Cancer has become a prevalent disease, affecting millions of new patients globally each year. The COVID-19 pandemic is having far-reaching impacts around the world, causing substantial disruptions to health and health care systems that are likely to last for a prolonged period. Early data have suggested that having cancer is a significant risk factor for mortality from severe COVID-19. A diverse group of medical oncologists met to formulate detailed practical advice on systemic anticancer treatments during this crisis. In the context of broad principles, issues including risks of treatment, principles of prioritizing resources, treatment of elderly patients, and psychosocial impact are discussed. Detailed treatment advice and options are given at a tumor stream level. We must maintain care for patients with cancer as best we can and recognize that COVID-19 poses a significant competing risk for death that changes conventional treatment paradigms.