Table 1.
Patients' baseline characteristics.
| Characteristics | Training cohort (n = 130) | Validation cohort (n = 61) | P |
|---|---|---|---|
| Age, years, mean (SD) | 59 (9) | 59 (11) | 0.736 |
| Sex, n (%) | 0.884 | ||
| Male | 71 (54.6) | 34 (55.7) | |
| Female | 59 (45.4) | 27 (44.3) | |
| Clonal bone marrow plasma cells, %, Median (IQR) | 17 (7–41) | 21 (8–39) | 0.333 |
| CPC, %, median (IQR) | 0.005 (0.000–0.122) | 0.009 (0.000–0.135) | 0.718 |
| CPC status, n (%) | 0.748 | ||
| ≤ 0.038% | 82 (63.1) | 37 (60.7) | |
| >0.038% | 48 (34.9) | 24 (39.3) | |
| Hemoglobin, g/L, mean (SD) | 98 (25) | 93 (26) | 0.184 |
| Albumin, g/L, mean (SD) | 37.0 (6.6) | 36 (5) | 0.104 |
| Creatinine, μmol/L, median (IQR) | 80.0 (61.8–119.2) | 91.9(61.0–223.7) | 0.234 |
| β2-MG, mg/L, median (IQR) | 4.1 (2.7–7.7) | 5.4 (2.9–10.8) | 0.222 |
| LDH, U/L, median (IQR) | 194 (160–250) | 184 (146–271) | 0.884 |
| hs-CRP, mg/L, median (IQR) | 0.87 (0.00–9.04) | 2.72 (0.21–8.31) | 0.222 |
| Extramedullary myeloma, n (%) | 12 (9.2) | 3 (4.9) | 0.457 |
| Type, n (%) | 0.070 | ||
| IgG | 60 (46.2) | 34 (55.7) | |
| IgA | 35 (26.9) | 7 (11.5) | |
| IgD | 9 (6.9) | 8 (13.1) | |
| Other | 26 (20.0) | 12 (19.7) | |
| High-risk CA, n (%) | 58 (44.6) | 34 (55.7) | 0.151 |
| D-S, n (%) | 0.361 | ||
| I | 15 (11.5) | 5 (8.2) | |
| II | 28 (21.5) | 9 (14.8) | |
| III | 87 (66.9) | 47 (77.0) | |
| ISS, n (%) | 0.103 | ||
| I | 37 (28.5) | 13 (21.3) | |
| II | 48 (36.9) | 17 (27.9) | |
| III | 45 (34.6) | 31 (50.8) | |
| R-ISS, n (%) | 0.466 | ||
| I | 29 (22.3) | 11 (18.0) | |
| II | 71 (54.6) | 31 (50.8) | |
| III | 30 (23.1) | 19 (31.1) | |
| First line therapy regimens, n (%) | 0.705 | ||
| PIs-containing regimens | 108 (83.1) | 52 (85.2) | |
| IMiDs-based regimens | 22 (16.9) | 9 (14.8) | |
| ASCT, n (%) | 8 (6.2) | 1 (1.6) | 0.314 |
| Response rates, n (%) | |||
| VGPR or better | 67 (51.5) | 29 (47.5) | 0.606 |
| PR or better | 98 (75.4) | 48 (78.7) | 0.616 |
CPC, circulating plasma cells; β2-MG, β2-microglobulin; LDH, lactate dehydrogenase; hs-CRP, hypersensitive C-reactive protein; High-risk CA, High-risk Cytogenetic abnormalities, D-S, Durie-Salmon staging system; ISS, International Staging System; R-ISS, Revised-International Staging System; PIs, proteasome inhibitors; IMiDs, immunomodulatory drugs; ASCT, autologous hematopoietic stem cell transplantation; VGPR, very good partial response; PR, partial response.