Cancer patients not only exhibit physical care problems, but also have various psychological, social, and existential problems which cause stress that can induce psychological disorders. Psychological distress causes suffering in patients and negatively impacts their treatment. Therefore, appropriate interventions are required. Family caregivers also suffer from mental and physical burdens that cause poor health, leading them to being called "second order patients," and necessitating their own treatment and care. Thus, cancer treatment involves biological and humanistic approaches. Psycho-oncology deals with the humanistic aspects of cancer treatment to help reduce the psychological burden of patients. Bereavement is one of the most stressful events that a family experiences. Intervention is sometimes needed for mental, physical, and social reactions to grief in the family. Bereavement care, "postvention," is considered effective for reducing the family's stress.