Navigating venous thromboembolism risks in lung cancer patients

To the Editor,

Dr Liang and colleagues' review provided valuable insights into the venous thromboembolism (VTE) risk prediction models for patients with lung cancer. ¹

VTE manifests as deep venous thrombosis or pulmonary embolism, presenting as a severe clinical condition. However, VTE is a dynamic condition with constantly changing features across clinical, radiological, functional, and laboratory findings, not a static disease. Moumneh et al. evaluated 14 660 medical inpatients and found the commonly used tools, including Caprini, IMPROVE, and Padua VTE risk scores, have poor discriminative ability to identify those not critically ill at risk of VTE. ² However, there has yet to be a consensus regarding the preferred VTE risk assessment tool.

There is a limitation of the study by Liang et al. in not distinguishing between symptomatic and asymptomatic VTE cases, ¹ a crucial differentiation given the clinical significance and impact on patient outcomes of symptomatic cases. Underestimation of VTE is prevalent due to the lack of systematic screening, which has been mentioned in many studies. While VTE is linked to increased mortality, many clinicians suggested extended thromboprophylaxis, irrespective of symptoms. However, it is essential to consider patient preferences and potential impacts on their quality of life. For idiopathic VTE, wildly unrelated to surgery or trauma, lifelong prevention strategies may be necessary. However, postoperative VTE is not uncommon in ordinary lung cancer patients undergoing surgery, with previous studies reporting incidence rates ranging from 4.5% to 13.9%. ³ Balancing the benefits of extended pharmacological thromboprophylaxis for these surgical patients with drawbacks like bleeding risks requires careful consideration of individual patient characteristics and preferences. Previous research has highlighted factors such as immobilization, being bedridden, having central venous catheters, experiencing sepsis, using sedative or anesthetic drugs, prolonged surgical duration, reliance on mechanical ventilation, elevated D‐dimer level, age exceeding 60 years, receiving more extensive surgical procedures than lobectomy, and reaching stage IV of lung cancer as contributors to the development of VTE in patients undergoing thoracic surgery for lung cancer. ³ Therefore, we also advocate for a nuanced risk assessment considering multiple predictors. This approach aims to strike a balance by appropriately addressing the needs of high‐risk patients while avoiding unnecessary pharmacological thromboprophylaxis for those at lower risk.

VTE development stems from simultaneous factors, some reversible (e.g., surgery, trauma) and others persistent or irreversible (e.g., cancer, antiphospholipid syndrome). ⁴ Some healthcare decision‐makers advocate a comprehensive cost‐effectiveness analysis of extended thromboprophylaxis, factoring in potential savings from preventing VTE‐related complications. Clinically, there are pharmacological and mechanical thromboprophylaxis strategies for patients with high VTE risk. However, the authoritative National Comprehensive Cancer Network (NCCN) guidelines on cancer‐associated VTE do not specifically address the issue of lung cancer. In contrast, they only recommend mechanical thromboprophylaxis for the risk with contraindications to the pharmacologic method. ³

We strongly recommend appropriate thromboprophylaxis when the “thrombosis threshold” is exceeded by the cumulative impact of acquired and genetic risk factors for symptomatic and asymptomatic patients. Maintaining a heightened awareness of each patient's risk, rather than rigidly adhering to local guidelines, is currently the most cost‐effective and practical strategy to prevent life‐threatening VTE.