Expression of leptin protein in gastric cancer and its clinical significance

Abstract

Objective To investigate the relationship between the expression of leptin protein and clinicopathological features and prognosis of gastric cancer. Methods The cancer tissue specimens of 112 patients diagnosed with gastric cancer in Shaanxi Provincial Cancer Hospital from January 2009 to December 2012 were collected. Random number table method was used to select 50 cases of paracancerous normal mucosa tissues as the controls. The expression of leptin protein was detected by using immunohistochemistry. And the relationship between the expression of lepin protein and the clinicopathological features and prognosis was analyzed. Results The positive rate of leptin protein in gastric cancer tissues was higher than that in paracancerous normal gastric mucosa tissues, and the difference was statistically significant [68.8% (77/112) vs. 34.0% (17/50), χ2 = 17.139, P < 0.01]. The expression of leptin protein was associated with tumor vessel invasion, invasion depth and TNM stage (all P < 0.05). The expression of leptin protein was positively correlated with tumor invasion depth and TNM stage (r = 0.265, P = 0.005; r = 0.318, P = 0.001). The 5-year total survival rates of patients with positive and negative expression of leptin protein were 65.2% and 78.4%, respectively, and the difference was statistically significant (χ 2 = 9.526, P = 0.002). The 5-year total survival rates of patients who received neoadjuvant chemotherapy or not were 71.7% and 67.6%, respectively, and the difference was not statistically significant (χ 2 = 2.321, P = 0.128). In patients with positive expression of leptin protein, 5-year total survival rates of patients who received neoadjuvant chemotherapy or not were 47.4% and 74.2%, respectively (χ 2 = 6.336, P = 0.012). In patients with negative expression of leptin protein, 5-year total survival rates of patients who received neoadjuvant chemotherapy or not were 92.3% and 18.2%, respectively (χ 2 = 14.237, P < 0.01). Cox multivariate regression analysis showed that leptin protein expression, lymph node metastasis, pathological grading, vessel invasion and TNM stage were independent prognostic factors for patients with gastric cancer (all P < 0.05). Conclusion Leptin protein is highly expressed in gastric cancer tissues, and it can be used as a marker for judging the prognosis and chemotherapy effect of gastric cancer patients. Key words: Gastric neoplasms; Leptin; Prognosis; Treatment outcome