Introduction

In the last few decades, a change in patient populations has occurred. With advancing health care technology and improvements in public health, human societies are aging. It is estimated that in 2020 a fourth of the European population will be in the elderly age range. In the United States one of five persons will be 65 years of age or older by the year 2050, and this population can expect a mean of 17 additional years of life once the age of 65 years is reached.1

The incidence of meningiomas increases with age. Combined with a greater ease of diagnosis, with widely and readily available computed tomography (CT) and magnetic resonance imaging (MRI), this aging patient population is having incidental meningiomas identified more than at any time before. With improvements in neuroanesthesia, neurosurgical technique, intensive care, radiosurgery, and modern radiotherapy planning, treatment of these meningiomas is safer than ever and much more easily tolerated today. All these changes have led neurosurgeons to reconsider the questions of when to treat, whom to treat, how to treat, and what to expect when dealing with a meningioma in an elderly patient.

Several studies have been published on meningiomas in the elderly, and several thousand cases have been reported so far in the literature. However, there are still no clear clinical guidelines for everyday practice.

Initial publications reported dismal outcomes for elderly patients after meningioma surgery.2,3 However, a review of the recent literature indicates that this risk is not as pronounced as it was ( Table 9.1 ). More careful attention is being paid to subgroup analysis among elderly meningioma patients to identify those patients likely to benefit most from surgical intervention and conversely those at highest surgical risk.

Definition of the Elderly Population

Although age greater than or equal to 65 years is widely accepted as the standard definition of the elderly population, there is no specific definition of an elderly meningioma patient. Studies have taken 60, 65, 70, 80, or 90 years as their point of dichotomization, which complicates a simple comparison among them ( Table 9.1 ). One of the earliest studies on the subject was published by Papo.3 The authors grouped their patients into those younger than 60 years, 61 to 65 years, 66 to 70 years, and older than 70 years. Their analysis indicated that the chance of a good outcome decreased from 75% in those patients less than 60 years of age to 71%, 41%, and 13% in the subgroups of incrementally increasing age. The percentage of meningioma patients over 60 years of age rose in that study from 26% to 43% and that of patients over 70 years from 5% to 12% after CT became available.

The Incidence of Meningiomas in the Elderly Population

Along with malignant gliomas, meningiomas are the most common intracranial tumor encountered in the elderly population.4 Meningiomas in the elderly may be symptomatic or they may be found incidentally. Hospital-based studies indicate that the peak of meningioma incidence is in the sixth to seventh decades.5 This may be biased by the fact that meningiomas may more commonly remain asymptomatic in the elderly. Both the incidence and the prevalence of meningiomas steadily increase with age to reach a peak at the eighth decade.6–11 Population-based studies give a clearer picture on the incidence of intracranial tumors when compared with reports form surgical centers. Kuratsu et al9 reported 504 meningioma cases diagnosed in the Kumamoto prefecture in Japan; 38.9% of the cases were incidental meningiomas and 31.7% of all meningiomas were found in patients older than 70 years. Elderly patients made up 26.2% of all symptomatic individuals and 40.3% of individuals with incidental meningiomas. Bateman et al12 analyzed 8861 patients from the U.S. Nationwide Inpatient Sample Database who underwent surgery for intracranial meningioma and found that patients older than 70 years constituted 26% of this population.

The incidence of asymptomatic, incidental meningiomas in the general population ranges from 1 to 1.4% in noninvasive imaging studies in the general population11,13 and in autopsy series.13–15 Rengachary and Suskind16 report an incidence of 4.6% for intracranial meningiomas incidentally found at autopsy in subjects older than 80 years. Similarly, the incidence of meningiomas that come to clinical attention is reported to be 3.5 times higher in patients over the age of 70.5 The prevalence in cases over 60 years of age is 3%.14 Vernooij et al11 have performed MRI on 2000 subjects in a population-based study and found that the incidence of meningiomas at 45 to 59 years was 0.5%, at 60 to 74 years 1%, and at 75 to 97 years 1.6%. Longer life expectancy and increased availability of diagnostic imaging have certainly contributed to a more common diagnosis of meningioma in the elderly.