Table 2. Summary of Univariable and Multivariable Subgroup Analyses in Patients Who Received Chemotherapya.
Molecular subgroup | Univariable | Multivariableb | ||||
---|---|---|---|---|---|---|
HR of uMGMT vs mMGMT (95% CI) | P value | P value for interaction with treatmentb | Adjusted HR of uMGMT vs mMGMT (95% CI) | P value | P value for interaction with treatment (adjusted)c | |
Progression-free survival | ||||||
All cases | 2.29 (1.66-3.17) | <.001 | .004 | 1.95 (1.39-2.75) | <.001d | .004 |
IDH–wild type | 1.95 (1.15-3.30) | .01 | .004 | 2.15 (1.26-3.66) | .005d | <.001 |
IDH-mutant and non-codeleted | 1.19 (0.67-2.12) | .56 | .41 | NRe | NRe | .94 |
IDH-mutant and codeleted | 2.54 (1.24-5.20) | .01 | .39 | 2.99 (1.44-6.21) | .003d | .59 |
Overall survival | ||||||
All cases | 2.30 (1.57-3.37) | <.001 | .003 | 1.65 (1.11-2.46) | .01d | .01 |
IDH–wild type | 1.83 (1.06-3.15) | .03 | .12 | 1.69 (0.98-2.91) | .06 | .02 |
IDH-mutant and non-codeleted | 1.07 (0.54-2.12) | .85 | .32 | NRe | NRe | .70 |
IDH-mutant and codeleted | 2.40 (0.81-7.17) | .12 | .21 | 4.21 (1.25-14.2) | .02d | .26 |
Abbreviations: HR, hazard ratio; mMGMT, methylated MGMT promoter; NR, not reported; uMGMT, unmethylated MGMT promoter.
Summary statistics are provided from separate univariable and multivariable analyses in patients who received alkylating chemotherapy and stratified analyses by molecular subgroups. Full univariable and multivariable analyses are included in eTables 6, 7, 8, 9, 10, 11, 12, and 13 in Supplement 1. Multiple hypothesis testing in molecular subgroups was accounted for in the multivariable analyses of progression-free and overall survival.
Variables included in the analysis were age, sex, molecular class, grade, chemotherapy, and radiotherapy. Variables that approached significance on univariable analysis, using P < .15 as a threshold, were included in the multivariable analyses.
Interaction between MGMT promoter status and chemotherapy was derived from analysis for all patients stratified by the chemotherapy and no chemotherapy groups (Figure 1; eTable 17 in Supplement 1).
Significant after adjusting for multiple hypothesis testing.
Variables that were not significant on univariable analysis were not included in the multivariable analysis and therefore not reported.