Assessment of Venous Thromboembolism Risk Based on the Khorana Predictive Model and Compliance with Prophylactic Anticoagulation at a Regional Cancer Center- a Quality Improvement Study

Background:

Malignancy is an independent risk factor for venous thromboembolism. Factors like site of the primary cancer, associated comorbidities, obesity, and baseline cytopenias play an important role in predicting the risk in cancer patients. Several risk assessments models have been proposed in the literature, however, the Khorana risk predictive model is the most favored tool used in the literature. Patient characteristics like site of primary, baseline hemoglobin/platelets/WBC and BMI are the main components of this scoring system. Patients are classified into low (0), intermediate (1-2) and high (> 3) risk groups. Low dose prophylactic anticoagulation (Apixaban 2.5 mg BID or Rivaroxaban 10 mg daily) for up to 6 months is indicated in patients with score 2 or higher.

Methods:

83 patients with a new cancer diagnosis in the years 2018 and 2019 who received chemotherapy and developed a venous thromboembolism (VTE) after the cancer diagnosis were identified from the cancer registry at Edwards Comprehensive Cancer Center. All the components of Khorana score including patient's baseline body mass index (BMI), white blood cell count (WBC), hemoglobin, platelet count and site of the primary were collected. Compliance with prophylactic anticoagulation (Khorana score =/>2) was evaluated.

Results:

Among 83 patients identified, 61 % and 39 % were female and males, respectively with a mean age of 59 years. The mean duration of onset of VTE was 18 months from the time of cancer diagnosis. The mean Khorana score was 1.1. 34 % of patients(n=28) were found to have a Khorana score of =/> 2 and prophylactic anticoagulation was indicated. Only 7 % of patients (n=2) received prophylactic anticoagulation. The reason for no prophylactic anticoagulation was not documented in all the cases.

Conclusion:

In patients with a higher risk of VTE, a very low compliance rates for prophylactic anticoagulation were found at our cancer center. Poor documentation and failure to address the risk of VTE are possible reasons for the low compliance rates. Necessary steps needed to improve the compliance rates are warranted including education of the healthcare providers about current available guidelines to decrease risk of VTE in cancer patients. Dedicated lectures and sessions will be organized and educational materials highlighting the importance of VTE risks and prophylactic anticoagulation will be provided to the healthcare providers at the cancer center.