CAM Use May Delay Chemotherapy in Breast Cancer

Roxanne Nelson, BSN, RN

May 13, 2016

Breast cancer patients who used complementary and alternative medicine (CAM) were less likely to initiate recommended chemotherapy than nonusers, according to results from a study published online May 12 in JAMA Oncology.

The CAM therapies included dietary supplements (vitamins, minerals, herbs, and botanicals), other natural products, and mind–body self-practice or practitioner-based practice.

Of the women for whom chemotherapy was indicated, current use of dietary supplements (adjusted odds ratio [OR], 0.16) was associated with decreased likelihood of chemotherapy initiation, as was a higher score on the CAM index (adjusted OR, 0.64), report Heather Greenlee, ND, PhD, from the Mailman School of Public Health at Columbia University in New York City, and her colleagues.

The use of mind–body practices, however, was not associated with a decrease in chemotherapy initiation.

Of the 685 study participants, 598 (87%) reported CAM use at baseline, most commonly dietary supplements and mind–body practices.

The median number of CAM therapies used was two, but 261 women (38%) reported that they were using at least three types.

Chemotherapy was indicated for 306 women, according to National Comprehensive Cancer Network guidelines, and 272 of these (89%) did begin treatment. Chemotherapy was discretionary for 379 women, and only 135 (36%) of these women began treatment.

It is not clear whether the association between CAM use and the noninitiation of chemotherapy reflects long-standing decision-making patterns among study participants, the researchers report.

"Though the majority of women with clinically indicated chemotherapy initiated treatment, 34 of 306 (11%) did not," they write. "A cautious interpretation of results may suggest to oncologists that it is beneficial to ascertain CAM use among their patients, especially dietary supplement use, and to consider CAM use as a potential marker of patients at risk of not initiating clinically indicated chemotherapy."

Have the Conversation

These results, along with those from previous studies, emphasize the need to improve our understanding of the decision-making process of cancer patients, as far as their choice of conventional or alternative treatments, Robert Zachariae, DMSc, from Aarhus University Hospital in Denmark, writes in an accompanying editorial.

The fact that CAM use might be associated with the noninitiation of potentially life-saving adjuvant treatment highlights the "urgent need to train oncologists to enhance their ability to improve patient disclosure of CAM," according to Dr Zachariae.

"This is part of a larger issue," he told Medscape Medical News. "Asking about CAM should be a part of a more general patient-centered approach —not only about symptoms but also about other psychological and social issues."

He pointed out that asking the patient the general question, 'What things do you do yourself to try to improve your health,' and then probing further about specific issues, such as CAM, could be a general approach.

"Other important questions of relevance for adherence are those addressing the patients' beliefs about their disease, its treatment, and so on," Dr Zachariae said. "Whether the patients will disclose these aspects or not depends on general communicative skills and a basic attitude of the physician, such as showing that he/she is genuinely interested in what the patient thinks, believes, and does and considers this important."

Another issue is that many physicians know relatively little about the many individual CAMs, but he emphasized that this is not limited to CAM. "This also applies to traditional treatments," he explained. "Building databases on the current evidence, or lack of, on effects, interactions, etc., that physicians could access would be helpful here. "

Less Likely to Initiate Chemo

The use of CAM is very common in cancer patients. One study showed that it is used by almost half of all cancer patients, as reported by Medscape Medical News. In many cases, CAM is typically used for pain relief and to control the adverse effects of disease or treatment.

For their study, Dr Greenlee's team assessed participants from the Breast Cancer Quality of Care Study (BQUAL), a prospective cohort study that is examining the demographic, behavioral, biomedical, and psychosocial predictors of treatment initiation and adherence to adjuvant therapy in women with early-stage breast cancer.

The women were treated at the Columbia University Medical Center, Kaiser Permanente Northern California, and Henry Ford Health System from 2006 to 2010.

All the women were younger than 70 years (mean age, 59 years), had nonmetastatic invasive breast cancer, were followed for up to 12 months, and underwent a baseline interview to assess the current use of CAM.

The researchers sought to determine whether CAM use was associated with a decrease in the initiation of chemotherapy for breast cancer.

The women who did not initiate chemotherapy were more likely to report using dietary supplements than those who did initiate chemotherapy (88% vs 62%; P = .002).

Noninitiators of chemotherapy were more likely than initiators to use vitamins and/or minerals (71% vs 28%; P < .001).

And women who used more CAM therapies, as indicated by a higher CAM index score, were significantly less likely to initiate chemotherapy (P = .001).

But when chemotherapy was discretionary, there was no association between CAM use and chemotherapy initiation.

This study was supported by grants from the National Cancer Institute and a Department of Defense Breast Cancer Center of Excellence Award. Coauthor Lawrence Kushi, ScD, from Kaiser Permanente Northern California in Oakland, is on the board of directors of the Kushi Foundation, a nonprofit organization that promotes educational activities regarding macrobiotics. Dr Zachariae has disclosed no relevant financial relationships.

JAMA Oncol. Published online May 12, 2016. Abstract


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