Association of Preoperative Serum Levels of CEA and CA15-3 with Molecular Subtypes of Breast Cancer

Abstract

Objectives. Molecular subtypes are employed as a guide for targeted treatment and important prognostic factors. This study focused on investigating the association of serum levels of CEA, CA15-3, and CA125 with clinicopathological characteristics of breast cancer to find prognostic markers for breast cancer and provide precise targeted therapy. Materials and Methods. In this study, 961 breast cancer patients with preoperative serum levels of CEA, CA15-3, and CA125 and molecular subtypes were analyzed. Cut-off values of 5 ng/ml, 25 U/ml, and 35 U/ml were used for CEA, CA15-3, and CA125, respectively. The $\chi$ 2 test and Fisher exact test along with logistic multivariate regression analysis were performed for investigating the correlation of CEA, CA15-3, and CA125 serum levels with molecular subtypes and associated factors. Results. An increase in the serum concentrations of CEA, CA15-3, and CA125 was discovered in 48 (4.99%), 54 (5.62%), and 55 (5.72%) breast cancer patients, respectively. Univariate analysis demonstrated that the levels of CEA ( $p<0.01$ ) and CA15-3 ( $p<0.05$ ) were significantly linked with molecular types of breast cancer. Moreover, patients having larger tumor size ( $p<0.01$ , $p<0.0001$ , and $p<0.05$ , respectively) along with nodal metastasis ( $p<0.05$ , $p=0.0001$ , and $p<0.05$ , respectively) exhibited higher rates of elevated CEA, CA15-3, and CA125 levels. Status of Her-2 positive ( $p<0.01$ ) had a significant connection with elevated CEA levels. Multivariate analysis further indicated that molecular subtypes were independent factors associated with CEA and CA15-3 levels. Also, Her-2 status was significantly and independently related to CEA levels. Conclusion. Preoperative serum levels of CEA and CA15-3 were independently associated with molecular subtypes of breast cancer. CEA and CA15-3 might improve the prognostic prediction for patients with breast cancer and inform the selection of specific therapies. A further biological analysis is needed for investigating the relationship between Her-2 expression and CEA levels.