Evaluation of histomorphological changes in breast cancer following neoadjuvant therapy at a tertiary care centre, Jharkhand

Breast cancer remains a major cause of cancer-related mortality among women worldwide, with treatment response prediction posing a persistent challenge. Neoadjuvant therapy (NAT) offers tumor downstaging and assessment of histopathological response. In this prospective study of 125 patients, NAT led to a significant reduction in tumor cellularity (82.4% ± 12.3% to 31.7% ± 18.9%, p < 0.001) and increased fibrosis (15.2% ± 8.7% to 48.6% ± 15.4%, p < 0.001). Pathological complete response (pCR) occurred in 32% of patients, with higher rates in triple-negative (42.1%) and HER2-positive (38.5%) subtypes. High post-NAT tumor-infiltrating lymphocytes correlated strongly with pCR (r = 0.67, p < 0.001). Thus, we show that NAT induces significant histomorphological changes, which can serve as key prognostic indicators for therapeutic response and patient outcomes.