Implantable drug pump offers hope to people with cancer pain

Preliminary results from an ongoing study suggest a solution to cancer pain that conventional treatment alone cannot control, a predicament facing thousands of people with cancer and the oncologists responsible for treating them.

Presented here at the annual meeting of the American Society of Clinical Oncology (ASCO), interim data from 22 patients, a small subset of the approximately 200 patients expected to participate in the global 21-center clinical trial, indicate that infusing small and precisely controlled doses of morphine directly into the spinal fluid can relieve cancer pain when conventional medical management (CMM) by itself has failed to provide adequate relief. The treatment, which uses Medtronic's SynchroMed® EL Infusion System, is called intrathecal pain therapy.

"As oncologists, we do our best to treat our patients' cancer and their pain with the tools and techniques we know, but thousands of cancer patients still live and die in pain," said Thomas Smith, M.D., chief of hematology and oncology at Virginia Commonwealth University's Massey Cancer Center in Richmond and one of the study's chairmen. "Early results from this research should encourage more oncologists to consider using implantable programmable drug pumps for intrathecal infusion of morphine to treat patients who continue to experience intractable pain even after traditional pain management."

Data for the special group of 22 study patients, who were randomly assigned to receive CMM but subsequently failed traditional pain management options, show that the addition of intrathecal pain therapy improved pain scores by more than 15 percent and reduced side-effect scores by more than 47 percent after one month. Treatment with intrathecal pain therapy also sustained these patients' quality of life at a point in disease progression when quality of life usually declines.

About the Study

This ongoing study is sponsored by Medtronic (NYSE: MDT). Patients, who are prospectively randomized to receive either CMM or intrathecal pain therapy, rate their pain upon enrolling and during nine subsequent follow-up visits over a six-month period. Baseline pain scores, reported by the 150 patients in both study groups for whom data was available for the ASCO meeting, averaged 7.4 on a 0-10 scale. These patients reported high pain scores despite doses of opioids that also caused intolerable side effects, which in some cases required additional medical or surgical intervention to treat.

The researchers pointed out that people with cancer pain do not suffer alone. Early findings from the study demonstrate that the negative impact of cancer pain and medication side effects extend to patients' caregivers, who were mostly family members.

Final study results for at least 200 patients are expected to be available early in 2002, after the researchers complete their analysis.

Responsible for one in four deaths in the United States, cancer will kill more than 550,000 Americans this year alone, according to the American Cancer Society. For millions of people living with cancer (or caring for a loved one who is), killing the pain becomes a top priority.

That is not always possible with painkillers, however. Oral medications have been shown in previously published research to be ineffective for 10 percent of cancer pain patients. Many cancers, such as lung, breast and prostate cancer, can cause pain so severe that it cannot be controlled with conventional medical management, which almost always includes powerful narcotics, such as morphine or oxycodone, taken by mouth in escalating doses. For patients who receive some relief from pain pills, oral medications often create side effects, including nausea, vomiting, sedation and constipation that detract from an already poor and declining quality of life. In these cases, patients can't tolerate the dose required to relieve their pain.

"Most people with cancer pain who receive morphine through an implantable programmable drug pump not only find relief from their pain, but also experience far fewer and much milder side effects from the medication," explained Peter Staats, M.D., chief of pain medicine at Johns Hopkins University Medical Center in Baltimore and the study's other chairman. "That usually makes life better for the patient and their family."

Pain Management

Government agencies, physician associations and patient advocacy groups have made effective pain management a national goal. New standards from the Joint Commission on Accreditation of Health Care Organizations (JAHCO), a national standards-setting and accrediting body in health care, mandate that physicians and other healthcare professionals assess and treat pain separately from the disease or condition that's causing it. "Effective pain management is appropriate for all patients, not just for dying patients," the standards state. JAHCO recently dubbed pain "the fifth vital sign."

Still, pain remains undertreated, medical experts say -- in part because it's difficult to assess and to treat. Another reason cited is that many patients suffer in silence for fear of becoming addicted to painkillers or from aversion to being overly sedated. That's especially true among people with cancer.

"As my cancer progressed, so did my pain, but I never told my doctor because I didn't think there was much that could be done about it," recalled Peggy Carson, a San Antonio woman with bone cancer affecting her spine who began receiving morphine through the Medtronic SynchroMed® EL Infusion System in 1998. "I figured the pain was something I just had to live with."

Medtronic's implantable programmable drug pump dispelled that myth for Carson. "After starting intrathecal pain therapy, I got home and was able to be outside planting flowers -- an activity I love but hadn't been able to do for ages because I had so much back pain. It's truly a blessing not to have the constant, intense pain. This therapy makes me feel like I'm part of some progress being made to help cancer patients maintain quality of life."

With intrathecal pain therapy, morphine is delivered directly to the intrathecal space, the area surrounding the spinal cord. The medication is administered by a programmable drug pump and catheter that are surgically placed underneath the skin of the abdomen. The surgical procedure, which can be performed on an outpatient basis, typically takes about an hour. Since 1991, more than 45,000 people worldwide have received intrathecal pain therapy with a Medtronic drug pump.

Since the medication is delivered directly to the pain pathway, small doses can be very effective with intrathecal infusion. Site-specific drug delivery may also help to minimize side effects and limit addiction potential. The same therapy is used to treat nonmalignant pain, such as low back and complex regional pain, when oral medications no longer provide adequate relief with acceptable side effects.

About Medtronic

Medtronic, headquartered in Minneapolis, is the world's leading medical technology company, providing lifelong solutions for people with chronic disease. Its Internet address is www.medtronic.com.

Any statements made about Medtronic's anticipated financial results and regulatory approvals are forward-looking statements subject to risks and uncertainties such as those described in the company's Annual Report and on Form 10-K for the year ended April 30, 2001. Actual results may differ materially from anticipated results.

Source: Medtronic

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