Overview of biology and genetics of childhood cancer

Cancer is a multistep process that originates in a single cell which develops genetic or epigenetic defects. Typically these aberrations occur in tumour suppressor genes, oncogenes or DNA repair genes, and enable the cell to proliferate uncontrollably. Cancer is a spectrum of diseases, from benign tumours that do not develop distant disease, to more aggressive, malignant tumours that can be locally invasive or metastasise to distant sites via the vascular or lymphatic system. In childhood, cancer is either sporadic, where the cause is unknown, or associated with constitutional abnormalities and cancer pre-disposition syndromes. In recent decades, improved survival rates in childhood cancer has traditionally been associated with refinement of historic therapies and treatment protocols. However a greater understanding of cancer biology has enabled the use of molecular diagnostics to; robustly identify tumour types, stratify treatment groups according to associated outcomes, and develop molecularly targeted therapies or immunotherapies that harnesses the power of the immune system to destroy cancer cells. As this expansion of knowledge and experience continues, treatment of childhood cancer will focus on improving survival rates, reducing short and long-term toxicities and developing more biologically tailored therapies and stratified treatment protocols.