Comparison of progressed and unresponsive patients with responsive patients at ınterim assessment during breast cancer neoadjuvant chemotherapy

Abstract

Aim: It was aimed to compare the breast cancer patients who were progressed or unresponsive to neoadjuvant chemotherapy with the patients clinically responsive to the treatment at interim radiological assessment. Materials and Methods: Female patients operated in our hospital for breast cancer after neoadjuvant chemotherapy were retrospectively screened. Patients having interim radiological assessment were included in the study. Patients were divided into three groups as responsive, unresponsive (stable) and progressive according to the imaging results. Unresponsive and progressive patients were compared to responsive patients in terms of patient and tumor characteristics. Results: A total of 96 patients were included in the study. According to the interim imaging results, 90.6% of patients (87 patients) had a radiological response to the treatment. Four patients (4.2%) with radiological unresponsiveness and five patients (5.2%) with radiological progression (9 patients in total, 9.4%) were referred to operation. The mean age of the unresponsive patients was found to be statistically higher than the responding patients (60 vs. 49, p=0.035). The tumor grade and Ki-67 index of unresponsive patients were lower than the responsive patients (respectively; 1.5±0.6 vs. 2.4±0.5, p=0.007 and 10±4 vs. 37±22, p=0.003). Although the tumor grade and Ki-67 index were higher in patients who progressed than the responders, they weren’t statistically significant. Unresponsive patients were mostly luminal A (3/4 patients), and progressive patients were mostly triple negative (3/5 patients) molecular subtype. Conclusion: Luminal breast cancers with low proliferation index and grade tend to be insensitive to neoadjuvant chemotherapy. On the other hand, hormone receptor negative tumors with high proliferation index and grade may respond well to neoadjuvant chemotherapy and may also pose a risk for progression. Further clinical studies are needed.