Clinical implication of CD166 expression in gastric cancer

Background CD166 is one of the cell-surface immunoglobulins, and is well known to regulate leukocyte mobility. Its expression is associated with aggressive tumor behavior. CD166 expression is a prognostic marker in several cancers, but the predictive value of CD166 expression in gastric cancer has not been clarified yet. Patients and Methods A total of 142 gastric cancer patients who consecutively received curative gastrectomy in Kagoshima University Hospital were enrolled in the current study. The patients were composed of 99 men and 43 women, ranging in age from 42 to 84 years (mean 63 years). Cancerous CD166 expression was evaluated immunohistochemically. Results Cancerous CD166 expression was identified in not only cellular membrane but also cytoplasm. The rates of membranous and cytoplasmic CD166 positivities were 25.4% and 34.4%, respectively. Cytoplasmic and membranous CD166 positivities were significantly correlated with nodal involvement and vascular invasion. Survival analysis of the 142 gastric cancer patients revealed that membranous CD166-positive group (median survival 18.6 months, range 0.3-104.5 months) had a significantly poorer outcome than CD166-negative group (median 25.7 months range 1.4-106 months) (P < 0.05). Conclusions Membranous CD166-positivity may contribute to one of the promising prognostic markers in gastric cancer.