This is a clinical practice guideline for oncology clinicians on how to use effective communication to optimize the patient-clinician relationship, patient and clinician well-being, and family well-being. The guideline examines the core communication skills and tasks that apply across the continuum of cancer care. Topics include the discussion of goals of care and prognosis, treatment selection, end-of-life care, facilitating family involvement in care, and clinician training in communication skills.