Myeloproliferative neoplasms (MPNs) are types of blood cancers that involve an increase in the number of red blood cells, clotting cells (platelets) or support cells (fibroblasts) due to alterations in the genes of the original cells in the bone marrow. The result is an increase in the risk of blood clots, resulting in blockages in the brain (stroke), heart (myocardial infarction) and other parts of the body. These are termed thromboembolic events. Depending on other factors that patients have, they may be high risk or low risk for these events.
In the UK, the responsibility of targeting prevention and treatment of thromboembolic events is usually placed in the hands of general practitioners (GPs). GPs may start medications that prevent blood clots and treat other factors that may cause thromboembolic events, including high blood pressure, uncontrolled blood sugar, elevated cholesterol profile, and smoking.
This study seeks to understand how many patients in the UK have MPNs, along with how many of them are classified as high and low risk for thromboembolic events. We would also like to know how many thromboembolic events happen among patients with MPNs. We would then determine how many receive different kinds of treatment and preventive measures from their GPs.
With this study, we hope to influence public policy to treat and prevent thromboembolic events among patients with MPN in the UK.
MPNs are a group of neoplasms where there is proliferation of specific blood cell lines, including erythrocytes (polycythaemia vera or PV), platelets (essential thrombocythaemia or ET) or marrow fibroblasts (myelofibrosis or MF). The aetiology of MPNs is still to be fully elucidated and may be related to previous chemotherapy for a primary malignancy, or the occurrence of mutations in the progenitor cells of those blood cell lines resulting in increased cell production.
Because of the massive increase in cell mass within the circulation, there is an increased risk of blood cell shear stress resulting in clumping and clot formation. These thromboembolic events mimic conditions which also result in arterial vascular occlusions, including stroke and myocardial infarction. In MPNs, there is also an increased risk in venous occlusions, resulting in splenic vein thrombosis, cerebral sinus thrombosis and other similar conditions.
As the risk factors for traditional cardiovascular conditions are managed at a primary care level, GPs are increasingly burdened with the care of MPNs despite disease complexity and the need for speciality care. These risk factors include smoking, hypertension, hyperglycaemia and diabetes, and dyslipidaemia.
Our study would like to first assess the epidemiological burden that MPNs and their PV, ET and MF subtypes impose in the UK through a descriptive retrospective single cohort study using CPRD, a clinical dataset for primary care. We would then determine their risk factor profile and demographic characteristics. In order to further elucidate the clinical pathway, we plan to measure thromboembolic events occurring after the diagnosis of MPNs or their subtypes. Finally, we would like to determine whether treatment for risk factors for thromboembolic events was initiated by GPs.
Through our study we hope to gain a clearer understanding of MPNs in the UK and how clinical pathways in primary care can better serve afflicted patients.
Epidemiologic measures (incidence of MPN and its subtypes polycythaemia vera (PV), essential thrombocythaemia (ET) and myelofibrosis (MF), incidence of secondary MF or acute leukaemia, incidence of any other malignancies) mean time to secondary malignancy from MPN diagnosis, demographics and clinical profile (age, sex, ethnicity, index of multiple deprivation, Charlson co-morbidity score, Q risk score, smoking ,dyslipidaemia, hypertension, diabetes, obesity, ischaemic heart disease, peripheral vascular disease, pre-diagnosis thrombosis, blood cell counts), clinical measurements (body mass index, cholesterol level, blood pressure level), clinical outcomes (myocardial infarction, stroke, peripheral arterial disease, deep vein thrombosis, pulmonary embolism, splanchnic vascular thrombosis, rare site venous thrombosis, migraine, vascular dementia, erythromelalgia)
Adrian Paul J. Rabe - Chief Investigator - Health iQ Ltd ( UK ) t/a CorEvitas
Adrian Paul J. Rabe - Corresponding Applicant - Health iQ Ltd ( UK ) t/a CorEvitas
Gulsah Akin Unal - Collaborator - Health iQ Ltd ( UK ) t/a CorEvitas
Gulum Alamgir - Collaborator - Health iQ Ltd ( UK ) t/a CorEvitas
James Tilbury - Collaborator - Health iQ Ltd ( UK ) t/a CorEvitas
Jay Were - Collaborator - Health iQ Ltd ( UK ) t/a CorEvitas
Gulsah Akin Unal - Collaborator - Health iQ Ltd ( UK ) t/a CorEvitas
ONS Death Registration Data;Patient Level Index of Multiple Deprivation