[Complementary or alternative medicine in oncology : Chances or risks?]

Approximately half of all cancer patients use complementary or alternative medicine.

The results of the German S3 guidelines on complementary oncology are presented and placed into the context of patient consultation.

The core recommendations of the S3 guidelines are summarized including an overview of the evidence.

Selected methods of complementary medicine can be used with the aim of improving the quality of life and reducing side effects. Comprehensive data are available for physical activity with respect to survival, quality of life and supportive therapy. For most other methods the evidence is relatively low. Therefore, weighing up the benefits and risks more frequently resulted in negative recommendations in the guidelines, especially for methods based on substances. Exceptions to this are three micronutrients (vitamins B12, D and selenium), as even in the case of a well-balanced diet, deficiency symptoms are possible. Therefore, routine measurement of the blood levels of these micronutrients is recommended.

The questions from patients on what they can do by themselves should be answered respectfully and based on evidence. The benefits and risks of complementary methods must be carefully considered. To do this, regular questioning of patients on the interest in complementary methods is recommended. The decisive benefit of complementary medicine is the chance for patients to become active themselves. Therefore, all recommendations refer to the discussion with the patient, which do not formulate a therapy but are consultation recommendations: should be recommended instead of should be done.