Table 2.
Univariate Cox proportional hazards analysis of risk factors of progression to clinical MM requiring therapy
| Variable | n/N (%) | Time to MM requiring therapy | |
|---|---|---|---|
| HR (95% CI) | P value | ||
| Age ≥65 y | 143/331 (43%) | 2.21 (1.28, 3.81) | .004 |
| Female | 153/331 (46%) | 0.62 (0.35, 1.08) | .093 |
| SWOG performance status 0 | 228/327 (70%) | 0.80 (0.45, 1.43) | .452 |
| Hemoglobin <12 g/dL | 84/331 (25%) | 2.01 (1.15, 3.49) | .014 |
| Platelets <240 × 103/μL* | 206/331 (62%) | 1.47 (0.83, 2.62) | .189 |
| Albumin <4 g/dL* | 154/329 (47%) | 1.90 (1.10, 3.28) | .021 |
| Serum B2M >3 mg/L* | 86/322 (27%) | 2.61 (1.51, 4.49) | <.001 |
| Serum B2M >5.5 mg/L | 17/322 (5%) | 1.23 (0.38, 3.93) | .732 |
| Bone marrow PCs ≥10% | 176/330 (53%) | 7.78 (3.32, 18.20) | <.001 |
| Bone marrow PCs ≥20%* | 84/330 (25%) | 4.94 (2.86, 8.54) | <.001 |
| Bone marrow PCs ≥60% | 2/330 (1%) | 6.54 (0.90, 47.55) | .063 |
| Serum M-protein ≥3 g/dL* | 34/330 (10%) | 5.48 (3.08, 9.78) | <.001 |
| IgA isotype M-protein | 45/313 (14%) | 1.44 (0.72, 2.86) | .299 |
| IgG isotype M-protein | 264/313 (80%) | 0.93 (0.48, 1.81) | .840 |
| Uninvolved immunoglobulins low† | 212/309 (69%) | 4.05 (1.73, 9.48) | .001 |
| κ light chain clonal isotype | 190/303 (63%) | 1.08 (0.61, 1.91) | .787 |
| Involved SFLC >25 mg/dL* | 42/228 (18%) | 3.71 (2.01, 6.83) | <.001 |
| Involved/uninvolved SFLC ratio >10* | 79/228 (35%) | 3.54 (1.92, 6.52) | <.001 |
| Abnormal metaphase cytogenetics | 24/250 (10%) | 1.67 (0.75, 3.73) | .210 |
| GEP 70-gene risk >−0.26* | 37/126 (29%) | 5.85 (2.56, 13.34) | <.001 |
| GEP poly-PC >11.60* | 62/126 (49%) | 0.17 (0.06, 0.48) | .001 |
| GEP PI >−2.73* | 50/126 (40%) | 4.41 (1.84, 10.58) | <.001 |
| GEP CD-1 subgroup | 6/126 (5%) | 0.00 (0.00, NE) | .989 |
| GEP CD-2 subgroup | 28/126 (22%) | 0.64 (0.22, 1.86) | .413 |
| GEP HY subgroup | 31/126 (25%) | 1.48 (0.64, 3.43) | .361 |
| GEP LB subgroup | 28/126 (22%) | 0.62 (0.21, 1.80) | .374 |
| GEP MF subgroup | 17/126 (13%) | 0.54 (0.13, 2.31) | .407 |
| GEP MS subgroup | 11/126 (9%) | 2.36 (0.81, 6.88) | .116 |
| GEP PR subgroup | 5/126 (4%) | 4.56 (1.35, 15.35) | .014 |
| MRI focal lesions ≥1 | 25/156 (16%) | 2.81 (1.19, 6.65) | .018 |
| MRI focal lesions >1 | 9/156 (6%) | 4.71 (1.57, 14.11) | .006 |
| Center-University of Arkansas | 246/331 (74%) | 1.30 (0.65, 2.59) | .452 |
P value from Wald χ2 test in Cox regression.
CD-1, cyclin D-1; CD-2, cyclin D-2; CI, confidence interval; HR, hazard ratio; HY, hyperdiploid; MS, multiple myeloma-SET; NE, not estimable; PI, proliferation index.
*
Optimal cut-points when applicable are based on approximate running log-rank test statistic.
†
Uninvolved immunoglobulins low: <600 mg/dL if IgG, <50 mg/dL if IgM, <100 mg/dL if IgA.