Response to neoadjuvant chemotherapy in locally advanced breast cancers in association with different clinicopathological parameters

Introduction: Breast cancer being a multifactorial disorder outcome depends on various clinicopathological and molecular factors. Neoadjuvant chemotherapy (NACT) is increasingly used before surgery to obtain pathological complete response (pCR) as it is associated with increase event-free survival and overall survival. Aim: The aim of this study is to evaluate the response to NACT in locally advanced breast cancer (LABC) in association with various clinicopathological factors in a tertiary care setting. Materials and Methods: LABC patients (clinical Stage IIB and III) who underwent either modified radical mastectomy or breast conservative surgery after NACT treatment in a 1-year period were retrospectively reviewed for the clinical and pathological response. Effect of clinicopathological and molecular factors on treatment response were evaluated. pCR was evaluated on final histopathology. Results: Fifty LABC patients fulfilled the study criteria and were reviewed. pCR was present in 6 (12%) cases. All the pCR cases were invasive ductal carcinoma. A statistically significant association between the presence of tumor necrosis in initial biopsy and pCR to NACT was observed (P = 0.024) with a high negative predictive value of 94%. All the 11 patients (100%) with positive lymphovascular emboli (LVE) on initial biopsy did not show pCR. Four out of 6 pCR cases had preclinical tumor size ≤5 cm. Ductal carcinoma in situ (DCIS) was present in 15 cases and only 1 pCR patient had the presence of DCIS. Conclusion: Preclinical tumor size, histopathological tumor type, DCIS, and presence of tumor necrosis and LVE on initial core biopsy are some of the notable factors for pCR among LABC patients who received NACT.