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.