e22108 Background: GPR87 is a member of G-protein-coupled receptors (GPCRs). Recently, GPR87 was suggested to contribute to the viability of human tumor cells, and the overexpression of GPR87 mRNA was found in many malignant tumors including lung cancer. However, the clinical significance of GPR87 expression in non-small cell lung cancer (NSCLC) has not been well studied. Methods: 127 NSCLC patients who underwent surgery from 1999 to 2004 were investigated. There were 59 adenocarcinomas, 55 squamous cell carcinomas and 13 others. The intratumoral expression of GPR87 was evaluated by immunohistochemistry. The Ki-67 proliferation index was also evaluated. Results: A tumor-specific expression of GPR87 was found in NSCLC in comparison with the surrounding normal tissue. Fifty-nine tumors (46.5%) were found to be high-GPR87 tumors. The high-GPR87 tumors were more frequently found in squamous cell carcinoma than in adenocarcinoma (60.0% versus 37.3%, p=0.02). Regarding the tumor proliferation, the Ki-67 index was significantly higher in high-GPR87 tumors than in low-GPR87 tumors (p=0.04). There was a tendency that the overall survival was worse in patients with high-GPR87 tumors than in low-GPR87 tumors (p=0.22). For the patients with adenocarcinoma, the overall survival was significantly worse in patients with high-GPR87 tumors than in low-GPR87 tumors (p=0.04). Conclusions: GPR87 expression may become a poor prognostic predictor for patient with NSCLC, especially for those with adenocarcinoma. GPR87 may contribute to the cell viability by promoting cell proliferation, has a potential to become a novel therapeutic target for cancer treatment.
Correlation between the Ki-67 proliferation index and response to radiation therapy in small cell lung cancer
