CONTEXT: Previously reported studies of children with cancer mostly provide cross-sectional knowledge of the prevalence of symptoms but do not show when during the disease trajectory and after the end of successful treatment certain symptoms are most prevalent and/or distressing.

OBJECTIVES: The aim was to describe parents' perceptions of their child's symptom burden longitudinally during and after cancer treatment and to investigate whether parents' perceptions vary with child characteristics and parent gender.

METHODS: One hundred sixty parents (49% fathers) of 89 children answered a modified version of the Memorial Symptom Assessment Scale (MSAS) 10-18 at six different time points from one week after the child's diagnosis (T1) to 12-18 months after the end of successful treatment (T6).

RESULTS: Feeling drowsy, pain, and lack of energy are initially the most prevalent symptoms. During treatment, the most prevalent symptom is less hair than usual. Pain, feeling sad, and nausea are initially the most distressing symptoms. Pain is both prevalent and distressing throughout the treatment. The child's symptom burden decreases over time. There is no difference regarding the reported symptom burden between the parents of a daughter or a son, or parents of a child older or younger than seven years of age. Mothers' and fathers' assessments of the symptom number, total MSAS and the subscales, are associated, but mothers' assessments are often higher than fathers' assessments.

CONCLUSION: The prevalence and distress of symptoms and symptom burden decrease over time. However, even though the cancer is cured, feeling sad is reported as being prevalent and psychological distress is an issue. A dialogue between staff and the family about distressing symptoms and when they can be expected may increase acceptance and adaptation in children and parents during the disease trajectory.