Global trends in survival from brain tumours in adolescents and young adults: a systematic review.

Abstract

Background Brain tumours represent an important cause of cancer-related death in adolescents and young adults. Most are diagnosed in low-income and middle-income countries. We aimed to conduct the first systematic review of time trends and geographical variation in survival in this age group. Methods We included observational studies describing population-based survival from astrocytic tumours in patients aged 15-39 years. We queried six electronic databases from database inception to 30 September 2018. This review is registered with PROSPERO, number CRD42018111981. Results Among 5,245 retrieved records, 20 studies fulfilled the inclusion criteria. Only one study was partly conducted in middle-income countries. Five-year survival from astrocytoma (broad morphology group) varied between 48% and 71% (1973-2004), without clear trends or geographic differences. Adolescents with astrocytoma had better outcomes than young adults, but survival values were similar when non-malignant tumours were excluded. During 2002-2007, five-year survival for WHO grade I-II tumours was in the range 75-93% in England, Germany, and the US, but lower in South-Eastern Europe (59%). Five-year survival for anaplastic astrocytoma varied between 40% and 55% (2002-2007). Five-year survival from glioblastoma was in the range 15-23% (1991-2009). Conclusions Survival from astrocytic tumours remained somewhat steady over time, with little change between 1973 and 2009. Survival disparities were difficult to examine, because nearly all the studies were conducted in affluent countries. Studies often adopted the International Classification of Childhood Cancer, which, however, did not allow to accurately describe variation in survival. Larger studies are warranted, including under-represented populations and providing more recent survival estimates. Keywords Population-based survival, brain tumours, adolescents, young adults, time trends.