NEW YORK (Reuters Health) – The majority of cancer patients use “complementary methods” (CMs) in addition to conventional treatment, aimed at relieving symptoms and side effects and increasing overall wellness, according to findings from a large, population-based study.

“We receive thousands of phone calls each year about CMs at the American Cancer Society (ACS) national cancer information center, and our web pages on CM are among the most popular on our website,” lead author Dr. Ted Gansler told Reuters Health.

“The very large number of randomly chosen volunteers in the ACS Studies of Cancer Survivors and the availability of personal, medical, and psychological information provided an opportunity to study this topic in very precise detail and in some new ways,” he added.

The study by the Atlanta-based research team, reported in the September 1 issue of Cancer, included 4139 adults diagnosed with one of 10 high-incidence cancers who were surveyed 10 to 24 months after diagnosis.

Of 19 CMs included in the survey, the most frequently cited was prayer/spiritual practice, reported by 61% of respondents. Use of relaxation, faith/spiritual healing, and nutritional supplements/vitamins were each reported by more than 40%. Between 10% and 15% of respondents were involved in meditation, religious counseling, massage, and support groups.

Predictors of CM use were female gender, younger age, white race, higher income, and educational achievement. However, African Americans had a greater tendency to use “mind-body methods,” including spiritual practices.

“One result we find especially interesting is the substantial difference in use of CMs by gender and type of cancer,” Dr. Gansler said. The gender gap was particularly wide for energy medicine (tai chi and yoga) and for massage, while CMs in general were much more popular among breast and ovarian cancer survivors than among people with other cancers.

“Although complementary care providers at major cancer centers have conducted research on quality-of-life outcomes, I’d like to see that even more,” the researcher continued.

“Learning more about which CMs help cancer survivors with pain, fatigue, anxiety, depression, overall psychological adjustment, and overall physical functioning is very feasible,” Dr. Gansler noted. “That information could increase attention and resources for providing CMs that are helpful and reducing the time and money spent on ones that are not.”

For example, “recent studies suggest that acupuncture helps relieve some symptoms of cancer and some side effects of treatment, but it was used by only 1.2% of participants in our study.”

“On the other hand, vitamins seem to be very popular,” Dr. Gansler said. “Nonetheless, with the exception of people with clinically diagnosed deficiencies or those unable to eat enough, there is little evidence that high-dose vitamins help people with cancer and there is increasing evidence that high doses of some vitamins can be harmful.”

Cancer 2008;113:1048-1057.