Clinical significance of platelet-derived growth factor receptor-β gene expression in stage II/III gastric cancer with S-1 adjuvant chemotherapy.

Overall survival remains unsatisfactory in stage II/III gastric cancer, even after curative surgery and adjuvant chemotherapy. Platelet-derived growth factor receptor-β (-β) is associated with the proliferation of cancer cells. The present study therefore investigated the association of -β gene expression with patient outcome in 134 stage II/III gastric cancer patients who received adjuvant chemotherapy with S-1. Relative -β gene expression was measured in surgical cancer tissue and adjacent normal mucosa specimens by reverse transcription-quantitative polymerase chain reaction. The -β gene expression levels were found to be significantly higher in the cancer tissues compared with the adjacent normal mucosa. A high level of -β gene expression was associated with a significantly poorer 5-year overall survival rate compared with a low level of -β expression. Upon multivariate analysis, -β gene expression was found to be an independent predictor of survival. Overall, the study indicates that -β overexpression in gastric cancer tissues is a useful independent predictor of outcome in patients with stage II/III gastric cancer who receive adjuvant chemotherapy with S-1.