BackgroundLong-term survivors of childhood-onset brain tumours have increased mortality rates, even after excluding deaths related to recurrence or regression of the original tumour. In particular, there is an increased risk of premature vascular disease by mechanisms that remain unclear. We tested our hypothesis that a thrombotic fibrin network profile is one mechanism for the increased vascular risk in this population. MethodsWe undertook a cross-sectional study in 33 patients (19 men, mean age 31·5 years [SD 14·2]) with previous history of primary brain tumours of either childhood or adulthood onset and 33 age-matched and sex-matched healthy controls. We performed clot structure analysis using a validated turbidimetric assay and also assessed plasma concentrations of thrombotic and inflammatory vascular markers including fibrinogen, C-reactive protein (CRP), and complement C3. The mean time from brain tumour diagnosis to the time of the study was 8·9 years (SD 6·2). FindingsAll patients had cranial radiotherapy, whereas 25 (76%) and 13 (39%) had additional surgery and chemotherapy, respectively. 31 patients (94%) had growth hormone deficiency, five (15%) had deficiences in luteinising hormone and follicle-stimulating hormone, four (12%) in adrenocorticotropic hormone, and two (6%) in thyroid-stimulating hormone. Patients had raised clot maximum absorbance (a measure of clot density) compared with controls (mean 0·412 arbritary units [SD 0·10] vs 0·277 [0·09], p<0·0001), increased clot lysis time (an indicator of fibrinolysis potential) (3695 s [731] vs 2720 [636], p<0·0001), and larger lysis area (a complex measure of clot formation time, clot density, and lysis potential) (1949 arbitrary units [1390] vs 906 [704], p<0·0001). Despite differences in fibrin network characteristics, fibrinogen concentrations were similar in patients and controls. Plasma CRP was higher in patients than in controls (3·08 mg/L [4·25] vs 0·78 [1·08], p=0·006) with similar findings for C3 (0·75 mg/mL [0·13] vs 0·67 [0·13], p=0·027). InterpretationWe demonstrate, for the first time to our knowledge, that survivors of brain tumours with hypopituitarism display a thrombotic fibrin network profile, providing one mechanism for the increased vascular risk in this population. These changes are not related to altered fibrinogen concentrations suggesting that other plasma proteins or qualitative changes in the proteins might contribute to the observed differences. Further longitudinal studies are required to clarify whether optimisation of the hormonal profile results in amelioration of the thrombotic environment in this population. FundingPfizer (investigator-initiated research grant).
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