(Reuters Health) – One in three U.S. patients with a cancer diagnosis has recently used non-standard therapies to manage their disease – but many haven’t told their doctors, survey data suggest.

Among patients who said they used so-called complementary and alternative therapies, such as herbal supplements and yoga, nearly 30 percent did not disclose this use to their physicians, researchers wrote in a letter published in JAMA Oncology.

Cancer patients using alternative therapies may hesitate to tell doctors