Risk stratification schemes for first relapse
| Risk status . | Definition . |
|---|---|
| COG, North America17 | |
| Low | Late B-ALL marrow, end-block 1 MRD < 0.1% Late IEM, end-block 1 MRD < 0.1% |
| Intermediate | Late B-ALL marrow, end-block 1 MRD ≥ 0.1% Late IEM, end-block 1 MRD ≥ 0.1% |
| High | Early B-ALL marrow |
| Early IEM | |
| T-ALL relapse, any site and timing | |
| BFM Group, Western Europe14 | |
| Low (S1) | Late IEM relapses |
| Intermediate (S2) | Very early and early IEM relapses Late B-ALL isolated marrow relapses Early/late B-ALL combined relapses |
| High (S3 and S4) | Very early and early B-ALL marrow relapses |
| Very early B-ALL combined relapses | |
| T-ALL marrow relapses (regardless of timing) | |
| Cancer Research UK Children’s Cancer Group, United Kingdom15 | |
| Standard | Late IEM relapse |
| Intermediate | Early IEM relapse Late isolated B-ALL marrow relapse Early/late combined B-ALL marrow relapse |
| High | Very early IEM relapse |
| B-ALL early isolated marrow elapse | |
| B-ALL very-early marrow or combined relapse | |
| T-ALL marrow or combined relapse, any timing | |
| Risk status . | Definition . |
|---|---|
| COG, North America17 | |
| Low | Late B-ALL marrow, end-block 1 MRD < 0.1% Late IEM, end-block 1 MRD < 0.1% |
| Intermediate | Late B-ALL marrow, end-block 1 MRD ≥ 0.1% Late IEM, end-block 1 MRD ≥ 0.1% |
| High | Early B-ALL marrow |
| Early IEM | |
| T-ALL relapse, any site and timing | |
| BFM Group, Western Europe14 | |
| Low (S1) | Late IEM relapses |
| Intermediate (S2) | Very early and early IEM relapses Late B-ALL isolated marrow relapses Early/late B-ALL combined relapses |
| High (S3 and S4) | Very early and early B-ALL marrow relapses |
| Very early B-ALL combined relapses | |
| T-ALL marrow relapses (regardless of timing) | |
| Cancer Research UK Children’s Cancer Group, United Kingdom15 | |
| Standard | Late IEM relapse |
| Intermediate | Early IEM relapse Late isolated B-ALL marrow relapse Early/late combined B-ALL marrow relapse |
| High | Very early IEM relapse |
| B-ALL early isolated marrow elapse | |
| B-ALL very-early marrow or combined relapse | |
| T-ALL marrow or combined relapse, any timing | |
COG definitions: IEM relapse (<18 mo from diagnosis), late IEM (≥18 mo from diagnosis); early marrow relapse (<36 mo from diagnosis), and late marrow relapse (≥36 mo from diagnosis).
BFM and UK definitions: very early (<18 mo from diagnosis), early (18 mo from diagnosis but <6 mo after completion of treatment), and late (≥6 mo after completion of treatment).
IEM, early isolated extramedullary.