The use of complementary and alternative medicine (CAM) has become increasingly popular over recent years. CAM therapies are defined by the National Center for Complementary and Alternative Medicine (NCCAM) as a group of diverse medical and health care systems, practices, and products not presently considered to be part of conventional medicine.1 Biologically based CAM (BB-CAM) includes herbal products, nutraceuticals, and nutritional supplements.2 Data obtained from the 2007 National Center for Health Statistics (NCHS) National Health Interview Survey (NHIS) revealed the following:
- Nearly 40% of the population over age 18 in the United States used some form of CAM therapy in the 12 months prior to the survey (Figure 1)1
- Women (43%) were more likely than men (34%) to use CAM1
- Fish oil (omega-3) and glucosamine were the top 2 natural remedies commonly used (Figure 2)1
- Approximately $34 billion was spent on CAM therapies and visits to CAM practitioners by the US public in 20072
- Out-of-pocket expenditures in 2007 for nonvitamin, nonmineral, natural products, which includes BB-CAM, was approximately $15 billion2
- CAM practice was highest in the American Indian/Alaskan Native population, women, and individuals with higher education levels1
CAM Use and Cancer
Cancer patients were found to have a rate of CAM use higher than that in the general population.3 Lee et al4 studied 373 older cancer survivors (12%) who were surveyed in the 2005-2006 National Social Life, Health, and Aging Project (N = 3005). The participants had a median age of 71 years and had survived a mean of 12 years (range 0-56 years) since diagnosis. The researchers reported that
- 62% of cancer survivors in the study used BB-CAM
- More than half (54%) used nutritional products, 24% used herbals, and 15% used nutraceuticals4
In a study conducted by the Mayo Clinic examining the use of CAM in patients enrolled in phase 1 chemotherapy trials, approximately 88% of patients reported the use of one form of CAM.5 In a European study assessing the prevalence of CAM therapy use by adult oncology patients, herbal remedies (including vitamins and minerals) were most commonly used.6 In a pilot, multidose, placebo-controlled evaluation of American ginseng to reduce cancer-related fatigue, Barton et al reported that American ginseng may decrease fatigue symptoms in cancer survivors. There were no statistically significant differences in any grade of toxicity between the active and placebo arms.7
The use of BB-CAM by patients with cancer raises many challenges for providers. These products are not regulated by the US Food and Drug Administration (FDA), and therefore quality, safety, and efficacy data are lacking. Published proceedings of a joint American Society of Clinical Oncology (ASCO) and American Cancer Society (ACS) symposium on CAM noted that oncologists need to be aware of CAM therapies used by patients and have a basic understanding of the potential toxicities and drug interactions of these agents.8 Herbal remedies may interact with anticancer drugs, possibly increasing or decreasing their effects, causing possible toxicities or decreased efficacy of antineoplastic agents. There may be altered pharmacokinetics, including absorption, distribution, metabolism, and excretion, if an herb is given with anticancer agents.9 Drug interactions may be related to changes in metabolism related to the altered expression or function of the cytochrome P450 (CYP) isoenzymes. In particular, the enzyme CYP3A4 is primarily responsible for the oxidation of a number of chemotherapy agents. Elevation or suppression of CYP activity may alter plasma concentrations, leading to decreased therapeutic effect or increased toxicity of agents.9
Several studies report that patients do not discuss use of CAM therapies with their physicians.4,10,11 Reasons for nonreporting include the beliefs that CAM therapies have no effect on traditional medicine and that CAM therapies are relatively benign, and fear that the health care provider will order the patient to stop using CAM therapies. Physicians must have an open dialogue with patients regarding the use of herbal supplements, using a patient-centered approach.10,12 Crucial strategies to approaching herbal supplement use with patients should include a discussion regarding current knowledge of side effects, drug-herb interactions, and uses based on scientific evidence.12 Table 1 contains information on common BB-CAM products. The goal of this approach is to provide information to enable the patient to make choices. Cancer patients considering the use of CAM therapy should be encouraged to discuss it with their health care providers.12 NCCAM is currently sponsoring a number of clinical trials to evaluate CAM use in cancer.13
Implications for Nursing Practice
It is imperative that oncology nurses discuss the use of BB-CAM with patients at regular intervals. Strategies include
- Asking patients about their use of herbals, nutraceuticals, and nutritional supplements
- Informing them of safety, efficacy, and possible interactions with cancer therapies
Increased attention to potential interactions may decrease the incidence of toxicities and/or decreased efficacy in the oncology setting. Randomized controlled clinical studies are needed to evaluate efficacy of BB-CAM and possible interactions with cytotoxic agents. Until such studies are completed and evidence-based guidelines are published, the safest approach for patients undergoing active treatment for cancer would be to avoid the use of BB-CAM during treatment. Less clear are recommendations for counseling cancer survivors in the use of BB-CAM after completion of therapy. Oncology nurses play a pivotal role across multiple settings in recognizing and communicating information regarding the potential for herb–cytotoxic agent interactions.
Figure 1. CAM Use by US Adults and Children
From National Center for Complementary and Alternative Medicine. http://nccam.nih.gov/news/camstats/2007
Figure 2. 10 Most Common Natural Products Among Adults
From National Center for Complementary and Alternative Medicine. http://nccam.nih.gov/news/camstats/2007
Table 1. Medicinal Herbs and Their Uses (download pdf file)
Based on information from Medline Plus, National Library of Medicine.14
World Health Organization (WHO). WHO guidelines on safety monitoring of herbal medicines
in pharmacovigilance systems. http://apps.who.int/medicinedocs/index/assoc/s7148e/s7148e.pdf Accessed January 8, 2011.
- Lee CO. Herbs and cytotoxic drugs: recognizing and communicating potentially relevant interactions. Clin J Oncol Nurs. 2005;9:481-487. doi: 10-1188/05.CJON.481-487
- Montbrand MJ. Herbs or natural products that may cause cancer and harm. Part four of a four-part series [Online Exclusive]. Oncol Nurs Forum. 2005;32:E20-E29. doi: 10-1188/05.ONF.E20-E29
- Decker GM. The ten cardinal rules of herb use. Clin J Oncol Nurs. 2006;10:279. doi: 10.1188/06.CJON.279
The National Center for Complementary and Alternative Medicine (NCCAM) Resources
- Barnes PM, Bloom B, Nahin RL. Complementary and alternative medicine use among adults and children: United States, 2007. National Health Statistics Reports; No 12. Hyattsville, MD: National Center for Health Statistics. 2008. http://nccam.nih.gov/news/camsurvey_fs1.htm. Accessed March 15, 2010.
- Nahin RL, Barnes PM, Stussman BJ, Bloom B. Costs of complementary and alternative medicine (CAM) and frequency of visits to CAM practitioners: United States, 2007. http://nccam.nih.gov/news/camstats/costs/nhsrn18.pdf. Accessed March 18, 2010.
- Mao JJ, Farrar JT, Xie SX, et al. Use of complementary and alternative medicine and prayer among a national sample of cancer survivors compared to other populations without cancer. Complement Ther Med. 2007;15:21-29.
- Lee RT, Qato D, Curlin F, et al. Older cancer survivors’ use of biologically based complementary and alternative medicine (CAM): a national, population-based study in the United States [abstract]. J Clin Oncol. 2008;26(15 suppl). Abstract 9508. http://www.asco.org/ASCOv2/Meetings/Abstracts?&vmview=abst_detail_view&confID=55&abstractID=33516. Accessed March 16, 2010.
- Dy GK, Bekele L, Hanson LJ, et al. Complementary and alternative medicine use by patients enrolled onto phase I clinical trials. J Clin Oncol. 2004;22:4810-4815.
- Deng G, Cassileth B. To what extent do cancer patients use complementary and alternative medicine? Nat Clin Pract Oncol. 2005;2:496-497.
- Barton DL, Soori GS, Bauer B, et al. A pilot, multi-dose, placebo-controlled evaluation of American ginseng (panax quinquefolius) to improve cancer-related fatigue: NCCTG trial N03CA [abstract]. J Clin Oncol. 2007;25(25 suppl). Abstract 9001. http://meeting.ascopubs.org/cgi/content/abstract/25/18_suppl/9001. Accessed March 18, 2010.
- Markman M. Safety issues in using complementary and alternative medicine. J Clin Oncol. 2002;20(18 suppl):39s-41s.
- Lee CO. Herbs and cytotoxic drugs: recognizing and communicating potentially relevant interactions. Clin J Oncol Nurs. 2005;9:481-487. doi: 10.1188/05.CJON.481-487.
- Frenkel M, Ben-Arye E, Baldwin CD, Sierpina V. Approach to communicating with patients about the use of nutritional supplements in cancer care. South Med J. 2005;98:289-294.
- Richardson MA, Straus SE. Complementary and alternative medicine: opportunities and challenges for cancer management and research. Semin Oncol. 2002;29:531-545.
- Smith AM. Opening the dialogue: herbal supplementation and chemotherapy. Clin J Oncol Nurs. 2005; 9:447-450. doi: 10.1188/05.CJON.447-450.
- National Center for Complementary and Alternative Medicine. National Institutes of Health. NCCAM Clinical Trials. http://nccam.nih.gov/research/clinicaltrials/. Accessed March 19, 2010.
- Medline Plus, National Library of Medicine, National Institutes of Health. All Herbs and Supplements. http://www.nlm.nih.gov/medlineplus/druginfo/herb_All.html. Accessed March 16, 2010.
biologically based CAM—herbal products, nutraceuticals, and nutritional supplements. These products are not regulated by the US Food and Drug Administration
complementary medicine—used together with conventional medicine; alternative medicine—used in place of conventional medicine. When CAM is used in combination with conventional medicine it is often termed integrative medicine
cytochrome P450—human cytochrome P450, also known as CYP and primarily found in the cells of the liver and small intestines; understanding the reactions of a drug depends on knowing the role of CYP
CYP34A—specific genetic code of the P450 superfamily. Of all the CYPs in the liver, 34A is in the largest quantity; in the intestine, it plays an important role in the metabolism of certain drugs
efficacy—effectiveness or ability of a drug to control or cure an illness: the maximum ability of a drug or treatment to produce a result regardless of dosage. A drug passes efficacy trials if it is effective at the dose tested and against the illness for which it was prescribed. In the procedure mandated by the FDA, phase 2 clinical trials gauge efficacy and phase 3 trials confirm it
nutraceutical—foods or extracts claimed to have a medicinal effect on human health
pharmacokinetics—of or relating to the study of the bodily absorption, distribution, metabolism, and excretion of drugs. It is often summarily stated that pharmacokinetics is the study of what the body does to the drug