Poor prognosis associated with thrombocytosis in patients with gastric cancer

Background: Thrombocytosis is commonly associated with malignant disease and has recently been suggested to be a poor prognostic indicator in patients with lung cancer and gynecological cancers. The prevalence of thrombocytosis in patients with gastric cancer was reviewed, and its association with poor prognosis was investigated. Methods: Platelet count (PLT) and hemoglobin concentrations (Hb) were reviewed in 369 consecutive patients with histologically verified gastric cancer from 1994 to 2000. Differences between categories were analyzed with analysis of variance, and survival was compared by using the log-rank test on the Kaplan-Meier life table. Multivariate Cox regression analysis was used to evaluate whether thrombocytosis is an independent prognostic marker. Results: Thrombocytosis was found in 42 patients, and anemia was found in 200 patients. PLT was negatively correlated with Hb. Mean PLT was significantly increased in patients with noncurative operations. There was a positive correlation between the depth of tumor invasion and PLT. One- and 3-year survival expectancies in patients with or without thrombocytosis were 52.4% and 23.4% and 85.7% and 72.9%, respectively. PLT was identified as an independent prognostic factor after lymph node metastasis and depth of tumor invasion. Conclusions: Thrombocytosis is an independent prognostic indicator of survival in patients with gastric cancer.