Co-expression of CD44/MyD88 is a poor prognostic factor in advanced epithelial ovarian cancer.

Background: Cluster of differentiation 44 (CD44)/myeloid differentiation factor 88 (MyD88) is the molecular characterization of EOC stem cells. An important characteristic of CD44+/MyD88+ epithelial ovarian cancer (EOC) cells, which differentiate them from the CD44-/MyD88- EOC cells, is the presence of a functional TLR4-MyD88-NFkB pathway. The aim of our study is to investigate the clinical significance of CD44/MyD88 co-expression in EOC.

Methods: A total of 138 specimens of ovarian tissues was detected CD44 and MyD88 expression by immunocytochemistry, including EOC (N=108), borderline tumors (N=10), benign cysts (N=10) and normal ovarian tissue (N=10). The association of CD44/MyD88 co-expression with clinicopathological factors and outcomes was analyzed.

Results: The expression of CD44 was showed distinct difference in EOC (53 of 108, 49.1%), in borderline tumors (3 of 10, 30.0%), in benign cysts (2 of 10, 20.0%) and normal ovarian (2 of 10, 20.0%). A total of 41 (38.0%) cancers showed a combined expression of CD44/MyD88. The expression of CD44 and MyD88 had definitely correlativity (r=0.21, P=0.026). CD44/MyD88 co-expression was associated with tumor progression, metastasis, and recurrence in advanced EOC, and an independent prognostic factor for disease-free survival and overall survival.

Conclusions: CD44/MyD88 co-expression has been shown to contribute to EOC progression and outcome directly and has a promising as a therapeutic target in EOC.