Lung cancer pain

The majority of patients who acquire lung cancer will have troublesome symptoms at some time during the course of their disease. Some of the symptoms are common to many types of cancers, while others are more often encountered with lung cancer than other primary sites. The most common symptoms are pain, dyspnea, and cough. This document will address the management of these symptoms, and it will also address the palliation of specific problems that are commonly seen in lung cancer: metastases to the brain, spinal cord, and bones; hemoptysis; tracheoesophageal fistula; and obstruction of the superior vena cava.

Key words: bone metastases; brain metastases; dyspnea; hemoptysis; interventional bronchoscopy; pain management; pleural effusions; spinal cord metastases; superior vena cava syndrome; tracheoesophageal fistula

Abbreviations: AHCPR = Agency for Health Care Policy and Research; APC = argon plasma coagulation; EBB = endobronchial brachytherapy; NSAID = nonsteroidal anti-inflammatory drug; NSCLC = non-small cell lung cancer; PDT = photodynamic therapy; RCT = randomized controlled trial; SCLC = small cell lung cancer; SVC = superior vena cava; TEF = tracheoesophageal fistula; WBRT = whole-brain radiation therapy

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Since the vast majority (86%) of patients with lung cancer will die from their disease, it is intuitively obvious that most such patients will have one or more symptoms during the course of their disease. These symptoms produce a clinically significant alteration in quality of life, and--for many of the symptoms and the specific problems that the symptoms represent--a shortening of the quantity of life. Symptoms that may require palliation include those attributable to the primary lung cancer itself (dyspnea, hemoptysis), regional metastases within the thorax (superior vena cava [SVC] syndrome, tracheoesophageal fistula [TEF], pleural effusions), or from metastases to distant sites (brain, spinal cord, bone). Pain is an ever-troublesome symptom for many patients with lung cancer. Clinicians experienced in managing patients with lung cancer must be conversant with the many different ways to palliate the symptoms that may occur with lung cancer.

This section of the evidence-based guidelines is based on an extensive review of the medical literature. The Agency for Health Care Policy and Research (AHCPR) guidelines for the management of cancer pain was used in an abbreviated form for the guidelines regarding management of pain in lung cancer. Randomized controlled trials (RCTs) have generally not been done for most aspects of palliative care in lung cancer specifically, and meta-analyses are not available. Three RCTs were identified that studied surgical resection for brain metastases and whole-brain radiation therapy (WBRT) for brain metastases. One RCT was identified that studied the effect of corticosteroids in bone metastases, spinal cord compression, and brain metastases, respectively. Most reports of the topics considered in this section were case series.

PAIN CONTROL

A comprehensive document for the management of cancer pain was developed and published in 1994 as part of a response to Public Law 101-239 (the Omnibus Reconciliation Act of 1989), under the aegis of the AHCPR. (1) The comments in this section are adapted from that resource, which was written by a multidisciplinary panel of private-sector clinicians and other experts convened by the AHCPR. Explicit, science-based methods and expert clinical judgment were used to develop specific statements. The scope of that effort is beyond what can be discussed in detail in this document, and the reader is referred to that resource for additional information.

The causes of cancer pain include tumor progression and related pathology (eg, nerve damage), surgery, and other procedures used for treatment and diagnosis, toxic side effects of chemotherapy and radiation, infection, and muscle aches when patients limit their physical activity. Approximately 75% of patients with advanced cancer have pain. Failure to relieve pain leads to unnecessary suffering. Decreased activity, anorexia, and sleep deprivation caused by pain can further weaken already debilitated patients.

Effective management of pain from cancer can be achieved in approximately 90% of patients. Proper management of a patient's pain involves more than analgesia, and the program of pain control for any one patient must be individualized. Approaches that may augment analgesia include cognitive/behavioral strategies, physical modalities, palliative radiation and antineoplastic therapies, nerve blocks, and palliative and ablative surgery.

Any analgesic medication program should be kept as simple as possible, both with regard to the frequency and route of administration. Oral medications are preferred, because of convenience and cost-efficacy. If the patient cannot take medications orally, rectal and transdermal routes should be considered because they are relatively noninvasive. IM routes of administration should be avoided because of the associated pain and inconvenience, and also because of unreliable absorption.

A nonsteroidal anti-inflammatory drug (NSAID) or acetaminophen should be used, unless there is a contraindication to their use. If pain persists or becomes worse, an opioid should be added and not substituted. Using opioids and acetaminophen or NSAIDs often provides more analgesia than can be accomplished by either class of drug alone. Further, the use of acetaminophen or NSAIDs may have a dose-sparing effect for opioids, which can provide the benefit of fewer side effects from the opioids. When pain persists despite this approach, the dose of opioids should be increased or a more potent agent chosen. The World Health Organization ladder has been shown to be an effective method to ensure the rational titration of therapy for cancer pain (Fig 1). (2)

Morphine is the most commonly used opioid for moderate or severe pain. It is available in a wide variety of dosage forms that include immediate and controlled-release preparations. Morphine is relatively inexpensive. Transdermal and rectal routes of administration can be used for most patients who cannot receive medications orally. Morphine, hydrocodone, and oxymorphone suppositories are available. Fentanyl is the opioid most frequently used for transdermal administration. Meperidine should not be administered if it is anticipated that there will be a continuous need for opioid medication. It has a short duration of action, and its metabolite, normeperidine, is toxic and causes CNS stimulation with dysphoria, agitation, and seizures.

Both the cancer patient and family members may shun the use of opioids because of a fear of addiction. Physicians must educate both the patient and the family about pain and how it is to be managed as part of the treatment plan. Effective pain control begins by asking the patient about pain. An easily administered pain rating scale should be used for assessment of pain, both at the time of initial presentation and periodically at regular intervals during the course of the disease. The most common pain scales are numeric (0 to 10 pain intensity), simple descriptive in nature (no pain, mild, moderate, severe), and a visual analog scale.

Analgesic medications should be administered around the clock with extra doses on an as-needed basis, as this approach helps to prevent recurrence of pain. A written pain management plan should be given to the patient with cancer pain. Constipation is a side effect of opioid medications. Constipation should be anticipated, treated prophylactically, and monitored constantly. Mild constipation can be managed by an increase in fiber consumption and a mild laxative such as milk of magnesia. Bulk-forming laxatives such as fiber supplements should be avoided. Unless there are contraindications, cathartic agents should be administered on a regular schedule.

Adjuvant drugs may be used to enhance the efficacy of opioids. Corticosteroids produce effects that include mood elevation, relief of inflammation, and reduction of cerebral or spinal cord edema when there is intracranial metastasis or spinal cord compression. Anticonvulsants such as phenytoin, carbamazepine, and clonazepam are used to manage neuropathic pain. Tricyclic antidepressants are used as an adjuvant to analgesics for the management of neuropathic pain. They augment the effects of opioids and have innate analgesic properties. Their mood-elevating properties may be helpful as an adjuvant to strict analgesics. Other adjunctive pharmacologic approaches include neuroleptics such as the major tranquilizers, hydroxyzine, bisphosphonates, and calcitonin for bone metastases.