Timeliness of diagnosis and treatment: the challenge of childhood cancers.

Cancer represents an important cause of disease-related death in children worldwide. Improved treatment and understanding of the ways in which cancer manifests has allowed for a greater prospect of survival in children of all ages. However, variation in childhood cancer experience exists based on factors at the individual, community and systems levels. Throughout the cancer care continuum these factors may influence the access and timeliness of care a child receives, leading to delays in diagnosis and treatment. The pejorative designation 'delay in diagnosis and treatment' is better characterised as lag time, representing an interval that is thought to influence survival and overall outcome. In recent decades, work has been done to expedite early childhood cancer diagnosis through the creation of screening and education-based programmes. Although systematic cancer screening in children poses risks and fails to achieve the goal of early diagnosis, a case has been made for risk-based surveillance that has been shown to improve outcome and reduce occurrence of advanced stage disease in targeted populations. The components of lag time are examined separately and individually. This review highlights the challenges of early diagnosis in childhood cancers and describes important contributors in the cancer care continuum.