Study Reveals Benefits of Drug Pump for Cancer Pain

According to the results of a landmark study published in a recent issue of the Journal of Clinical Oncology (20:4040-4049, 2002), how painkillers are delivered can make a major difference in patient outcome. The trial, supported by Medtronics Inc, was the first to compare routes of administering opioids for intractable cancer pain. Results showed that opioids delivered via an implantable infusion system provided better relief from moderate to severe cancer pain with smaller doses and significantly fewer side effects. Intrathecal infusion also improved the quality of life of patients and caregivers. The data suggest, moreover, that the programmable drug pump may have helped patients live longer—by about 2 months, on average. This finding requires further study.

Benefits of Direct Deposit

"Opioids such as morphine are extremely effective for treating severepain," said cancer pain specialist Peter S. Staats, MD, associate professorof anesthesiology and critical care medicine at Johns Hopkins University Schoolof Medicine in Baltimore, and one of the study investigators."Unfortunately, in high doses they can also cause sedation, cloudedthinking, constipation, and fatigue—a constellation of side effects that leadmany physicians to underprescribe these drugs and many patients to underusethem. With this study, we’ve shown that by altering how we deliver themedications, we can provide better pain relief, minimize the side effects, andperhaps even help patients to live longer."

According to the American Cancer Society, about one-third of cancer patientsand two-thirds of patients with advanced or metastatic disease experience pain,but up to 15% fail to get relief from oral opioids. For a subset of thesepatients—approximately 50,000—intrathecal therapy with a programmable drugpump represents a viable option.

"As an oncologist, I’ve seen firsthand how a patient’s pain canhamper our efforts to treat the cancer itself and adversely affect the entirefamily," said Thomas J. Smith, MD, chairman of hematology and oncology atVirginia Commonwealth University’s Massey Cancer Center in Richmond, a studyinvestigator, and the lead author of the manuscript. "By using the pump, wecan deliver medication directly into the patient’s spinal fluid, where smalldoses can have a big impact on pain. Put simply, less medication means fewerside effects, which makes life better not only for the patient but for thepatient’s family, too. And with the pain under control, we can focus ontreating the cancer."

Study Data

Worldwide, 202 patients from 21 medical centers participated in the study.The primary end points were pain control and change of drug toxicity.Researchers defined clinical success as a greater than or equal to 20% reductionin visual analog scale (VAS) pain scores or equal pain scores with a greaterthan or equal to 20% reduction in toxicity.

At 4 weeks, the pain scores for pump patients fell 52%, compared with a 39%drop in patients who received only conventional therapy (P = .055). Useof the pump reduced composite drug-related toxicity scores by 50% compared witha 17% decrease in the conventional group (P = .004). Importantly, theresearchers found statistically significant reductions in fatigue and sedationin pump patients compared with patients receiving conventional therapy alone (P< .05). In addition, 54% of patients in the pump group were alive after 6months of treatment, compared with 37% in the conventional therapy group (P =.06).

During the trial, complications with the infusion system were similar tothose seen in typical clinical use. Because the drug pump is surgically placed,surgical complications, such as infections, may occur. The catheter could bedislodged or blocked, or in rare cases, the pump could stop working.