Assessment of cancer pain
The management of cancer pain depends on a
comprehensive assessment that characterises the symptom
in terms of phenomenology and pathogenesis, assesses the
relation between the pain and the disease, and clarifies the
impact of the pain and comorbid conditions on the
patient’s quality of life. This assessment requires the use
of a standard nomenclature and an approach that explores
the many dimensions of pain and other features of cancer.
Because pain is inherently subjective, a patient’s selfreport
is the gold standard for assessment. The
information elicited from the patient should focus on:
temporal features (onset, pattern, and course); location
(primary sites and patterns of radiation); severity (usually
measured with a verbal rating scale, eg, mild, moderate, or
severe, or a 0–10 numeric scale); quality; and factors that
exacerbate or relieve the pain. These characteristics,
combined with information from the physical examination
and review of laboratory and imaging studies, usually
define a discrete pain syndrome, clarify the known extent
of disease and the relation between the pain and specific
lesions, and allow inferences about pain pathophysiology.
This information influences the decision to undertake
further assessments or attempt specific therapies.
In the past few years, inferences about the
pathophysiology of pain have informed therapeutic
decision making. The term nociceptive is applied to pains
that are presumed to be maintained by continual tissue
injury. Nociceptive pain is called somatic when the
continued activation is related to primary afferent nerves
in somatic tissues, such as bone, joint, or muscle, and is
called visceral when viscera afferents are activated by
i n j u r y .