Table 3.

Relationship Between Patients’ Background and C797S Status at Re-bx

Factors	C797S+ (Range)		C797S− (Range)		p Value
EGFR T790M
Positive	11	78.6%	3	21.4%
Negative	0	0.0%	5	100%	0.01
EGFR common mutation
Del19	7	58.3%	5	41.7%
L858R	4	57.1%	3	42.9%	NS
CN gain
EGFR	6	66.7%	3	33.3%	NS
MET	4	66.7%	2	33.3%	NS
Cell cycle	2	40.0%	3	60.0%	NS
Age
Median	66	(42–82)	68	(60–84)	NS
Sex
Male	3	42.9%	4	57.1%
Female	8	66.7%	4	33.3%	NS
TKI durations (mo)
Osimertinib	19.8	(11.1–29.1)	18.35	(8.8–23.7)	NS
Before osimertinib	19.4	(7.6–46)	25.25	(24.2–35.4)	NS
TKI used
1	7	63.6%	4	36.4%
2<	4	50.0%	4	50.0%	NS
Number of other mutations
Tissue at re-biopsy	4	(0–9)	3.5	(1–8)	NS
ccfDNA after re-biopsy	4	(2–9)	5	(2–17)	NS

Note: Including G796S and L792V.

ccfDNA, circulating cell-free DNA; CN, copy number; Del19, exon 19 deletion; mut, mutation; NS, not significant; TKI, tyrosine kinase inhibitor.