Cancer-Related Pain Fraught With Therapeutic and Ethical Complexities

Vitaly Gordin, MD

As long-term cancer survival rates continue to surge, an increasing percentage of patients with cancer-related pain are progressing to the chronic pain arena, which necessitates more contemporary treatment approaches to cancer pain management.

“People used to die in significant numbers after a cancer diagnosis. Now, oncologists and primary care physicians tell them they are lucky they survived, but they still have to deal with multiple-prolonged pain symptoms,”

Vitaly Gordin, MD, director of the Pain Medicine Division at Penn State Milton S. Hershey Medical Center in Hershey, Pennsylvania, said during a session at the American Academy of Pain Medicine 2014 Annual Meeting, held March 6-9, in Phoenix, Arizona. “These patients suffer from pain, yet they are told to be happy because they survived cancer, and that’s a problem.”

Gordin noted that there are different types of cancer-related pain (Table), with syndromes that result from direct tumor involvement as well as from treatment regimens. “The goal should be finding a mechanism-based treatment to cancer-related pain,” he said.

Table. Types of Cancer-Related Pain

• Acute vs chronic

• Nociceptive (visceral and somatic)

—– Arises from activation of perpheral pain receptors (nociceptors) located in all tissues except the central nervous system

• Neuropathic

—– Primary lesion or dysfunction in the central or peripheral nervous system

• Psychogenic

Gordin V. Mechanism-based approach to cancer pain. American Academy of Pain Medicine 2014 Annual Meeting; March 6-9, 2014; Phoenix, AZ.

For example, he said, many factors could play a role in chemotherapy-induced peripheral neuropathy, such as dose intensity, duration of therapy, preexisting conditions, and previous injury to peripheral nerves. Thus far, he said, no drug has proved to prevent chemotherapy-related pain in clinical trials. “In spite of the lack of clear evidence, antidepressants, anticonvulsants, opioids, and topical agents are used by clinicians,” said Gordin.

Ongoing research includes a phase II trial evaluating the antidepressant duloxetine versus placebo in patients who have been treated for stage 0-III breast cancers and experience chronic pain (clinical trial identifier NCT01912612).

Allen W. Burton, MD

In his overview of the prevalence of pain due to cancer, Allen W. Burton, MD, an anesthesiologist with a private pain practice in Houston, Texas, said that “One-third of cancer survivors have ongoing pain symptoms—and one-third of that pain is rated as moderate-to-severe—while two-thirds of progressive cancer patients will experience pain.”

To offer a treatment guideline for such cancer pain, Burton outlined his multimodal approach concerning “which procedures to use and when, but not where.” According to Burton, paravertebral block, epidural injection, adjuvants, and implantable anesthesia delivery systems are effective treatments for acute cancer pain. Gordin, however, noted that “any new onset of pain in a cancer patient should be labeled as a recurrence until proven otherwise.”

For patients with progressive cancer, Burton presented neuraxial infusion therapy, kyphoplasty with coablation of tumors, and neurolytic blocks. However, Burton said, “just like a chronic pain patient, you shouldn’t rush a cancer pain patient to an interventional procedure,” so he recommended turning to that treatment approach only if the patient is refractory to usual pain care, experiences intolerable side effects from analgesics, or has contraindications.

Larry C. Driver, MD

Larry C. Driver, MD, a professor in the Department of Pain Medicine at The University of Texas MD Anderson Cancer Center in Houston, said there are a number of clinical ethical issues to consider in cancer pain management as well. According to Driver, those include:

• The principle of double effect, which provides a framework for clinicians to analyze whether to administer a given therapy when it is impossible to avoid all harmful consequences of that treatment. For example, “in cancer pain management, there may be an unintended side effect of respiratory depression from opioid administration, but the physician’s intention to deliver pain relief would outweigh that potential harm,” said Driver.

• Advance care planning, where a patient designates a medical decision maker in advance through power of attorney, healthcare proxy, or a living will in the event of his or her decisional incapacity.

• Informed consent/refusal, in which adequate and understandable information is disclosed to patients with the capacity for “self-governance, understanding, reasoning, deliberating, and independent choosing.”

• Surrogate decisions, wherein an individual without advanced directive or power of attorney “follows the wishes expressed by the patient when he or she last had capacity; makes decisions based on knowledge of the patient’s values, beliefs, and wishes; and evaluates risks, harms, benefits, and burdens, including pain, suffering, and potential for restoration to ‘health.’ ”

• Medical futility, which could result in disagreement over treatment decisions among the patient, family, and/or healthcare team that fosters uncertainty and may lead to mistrust. The American Medical Association (AMA) lent support to physicians on the issue by stating that patients “do not have the right to demand treatments contrary to medical judgment.”

• Palliative sedation, which “may be considered for terminally ill patients when clinical symptoms are unresponsive to aggressive, symptom- specific treatments,” though clinicians should ensure that “the patient or healthcare proxy have given informed consent for sedation to unconsciousness.”

• Physician-assisted suicide, where a patient intentionally ends his or her own life with help from a physician in the form of information, means, or participation in the terminal act. The American College of Physicians maintains that physicians should “seek to eliminate or alleviate medical conditions that cause suffering at end-of-life” and that physicians should “remain present to ‘suffer with’ the patient in compassion and enlist support of clergy, social workers, and family” when there are no therapeutic options.