Pump implant cuts pain, new research shows

Cancer survival times longer with pump

Delivering pain drugs directly into the spinal fluid with a small pump implanted under the skin can give cancer patients better pain relief with fewer side effects than other common methods, according to a new research study.

"The purpose of this trial was to see if the pump, added to the best pain management we could give, would improve pain control and decrease drug side effects, and it did," said Thomas J. Smith, MD, professor and chair of the hematology and oncology department at Virginia Commonwealth University in Richmond. Smith and colleagues published their report in the Journal of Clinical Oncology (19:4040-4049).

The researchers looked at 200 patients who had unrelieved pain when they began the study. As part of the study, patients underwent comprehensive medical management (CMM) under their oncologists and pain experts. Established pain guidelines were used, Smith said.

About half of the patients in the study were given an implanted pump in their abdomen that regularly sent small amounts of pain drugs into their spinal fluid. After four weeks, patients were asked to rate their pain on a scale of one to 10, while physicians noted any toxic effects. About 85% of patients using CMM plus the pump got pain relief, compared with about 71% using only CMM. CMM alone cut pain intensity by about 39%, compared to about 52% with the pump added.

More people on the pump plus CMM had pain levels low enough to allow them to resume normal daily activities, compared to those on CMM alone. Side effects of the pain medications, such as fatigue and constipation, fell by about 50% in the pump plus CMM group, but only by about 17% with CMM alone.

Survival was lengthened as a result of pump use. Smith attributed the increased survival time to lower pain and improved quality of life, including greater mobility and appetite.

Over two-thirds of patients with advanced cancer have pain, and up to 15% have pain that is not relieved by usual methods, said Smith.

Many refuse pain drugs to avoid side effects such as sleepiness, fatigue, depression, constipation, loss of sexual function, loss of appetite, and nausea that can come with oral or IV-needle doses high enough to stop their pain, noted Smith.