Loss of KAI1 expression in gastric cancer

Background/Aims: The purpose of this study was to determine whether the loss of KAI1 expression was related to the clinicopathologic features of patients with gastric cancer. Methodology. The expression of KAI1 protein was investigated retrospectively in 174 patients with gastric cancer. Immunohistochemical staining of the paraffin sections was performed using polyclonal antibody to KAI1. Results: KAI1 was consistently and highly expressed in normal gastric epithelium, while 47 (27%) of 174 patient samples had KAI1-positive expression in the primary gastric carcinoma. There were no significant differences of age, gender, and tumor location. With regard to the clinicopathological. characteristics, significant differences were observed in histological types (p<0.001), increased tumor stage (p<0.001), lymph node (p<0.001) and distant metastasis (p<0.001). KAI1-negative patients had a worse prognosis than that of positive patients in overall survival, but loss of KAI1 expression was not an independent prognostic indicator (p=0.779) by multivariable analysis. Conclusions: Loss of KAI1 of expression is likely to predict metastasis and poor clinical outcome in gastric cancer patients. For the purpose of predicting the prognosis of gastric cancer patients, it is important to discriminate whether the carcinoma cells have loss of KAI1 expression.