Brain Tumors: Epidemiology and Principles of Diagnosis and

Management

Andrew J. Tsung M.D.Patrick W. Elwood Endowed Assistant Professor

Department of NeurosurgeryDirector, Brain Tumor Center and Neurosurgical Research

Illinois Neurological InstituteUniversity of Illinois College of Medicine at Peoria

Continuing Education Provider

OSF Saint Francis Medical Center Continuing Education Provider Program (CEPP) is an approved provider of continuing nursing education by the Illinois Nurses Association, an accredited approver by the American Nurses Credentialing Center’s Commission on Accreditation.

Conflict of Interest

There is no conflict of interest or bias on the part of the presenter.

Objectives• Describe the epidemiology of brain tumors• Categorization of tumors• Brief description of only the most common primary brain tumors• Management of metastatic brain cancer• Familiarity with methods of current diagnosis

– Imaging– Physical Examination

• Options in surgical management– Surgery

• Craniotomy• Stereotactic biopsy

– Radiation• Radiosurgery (single fraction i.e. gamma knife)• Whole brain radiotherapy (multiple fractions/non-conformal)• Fractionated radiotherapy (multiple fractions/conformal)

• Identify complications- surgical and non-surgical• Summary

Primary Concepts• Primary Brain Tumors

– Meningiomas can be treated effectively with gamma knife or surgery

– Glioblastoma is uniformly fatal, but we are making progress, necessitating full evaluation. Aggressive surgery and chemoradiation therapy provides survival benefit. A nihilistic approach is never appropriate regardless of age

– WBRT solely is not the “easy” solution to metastatic brain cancer due to prolonged survival

Epidemiology-Overall Numbers

• Primary brain tumors– 43,000 annually and

13,000 people die– 1.5 million diagnosed

with diabetes in the U.S. alone

• Overall annual incidence in the U.S. is 15/100,000

• Overall annual incidence for primary malignant is 7/100,000

• Brain tumors are increasing dramatically over the past 3 decades (300%)

– Improved diagnostic capabilities (CT/MRI)

– Changing attitudes towards diagnosis in the elderly

– There may be inherent causal factors, especially in children

Epidemiology-Age and Gender

• Gender variation among tumor types– Most significant is

glioma vs meningioma

Epidemiology-Age and Gender

• Overall median age of onset of primary brain tumors is 57

• GBM and meningioma 64/63, respectively

• Most common types of gliomas (GBM and astrocytoma) contribute to the peak observed at ages 75-84

• Meningioma increases continuously with age

Epidemiology-Survival and Prognostic Factors

• Survival has not significantly changed for the last 30 years for patients with glioblastoma multiforme (GBM) –Disagree!!

• Some notable improvements have been reported for medulloblastoma

• Overall, rates vary significantly among different types of tumors

• Histologic type and age are generally the strongest prognostic factors

• Reasons for variation even within histologic subcategory:

– Tumor/molecular markers

• 1p/19q• EGFR amplification• MGMT methylation

Epidemiology-Risk Factors

• Head trauma- meningioma, no link with other tumors

– Subject to recall bias

• Exposures to drugs/medications

– Very few studies• Diet/Vitamins/

Alcohol/Tobaco/Residential Chemicals

– N-nitroso compounds (cured meats)

• Probable but not definite link in a meta-analysis of nine studies suggest a 48% increase in risk

• Smoke all you want (as long as they are filtered)

• Alcohol may give you a subdural when you fall off the barstool, but not a GBM

Epidemiology-Risk Factors• Industry and Occupational Chemicals

– No definite link to a certain chemical• Industries in the Texas petrochemical plants suggested higher malignant brain tumors• Manufacturing of pesticides or fertilizers• Rubber/tire industries• Laboratory scientists

• Ionizing Radiation– Strong link

• Tinea capitis (1.5 Gy) results in relative risk of 18,10, and 3 for nerve sheath tumors, meningioma, and gliomas• Prophylaxis for ALL• Atomic bomb survivors and meningioma

– Parental exposure to radiation prior conception not a risk factor– Prenatal exposure unclear (mostly involve dental xrays and meningioma with increased risk of 1.2-3.0

• Cellular phones and EMF– No definite link

• Most do not show any link• One long-term study (10 years) of cell phone use showed a 2x increased risk for acoustic neuroma (vestibular

schwannoma), when restricted to the ear of use, risk increased 4x• RF frequencies have changed though, analog is 800-900 MHz while digital operates in the range of 1600-2000

MHz– EMF

• 52 studies reviewed, inclusion of 29 studies in a meta-analysis that showed a significant increased risk of 10-20%• San Francisco population based study reviewed 492 patients with glioma who were not more likely than 463

controls to have lived near high wires during 7 years prior to diagnosis• Problem exists that the pertinent exposure period is unknown (as the mechanism of tumorigenesis is unknown)

Epidemiology

• Genetic predispostion-What does this mean? A single gene or multifactorial increased susceptibility?

• Susceptibility implies genetic alterations than influence oxidative metabolism, carcinogen detoxification, DNA stability and repair, immune response, and other aspects of metabolism and cellular function

• Evidence is clear- genetics play a role, but only account for 5-10% of brain tumors

• Hereditary syndromes– Li-Fraumeni syndrome

• First degree relative with cancer 58 vs 42%

• Previous history of cancer 17 vs 8%

Categorization

• World Health Organization of CNS Tumors– 9 Major Categories

• Tumors of neuroepithelial tissue represent a significant portion of primary brain tumors

– “Glioma” often used to refer to glial tumors of any glial lineage but in its usual sense, we mean only astrocytic tumors

Categorization

Common Tumor Types and

Characteristics• Low grade astrocytoma– Histologic Subtypes

• Fibrillary• Protoplasmic• Gemistocytic

– Diagnosis• Majority present with seizures >50%

– Treatment - Controversial• Observation, no difference in survival if surgery is deferred until growth,

transformation, intractable seizures• Resection, gross total or biopsy ± radiation• Favored at Neurosurgical Oncology centers• Radiation- may improve time to progression without survival benefit,

may be delayed until progression is seen– Prognosis

• Median survival 8-12 years• Prognostic factors Age, enhancement, KPS

Patient Example• 20 yo healthy male

presenting with first time GTC seizure, no focal deficit

• Biopsy via awake craniotomy, positive speech arrest at periphery and surgery terminated

• Grade 2 Astrocytoma

• No further adjuvant treatment

Patient Example

August 2007 December 2010

Patient Example

Patient discharged home POD 3No deficit

Pathology Grade 3 Anaplastic AstrocytomaMust now undergo chemo and radiation

Common Tumors

• Anaplastic Astrocytoma and GBM aka “Malignant Glioma”

Common Tumors

• AA/GBM– Median age 60 yo– Seizures in 20%– AA 30%

nonenhancing/GBM 4% nonenhancing

– Treatment• Surgical

resection followed by conformal XRT and concomitant temozolomide (Temodar)

• “Stupp” Protocol Standard of care since 2006

Common Tumors

• AA/GBM

Questions about AA/GBM

• How much does surgery help?– Does “good” surgery help more?

• How much does age affect the outcomes?

• Have we made any progress?

Extent of resection

Extent of resection

Extent of resection

Extent of resection

Progress?

Progress?

Progress?

Pushing the limits• 73 yo male

professor presents with headache only– Mayo Clinic

Neurosurgery refused surgical intervention due to high risk

– Was biopsied only at MC, however too small of specimen taken to enroll in any clinical trials

Pushing the limits– Resected at the

INI and discharged without complication 2 days after surgery

– 95-98% resection– Undergoing

chemoradiation therapy with KPS 80

– Did we do the right thing?

Comparison to other cancers

Median PFS

Comparison to other cancers

Median OS

Common Tumors• Meningioma

– Arise from arachnoid cap cells

– Increases with age• Incidence 0.3/100,000 in

childhood to 8.4/100,000 in elderly population

– Female 2:1– Locations

Parasagital>convexity>sphenoid wing

– May have increased risk with HRT

• Symptoms– Non-focal from increase in

ICP– Seizures (up to 40%)– Localized CN deficit or

compression upon eloquent areas depending on the location of the tumors

– Histologic grades– Grade I/II/III

• Indicate the malignancy and thus the propensity to recur after resection

Common Tumors• Meningioma

– Surgery is the mainstay of treatment for symptomatic patients– Not all need to be treated

• Availability and frequency of scanning results in high numbers of incidental meningiomas (2.3% in autopsy series)

• Commonly thought that they do not grow throughout life and have very low rates of growth (between 0.03 and 2.62 cc/year)

• Elderly show lower growth rates than those in younger people– Asymptomatic tumors are occasionally removed depending on location

• If further growth would result in great difficulty in surgical removal• Have displayed high growth rates on follow-up imaging

– Observation, radiosurgery (gamma knife) or radiation therapy for subtotal resection (approximately 1 in 3 are not fully resectable, with even higher rates when involving the skull base)

• Modern results with resection and subsequent radiotherapy show control rates of 91-100% at 5 and 10 years with acceptably low complication rates (<6%)

Common Tumors• Pituitary Adenoma• Pituitary is the master gland regulating most of the body’s hormonal balance

secreting prolactin (Prl), growth hormone (GH), thyroid stimulating hormone (TSH) gonadotropic hormones (FSH/LH), and adrenocorticotropic hormone (ACTH), oxytocin and ADH

– 10-15% of intracranial neoplasms– 3rd most common after glioma and meningiomas– Many are asymptomatic, review of autopsy and radiographic studies reveal 16%

with pituitary lesions– Increases with age– Classically divided into two groups, functional or non-functional– Prolactin>Null cell>GH>ACTH

• Presentation– Endocrinologic disturbance, usually prolactin with amenorrhea/galactorrhea/sexual

dysfunction or GH and acromegalic features (increasing hand/foot size, coarse facial features, frontal bossing, prognathism, macroglossia)

– Mass effect-Primarily visual loss– Pituitary apoplexy – Headache, visual loss, CN palsy, hypotension– Hypopituitarism 75% hypogonadal, 36% hypoadrenal, 18% hypothyroid

Common Tumors

• Pituitary Adenoma– Management

• Prolactinoma-Dopamine agonists (Bromocriptine, Dostinex), surgery for failure

• GH, ACTH, Non-functioning-Surgery

• Surgery performed via transphenoidal approach

• Radiotherapy for residual tumor in certain circumstances (long term chance of hypopituitarism approaches 40%), appropriate approach may be observation until recurrence

Common Tumors

• Pituitary Adenoma

Brain metastases• According to 2008 American Cancer Society Registry,

1.4 million Americans diagnosed with cancer every year

• Average survival 3-6 mo with radiation alone• Extended survival to approx 12 mo with surgery and

radiation treatment• 40% or >500,000 will develop brain metastases• 1/3 of these patients are surgical resection candidates

Brain metastases

• General conditions:– <3 cm asymptomatic with known

primary cancer with imaging characteristics consistent with mets then Gamma knife, conformal radation (IMRT)or WBRT plus gamma knife boost can be used

Brain metastases

• Surgery should be considered first line for:– Any lesion greater than 3 cm– Any symptomatic lesion regardless of size– Any lesion near eloquent regions (motor

cortex, visual regions, speech, or optic nerves)– Questionable primary cancer diagnosis

• Very remote history of cancer• Pathology not known to metastasize to brain

– Failure of radiation therapy– Persisting corticosteroid requirement– Palliative for mass effect and symptom relief

Evidence?

• Level 1Evidence– Surgical resection plus WBRT versus

surgical alone• Good performance status (functionally

independent, less than 50% of time in bed), KPS >70

• Limited extra-cranial disease• Insufficient evidence to make a recommendation

for patients with poor performance scores, advanced systemic dz, or multiple brain mets

Evidence

Not everyone fits the guidelines – patient

example

• 68 yo female h/o breast Ca. Systemic disease controlled. Poor performance status due to hemiparesis

• 2.9 cm mass in eloquent region – thalamus, superior brainstem

• Very difficult surgical access with high potential for complication if not performed with precision

Pre-op

Post-op

Patient Example• Post operative weakness requiring rehab for 2 weeks• Improved and discharged home. At 1 month, fully independent with

minor left hand dexterity complaints, 4+/5 strength• Stereotactic conformal fractionated (5 fx) treatment to resection

cavity only• Alive with KPS 90 8 months post-op. No systemic disease

progression• Would fractionated treatment alone have provided same benefit? • If she had WBRT, would she have started developing the late

cognitive deficits (>12% at 1 year) given her likely long-term survival?

• Were we “lucky” at surgery?

Summary• Don’t believe every low survival statistic, data is based on

only Level 1 evidence from 1 single RCT completed in 1998, over ten years ago and not powered to detect OS as an endpoint

• WBRT is toxic over long term and should be avoided if other methods can be used, thus concurrent evaluation by radiation oncology AND neurosurgical oncology warranted

• Survival is dictated by systemic disease status, patients only die from CNS progression in 1/10 cases. Thus, certain pathology (breast) warrant a more aggressive surgical and focal radiation strategy

• Given low complication rate from craniotomy, palliation of symptoms and prolonged maintenance of QOL via surgical resection for large masses must always be considered, even those with advanced systemic disease

Radiosurgery/Radiotherapy

• Gamma Knife radiosurgery• Whole brain radiotherapy• Fractionated conformal radiotherapy

Diagnosis-Signs and Symptoms

• Variability depending on tumor type, and thus typical location, growth pattern, seizure propensity, etc.

• Most common presentation is progressive neurologic deficit, 68% and motor weakness, 45%, headache in 54%, seizures in 26%

• Supratentorial– Increased ICP

• Mass effect of tumor and/or edema• Blockage of CSF drainage (hydrocephalus)

– Progressive focal deficit including weakness and aphasias• Destruction of brain tissue• Compression of brain tissue by mass/edema/or hemorrhage• Compression of cranial nerves

– Headaches• With or without increased ICP• Classic: Worse in the morning• Worse with cough, straining, bending forward• Associate with nausea/emesis• Only 8% present with “Classic” brain tumor headache• Variable presentations• Etiology

– Increased ICP– Invasion of dura, blood vessels, periosteum– Secondary to difficulty with vision from CN dysfunction (3,4,6)– Hypertension with or without presence of Cushing’s Triad– Psychogenic

Diagnosis-Signs and Symptoms

• Supratentorial– Seizures: Evaluation for tumor should be initiated for patient >20 years old, if imaging negative,

should be repeated at later date• Rare with posterior fossa (cerebellum) and pituitary tumors

– TIA/CVA mimicry• Vessel thrombosis by tumor cells• Intracerebral hemorrhage – hemorrhages in certain age groups without hypertension or those with

hypertension but in atypical locations often have MRI evaluation– Pituitary

• Endocrine• Apoplexy• CSF leak

• Infratentorial– Most p-fossa present with signs and symptoms of increased intracranial pressure (ICP) due to

hydrocephalus (HCP)• Headache• Nausea/vomiting due to HCP, or pressure on vagal nucleus or area postrema• Papilledema• Gait disturbance/ataxia• Vertigo• Diplopia• Cerebellar hemisphere causes ataxia of extremities, vermis causes truncal ataxia, broad based gait• Brainstem involvement causes multiple cranial nerve deficits, nystagmus, and long tract abnormalities

Diagnosis- Signs and Symptoms

Diagnosis-Signs and Symptoms

Diagnosis-Signs and Symptoms

Diagnosis-Signs and Symptoms

Diagnosis-Signs and Symptoms

• As a summary:• Stroke-like symptoms OR• Change in level of consciousness – may indicate ICP

elevation or recent seizure and post-ictal state• Pervasive deficit• Evolving deficit• Anyone with history of cancer, remote or recent,

heavy smoker

Diagnosis-Neuroimaging/ CT vs MRI

• MRI provides much better delineation of tissues/tumor in multiple planes

– Contrast is necessary (in those with metastatic disease, double dose (>30 ml) or triple dose contrast provides much greater sensitivity

– Certain characteristics may lead one to think of one type of tumor versus another, or to differentiate from non-tumor etiologies (MS, encephalitis, abscess, stroke, etc)

• CT is much better for calcification (10x more sensitive), somewhat easier to date hemorrhage due to the complex signal characteristics on MRI which change day by day

Diagnosis-Neuroimaging

• MRI will not diagnose a tumor beyond a doubt in most circumstances, one must obtain tissue for pathological analysis

Diagnosis-Neuroimaging

• Metabolic Imaging– PET (positron emission

tomography) evaluates the metabolic activity (primarily glucose) of the brain, tumor, and other pathology

– 11C Methionine PET (MET PET) theoretically indicates the incorporation of this amino acid into metabolic pathways

– Ultimately, the goal is to differentiate from other non-tumor etiologies, and secondly to resolve the histologic grade of a tumor

– Not routinely used, nor is it standard of care

Diagnosis-Neuroimaging

MRS

57 yo female

Diagnosis-Neuroimaging

• Functional Imaging– Functional MRI

(fMRI) utilizes differences in blood flow and oxygen metabolism during activation of the cortex during specific tasks to elucidate eloquent regions of brain necessary for that function

– Most specific for motor and sensory, less so for language

– Comparable to PET scanning, but higher resolution, greater availability and shorter examination time

Diagnosis-Neuroimaging

• Diffusion Tensor Imaging (DTI)– Previous methods illustrate cortical localization, but do not

illustrate subcortical function, thus besides intraoperative stimulation, tumor delineation from functional tissue may be quite difficult when resection proceeds deeper into the brain

– A technique used to illustrate subcortical white matter tracts– Used to delineate the neurons necessary for motor function

from the cortex through the brainstem– Can be performed with intraoperative MRI where real-time

imaging can be performed showing the proximity of resection to critical areas

Diagnosis-Neuroimaging

• Merging of all modalities to illustrate areas which are necessary to preserve during surgical resection or contrary, areas which are severely damaged where resection can be performed with large margins with “safe disregard”

Surgery-Craniotomy and Image Guidance

• Stealth Navigation• Intraoperative MRI• Intraoperative CT

Surgery-Craniotomy and Image Guidance

Surgery-Craniotomy

Image Guided Neurosurgery

Innovation

How safe is it really?• Overall morbidity and mortality rate

for craniotomy for brain tumor is 25-35%. This accounts for all levels of severity

– Complication rates are extremely patient population dependent

– There are grey areas: what is considered a complication?

• Complications– Neurological

• Direct injury to normal brain structures• Brain edema

– Minimized use of retractors– Patient postioning– Use of mannitol/corticosteroids– Subtotal vs total resection

• Vascular injury (1-2%)– Arterial - immediate– Venous secondary to retraction – may be

delayed• Hematoma (1-5%)

– Early postoperative period with altered LOC

– Focal neurologic deficit (FND)– Seizures– Secondary to

» Intraparenchymal hemorrhage within resection bed

» Subdural/Epidural hematoma

Complications• Regional (3-5%)

– Associated with the surgical site• Infection (1%)

– Associated with proximity to paranasal sinuses– Active CSF fistula– Foreign body– Long surgery– Intensive corticosteroid use– Preoperative antibiotic should be active against

skin flora (S. Aureus/Epi and Propionibacterium acnes) but need not cross blood brain barrier. Post op antibiotics not usually necessary unless prolonged case

• CSF leak– Increased risk in the elderly– Those in poor neurological state at baseline– Posterior fossa

• Increased risk with reoperation• Possible increased risk in those that have

undergone radiation treatment• Seizures (0.5-5%)

– Preoperative epilepsy– Tumor proximity to motor cortex– Degree of cortical injury– Prolonged retraction (transcortical approach to

deep seated tumor)– Meta-analysis of 12 studies failed to demonstrate

efficacy of prophylactic anticonvulsant– Anticonvulsant prophylaxis only or those who

have already experienced seizure

Complications• Systemic (5-10%)

– Elderly (>60)– Neurologically impared (KPS<60 = requiring occasional assistance

or more)– Most frequent complication is DVT

• 1st month 1-10% after craniotomy• 12 months 20%• Patients with GBM or systemic cancer at highest risk but also those with

– Age>60– Lower extremity paresis– Prolonged bed rest– Long surgery

• Mobilization early after surgery• SCD/TEDs equal in effectiveness

– Compression boots increase fibrinolytic activity and are favored• LMWH reduces thromboembolic events without affecting frequency of

intracranial hemorrhage. May be instituted 24 hours post-op as long as imaging reveals no postoperative hemorrhage

• Mortality after craniotomy– Has decreased over the past 3 decades, currently range between

1.7 and 2.7%– Most deaths result from neurological complications such as

hematoma, edema and subsequent herniation, or tumor progression

– Systemic complications are evenly distributed among PE, MI, and sepsis

– Regional complications usually resolve with medical or surgical intervention and do not progress to death

Complications • Higher volume centers experience much less complication• INI represents one of the top 3 volumes in the Illinois/Iowa

region with over 200 operative tumors and 250 gamma knife cases annually– 0% infection– 0% CSF leak– 0.3% mortality within 30 days– 10% post-operative onset seizure– 2% symptomatic stroke rate

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