Prognostic Significance of the Absolute Monocyte Counts in Lung Cancer Patients with Venous Thromboembolism

We investigated the clinical significance of the absolute monocyte count (AMC) as a predictor of the response to anticoagulation and survival in lung cancer patients with venous thromboembolism (VTE). We retrospectively reviewed 1707 patients with pathologically proven lung cancer who visited the hospital between July 2008 and May 2014. Among them, the clinical data of patients newly diagnosed with VTE and treated with anticoagulation were compared between the low and high AMC groups according to the median value of AMC (640/μL) at the time of VTE diagnosis. The incidence of VTE was 7.9 % during the study period. Most of the patients had non-small-cell lung cancer (82.1 %), stage IV (64.2 %), and pulmonary thromboembolism (76.1 %) and were incidentally diagnosed with VTE (76.9 %). The patients' characteristics and laboratory values were not significantly different between the low and high AMC groups. Among patients available for evaluation of the response to anticoagulation, the high AMC group was significantly more refractory to anticoagulation than the low AMC group (no response to anticoagulation, 21.7 vs. 6.8 %, respectively; p = 0.044). Additionally, the high AMC group showed worse overall survival (OS) than the low AMC group (median, 9.6 vs. 5.9 months; p = 0.038). On multivariate analysis, high AMC, low albumin, and advanced stage were independent poor prognostic factors for OS. High AMC is associated with refractoriness to anticoagulation and poor prognosis in lung cancer patients with VTE.