[Impact of platelet count on prognosis of stage II-III colorectal cancer receiving adjuvant chemotherapy].

Objective: To analyze the impact of platelet count on the prognosis of stage II-III colorectal cancer receiving adjuvant chemotherapy.
Methods: Clinical and follow-up data of 286 patients with stage II-III colorectal cancer receiving adjuvant FOLFOX chemotherapy from March 2003 to October 2011 were analyzed retrospectively. Associations of baseline blood platelet count before chemotherapy and nadir blood platelet count during chemotherapy with relapse and death after adjuvant chemotherapy were analyzed by ROC curve and the optimal cutoff was selected. The association of the blood platelet count and the prognosis was analyzed by Kaplan-Meier and Cox regression model.
Results: ROC curve showed the baseline blood platelet count was associated with recurrence (AUC=0.588, P=0.034). The optimal cutoff affecting recurrence was 276×10(9)/L. Kaplan-Meier showed those with baseline platelet count >276×10(9)/L receiving adjuvant chemotherapy had worse disease free survival (DFS) than those with baseline platelet count ≤276×10(9)/L, whose 5-year disease free survival(DFS) was 66% and 80% respectively (P=0.013). Cox regression analysis revealed baseline platelet count >276×10(9)/L was an independent unfavorable factor for DFS of adjuvant chemotherapy in colorectal cancer (HR=1.865, 95% CI: 1.108-3.141, P=0.019).
Conclusion: Colorectal cancer patients receiving adjuvant chemotherapy with baseline platelet count >276×10(9)/L have worse prognosis.