Objective: Breast cancer is a major cause of death in women worldwide including Thailand. The subject of molecular levels related with carcinogenesis and metastasis of breast cancer is poorly understood. The present study aimed to determine the expression of β-klotho (KLB) protein in breast cancer and its relation to axillaries lymph node metastasis.

Materials and Methods: KLB expression in 53 paraffin-embedded sections (34 breast cancer and 19 normal tissues) was determined by the immunohistochemistry method using monoclonal antibody specific to KLB protein. The clinico-pathological data of patients were also collected and analyzed with the laboratory data.

Results: The result showed a significant higher KLB expression in breast cancer compared to normal breast tissue (p=0.038). KLB expression was more frequently found in breast cancer tissue with metastasis to axillaries lymph node (43.75%, 16 of 34 cases) compared to breast cancer tissue without metastasis to axillaries lymph node (5.56%, 18 of 34 cases) and normal breast tissue (0%, 19 cases). Higher KLB expression was found in breast cancer with axillaries lymph node metastasis when compared to those without axillaries lymph node metastasis using a cut off value of immunohistochemistry index of 1 or more (p=0.015). In addition, the high levels of KLB expression (IHC index of 1 or more) can be a marker for axillaries lymph node metastasis (p=0.024, Exp (B)=0.032).

Conclusion: The present research was the first study in Thailand showing KLB protein overexpression in breast cancer, especially in breast cancer cases with axillaries lymph node metastasis. The result suggests the role of KLB protein in the process of cancer invasion and metastasis. Moreover, KLB protein overexpression could be a potential biomarker for breast cancer metastasis.

Keywords: β-Klotho, KLB, Axillaries lymph node, Metastasis, Breast cancer

Received 18 Mar 2019 | Revised 6 Jun 2019 | Accepted 7 Jun 2019