Goals of work: There is little data on the prevalence of use of dietary supplements in cancer, especially in light of the growing evidence that some dietary supplements can have adverse interactions with conventional cancer treatment. The purpose of this study was to investigate the use of dietary supplements among adult cancer patients in a community hospital comprehensive cancer center.
Patients and methods: A survey of 227 new adult cancer patients presenting for treatment for the first time at Cancer Treatment Centers of America at Midwestern Regional Medical Center, between November 2001 and October 2003. Patients completed the McCune Questionnaire, a validated instrument that captures information on the use of 56 dietary supplements in cancer, at admission to the hospital.
Results: Of the 227 patients, 73% used some form of dietary supplements during the 30 day period before the survey was conducted. Dietary supplement use was significantly higher (p = 0.04) in patients with colorectal (80%) and breast (75%) cancer as compared to patients with lung cancer (53%). Patients with stage II (86%) and III (76%) disease at diagnosis were more likely (p = 0.02) to use dietary supplements as compared to those with stage I (71%) disease at diagnosis, while those with stage IV (61%) disease at diagnosis were least likely to use them. Of the 80 patients who had received chemotherapy within the last 30 days, 71% had also used dietary supplements in that timeframe and 25% had consumed one or more herbal therapies that are suspected to have adverse interactions with chemotherapy. Of the 57 patients combining chemotherapy with dietary supplements, 52.6% did not consult a healthcare professional.
Conclusions: In our study, twenty-five percent of patients receiving chemotherapy were concurrently using dietary supplements suspected to have adverse interactions with chemotherapy, usually relying on information sources other than healthcare professionals. Given the prevalence rates of these agents, healthcare providers should systematically inquire about them, and consider the potential for drug-dietary supplement interactions in treatment planning.