Validation of a registry-derived risk algorithm based on treatment protocol as a proxy for disease risk in childhood acute lymphoblastic leukemia

Table 1 Biology-based risk algorithms using data available from chart review

	Age (years)		WBC (x10⁹/L)		Immunophenotype		Cytogenetics^&		MRD^#
	1 - 9	<1, ≥10	<50	≥50	B	T	Low risk	High risk	Negative	Positive
Algorithm 1*	SR	HR	SR	HR	-	-	-	-	-	-
Algorithm 2*	SR	HR	SR	HR	SR	HR	-	-	-	-
Algorithm 3*	SR	HR	SR	HR	SR	HR	SR	HR	-	-
Algorithm 4*	SR	HR	SR	HR	SR	HR	SR	HR	SR	HR

HR High risk, MRD Minimally residual disease, SR Standard risk, WBC White blood cell.
*For each algorithm, patients were classified as standard risk only in the absence of any high risk feature.
^&High risk cytogenetics included t(9;22) (BCR-ABL), hypodiploidy (<45 chromosomes), or any 11q23 (MLL) rearrangement.
^#MRD positivity was defined as ≥0.01 residual blasts.

ISSN: 1471-2288