Thromboembolic events (TE) among patients with metastatic pancreatic ductal adenocarcinoma (mPDA) after chemotherapy (Chemo).

Abstract

280 Background: Clinical trials suggest that patients with mPDA are at high risk of TE from both disease and treatment. TE rates and anticoagulant use among mPDA patients after first line chemo were investigated. Methods: Medicare beneficiaries enrolled in parts A, B, and D; diagnosed with mPDA; aged ≥ 65 years; and starting chemo between 1/1/2007 and 12/31/2012 were obtained from Surveillance, Epidemiology, and End Results (SEER)-Medicare data. Eligible patients were enrolled from 12 months before chemo and followed until death, post-chemo disenrollment, or 12/31/2012. Arterial (ICD-9 410-411, 433-434), venous (ICD-9 415.1x, 453.4x, 453.8x, 453.9), and total TE were defined as ≥ 2 outpatient diagnoses ≥ 30 days apart, one inpatient diagnosis, or one outpatient diagnosis followed by outpatient anticoagulants within 90 days. Post-chemo TE incidence was calculated as the number of first events per 100 person-years (PY) for patients with and without TE 12 months before chemo. Time from chemo to first TE was estimated using the Kaplan-Meier (KM) method. Results: Among 1,308 eligible patients, mean age was 74 years [range 65-93]; 56% were female; 85% had no prior TE. Overall, 419 (32%) had a TE after chemo including 121 (9%) arterial and 363 (28%) venous TE. The table shows incidence, and time to TE for those with and without prior TE. Outpatient anticoagulants were prescribed for 276 (25%) patients with no prior TE and 110 (57%) patients with prior TE. Table. TE incidence and time to TE among mPDA patients after chemo Conclusions: mPDA patients face a substantial risk of TE after chemo, with nearly one-third of patients without prior TE and one-half of patients with prior TE experiencing events during treatment. These high rates of TE indicate the importance of conducting risk assessments for preventive measures early during a patients’ care.[Table: see text]