Providing effective and tolerable cancer treatment for the growing number of older adult patients who have cancer will require an understanding of the role of aging, comorbidity, functional status, and frailty on treatment outcomes. The incorporation of CGA into the care of older patients who have cancer will ensure that the heterogeneity of this population is considered in the development of treatment plans. It also may improve outcomes by identifying and optimally treating comorbid conditions and functional impairments. Optimal treatment of the older adult patient who has cancer starts with careful delineation of goals through conversation. The treatment plan should be comprehensive and address cancer-specific treatment, symptom-specific treatment, supportive treatment modalities, and end-of-life care.