Early detection of venous thromboembolism after the initiation of chemotherapy predicts a poor prognosis in patients with unresectable metastatic pancreatic cancer who underwent first-line chemotherapy with gemcitabine plus nab-paclitaxel

BACKGROUND: Pancreatic cancer is associated with a high thromboembolism risk. We investigated the significance of early venous thromboembolism (VTE) detection in patients with unresectable metastatic pancreatic cancer (UR-MPC) who received first-line chemotherapy with gemcitabine plus nab-paclitaxel (GnP). METHODS: This single-center retrospective study enrolled 174 patients with UR-MPC who underwent GnP as a first-line chemotherapy from April 2017 to March 2020. The early detection of VTE (deep venous thrombosis and pulmonary thromboembolism) was defined as diagnosis by the first follow-up CT scan after the initiation of chemotherapy. We compared the patients with early detection of VTE (VTE (+) group) with the others (VTE (-) group). We examined overall survival (OS), progress free survival (PFS), severe adverse events, and predictors associated with OS using the Cox proportional hazards model. RESULTS: Early detection of VTE was observed in 17 patients (9.8%). Thirteen patients were diagnosed with VTE at treatment initiation, and four patients were diagnosed after treatment initiation. The median time to diagnosis after treatment initiation was 55 days (range: 31–71 days). Only 3 patients were symptomatic. The VTE (+) group exhibited worse OS and PFS than the VTE (-) group (OS: 259 days vs. 400 days, P < 0.001; PFS: 120 days vs. 162 days, P = 0.008). The frequency of grade 3–4 adverse events was not significantly different. Although the performance status was poorer in the VTE (+) group, VTE was identified as a statistically significant independent predictor for OS in multivariate analyses (HR, 1.87; 95% CI, 1.02–3.44; P = 0.041). CONCLUSIONS: Early VTE detection is a predictor of a poor prognosis in UR-MPC patients who receive GnP as first-line chemotherapy, suggesting that screening VTE for patients with UR-MPC is crucial, even if patients are asymptomatic.