Preoperative platelet count predicts survival after resection of periampullary adenocarcinoma.

BACKGROUND/AIMS: Thrombocytosis or thrombocytopenia have been shown to act as negative predictors of outcome for various solid tumors. No such effect is known for periampullary cancer. The preoperative peripheral blood platelet count impacts on outcome after resection of pancreatic and other periampullary adenocarcinomas.
METHODOLOGY: Clinicopathologic information, treatment aspects, and outcome parameters of patients undergoing pancreatectomy at City of Hope Cancer Center were retrospectively collected and tabulated. The impact of the preoperative platelet count on postoperative recovery, disease-free survival, and overall survival was analyzed.
RESULTS: Between 1988 and 1998, 65 patients underwent partial or total pancreatectomy at City of Hope Cancer Center, 49 of whom had a diagnosis of pancreatic or periampullary adenocarcinoma. There were 26 females and 23 males, with a median age of 64 years (range: 24-86). Median preoperative platelet count was 308 (x10(9)/L; range: 104 to 547). Diagnoses were pancreatic (n = 28), duodenal (n = 12), and bile duct/ampullary cancer (n = 9). Procedures included pancreatoduodenectomy (n = 42), distal pancreatectomy (n = 4), and total pancreatectomy (n = 3). Six patients underwent a splenectomy. A lower preoperative platelet count was correlated to a shortened prothrombin time (P = 0.02), and a positive resection margin (P = 0.01), but not operative blood loss or transfusion requirements. Postoperative complications and hospital stay were not affected by the platelet count. Preoperative platelets of < 300 were associated with a decreased median overall survival (13 vs. 33 months, P = 0.02) and disease-free survival (11 vs. 29 months, P = 0.02), at a median follow-up of 14 months (18 for survivors). On multivariate analysis, the platelet count remained a significant predictor of survival in addition to grade, perineural invasion, the primary tumor size, and the surgeon.
CONCLUSIONS: Based on these retrospective data, a lower preoperative platelet count correlates with inferior, a higher count with superior survival outcome after resection of periampullary cancer. The mechanism is unclear, but may relate to general factors (bone-marrow suppression or hypersplenism for low platelets, systemic antitumor mediators for high platelets) or platelet-specific effects (platelet influence on tumor angiogenesis or metastatic efficiency). The preoperative thrombocyte count should be considered a parameter with potential clinical significance in prospective clinical studies of periampullary neoplasms.