Improved Prognosis for Childhood Acute Lymphocytic Leukemia with Very High White Blood Cell Count (> 100/nl) with Rotation of Non-Cross-Resistant Drug Combinations

Among several initial prognostic factors in acute lymphoblastic leukemia (ALL), i.e., age, hepatosplenomegaly, immunologic subtype, and chromosomal abnormalities [1–4], an elevated white blood count (WBC) at diagnosis has remained the single most important adverse prognostic factor in many studies. In spite of the markedly improved overall prognosis for children with ALL, patients with a WBC > 100/nl still have a risk of relapse of 50% or more [2, 5–7].