Emerging subspecialties in neurology: neuro-oncology: a developing subspecialty with many opportunities.

Brian Vaillant, MD Sheng-Han Kuo, MD John de Groot, MD NEURO-ONCOLOGY: EXCITING OPPORTUNITIES Neuro-oncology is a unique, developing neurologic subspecialty that combines many aspects of neurology with those of cancer biology. The neurooncologist is expert in both the diagnosis and management of primary brain tumors and neurologic complications of cancer. A career in neuro-oncology presents opportunities to utilize a multidisciplinary team approach and the application of cutting-edge technology toward patient treatment while providing compassionate patient care. Neuro-oncology can trace its modern origins to the 1970s, when the first therapeutic trials were begun. The treatment and management of primary brain tumors is now a rapidly evolving field. The World Health Organization recognizes approximately 100 different types of primary and secondary brain tumors.1,2 Glioblastoma, which is the most common and aggressive type of primary brain tumor, has an incidence of 4 to 5 cases per 100,000. For patients with glioblastoma, life expectancies are measured in months rather than years, with median survival after diagnosis of only 12 to 14 months. In the past, surgical resection and radiation therapy were the main treatment options offered to these patients. In the last several years, studies have shown that chemotherapy provides a significant clinical benefit for patients with malignant brain tumors.3 More recently, molecular markers that predict response to treatment are beginning to be identified in glioblastoma.4 Clinical trials that incorporate biologic endpoints and correlative studies are improving our understanding of the mechanisms of disease and tumor response to treatment. This greater knowledge will lead to the development of more effective agents and individualized treatments based on specific tumor profiles. In addition to glioblastoma, the neuro-oncologist manages less common tumors, including other types of glioma, germ cell tumors, meningiomas, medulloblastomas, and primary CNS lymphomas, and becomes familiar with the cancers’ different biologic and molecular profiles, and treatment approaches. Despite the often poor prognosis of patients with brain and spinal tumors, long-term successes are possible. Patient care focuses not only on improving survival but also on preserving quality of life for these patients and providing support for their families. The neuro-oncologist also specializes in the care of patients with challenging neurologic complications associated with systemic cancers. A common complication of systemic cancer is metastasis to the brain. It is the most common type of brain tumor, with up to 170,000 cases a year in the United States. The neuro-oncologist is proficient in the management of seizures, cerebral edema, stroke, peripheral nerve disorders, and demyelinating disease, which often present unique diagnostic dilemmas and require complex management decisions in patients with cancer. Altered mental status is a common reason for neurologic consultation, and hospitalized patients with cancer usually have multiple causes of delirium, which requires a detailed history and neurologic examination to determine the accurate diagnosis.5 Neuro-oncologists sharpen their skills in lesion localization by observing neurologic deficits in the presurgical and postsurgical setting. This acumen is also vitally important in identifying the early signs and symptoms of spinal and leptomeningeal metastasis. Radiation therapy and chemotherapy can produce a variety of complications involving the nervous system, including strokes, seizures, demyelination, and focal necrosis. The challenging and complex nature of patient care makes neuro-oncology an interesting and exciting subspecialty. Neuro-oncologists plays a unique role by coordinating the care of each patient in collaboration with a wide variety of specialists, including neurosurgeons, radiation oncologists, neuropathologists, psychiatrists, and rehabilitation physicians. In this role, the neuro-oncologist has broad knowledge of these other specialties and the role they play in patient management. In academic settings, tumor boards are a core teaching venue and foster camaraderie and collaboration between neuro-oncologists and other subspecialty groups in an effort to develop