TABLE 1.
Distribution of Common Co-Occurring, Other Targetable Mutations, and Markers of Immunotherapy Response Across IDH1-/2-Mutated and Wildtype CCA
| Alteration/Marker | IDH1+ iCCA (n = 426) | IDH2+ iCCA (n = 125) | IDHwt iCCA (n = 2516) | P a |
|---|---|---|---|---|
| Most common co-occurring alterations, % | ||||
| TP53 | 12 | 9 | 39 | <.0001 |
| CDKN2A/CDKN2B | 20/16 | 12/9 | 33/23 | <.0001 |
| MTAP | 8 | 6 | 17 | <.0001 |
| Co-occurring targetable alterations, % | ||||
| FGFR2 rearrangements | 1 | 1 | 10 | <.0001 |
| ERBB2 variants/amplifications | <1/2 | 2/1 | 1/4 | .0009 |
| BRAF | 4 | 2 | 5 | .04 |
| Markers of immunotherapy response, % | ||||
| MSI-high | <1 | 0 | 1 | <.009 |
| TMB ≥10 mut/Mb | <1 | 0 | 5 | <.0001 |
| PD-L1–low positive (TPS 1%-49%) | 2 (n = 121) | 17 (n = 35) | 18 (n = 691) | <.001 |
| PD-L1–high positive (TPS ≥50%) | 1 | 9 | 6 | .11 |
Abbreviations: CCA, cholangiocarcinoma; FGFR2, fibroblast growth factor receptor 2; iCCA, intrahepatic cholangiocarcinoma; MSI, microsatellite instability; TMB, tumor mutational burden; TPS, tumor proportion score.
a
P value between IDH1/2+ and IDHwt.