• There are unique issues to consider when caring for an older adult with cancer.• The biologic characteristics of certain cancers and their responsiveness to therapy may be different in older patients compared to their younger counterparts.• The psychologic and psychosocial changes associated with aging may impact an older adult’s ability to tolerate cancer therapy and should be considered in the treatment decision-making process.• Advanced age alone should not be the only criterion to preclude effective treatment that could improve quality of life (QOL) or lead to a survival benefit in older patients.• These age-related issues form the basis for the development of NCCN Guidelines for Older Adult Oncology that address special considerations in older patients with cancer.