Cancer causes pain. Although studies give varying results, even the most conservative studies report that at least 20% of patients have pain at diagnosis or in the advanced stages of their illness. Numerous studies show that clinicians often undertreat cancer pain and that undertreated pain causes undue burdens on patients and their families. Clinicians may underestimate how much pain patients feel, or not be facile in pain management techniques that have the potential to greatly improve a patient's quality of life. Patients’ misconceptions about pain medications also contribute to inadequate pain management. Patients may be reluctant to take pain medications for fear of addiction or worry that requiring pain medication indicates that death is imminent. Patients at particular risk for undertreatment include women, minorities, the poor, and the old (1).
With simple treatments, more than 80% of patients can have their pain controlled (2). The first step in devising a pain management plan requires the patient to characterize the pain. It is helpful to distinguish neuropathic pain, which patients will characterize as burning, sharp, or shooting, from visceral and somatic pains, which are dull and aching. In a cancer patient, pain is usually caused by chemotherapy, radiation therapy, or tumor recurrence (3). Understanding the origin of the pain aids in the development of the appropriate pain management plan. Pain from bony metastases, for example, may require an NSAID or radiation, whereas pain from a local recurrence outside of the bone may require only opioids.
The next step is to assess the baseline level of pain using simple, validated methods such as visual analog scales, numerical scales (e.g., from 1 to 10), or pictoral scales (faces, circles of different colors). Many clinicians are unaware that patients with chronic pain will often lack physiologic signs that may indicate pain. Patients with chronic pain rarely show signs of sympathetic arousal such as tachycardia or hypertension. Patient self-report is the gold standard of pain assessment.
A patient's experience of pain is not limited to physical sensation. Depression, anxiety, and existential distress can all exacerbate a patient's perception of and ability to cope with pain. Because psychosocial and spiritual factors play such a large role in a clinician's ability to treat pain, it is critical to include assessment of these factors when developing a comprehensive pain management plan. The comprehensive clinical assessment should therefore include the following:
Psychological, social, financial, and spiritual sources of coping and of distress
An assessment of mood disorders: screen for and treat depression and anxiety
Evaluating how the patient and family are coping with the illness
The goal of treatment is to adequately manage the pain while trying to minimize toxicity. For moderate pain or pain that persists despite NSAIDs or acetaminophen, it is appropriate to initiate ...