GHRL and gastric cancer: Circulating ghrelin levels were lower in gastric cancer patients (SMD=-0.255, 95%CI: -0.528 to 0.017, P < 0.00001), but with high heterogeneity (I<sup>2 </sup>= 88.8%).<h4>Conclusion</h4>The circulating ghrelin levels in patients with gastric cancer were lower than in controls.