Stroke before a haematopoietic stem cell transplantation is a potential risk factor for poor response to therapy in patients with blood cancer

Introduction. More than 50,000 haematopoietic stem cell transplantations (HSCTs) are performed worldwide each year to treat malignant blood cancers, solid tumours, bone marrow aplasia, primary immunodeficiency conditions, autoimmune disorders, and storage disorders. The success of HSCTs depends on many factors, including patient's past medical history. Purpose. To assess the effect of an acute cerebrovascular accident (CVA) that occurred before the HSCT on the transplantation outcome in patients with blood cancer. Materials and methods. We examined the results of 899 transplantations conducted between 2016 and 2018 at the R.M. Gorbacheva Research Institute for Pediatric Oncology, Haematology and Transplantation of the Pavlov First Saint Petersburg State Medical University. We analysed transplantation parameters, as well as donor and recipient characteristics. Apart from intergroup comparisons, pseudo-randomization was performed using the Propensity Score Matching method. The survival rate analysis was conducted using the KaplanMeier estimate and the log rank test. Results. Sixteen patients (1.8%) had cerebrovascular events in their past history before the HSCT: ischaemic stroke in 0.4% of cases and haemorrhagic stroke or intracerebral haemorrhage in 1.4% of cases. Patients with a history of cerebrovascular events included more people with leukaemia (p = 0.02), had more often received an allogenic transplant (р = 0.01), the donors more often had a partial rather than a full HLA match with the recipient (р = 0.06), had a lower body mass index (р = 0.02), and a lower Karnofsky/Lansky score (р = 0.01) than patients in the control group. The presence of a cardiovascular event had a statistically significant association with reduced overall survival rate of HSCT recipients (р = 0.0012). Conclusion. Patients with blood cancer and stroke preceding the transplantation do not typically have any 'classical' risk factors (diabetes mellitus, venous system disorders, decreased cardiac output, significant atherosclerotic changes in precerebral arteries), therefore, secondary prevention guidelines for CVA during treatment of the main disease may not be effective and cannot be relied on. This article discusses the most likely causes of CVA in patients with blood cancer. A history of CVA before HSCT may have a significant effect on the transplantation outcome, but is not a contraindication for this treatment method. Recipient selection is a very important stage in HSCT planning. A multidisciplinary team should find a balance between the indications and contraindications for performing HSCT from an unrelated donor.