Dear Colleagues,

The development of the civilization, technical, economic and industrial progress, apart from the obvious positive changes, has also caused the disturbance of the internal homeostasis of the organism, due to the constant influence of various harmful external factors, the occurrence of which is related to civilization development. Because of such changes, a person in every period of their life, from conception to adulthood, is exposed to the influence of carcinogenic factors that cause the malignant transformation of the cell, i.e., formation of cancer. Neoplastic diseases, classified as civilization diseases are the second, after poisoning, most common cause of death in children aged over one year, and it is expected that in the first decade of this century, one person out of 900 adults between 18 and 44 years of age will be recovered from childhood cancer. In Europe, there are approximately 15,000 new cases of cancer every year among children from 0 to 14 of age, and an additional 20,000 new cases among adolescents and young adults aged 15–24. There are countries where the incidence of childhood cancer exceeds 150 cases among 1 million children, e.g., Nigeria, Brazil, New Zealand, Sweden and Australia. It is estimated that in 2020, approximately 16,850 children and adolescents aged 0–19 will be diagnosed with cancer and 1730 will die from the disease. In the United States, it is estimated that approximately 11,050 new cases of cancer will be diagnosed in children from birth to 14 years of age in 2020, and approximately 1190 children are expected to die from the disease. Although cancer mortality rates in this age group fell by 65% between 1970 and 2016, cancer remains the leading cause of disease death in children. The most common types of cancer diagnosed in children 0–14 years of age are leukaemias, brain tumours and other tumours of the central nervous system, and lymphomas. The highest incidence of ALL is observed in the USA, Australia, Germany and Costa Rica and amounts to 32–44%, while in most European countries, it affects 23–29% of the population. The lowest incidence is observed in China (19.6%), India (11%), Japan (21%), New Zealand (12%) and Brazil (11.4%). The prevalence of ANLL is similar across geographies, except for Japan and some African countries where ANLL is more common than ALL. The incidence of cancer of the central nervous system in England and Wales is 16.21%, in France 16.85%, in Germany 20.0%, and in Hungary as much as 26.5%. There are differences in the incidence of different types of cancer depending on race. Ewing's sarcoma and testicular malignancies are mainly of the white race, Wilms' tumour is less common in Asia than in Europe and the United States, and more common in the black race. In turn, acute lymphoblastic leukaemia is diagnosed twice as often in white people than black people.

A child's cancer affects their entire family and is a source of chronic stress for a sick child, as well as for their parents and siblings. It deprives the feeling of security, introduces uncertainty, fear, and destabilizes the current life. It mobilizes the family, who must reconcile the treatment of the disease, frequent visits to the hospital with the hardships of everyday life. The emotional burden the family has to deal with is enormous. Families do not forget about the irreversibility and longevity of the disease, about the fact that the child will suffer physical and mental suffering, and is constantly accompanied by concern for the life and health of a loved one. At the same time, all everyday life becomes subordinate to illness. Goals, priorities, values, plans for the near and further future are changing. The family learns to function in new circumstances, to cope with difficulties, experience difficult emotions and conflicts. It has to reconcile the requirements of caring for a sick child with professional work, concern for finances, caring for healthy siblings and contacts with the surrounding social environment. This makes the cancer treatment process difficult, burdensome and sometimes even unacceptable for the whole family.

The purpose of this Special Issue in Children is to draw attention to the physical, psychological and social problems of both children with cancer and their families. We encourage you to submit research results, scientific thoughts and experiences.

Dr. Anna Lewandowska
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Children is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2400 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

• cancer
• problems of children with cancer
• the problem of families of children with cancer