Creatine Kinase (CK)-MB and CK-MB-to-Total-CK Ratio: A Novel Predictive Marker for Pathologic Complete Response in Breast Cancer Treated with Neoadjuvant Chemotherapy

Abstract

Breast cancer is the most common cancer and neoadjuvant chemotherapy(NAC) is one of the important treatment modalities in early stage breast cancer. The aim of this study was to investi-gate the ability of serum CK-MB and CK-MB/CK to be an ideal predictive marker for pathologic complete response (pCR) in breast cancer patients receiving NAC and to determine its rela-tionship with clinicopathologic factors. A total of 135 breast cancer patients receiving NAC were included in this retrospective study. The pre-NAC serum laboratory values and clinicopathologi-cal features of the patients were recorded. Regression analysis was used to do predictive factor analysis for pCR. In the statistical analysis, serum CK-MB level was associated with axillary status, PgR status, ER status, and HER2 status. A significant relationship between CK-MB/CK and axillary status and histological grade was found. PgR negativity, ER negativity, high histo-logical grade, axillary negativity, NLR, CK-MB elevation, and high CK-MB/CK ratio were found to be predictive factors for pCR in the univariate regression analysis.CK-MB (OR= 3.48, p= 0.032) and CK-MB/CK ratio (OR= 3.16, p= 0.028) were revealed to be strong predictors of pCR in established multivariate models.In survival analysis, recurrence-free survival (RFS) were shorter in patients with low CK-MB/CK ratio (p= 0.045). There was no significant relationship between CK-MB level and RFS (p= 0.315). In summary, in breast cancer patients who have re-ceived NAC, serum CK-MB level and CK-MB/CK ratio are independent predictors of pCR.To the best of our knowledge, this study is the first to assess these variables’ predictive impact on NAC response in breast cancer patients. Keywords: Breast cancer, Creatine kinase, CK-MB-to-total-CK ratio, Neoadjuvant chemotherapy, Predictive