Copyright 2009 by the Society for Neuro-Oncology
Quality of life is an important area of clinical neurooncol-
ogy that is increasingly relevant as survivorship increases
and as patients experience potential morbidities associ-
ated with new therapies. This review of quality-of-life
studies in the brain tumor population aims to summarize
what is currently known about quality of life in patients
with both low-grade and high-grade tumors and suggest
how we may use this knowledge to direct future research.
To date, reports on quality of life have been primarily
qualitative and focused on specific symptoms such as
fatigue, sleep disorders, and cognitive dysfunction, as
well as some symptom clusters. However, the increasing
interest in exploring quality of life as a primary end point
for cancer therapy has established a need for prospective,
controlled studies to assess baseline and serial quality-of-
life parameters in brain tumor patients in order to plan
and evaluate appropriate and timely interventions for
their symptoms. Neuro-Oncology 11, 330–339, 2009
(Posted to Neuro-Oncology [serial online], Doc. D08-
00197, November 10, 2008. URL http://neuro-oncology
.dukejournals.org; DOI: 10.1215/15228517-2008-093)
Keywords: brain tumor, clinical trial end points, quality
of life, survivorship, symptom management
faction with life. QOL is a broad term that involves sev-
uality of life (QOL) is a concept that encom-
passes the multidimensional well-being of a
person and reflects an individual’s overall satis-
Quality of life in adults with brain tumors:
Current knowledge and future directions
Raymond Liu, Margaretta Page, Karla Solheim, Sherry Fox, and Susan M. Chang
Department of Neurological Surgery, University of California, San Francisco, San Francisco, CA (R.L., M.P.,
K.S., S.M.C.); and Cullather Brain Tumor Quality of Life Center, Bon Secours Richmond Health System/
St. Mary’s Hospital, Richmond, VA (S.F.); USA
Received July 23, 2008; accepted October 14, 2008.
Address correspondence to Susan M. Chang, Department of
Neurological Surgery, University of California, San Francisco, 400
Parnassus Ave., A-808, San Francisco, CA 94143-0350, USA
eral dimensions, including physical or functional status,
emotional well-being, and social well-being.1
Patients with primary brain tumors face serious chal-
lenges to their QOL. They have difficulties with gen-
eral symptoms such as headache, anorexia, nausea, sei-
zures, and insomnia. These patients also face symptoms
secondary to focal neurologic deterioration, including
motor deficits, personality changes, cognitive deficits,
aphasia, or visual field defects.2,3
Despite these many challenges, there are few well-
tested interventions to improve QOL and no established
systematic way to study it in these patients. Few ade-
quately controlled or powered studies have addressed
QOL, and clinical guidelines are limited on how to man-
age symptoms in primary brain tumor patients. This
review summarizes what is currently known about the
QOL of adult primary brain tumor patients, the chal-
lenges to QOL research, and future directions for QOL
research in brain tumor patients.
QOL in Brain Tumor Patients:
The overall symptom burden and disability for glioma
patients are significant, especially in those with high-
grade or recurrent disease.3,4 Malignant glioma patients
score significantly lower in all domains of functioning
compared to age-matched and sex-matched healthy
controls and have lower social functioning and more
problems with vision, motor functions, communication,
headaches, and seizures than do matched, non-small-cell
lung cancer patients.5 Patients with high-grade tumors
do not appear to differ in QOL between those with grade
III and grade IV tumors,3,6–8 although perceived QOL
in patients with grade III tumors may be better.9 The
Liu et al.: Quality of life in adults with brain tumors
Neuro-oNcology • J U N e 2 0 0 9 331
difference in QOL may be less dependent on the grade
of tumor and more dependent on whether the tumor is
stable or progressive. For example, one study found that
patients with malignant gliomas with low QOL at base-
line tended to deteriorate over time.10
Patients with low-grade glioma also have a signifi-
cant symptom burden.11 In one study, 45% of patients
with low-grade glioma reported low overall QOL, with
fewer than half able to carry out normal activities with-
out restriction. Fatigue, sleep disturbance, and pain were
the most frequent symptom complaints, but patients also
had difficulties with other realms of QOL, including
difficulties with cognitive and emotional dimensions.12
Compared to control groups of patients with non-CNS
cancers and healthy patients, low-grade glioma patients
specifically report more fatigue, cognitive dysfunction,
and altered mood states.11,13–15 The prognostic signifi-
cance of symptom burden in low-grade glioma patients
is unclear because studies have shown contradictory
Research addressing specific symptoms that affect QOL
has focused on fatigue, sleep, pain, seizures, mood dis-
turbance, and cognitive function. This research has been
mostly descriptive, and most studies examine a hetero-
geneous group of patients receiving different therapies at
different stages of their illness.
Fatigue appears to be the most significant symptom
facing patients with high-grade gliomas3,6 and may be
more significant a problem compared to patients with
low-grade tumors.18 In patients with recurrent malig-
nant gliomas, the incidence of fatigue may approach
89%–94%.3 In a study evaluating patients with high-
grade gliomas enrolled in three phase II protocols, sig-
nificant fatigue was found in one-third of patients and
independently predicted poorer overall survival.6 In that
study, Eastern Cooperative Oncology Group perfor-
mance status was correlated with overall QOL, exces-
sive daytime somnolence, and increased fatigue. For
low-grade glioma patients, one small study showed that
of all QOL variables tested, fatigue had the strongest
relationship with overall QOL.12
Sleep disturbance is also a common problem in pri-
mary brain tumor patients.12,19 For example, one study
evaluating the incidence of major depressive disorder
in a neurooncology clinic showed some type of sleep
disturbance in 31.6%–52% of the patients evaluated.19
Other patient series suggest that high-grade glioma
patients may have an even higher prevalence of sleep
Pain is another symptom that glioma patients often
face.21 Headache is the most common type of pain,
which more than 50% of patients with high-grade
gliomas experience.3 Unfortunately, studies to date have
not examined the type, location, or intensity of headache
pain, the distress it caused, or its overall relationship to
QOL in brain tumor patients.
Seizures in glioma patients are associated with dete-
rioration in multiple cognitive domains.13 Low-grade
glioma patients may have a higher incidence of epileptic
seizures than do high-grade glioma patients, and in one
study, antiepileptic therapy was able to control seizures
only in approximately 50% of patients.13 The pres-
ence of seizures has not been shown to be a prognostic
factor in some studies17 and was a positive prognostic
factor in other studies when no other symptoms were
Studies on mood disturbance in brain tumor patients
have reported varying results, noting depression in any-
where between 7.9% and 90% of cases8,19,24–26 and sig-
nificant anxiety in 29%–60% of cases.8,25,27 The use
of formal criteria from the Diagnostic and Statistical
Manual of Mental Disorders, 4th edition, was employed
in only a few studies to study depression.19,26 Of note, in
some cohorts of primary brain tumor patients, depres-
sion was the most important independent predictor
of QOL28,29 and has been shown to have an adverse
impact on survival.26,30,31 Depression may also be under-
treated. For example, in one study, only 60% of patients
reported by their physicians to be depressed received
Depression and anxiety may both have biologic foun-
dations in brain tumor patients. In particular, measur-
able serotonin binding sites and strong peripheral benzo-
diazepine receptor expression were present in the tumors
of rats implanted with gliomas.32 Expression of certain
serotonin receptors has also been found in human fetal
astrocytes and glioma cell lines.33 The biologic connec-
tions between tumor and symptoms could suggest that
symptoms in some cases may not only be prognostic, but
may be a surrogate marker for disease.
Cognitive functioning has also been studied in brain
tumor patients and has been recently reviewed.34 Malig-
nant glioma patients, in particular, deal with a signifi-
cant burden in terms of cognitive dysfunction, with
as many as 49% experiencing cognitive impairment.5
In smaller trials, there is evidence that cognitive dys-
function is present even prior to treatment.35 There is
an unmet need for early neurocognitive evaluation and
intervention. In addition, the prevalence of neurocogni-
tive dysfunction has implications for decision making
and informed consent.
Evaluation of cognitive function also has prognostic
value.9,36,37 For example, one study of recurrent malig-
nant gliomas showed that cognitive deterioration may
precede radiographic evidence of progression by almost
6 weeks.36 A simple screening examination such as the
Mini Mental Status Examination (MMSE) can have
prognostic significance in glioma patients.38–40 However,
while the MMSE is feasible and convenient to use in brain
tumor patients, it has not consistently been shown to
detect cognitive decline in brain tumor patients.6 More-
over, the test has been validated for dementia screen-
ing but does not have a high degree of sensitivity for
other cognitive domains.41 New neuropsychologic tests
need to be validated in this population, because many
of the standard tests lack sensitivity, especially at the
lower end of the impaired range.42 In fact, attempts are
being made in large cooperative trials to standardize the
Liu et al.: Quality of life in adults with brain tumors
332 Neuro-oNcology • J U N e 2 0 0 9
patients with glioblastoma surviving for more than 5
years found that depression or anxiety affected a signifi-
cant proportion of the patients (4 of the 10 patients).50
Larger prospective studies are needed to better describe
the long-term QOL of brain tumor patients. The urgent
need for research in this field is driven by the growing
population of brain tumor survivors.
A Common Etiology to Symptoms:
Although symptoms have been studied separately, they
are often interrelated and may in some cases have a com-
mon etiology. The interrelationship between symptoms
has been studied in the symptom cluster literature.52,53
In general cancer patients, anxiety, depression, pain,
fatigue, and sleep disturbance have been consistently
studied as potential components of symptom clusters,
and studies have found relationships among these symp-
toms in various configurations.53 Research specifically
concerning symptom clusters in primary brain tumor
patients has been extremely limited. In a high-grade
glioma study, depression, fatigue, sleep disturbance, and
cognitive impairment formed a symptom cluster that
explained 29% of the variance in QOL, and depression,
fatigue, sleep disturbance, cognitive impairment, and
pain formed a symptom cluster that explained 62% of
the variance in functional status.54
Cognitive function has been correlated to increased
fatigue and depression in newly diagnosed malignant
glioma patients.6 Performance status was also strongly
correlated with cognitive function, as measured by the
MMSE, in one study evaluating two large, prospective,
randomized trials of newly diagnosed malignant glioma
patients.55 Fatigue, in turn, may be related to other
aspects of QOL and was found to have negative effects
on all components of QOL in glioblastoma patients,
with the exception of nutritional well-being.56
The etiologies of specific clusters of symptoms are
generally unknown. Expression of proinflammatory
cytokines such as tumor necrosis factor-a, interleukin-1,
and interleukin-6 has been proposed as one mechanism
for common symptoms.52,53 Support for this hypothesis
is provided by studies that show an elevation in fatigue,
anxiety, sleep disturbance, and pain sensitivity when
these cytokines are introduced into animal models.52,53
Increased levels of these cytokines are also seen in
depressed patients and cancer patients with fatigue.52,53
Although there is some evidence that cytokines contrib-
ute to symptom clusters, it is very possible that other
explanations exist, or that clustered symptoms do not
share a common etiology.53 Other biologic mechanisms
for symptom clusters are being studied as well. For
example, the symptom cluster of fatigue, appetite loss,
and sleep disruption may result from interference by
epidermal growth factor receptor (EGFR) ligands with
the hypothalamic modulation of circadian rhythms,
as EGFR ligands and members of the EGFR fam-
ily are overexpressed in tumor cells.52 More research
needs to be done on biologic mechanisms of symptoms
measurement of cognitive status. Numerous brain stud-
ies being conducted by cooperatives such as the Radia-
tion Therapy Oncology Group are using well-known
tests of neurocognitive function, such as the Hopkins
Verbal Learning Test, the Trail Making Test, and the
Controlled Word Association Test.
In summary, brain tumor patients deal with a signifi-
cant symptom burden. The main areas of concern are in
fatigue, sleep, pain, seizures, mood, and cognitive func-
tion. Malignant glioma patients are particularly affected
by fatigue, whereas low-grade glioma patients have a
large symptom burden from seizures. Further research
is necessary not only to better define this symptom bur-
den, but also to examine individual symptoms within
Long-Term Symptoms: Survivorship
The current literature on survivorship in brain tumor
patients consists of small, mostly retrospective, noncon-
trolled studies. Moreover, they follow patients over vary-
ing amounts of time.43 Patients in survivorship studies
are also highly selected, as they tend to be young, have
high pretreatment performance status, and often have
had a gross total resection of their tumor. Prospective
studies evaluating survivorship would be ideal, but these
studies pose special difficulties because compliance with
self-reported questionnaires declines over time, with the
sickest patients unable to complete follow-up. For exam-
ple, one study following neuropsychologic impairments
in adults with brain tumors showed heterogeneous
results, with only 5 of 49 patients completing the third
Despite the many limitations on survivorship studies,
there is some indication that long-term survivors may
have acceptable long-term QOL. When compared to a
heterogeneous group of inpatients with chronic neuro-
logic diseases, patients with malignant brain tumors had
comparable levels of QOL, and 73% of them were able
to continue or resume previous work activity.45 Other
studies have found that between 44% and 60% of
patients were able to go back to work, although mostly
on a part-time basis.46 In a study of interstitial implan-
tation of brachytherapy, survivors of recurrences were
generally able to maintain their functional status, as
measured by KPS.47
The most serious challenge survivors of brain tumors
face may be cognitive dysfunction, and this is especially
true for patients with malignant glioma.42,43,48–50 Cogni-
tive decline was found in 50% of glioblastoma patients
surviving up to 6 years.48 Cognitive deficits have been
noted on formal testing of supposedly symptom-free
survivors of malignant brain tumors, suggesting that
cognitive deficits may be present even in those patients
without overt evidence of impairment.51 However,
malignant glioma survivors may still report experienc-
ing good overall QOL despite suffering from cognitive
Survivors of malignant gliomas also deal with sig-
nificant mood disturbance. A small study examining 10
Liu et al.: Quality of life in adults with brain tumors
Neuro-oNcology • J U N e 2 0 0 9 333
to better understand the connection between symp-
toms and tumor factors and to develop better targeted
Despite the significant burden of symptoms that brain
tumor patients face, few QOL interventions have been
tested in brain tumor patients. Of all symptoms, inter-
ventions for fatigue and cognitive dysfunction have been
the most widely studied. A phase II study of donepezil
in 24 irradiated brain tumor patients showed statisti-
cally significant improvements in cognitive functioning,
mood, and health-related QOL.57 Methylphenidate has
also been used to improve cognitive dysfunction and
fatigue. In a pilot study, methylphenidate improved
cognitive function and fatigue in patients with brain
tumors.58 A randomized trial of methylphenidate in
a heterogeneous population of brain tumor patients
receiving radiation therapy was closed early due to
lack of accrual, high dropout rates, an interim analy-
sis showing no effect, and withdrawal of drug company
support.59 Modafinil is another wake-promoting agent
used for fatigue, although no large-scale studies have
been performed in brain tumor patients. A pilot study of
modafinil in brain tumor patients showed some improve-
ment in cognitive, mood, and fatigue outcome measures,
although the study randomized patients to two different
doses of modafinil rather than to placebo.60
Nonpharmacologic interventions such as exercise
are thought to potentially improve QOL outcomes, as
well, and will likely be tested in brain tumor patients in
the near future.61 Complementary alternative medicine
(CAM) is also commonly used, although studies to date
have failed to show a clear correlation between use of
CAM and improved QOL.62,63 In addition, cognitive
training modules have been developed and tested in non-
cancer patients64 and will likely be tested in brain tumor
patients in the future.
A Model for Future QOL Research
Because of the difficulty of studying symptoms that
may have many potential contributing etiologies, better
research models are needed to understand what contrib-
utes to decreased QOL and symptom burden in order
to develop targeted interventions to improve patients’
QOL. Figure 1 describes one way of examining the indi-
vidual contributions to a patient’s overall QOL. Patient
factors that can contribute to QOL include demographic
characteristics and comorbidities that may affect a
patient’s perception and symptom experience. Tumor
factors include tumor laterality, size, and location,
which may, in brain tumor patients, affect the specific
neurologic symptoms they experience. Finally, treatment
factors include surgery, radiation, chemotherapies, and
concomitant medications that can cause or relieve symp-
toms that affect QOL.
Studies focusing on brain tumor patient comorbidities
and demographics and their effects on QOL are largely
lacking. Gender differences in brain tumor patients’
reported QOL have been the most studied patient fac-
tor, although results have been mixed. A correlation
between lower QOL scores and being female has been
shown in several studies,29,65 although not in others.6,12
Higher levels of mood disturbance have been found in
women with brain tumors than in men,66,67 but not in
all studies.25 The etiology of this proposed difference
remains unexplained, but reporting bias could certainly
Tumor location and laterality has been shown to be cor-
related to several specific symptoms in some studies but
not in others. Because patients with tumors in the left
hemisphere may have greater problems with communi-
cation even before treatment is initiated,35 the reliability
of conclusions about laterality based on self-reported
symptoms and QOL is sometimes in question.
Mood changes may be affected by lesion location. For
example, depression may arise from left brain injury,67
and anxious states may arise from right brain injury.68
Depression may also be more frequent in malignant
glioma patients with left-hemisphere tumors.7 Another
study showed that patients with a right-hemisphere pri-
mary brain tumor had statistically significantly higher
mean anxiety scores, which improved 3 months and
1 year after surgical resection.67 Low-grade glioma
patients with lesions in the ventral frontal cortex or
lesions in the temporoparietal cortex were reported to
have statistically significantly worse mood states after
surgery than those patients with lesions in other regions
of the brain.69
Cognitive function may also be related to tumor
laterality. For example, left-hemisphere tumors have
Tumor Factors Treatment Factors
Fig. 1. Model to evaluate effects of different factors on brain tumor
patients’ overall quality of life (QOL).
Liu et al.: Quality of life in adults with brain tumors
334 Neuro-oNcology • J U N e 2 0 0 9
in general been associated with lower scores on ver-
bal tests,7 while right-hemisphere lesions have been
related to lower scores on facial recognition tests.70 In
another study, cognitive functioning in patients referred
for neuropsychiatric evaluation was poor but was bet-
ter in younger patients and in those with frontal brain
tumors.71 In low-grade glioma patients, greater cogni-
tive disability has been noted in those with tumors in
the dominant hemisphere.11,15 Patients with tumors in
the left hemisphere report more difficulty concentrat-
ing than do patients with right-hemisphere lesions,2,11
although patients with right-hemisphere lesions report
more tension.11 The effect of tumor laterality may dif-
fer between brain tumor patients and other populations.
For example, one small study compared 17 brain tumor
patients to 17 stroke patients with similar laterality and
found that these two populations differed tremendously
in their neuropsychologic profiles. In this study, brain
tumor patients tended to have more global cognitive
deficits compared to the site-specific deficits apparent
in stroke patients.72 Tumor progression may have more
of an impact on declining cognitive function in patients
than do treatment factors such as radiation,38 but the
difficulty in separating these effects often makes it dif-
ficult to attribute symptomatic progression to a single
Treatment factors that can affect brain tumor patients’
overall QOL include surgery, radiation, chemotherapy,
and concomitant medications. Relationships between
QOL and these treatments have been studied, although
they suffer from lack of adequate power and control
In surgical series of high-grade glioma patients, the
extent of resection may correlate with QOL outcomes,
with biopsy patients having worse QOL than those who
have undergone gross total resection.5,10,15,26 Unfortu-
nately, selection bias of patients who undergo either a
gross total resection or a biopsy based on factors such
as tumor size, multifocality, location, and functionality
may confound these findings.
Radiation therapy may adversely affect QOL in brain
tumor patients by leading to increased fatigue in the
short term and by contributing to cognitive dysfunction
in the long term. Both radiation-induced fatigue and
cognitive dysfunction have been reviewed in the litera-
ture.73,74 One extensive review of clinical studies pub-
lished on the neurobehavioral sequelae of therapeutic
cranial irradiation in adults found significant cognitive
deterioration in at least 92 of 748 patients reviewed.73
In long-term survivors who received radiation therapy,
cognitive functioning was more significantly impaired
in those that had received whole-brain irradiation com-
pared to focused radiotherapy.74 Although these studies
attribute cognitive decline to treatment effect, it is often
difficult to differentiate tumor factors from treatment
factors. For example, some studies show that patients
with tumors have poor QOL regardless of whether
radiation has been administered.11,15 Furthermore,
modern radiotherapy techniques may not cause the
same types of long-term cognitive effects as whole-brain
The few studies that have evaluated chemotherapy-
related QOL suffer from an inability to differentiate
between the effects of chemotherapy and the effects of
other treatments or the tumor itself. The QOL in newly
diagnosed glioblastoma patients receiving either radio-
therapy alone or radiotherapy with concomitant and
adjuvant temozolomide (TMZ) has been reported.20
Both groups were substantially impaired compared to
historical controls, but no significant decrease in overall
QOL was noted throughout treatment. Patients receiving
TMZ had more vomiting, anorexia, constipation, and
decreased social functioning. Fatigue during radiation
therapy was more frequent in those assigned to TMZ.
Not surprisingly, patients who responded to TMZ
reported improvement in multiple domains of QOL.78
Concurrent medication use may confound the study
of therapy-related symptoms. Medications commonly
given to brain tumor patients include seizure medications
and steroids. Both these medications can adversely affect
physical, emotional, and cognitive functioning.79 Anti-
epileptics, in particular, have been linked to cognitive
dysfunction.5,13,15 Analysis of this link is confounded by
whether symptoms are caused by antiepileptics or by sei-
zure activity. Corticosteroids have been linked to depres-
sion in high-grade glioma patients19,26 and to lower sur-
vival in recurrent malignant glioma patients.80
While treatment-related effects on QOL have been
examined, existing studies are often retrospective and
not controlled. In addition, it has not been clear which
concurrent or sequential treatments are affecting QOL
and whether patient factors or tumor factors are con-
tributing to loss of QOL. Further research that accounts
for confounding factors is necessary in order to define
specific treatment-related symptoms and their contribu-
tion to decreased QOL.
Another challenge in QOL research is finding validated
instruments to use. Early QOL reports in brain tumor
patients evaluated only the functional domain of QOL
using KPS scores.81,82 A review of studies up to 1998
in brain tumor patients81 suggests that functional status
as measured by KPS remains high until near the time
of death. KPS generally correlates with overall QOL83,5
and appears to have prognostic value.80 However, using
the KPS to measure QOL is problematic because it is
only a single measurement of functional ability, and its
reliability and validity depend on the observer. Methods
of obtaining more information about a patient’s QOL
include considering the patient’s level of independence,
training observers in KPS measurement,84 and develop-
ing adjunctive questionnaires such as the independent-
living score to corroborate KPS scores.85
More recent studies have assessed the multidimen-
sional aspect of QOL. However, conclusions are still
difficult to make given that the questionnaires are often
Liu et al.: Quality of life in adults with brain tumors
Neuro-oNcology • J U N e 2 0 0 9 335
not validated in the brain tumor population and het-
erogeneous groups of brain tumor patients at all stages
in their disease course are assessed. Attempts to vali-
date questionnaires in the brain tumor population have
been made, but large, well-run studies that employ these
questionnaires remain lacking.86,87
In order to address these questions, new instru-
ments that can measure the multidimensional nature
of QOL in brain tumor patients have been developed.
The two multidimensional QOL instruments that have
been employed most extensively in brain tumor patients
are the Functional Assessment of Cancer Therapy–
Brain (FACT-Br) and the Brain Cancer Module–20
The Functional Assessment of Cancer Therapy–
General (FACT-G) is an instrument that has been used
to measure QOL and has been modified in brain tumor
patients in the FACT-Br.87 In contrast, the BCM-20 is
designed as a supplement to other general cancer-specific
questionnaires.86 It contains questions targeted at four
different areas: future uncertainty, visual disorder, com-
munication deficit, and motor dysfunction. In addition,
it has seven single-item questions that address physical
symptoms regarding headache, seizure, drowsiness, hair
loss, itching, weakness, and loss of bladder function.
Whereas the BCM-20 groups items into four subscales
with symptom domains and additional individual items,
FACT-Br groups all 19 of its brain tumor–specific ques-
tions into a single subscale. The two questionnaires have
not been compared to each other.
Other questionnaires are also being developed.
Recently, a single-item linear analog scale assessment of
QOL in neurooncology patients has been validated. This
simple instrument may allow a quick assessment of the
different dimensions of QOL in brain tumor patients,
especially when further detail into specific areas of QOL
is not the primary objective.88 In addition, the M. D.
Anderson Symptom Inventory Brain Tumor Module is
a validated 22-item questionnaire that identifies spe-
cific symptoms that brain tumor patients face.89 More
research is needed to better utilize existing instru-
ments and to validate new ones in brain tumor patients
designed to answer specific questions.
Other QOL Research Challenges
Additional challenges face investigators interested in pur-
suing QOL research in brain tumor patients. Foremost
among these challenges is finding the right instruments
to measure QOL. There must be a balance between col-
lecting detailed information with well-validated ques-
tionnaires and minimizing questionnaire burden. QOL
studies in brain tumor patients that are prospective,
randomized, and hypothesis driven will allow investi-
gators to pick appropriate instruments that will answer
their specific questions without running into difficulties
with compliance and the hazards of multiple unintended
Questionnaire burden and resulting noncompliance
have been a major problem with existing instruments.
While semistructured interviews may elicit more infor-
mation from patients and caregivers, the interview for-
mat can be quite demanding on the brain tumor popula-
tion.90 Many patients with recurrent malignant glioma
who filled out a baseline FACT-Br questionnaire were
unable to complete it at their first follow-up assess-
ment.36,91 Another study examining longitudinal ques-
tionnaire compliance among newly diagnosed malignant
glioma patients showed that compliance dropped to less
than 50% at 6 months, with administrative failure being
by far the largest reason for failure of compliance.92
One way of improving compliance is by simplifying
the questionnaires; another is by providing more time
for administration. For example, a 10-point Likert scale
with brain tumor-specific questions was investigated
in a preliminary study and found to be feasible in an
unselected brain tumor population.65 Another strategy
to improve compliance has been to use proxy raters.
The reliability of proxy raters has been examined, and
results have been mixed.7 Further study into proxy raters
is needed, and documentation of whether or not ques-
tionnaires were obtained from proxy raters should be
incorporated into QOL studies.
Another challenge with QOL research in brain tumor
patients is related to the potential lack of correlation
between self-reported measures and objective measure-
ments. For example, poor correlation exists between self-
report and objective measures of cognitive functioning
in patients with low-grade tumors15 and in an unselected
population of brain tumor patients prior to treatment.35
The problem of self-reporting cognitive dysfunction is
exacerbated in patients with frontal tumors, who may
underreport cognitive dysfunction due to impaired judg-
ment, or in patients with anxiety, depression, or fatigue
who may overreport cognitive dysfunction.34 Unfortu-
nately, physicians may not be better at determining the
severity of symptoms, and in low-grade glioma patients
may in fact be underestimating the severity of most
Missing data is another major challenge that faces
a QOL researcher. It is critical to document the reason
for missing data and to prospectively design a trial to
account for missing data. One of the dangers of not
adequately considering missing data is that the sickest
patients with the highest symptom burden do not fill out
questionnaires and are underrepresented in studies. This
is a particular challenge with longitudinal QOL studies
in which patients who have the highest symptom bur-
den are often the ones that may find it most difficult to
complete questionnaires. Again, the careful selection of
instruments that have minimal item burden and instru-
ments that still capture the needed data are crucial to the
success of such a study.
Once data are collected in brain tumor patients, they
should be analyzed with consideration for response
shifts. Response shifts are natural changes in a patient’s
perception of their QOL over time in response to
changing internal standards when they are faced with
a life-threatening illness. If these natural changes and
adaptations over time are not considered, data from lon-
gitudinal QOL studies may incorrectly attribute changes
Liu et al.: Quality of life in adults with brain tumors
336 Neuro-oNcology • J U N e 2 0 0 9
in QOL to other external factors. Research on account-
ing for this phenomenon is still ongoing, and models to
account for response shift have been proposed.93
Finally, because the symptoms and realms of QOL can
be interrelated (e.g., insomnia can cause fatigue, which
leads to decreased social interaction), and because an
individual patient is subject to different environmental
and demographic factors that can independently affect
individual symptoms and realms of QOL, the study of
QOL can become quite complex. The large number of
interdependent variables may explain why many QOL
studies have produced mixed results. The best way
to account for these interactions in a trial is to have a
focused question that is prospectively measured and ide-
ally compared between adequately powered randomized
groups in order to reduce the number of confounders.
Several exciting avenues of research remain in the
vastly unexplored area of QOL in brain tumor patients.
Research needs to be performed on validation of easy-
to-use questionnaires and cognitive tests with incorpo-
ration of these instruments into ongoing clinical trials.
Moreover, a better description of longitudinal QOL and
exploration into specific causes of symptoms and sur-
vivorship is necessary. In addition, the significance of
other nontraditional patient factors that contribute to
QOL, such as caregiver, spiritual, and financial aspects
of a patient’s life, need to be better explored. Finally,
once QOL in brain tumor patients has been adequately
described, interventions—both pharmacologic and
nonpharmacologic—are necessary in order to improve
QOL. Ultimately, the exploration of imaging, serum,
genetic, or other biomarkers that can more objectively
quantify symptoms not only will allow the field of QOL
to be more consistently described, but also will likely
have significant diagnostic, prognostic, and treatment
value. While funding may be limited to pursue these
primary QOL research goals, efforts should be made
to incorporate QOL research as secondary end points
into ongoing therapy trials. Few trials have done this to
date,94 although the potential impact of QOL on sur-
vival and prognosis makes incorporation of QOL end
points especially important.95–97
QOL in brain tumor patients is complex and multidi-
mensional in nature, with symptoms having interrela-
tionships with each other as well as patient, tumor, and
treatment factors. Assessing QOL is challenging given
the scarcity of well-validated instruments, difficulty
with compliance especially in longitudinal measure-
ments over time, and the lack of well-designed trials.
Assessing QOL in brain tumor patients is additionally
complicated by the relative rarity of the disease com-
pared to other malignancies, functional limitations to
self-reporting, and concurrent medications such as ste-
roids and antiepileptics.
Despite these limitations, some conclusions can be
made regarding QOL studied to date on brain tumor
patients. Specifically, the burden of symptoms that affect
QOL is significant, but understudied. There are limited
therapeutic options to improve QOL. The incorpora-
tion of QOL as both primary and secondary end points
is crucial because QOL can have prognostic value, and
improvement of QOL may in turn increase overall sur-
vival. As such, QOL should be included as a second-
ary outcome measure and also be tested as a primary
outcome measure in intervention studies designed to
improve the lives of brain tumor patients.
Clearly, more work is needed in the field of QOL in
brain tumor patients. Adequately powered, high-quality
studies from descriptive to diagnostic to interventional
in nature are needed in order to increase both the quality
and quantity of these patients’ lives.
We are grateful to Ilona Garner, Department of Neuro-
logical Surgery, University of California, San Francisco,
for editorial support.
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