Thrombocytosis as a Predictor of Distant Recurrence in Patients with Rectal Cancer∗

Background and AimsThrombocytosis is frequently observed in patients with malignancy. We undertook this study to determine the prognostic value of thrombocytosis in patients with rectal cancer.MethodsWe performed a retrospective study of patients undergoing low anterior resection for rectal cancer between January 2000 and March 2007. Preoperative platelet count was measured before surgery. Postoperative platelets were determined 1 month after surgery. Two-tailed p values <0.05 were considered statistically significant.ResultsOne hundred sixty three patients with rectal cancer were included in the study. Preoperative platelet count >350,000 was found in 8% of patients. Postoperative platelet count >350,000 was found in 6% of patients. Distant metastases were found in 17 patients (10.4%). Significant variables in the multivariate analyses were preoperative platelets >350,000 (p = 0.001), postoperative platelets >350,000 (p = 0.002), carcinoembryonic antigen >13 ng/dL (p = 0.003). Patients with preoperative platelet count <350,000 showed a 5-year survival rate of 81%, whereas patients with platelet count >350,000 had a 25-month survival [95% confidence interval (CI): 20–26]; p <0.001. Patients with postoperative platelets <350,000 showed a 5-year survival rate of 80%, whereas patients with platelets >350,000 showed a 3-year survival rate of 37.5% (p <0.05).ConclusionsPre- or postoperative platelet count >350,000 is associated with poor survival in patients with rectal cancer. The measurement of platelets is a clinical marker useful to define the prognosis for patients with rectal cancer.