Southwest Oncology Group and Medical Research Council cytogenetic risk category definitions
| Risk status . | SWOG coding . | No. of patients (n = 609) . | MRC coding . | No. of patients (n = 609) . |
|---|---|---|---|---|
| Favorable | inv(16)/t(16;16)/del(16q), t(15;17) with/without secondary aberrations; t(8;21) lacking del(9q) or complex karyotypes | 121 (20%) | inv(16)/t(16;16)/del(16q), t(15;17), t(8;21) with/without secondary abn | 130 (21%) |
| Intermediate | Normal, +8, +6, −Y, del(12p) | 278 (46%)* | Normal, 11q23 abn, +8, del(9q), del(7q), +21, +22, all others | 375 (62%) |
| Unfavorable | del(5q)/−5, −7/del(7q), abn 3q, 9q, 11q, 20q, 21q, 17p, t(6;9), t(9;22) and complex karyotypes (≥ 3 unrelated abn) | 184 (30%) | del(5q)/−5, −7, abn (3q), complex karyotypes (≥ 5 unrelated abn) t(9;22) and t(6;9)† | 104 (17%) |
| Unknown | All other abnormalities | 26 (4%) | Category not recognized | — |
| Risk status . | SWOG coding . | No. of patients (n = 609) . | MRC coding . | No. of patients (n = 609) . |
|---|---|---|---|---|
| Favorable | inv(16)/t(16;16)/del(16q), t(15;17) with/without secondary aberrations; t(8;21) lacking del(9q) or complex karyotypes | 121 (20%) | inv(16)/t(16;16)/del(16q), t(15;17), t(8;21) with/without secondary abn | 130 (21%) |
| Intermediate | Normal, +8, +6, −Y, del(12p) | 278 (46%)* | Normal, 11q23 abn, +8, del(9q), del(7q), +21, +22, all others | 375 (62%) |
| Unfavorable | del(5q)/−5, −7/del(7q), abn 3q, 9q, 11q, 20q, 21q, 17p, t(6;9), t(9;22) and complex karyotypes (≥ 3 unrelated abn) | 184 (30%) | del(5q)/−5, −7, abn (3q), complex karyotypes (≥ 5 unrelated abn) t(9;22) and t(6;9)† | 104 (17%) |
| Unknown | All other abnormalities | 26 (4%) | Category not recognized | — |
SWOG indicates Southwest Oncology Group; MRC, Medical Research Council (United Kingdom); abn, abnormality.
The intermediate group contains 244 patients with normal karyotypes.
Risk status for t(6;9) or t(9;22) is not defined by MRC criteria, presumably due to a lack of these low-frequency aberrations in their cohort.