Comparison of pathological parameters, hormone receptor, CerbB2 and Ki67 profile before and after neoadjuvant chemotherapy in breast cancer

Aim: Breast cancer is the most common type of cancer and the most frequent cause of death in women around the world. Different treatments are applied to patients depending on the histological subtype of the tumor, hormone receptor, CerbB2, Ki67 status and stage of the tumor. Neoadjuvant chemotherapy (NAC), has become an increasingly preferred treatment method. In our study, we compared pathological parameters, hormone receptor, CerbB2 and Ki67 profiles before and after NAC in patients with invasive breast carcinoma who underwent NAC, and compared the two groups. It is aimed to determine an additional parameter that can help in the choice of treatment, dose, and prediction of the patient's prognosis. Materials and Methods: In the Department of Medical Pathology, Cerrahpaşa Faculty of Medicine, between 2016 and 2023, cases reporting breast biopsy before chemotherapy and surgery material after chemotherapy were screened. 174 patients diagnosed with primary breast cancer, whose histological grade, immunohistochemical estrogen receptor (ER), progesteron receptor (PR), CerbB2 and Ki67 data were available before and after chemotherapy, were included in the study. Results: It was seen that cases with a higher histological grade before NAC had a higher response rate to NAC. In the comparison before and after NAC, it was observed that PR showed a significant decrease. In addition, when the cases with a CerbB2 score of 3+ before NAC and those with a score of 2+ and HER2 amplification detected by SISH were compared with each other, it was determined that patients with a score of 3+ at the beginning responded better to NAC. Conclusion: When deciding on NAC, detailed examination of histopathological parameters and molecular subgroups at the stage when the patient is first diagnosed contains important information in terms of predicting the NAC decision, treatment dose and prognosis of the patient at the first diagnosis stage and will contribute greatly to planning personal treatment. has been considered.