Current approach to relapsed acute lymphoblastic leukemia in children

Table 5 Risk stratification after relapse

	BCP			T-cell
	Isolated EM	Combined BM	Isolated BM	Isolated EM	Combined BM	Isolated BM
Risk stratification according to the BFM Group classification[42]
Very early1	Intermediate	High	High	Intermediate	High	High
Early1	Intermediate	Intermediate	High	Intermediate	High	High
Late1	Standard	Intermediate	Intermediate	Standard	High	High
Risk stratification according to the United Kingdom ALLR3 Study classification[30]
Very early1	High	High	High	High	High	High
Early1	Intermediate	Intermediate	High	Intermediate	High	High
Late1	Standard	Intermediate	Intermediate	Standard	High	High
Current approach to risk stratification according to I-BFM SG
Very early1	High	High	High	High	High	High
Early1	Standard	Standard	High	Standard	High	High
Late1	Standard	Standard	Standard	Standard	High	High

¹Very early, less than 18 mo from initial diagnosis; Early: More than 18 mo from initial diagnosis but < 6 mo from completion of primary treatment; Late: More than 6 mo after completion of primary treatment. BCP: B-cell precursor; BM: Bone marrow; EM: Extramedullary; I-BFM SG: International BFM Study Group.