Loss of Leucine Zipper Putative Tumor Suppressor 1 (LZTS1) Expression Contributes to Lymph Node Metastasis of Breast Invasive Micropapillary Carcinoma

Breast invasive micropapillary carcinoma (IMPC) is a rare subtype of breast cancer with a high potential of lymph node metastasis, aggressive clinical behavior, and poor disease-free or overall survival. Expression of leucine zipper putative tumor suppressor 1 (LZTS1) was frequently lost or reduced in breast cancer tissues. This study investigated the expression of LZTS1 protein in breast IMPC tissues using immunohistochemistry. In addition, somatic LZTS1 mutations and promoter methylation were assessed to determine an association with clinicopathological data from IMPC patients. LZTS1 protein was downregulated in 62 (62 %) of 100 IMPC tissue samples and was significantly associated with lymph node metastasis ( P