Pathological Assessment of Response to Neoadjuvant Chemotherapy among Carcinoma Breast Patients in a Tertiary Level Hospital

Background: The role of the pathologist reporting a case of post-chemotherapy carcinoma breast involves not just looking for residual carcinoma, but also classifying the patient into a response category, based on histological findings, and thus, analyzing the efficacy of treatment. Therapy related changes are well described in carcinoma breast. This study aims at classifying post-chemotherapy specimens based on response to chemotherapy according to the National Surgical Adjuvant Breast and Bowel Project (NSABP) B-18 system and also identifying important associations between morphology, lymph node metastases and hormone receptor status with response. Methods: The study classified thirty-one cases of carcinoma breast who had undergone neoadjuvant chemotherapy in our institution into three categories based on the NSABP B18 system, and analyzed the association of changes in morphology, hormone receptor status and metastases to lymph nodes with presence or absence of response. Results: The commonest response category was partial response (pPR) (17 cases), followed by pathological non-response (pNR) (11 cases) and pathological complete response (pCR) (3 cases). Statistically significant associations were found between presence of residual mass on gross assessment and presence of lymph node metastases with a poor response to treatment. Histopathological features and change in hormone receptor status did not show a significant association with response. Conclusion: The majority of patients showed a partial response to therapy. Presence of a residual mass and presence of metastases to lymph nodes signified poor response.