[Tumor markers of childhood cancer]

Tumor markers are the substances which are produced from malignant cells and are detectable from peripheral blood or body fluid. These markers are used for the evaluation of treatment effectiveness or the detection of relapse. In most cases of pediatric cancer, specific molecular abnormalities of tumor cells have been able to be identified. Evaluation of these molecular markers is critical for the diagnosis and the choice of treatment. Recently, these molecular markers have also come to be used for the detection of minimal residual disease. Such a system can be regarded as a kind of tumor marker.