Table 1. Demographics and clinical characteristics of patients in the training cohort and the three validation cohorts.
The results obtained from the training set were further validated in three independent cohorts of patients drawn from a distinct validation set in the PRIMA study (cohort 1), the University of Iowa/Mayo Clinic Lymphoma SPORE (cohort 2) and the Hospital Clinic University of Barcelona (cohort 3).
| Cohort Number of patients |
Training cohort N=134 no./total no. (%)* |
Validation cohort 1 N=172 no./total no. (%)* |
Validation cohort 2 N=186 no./total no. (%)* |
Validation cohort 3 N=102 no./total no. (%)* |
|---|---|---|---|---|
|
| ||||
| Follow-up duration | ||||
| median, IQR (yrs) | 6.6 (6.0-7.0) | 6.8 (6.5-7.1) | 5.5 (3.9-7.8) | 5.8 (4.1-8.7) |
|
| ||||
| Time from biopsy to initial treatment | ||||
| median, range (months) | 1 (0-5) | 1 (0-7) | 0.8 (0-7.2) | 0.7 (0-4) |
|
| ||||
| Baseline characteristics | ||||
| Age > 60 years | 47/134 (35) | 51/172 (30) | 76/186 (41) | 38/102 (37) |
| Male sex | 68/134 (51) | 84/172 (49) | 109/186 (59) | 44/102 (43) |
| Ann Arbor stage III/IV | 123/134 (92) | 158/172 (92) | 149/184 (81) | 77/102 (75) |
| ECOG PS ≥ 1 | 43/134 (32) | 45/172 (26) | 71/185 (38) | 15/101 (15) |
| B symptoms present | 30/134 (22) | 54/172 (31) | 38/184 (21) | 16/101 (16) |
| Bone Marrow involvement | 83/129 (64) | 100/168 (60) | 87/169 (51) | 59/102 (58) |
| Elevated LDH | 43/134 (32) | 57/171 (33) | 59/160 (37) | 25/95 (26) |
| Hemoglobin level < 12 g/dL | 29/134 (22) | 32/172 (19) | 33/169 (20) | 18/94 (19) |
| Elevated β2-microglobulin | 81/128 (63) | 93/159 (58) | 31/43 (72) | 49/92 (53) |
|
| ||||
| FLIPI score | ||||
| 0-1 risk factors | 23/134 (17) | 41/171 (24) | 51/186 (27) | 38/96 (40) |
| 2 risk factors | 53/134 (40) | 56/171 (33) | 62/186 (33) | 32/96 (33) |
| 3-5 risk factors | 58/134 (43) | 74/171 (43) | 73/186 (39) | 26/96 (27) |
|
| ||||
| Histological grade | ||||
| 1-2 | 113/134 (84) | 132/172 (77) | 123/186 (66) | 64/102 (63) |
| 3A | 12/134 (9) | 22/172 (13) | 63/186 (34) | 28/102 (27) |
| Undetermined/other** | 9/134 (7) | 18/172 (10) | 0 | 10/102 (10) |
|
| ||||
| Induction regimen | ||||
| R-CHOP | 128/134 (96) | 157/172 (91) | 96/186 (52) | 102/102 (100) |
| R-CVP | 6/134 (4) | 15/172 (9) | 59/186 (32) | 0 |
| R-Bendamustine | 0 | 0 | 29/186 (16) | 0 |
| other | 0 | 0 | 2/186 (1) | 0 |
|
| ||||
| Maintenance regimen | ||||
| No | 76/134 (57) | 96/172 (56) | 152/186 (82) | 59/102 (58) |
| Yes | 58/134 (43) | 76/172 (55) | 34/186 (18) | 43/102 (42) |
|
| ||||
| Rituximab | 58/58 (100) | 76/76 (100) | 34/34 (100) | 41/43 (95) |
| Ibritumomab-tiotexan | 0 | 0 | 0 | 2/43 (5) |
*
Because of rounding, percentages may not total 100.
**
Undetermined/other included FL of undetermined grade (except 3b), FL with a very small component of DLBCL<10% and FL with diffuse area.
Abbreviations: BM, bone marrow; LDH, lactate dehydrogenase; R, rituximab; CHOP, cyclophosphamide, doxorubicin, vincristine, prednisone; CVP, cyclophosphamide, vincristine, prednisone; FCM, fludarabine, cyclophosphamide, mitoxantrone; NR, not reached.