Table 1.

Concordance between tumor and cobas plasma test EGFR status

Cobas tumor test mutation status
Mutation positiveMutation negativeInadequate tissueTotal
Cobas plasma test
Activating mutation
 Mutation positive5501368
 Mutation negative2024347
 Total752416115a
T790M
 Mutation positive211325
 Mutation negative12611285
 Total336215110
Activating mutations (tumor as reference)95% CI
 PPA73% (55/75)(62%–83%)
 Negative percent agreement100% (24/24)(86%–100%)
 Overall percent agreement80% (79/99)(71%–87%)
T790M (tumor as reference)95% CI
 PPA64% (21/33)(45%–80%)
 Negative percent agreement98% (61/62)(91%–100%)
 Overall percent agreement86% (82/95)(78%–93%)

Abbreviation: CI, confidence interval.

  • aFive patients had two activating mutations identified; each activating mutation was counted individually.