Correlation between expression of leptin and clinicopathological features and prognosis in patients with gastric cancer

Background: The relationship between the expression of leptin in the tissue of gastric cancer and the clinicopathological features as well as patients' outcome were investigated. Methods: Sixty-one gastric cancer specimens were investigated by immunohistochemical studies with anti-leptin and anti-vascular endothelial growth factor (VEGF) antibodies and by monitoring patients for at least 3 years after surgery. Results: A positive rate of leptin expression was significantly associated with Borrmann classification (Borrmann type 1 and type 2 68.2% vs Borrmann type 3 and type 4 or unclassified 35.3%), tumor histology (well differentiated tumors 87.5% vs poorly differentiated tumors 48.9%), lymph node metastasis (with 69.0% vs without 36.8%) and stage (stage III + IV 69.0% vs stage I + II 36.8%). There was a significant association between leptin expression and VEGF expression. In the poorly differentiated group, the overall survival rate for patients with a weak expression of leptin (histochemistry score < 0.5) was significantly higher than that in patients with a strong expression (histochemistry score =0.5). The Cox proportional hazards model identified serosal involvement, tumor size, metastasis, tumor histology, leptin expression, lymph node metastasis, age and postoperative chemotherapy as significant prognostic factors. Conclusions: The expression of leptin in the tissue of gastric cancer was significantly associated with tumor histology, Borrmann classification, lymph node metastasis and stage of gastric cancer. In patients with poorly differentiated gastric cancer, a poor prognosis was found in those with a strong expression of leptin.