Evaluation of Histomorphological Changes in Post-Neoadjuvant Chemotherapy MRM Specimens – A Tertiary Care Centre Study

Abstract

Background: Globally, Breast cancer is the commonest malignancy among women. Neoadjuvant chemotherapy (NACT) is the treatment of choice for patients with locally advanced breast cancer. Pathological evaluation of tumor size remains the gold standard for evaluation of residual tumor after chemotherapy.1, 2 The aim of study was to evaluate histomorphological changes in the post-NACT MRM biopsies and to assess the response to chemotherapy. Method: The study was carried out over a period of one year in 30 patients of breast cancer who received neoadjuvant chemotherapy and underwent MRM. The pathological tumor response was evaluated. Observations: Mean age of presentation was 50.13 years and mean clinical size was 3.86 cm. Post MRM, residual tumor was found in 22 cases. The mean residual tumor size was 2.53 cm. Complete Pathological Response (pCR) was observed in 8 patients, partial response (pPR) developed in 19 patients and 3 patients elicited no response (pNR). The major observation was overall decrease in cellularity along with significant nuclear and stromal alterations. The common stromal changes observed was necrosis (n=24), fibrosis (n=22), desmoplasia (n=20), hyalinization of vessels (n=18) and chronic inflammatory infiltrates. Nuclear changes (n=14) and cytoplasmic vacuolations (n=11) were also observed. Presence of older age group, larger tumor size, DCIS, LVI and necrosis prior to chemotherapy indicated a poor response to treatment. Conclusion: Each patient responds differently to the NACT based on numerous factors like age, tumor size and tumor morphology. Hence, the pathologists must be aware of the vast array of histomorphological changes seen in breast post-NACT. Keywords: Breast cancer, Neo­Adjuvant Chemotherapy (NACT), Pathological response, Histomorphology, Modified radical mastectomy (MRM)