2026 Eastern States Conference

Title: Evaluation of guideline-directed venous thromboembolism prophylaxis in high-risk ambulatory cancer patients
Authors: Srivishnu Vardhan Parasaram, PharmD; Julie Shupp, PharmD, BCOP; Jorge Aguilera, PharmD, BCPS
Learning Objective: Audience members will be able to evaluate institutional adherence to NCCN/ASCO guideline-directed venous thromboembolism (VTE) prophylaxis in ambulatory cancer patients.
Background/Objective: Cancer-associated thrombosis is a significant cause of morbidity and mortality in oncology patients. The National Comprehensive Cancer Network (NCCN) and American Society of Clinical Oncology (ASCO) guidelines recommend consideration of VTE prophylaxis for high-risk ambulatory cancer patients initiating systemic chemotherapy, defined by a Khorana Score of 2 or greater. This study aimed to determine the rate of appropriate VTE prophylaxis prescribing at John R. Marsh Cancer Center within Meritus Health and to evaluate associated clinical outcomes.
Methods: This retrospective observational study evaluated adults aged 18 and older presenting with a new cancer diagnosis and initiating chemotherapy at John R. Marsh Cancer Center between January 1, 2024 and December 31, 2024. Baseline Khorana Scores were calculated to stratify VTE risk. Patients were excluded if they were receiving therapeutic anticoagulation for a pre-existing condition (e.g., atrial fibrillation, secondary prophylaxis), had a documented absolute contraindication to anticoagulation, were pregnant, or received treatment exclusively at an outside facility. The primary outcome was the rate of appropriate VTE prophylaxis prescribing based on NCCN guidelines. Secondary outcomes included the incidence of VTE events, major bleeding events, and all-cause mortality, stratified by Khorana Score, management appropriateness, and metastatic status.
Results: A total of 167 patient charts were included for analysis. Guideline-adherent VTE prophylaxis management was observed in 67.1% of patients (n=112), with 55 patients (32.9%) managed inappropriately based on their baseline Khorana Score. Of the entire cohort, only 3 patients (1.8%) were prescribed pharmacologic thromboprophylaxis, reflecting a very low overall prescribing rate despite the high proportion of high-risk patients. VTE events occurred in 9.8% (n=11) of appropriately managed patients compared to 25.5% (n=14) of inappropriately managed patients, a statistically significant difference (p=0.015; RR 2.60, 95% CI 1.27–5.33). Patients with a Khorana Score ≥2 experienced VTE at a rate of 24.6% compared to 10.0% in low-risk patients (p=0.023; RR 2.46, 95% CI 1.19–5.06). Major bleeding events occurred in 3.0% of the overall cohort (n=5); no statistically significant differences were observed across any subgroup, though the analysis was limited by the low event count. All-cause mortality occurred in 24.0% of the cohort (n=40), with significantly higher rates observed in patients with a Khorana Score ≥2 (36.8% vs. 17.3%, p=0.009) and in inappropriately managed patients (38.2% vs. 17.0%, p=0.005).
Conclusion: Adherence to NCCN/ASCO VTE prophylaxis guidelines at our institution was 67.1%, with an overall pharmacologic prophylaxis prescribing rate of only 1.8%, suggesting that guideline-concordant management in this population is largely driven by appropriate withholding of prophylaxis in low-risk patients rather than active prescribing in high-risk patients. Inappropriately managed patients experienced significantly higher rates of VTE, demonstrating the clinical consequences of non-adherence. All-cause mortality differences across subgroups likely reflect underlying cancer burden and disease severity rather than VTE-attributable death, as cause of death was not captured. While provider hesitance regarding anticoagulation is understandable given bleeding risk and potential treatment delays, this study highlights a meaningful quality improvement opportunity. The occurrence of VTE in low-scoring patients and variable outcomes among high-scoring patients also suggest the Khorana Score alone may have limited precision in this population, underscoring the need for prospective evaluation and potentially more individualized risk stratification tools.