Epidemiological features of meningiomas: a single Brazilian center's experience with 993 cases / Características epidemiológicas de meningiomas: experiência de um centro único brasileiro com 993 casos

ABSTRACT

ABSTRACT Background: Meningiomas are the most frequent primary central nervous system (CNS) tumors. Their geographical and ethnic characteristics need to be known, in order to enable rational treatment. Objective: To investigate clinical and epidemiological aspects in a series of patients with meningiomas. Methods: Retrospective analysis on the demographic profile, location and histopathology of 993 patients with meningiomas (768 operated and 225 not operated). Results: Meningiomas represented 43.8% of the primary CNS tumors; 6.8% were multiple tumors (14.7% with neurofibromatosis 2) and 0.6% were radiation-induced tumors. The mean ages were 53.0 and 63.9 years for operated and non-operated patients and the female/male ratios were 3.21 and 6.31. Diagnosis was made later among females. The peak incidences were in the 6th and 7th decades respectively for operated and non-operated patients. The incidence was low at early ages and higher among patients aged 70+ years. The meningiomas were intracranial in 96.5% and most were WHO grade I (88.9%) and transitional. In the spinal canal (3.5%), they occurred mainly in the dorsal region (all grade I; mostly transitional). The racial distribution was 1.0% in Asian-Brazilians, 87% in Caucasians and 12% in African-Brazilians. 83.4% and 51.6% of the patients were estimated to be recurrence-free at 10 and 20 years, and the mortality rate was 3%. Conclusions: Most of the demographic data were similar to what has been observed in other western centers. Differences were higher incidence of meningiomas, female and older predominance in non-operated patients, predominance in Caucasian, and higher association with neurofibromatosis 2.

RESUMO

RESUMO Antecedentes Meningiomas são os tumores mais frequentes do sistema nervoso central (SNC). Suas características étnicas e geográficas precisam ser conhecidas para o seu tratamento racional. Objetivo: Investigar aspectos clínicos e epidemiológicos de uma série de pacientes com meningiomas. Métodos: Análise retrospectiva demográfica de 993 pacientes com meningiomas (768 operados e 225 tratados conservadoramente) Resultados: Meningiomas constituíram 43.8% dos tumores primários do SNC. 0.8% deles eram múltiplos (14,7% com neurofibromatose 2) e 0,6% eram radioinduzidos. A idade média e o índice mulheres/homens foram respectivamente 53,0 e 63,9 anos e 3.21 e 6.31 para pacientes operados e não operados. O diagnóstico foi mais tardio em mulheres. Ocorreram picos de incidências na 6ª e na 7ª décadas respectivamente para pacientes operados e não operados. A incidência foi menor na infância e maior após 70 anos. Meningiomas predominaram no crânio (96.5%), a maioria grau I da OMS, subtipo transicional. Do total, 3.5% ocorreram no canal raquídeo, principalmente na região torácica, todos grau I, a maioria transicional. Em relação à distribuição racial, 1.0% dos meningiomas ocorreu em amarelos, 87% em brancos e 12% em negros. As taxas de sobrevida sem recorrência foram 83.4% e 51.6% em 10 e 20 anos e a mortalidade operatória foi 3%. Conclusões: A maioria dos dados demográficos observados foi similar aos de outros centros ocidentais. As diferenças observadas foram maior incidência, predominância em mulheres e idosos nos pacientes não operados e em caucasianos, e maior associação com neurofibromatose 2.