Adherence to Chronic Myeloid Leukemia Monitoring and Treatment Guidelines in Canadian Registries
Authors: Hillis Christopher M , Busque Lambert , Stakiw Julie , Forrest Donna L. 
Published: October 2019

Abstract
Background: Registry data in chronic myeloid leukemia (CML) complement clinical trial data, and can help determine how closely real world clinical practice adheres to guidelines. Several reports addressing this issue have suggested adherence to monitoring guidelines varies. However, no Canadian data on this topic has been published to date. To provide insight into this issue, we present data from the British Columbia (BC), Saskatchewan (SK), Ontario (ON) and Quebec (QC) CML registries.
Methods: Data on cytogenetic and molecular monitoring were analyzed for CML patients treated with first-line imatinib from 2001-2015 in the BC registry, 2009-2014 in the SK registry and 2001-2014 in the ON registry. From 2006, clinicians in BC and SK were advised to follow the European LeukemiaNet (ELN) monitoring recommendations. Molecular monitoring of BCR-ABL for these provinces was conducted at the BC Cancer Agency Molecular Genetics Laboratory according to standard practices. In ON, clinicians were not advised to follow any particular guidelines and molecular and cytogenetic tests were conducted by the Hamilton Regional Laboratory Medicine Program using contemporary standards. In QC, province-specific guidelines were in place beginning in 2012 (see www.gqr-lmc-nmp.ca for specific guidance). Treatment patterns for patients treated with first-line imatinib from BC, SK and QC were analyzed for the 2001-2015, 2001-2014 and 2002-2012 time periods, respectively.
Results: Monitoring data were collected for 234, 58 and 104 patients from BC, SK and ON, respectively. As shown in table 1, adherence to monitoring recommendations in Canada was 70% to 80% at 12 months. Treatment data were available for 234 BC patients, 73 SK patients, and 223 QC patients. Data on adherence to treatment recommendations were available for 58 SK patients diagnosed with CML and treated with first-line imatinib between 2009 and 2014. Of these 58 patients, over a quarter (n=15) experienced treatment failure or failed to meet ELN milestones without a change in therapy. Smaller proportions of patients receiving first-line imatinib therapy in BC and QC remained on imatinib therapy (see table 2).
Discussion and Conclusions: These data suggest there is room for improvement with regards to adherence to CML monitoring and treatment recommendations in Canada. However, assessment of adherence to recommendations and inter-provincial comparisons are limited by the fact that monitoring and treatment guidelines have evolved over the data collection time period, as well as by differences in data collection strategies. For instance, in the ON registry, monitoring at the 3-month time point may be lower as testing was not typically conducted at 3 months in ON during the early 2000s. The opposite pattern observed in BC (with higher testing rates at 3 months dropping off by 18 months) may be attributable to the strict time period definition, with more patients receiving testing outside of the 4-week window after 1 year or more on treatment. In spite of these limitations, data collection through these registries continues to improve our understanding of real world CML populations and its management in Canada, as well as to spur initiatives aimed at improving CML care.
This study was sponsored by Bristol-Myers Squibb. Professional medical writing and editorial assistance was provided by MedPlan Communications Inc. and was funded by Bristol-Myers Squibb.

Disclosures
Hillis: Novartis: Consultancy, Honoraria, Research Funding, Speakers Bureau; BMS: Honoraria; Celgene: Consultancy. Busque:Novartis: Honoraria, Research Funding, Speakers Bureau; BMS: Honoraria, Speakers Bureau; Pfizer: Honoraria, Speakers Bureau. Stakiw:Roche: Research Funding; BMS: Honoraria; Novartis: Honoraria, Speakers Bureau; Amgen: Honoraria, Speakers Bureau; Celgene: Honoraria, Speakers Bureau; Jansen: Honoraria, Speakers Bureau. Forrest:BMS: Consultancy, Research Funding; Ariad: Honoraria, Speakers Bureau.