Table 1.
Clinical and methylation characteristics of the study population at time of first and recurrence surgery
| Feature | N = 32 | No subclass transition (n = 22) | Subclass transition (n = 10) | p value |
|---|---|---|---|---|
| First resection | ||||
| Age at 1st surgery, mean (SD) | 59.4 (11.5) | 59.1 (12.4) | 59.9 (9.9) | 0.87 |
| Gender, n (%) | ||||
| Female | 11 (34.4) | 8 (36.4) | 3 (30.0) | 0.73 |
| Male | 21 (65.6) | 14 (63.6) | 7 (70.0) | |
| Preoperative seizures, n (%) | 15 (46.9) | 10 (45.5) | 5 (50.0) | 0.81 |
| Location, n (%) | ||||
| Frontal | 8 (25.0) | 5 (22.7) | 3 (30.0) | 0.66 |
| Parietal | 17 (53.1) | 11 (50.0) | 6 (60.0) | 0.59 |
| Temporal | 15 (46.9) | 8 (36.4) | 7 (70.0) | 0.08 |
| Occipital | 3 (9.4) | 2 (9.1) | 1 (10.0) | 0.94 |
| Eloquent | 20 (62.5) | 14 (63.6) | 6 (60.0) | 0.84 |
| Side, n (%) | ||||
| Left | 19 (59.4) | 14 (63.6) | 5 (50.0) | 0.47 |
| Right | 13 (40.6) | 8 (36.4) | 5 (50.0) | |
| Preoperative CE volume, [cm3], mean (SD) | 20.5 (22.2) | 13.8 (20.6) | 29.5 (25.1) | 0.40 |
| Preoperative FLAIR volume, [cm3], mean (SD) | 53.9 (45.9) | 33.1 (30.3) | 81.8 (53.9) | 0.18 |
| Extent of 1st resection, n (%) | ||||
| GTR | 20 (62.5) | 17 (77.3) | 3 (30.0) | 0.04 |
| Near GTR | 9 (28.1) | 4 (18.2) | 5 (50.0) | |
| Partial resection | 3 (9.4) | 1 (4.5) | 2 (20.0) | |
| Karnofsky prior 1st line adjuvant therapy, [%], mean (SD) | ||||
| 1st line adjuvant therapy, n (%) | ||||
| None | 4 (12.5) | 3 (13.6) | 1 (10.0) | 0.77 |
| Combined radiochemotherapy | 28 (87.5) | 19 (86.4) | 9 (90.0) | |
| Radiation dosage, [Gy], mean (SD) | 59.6 (2.9) | 60.2 (0.9) | 58.2 (4.9) | 0.09 |
| No. of cycles of Temozolomide, mean (%) | 3.8 (2.4) | 3.9 (2.2) | 3.4 (2.9) | 0.59 |
| Max. TMZ dosage, [mg/m2], mean (SD) | 159.0 (31.4) | 159.2 (30.3) | 158.2 (37.7) | 0.95 |
| Time 1st surgery to adjuvant treatment start, [days], mean (SD) | 27.8 (9.7) | 28.9 (10.1) | 25.1 (8.8) | 0.37 |
| Time end combined treatment to start 1st cycle TMZ, [days], mean (SD) | 23.4 (12.4) | 23.7 (13.9) | 22.0 (4.0) | 0.79 |
| Time 1st to 2nd surgery, [months], mean (SD) | 15.6 (16.7) | 15.4 (17.6) | 16.1 (15.3) | 0.91 |
| Absolute DNA tumor purity, mean (SD) | 0.54 (0.09) | 0.55 (0.09) | 0.52 (0.11) | 0.46 |
| Estimate DNA tumor purity, mean (SD) | 0.80 (0.07) | 0.82 (0.06) | 0.78 (0.08) | 0.20 |
| Re-resection | ||||
| Extent of 2nd resection, n (%) | ||||
| GTR | 12 (37.5) | 11 (50.0) | 1 (10.0) | 0.09 |
| Near GTR | 15 (46.9) | 8 (36.4) | 7 (70.0) | |
| Partial resection | 5 (15.6) | 3 (13.6) | 2 (20.0) | |
| Karnofsky prior 2nd line adjuvant therapy, mean (SD) | 78.4 (14.2) | 80.5 (13.9) | 74.0 (14.3) | 0.24 |
| 2nd line adjuvant therapy, n (%) | ||||
| None | 2 (6.3) | 2 (9.1) | 0 (0.0) | 0.04 |
| Stupp | 11 (34.4) | 7 (31.8) | 4 (40.0) | |
| Radiation + procarbazin/CCNU | 7 (21.9) | 7 (31.8) | 0 (0.0) | |
| Temzolomide | 2 (6.3) | 0 (0.0) | 2 (20.0) | |
| Procarbazin/CCNU | 3 (9.4) | 3 (13.6) | 0 (0.0) | |
| Re-radiation | 1 (3.1) | 0 (0.0) | 1 (10.0) | |
| Experimental | 6 (18.8) | 3 (13.6) | 3 (30.0) | |
| DNA methylation profiling | ||||
| Subclass 1st surgery, n (%) | ||||
| RTK I | 8 (25.0) | 5 (22.7) | 3 (30.0) | 0.77 |
| RTK II | 15 (46.9) | 10 (45.5) | 5 (50.0) | |
| MES | 9 (28.1) | 7 (31.8) | 2 (20.0) | |
| Calibrated score 1st surgery, mean (SD) | 0.95 (0.09) | 0.94 (0.09) | 0.96 (0.07) | 0.57 |
| Family member score 1st surgery, mean (SD) | 0.72 (0.18) | 0.74 (0.19) | 0.70 (0.16) | 0.57 |
| Subclass 2nd surgery, n (%) | ||||
| RTK I | 6 (18.8) | 5 (22.7) | 1 (10.0) | 0.13 |
| RTK II | 12 (37.5) | 10 (45.5) | 2 (20.0) | |
| MES | 14 (43.8) | 7 (31.8) | 7 (70.0) | |
| Calibrated score 2nd surgery, mean (SD) | 0.95 (0.09) | 0.95 (0.08) | 0.95 (0.11) | 0.93 |
| Family member score 2nd surgery, mean (SD) | 0.73 (0.16) | 0.77 (0.16) | 0.66 (0.16) | 0.11 |
P values in bold refer to a significant value below 0.05