Cancer is largely a disease of older people. In the US, almost 60% of cancer diagnoses and 70% of cancer deaths are in people over the age of 65. Moreover, 70% of cancer survivors are 70+ years of age. With the rapidly aging population across the world, dealing with the older cancer patient is of paramount importance. The reason for the link between cancer and aging is poorly understood, but theories include issues relating to DNA instability, tumor suppressor defects, telemere shortening and the senescent microenvironment. Older patients require particular attention because they differ in substantial ways from younger adults including greater heterogeneity, physiologic changes, increased prevalence of, and multiple comorbidities, atypical presentations of disease, increased rate of adverse effects of medications and often-different goals of care. To address these issues, screening instruments and comprehensive geriatric assessment approaches have been developed to more accurately assess the multifaceted array of factors that contribute to the state of health and functional status of older complex patients. These include physical and cognitive function, multiple morbidities, nutritional, psychosocial, spiritual, and medication status. The goals of such assessments include prediction of outcomes, patient selection for treatment, management during treatment and survivorship management and are being increasingly realized in clinical trials. There are however substantial gaps in our knowledge regarding appropriate oncologic management of vulnerable older adults since such patients have often been excluded from clinical trials on the basis of advanced age or comorbidities. Trials are how being designed to address age specific issues in a number of different tumor types. A 2013 Institute of Medicine report calls for increased attention to these issues.