Histomorphological Changes and Pathological Response Following Neoadjuvant Chemotherapy in Breast Carcinoma: A Cross-Sectional Study

Background: Neoadjuvant chemotherapy (NACT) is widely used in the management of locally advanced breast carcinoma to downstage tumors and improve surgical outcomes. Histopathological evaluation of post-NACT specimens and assessing pathological response using the Miller–Payne grading system provides critical information regarding therapeutic response and prognosis.Methods: This cross-sectional study included 50 patients with biopsy-proven breast carcinoma who received two or more cycles of neoadjuvant chemotherapy followed by surgical excision. Post-therapy specimens were examined for nuclear, stromal, and inflammatory changes using routine hematoxylin and eosin staining. Tumor regression was graded according to the Miller–Payne system. Statistical analysis was performed using SPSS version 20, with p < 0.05 considered statistically significant. Result: The mean age of patients was 52.78 ± 10.43 years. Invasive ductal carcinoma, no special type, was the most common histological subtype (88%). A significant reduction in tumor size was observed following neoadjuvant chemotherapy, with mean tumor size decreasing from 4.87 ± 1.14 cm pre-NACT to 1.94 ± 1.16 cm post-NACT (p < 0.0001). Histomorphological changes included nuclear alterations in 60% of cases, stromal fibrosis or sclerosis in 52%, tumor necrosis in 64%, and inflammatory infiltrate in 90%. Pathological complete response was achieved in 14% of cases, while partial response was observed in 64%.Conclusion: Histopathological evaluation remains the most reliable method for assessing response to neoadjuvant chemotherapy in breast carcinoma. Therapy-induced nuclear and stromal changes correlate with pathological response and have important prognostic implications.