Wednesday, March 25, 2009

The Problem of Broken Bones During the Handling

. Wednesday, March 25, 2009 .

ABSTRACT The major welfare concern during the
handling of laying hens is that of broken bones. With
particular reference to the United Kingdom, this paper
reviews the work that has been done to quantify the
problem, to examine the causes, and to investigate
factors that affect it. The number of freshly broken bones
found in live birds prior to slaughter and the number of
old healed breaks found at slaughter are unacceptablyhigh. End-of-lay hens from battery cages have especially
fragile bones and these are easily broken during the
rough handling that is received during depopulation.
Birds from more extensive laying systems have stronger

bones and suffer fewer breaks during depopulation but
have a greater prevalence of old healed breaks. The old
breaks occur as a result of collisions due to poor design
within these housing systems. The number of fresh
breaks can be reduced by increasing bone strength and
handling birds with more care. The numbers of old
breaks can be reduced by better design of housing
systems and the physical environment within them.

This paper reviews the main welfare problem that
occurs during the handling of hens within the United
Kingdom—that of broken bones. The handling and
transport of hens has been reviewed by Swarbrick
(1986), Broom and Knowles (1989), and Knowles and
Broom (1990a). This review focuses on the work that has
been carried out since the publication of these articles.
The most recent figures from the Ministry of
Agriculture, Fisheries and Food are for 1993, and these
put the total number of laying hens producing table
eggs within the UK at approximately 33 million birds.
As one laying cycle is approximately 52 wk and most
birds are slaughtered after the first production cycle, this
means that at present (1995) approximately 31.7 million
hens are transported for slaughter each year. However,
there has been a trend for the total number of laying
hens to decrease by approximately 800 thousand birds
per year since 1983, so if this trend continues, the figure
for 1997 will be closer to 30 million birds transported to
slaughter. More than 90% of these birds are kept in
battery cages.
The first survey describing the prevalence of broken
bones in caged hens within the UK found that 29% of
live birds had broken bones by the time they had
reached the water bath stunner, with on average 0.5
broken bones per bird (Gregory and Wilkins, 1989). The
main bones that had been broken were the ischium, keel,
humerus, and pubis, and these accounted for 70% of the
breaks. The authors identified removal from battery
cages and hanging on the slaughter line as the major
causes of the damage. A similar survey with broilers
found that 3% of the live birds had received broken
bones before they had reached the water bath stunner
(Gregory and Wilkins, 1990). As 600 million broilers are
slaughtered annually, this means that approximately 18
million live broilers and 9.5 million hens receive breaks
each year. From the point of view of welfare, such large
numbers of animals with broken bones is entirely
unacceptable. Broom (1986) defines welfare as the state
of an individual as regards its attempts to cope with its
environment. Most people would agree that such
extreme physical damage is indicative of an inability to
cope and shows very poor welfare. The pain associated
with such damage is likely to be great. Although the
numbers of broilers with broken bones is greater, it is
likely that the situation with hens could be improved
more easily as a much greater proportion of hens suffer
from breaks.
Received for publication August 12, 1995.
Accepted for publication December 15, 1997.
1To whom correspondence should be addressed: toby.knowles@
It is important to describe how the prevalence of
breaks is estimated, as differing methods will result in a
range of values for the same population. Methods used
have included palpation of the whole carcass, or specific
parts, after it has been hung on the line, the use of meat
TABLE 1. List of the bones examined in the
surveys of Gregory and Wilkins
Femur Scapula
Tibia Coracoid
Fibula Furculum
Humerus Radius
Ribs Ischium
Ulna Ilium
Sternum Pubis
inspectors’ records, and physical dissection of the
carcass with the examination of specific bones. All but
the latter method tend to underestimate the number of
broken bones (Gregory and Wilkins, 1992). All recent
surveys within the UK have been carried out by
Gregory and Wilkins and employed the latter method,
in which birds were first killed in a convulsion-free
manner in order to avoid further breaks. During
dissection, only the bones identified in Table 1 were
examined for fractures, as a full dissection of each
carcass was considered to be too time-consuming for the
number of birds required for the surveys: it has been
estimated that sample sizes of at least 100 birds within a
flock are needed to give an accurate assessment of the
prevalence of breaks (Gregory and Wilkins, 1992).
In the first survey by Gregory and Wilkins (1989), it
was found that 29% of live hens from cages have freshly
broken bones, but also that 5% of caged birds had old
breaks that had healed (Gregory et al., 1990). The most
probable cause of the old breaks was poor handling
during rearing and placement. The range of fresh breaks
in different flocks can be very large, from 0 to 50%
(Gregory and Wilkins, 1989), making it difficult to
accurately determine an overall figure for the UK. But
the wide range in incidence between flocks does indicate
that there must be particular husbandry and handling
practices that lead to broken bones. A better understanding
of these could lead to an improvement in the
Following publication of the initial figures in 1989, a
joint industry-welfare guide to the handling of spent
hens was produced by the British Poultry Federation
and the National Farmers’ Union. These general guidelines
emphasized the need for preparation and planning,
ensuring that sufficient staff were available and that
they were all aware of the need for careful handling. The
recommendations also included the use of low light
levels, catching the birds by two legs instead of by just
one, and the use of a slide at the entrance of the cage to
prevent birds being knocked against the feeding trough.
More recent surveys have found 14% of caged birds
with fresh breaks but up to 13% with old breaks
(Gregory et al., 1994). This finding may mean that the
situation with respect to new breaks has improved but
an accurate overall determination is difficult.
It has been known for many years that modern laying
hens can have unusually weak bones (Rowland et al.,
1968; Rowland and Harms, 1970). Previous authors, such
as Riddle (1981), considered osteoporosis to be the sole
cause of bone weakness. In osteoporosis, the bone is
normally mineralized but its total mass is reduced, often
with slender trabeculae and large spaces within the
bone. However, Randall and Duff (1988) reported an
increase in the incidence of bone disease in which flocks
showed a variable response to dietary treatments. They
proposed that the osteopenia (bone loss) they found
could be due to a combination of osteoporosis and
osteomalacia. In osteomalacia, the bone is present but
incompletely mineralized. Birds suffering from osteopenia
due to osteomalacia, or osteoporosis exacerbated by
osteomalacia, respond to dietary treatment, whereas
birds suffering from osteoporosis alone do not respond
to dietary treatment. Generally, bone fragility in end-oflay
hens on a properly balanced diet is due to
osteoporosis, because in modern, high production hens
structural bone is mobilized throughout the laying
period in order to contribute to the formation of
eggshell. However, there are other factors that can affect
the problem.
Lanyon et al. (1986) have shown in laying hen turkeys
that for bone to maintain its normal thickness and
functional structure it must be subject to some level of
dynamic loading or osteoporosis results. They also
demonstrated that the effects of disuse (lack of loading)
and bone loss due to calcium deficiency were additive,
but that bone loading provided a substantial conservative
influence on bone mass even under conditions of
calcium deficiency, in which there was extensive mineral
resorption. Thus, where a bird’s movements are restricted
and it is unable to provide normal dynamic
loading, the effects of the restriction and any dietary
insufficiencies will be additive, but when a bird is free to
move and provide normal loading, the effects of dietary
insufficiencies will be reduced.
Osteomalacia and osteoporosis both cause a weakening
of the bone. Knowles et al. (1993) have shown that
birds with weaker bones are more likely to sustain
broken bones, and that even the differences in bone
strength found within a population of birds kept in the
same type of cage and on the same diet are enough to
influence the likelihood of a bird sustaining a break.
Husbandry System
Different husbandry systems allow various degrees of
freedom of movement, and the more restrictive systems
lead to weaker bones and thus to an increased likelihood
of a break during handling (Knowles et al., 1993). Studies
relating freedom of movement and bone strength within
different systems have been carried out by Knowles and
Broom (1990b), Nørgaard-Nielson (1990), Gregory et al.
(1991), Fleming et al. (1994), and van Niekerk and
Reuvekamp (1994). Generally, battery cages allow the
least amount of movement and produce birds with the
weakest bones whereas percheries allow the most movement,
promote wing movement, and produce stronger
bones. In one survey, Gregory et al. (1990) found 24% of
birds from battery cages to have freshly broken bones,
prestun, compared with only 10% of birds from perchery
systems. The same paper reports another survey in which
31% of birds from cages had freshly broken bones
compared with 14% of birds from free range systems. As
well as producing weaker bones, there is a greater
likelihood in intensive systems that birds will come into
contact with solid objects during catching. This too would
tend to increase the prevalence of breaks.
The introduction of a perch into a battery cage systems,
and its increased use, have been shown to increase the
strength of the bones in the leg but the effect was only
minor and was thought unlikely to affect the prevalence of
breaks (Hughes and Appleby, 1989; Hughes et al., 1993;
Wilson et al., 1993).
The presence of an old healed break at slaughter could
be thought of as indicative of poorer welfare than a break
that has occurred a few hours prior to slaughter. An old
break will have been felt over a prolonged period of time.
Those found have often mended very poorly, perhaps
resulting in a lifetime of pain. The prevalence of old breaks
has been shown to vary considerably with different types
of housing system. Although the prevalence of new
breaks is lower in perchery and free range systems than in
battery systems, old breaks tend to be more prevalent in
the more extensive systems. Gregory et al. (1990) give
figures of 5, 12, and 25% of birds with healed broken
bones, from battery, free range, and perchery systems,
respectively. Gregory and Wilkins (1991) attributed the
high prevalence of old breaks in the perchery units to
accidents during flight and landing. Within percheries,
the design and layout of the furniture are likely to be
important in determining the number of accidents, as
large differences in the prevalence of old breaks between
types of perchery have been observed (Gregory and
Wilkins, 1992). In order to put the figures for old breaks
into perspective, Gregory and Wilkins (1991) carried out a
survey of captured pigeons. Three per cent of pigeons
thought to have been racing pigeons had old healed
breaks, whereas 6% of feral pigeons were found to have
old breaks. However, a direct comparison cannot be made
because hens, as heavier birds, would be more likely to
sustain a break than pigeons during an accident of similar
severity. Additionally, the number of wild birds with old
breaks will be reduced through selective predation and an
inability to feed.
Light Intensity
The effect of light intensity during lay in battery hens
was investigated by Gregory et al. (1993a). They found that
birds kept at 15 lx had more old, healed breaks than birds
kept at 2 or 0.5 lx. In a trial looking at lighting patterns,
Gregory et al. (1993b) found no effect on the breaking
strength of the tibia or humerus at the end of lay with an
intermittent pattern [3 h light:3 h dark (´4)] compared
with conventional regimens (15 h light:9 h dark) or (17 h
light:7 h dark).
Rearing Method
Anderson and Adams (1994) found no difference
between the tibia breaking strengths of 68-wk-old hens
reared in cages or reared on litter, but Gregory et al. (1991)
found a greater number of broken bones in hens that had
been reared on litter. Most of the difference was due to a
greater damage to the humerus in the litter birds, which
also had weaker humeri. No consistent difference in tibia
breaking strength between the treatments was found.
When birds are caught they predispose themselves to
injury if they make violent attempts at escape. Reed et al.
(1993) reported that enriching the environment of caged
hens with plastic balls and bottles and exposing them to
daily human handling reduces their fear reactions during
catching and that this resulted in fewer potentially
injurious contacts with the cage. They later reported that
hens with lower fear reaction scores tended to sustain less
bruising and fewer breaks (Reed et al., 1994).
Age at Sexual Maturity,
Age at Culling, and Molting
Gregory et al. (1991) retarded sexual maturity to 157 d
in one group of caged layers and at 82 wk of age compared
the prevalence of broken bones with a control group that
had achieved sexual maturity at 147 d. The two groups
were not measurably different, with 19 and 18% of birds,
respectively, suffering broken bones. However, further
studies revealed a positive correlation between age at
sexual maturity and the breaking strength of the tibia and
humerus and also a negative correlation between age at
sexual maturity and the prevalence of freshly broken
bones (Gregory and Wilkins, 1992), although the differences
found in breaking strength were not great. In a small
study involving three groups of approximately 120 hens
slaughtered at 57, 67, and 77 wk, Gregory et al. (1991)
found no change in the prevalence of broken bones with
increasing age. Gregory et al. (1991) found that forced
moulting at 50 wk of age had little effect on bone strength
over the moulting period, but bone strength increased by
7% in the humerus and 17% in the tibia from the end of
molt to the end of lay at 86 wk.
Breed and Strain
Large strain differences in bone strength were found by
Rowland et al. (1972) in the U.S. In the UK, differences in
tibia strength between breeds were found by Knowles et
al. (1993) but the differences were small and were not
measurably associated with the prevalence of new breaks.
Gregory et al. (1991) found no difference in the prevalence
TABLE 2. The diets used in the study by Whitehead (1994)
1. Control – wheat/fish/soybean meal (CP, 170 g/kg; ether
extract, 20 g/kg; Ca, 35 g/kg; P, 6 g/kg)
2. Control diet plus added maize oil at 50 g/kg
3. Control diet with limestone flour replaced by oystershell
4. Control diet with sodium fluoride supplement (200 mg/
5. Control diet with vitamin C supplement (250 mg/kg)
6. Control diet with 1,25-dihydroxyvitamin D supplement
7. Diet with less CP (150 g/kg) with vitamin K supplement
(20 mg/kg)
8. Diet with less P (4.5 g/kg)
of new breaks among different breeds within the UK.
However, in later work, they included a white breed that
was found to have a stronger tibia but weaker humerus
(Gregory and Wilkins, 1992). White breeds have also been
found to have a greater prevalence of breaks (Gregory et
al., 1994). It is likely that the modern breeds of brown bird
that are now used almost exclusively within the UK have
become more homogenous with continued selection for
Catching Method
It has been shown that the way in which the birds are
handled at catching can have a great effect on the number
of bones that are broken. A researcher working with a
team of professional “pickers” caused fresh breaks in only
14%of the birds that he caught and carried out of a battery
system compared with an average of 24% for the other
“pickers” (Gregory and Wilkins, 1989). The effect that the
method of removal from the cage has on the prevalence of
broken bones has been evaluated in a series of trials
(Alvey et al., 1991; Gregory et al., 1992, 1993a). In general,
pulling birds from the cage by one leg produces more
breaks than pulling birds from the cage by two legs.
Pulling birds out in a group, rather than singly, also tends
to produce more breaks. However, these differences did
not exist in all trials, suggesting that the effect was specific
to particular combinations of flock and picker. Most of the
differences found between treatments were attributable to
a greater number of broken femurs. It was thought that
one cause of broken bones was contact with the sides of
the feed trough as birds were withdrawn from the cage.
However, the inclusion of a slide over the trough did not
affect the number of breaks in any of the trials. Knowles
and Broom (1993) investigated the corticosterone
response of hens to different catching methods. Generally,
levels of plasma corticosterone rise during a traumatic
event. Although not significant, there was some indication
that catching birds individually by both legs produced the
smallest increase in plasma corticosterone levels. Carrying
the inverted birds out of the house by hand, as is normal
commercial practice, produced a greater corticosterone
response than crating birds directly from the cage and
then carrying them from the house in the crate, but there
was no difference in the numbers of broken bones
between the two treatments.
The effect of light intensity during catching was
investigated by Gregory et al. (1993a). Reducing light
levels to 2 lx during catching for birds normally housed at
15 lx improved handling. Increasing light levels to 12 lx for
birds normally housed at 2 lx had no effect on ease of
A number of trials have been carried out to investigate
the possibility of remedying bone fragility due to
osteoporosis by dietary means. Whitehead (1994) fed eight
different diets throughout the laying year (Table 2). He
found that none of the diets prevented osteoporosis and
that a high fat diet, with added maize oil, actually
accelerated bone loss. Medullary bone content was
increased by fluoride or ground oyster shell. He concluded
that osteoporosis could not be prevented by
dietary means but that a good diet was necessary for
minimizing its severity.
Orban et al. (1993) studied the effect of feeding different
levels of dietary ascorbic acid (from 0 to 3,000 ppm) for 4
wk on the mineral content, density, and breaking strength
of the femur, tibia, and metatarsus of laying hens. They
found no consistent difference in any of these measurements
between treatments. Koelkebeck et al. (1993) found
some evidence that carbonated water increased the tibia
breaking strength of older laying hens exposed to a shortterm
heat stress.
The problem of bone breakage during the handling of
end-of-lay hens, particularly those confined in battery
cages, continues to be a major welfare issue. The amount
of trauma incurred by birds at depopulation can be
reduced by two means. Firstly, an improvement in bone
strength might enable the birds to better withstand the
insults inflicted during depopulation. However, with
caged birds, only small, inconsistent improvements have
been demonstrated by modifications to husbandry
practices such as lighting, cage design, and rearing
method. The second and more direct method is to
reduce the number of insults incurred. Careful catching
has been shown to greatly reduce the number of bones
broken. The ease with which birds can be removed from
different designs of cage is also likely to have some
effect. The number of birds having breaks that occurred
both before and during lay and that have subsequently
healed is also a major welfare issue. But this condition is
most prevalent in the more extensive husbandry systems,
which allow more freedom of movement and
promote bone strength, and also produce the least
number of broken bones at depopulation. The indications
are that a better knowledge of how these injuries
occur could lead to better design and placement of the
furniture and fittings within these systems and a
reduction in the number of old breaks found at
An important point to be emphasized is that any
measures intended to reduce the numbers of either old
or new breaks can only be validated by subjecting a
large number of individual carcasses to a full dissection,
a costly and time-consuming process.
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brain cancer


There are two types of brain tumors: primary brain tumors that originate in the brain and metastatic (secondary) brain tumors that originate from cancer cells that have migrated from other parts of the body.
Primary brain cancer rarely spreads beyond the central nervous system, and death results from uncontrolled tumor growth within the limited space of the skull. Metastatic brain cancer indicates advanced disease and has a poor prognosis.
Primary brain tumors can be cancerous or noncancerous. Both types take up space in the brain and may cause serious symptoms (e.g., vision or hearing loss) and complications (e.g., stroke).
All cancerous brain tumors are life threatening (malignant) because they have an aggressive and invasive nature. A noncancerous primary brain tumor is life threatening when it compromises vital structures (e.g., an artery).

Incidence and Prevalence
In the United States, the annual incidence of brain cancer generally is 15–20 cases per 100,000 people. Brain cancer is the leading cause of cancer-related death in patients younger than age 35.
Primary brain tumors account for 50% of intracranial tumors and secondary brain cancer accounts for the remaining cases. Approximately 17,000 people in the United States are diagnosed with primary cancer each year and nearly 13,000 die of the disease. The annual incidence of primary brain cancer in children is about 3 per 100,000.
Secondary brain cancer occurs in 20–30% of patients with metastatic disease and incidence increases with age. In the United States, about 100,000 cases of secondary brain cancer are diagnosed each year.

Types of Brain Cancer
The World Health Organization (WHO) has nine categories of primary brain tumors, which are based on the types of cells in which the tumors originate. Gliomas are primary brain tumors that are made up of glial cells—cells that provide important structural support for the nerve cells in the brain.
Infiltrative astrocytoma and glioblastoma multiforme (GBM) account for nearly 85% of all brain tumors, with the remainder spread among the other seven types.
Tumor Type Cell Origin
Infiltrative astrocytoma Astrocytes
Pilocytic astrocytoma Astrocytes
Oligodendroglioma Oligodendrocytes
Mixed oligoastrocytoma Oligodendocytes and astrocytes
Glioblastoma multiforme (GBM) Astrocytes and other brain cell types (astroblasts, spongioblasts)
Ependymoma Ependymocytes
Medulloblastoma Primitive neural cell
Meningioma Meninges
Tumor grade: All gliomas, except GBM, range from well-differentiated tumors (low grade) to anaplastic, that is, completely chaotic, undifferentiated (high grade). High-grade tumors are more aggressive and are associated with lower survival rates. In terms of surviving the disease, the grade of the tumor is the most important feature.
Primary Tumors
A primary brain tumor usually develops through a complex series of molecular and cellular mutations and may take years to acquire enough mass to cause symptoms that bring the disease to a person's and/or a physician's attention.
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* astrocytoma–most common type of brain tumor in children; originates in the brainstem, cerebellum, white matter of the cerebrum, or spinal cord
* brainstem glioma–originates in the medulla, pons, or midbrain
* choroid plexus papilloma–originates in the ventricles
* ependymoma–originates in the membrane that lines the bentricles and central canal of the spine
* glioblastoma multiforme–most common types in adults; originates in glial cells in the berebrum
* medulloblastoma–second most common type in children; originates in the fourth cerebral ventricle and the cerebellum; often invades the meninges
Other types of primary brain cancer include the following:
* acoustic neuroma–originates in the vestibulocochlear nerve
* lymphoma–originates in lymphocytes; common in HIV/AIDS patients
* meningioma–originates in the meninges
* pineal gland tumor–rare; originates in the pineal gland
* pituitary adenoma–originates in surface cells of the pituitary gland
* schwannoma–originates in cells of the myelin sheath that covers neurons
Secondary (Metastatic) Brain Tumors
In adults, the most common types of cancer that spread to the brain are the following:
* melanoma
* breast cancer
* renal cell carcinoma
* colorectal cancer
The prognosis for people who develop brain metastases is generally poor.
Causes and Risk Factors
Aside from a known association with exposure to vinyl chloride, there are no known chemical or environmental agents that lead to the development of brain tumors.
Genetic mutations and deletions of tumor suppressor genes (i.e., genes that suppress the development of malignant cells) increase the risk for some types of brain cancer. Inherited diseases that are associated with brain tumors include the following:
* Multiple endocrine neoplasia type 1 (pituitary adenoma)
* Neurofibromatosis type 2 (brain and spinal cord tumors)
* Retinoblastoma (malignant retinal glioma)
* Tuberous sclerosis (primary brain tumors)
* Von Hippel-Lindau disease (retinal tumor, CNS tumors)
Patients with a history of melanoma, lung, breast, colon, or kidney cancer are at risk for secondary brain cancer.
Exposure to vinyl chloride is an environmental risk factor for brain cancer. Vinyl chloride is a carcinogen, that is, a cancer-causing substance. It is used in manufacturing plastic products such as pipes, wire coatings, furniture, car parts, and housewares, and is present in tobacco smoke.
Manufacturing and chemical plants may release vinyl chloride into the air or water, and it may leak into the environment as a result of improper disposal. People who work in these plants or live in close proximity to them have an increased risk for brain cancer.
Signs and Symptoms
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A brain tumor can obstruct the flow of cerebrospinal fluid (CSF), which results in the accumulation of CSF (hydrocephalus) and increased intracranial pressure (IICP).Nausea, vomiting, and headaches are common symptoms.
Brain tumors can damage vital neurological pathways and invade and compress brain tissue. Symptoms usually develop over time and their characteristics depend on the location and size of the tumor. A brain tumor in the frontal lobe may cause the following:
* Behavioral and emotional changes
* Impaired judgment
* Impaired sense of smell
* Memory loss
* Paralysis on one side of the body (hemiplegia)
* Reduced mental capacity (cognitive function)
* Vision loss and inflammation of the optic nerve (papilledema)
A tumor located in both the right and left hemispheres of the frontal lobe often cause behavioral changes, cognitive changes, and a clumsy, uncoordinated gait.
A tumor in the parietal lobe may cause the following symptoms:
* Impaired speech
* Inability to write
* Lack of recognition
* Seizures
* Spatial disorders
Vision loss in one or both eyes and seizures may result from a tumor located in the occipital lobe.
Tumors that develop in the temporal lobe are often asymptomatic (i.e., without symptoms), but some may cause impaired speech and seizures.
A tumor in the brainstem may produce the following symptoms:
* Behavioral and emotional changes (e.g., irritability)
* Difficulty speaking and swallowing
* Drowsiness
* Headache, especially in the morning
* Hearing loss
* Muscle weakness on one side of the face (e.g., head tilt, crooked smile)
* Muscle weakness on one side of the body (i.e., hemiparesis)
* Uncoordinated gait
* Vision loss, drooping eyelid (i.e., ptosis) or crossed eyes (i.e., strabismus)
* Vomiting
Ependymoma originates in the lining of the ventricles and the spinal canal and may damage cranial nerves. When this happens, hydrocephalus, stiff neck, head tilt, and weakness may result.
Symptoms produced by a tumor of the meninges (meningioma) depend on which area of the brain is being compressed. They include:
* Headache
* Hearing loss
* Impaired speech (i.e., dysphasia)
* Incontinence
* Mental and emotional changes (e.g., indifference, disinhibition)
* Prolonged drowsiness (somnolence)
* Seizures
* Vision loss
A tumor located in the pituitary gland (i.e., pituitary adenoma) may increase the secretion of hormones and cause discontinuation of menstruation (i.e., amenorrhea) and excess secretion of milk (i.e., galactorrhea) in women. Impotence may occur in men.
Brain Cancer Diagnosis
The first step in diagnosing brain cancer involves evaluating symptoms and taking a medical history. If there is any indication that there may be a brain tumor, various tests are done to confirm the diagnosis, including a complete neurological examination, imaging tests, and biopsy.
Imaging Tests
Magnetic resonance imaging (MRI scan) is the diagnostic test of choice for brain cancer. ELectromagnetic energy produces detailed computer images of the brain from different angles. It can detect edema (swelling of brain tissue) and hemorrhage (bleeding). In some cases, a dye is injected intravenously to improve the contrast between an abnormal mass and normal tissue.
Computed axial tomography (CAT or CT scan) involves the use of x-rays and a computer to obtain images of the brain. A dye is often injected intravenously to improve the contrast between an abnormal mass and normal tissue. Not only can the tumor be seen, but the type of tumor sometimes can be identified with a CT scan.
Positron emission tomography (PET scan) helps the physician evaluate brain function and cell growth by producing images of physical and chemical changes in the brain. An injected radiopharmaceutical substance is absorbed by tumor cells in the brain. Measurements of brain activity are determined by concentrations of the substance and then fed into a computer, which produces an images of the brain.
PET can precisely locate a tumor and detect metastatic and recurrent brain cancer at earlier stages than MRI or CT scan. This technique also can be used to evaluate the tumor's response to chemotherapy and radiation treatment.
Examination of tumor tissue is the only way to arrive at an exact diagnosis of the tumor. In a biopsy, a small part of tumor tissue is removed surgically and then sent to a lab, where a pathologist examines it.
The type of tumor is determined by the type or types of cells (called grading) seen under the microscope, and, if malignant, the stage–that is, the degree of invasiveness, the growth rate, and the cancer cells' similarity to normal cells–is also determined.
In stereotactic biopsy imaging tests are used to locate the tumor, a small hole is made in the skull, and a hollow needle is passed through to obtain a core of tumor tissue. Examination of the sample provides an accurate diagnosis in over 90% of cases.
Possible complications resulting from the procedure include blood clot, hemorrhage, and infection. The rate of complications is very low, about 3%.
Treatment for brain cancer depends on the age of the patient, the stage of the disease, the type and location of the tumor, and whether the cancer is a primary tumor or brain metastases. The treatment plan is developed by the oncology team and the patient.
Treatment involves any combination of surgery, radiation, and chemotherapy. Some tumors require several different surgical procedures, and some can be treated with radiation alone.
Surgery is the treatment of choice for accessible primary brain tumors, when the patient is in good health. The goal of surgery is to remove as much of the tumor as possible without damaging nearby normal brain tissue. The prognosis improves when more than 90% of a tumor can be removed.
Removal is often complicated by the nature of the tumor (e.g., invasive, highly vascularized) and by its location. Partial removal (debulking) of the tumor can improve quality of life by alleviating symptoms and sometimes improve the effectiveness of radiation therapy or chemotherapy.
Before surgery, some important tests are performed. Patients over the age of 40 usually undergo an electrocardiogram (ECG or EKG) and a chest x-ray. Other tests are used to detect the presence of uncontrolled hypertension, diabetes, active coronary ischemia, or the presence of circulating anticoagulant (substance that inhibits normal blood clotting) in the blood. If any of these conditions are present, it may not be advisable to undergo craniotomy.
Craniotomy is the treatment of choice and the goal is to remove as much of the tumor as possible. The procedure is performed under general anesthesia and involves opening the skull (cranium).
The neurosurgeon makes an incision into the scalp and several holes (called burr holes) are made in the skull. A bone saw is used to join the holes together to create a flap of bone.
The bone flap is then removed to expose the brain and remove as much of the tumor as possible. After the tumor has been partially or completely resected, the bone flap is replaced and secured using fine wire. Recovery from the procedure may take as long as 8 weeks.
Complications of craniotomy include bleeding (hemorrhage), swelling (edema), increased intracranial pressure (IICP), infection, and brain tissue damage.
In laser microsurgery, MRI is used to pinpoint the location of the tumor and a laser is used to destroy the tumor. This procedure may be used after craniotomy to remove remaining tumor tissue.
Brain-mapping is performed under local anesthesia and sedation. Electrodes stimulate nerves in the brain, measure responses, and allow communication with the patient. The surgeon removes as much of the tumor as possible without damaging vital areas of the brain, such as those that control motor function and speech.
In some cases, a chemotherapeutic agent called BCNU is used following surgery. In this treatment, the neurosurgeon places a wafer soaked with BCNU (Gliadel®, BiCNU®) into the surgical cavity after the tumor has been removed. By applying it directly to the diseased area of the brain, side effects are limited and the drug has a more beneficial effect.
Postoperative care includes drug therapy with corticosteroids, histamine inhibitors (block stomach acid), and antiepileptics. Corticosteroids (dexamethasone and Decadron®) help reduce swelling and can relieve various postoperative neurological effects.
An MRI scan, with and without contrast, is often obtained to determine the extent of residual disease following surgery. Sometimes, a plan for rehabilitation is needed.
Radiation Therapy
Radiation is used when the entire primary tumor cannot be surgically removed. Most malignant brain tumors are treated with external-beam radiation even if the entire primary tumor is surgically removed, because hidden tumor cells often remain in brain tissue.
The survival rate for patients with malignant tumors (e.g., anaplastic astrocytoma, glioblastoma multiforme) more than doubles with radiation therapy, and it can prolong life for patients with low-grade gliomas as well.
Radiation therapists use several different approaches to treat primary brain tumors, but external-beam radiation is the most common. Local radiation therapy techniques, including external focal, brachytherapy, and stereotactic radiosurgery, may be administered to selected patients.
There are various other radiation techniques, some of which are being used on an experimental basis. An assortment of technologies, as well as the use of medications and other compounds, can make tumor cells more sensitive to radiation.
External-beam radiation
External-beam radiation, the traditional form of radiation therapy, delivers radiation from outside the body. Therapy usually begins a couple of weeks after surgery and is typically repeated at regular intervals for several weeks.
Hyperfractionation is a modified form of external-beam radiation that involves applying less intense but more frequent doses of radiation. Some benign tumors are treated with external-beam radiation to prevent recurrence, even if the entire primary tumor has been surgically removed. They also may be treated with radiation at the time of recurrence.
Stereotactic radiosurgery
Stereotactic radiosurgery delivers radiation to the tumor in a single dose and does not involve surgery, as the term may imply. In this procedure, a head frame supporting a CT or MRI scanner may be attached to the skull. With the aid of computer imaging, the radiologist is able to pinpoint the exact location of the tumor and aim the beam of radiation directly at it.
Some tumors, however, cannot be treated with the intense local radiation of radiosurgery. For example, tumors near the optic nerves are better treated with several small doses, because the optic nerves are especially sensitive to radiation. These tumors may be treated using stereotactic radiotherapy. Stereotactic radiotherapy involves applying many small doses of radiation, using the same imaging techniques used in stereotactic radiosurgery.
Newer stereotactic techniques usually do not involve the use of the head frame. Radiation often is delivered from several different directions, hitting the tumor at various angles. The advantage of using localized radiation is that the surrounding, healthy tissue is left undestroyed. This treatment may be used in addition to external-beam radiation, especially in cases of malignant gliomas and mestastases that are in deep or sensitive areas of the brain. Types of machines that are used to perform stereotactic radiosurgery include the Gamma knife® and modified linear accelerators (LINAC; e.g., CyberKnife®).
The Gamma knife uses ioninzing beams of radiation (called gamma rays) that are sent from different angles and come together at a single point on the tumor. Each beam is low dosage; however, when they converge, the intensity and destructive power is high. This treatment is used to treat small tumors.
Linear accelerators (e.g., CyberKnife®) involve using small doses of radiation over multiple sessions (called fractionated stereotactic radiotherapy). In this treatment, which allows larger tumors to be treated, the patient is positioned on a bed that can be moved, providing flexible positioning. Linear accelerators produce positively-charged atoms (called protons) in patterns that are matched to the size and shape of the tumor and used to destroy cancer cells.
Brachytherapy involves implanting capsules containing radioactive substances into the tumor to deliver localized radiation. It is frequently applied to treat recurrent disease in an area previously treated by external-beam radiation.
Advantages of this type of radiation therapy include sparing vital structures close to the tumor and a shorter length of treatment (i.e., hours to days instead of weeks).
Radiation follow-up
Because loss of pituitary function can be a long-term side effect of radiation therapy, an endocrine evaluation is an important part of follow-up care for patients who have received radiation. Neuropsychological testing may also be done to evaluate whether a patient has incurred diminished intellectual activity resulting from brain tumor radiation.
Generally, tumors are satisfactorily treated with radiation and/or surgery. Chemotherapy is not used for benign tumors and is generally not a very effective treatment for most malignant primary brain tumors or metastatic tumors.
The problem with chemotherapy is that it works by interrupting mitosis, the process of cell division. Many brain tumors grow slowly by nature, so slowing their growth by chemotherapy doesn't do much good. Another problem with chemotherapy is that there are few chemical agents that can cross the blood-brain barrier and get to the tumor.
The capillaries and arteries in the central nervous system are unlike the vessel walls found in the rest of the body, which allow proteins and large organic molecules to pass out of the bloodstream and into tissues. Vessel walls in the CNS allow only water, small solutes, and simple gases such as oxygen and carbon dioxide to pass into brain tissue. While this protects the brain from exposure to chemical flux in the body, it also creates a barrier against many therapeutic agents, making chemotherapy problematic.
Chemotherapy uses chemicals that are designed to poison tumor cells, but it's difficult to know which chemicals will reach which tumors. So, a combination of chemicals is usually used to treat a brain tumor.
Some cancer cases require chemotherapy after surgery and radiation. Chemotherapy is also used as a radio-sensitizing agent with radiation to control a recurrent tumor and to treat patients who can no longer tolerate radiation therapy.
Overall, studies have shown that patients who receive chemotherapy for malignant tumors have improved survival rates compared to patients who do not. The effectiveness of chemotherapy depends on the tumor type (medulloblastomas, anaplastic astrocytomas, and glioblastomas respond in varying degrees).
Chemotherapy is often used in very young children to delay radiation therapy for as long as possible. Some meningiomas respond to antiprogesterone agents. Most mestastatic brain tumors do not respond to chemotherapy, although there are exceptions. For these, the best chemotherapy agent is usually the one that has been the most effective with the primary cancer.
Agents that commonly work in patients with high-grade gliomas include procarbazine, platinum analogs (cisplatin, carboplatin), the nitrosureas, and an oral medication called Temodar® (temozolomide). In March 2009, the U.S. Food and Drug Administration (FDA) approved an intravenous (IV) form of temozolomide.
One chemotherapeutic agent that has proved to be effective is BCNU. The neurosurgeon places a wafer soaked with BCNU (Gliadel®, BiCNU®) into the surgical cavity after the tumor has been removed. By applying it directly to the diseased area of the brain, side effects are limited and the drug has a more beneficial effect.
Chemotherapy agents being tested for use in recurrent glial tumors include Taxol® (paclitaxel), irinotecan, topotecan, and high-dose tamoxifen with either carboplatin or procarbazine. Other chemotherapeutic agents for the treatment of recurrent gliomas include interferon and retinoic acid.
There are many experimental treatments, ranging from novel chemotherapeutic agents to drug therapy to new ways of applying radiation, that your neurologist, neurosurgeon, radiation oncologist or neuro-oncologist can discuss with you. As with any serious illness, it is generally a good idea to understand your options, get a second or third opinion, and gather as much information as you can about your particular case.
Other Treatments
An assortment of other treatments are commonly used when a brain tumor fails to respond to surgery, radiation, or chemotherapy. These involve the use of angiogenesis inhibitors—drugs that disrupt the blood vessels in a tumor, thereby cutting off a tumor's supply of nutrients and oxygen; differentiating agents—drugs that convert dividing cancer cells into mature, nondividing cells, thereby stopping further tumor growth; immunotherapy—various techniques that attempt to boost a person's immune system so that it more effectively fights the tumor cells; and gene therapy—inserting genes into tumor cells or the immune system to change the way the tumor cells operate.
Because of the effect that a brain tumor or treatment has on how a person functions, rehabilitation is an important part of recovery. Occupational rehabilitation involves restoring normal daily functioning, from working with one's hands to driving. Physical therapy involves improving a strength and motor function. Speech and language therapy may be important for restoring the ability to speak clearly. Cognitive therapy may be important for helping one deal with short-term memory loss.
There are specialists available to help with vision, balance, or facial paralysis problems. Sometimes patients need vocational therapy to help them return to the working world.
It is a good idea to look for a support group and/or a counselor or psychotherapist to help deal with the stress and emotional challenges of living with, and recovering from, a brain tumor. Maintaining a positive attitude and taking care of one's emotional well-being are very important. It is improtant to exercise and a establish a healthy diet in order to feel well.

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