Guidelines in Clinical Practice: Appraisal of Quality Metrics in the Management of Newly Diagnosed Diffuse Large B-Cell Lymphoma Based on the American Society of Hematology Practice Improvement Module

Background: The National Comprehensive Cancer Network (NCCN) has issued well-established guidelines for the management and treatment of non-Hodgkin's lymphoma (NHL), in particular for diffuse large B-cell lymphoma (DLBCL). In 2014, the American Society of Hematology established practice improvement module (ASH PIM) incorporating quality metrics in six areas: pathologic diagnosis, staging, hepatitis B testing, use of growth factors, vaccination, and fertility counseling. Currently, such practice improvement modules have allowed physicians to monitor the quality of care in their practice, and reiterating the significance of these clinical guidelines. In an appraisal of quality metrics undertaken at Virginia Mason Medical Center (VMMC), Seattle, Washington, we sought to review four of the ASH PIM metrics and several other metrics to assess adherence to treatment guidelines for Diffuse Large B-Cell Lymphoma (DLBCL) and examine the need for institutional improvement.

Methods: A longitudinal cohort of all patients who were diagnosed with DLBCL and received treatment at VMMC between January 1^st, 2005 to December 31^st, 2016 was identified using VMMC's Tumor Registry. Utilizing the electronic medical records, each patient's chart was reviewed for these quality metrics: pathologic diagnosis, staging of lymphoma, hepatitis and HIV serology testing, echocardiogram (ECHO) prior to starting treatment, clymphoma recurrence risk categorization, chemotherapy education, use of Rituximab therapy, G-CSF use, and post-therapy CT or CT-PET scan. Parameters for pathological diagnosis included assessment of expression of CD20, germinal center vs non-germinal center phenotype based on reporting of MUM1, CD10 and BCL-6, fluorescence in-situ hybridization (FISH) and IHC studies for the presence of traslocation/overexpression of c-Myc, BCL-2 or BCL-6, and EBV assessment by EBV-encoded small RNA1 (EBER1) in-situ hybridization. Staging was evaluated based on imaging in the form of a CT or PET-CT scan prior to treatment initiation and if a bone marrow biopsy (BMB) was also obtained. Serology testing for hepatis B (HBV) and hepatitis C (HCV), and HIV was reviewed. Patients receiving anthracycline-based treatments were assessed for having undergone an ECHOcardiogram prior to initiation of treatment. Post-treatment PET-CT was noted based on the presence of an internal report or outside records.

Results: A total of 179 patients were included in this analysis. The median age of this cohort was 67 years (range 24 -91 years) and 54% of these patients were male. Pre-treatment viral serologic screening was performed in 87% of patients for HBV, 78% for HCVFISH f and 92% for HIV. All the specimen were uniformly tested for expression of CD20, and the germinal center vs. non-germinal center phenotype was determined in 97% of patients. c-Myc and BCL2/BCL6 data was available in only 32% of patients. For staging, all patients had imaging (CT/PET-CT), while bone marrow was obtained in only 72% of patients. Post-treatment imaging was available in 97% of cases. Additional data analysis of treatment-related quality metrics is underway, and shall be presented at the ASH annual meeting.

Conclusion: Performing regular quality assessments by employing standardized metrics provide opportunities to improve the institutional quality of care for patients with newly diagnosed DLBCL, and allows to build and ensure better adherence to evolving NCCN patient-care guidelines ASH PIM. However, performance on the metrics relying on clinical documentation may not be as high as for those relying on objective testing. Whether such quality metrics affect real-time treatment-decisons and patient outcomes needs further evaluation.