Table 2. EZH2 expression and H3K27me3/me2 score according to EZH2 alteration status.
| Total | Non-altered | Altered (mutation or gain)a | Mutation-onlya | Gain-onlya | Mutation+gaina | |
|---|---|---|---|---|---|---|
| Patients, n | 159 | 100 | 59b | 34 | 13 | 10 |
| IHC data usable, EZH2 score/H3K27 score | 55/63 | 34/44 | 21/19 | 10/10 | 7/7 | 4/2 |
| EZH2 mRNA level, median (range) | 12.54 (11.51–13.36) | 12.42 (11.51–13.36) | 12.70 (11.95–13.70)*** | 12.61 (11.95–13.11)*** | 12.87 (11.98–13.70)** | 12.92 (12.64–13.19)*** |
| EZH2 IHC (%), median (range) | 30 (5–80) | 30 (5–80) | 50 (20–80)*** | 45 (20–70)ns | 70 (40–80)*** | 50 (30–80)NT |
| H3K27me2 IHC (%), median (range) | 100 (2–100) | 100 (30–100) | 70 (2–100)*** | 30 (5–100)*** | 100 (100–100)ns | 10 (2–50)NT |
| H3K27me3 IHC (%), median (range) | 70 (1–90) | 70 (1–90) | 70 (50–90)ns | 65 (50–90)ns | 70 (50–90)ns | 70 (50–75)NT |
| me3/me2 score, median (range) | −0.32 (−1.86; 2.74) | −0.46 (−1.86; −0.14) | (−0.87; 2.74)** | 1.24 (0; 2.22)*** | −0.46 (−0.87; −0.14)ns | 1.62 (0.50; 2.74)NT |
NTThe differences between non-altered patients and the subgroup of patients with both mutation and gain alterations were not tested (NT) due to the small sample size.
nsNot significant (no trend was observed, all P-values were >0.1). **0.001<P<0.01, ***P<0.001. Expression levels between groups were compared using the Mann–Whitney test.
a
All subgroups were compared to non-altered patients (no gain or mutation at the EZH2 locus). Expression levels between groups were compared using Mann–Whitney test.
b
Two patients were mutated but had no SNP-array analysis performed. These patients were considered to be ‘altered' but could not be included in the ‘mutation-only' subgroup nor in the ‘mutation+gain' subgroup.