Page 159 Guide to Pain Management in Low-Resource Settings

Chapter 19

Osseous Metastasis with Incident Pain

M. Omar Tawfi k

What is incident pain? Is it How common is osseous
diff erent from breakthrough pain? metastasis?

Incident pain is an episodic increase in pain intensi- Bone metastasis in cancer patients is seen frequently. It
ty. Some include incident pain as a subtype of break- is the third most common metastatic site after the lung
through pain (BTP), while others defi ne BTP as one and liver. Myeloma is the hematological malignancy
of the subtypes of incident pain. BTP is defi ned as “a most frequently associated with lytic bone lesions. Bone
transient increase in pain to greater than moderate in- metastases are more often seen with cancer of the lung
tensity, which occurred on a baseline pain of moderate and the prostate in males and cancer of the breast in fe-
intensity or less.” males; up to 85% of patients dying from breast, prostate,
Th e term BTP can only be used when base- or lung cancer demonstrate bone involvement at autopsy.
line pain is controlled by analgesics. However, there is Th e most common cancer that produces pain metastasis
no general agreement on the defi nition of BTP. In the is breast cancer, and the most common site is vertebral
United Kingdom the term is often used synonymous- bodies, as seen in Table 2. Twenty-fi ve percent of patients
ly with end-of-dose failure. However, there is a gen- have multiple sites of pain, and 10% of patients with spine
eral agreement that BTP in cancer patients may occur pain have been found to have epidural cord compression.
spontaneously. When it is precipitated by an event, it
can be defi ned as incident pain. Precipitating events Are all osseous metastases similar?
may be volitional and related to movements, walking,
coughing, sitting, standing, or even touching. BTP Osteolytic bone disease is the major source of pain. It
usually occurs at the same site as the background pain, causes diffi culty in ambulation or immobility, neuro-
while incident pain may occur at the site or in a diff er- logical defi cits, and pathological fractures. Pathologi-
ent place when there is widespread osseous metastasis. cal fractures due to increased bone fragility have been
Th e onset, duration, and frequency of BTP dif- reported to occur in 8–30% of patients with bone me-
fer. Th e duration may vary from minutes to hours It tastases. Fracture is common in patients with a my-
has been estimated to be 15–30 minutes on average, eloma and breast cancer, and long bones are more fre-
with a frequency of 4–7 pain episodes per day. quently involved.

Guide to Pain Management in Low-Resource Settings, edited by Andreas Kopf and Nilesh B. Patel. IASP, Seattle, © 2010. No responsibility is assumed by IASP 147
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