A Pilot Trial of Scrambler Therapy for Pain Associated With Pancreas Cancer

Pancreas cancer causes pain in 70% of newly diagnosed patients rising to over 80% in advanced cancer patients, and is the most common serious symptom. Pancreas cancer pain is strongly correlated with worsened survival, and relief of pain is correlated with better survival. Pancreas cancer pain is neuropathic in origin and sensation, arising from direct invasion of local tissues. Pancreas cancer pain is relieved by local nerve blocks in about 75% of cases, but the relief is often incomplete, temporary, and the procedure is invasive with some risks. As the cancer grows to involve more nerves, or the nerves regrow, the pain typically comes back. For the 46,420 newly diagnosed pancreas cancer patients and the 39,500 patients who die of it each year, pain is the one constant symptom.

Scrambler Therapy is a novel treatment increasingly supported by clinical experience and multiple trials. The goal of the device is to provide "non-pain" information through the cutaneous nerves to block the effect of pain information. The device is a cutaneous electrical stimulator that creates waveforms simulating 16 different action potentials, then transmits the action potentials via C fibers. The goal is to reset the brain to perceive "non-pain" from areas previously interpreted as painful, similar to spinal cord stimulation. The multiprocessor apparatus directly stimulates the peripheral nerves by the application of surface electrodes on the skin, similar to EKG electrodes, putting the electrodes above and below the site of pain.

Preliminary data on Scrambler therapy in pancreas cancer Scrambler Therapy appears to work on pain based on results from multiple trials. In fact, the first trial was done on patients with abdominal pain from abdominal cancers. In this first trial, 11 cancer patients (3 pancreas, 4 colon, 4 gastric) suffering from drug resistant visceral pain were studied during the patients' first ten treatment sessions. The pain score before the treatment is shown next to the pain score after treatment, for each daily treatment. The electrodes were placed to surround the pain, following the dermatomes, as shown in Figure 2. The active (yellow) electrodes are always paired across the pain with the passive (black) electrode. Pain was quickly and markedly reduced and maintained until death. As then inventor wrote, "During the applications, all the patients reported a very rapid (in the order of a few seconds) disappearance of the perception of pain. All patients responded fully to the protocol and none reported undesirable side effects. Compliance was excellent." Nine of 11 stopped pain drugs within the first 5 applications. "During the reference period, nine out of eleven patients (81.8%) are seen to have stopped requesting painkillers between the second and the fifth treatment session. The remaining two patients (18.2%) considerably reduced the dosage and undertook mild therapy."

To be blunt, no one really believed these results. The magnitude of pain relief was large, with a simple machine using non-invasive therapy. To this day, the trial has not been replicated. But over the next decade, more and more evidence about Scrambler Therapy emerged from different investigators that led the investigators to believe that there was a signal worth exploring for relief in pancreas cancer. In the second trial, 226 patients with neuropathic pain including failed back surgery, brachial plexus neuropathy, and others were treated. Over 80% of patients responded with > 50% pain relief, 10% responded with pain relief from 25% to 49%, and only 10% had no response (P<0.0001). Based on these results the FDA approved Scrambler Therapy for cancer pain treatment February 25, 2009. The investigators have recently compiled the published reports of Scrambler Therapy for a review.

4. Study Procedures