EGFR Mutation Analysis of Circulating Tumor DNA Using an Improved PNA-LNA PCR Clamp Method

Table 4

Characteristics of patients with alteration of the EGFR mutation status after EGFR-TKI treatment.

	Persistent plasma EGFR mutation negative (A)	Conversion of plasma EGFR mutation from positive to negative (B)	Persistent plasma EGFR mutation positive (C)
Total,	5	12	6
Age
Median (range)	68 (55–84)	65.5 (46–87)	66.5 (58–79)
Gender
Female	5 (100)	7 (58.3)	3 (50.0)
Male	0 (0.0)	5 (41.7)	3 (50.0)
Smoking status
Never	4 (80.0)	9 (75.0)	4 (66.6)
Former	1 (20.0)	1 (8.3)	1 (16.7)
Current	0 (0.0)	2 (16.7)	1 (16.7)
ECOG PS
0	3 (60.0)	4 (33.3)	0 (0.0)
1	2 (40.0)	7 (58.3)	5 (83.3)
2	0 (0.0)	1 (8.3)	1 (16.7)
Stage
IIIA	1 (20.0)	1 (8.3)	0 (0.0)
IV	4 (80.0)	11 (91.7)	6 (100)
IV-M1a	4 (100)	4 (36.4)	0 (0.0)
IV-M1b	0 (0.0)	7 (63.6)	6 (100)
Tumor EGFR mutation status
del19	3 (60.0)	8 (66.7)	3 (50.0)
L858R	1 (20.0)	4 (33.3)	3 (50.0)
L861Q	1 (20.0)	0 (0.0)	0 (0.0)