Preventing Venous Thromboembolism in Ambulatory Patients with Cancer: A Narrative Review

Treatment and prevention of cancer-associated thrombosis in the Netherlands: A national survey

Background

In the recent years, numerous studies on the optimal treatment and prevention of cancer-associated venous thromboembolism (VTE) have been published, leading to updated (inter)national guidelines. These include direct oral anticoagulants (DOACs) as the first-line treatment agent in general and the recommendation of primary thromboprophylaxis in selected ambulatory patients.

Objectives

The objective of this study was to evaluate the clinical practice regarding treatment and prevention of VTE in patients with cancer in the Netherlands and practice variation among different specialties.

Methods

An online survey was conducted between December 2021, and June 2022, among Dutch physicians (oncologists, hematologists, vascular medicine specialists, acute internal medicine specialists, and pulmonologists) treating patients with cancer, in which we explored the treatment of choice for cancer-associated VTE, the use of VTE risk stratification tools, and primary thromboprophylaxis.

Results

A total of 222 physicians participated, of whom the majority (81%) used DOACs as a first-line agent for treating cancer-associated VTE. The treatment varied between the following specialties: hematologists and acute internal medicine specialists more often prescribed low-molecular-weight heparin than physicians of the other specialties (OR, 0.32; 95% CI, 0.13-0.80). The minimum duration of anticoagulant treatment was usually 3 to 6 months (87%), and treatment was extended when the malignancy was still active (98%). Regarding the prevention of cancer-associated VTE, no risk stratification tool was used. Three quarters of respondents never prescribed thromboprophylaxis to ambulatory patients, mostly because the thrombosis risk was not perceived high enough to justify prophylaxis.

Conclusion

Dutch physicians largely adhere to the updated guidelines regarding the treatment of cancer-associated VTE but less to the recommendations for its prevention.

Cancer-Associated Thrombosis: A Clinical Scoping Review of the Risk Assessment Models Across Solid Tumours and Haematological Malignancies

Cancer-associated thrombosis (CAT) is a leading cause of death in cancer patients receiving outpatient chemotherapy. The latest guidelines emphasize stratifying the patients in terms of CAT risks periodically. Multiple risk assessment models (RAMs) were developed to classify patients and guide thromboprophylaxis to high-risk patients. This study aimed to discuss and highlight different RAMs across various malignancy types with their related advantages and disadvantages. A scoping review was conducted using predefined search terms in three scientific databases, including Google Scholar, Science Direct, and PubMed. The search for studies was restricted to original research articles that reported risk assessment models published in the last thirteen years (between 2008 and 2021) to cover the most recently published evidence following the development of the principal risk assessment score in 2008. Data charting of the relevant trials, scores, advantages, and disadvantages were done iteratively considering the malignancy type. Of the initially identified 1115 studies, 39 studies with over 67,680 patients were included in the review. In solid organ malignancy, nine risk assessment scores were generated. The first and most known Khorana risk score still offers the best available risk assessment model when used for high-risk populations with a threshold of 2 and above. However, KRS has a limitation of failure to stratify low-risk patients. The COMPASS-CAT score showed the best performance in the lung carcinoma patients who have a higher prevalence of thrombosis than other malignancy subtypes. In testicular germ cell tumours, Bezan et al RAM is a validated good discriminatory RAM for this malignancy subtype. CAT in haematological malignancy seems to be under-investigated and has multiple disease-related, and treatment-related confounding factors. AL-Ani et al score performed efficiently in acute leukemia. In multiple myeloma, both SAVED and IMPEDED VTE scores showed good performance. Despite the availability of different disease-specific scores in lymphoma-related thrombosis, the standard of care needs to be redefined.