Platelet-activating factor (PAF) receptor expression is associated with histopathological stage and grade and patients' survival in gastric adenocarcinoma.

Platelet activating factor (PAF) has been considered as potent inflammatory lipid mediator that exerts its actions by binding to PAF receptor (PAFR). PAF/PAFR system has been implicated in several pathophysiological states, including tumor progression, angiogenesis and metastasis. The present study aimed to evaluate the clinical significance of PAFR expression in gastric adenocarcinoma. PAFR protein expression was assessed immunohistochemically on 54 gastric adenocarcinoma tissue samples and was analyzed in relation with clinicopathological parameters, tumor proliferative capacity and patients' survival. PAFR was abundantly expressed in all gastric adenocarcinoma cases examined. Increased PAFR expression was significantly more frequently observed in well/moderately compared to poorly differentiated gastric adenocarcinoma cases (p=0.011). PAFR expression was significantly increased in intestinal- compared to diffuse-type cases (p=0.020). Elevated PAFR expression was significantly associated with smaller tumor size, absence of lymph node and organ metastasis and low tumor histopathological stage (p=0.025, p<0.001, p=0.009 and p<0.001, respectively). Additionally, patients presenting elevated PAFR expression had significantly longer survival times compared to those with low PAFR expression (log-rank test, p<0.001). These results support an important potential role of PAFR signalling in gastric malignant disease progression and render further research in this field a necessity.