Use of complementary, alternative medicine affects initiation of chemotherapy

Women with early-stage breast cancer for whom chemotherapy was indicated and who used dietary supplements and multiple types of complementary and alternative medicine (CAM) were less likely to start chemotherapy than nonusers of alternative therapies, according to latest research led by Heather Greenlee, ND, PhD, associate professor of Epidemiology at Columbia University's Mailman School of Public Health. This is one of the first studies to evaluate how complementary and alternative medicine use affects decisions regarding chemotherapy. Findings are available in JAMA Oncology.

Dr. Greenlee and colleagues studied a group of 685 women with early-stage breast cancer who were recruited from Columbia University Medical Center, Kaiser Permanente Northern California, and Henry Ford Health System and enrolled 2006-2010. The women were younger than 70 with non-metastatic invasive breast cancer.

The study included five types of complementary therapies: the dietary supplement use of vitamins/minerals, herbs/botanicals, and other natural products, as well as mind-body self-practice, and mind-body practitioner-based.

Use of alternative therapies was reported by the large majority of the women studied--87 percent. By 12 months, chemotherapy was initiated by 89 percent of women for whom chemotherapy was indicated. The remaining group of women for whom chemotherapy was discretionary had a much lower rate of initiation--at 36 percent. Nearly half (45 percent) were clinically indicated to receive chemotherapy per National Comprehensive Cancer Network guidelines.

Not all women initiate adjuvant treatment for breast cancer despite the survival benefits associated with it. The decision to start chemotherapy involves psychosocial factors, belief systems, and clinical, demographic and provider characteristics.

Complementary and alternative therapy use among patients with breast cancer has increased in the past two decades. The most commonly used complementary and alternative therapies were dietary supplements and mind-body practices. On average, the women used two such therapies, although nearly 40 percent of the women reported using three or more complementary and alternative therapies.

The use of mind-body practices was not related to chemotherapy initiation. However, dietary supplements usage and a higher simultaneous use of multiple complementary and alternative therapies among women for whom chemotherapy was indicated were associated with a lower likelihood to initiate chemotherapy than nonusers, according to the results. There was no association between starting chemotherapy and using alternative medicine among women for whom chemotherapy was discretionary.

Greenlee suggests that it is important to consider possible alternative explanations for their findings. For example, it is unclear whether the association between complementary and alternative medicine use and chemotherapy non-initiation reflects long-standing decision-making patterns among study participants. It is possible that women who did not initiate treatment and who were alternative therapy users were long-time users of CAM and chose complementary medicine as an alternative to conventional chemotherapy. However, the study did not assess prior complementary and alternative medicine use and therefore cannot rule out this possibility.

"Though the majority of women with clinically indicated chemotherapy initiated treatment, 11 percent did not. A cautious interpretation of results may suggest to oncologists that it is beneficial to ascertain use of complementary and alternative medicine therapy among their patients, especially dietary supplement use, and to consider use of alternative treatment as a potential marker of patients at risk of not initiating clinically indicated chemotherapy," Greenlee said.

Source: Columbia University's Mailman School of Public Health