Risk factors for venous thromboembolism in older patients with malignant solid tumors: A systematic review.

[INTRODUCTION] We aimed to systematically analyze the risk factors for venous thromboembolism (VTE) in patients aged ≥60 years with malignant solid tumors to facilitate targeted prevention.

[MATERIALS AND METHODS] We searched Ovid MEDLINE, EMBASE, SCIE, and SCOPUS databases for articles from inception to April 24, 2024. Article quality was assessed via the Newcastle-Ottawa Scale, with data extracted independently by two reviewers and thematically categorized.

[RESULTS] Sixteen studies (n = 964,290 patients) were included. VTE incidence varied significantly by cancer type, ranging from 1.2% (prostate cancer) to 20.3% (colorectal cancer). Twenty-nine distinct risk factors were identified across five domains: (1) Treatment-related: chemotherapy (significant risk factor in 8/9 studies), radiotherapy, and targeted therapy. (2) Disease-related: advanced tumor stage (reported in 56% of studies) and high-risk cancer types (pancreatic and colorectal). (3) Comorbidity-related: cardiovascular disease (44% of studies), kidney disease, and a VTE history (strongest predictor, hazard ratio = 5.4-20.1). (4) Sociodemographic: Black race (highest risk), female sex (increased risk for colorectal/renal cancer), and older age. (5) Laboratory: elevated D-dimer level (≥600 μg/L) and low partial pressure of oxygen (<75 mmHg). An "age paradox" was observed: while age is a risk factor, the relative contribution of cancer to VTE diminished with age, and the observed VTE incidence decreased in very old individuals (≥85 years), likely due to competing mortality.

[DISCUSSION] The risk of VTE in older patients with solid tumors is multidimensional. Current risk models are inadequate. Future tools must integrate tumor characteristics, treatment exposures, geriatric-specific factors (comorbidities, frailty), and bleeding risk to optimize personalized thromboprophylaxis.