Integrative oncology focuses on the roles of complementary therapies to increase the effectiveness of conventional cancer treatment programs by improving defined outcomes such as symptom control, quality of life, rehabilitation, and prevention of recurrence. Implementation of integrative oncology programs should be based on the best evidence and must continually be evaluated to ensure quality, optimization of techniques, collection of new data, and cost-effectiveness. Useful domains that can be evaluated include symptom control, adherence to treatment protocols, quality of life, individual outcomes, prevention, rehabilitation, potential advantages of a whole-systems health approach, and economics of health services.