The picture books were searched on 5 July 2019 and identified were 2,555 potentially relevant picture books using Amazon’s internal search engine and manual searching; 2,509 books were excluded based on titles and abstract reviews. Of the remaining 46 full-text books, 16 were eliminated because of different inclusion criteria. Finally, 30 picture books that met the inclusion criteria were selected (Fig. 1) [16–45]. The picture books included in this study were published from 1988 to 2018 in the United States of America, the United Kingdom, Japan, and Canada. Most of these picture books were written based on the experiences of children diagnosed with cancer, or on information about cancer. HCPs were involved in the development of some picture books. However, there were none based on the survey results for children and families. Most of the picture books directly described the experience with the protagonist’s cancer, and two tried to explain cancer through another story such as an analogy [26, 30]. For example, one book showed cancer as a distinctive flower among the flowers that bloom in the garden. Another book showed cancer as a journey to cure the disease. Some books, which were recommended by cancer-related institutes focused on feelings, not cancer. Word counts ranged from 177 to 2,030 words, and there were more than 5,457 characters in two Japanese picture books [16, 45]. This value corresponded to approximately 2,729 to 3,410 words in English. While the range of reading level was one year and up, some books had no maximum age limit. Some of them did not correlate reading level with the number of pages and words. We summarized the characteristics of the included picture books in Table 1. The main contents of these picture books were identified as (a) cancer-related knowledge, (b) impacts of cancer, and (c) dealing with cancer (Table 2).
Cancer-related knowledge refers to the information about what is going on and what children have to do, including “basic information about cancer” (agreement: substantial), “examinations/procedures” (agreement: substantial), and “treatments” (agreement: moderate).
While some books focused on specific cancer types such as leukaemia and brain tumours, most books focused on the generic term of cancer. They explained that there were many different kinds of cancer. In many books, cancer was generally interpreted as an illness that turned healthy cells into abnormal cells, and the body could not function because they were proliferating. Some books described that cancer was not contagious, and no one knew what causes cancer. It emphasized and explained that it is not caused by their behaviour, thinking, or what they said.
“Mom always knows what I’m thinking. “No one is sure why you have cancer, Clara,” she says. “But we do know that it isn’t because of anything you did, or thought, or said.” “Thank goodness!” I smile. (, p. 11)
Symptoms caused by cancer, such as feeling sick, sleepy, and tired, were described in many books. In most books, symptoms were emerged within the story about the main character who had been diagnosed with cancer, and later recovered from cancer after treatments. A few books mentioned a recurrence of cancer.
Many picture books covered the examinations and procedures such as blood tests, vital sign measurements, bone marrow aspiration, and x-ray. These were described to allay the reader’s fear, for example, that anaesthesia could be taken before undergoing invasive procedures and it makes them fall asleep.
In most books, chemotherapy was described as an effective treatment that could help eliminate cancer cells. Moreover, side effects such as hair loss, fatigue, nausea, and bone marrow suppression were described. Some books dealt with the main topic of hair loss, indicating that patients spent time wearing hats or wig during treatments, and their hair grew back eventually.
Impacts Of Cancer
The impact of cancer refers to the impact of having a child with cancer, including their “daily life” (agreement: moderate), “children’s emotions” (agreement: substantial), and “parent’s emotions” (agreement: almost perfect agreement).
In most books, it was brought up that after the diagnosis of cancer the child's daily life had changed from normal. Hospitalization was often explained. Children's negative and positive emotions were both described. For example, hospitalization separated them from family members and friends, and so they felt alone and sad.
There were descriptions of various types of feelings, such as being sad, scared, angry, embarrassed, and alone. The books described what kind of atmosphere there was for each situation. In the picture story books, emotions were described as the main characters' emotions with a short description of why they felt that way. After they were diagnosed with cancer, they felt sad because they saw their parents cry. They felt scared when they took the treatments, examinations, and procedures. Also, they felt angry and expressed that it was unfair.
“Ally got mad at the cancer. She said, “That is not fair! I do not want to be tired. I want to run and play again. How do we fight the cancer? How do we make it go away?” (, p. 15)
They felt embarrassed of the change in body image when their hair fell out.
“Her hair fell out and when it was gone, her head was white as snow. At first, she felt embarrassed, and sometimes had to cry.” (, ).
On the other hand, there were a few descriptions of positive emotions such as being happy and amazed when they played with their friends; when they reconfirmed their love; when they went back home, and when they recovered from cancer. Some books emphasized that it was normal to have many feelings and that they could tell someone anything.
“I have so many feelings. I don’t know what to do. But I don’t have to feel guilty or ashamed about my feelings. They are a part of me. And it’s okay to let my feelings out.” (, p. 13–15)
Some picture books described parent’s feelings, such as being sad and anxious when their children were diagnosed with cancer. Also, how they were deeply moved when their children recovered from cancer.
Dealing With Cancer
Dealing with cancer refers to the actions to reduce or minimize stressful events that had been described, including “children’s coping strategies” (agreement: almost perfect agreement), message for readers (agreement: almost perfect agreement), and “social support” (agreement: substantial).
Children’s Coping Strategies
The main characters who were diagnosed with cancer tried to cope with the stressful events that they had to do but did not want to do and about which they had negative feelings. For children, stressors varied, such as cancer, treatments, procedures, hair loss, and hospitalization. Also, there were a variety of children’s coping strategies, including emotion-focused coping, which changed their emotional response to the stressor. Another one was problem-focused coping, where they directly approached to the problem. They had a way of coping with stressful events by changing their minds and taking other actions.
“I may lose all of my hair but I hope to win life. Cancer will be beaten. Captain Chemo is on my side.” (, p. 5–6)
Message for Readers
At the end of the story, it was emphasized that the main character was a valuable person and should be loved by others, even if they were diagnosed with cancer..
“The truth about cancer is… It does not define who you are or who you will be. You and only you get to write your story.” (, p. 22)
The main characters were supported by their family members, HCPs, teachers, and friends. They realized that they were not alone and that they were fighting against cancer together. Most of the picture books that mentioned family referred to the parents; few books referred to siblings.
“Since kicking cancer is hard work for our whole family. Mom and Dad make sure we still do a lot of fun things together. It’s great to know I don’t need to kick cancer all on my own.” (, p. 24)