Response Rate to Neoadjuvant Chemotherapy in Patients with Locally Advanced Breast Cancer Based on Common Molecular Receptors

Abstract

Background and Objective: Breast cancer has a high prevalence and mortality rate in the world and also in Iran. Neoadjuvant chemotherapy (NAC) is one of the treatment methods to improve patient survival. This study aimed to determine the response rate to NAC in patients with locally advanced breast cancer based on common molecular receptors. Methods: This descriptive-analytical study was conducted on 100 patients with breast cancer (mean age= 41.14±10.06 years) referring to the surgical clinic of the Fifth Azar Educational and Therapeutic Center in Gorgan, Iran during 2013-18. Patients without distant metastasis underwent NAC treatment regimen followed by surgery. Demographic characteristics, types of drugs, and molecular receptor characteristics, and their response to treatment were recorded in a checklist. Treatment response and overall patient survival were evaluated. Results: The mean tumor size before NAC was 3.01±2.47 cm (range= 0-8, median= 2) and 16% were determined to be grade one, 52% were determined to be grade 2, and 32% were determined to be grade 3. Thirty-six percent of patients had a positive family history. Forty-six percent were estrogen receptor (ER) positive, 40% were PR positive, 22% were human epidermal growth factor receptor 2 (Her-2) positive, and 78% were Her-2 negative. Thirty-six percent had a Ki-67 index greater than 30%. Eighteen percent of patients had a complete pathological response, and 82% had a partial or negative response. In terms of family history of breast cancer, Her2, ER, progestrone receptor (PR), Ki-67 receptor status, histological grade, tumor size, and axillary lymph nodes, there was a significant statistical difference between the two groups with and without complete pathological response (P<0.05). Conclusion: The rate of complete pathological response to NAC in patients with locally advanced breast cancer was 18%.

Keywords

• breast neoplasms
• chemotherapy adjuvant
• pathologic complete response
• survival
• mortality