Abstract: Objective To explore the relationship between thrombocytosis and gastric cancer at the points of clinicopathological stage and prognosis. Methods The clinical data of 156 gastric cancer patients from January 2005 to  January 2007 were retrospectively analyzed, and the status of patients was obtained through telephone calls. The frequency of patients with thrombocytosis in different clinicopathological stages was analyzed, and comparison of survival time  was made between normal PLT groups and thrombocytosis groups. Results 20.5% patients with gastric cancer were accompanied with thrombocytosis in 156 cases,  and the frequency of  patients with thrombocytosis in Ⅰ, Ⅱ, Ⅲ, Ⅳ stage were 4.8%, 21.7%, 24.4%, 30.4%,  and the difference was statistically significante (χ2=8.768, P=0.003). Patients with thrombocytosis had a shorter survival time than those with normal platelet counts (one year survival rate： 59.4% vs 81.5%, χ2=6.984, P=0.008; three years survival rate： 34.4% vs 63.7%, χ2=8.968, P=0.003). Conclusion In gastric cancer, thrombocytosis is associated with TNM stage．The gastric cancer patients with thrombocytosis have poorer prognosis than those without thrombocytosis.

Key words: Thrombocytosis, Gastric neoplasms, Neoplasm staging, Prognosis