ETP status based on the risk group
| Risk group . | ETP, n = 145 (%) . | Near-ETP, n = 209 (%) . | Non-ETP, n = 902 (%) . | Statistical comparisons . |
|---|---|---|---|---|
| Induction∗ | 38 (26.2%) | 65 (31.1%) | 206 (22.8%) | P < .0001 |
| LR | 5 (3.5%) | 10 (4.8%) | 75 (8.3%) | |
| IR | 38 (26.2%) | 78 (37.3%) | 520 (57.7%) | |
| HR | 55 (37.9%) | 43 (20.6%) | 90 (10.0%) | |
| IF | 9 (6.2%) | 13 (6.2%) | 11 (1.2%) |
| Risk group . | ETP, n = 145 (%) . | Near-ETP, n = 209 (%) . | Non-ETP, n = 902 (%) . | Statistical comparisons . |
|---|---|---|---|---|
| Induction∗ | 38 (26.2%) | 65 (31.1%) | 206 (22.8%) | P < .0001 |
| LR | 5 (3.5%) | 10 (4.8%) | 75 (8.3%) | |
| IR | 38 (26.2%) | 78 (37.3%) | 520 (57.7%) | |
| HR | 55 (37.9%) | 43 (20.6%) | 90 (10.0%) | |
| IF | 9 (6.2%) | 13 (6.2%) | 11 (1.2%) |
HR, high risk; IR, intermediate risk; LR, low risk.
Patients who were enrolled in the study and received induction therapy but did not participate in the second-stage consent were not risk-stratified and were removed from protocol therapy at the EOI. The treatment received by patients taken off the protocol therapy at the EOI was at the discretion of the treating physician and, therefore, varied. For all COG studies, patients were followed up for disease and vital status after they were removed from the protocol therapy. Off-study patients were no longer followed up if they met any of the following criteria: lost to follow-up, withdrawal of consent for further follow-up, enrollment in another COG therapeutic study, death, or the reaching the maximum follow-up 10-year period.