TABLE II.
Abnormalities in BM-PC and BM-Lymphocytes
| Probe | Detected pattern using the probe | % of patients with abnormality in PC | % of (+) patients whose BM lymphocytes have the same abnormality as PC | % of lymphocytes with abnormality. Median (range) |
|---|---|---|---|---|
| Detected by translocation probes | ||||
| BA | any IgH translocation | 47% | 23% | 16% (13-20%) |
| amplification 14q32 | 14% | 9% | 4% | |
| deletion 14q32 | 10% | 18% | 9% (5-37%) | |
| any abnormality | 55% | 20% | ||
| (4;14) | t(4;14) translocation | 12% | 30% | 3% (2-6%) |
| amplification 4p16 | 5.5% | 57% | 6% (4-11%) | |
| amplification 14q32 | 20.5% | 50% | 9 % (4-18%) | |
| deletion 14q32 | 12% | 20% | 12 % (5-19%) | |
| amplification 4p16 plus amplification 14q32 | 5.5% | 71% | 8 % (4-13%) | |
| any abnormality | 50% | 47% | ||
| (11;14) | t(11;14) translocation | 21% | 23% | 5% (2-20%) |
| amplification 11q23 | 26% | 19% | 8 % (4-15%) | |
| amplification14q32 | 12% | 50% | 7% (4-17%) | |
| deletion 14q32 | 5% | 33% | 16 % (5-27%) | |
| amplification 11q23 plus amplification14q32 | 12% | 25% | 7.5% (4-15%) | |
| any abnormality | 72% | 32% | ||
| Detected by deletion probes | ||||
| 13q14 | deletion 13 | 42.5% | 25.5% | 7.7 % (6-30%) |
| trisomy | 3% | 66% | 12.5%(8-17%) | |
| p53 | deletion p53 | 9% | 0% | |
| trisomy 17 | 11% | 33% | 4% (4-5%) | |
| 1q21 | amplification locus | 35% | 0% | |
| trisomy | 20.50% | 31% | 6% (4-34%) | |
| monosomy | 2.5% | 0% | ||
BM slides from 200 MM patients were separately stained with one or more different probes or probe sets; most were stained only with some of the indicated probes. BM slides from a subset of 75 patients were separately stained with all probe sets (see Results and Figure 4). One hundred and thirty-five patients had at least one detectable abnormality with the probe sets used. Amplification of the locus = more than two copies; deletion of the locus = less than two copies; any abnormality = all the abnormalities that could be detected by the probe including translocations, amplifications, and deletions. For six patients with amplification of at least three of the tested chromosomes (1, 4, 11, 14, and 17), although in PC, we detected two signals for chromosome 13, we still considered them as having a deletion following the European Myeloma Network guidelines [39]. Interestingly, three of these six patients have 6–8% of their BM-lymphocytes harboring three signals for ch13, suggesting that loss of the third ch13 occurred only in the PC population.
As determined by a centromeric-specific probe (see Methods section).