In patients with advanced pancreatic ductal adenocarcinoma (aPDAC), increased dose primary thromboprophylaxis (IDPTP) should be regularly reviewed beyond 3 months, finds a study by a team at Hull University Teaching Hospitals.
The study, published in the Thrombosis Journal, reports on the efficacy (reduction of all type thromboembolic events [ATTE]), safety (incidence of Major Bleeding [MB]), and compliance in a single-centre cohort of aPDAC patients receiving first-line chemotherapy and IDPTP with low molecular heparin (LMWH).
From May 2009 to October 2016, 82 patients received IDPTP-LMWH with dalteparin.
The schedule was:
- ≤55 kg: 7500 IU.
- 55-80 kg: 10,000 IU.
- >80 kg: 12,500 IU.
MB was reported using the International Society of Thrombosis and Haemostasis (ISTH) criteria. ATTE was defined as any arterial or venous event, incidental or clinically symptomatic, including visceral VTE.
Mean and median time on dalteparin was 10.2 (95%CI 8.1-12.4) and 8.0 (95%CI 6.2-9.7) months, respectively. ATTE was observed in seven (8.5%) patients, with a median time on IDPTP of 6.2 months (95% CI 10.0-13.2). MB was seen in 10 (12.2%) patients, with a median time on IDPTP of 4.5 months (95% CI 1.6-7.4).
Six major bleeds (60%) were identified as a direct or indirect result of aPDAC. Thromboembolism and bleeding were late events. No impact of thromboembolism or bleeding on overall survival was observed.
Eighty-one patients had died at the time of data collection, with a median overall survival time of 8.7 months (95%CI 6.4-11.0).
The data suggest IDPTP-dalteparin is associated with lower ATTE occurrence rates than expected and comparable major bleeding rates. Since ATTE and MB were late events, the authors recommend that IDPTP should be regularly reviewed beyond 3 months in this patient population.