Table 4.
RNA-based analysis of equivocal ALK cases; 75% (6/8) of FISH-BL-positive cases were negative, 25% (2/8) were positive with both RNA-based methods. All FISH-BL-negative cases were ALK fusion negative with MPS and digital probe-based assay
| Sample | IHC | FISH | Massive Parallel Sequencing (MPS) (IonTorrent) | Probe-Based Assays (NanoString) | Fusion | ||||
|---|---|---|---|---|---|---|---|---|---|
| Fusion | 3′/5′ | Fusion | 3′/5′ | ||||||
| IHC-uncertain/FISH-BL-positive | |||||||||
| P19 | ± | + | – | – | – | – | |||
| IHC-positive/FISH-BL-positive | |||||||||
| P20 | + | + | + | + | ± | ± | + | + | V3a/b |
| P21 | + | + | + | + | + | + | V1 | ||
| IHC-negative/FISH-BL-positive | |||||||||
| P22 | – | + | – | – | – | – | |||
| P23 | – | + | – | NA | – | NA | – | – | |
| P24 | – | + | – | – | – | ± | |||
| P25 | – | + | – | – | – | – | |||
| P26 | – | + | – | – | – | – | |||
| IHC-negative/FISH-BL-negative | |||||||||
| P27 | – | – | – | – | – | – | – | – | |
| P28 | – | – | – | – | – | – | |||
| P29 | – | – | – | – | – | – | |||
| P30 | – | – | – | – | – | – | |||
| IHC-negative/FISH-positive | |||||||||
| P31 | – | + | – | – | – | – | |||
| P32 | – | + | – | – | – | – | |||
| P33 | – | + | – | – | – | – | |||
Fusion: fusion detection with amplicons/probes covering ALK fusion breakpoint; 3′/5′: fusion detection with amplicons/probes covering 3′ and 5′ end; NA: Not Analyzable; ND: Not Determined; +: fusion detected; −: fusion not detected; ±: fusion uncertain; V1: EML4_13:ALK_20; V3a: EML4_6a:ALK_20; V3b: EML4_6b:ALK_20