BeCOn OWN Educational Program
Modules
Module 1
An introduction to cancer pain
Date of preparation: June 2015 HQ/EFF/15/0024
Contents
Pathophysiology of pain
Types of cancer pain
Incidence, assessment and burden of cancer pain
Challenges in management of cancer pain
Pathophysiology of pain
Pain can be described in two major categories
Acute
pain
Chronic
pain
A protective mechanism that provides survival benefit
or contributes to the healing process
Chronic pain that involves pathology of neural structures
Chronic pain has been defined as a pain that lasts beyond the duration of insult to the body
or beyond the duration of the healing process
Merskey H, Bogduk N. Classification of Chronic Pain: Descriptions of Chronic Pain Syndromes and Definitions of Pain Terms. 2nd ed.
Seattle: IASP; 2012.
National Pharmaceutical Council. http://www.npcnow.org/publication/pain-current-understanding-assessment-management-andtreatments. Accessed 8 Jun 2015.
Classification of pain
Nociceptive
pain
Noxious stimulus
to a tissue (somatic)
or to a visceral organ
(visceral)
Mixed
pain
Pain that is a
combination of
nociceptive and
neuropathic pain
Neuropathic
pain
Arises from abnormal
neural function as a
result of direct damage
or indirect insult to a
neural tissue involved
in pain processing
In cancer, pain can be the presenting symptom of cancer in an otherwise healthy patient or
emerge as disease progresses
http://www.iasp-pain.org/PublicationsNews/Content.aspx?ItemNumber=1673. Accessed 15 Jun 2015.
Classification of pain
Nociceptive pain results from an acute or persistent injury to visceral
or somatic tissues
– Somatic nociceptive pain: site specific, described by patients as “aching”, “stabbing” or
“throbbing” , “tender”, “squeezing” and involves injury to bones, joints, skin, mucosa or muscles
– Visceral nociceptive pain results from injury to organs or viscera, is poorly localised and/or
referred and may be characterised as “cramping” or “gnawing” if it involves a hollow viscus
(e.g. bowel obstruction), or as “aching”, “stabbing” or “sharp” (similar to somatic nociceptive
pain) if it involves other visceral structures such as the myocardium
Neuropathic pain suggests injury to the peripheral or central nervous system.
Neuropathic pain may be associated with referred pain along nerve distribution
(pain is perceived in a location that is not the source of the pain), and all other
descriptors of pain. It is described as “shooting”, “sharp”, “stabbing”, “tingling”,
“ringing”, “numbness”. It is caused by radiculopathy, peripheral neuropathy, phantom
limb, spinal cord compression
Ripamonti CI, Bossi P. Cancer pain. Rehabilitation issues during cancer treatment and follow-up. ESMO Handbook, 2014.
Pain terms
Allodynia: Pain due to a stimulus that does not normally provoke pain
Causalgia: a syndrome of sustained burning pain, allodynia, and hyperpathia after a
traumatic nerve lesion, often combined with vasomotor and sudomotor dysfunction and
later trophic changes
Central neuropathic pain: Pain caused by a lesion or disease of the central
somatosensory nervous system
Dysesthesia: an unpleasant abnormal sensation, whether spontaneous or evoked
Hyperalgesia: increased pain from a stimulus that normally provokes pain
Hyperpathia: painful syndrome characterised by an abnormally painful reaction to a
stimulus, especially a repetitive stimulus, as well as an increased threshold.
Paraesthesia: an abnormal sensation, whether spontaneous or evoked
http://www.iasp-pain.org/Taxonomy. Accessed 15 Jun 2015.
Nociceptive vs. neuropathic pain
Nociceptive
pain
Caused by activity in
neural pathways in
response to potentially
tissue-damaging stimuli
Postoperative
pain
Mixed
Type
Caused by a
combination of both
primary injury and
secondary effects
Arthritis
Mechanical
low back pain
Sickle cell
crisis
Sport/exercise
injuries
Neuropathic
pain
Initiated or caused by
primary lesion or
dysfunction in the
nervous system
Complex regional
pain syndrome
Postherpetic
neuralgia
Neuropathic
low back pain
Distal
polyneuropathy
(eg, diabetic, HIV)
Trigeminal
neuralgia
Central poststroke pain
Cancer pain may be due to a variety of causes
Merskey H, Bogduk N. Classification of Chronic Pain: Descriptions of Chronic Pain Syndromes and Definitions of Pain Terms. 2nd ed.
Seattle: IASP; 2012.
National Pharmaceutical Council. http://www.npcnow.org/publication/pain-current-understanding-assessment-management-andtreatments. Accessed 8 Jun 2015.
Physiology of pain perception
Brain
Transduction
Injury
Transmission
Modulation
Perception
Interpretation
Behaviour
Descending
pathway
Peripheral
nerve
Dorsal root
ganglion
Ascending
pathways
C-fiber
A-beta fiber
A-delta fiber
Dorsal
horn
Spinal cord
Merskey H, Bogduk N. Classification of Chronic Pain: Descriptions of Chronic Pain Syndromes and Definitions of Pain Terms. 2nd ed.
Seattle: IASP; 2012.
National Pharmaceutical Council. http://www.npcnow.org/publication/pain-current-understanding-assessment-management-andtreatments. Accessed 8 Jun 2015.
Nociceptive pain: transmission
Central perception
Cortex
Thalamus
Relay and Descending
Modulation
Brainstem
Transmission
Spinal cord
Conduction
Peripheral stimulus
Signal transduction
Normal pain signalling in the body is transmitted to the spinal cord dorsal
horn through nociceptors.
Fornasari D. Clin Drug Investig. 2012;32 Suppl 1:45-52.
Neuropathic pain: peripheral sensitisation
Mechanical
Chemical
Thermal
P
↑Na+/Ca2+
influx
↑Generator
potential
(membrane
depolarisation)
↑Reach
voltage-gated
sodium channel
threshold
↑Action
potential
PKC activation
Sensitising
agents
PKA activation
Tyr
TrkA
P
Na+
Peripheral sensitisation takes place in inflammatory pain, in some forms
of neuropathic pain and in ongoing nociceptive stimulation
Fornasari D. Clin Drug Investig. 2012;32 Suppl 1:45-52.
Neuropathic pain: central sensitisation
Normal sensory function
AB fibre
mechanoreceptor
Innocuous
stimulus
Na+
channel
Na+
channel
Weak
synapse
Nonpainful
sensation
Increased nociceptor drive leads to central sensitization of dorsal horn neurons
Innocuous
stimulus
Na+
channel
Na+
channel
Increased
synapsis
strength
Central sensitisation occurs in inflammatory,
functional and neuropathic pain
Woolf CJ, et al. Lancet. 1999;353:1959-64.
Painful
sensation
Neuropathic pain, central sensitisation
and inflammation
Neuropathic pain
Central sensitisation
(peripheral nerve damage)
(neuropathic/inflammatory)
a2-AR
+
Nav 1.8
Nav 1.9
Nav b3
TRPV1
ASIC
Nav 1.9
Cava2d1
EP
GABA
Gly
cold, hot,
acid, mechanical
5HT3
a2-AR
NK1
skin
(skin, joint and viscera)
DRG
Cava2d1
Nav 1.8
Nav 1.3
Kv 1.4
TRPM8
DRG
Inflammatory pain
EP
-
PKC/A
TRPV1
P2X3
B1/2
EP
mGluR
+
PGE2
Inflammatory soup
+ NMDA
dorsal horn neuron
Brain (“pain”)
http://www.uq.edu.au/pain-venom/about-pain. Accessed 7 May 2015.
histamine, bradykinin, 5-HT,
H+, prostaglandins, TNFa,
NGF, ATP etc
Types of cancer pain
Chronic cancer pain: tumour-related pain
Somatic pain
Visceral pain
Tumour-related bone pain: directly due
to metastasis itself or oncogenic
hypophosphataemic osteomalacia
Peritoneal carcinomatosis
Tumour-related soft-tissue pain like
pleural pain/ear pain/eye pain
Malignant perineal pain
Paraneoplastic syndromes:
hypertrophic osteoarthropathy, muscle
cramps, Raynaud’s phenomenon
Esin E, Yalcin S. Onco Targets Ther. 2014;7:599-618.
Chronic intestinal obstruction
Ureteric obstruction
Chronic cancer pain: neuropathic pain
Neuropathic pain syndromes
Leptomeningeal metastases
Trigeminal neuralgia
Glossopharyngeal neuralgia
Lumbosacral radiculopathy (damage to nerve root)
Lumbosacral plexopathy (affecting a network of nerves)
Cervical radiculopathy
Brachial plexopathy
Painful peripheral mononeuropathies
Paraneoplastic sensory/motor/autonomic neuropathic pain
Esin E, Yalcin S. Onco Targets Ther. 2014;7:599-618.
Chronic cancer pain: treatment-related pain
Surgery
Chemotherapy
Postmastectomy pain
Painful peripheral neuropathy
Post-thoracotomy pain
Raynaud’s phenomenon
Phantom limb/breast pain
Chronic glucocorticoid-treatment
complications
Pain due to neck dissection
Lymphoedema pain
Radiotherapy
Compression fractures due
to osteoporosis
Targeted therapy-related pain
Late-onset brachial plexopathy
Papulopustular rash
Chronic radiation myelopathy
Erythema
Radiation enteritis
Hand-foot skin syndrome
Lymphoedema pain
Paronychia
Osteoradionecrosis
Fingertip fissures
Radiation dermatitis
Eyelashes growth distortion
Oral and anal mucositis
Abdominal discomfort with diarrhoea
Esin E, Yalcin S. Onco Targets Ther. 2014;7:599-618.
Ripamonti C, et al. Ann Oncol. 2014; 25: 1097-106.
Temporal classification of pain in cancer
ACUTE PAIN follows injury to the body and generally disappears when the body injury heals. It is
usually due to a definable nociceptive cause. It has a definite onset and its duration is limited and
predictable (i.e. pain related to surgery, biopsy, pleurodesis, pathologic fracture, chemotherapy,
radiotherapy, diagnostic and interventional procedures). It is often associated with objective
physical signs of autonomic nervous system activity. Acute pain may also indicate a progression of
disease and is often accompanied by anxiety.
CHRONIC PAIN is due to the presence and/or progression of the disease and/or to treatments (i.e.
chemotherapy-induced neuropathy and/ or osteoporosis, post- surgery, post- radiotherapy).
Chronic pain may be accompanied by changes in personality, lifestyle, and functional abilities and
by symptoms and signs of depression. Chronic pain with overlapping episodes of acute pain (i.e.
breakthrough pain) is probably the most common pattern observed in patients with ongoing cancer
pain. This indicates the necessity for monitoring the intensity of pain and associated symptoms and
the analgesic treatments. Furthermore, the appearance of acute pain, or progression of a
previously stable chronic pain, is suggestive of a change in the underlying organic lesion and
requires clinical re-evaluation.
Ripamonti CI, Bossi P. Cancer pain. Rehabilitation issues during cancer treatment and follow-up. ESMO Handbook, 2014.
Cancer patients may have multiple types of pain
Pain associated with cancer can be understood as multiple types of pain
≈80%
Patients with cancer
have ≥ 2 types of pain
33%
Patients ≥ 4
types of pain
However, patients with cancer can experience non-cancer pain simultaneously
with cancer pain, such as pain from cancer treatment or unrelated conditions
Pergolizzi JV, et al. Pain Pract. 2014 Dec 3. doi: 10.1111/papr.12253. [Epub ahead of print].
Incidence, assessment and burden
of cancer pain
Overall incidence of cancer pain
25 to 30%
of patients with
cancer report pain
at the time of
diagnosis
70 to 80%
of advanced patients with cancer
experience pain over the course
of their disease, which is caused
by tumour infiltration,
treatment, or both
Pergolizzi JV, et al. Pain Pract. 2014 Dec 3. doi: 10.1111/papr.12253. [Epub ahead of print].
Incidence of severe pain is high in ambulatory
patients with newly diagnosed stage IV cancer
Highest pain intensity score within one year of follow-up among newly diagnosed stage
IV cancer patients, according to cancer type (n=505)
None
Low
Moderate
Severe
60
Percentage
50
40
30
20
10
0
Breast
Thoracic
Gastrointestinal
Urogenital
Head and Neck
The incidence of severe pain pain is highest
in gastrointestinal and head and neck cancers
Isaac T, et al. Pain Res Manag. 2012; 17(5): 347–52.
Other
40-year meta-analysis of patients with cancer pain
Pooled prevalence rates of pain
100
90
Patients (%)
80
70
59%
64%
53%
60
50
33%
40
30
20
10
0
Patients after
curative treatment
(95% CI: 21% to 46%)
Patients under
anticancer treatment
(95% CI: 44% to 73%)
Patients characterised
as advanced/metastatic/
terminal disease
(95% CI: 58% to 69%)
Patients at all
disease stages
(95% CI: 43% to 63%)
Of patients with pain, more than one-third graded their pain as moderate or severe
Pooled prevalence of pain was >50% in all cancer types with the highest prevalence in head/neck
cancer patients (70%; 95% CI: 51% to 88%)
CI= Confidence Interval
van den Beuken-van Everdingen MH, et al. Ann Oncol. 2007;18(9):1437-49.
Incidence of pain by cancer type
Cancers involving the pancreas, bone, brain, lymphoma, lung, head and neck
are associated with a pain prevalence >85%
100
93
Percentage patients (%)
90
80
92
90
87
86
86
82
82
73
70
77
77
75
62
60
66
53
50
40
30
20
10
0
Cancer type
Breivik H, et al. Ann Oncol. 2009;20(8):1420-33.
Is pain in patients with haematological
malignancies under-recognised?
The results from Italian ECAD-O survey
Solid tumours 59.4%
Patients with moderate
to severe pain
No pain
Low
16.4
Pts with ST
Haematological cancers 67.3%
Moderate
24.2
26.8
Severe
32.6
Pain in haematological
malignancies deserves
greater consideration
16.3
Pts with HT
0
16.3
20
36.7
40
30.6
60
Percentage
Bandieri E, et al. Leuk Res. 2010;34(12):e334-5.
80
100
Prevalence of pain during the last 3 months
of patients’ lives
Prevalence
of pain
Prevalence of very
distressing pain
%
95% CI
%
95% CI
Head and neck
85.4
64.6-95.0
68.1
48.5-82.8
Oesophagus and stomach
88.4
81.0-93.2
62.9
52.3-72.4
Colon and rectum
84.8
77.7-89.9
64.9
57.3-71.9
Liver and bile ducts
73.7
63.6-81.8
56.1
46.4-65.3
Pancreas
80.3
68.6-88.4
67.0
54.5-77.6
Larynx, lung, and pleura
83.4
76.5-88.6
60.3
54.2-66.1
Breast
75.8
66.4-83.2
52.8
43.8-61.6
Female genital organs
89.9
76.9-96.0
69.2
52.7-82.0
Prostate
90.9
78.5-96.5
58.6
43.5-72.2
Bladder and kidney
89.3
76.1-95.6
70.4
56.6-81.2
Central nervous system
51.9
27.4-75.5
21.1
9.2-42.4
Lymphoma and leukaemia
83.0
73.6-89.5
63.4
53.0-72.7
Multiple myeloma
86.1
66.4-95.1
66.3
41.4-84.6
Other and unspecified
77.6
69.8-83.8
62.9
55.2-70.0
Primary tumour
1,271 oncology patients
with 3 months of life
expectancy.
Pain was seen in:
82.3% of patients
Haematological patients
presented with pain as
frequently as those with
solid tumours
Costantini M, et al. Ann Oncol. 2009; 20: 729-35.
p = 0.098
p = 0.035
Breakthrough cancer pain: a pan-European survey
European survey of 5,084 patients with cancer across 11 countries and Israel
100
90
80
Patients (%)
70
60
69%
56%
50%
44%
50
40
30
20
10
0
Experienced
moderate to severe
pain at least once a
month
Described pain as
severe
Breivik H, et al. Ann Oncol. 2009;20(8):1420-33.
Reported painrelated difficulties
with everyday
activities
Believed that their
quality of life was not
considered a priority
in their overall care
by their health care
professional
The reported prevalence of breakthrough
cancer pain varies widely
Prevalence of breakthrough pain in studies applying standard criteria
for breakthrough pain
Study
Type of population
Prevalence of breakthrough pain
Portenoy & Hagen, 1990
Hospital inpatients (pain team referrals) – USA
n = 90
63%
Fine & Busch, 1998
Hospice homecare patients – USA
n = 22
86%
Portenoy et al, 1999
Hospital inpatients – USA
n = 178
51%
Zeppetella et al, 1999
Hospice inpatients – UK
n = 414
89%
Fortner et al, 2002
Cancer patients (home setting) – USA
n = 1000
63%
The prevalence of breakthrough pain has been reported to be 19–95% amongst various groups of
patients, reflecting differences in the definition and methods utilised, and in the populations studied
Davies A. Cancer-related breakthrough pain. Oxford University Press 2012.
Universal pain assessment tools
Verbal Pain Intensity Scale
No
pain
Mild
pain
Moderate
pain
Severe
pain
Very
severe
pain
Worst
possible
pain
3
4
5
6
Faces Pain Scale – Revised (FPS-R)
1
2
National Pharmaceutical Council. http://www.npcnow.org/publication/pain-current-understanding-assessment-management-andtreatments. Accessed 8 Jun 2015.
Ripamonti CI. Ann Oncol. 2012;23 Suppl 10:x294-301.
Validated assessment tools for the assessment of pain
Visual analogue scale VAS
10 cm
No
pain
Worst
pain
Verbal rating scale VRS
1
No
pain
2
Very
mild
3
4
Mild
5
Moderate
6
Severe
Very
severe
Numerical rating scale NRS
No
pain
0
1
2
3
4
5
Ripamonti CI, et al. Ann Oncol. 2012 Oct;23 Suppl 7:vii139-54.
6
7
8
9
10
Worst
pain
Cancer pain can add additional burden to patients
Cancer pain can be exacerbated by the
normal worries that accompany cancer diagnosis
ANXIETY
DEPRESSION
CATASTROPHISING
HOPELESSNESS
CONCERNS ABOUT
FINANCES
WORRIES OVER
FAMILIAL SUPPORT
Pergolizzi JV, et al. Pain Pract. 2014 Dec 3. doi: 10.1111/papr.12253. [Epub ahead of print].
Cancer pain affects many aspects of daily life
100
90
80
Patients (%)
60
69%
67%
70
52%
51%
50
40
30%
30
20
10
0
Pain impacts
work
performance
Described pain
as distressing
Pain creates
difficulty in
performing
normal activities
in daily life
Breivik H, et al. Ann Oncol. 2009;20(8):1420-33.
Pain stops
them from
concentrating
or thinking
Being in too
much pain
to be able to
care sufficiently
for themselves
BTcP affects all areas of daily life
Interference with various aspects of daily living
2nd quartile
3rd quartile
Enjoyment of life
Sleep
Relations with other
people
Normal work
Walking ability
Mood
General activity
0
1
2
3
4
5
6
7
8
9
10
Numerical rating (0-10)
BTcP has a significant negative effect on quality of life that is related to a direct
effect (suffering) and an indirect effect (interference with activities of daily living)
Study of 1000 cancer patients from 13 European countries.
Davies A, et al. J Pain Symptom Manage. 2013;46(5):619-28.
National Breakthrough Pain Study
Interview of 2198 patients with opioid-treated chronic pain
80% of patients reported BTP
Patients had a median of 2.0 episodes of BTP per day (range, 1-50) and a median
duration of BTP of 45 minutes (range, 1-720)
Compared with patients without BTP, patients with BTP had more pain-related
interference in function, worse physical health and mental health, more disability and
worse mood
BTP is highly prevalent and associated with negative outcomes
Narayana A, et al. Pain. 2015;156(2):252-9.
There are many barriers to better control
of cancer pain
Tendency
to trivialise
pain in light of
seriousness
of cancer
Fear to talk
about pain,
thinking it means
their conditions
is worsening
Failure to
diagnose
breakthrough
pain
Patientrelated
barriers
Unwillingness
to report pain for
any number of reasons,
including not wanting
to distract the doctor
from fighting
the cancer
Lack of
availability of
opioid analgesics
in some
countries/
regions
Clinicianrelated
barriers
Multidisciplinary
teams led by
oncologists who
focus on cancer
treatment and
regard pain
as a secondary
matter
Barriers to
pain control
Healthcaresystem-related
barriers
Inadequate
pain
assessment
Costs
Absence of
national policies
on opioid use and
no prioritisation
of pain control in
public health
Pergolizzi JV, et al. Pain Pract. 2014 Dec 3. doi: 10.1111/papr.12253. [Epub ahead of print].
Rate of undertreated cancer pain (%)
Little progress has been made in adequate
treatment of cancer pain
80
70
60
50
40%
40
33%
30
20
10
0
1994
2012
Year
Pergolizzi JV, et al. Pain Pract. 2014 Dec 3. doi: 10.1111/papr.12253. [Epub ahead of print].
The many consequences of undertreatment
of cancer pain
Insomnia
and
other sleep
disturbances
Profound
fatigue
Anorexia
Physical
consequences
Various
forms of
incapacity
Reduced
cognition
Withdrawal
from social and
familial
interactions
Feelings
of isolation
Psychological
consequences
Reduced
coping skills
Pergolizzi JV, et al. Pain Pract. 2014 Dec 3. doi: 10.1111/papr.12253. [Epub ahead of print].
Suffering
Other
psychological
distress
existential and
spiritual
Challenges in management of cancer pain
Pain management primarily involves
medical oncologists
Other, 5
Physiotherapist, <1
None, 3
Radiation oncologist, <1
Anaesthetist, <1
Don’t know, 1
Nurse/Specialist nurse, 1
Neurologist, 1
Palliative care specialist, 2
Pain specialist, 3
Obstetrician/gynaecologist, 1
Haematologist, 4
General surgeon, 4
Medical doctor, 8
GP/Primary care provident, 19
Breivik H, et al. Ann Oncol. 2009;20(8):1420-33.
Medical oncologist, 42
Patients believe that healthcare providers give
inadequate attention to pain management
60
50%
Patients (%)
50
38%
40
33%
26%
30
20
27%
12%
10
0
HCP does not
consider
patient QoL to
a great extent
HCP does not
recognise pain
as a problem
HCP treats
cancer rather
than pain
Breivik H, et al. Ann Oncol. 2009;20(8):1420-33.
HCP does not
have time to
discuss pain
HCP does not
know how to
control pain
HCP does not
always ask
about pain
A multidisciplinary approach is preferred
in management of cancer pain
NEUROLOGIST
PAIN SPECIALIST
ONCOLOGIST
GENERAL
PRACTITIONER
PALLIATIVIST
RADIOTHERAPIST
Ideally, there should be communication among
the various specialists, with oncologists often
coordinating the patient’s care.
Pergolizzi JV, et al. Pain Pract. 2014 Dec 3. doi: 10.1111/papr.12253. [Epub ahead of print].
Patient adherence to pain guidelines remains
insufficient
In a study of 193 inpatients, 109 met the inclusion criteria of which 70 were
guideline adherent and 39 non-adherent
63% of patients initiated on NCCN adherent guidelines obtained analgesia at 24 hours
vs. 41% in the non-adherent group
Average pain scores across the 24-hour period were lower in the adherent compared
with the non-adherent group (3.5 vs. 4.4)
Chronic home opioid exposure was significantly associated with non-adherent therapy
(OR=3.04; P=0.01) and achievement of analgesia at 24 hours
Mearis M, et al. J Pain Symptom Manage. 2014;48(3):451-8.
Medical oncologists do not always follow practice
guidelines on pain management
In a survey of 268 medical oncologists (24% completers):
– Adherence to the different recommendations of the guideline ranged from 18 to 100%
Adhered to prescribing paracetamol
as first-line pain treatment
94%
Prescribed a laxative in combination with
opioids to prevent constipation
100%
Adhered to the guideline when first-line
treatment had insufficient effect
24%
Adhered to recommendations
for insomnia treatment
35%
Adhered to the recommendation to perform
a multidimensional pain assessment
when disease worsens and pain increases
18%
0
10
20
30
40
50
Percentage
te Boveldt N, et al. Support Care Cancer. 2015;23(5):1409-20.
60
70
80
90
100
Combined pain consultation and pain education
programmes can improve outcomes
In oncology outpatients randomly assigned to SC (n=37) or PC-PEP (n=35):
The overall reduction in pain intensity and daily interference was significantly
greater after randomisation to PC-PEP than to SC (average pain 31% vs. 20%, P=0.03;
current pain 30% vs. 16%, P=0.016; interference 20% vs. 2.5%, P=0.01)
Patients were more adherent to analgesics after randomisation to PC-PEP than
to SC (P=0.03)
PC-PEP improves pain, daily interference and patient adherence
SC, stanard care; PC-PEP, pain consultation and pain education programme
Oldenmenger WH, et al. Pain. 2011;152(11):2632-9.
Summary
Cancer pain may be nociceptive, neuropathic, or mixed
Cancer pain is often under-recognised and undertreated
Cancer pain adds additional suffering to patients, affecting many areas of daily life
More adequate management of cancer pain is needed through a multidisciplinary
approach