Older patients with cancer are different physically, psycho-spirituality, and socio-economically, and when considering the indications for chemotherapy and other drug therapies for cancer, it is important to comprehensively assess their condition and risk using geriatric assessment(GA). Multidisciplinary team-based approach is essential to address impaired domains that are found by GA. The G8 screening is useful tool for screening the GA candidates. In recent years, there have been increasing opportunities that older patients with cancer who receive immunotherapy with immune checkpoint inhibitors. There is no consensus on the treatment and management of immune-related adverse events(irAEs)specific to older patients, and therefore it is important to adhere to an evidence-based approach.