What Patients Don't Know Might Hurt Them

Andrew L. Pecora, MD

Editor-in-Chief Chief Innovations Officer, Professor, and Vice President of Cancer Services John Theurer Cancer Center at Hackensack University Medical Center

Complementary! Sounds good, how could it hurt? When applied in cancer therapy, however, what sounds good may not always be good for patients. More than 65% of cancer survivors report using some form of “complementary“ or “alternative” medicine while receiving standard therapy, but strikingly, less than half of these patients inform their physicians even when asked. If something is considered complementary, why hide it from your physician? These questions are now facing significant scrutiny because what would seem to be an obvious—almost commonsense—notion of benefit has been found to be harmful in some circumstances.

For example, it was once believed that beta carotene was capable of reducing the risk of lung cancer due to its antiproliferative properties.¹ It turned out that people receiving beta carotene, as shown in several studies, had an average 20% increased incidence of developing lung cancer. Another example is vitamin E, which was once thought to help prevent many maladies, including cardiovascular disease, autoimmune disorders, and cancer.² Here again the data did not bear out any benefit to patients. In fact, one study showed that patients who took vitamin E had a 17% increased risk of developing prostate cancer.²

Early research done in animals found that vitamin A- and vitamin E-deficient mice experienced less brain tumor progression than control animals that were not vitamin-deficient, possibly due to suppression of apoptosis by antioxidants.³ Other studies indicate that complementary medicines may reduce the side effects of chemotherapy and improve survival.^4,5 In light of the conflicting studies and anecdotal evidence, most professionals agree that the data are just not clear enough to recommend complementary medicines, and yet most patients take them anyway. Why?

Archeologists have found that from the beginning of humanity, man has demonstrated a need to understand and to control his environment. When something is a mystery, people will find an answer that brings them comfort and a sense of control, like early man burying tools with the remains of their loved ones for the afterlife. Early medicine is filled with remedies for a host of illnesses, including bloodletting and burr holes to let out the bad humors. These “remedies” were based on anecdotes and good intentions, but in the end were harmful to patients.

More than 65% of cancer survivors report using some form of “complementary“ or “alternative” medicine while receiving standard therapy, but strikingly, less than half of these patients inform their physicians even when asked.

This need to understand and control our health and our bodies has not changed or diminished. However, what has changed is our understanding of the causes of cancer and the ability to rationally target therapies. Well-designed clinical trials and molecular pathway elucidation should provide patients with a better insight into the causes and proper treatments of cancer. As oncologists become better equipped with the diagnostic tools and targeted therapies to treat cancer and personalize medicine, it is our hope that patients will feel less inclined to bring along “extra tools” on their journey.

References

1. Omenn GS, Goodman GE, Thornquist MD, et al. Risk factors for lung cancer and for intervention effects in CARET, the Beta-Carotene and Retinol Efficacy Trial. J Natl Cancer Inst. 1996;88(21):1550-1559.
2. Klein EA, Thompson IM Jr, Tangen CM, et al. Vitamin E and the risk of prostate cancer: the Selenium and Vitamin E Cancer Prevention Trial (SELECT). JAMA. 2011;306(14):1549-1556.
3. Albright CD, Salganik RI, Van Dyke T. Dietary depletion of vitamin E and vitamin A inhibits mammary tumor growth and metastasis in transgenic mice. J Nutr. 2004;134(5):1139-1144.
4. Lawenda BD, Kelly KM, Ladas EJ, Sagar SM, Vickers A, Blumberg JB. Should supplemental antioxidant administration be avoided during chemotherapy and radiation therapy?. J Natl Cancer Inst. 2008;100(11): 773—783.
5. Block KI, Koch AC, Mead MN, Tothy PK, Newman RA, Gyllenhaal C. Impact of antioxidant supplementation on chemotherapeutic toxicity: a systematic review of the evidence from randomized controlled trials. Int J Cancer. 2008;123(6): 1227—1239.