Detection of Minimal Residual Leukemia by Polymerase Chain Reactions

Over the past two decades substantial progress has been made in the therapy of human leukemias. This development can be illustrated by the success in the treatment of the most frequent neoplasia in childhood, acute lymphoblastic leukemia (ALL). Application of the BFM protocol induces complete clinical and hematological remission in 98% of patients [15]. However, the reduction of leukemia cell burden below the detection level of morphological examination by no means indicates a complete eradication of the leukemia cell population. Various multicenter trials have empirically established that a 2 years’ intensive chemotherapy is necessary in order to achieve a cure rate of, by now, 75% in children. Despite these impressive advances two related clinical problems remain a challenge for today’s oncology. On one hand a significant number of the eventually cured patients may in fact receive overtreatment, while on the other hand 25% of the children with ALL still relapse, a clinical course associated with a very poor prognosis.