Table 3.
Genomic characteristics of POLE-mutated endometrioid endometrial adenocarcinomas.
| Genomic characteristic |
POLE mutant EECs (n=23) n (%) |
|---|---|
| Median number total mutations (range) | 262 (51–757) |
| Median number non-synonymous mutations (range) | 219 (47–582) |
| Exonuclease domain mutation | |
| p.V411L | 9 (41) |
| p.P286R | 8 (36) |
| p.A456P | 4 (18) |
| p.F367V and p.P476S (1 sample) | 1 (5) |
| p.P436R | 1 (5) |
| MSIsensor score | |
| MSI-high | 2 (9) |
| MSI-indeterminate | 2 (9) |
| MSS | 19 (83) |
| DNA Mismatch repair protein IHC | |
| Proficient | 18 (78) |
| Deficient | 5 (22) |
| MLH1 hypermethylation | 1 |
| MSH6 somatic mutation* | 3 |
| Unexplained** | 1 |
| Germline mutation | |
| None identified | 20(87) |
| No germline testing | 3 (13) |
*
All 3 samples had dual somatic MSH6 mutation.
**
No germline or somatic MMR gene mutation to explain IHC MMR protein deficiency.
MSI, microsatellite; MSI-high, microsatellite unstable; MSS, microsatellite stable; IHC, immunohistochemistry