Evaluation of the relationship of treatment response rates and clinical and pathological factors in local advanced breast cancer patients requesting neoadjuvan treatment

Evaluation of the relationship of treatment response rates and clinical and pathological factors in local advanced breast cancer patients requesting neoadjuvan treatment INTRODUCTION AND AIM: In this study, a retrospective review of the relationship between treatment response rates and prognostic and predictive clinicopathological factors in locally advanced breast cancer given neoadjuvant chemotherapy; It was aimed to examine the relationship between pathological tumor response and other histopathological parameters after neoadjuvant chemotherapy and to show the effects of these factors on objective response rates. METHODS: Followed by Sakarya University Training and Research Hospital Medical Oncology Clinic between January 2014 and May 2022; 205 patients who underwent breast and axilla biopsy, diagnosed with locally advanced breast cancer, and subsequently underwent surgery were evaluated. Outpatient follow-up files, laboratory results, radiological imaging, pathology reports, and chemotherapy protocol files of the patients were reviewed retrospectively. Parameters such as age, menopausal status, clinical and pathological stage, tumor diameter, histological type, hormone and HER-2 receptors, molecular subtypes were examined. RESULTS: When pathological response rates of molecular subtypes were analyzed, complete response rates; 10,5% for luminal-A, 39,7% for luminal-B HER-2 positive type, 29,6% for luminal-B HER-2 negative type, 73,7% for HER-2 rich type and triple negative It was determined as 41,9% for the type (p<0,001). When the effect of molecular subtypes on providing objective response is evaluated; When the luminal-A group is taken as reference; luminal-B HER-2 negative type (OR:2,93 95%CI: 1,23-6,98, p=0,015), luminal-B HER-2 positive type (OR: 6,93 95%CI: 2,75 -17,46, p<0,001), HER-2 rich type (OR: 26,40 95%CI:3,18-219,48, p=0,002) and triple negative type (OR: 5,03 95%CI:1,73-14,62, p=0,003), all groups were found to be significantly more effective on objective response. CONCLUSION: Response of molecular subtypes to neoadjuvant therapy was found to be different. Especially in triple negative subtypes and HER-2(+) subtypes, response rates to neoadjuvant therapy were found to be much better in accordance with the literature. Identifying prognostic factors more accurately before and after neoadjuvant therapy and confirming it with studies that will include a larger number of patients and show a more homogeneous distribution; In these patients, the factors that can predict pathological complete responsiveness will be revealed more accurately. Keywords: Breast cancer, molecular subtype, neoadjuvant chemotherapy.