Table 2.

Digital PCR detection of EGFR mutations in plasma collected before treatment

PatientTumor tissuePlasmaResponse to TKI treatment if treated with TKI*
CSGE and sequencing analysis,Digital PCR analysis§Digital PCR analysis§
Del19 mutant percentageL858R mutant percentageMutationConcentration (copies/mL)
(A) Mutations detected by digital PCR and by CSGE and sequencing
    Case 8L858RND40L858R3.2PR
    Case 15L858RND19L858R55PD
    Case 20L858RND23L858R3.2
    Case 29L858RND87L858R29
    Case 38L858RND39L858R34,000CR
    Case 39L858RND26L858R9.7PR
    Case 37L858RND5.2NoneND
    Case 11Del1965NDDel1921PR
    Case 13Del1942NDDel19140
    Case 17Del1938NDDel19890
    Case 31Del1968NDDel19200
    Case 40Del1932NDDel1949
(B) Mutations detected by digital PCR (CSGE and sequencing was unsuccessful)
    Case 18Failed563.9Del1922
    Case 26FailedND62L858R8,300PR
    Case 30FailedND64L858R52
    Case 34FailedND45L858R500
(B) Mutations detected by digital PCR but not by CSGE and sequencing
    Case 3Wild-type onlyND3.4NoneND
    Case 4Wild-type onlyND2.0NoneND
    Case 19Wild-type only4.6NDNoneND
(C) No mutation detected in tumor
    Case 5Wild-type onlyNDNDNoneND
    Case 6Wild-type onlyNDNDNoneND
    Case 10Wild-type onlyNDNDNoneND
    Case 14Wild-type onlyNDNDNoneND
    Case 16Wild-type onlyNDNDNoneND
    Case 21Wild-type onlyNDNDNoneND
    Case 22Wild-type onlyNDNDNoneND
    Case 23Wild-type onlyNDNDNoneND
    Case 24Wild-type onlyNDNDNoneND
    Case 25Wild-type onlyNDNDNoneND
    Case 27Wild-type onlyNDNDNoneND
    Case 28Wild-type onlyNDNDNoneND
    Case 32Wild-type onlyNDNDNoneND
    Case 33FailedNDNDNoneND
    Case 35FailedNDNDNoneND
    Case 36Wild-type onlyNDNDNoneND
  • * Clinical response was defined by Response Evaluation Criteria in Solid Tumors. CR, complete response; PR, partial response; SD, stable disease; PD, progressive disease.

  • Del19 denotes deletion mutation in exon 19 of the EGFR gene. All L858R mutations are 2573T>G.

  • Cases that PCR amplification is failed are denoted as “Failed.”.

  • § All numerical figures are correct to two significant figures.