Older patients with central nervous system (CNS) disease present a unique set of problems for the health care provider. Often their presentation can be atypical, potentially confounding or delaying the correct diagnosis. For example, older patients often present with cognitive dysfunction suggesting dementia, or personality changes suggesting depression rather than more typical symptoms such as headache. This population also has various comorbidities, which often complicate the potential for neurosurgery. Additionally, this group of patients may have a tendency to tolerate radiation, chemotherapy, or supportive agents (such as steroids or antiepileptics) poorly. Also, CNS tumors in general carry with them a significant risk of morbidity and mortality, independent of the patient's age, which may only further complicate the decision making process in the older adult patient. In this chapter, various intracranial neoplastic disease processes and their management in the older adult are considered.
Low-grade gliomas (i.e., astrocytomas and oligodendrogliomas) are relatively uncommon in patients older than 65 years. Therapy usually involves maximally feasible resection. Radiation therapy (RT) may be reserved for symptomatic patients, or patients with recurrent disease. In a randomized European trial, RT did not improve overall survival, but did improve progression free survival. Another indication for RT relates to a patient for whom minimal disease progression might result in significant neurological deterioration. It should be noted that low-grade oligodendrogliomas with chromosomal deletions in the 1p and 19q loci are very sensitive to both radiation and chemotherapy. This enhanced sensitivity to therapy is also true for anaplastic oligodendroglioma (discussed below).
Grade 3 astrocytomas, as well as anaplastic oligodendroglioma, are also less common in older patients with a peak incidence in adults during the third decade of life. The mainstay of therapy is surgery and RT. The definitive role for chemotherapy is yet to be defined in these diseases. By extrapolation from the success of temozolomide chemotherapy (TMZ) in the treatment of newly diagnosed grade 4 astrocytoma (i.e., glioblastoma multiforme [GBM, discussed below]), some oncologists feel there is a role for TMZ chemotherapy in treating these patients at the time of diagnosis. There are, however, no level one data to support this therapeutic approach currently.
Geriatric patients have an increasing incidence of GBM. This diagnosis in a geriatric patient population is typically associated with shorter survivals (than comparable patients who are younger) and may not be treated as aggressively (Table 99-2). Reasons for this may include the “biology” of primary GBM in these patients, comorbidities, and the inability to tolerate toxic therapies. Elderly patients with GBM appear to be less responsive to chemotherapy, and age appears to have a negative correlation with the tumor's response to treatment and time to disease progression, but a positive correlation with toxicity for patients older than 60 years (Table 99-1). Several ...