Complementary and alternative medicine use in radiotherapy: what are patients using?

Complementary and alternative medicine (CAM) use by patients could interact in unpredictable ways with conventional therapies. This trial was designed to study the prevalence, types, and clinical implications of CAM use in patients with cancer who are receiving radiotherapy.

A validated questionnaire was given to consenting outpatients in this ethics-approved study. Questions specified types of CAM used, clinician knowledge, reason for use, perceived effectiveness, safety, and cost.

Of the 101 assessable questionnaires, 38 patients (38%) of the total patient group used CAM, with vitamins (53%), antioxidants (29%), spiritual/meditation practices (29%), and herbs (18%) being the most commonly used. The intention of CAM use was to improve quality of life in 69% of patients and for either hope of cure or to assist other forms of treatment in 26%. The majority of patients (58%) were using CAM prior to their diagnosis of cancer, with 40% starting at diagnosis or during conventional treatment. Patients spent up to $300/month on CAM use. Patients using CAM were significantly more likely to also receive chemotherapy versus non-CAM users (45% versus 24%, p=0.045). Significantly fewer CAM users expected cure from conventional therapy, compared to non-CAM users (50% versus 75%, p=0.016). More CAM users expected conventional therapy to prolong life (58% versus 32%, p<0.001). Only 40% discussed CAM use with their oncologists.

CAM is commonly used by patients with cancer. CAMs, particularly antioxidants, are being taken which could negate the underlying free-radical tumorcidal effects of radiotherapy. Oncologists need to have greater awareness of this use and of its potential adverse consequences.