Electroacupuncture May Counter Patients’ Nausea After Chemotherapy
NCI CAM Annual Report-FY10
Many cancers are treated with chemotherapy agents that circulate throughout the body. When the drugs reach organs and tissues not affected by cancer, they can cause adverse side effects. Among the most prevalent and troublesome side effects are nausea and vomiting, though recently a new class of molecules – known as 5HT3 agonists, and used in combination with corticosteroid dexamethasone pills – have been found to help reduce or even prevent these symptoms.
“But those drugs [5HT3 agonists] work effectively only against what we call acute-onset nausea and vomiting,” said Dr. Jiande Chen, Ph.D., professor of Medicine at the University of Texas Medical Branch. “Once you get past the first day, many patients suffer from delayed nausea and vomiting, which is really a different problem altogether, can last for many hours or several days, and is much more difficult to treat.” Patients with advanced cancer can also develop chronic nausea symptoms.
Older patients and others can wear down from the rigors of chemotherapy and many are reluctant to add yet another medication to their treatment regimen, especially if it is supposed to counter symptoms that were caused by medication in the first place. For example, with a drug like cisplatin, “it is not uncommon to find patients choosing to discontinue chemotherapy altogether – even when it is effectively treating their cancer – in order to avoid these debilitating side effects,” explained Dr. Chen.
In China, there is widespread use and acceptance of acupuncture to treat nausea. “It is encouraging to find more and more practitioners and patients in the United States willing to accept this therapy,” he said. Acupuncture relies on the stimulation of very precise points on the body located beneath the skin. Each of these “acupoints” is associated with pain or other symptoms at a specific, usually distant, site in the body. After several thousand years of use, acupuncture practitioners have been able to develop detailed “body maps” for these points. Two of the acupoints that inhibit nausea and vomiting have been found to be PC6 – a few inches above the inside of the wrist – and ST36 – slightly below and behind the knee, Dr. Chen explained. In previous studies, needles inserted at these points and then manually manipulated have produced some results, but they were only partial responses, and worked only against acute vomiting after chemotherapy.
Dr. Chen believes those mixed results were due, not to any limits in acupuncture per se, but rather to how it has been applied. With NCI funding*, Dr. Chen and his colleagues have been testing electroacupuncture (EA), to see if it is even more effective than traditional acupuncture against chemotherapy-induced nausea. Electroacupuncture is a procedure in which pulses of weak electrical current are sent through acupuncture needles into acupuncture points in the skin. Using rats and dogs, their current study is testing the precise location and depth the acupuncture stimulation should be applied; whether to use EA before or after chemotherapy, or both; whether the regimens should be continuous; and also the frequency and intervals of the electric pulses themselves.
The researchers are working on several aspects of EA that would be important in delivering therapy to patients for whom current anti-emetics (drugs to counter nausea and vomiting) are not working. That group potentially includes the majority of patients with delayed or chronic nausea and vomiting.
Dr. Chen believes that a successful series of experiments with the EA approach could have a major impact on treating symptoms that threaten the quality of life of cancer patients. “This EA therapy has no discernible side effects on the patient, and therefore we can give it chronically, as necessary, to respond to symptoms,” he added. Dr. Chen and his colleagues are also testing a system where a small power stimulator is implanted in the abdomen of the experimental animals, with conducting wires leading under the skin to electrodes that have been carefully inserted at the acupoints. The researchers will be able to trigger the EA stimulation by an external transmitter, but ultimately Dr. Chen foresees a time when patients will be able to control a similar system themselves.
*Grant number: 1R21CA149956-01