Current Standards of Care in Glioblastoma Therapy

Introduction

With an incidence of 3 to 5 per 100,000, glioblastoma fulfills the criteria of a rare cancer. Despite this, glioblastoma is the most common and most aggressive primary brain tumor and accounts for 12% to 15% of all intracranial neoplasms and 45% to 50% of all gliomas. Patients of any age may be affected, but it is most commonly observed in individuals over the age of 50 years. The suspicion of the presence of a glioblastoma is typically raised if a patient presents with neurologic symptoms and an imaging study shows the presence of a suspect lesion. On computed tomography (CT), the lesion typically appears as a contrast-enhancing lesion with peritumoral edema. However, smaller lesions may be missed. MRI is significantly more sensitive than CT and represents the modality of choice. Glioblastoma appears as a heterogeneous enhancing lesion with or without necrotic core. The margins are usually diffuse as a reflection of the infiltrative nature of the lesion. There is typically prominent peritumoral edema.

At present, despite aggressive treatment, the prognosis of glioblastoma remains dismal, with overall an estimated median life expectancy of only 14-16 months following diagnosis. Two-year and 5-year survival rates remain around 30% and 10% respectively. With these outcomes, it is essential to tailor the treatments for each individual patient to offer the best possible outcome with the optimal quality of life.

The initiation of therapy for glioblastoma therefore depends on many factors. These factors include, but are not limited to, the patient’s preoperative level of function, performance status, age, and the resources available to the patient and the treating physicians. This chapter describes the standard of care for newly diagnosed glioblastoma and provides a brief overview of the evidence that supports these treatment paradigms.