Over eighty percent of breast cancer patients in the United States use complementary therapies following a breast cancer diagnosis, but there has been little science-based guidance to inform clinicians and patients about their safety and effectiveness. In newly published guidelines from the Society for Integrative Oncology, researchers at Columbia University's Mailman School of Public Health and the Herbert Irving Comprehensive Cancer Center with colleagues at MD Anderson Cancer Center, University of Michigan, Memorial Sloan Kettering, and other institutions in the U.S. and Canada, analyzed which integrative treatments appear to be most effective and safe for patients. They evaluated more than 80 different therapies.
Meditation, yoga, and relaxation with imagery were found to have the strongest evidence supporting their use. They received an "A" grade and are recommended for routine use for anxiety and other mood disorders common to breast cancer patients. The same practices received a "B" grade for reducing stress, depression, and fatigue, but are also endorsed for most breast cancer patients. Acupuncture received a "B" grade for controlling chemotherapy induced nausea and vomiting and can be recommended to most patients. More than 30 interventions, including some natural products and acupuncture for other conditions, had weaker evidence of benefit due to either small study sizes or conflicting study results, and received a "C" grade. Seven other therapies were deemed unlikely to provide any benefit and are not recommended. One therapy was found to be harmful: acetyl-l-carnitine, which is marketed to prevent chemotherapy-related neuropathy, and actually increased risk for the condition.
Results appear online in the Journal of the National Cancer Institute Monographs.
To conduct their analysis, the researchers used a set of nine biomedical publication databases to review randomized controlled clinical trials conducted from 1990 through 2013 among breast cancer patients that tested complementary therapies together with standard cancer care - defined as surgery, chemotherapy, radiation therapy, and hormonal therapy. Based on a set of guidelines developed by the Institute of Medicine, the researchers considered the magnitude and type of benefit and harm along with trial quality and size. Of 4,900 research articles reviewed, 203 met the criteria for the final analysis. Recommendations were organized by clinical outcome and graded using the U.S. Preventive Services Task Force grading system.
"Most breast cancer patients have experimented with integrative therapies to manage symptoms and improve quality of life. But of the dozens of products and practices marketed to patients, we found evidence that only a handful currently have a strong evidence base," said Heather Greenlee, ND, PhD, assistant professor of Epidemiology at Columbia's Mailman School of Public Health and president of the Society for Integrative Oncology.
A number of interventions did not have sufficient evidence to support specific recommendations. "This does not mean that they don't work, this means that we don't yet know if they work, in what form, or what dose is the most effective. The vast majority of therapies require further investigation through well-designed controlled clinical trials," said Dr. Greenlee.
"A challenge in assessing the safety and effectiveness of complementary therapies was the lack of standardization of interventions across trials using similar therapeutic approaches," said Debu Tripathy, MD, professor and chair of breast medical oncology at MD Anderson Cancer Center. "In addition, some integrative therapies are applied in a variety of settings - early vs. advanced stages of disease and a spectrum of symptom severity - such that the clinical criteria for using some therapies may not be straightforward." However, the researchers also found that many of the complementary therapies were low risk, and the lack of means to measure them may not greatly influence their clinical application.
"These guidelines provide an important tool for breast cancer patients and their clinicians as they make decisions on what integrative therapies to use and not use. The guidelines clearly demonstrate that clinicians and patients should adopt shared decision-making approaches when assessing the risk-benefit ratio for each therapy. It is important to personalize the recommendations based upon patients' clinical characteristics and values. What's right for one patient, may be wrong for another," said Dr. Greenlee.