Table 2.

MS sequencing results from the nine tumor samples that showed a mismatch between immunohistochemical staining and direct DNA sequencing

(A) EGFR mutant status from IHC, direct DNA sequencing, and MS sequencing
No.IHCDirect seqMS
Exon 19 deletions
    CL182WtDelWt
    CL193WtWtWt
    CL472WtFailedWt
    CL508DelWtDel
    CL720DelWtDel
    CL736WtDel (E746_A750)Del
    CL742WtDelWt
    CL761WtWtWt
    CL781WtWtDel
L858R mutations
    CL182L858RT847AFailed
    CL193WtL858RWt
    CL472L858RWtFailed
    CL508WtFailedWt
    CL720WtL858RWt
    CL736WtWtWt
    CL742WtWtWt
    CL761L858RWtFailed
    CL781WtL858RWt
(B) Correlation of MS sequencing to detect EGFR mutation with IHC and direct DNA sequencing
Correlative no.
Exon 19 del
L858R
%Correlation
IHC/MS seq7/96/6 (3 MS seq failed)87
Direct seq/MS seq4/92/6 (3 MS seq failed)40
  • Abbreviation: seq, sequencing.