Evaluation of the effect of treatment response to disease and overall survival and disease free survival in patients with breast cancer treated with neoadjuvan chemotherapy target-directed treatment

Introduction and Objective: Breast cancer constitutes 11.7% of all cancer types, causing 15.5% of cancer deaths among women in 2020, which is responsable of 685,000 deaths in the world. Breast cancer is a systemic disease and neoadjuvant treatment helps reduce the risk of recurrence by destroying micro metastases in non-metastatic breast cancer, reduces the tumor stage, offers surgery to patients whom surgery cannot be performed as initial therapy, reduce the risk of complications after surgery and to increase the quality of life. In addition, neoadjuvant therapy provides very important information about the prognosis of the patient by showing the in vivo chemotherapy response of the tumor. In the light of this information, our study aimed to investigate the effect of the pathological and clinical response on disease free and overall survival obtained after breast cancer patients who were treated with neoadjuvant chemotherapy . Materials and Methods: Patients with breast cancer , who were treated with neoadjuvant chemotherapy and were 18 years old and older, whom which file data is complete, and pathological diagnosis was confirmed by tissue biopsy and followed up at Dokuz Eylül University Medical Oncology Department between 01.01.2010 and 01.03.2021, were retrospectively searched and included. A total of 118 patients were evaluated retrospectively, demographic, radiological, clinicopathological data and biochemical parameters of the patients were recorded. The analysis of the data were evaluated using the appropriate statistical tests in the SPSS statistical program and the p value of < 0.05 was considered statistically significant. Results: The mean age of the patients was 50.2±12.0 years. Invasive ductal carcinoma was found to be the most common histological type with a rate of 72.6%. The rate of patients with complete pathological response after neoadjuvant therapy was 24.6%. Clinical response was evaluated after neoadjuvant treatment 29.7% of the patients had radiological complete response, 60.2% of the patients had radiological partial response and 10.2% of the patients had stable disease. Comparing the patients with pathological complete response and patients with residual tumor cells, the median overall survival was 130.5 months in the complete response group and 105.4 months in the residual tumor cell group and was found to be statistically significant (p=0.043). Disease-free survival was significantly longer in the patients who had pathological complete response comparing to the patients who had residual tumor cells (119.5 month vs 85.7 month)(p=0,030). When comparing clinical responses, the median overall survival of patients with radiological complete was 115.4 months, partial response group was 109.6 months, and stable disease group was 72.2 months, but this differance was not statistically significant (p=0.794). Comparing disease-free survival times, the patient group with radiological complete response was 102.1 months, the partial response group was 91.8 months, and stable disease was 49.6 months, but this was not statistically significant (p=0.067). Presence of metastatic lymph nodes were found to be significant in predicting mortality in our study (sensitivity=76.5%, specificity=51.0%) (p=0.039). Conclusion: It was determined that complete pathological response in breast cancer patients who was treated with neoadjuvant treatment, had superior disease free and overall survival. Keywords: Breast cancer, Overall Survival, Relapse, Disease Free Survival, Pathological response, Clinical Response