CAM Supplement Users Less Likely To Initiate Breast Cancer Chemotherapy

Breast cancer patient use of complementary and alternative medicine supplements may flag chemotherapy nonuse

  • Date: 15 May 2016
  • Author: By Lynda Williams, Senior medwireNews Reporter
  • Topic: Breast Cancer

medwireNews: Breast Cancer Quality of Care (BQUAL) Study results suggest that women may be less likely to begin a recommended course of chemotherapy if they use complementary or alternative medicine (CAM) dietary supplements.

“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”, write Heather Greenlee, from Columbia University in New York, USA, and co-investigators in JAMA Oncology.

“This information can prompt further discussions between physicians and patients on chemotherapy expectations, with the common goal of addressing concerns and enhancing shared and informed decision making about clinically indicated chemotherapy.”

In all, 87% of the 685 women aged less than 70 years with a recent diagnosis of nonmetastatic, invasive stage I–III disease reported using some form of CAM at baseline. This was defined as any dietary supplement – including vitamins, minerals, herbal or botanical products and other natural products, for example, fish oil or glucosamine – or mind–body practices, performed alone or with a practitioner, such as yoga or acupuncture.

The majority (89%) of the women for whom chemotherapy was indicated began treatment, as did 36% of the 135 women whose use of chemotherapy was discretionary.

But 71% of patients who did not begin an indicated course of chemotherapy used CAM dietary supplements compared with 28% of those who did begin treatment, with an odds ratio (OR) of 0.16 after adjusting for confounders such as age, race/ethnicity and tumour biomarkers.

Patients with a higher CAM index score – summarising their CAM use – were also significantly less likely to initiate indicated chemotherapy than those with a lower score, with an adjusted OR of 0.64 for each unit increase.

However, use of mind–body practices was not an independent modifier of indicated chemotherapy, nor did CAM use or CAM index score correspond to initiation of discretionary chemotherapy.

In an invited commentary, Robert Zachariae, from Aarhus University Hospital in Denmark, notes that a recent systematic review suggests that patients have varying motivation for CAM use as they move through cancer treatment, including recovery of control, boosting well-being and preventing recurrence.

Acknowledging that a “considerable proportion” of cancer patients are thought not to discuss CAM use with their physician, the commentator writes that the available studies “highlight the urgent need to train oncologists to enhance their ability to improve patient disclosure of CAM”.

“This can best be done in a patient-centered manner by respectfully exploring patients’ preferences and beliefs about CAM and by providing the best evidence-based information about treatment options in a non-judgemental fashion”, he advises.

References

Greenlee H, Neugut AI, Falci L, et al. Association between complementary and alternative medicine use and breast cancer chemotherapy initiation. The Breast Cancer Quality of Care (BQUAL) Study. JAMA Oncol 2016; Advance online publication 12 May. doi:10.1001/jamaoncol.2016.0685

Zacharie R. Complementary and alternative medicine use among patients with cancer. A challenge in the oncologist–patient relationship. JAMA Oncol 2016; Advance online publication 12 May. doi:10.1001/jamaoncol.2016.0713.

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