A prechemotherapy platelet count ≥350,000/mm³ was significantly associated with an increased risk of venous thromboembolism compared to <200,000/mm³ (adjusted OR 2.81; 95% CI 1.63-4.93; P=0.0002).
Observational (n=3,003)
Yes
What are the risk factors for venous thromboembolism in ambulatory cancer patients initiating chemotherapy?
Elevated prechemotherapy platelet count, specific cancer sites, and low hemoglobin are significant risk factors for VTE in ambulatory cancer patients starting chemotherapy.
Effect estimate: adjusted OR 2.81 (95% CI 1.63-4.93)
Absolute Event Rate: 3.98% vs 1.25%
p-value: p=0.0002
BACKGROUND: The incidence of venous thromboembolism (VTE) is increased in cancer, but little information is available about risk factors in cancer patients on chemotherapy. METHODS: We analyzed data from a prospective, multicenter observational study to determine the frequency and risk factors for VTE in ambulatory cancer patients initiating a new chemotherapy regimen. The association of VTE with clinical variables was characterized using univariate and multivariate analysis. RESULTS: Among 3003 patients treated with at least one cycle of chemotherapy, VTE occurred in 58 (1.93%) over a median follow-up of 2.4 months (0.8%/mo). The incidence varied significantly by site of cancer (P = 0.01) with highest rates in upper gastrointestinal (2.3%/mo) and lung cancer (1.2%/mo), and lymphoma (1.1%/mo). An elevated prechemotherapy platelet count was significantly associated with an increased rate of VTE (P for trend = 0.005). The incidence of VTE was 3.98% (1.66%/mo) for patients with a prechemotherapy platelet count > or = 350,000, compared with 1.25% (0.52%/mo) for patients with platelet counts of or = 350,000/mm(3) (adjusted OR 2.81, 95% CI 1.63-4.93, P = 0.0002), site of cancer, hemoglobin < 10 g/dL or use of erythropoietin, and use of white cell growth factors in high-risk sites of cancer were significantly associated with VTE. CONCLUSIONS: Symptomatic VTE is a frequent complication of chemotherapy. The prechemotherapy platelet count is a unique risk factor and can help identify high-risk patients for future trials of thromboprophylaxis.
Khorana et al. (Sun,) conducted a observational in Cancer patients on chemotherapy (n=3,003). Prechemotherapy platelet count ≥ 350,000/mm³ vs. Prechemotherapy platelet count < 200,000/mm³ was evaluated on Venous thromboembolism (VTE) (adjusted OR 2.81, 95% CI 1.63-4.93, p=0.0002). A prechemotherapy platelet count ≥350,000/mm³ was significantly associated with an increased risk of venous thromboembolism compared to <200,000/mm³ (adjusted OR 2.81; 95% CI 1.63-4.93; P=0.0002).