treatment, and (3) recommendations for pathologic examination and reporting of such cases. Data Sources.—The recommendations are based on the review of selected literature on breast carcinoma after neoadjuvant therapy and the authors' personal experience with the clinical and pathologic characteristics of cases from each of the authors' own institutions. Conclusions.—Pathologists play a key role in the evaluation of pathologic response, which is extremely important as a prognostic factor for individual patients, as a short-term endpoint for clinical trials, and as an adjunct for research studies. Therefore, surgical pathologists must be familiar with the gross examination, sampling, and reporting of breast carcinomas after neoadjuvant therapy.