Breakthrough Pain in Cancer Patients Is Severe, Unpredictable

LOS ANGELES--Cancer patients with breakthrough pain episodes reportmore severe pain than those who do not have breakthrough pain,a study from Memorial Sloan-Kettering Cancer Center has shown.

"Episodes of breakthrough pain must be addressed since theycan result in increased pain intensity and psychological distress,"Russell K. Portenoy, MD, said at the American Pain Society meeting.He defined breakthrough pain as episodes of excruciating painsuperimposed on otherwise well-controlled pain.

In Dr. Portenoy's study of more than 150 patients with cancer-relatedpain at Memorial Sloan-Kettering, those patients with breakthroughpain reported significantly greater baseline pain, and the severityof their pain was greater than that experienced by patients whodid not have episodes of breakthrough pain.

More than 80% of the patients with breakthrough pain reportedpain that was present either constantly or frequently, comparedwith just over 50% of patients without breakthrough pain who reportedpain present at the same level.

Those patients with breakthrough pain used more supplemental painmedication than did patients without breakthrough pain, althoughthere was no difference in their round-the-clock opioid dosage.

Compared with patients who did not report breakthrough pain, thepatients with breakthrough pain showed significant impairmentsin psychosocial functioning as a result of the pain; increasedinterference in activity, mood, movement, and sleep; and moreimpairment in social relationships, occupational functioning,and general enjoyment of life.

They also had significantly more symptoms of both depression andanxiety, and significantly more negative thoughts about theirpain in general and, specifically, about themselves and theirability to function effectively in a psychosocial context.

'The Most Poignant Finding'

"One of the most striking and poignant findings was the unpredictabilityof the episodes of breakthrough pain," Dr. Portenoy said.More than three fourths of the patients with breakthrough painstated that they were never able to predict when they were goingto have an episode. "The psychological impact of being sounable to control pain is devastating for patients," he commented.

Although, in the past 10 years, there has been a growing recognitionof the problem of pain in the oncology setting and efforts toimprove pain management, the phenomenon of breakthrough pain continuesto be under-recognized.

"The finding that these patients are more psychologicallydistressed underscores the need of addressing this pain problemmore aggressively," he said.

To date, no scientific studies have established the benefits ofone treatment for breakthrough pain over another. Anecdotally,Dr. Portenoy said, the most common therapy is the use of supplementalopioids administered on an "as needed" basis. "Opioidsused in this fashion are called rescue doses," he said.

A variety of other techniques might be employed when the sourceof the breakthrough pain can be determined. For example, if thebreakthrough pain is found to be related to cough, the use ofanti-tussives may be a way of reducing the frequency of pain episodes.

If breakthrough pain is related to dysmotility of the bowel, itmay be possible to reduce episodes by use of drugs that alterbowel motility.

"In some cases, the only way to reduce breakthrough painby drugs is by doing an invasive procedure targeted specificallyat the breakthrough pain," Dr. Portenoy said. For example,a procedure that blocks the nerves coming from the painful areamay be the only way to reduce intense breakthrough pain stemmingfrom movement.

"The take home message is that patients with cancer painare a heterogeneous population, and that to best manage this pain,a detailed assessment of various aspects of the pain experienceis important," Dr. Portenoy said. He stressed that the assessmentshould include questions about the impact of pain on psychosocialfunctioning.

Dr. Payne is a Barbara White Fishman Psychiatry Fellow, PsychiatryService, Memorial Sloan-Kettering Cancer Center, New York.