Genetic diagnostic features after failure of initial treatment with epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors among non-small-cell lung cancer patients harboring EGFR mutations

Table 7 Background characteristics on patients harboring the T790M substitution through liquid biopsy (n = 58)

Variable	T790M mutation
Variable	Positive (n = 11)	Negative (n = 47)	Total
Original mutation
Absent	1	38	39
Present	10	9	19
Bone metastases
Absent	1	39	40
Present	10	8	18
Enlargement of Tumor size
< 12 mm	7	7	14
12 mm ≤	4	40	44
Brain metastases
Absent	4	38	42
Present	7	9	16
Detection of New tumor lesion
< 4	4	38	42
4 ≤	7	9	16
Detection of New metastatic organ
0	6	36	42
1	2	7	9
2	0	3	3
3	1	1	2
4	2	0	2
New minor site metastases
Absent	8	45	53
Present	3	2	5
Hepatic metastases
Absent	8	44	52
Present	3	3	6
Minor site metastases
Absent	8	44	52
Present	3	3	6
Mutation site at initial diagnosis
Exon19 Deletion	4	41	45
L858R	7	6	13
New hepatic metastases
Absent	9	45	54
Present	2	2	4

Abbreviations: n number, minor site metastases; metastases of skin, kidney, ascites, lymphangiosis carcinomatosa, adrenal organ or others,

ISSN: 1471-2407