Correlation between Serum Interleukin-6 Levels and Clinical Response to Anthracycline-Based Neoadjuvant Chemotherapy Regimen in Locally Advanced Breast Cancer Patients

Abstract

Background: Neoadjuvant chemotherapy is the initial therapy and the main pillar of treatment for locally advanced breast cancer (LABC). Currently, there is marker that widely accepted as a predictive factor for chemotherapy response in LABC. Elevated serum interleukin-6 (IL-6) levels and tumor sites have been proposed as prognostic markers for breast cancer. In this study, we aimed to examine the association between serum IL-6 levels with clinical response after the administration of neoadjuvant chemotherapy. Methods: This study is an observational analytic study with a cohort prospective character to determine the relationship between IL-6 serum levels and clinical response to anthracycline-based neoadjuvant chemotherapy in locally advanced breast cancer (LABC) patients at Dr. Soetomo General Hospital during April 2021 to September 2021 with a total sample of 38 patients. Results: Fourteen patients (77.8%) had a positive response in the low IL-6 level group and 4 patients (22.2%) had a negative response. In high IL-6 level group, 4 patients (40%) had a positive response and 16 patients (80%) had a negative response. The cut off of 15.495 pg/mL was used as cut off value for IL-6 to predict the clinical response to chemotherapy. The sensitivity, specificity, PPV, NPV, and accuracy of IL-6 to predict the clinical response after chemotherapy were 80.0%, 77.8%, 80.0%, 77.8%, and 78.9%, respectively. Conclusion: There is a relationship between serum IL-6 levels and clinical response to anthracycline-based neoadjuvant chemotherapy regimens in locally advanced breast cancer (LABC) patients. Keywords: interleukin-6, clinical response, locally advanced breast cancer.