Decreased expression of CADM1 and CADM4 are associated with advanced stage breast cancer

Cell adhesion molecule (CADM) genes encode immunoglobulin superfamily molecules, which are involved in cell-cell adhesion in a number of human epithelia. Through the maintenance of epithelia, CADM genes protect against malignant conversion and metastasis. Whilst numerous in vitro studies have investigated the molecular characteristics of CADM1 and CADM4 and in vivo studies have investigated CADM1 and CADM4 expression in a number of tumor types, the roles of CADM1 and CADM4 have yet to be elucidated. Therefore, in the present study, CADM1 and CADM4 expression levels were evaluated using immunohistochemistry staining in 208 patients with breast cancer and compared with clinicopathological factors. CADM1 and CADM4 expression levels were negative in 160 (76.9%) and 166 (79.8%) of the 208 cases, respectively. The lack of expression in these cases was associated with advanced tumor stage, suggesting that inactivation of CADM1 and CADM4 promotes breast cancer development. The prognostic role of CADM1 and CADM4 in breast cancer was also evaluated and the expression of CADM1 and CADM4 were not associated with cancer-specific survival or overall survival rate in the cohort of patients in the present study. Whilst these results suggested that CADM1 and CADM4 possess tumor suppressive roles, further functional experiments are required to address the important mechanisms involving CADM1 and CADM4.