Introduction:
The family is the fundamental unit of society, a system made up of components that together form a whole. The appearance of cancer in the family completely changes the life not only of the patient but also the whole system. There are changes in thoughts, feelings and actions, also changes to the hierarchy of the pursued objectives and values, changes in mood and activity of individual family members. These changes, however, depend on the phase of the disease and its treatment.

Aim:
The aim of this paper is to present some selected issues of psycho-oncology of a family, i.e. a family situation, according to the stage of cancer, the family system in the context of cancer, impact of the disease on the family life cycle, as well as to discuss the situation in the face of a child cancer parent, based on a review of research.

Knowledge:
Phase cancer affects the family system. The diagnosis phase is usually accompanied by anxiety and fear. In the treatment phase there is often a close emotional support by partners. In the period of remission, the family system returns to the former social roles. There is also the so-called Damocles syndrome. During relapse, there occurs anxiety, a sense of failure and sadness. Characteristics of families with cancer are increases in the demand for proximity, the blurring of boundaries between family members, maintaining homeostasis, and limited communication. Also, the phase of marriage affects the family system in the face of illness. In couples married for a short time, cancer can cause intense crisis. Children whose parents who are ill with cancer, experience a particular crisis. Adolescents tend to show a higher level of emotional problems than children of school age.

Summary:
Cancer disrupts the functioning of the family. At every stage of the disease, the psychological support of patients and their families is important. An integrated model of care for patients with cancer and their families is recommended.