A Pilot Quality Improvement Initiative for Implementation of Venous Thromboembolism Prophylaxis for Patients with Gastrointestinal Malignancy

Introduction
Cancer associated thrombosis is a leading cause of mortality and morbidity in cancer patients. Khorana score (KS) is one of the most widely used validated clinical scoring tools to predict risk of venous thromboembolism (VTE) in cancer patients starting chemotherapy. Several guidelines recommend assessing VTE risk in all ambulatory cancer patients and considering prophylactic anticoagulation in patients with intermediate and high risk for VTE based on KS. NCCN recommends considering anticoagulation prophylaxis in intermediate and high- risk individuals. Patients who are diagnosed with a gastrointestinal (GI) malignancy are at a particularly elevated risk for VTE development. Despite this, pharmacologic VTE prophylaxis is not routinely used in clinical practice.

Methods
A retrospective chart review of 666 new patients visiting the GI oncology clinic at Inova Schar cancer institute over a period of 1 year – January – December 2023 was done to assess incidence of VTE and validate KS and to understand current utilization of VTE prophylaxis. We identified patients with diagnosis of esophageal, gastric, hepatocellular, pancreaticobiliary or colorectal cancer who were initiated on systemic anti-neoplastic therapy. We excluded patients who were already on therapeutic anticoagulation. Demographic information, diagnosis and stage of cancer and variables involved in assessing KS was collected. We further classified these patients based on the KS. We followed up these patients for a 6-month period from initiation of systemic therapy to see if they developed VTE during this period.

We conducted an online survey among our oncology providers to understand knowledge gap and barriers for VTE risk assessment and use of pharmacologic prophylaxis.

Interdisciplinary meetings including oncologists, hematologists, APPs and pharmacists were conducted to identify and develop strategies to improve implementation of thromboprophylaxis in GI oncology patients.

Results

Our results for the period for January – December 2023 identified 242 (out of 666) patients who met the above criteria. Assessment of VTE risk using KS showed 120 patients (~49%) had low risk, 95 patients (~39%) had intermediate risk and 27 patients (~11%) had high risk for thrombosis. Among the intermediate and high-risk patients, none were on prophylactic anticoagulation. At 6 month follow up, of the 27 patients who had a high-risk KS, 10 developed VTE (~37%), 22/95 (~23%) developed VTE in the intermediate risk group, and 7/120 (~5%) developed VTE in the low-risk group. The two most common locations for VTE development were deep venous thrombosis in extremities and pulmonary embolism.

The survey results showed 75% of responders were familiar with the NCCN guidelines on VTE prophylaxis in cancer patients. 50% of responders indicated familiarity with the Khorana score, but rarely used it in practice. 60% of responders reported never starting VTE prophylaxis prior to systemic therapy, and cited concern for bleeding, polypharmacy, cost and time constraints as barriers to initiation of prophylactic anticoagulation.

The multidisciplinary meetings identified and developed the following strategies: standardized institutional algorithm to implement VTE awareness and prevention strategies, incorporating an electronic medical record tool to calculate real time Khorana score, including VTE risk assessment and discussion as part of clinic note template, educational activities to improve provider awareness, improving patient awareness by providing handouts of cancer associated VTE educational materials and by using visual aids in oncology clinics and cancer center lobby or waiting areas.

Conclusion and Future Directions
We are currently in the implementation phase of this quality improvement initiative. We plan to implement the above steps gradually over a 6-month period at our GI oncology clinic with monthly feedback from the GI oncology team. We will assess the use of prophylactic anticoagulation after about 6 months of full implementation of the program and conduct follow up to assess incidence of VTE post implementation. Our goal will be to eventually extent this project to other oncology clinics as well.