Plasma adiponectin and gastric cancer.

BACKGROUND Recently, increased body weight has been associated with an increased risk of cancers at multiple specific sites, including gastric cancer. Adiponectin is a peptide hormone secreted by adipose tissue, affecting the proliferation and insulin sensitivity of various types of cells. Moreover, the circulating level of adiponectin has been reported to be inversely related to body mass index. METHODS Fasting plasma levels of adiponectin were determined in 75 patients with gastric cancer and 52 healthy controls using an ELISA. In these patients, we analyzed the association between plasma adiponectin level and gastric cancer risk as well as various clinicopathologic characteristics. RESULTS Plasma adiponectin level was significantly lower in patients with gastric cancer than in healthy controls (9.1 +/- 6.2 versus 13.3 +/- 9.4 ng/mL, P < 0.01) and showed a significant modest inverse relation with the gastric cancer (odds ratio, 0.92; 95% confidence interval, 0.85-0.97; adjusted odds ratio, 0.89; 95% confidence interval, 0.84-0.95], although body mass index was not different. In addition, adiponectin level was extremely low in patients with upper gastric cancers (upper, 5.5 +/- 4.1 ng/mL; middle, 9.7 +/- 6.4 ng/mL; lower, 10.7 +/- 4.1 ng/mL; P = 0.012). Furthermore, adiponectin level tended to decrease as the tumor stage increased (stage I, 9.9 +/- 6.9 ng/mL; stage II, 8.7 +/- 5.5 ng/mL; stage III, 8.6 +/- 4.1 ng/mL; stage IV, 5.2 +/- 6.2 ng/mL; P = 0.34). Interestingly, in 32 patients with undifferentiated cancer, serum adiponectin showed a negative correlation with pathologic findings such as tumor size, depth of invasion, as well as tumor stage (P < 0.05), but no correlation in the remaining 43 patients with differentiated cancer. CONCLUSIONS Our results suggest that a low plasma adiponectin level is associated with an increased risk for gastric cancer and raise the possibility that adiponectin has a potential role in the progression of gastric cancer, especially in undifferentiated type cancers in the upper stomach.