Cerebral neoplasms are anomalous masses of tissue in the brain due to an abnormal proliferation of cells that can be malignant or benign. They can be classified as primary or secondary (metastatic).
No underlying cause is identified for the majority of primary brain tumors. Current known risk factors include exposure to ionizing radiation, immunosuppression, and toxins. At this time there is no clear evidence that cell phone usage or exposure to electromagnetic/radiofrequency radiation usage correlates with development of cerebral neoplasms. There are ongoing studies to examine this association; however, current data does not support the relationship.
Epidemiology including risk factors and primary prevention
The National Cancer Institute estimates that there are more than 23000 new diagnoses of brain and nervous system cancers causing more than 14,000 deaths each year in the United States.
Incidence rates are higher in industrialized countries with men having slightly higher rates than women. Glial tumors comprise about 60% of primary brain tumors, and 80% of those are malignant. Meningiomas are next most common, followed by schwannomas and lymphomas. Those with the human immunodeficiency virus, autoimmune disorders, and individuals who are status post-transplant are at an increased risk for cerebral lymphoma. Brain metastases are more common than primary brain tumors. Common sites of metastases are lung, colon, breast, kidney, and skin (melanoma). Eighty percent of brain metastases occur in the cerebral hemispheres, 15% in the cerebellum, and 5% in the brainstem.
Cerebral neoplasms can be primary or metastatic. The World Health Organization (WHO) classifies primary brain tumors as:
Tumors of neuroepithelial origin – These include tumors of neurons and glial cells (astrocytomas and oligiodendrocytes).
- Oligiodendrocytomas: These tumors account for less than 10% of primary central nervous system (CNS) tumors and are typically sensitive to chemotherapy.
- Astrocytomas: WHO guidelines outline 4 grades, with Glioblastoma multiforme (GBM) being notoriously aggressive. GBM is the most common type of primary CNS neoplasm.
Tumors of meninges – Meningiomas are usually benign but may be malignant.
Lymphomas and hematological tumors ‑ CNS lymphomas account for 2% to 3% of tumors.
Tumors of the sellar region ‑ These include pituitary adenoma and craniopharyngioma.
Disease progression including natural history, disease phases or stages, disease trajectory (clinical features and presentation over time)
Grading and staging of tumors is specific for tumor types. Grading of tumors is used to provide prognostication. A standardized grading system developed by the WHO is listed below:
- Grade I: The tissue is benign. The cells look nearly like normal brain cells, and they grow slowly.
- Grade II: The tissue is malignant. The cells look less like normal cells than the cells in a grade I tumor.
- Grade III: The malignant tissue has cells that look very different from normal cells. The abnormal cells are actively growing and have a distinctly abnormal appearance (anaplastic).
- Grade IV: The malignant tissue has cells that look most abnormal and tend to grow quickly.
The prognosis will be determined by tumor type and tumor grade. In general GBM has the most grave prognosis with median survival of about 1 year depending on age, tumor size, and extent of surgical resection.
Specific secondary or associated conditions and complications
Surgical intervention can have potential complications, including infection, delayed wound healing, and pain at the surgical site.
Radiation effects are varied depending on the type of radiation used. There are a myriad of radiation-induced side effects including nausea, fatigue, cognitive impairment, skin changes, and nerve injury.
Chemotherapy side effects have reduced with newer agents but are still significant. Nausea and vomiting are the most commonly reported symptoms; thrombocytopenia and neutropenia are also common.
2. ESSENTIALS OF ASSESSMENT
The presentation can be varied. Symptoms may be generalized due to increased intracranial pressure (headache with nausea or vomiting, personality changes, impaired gait) or focal. Focal presentations depend on the site of the tumor and can include hemiparesis, visual field defects, or speech impairment. Seizures are common and have a focal onset, though that may not always be apparent clinically.
Differential diagnosis includes stroke, epilepsy, abscess, and hydrocephalus. History should include onset, associated symptoms, and inquiry about risk factors.
A physical exam may help determine localization. Weakness, sensory abnormalities, and cognitive impairment may be found. The clinician must perform a careful, comprehensive neurologic examination including cognitive and speech testing, eye movements, vision, hearing, smell, and balance/coordination. General physical examination may provide clues to a possible primary site for metastatic brain tumors.
Functional assessment should evaluate effects of the disease as well as those of cancer treatment. This should include assessment of pain, fatigue, seizures, neurologic impairments, and psychological status and the effects of impairments in the areas on cognitive functioning, mobility, self-care, safety, and general well-being.
Laboratory studies may provide clues to the site for metastatic brain tumors or help detect and monitor secondary conditions and complications.
Magnetic resonance imaging (MRI) is the preferred modality for tumor characterization via T1 and T2 weighted imaging and should be performed with gadolinium contrast. Malignant brain tumors often enhance with gadolinium and may have central necrosis and surrounding edema. Other imaging studies including positron emission tomography (PET) scans, magnetic resonance spectroscopy (MRS), and computed tomorgraphy (CT) angiography may aid in diagnosis and treatment. CT imaging with contrast may reveal a mass with surrounding vasogenic edema if the MRI is not feasible.
Specific testing may also be warranted based on symptoms and exam findings: these include audiology for acoustic neuroma, lumbar puncture for abnormal tumor cells, endocrine workup for hormonal abnormalities, and electroencephalogram for suspected seizure activity.
Supplemental assessment tools
In addition to the widely used Functional Independence Measure (FIM), the Karnofsky Performance Scale is a cancer-specific scale used to classify the individual’s ability to carry out daily activities. The scale is a 0 to 100 scale in which 100 indicates no disease effects, 50 indicates a requirement for help and frequent medical care, and 10 indicates rapidly progressive fatal disease.
The Eastern Cooperative Oncology Group Scale is also commonly used to describe functional ability. It is a 0 to 5 scale in which 0 represents the patient being asymptomatic and 5 represents death.
The above scales are based on observation and do not include patient perceptions of functional status. In addition, they do not incorporate cognitive functioning.
The Cancer Rehabilitation Evaluation System (CARES) is another tool which measures quality of life. This tool is noted to have good reliability and validity and is available in long and short forms.
Neuropsychological evaluation can be used to assess and monitor “chemobrain” or Cancer and Treatment-Related Neurocognitive Degneration (CRND).
Early predictions of outcomes
Prognosis may be determined by clinical and pathological staging of the tumor, and knowledge of the typical course of the specific type of tumor. The physiological reserve of the patient is also important in determining outcome.
An assessment of the living environment may be helpful in planning management of fatigue, pain, and cognitive or motor impairments. Seizures may raise safety concerns and affect the patient’s ability to drive.
Social role and social support system
A plan and goal for treatment is best determined via communication with the patient, family, and team. An assessment of the patient’s support system and life role is important in formulating a management plan. Treatment options should be outlined with reasonable goals outlined. The importance of providing support in the form of psychological support, counseling, palliative, and symptom management cannot be understated.
It is important to listen to the patient’s wishes and not to provide false hope. Rehabilitation units can be ideal locations for achieving functional gains prior to discharge home, even for patients with advanced disease. Hospice programs focus specifically on end of life care in addition to palliative measures.
3. REHABILITATION MANAGEMENT AND TREATMENTS
At different disease stages
Open communication is important for appropriate counseling of patients who may opt for unproven treatments because of the lack of response to conventional therapies.
Treatment for cerebral tumors will be dependent on tumor type and grade and will be influenced by symptoms and goals. Treatment addresses the effects of the disease as well as side effects of cancer therapies. Rehabilitation in the cancer patient has several phases, from diagnosis and the treatment planning phase to the terminal phase in those with fatal disease.
Definitive treatments are based on the tumor type and extent. Many current medical and surgical therapies for cerebral tumors focus on resection in conjunction with radiation therapy. Chemotherapy may also be used for specific cancer types. Glucocorticoids, such as dexamethasone, are administered to reduce cerebral edema and may significantly improve neurologic function. There are a variety of antinausea medications which can be given with chemotherapy to help limit nausea and vomiting. Serotonin antagonists have become more widely used and are frequently combined with steroids to prevent nausea. Venous thrombo-embolism is common, so anticoagulant prophylaxis should be considered in nonambulatory patients. Reversible causes of symptoms should be sought and treated.
Coordination of care
Rehabilitation treatments are individualized for the patient. Rehabilitation specialists should be part of a multidisciplinary team that may include oncologists, neurosurgeons, neurologists, and others, as appropriate. Treatments should address cognitive/communication strategies, emotional and behavioral aspects, as well as physical functioning. Appropriate therapies should be initiated to address effects of the neoplasm on speech, cognition, vision, strength, balance, coordination, or gait. Memory, concentration, and processing speed may affect rehabilitation strategies. Fatigue may require incorporation of energy conservation techniques, adjustment of therapy timings, and addressing sleep impairment. Nutritional impairments should be addressed. Pain control is important and may require use of opioid analgesia. Spasticity may benefit from neurolytic procedures. Antiepileptic medications are indicated for seizure onset, though routine prophylaxis is not indicated in the absence of seizure activity. Counseling and supportive communication of the patient and family may help reduce anxiety and depression.
Patient & family education
Quality of life issues must be addressed in addition to maximizing cognitive and physical function. The rehabilitation medicine physician is equipped to address these issues via supportive care and pain control at all stages of cancer treatment in concert with other treating specialists. This includes not only care of the patient, but addressing family concerns and providing education.
Imaging is required to assess the response to cancer treatment and evidence of a complete or partial response or of disease progression. Functional scales such as the Karnofsky Performance Index or the FIM can be used to document effect of treatment on functional capability and outcome.
Use of advanced imaging techniques, such as tractography may help in limiting functional damage incurred during surgical resection.
Translation into practice: practice “pearls”/performance improvement in practice (PIPs)/changes in clinical practice behaviors and skills
New symptoms should be assessed for potential reversibility instead of automatically attributing them to tumor progression.
4. CUTTING EDGE/EMERGING AND UNIQUE CONCEPTS AND PRACTICE
Cutting edge concepts and practice
Emerging knowledge of biological features of specific neoplasms may yield new treatment options. Immunotheraputic agents are in clinical trials and allow the body’s inherent immune system to reduce the tumor burden.
5. GAPS IN THE EVIDENCE-BASED KNOWLEDGE
Gaps in the evidence-based knowledge
There is a need for well designed studies todemonstrate the role and value of rehabilitation in the care ofpatientswith cerebral neoplasms.
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Original Version of Topic
Christian Shenouda, MD. Cerebral Neoplasms. 11/16/2011.
CHRISTIAN SHENOUDA, MD
Author indicated he/she has no relevant financial relationships to disclose.