Table 2. Clinical characteristics and EGFR T790M ctDNA status in plasma of 117 patients.

	Total	T790M ctDNA in plasma		p-value
		T790M +ve	T790M −ve
N	117	55	62
Age				1
<=60	66	31	35
>60	51	24	27
Sex				0.1293
Female	71	29	42
Male	46	26	20
Histopathological type				0.1698
Adenocarcinoma	108	53	55
Non-adeno	9	2	7
Clinical stage				0.0677
Recurrent	21	6	15
Stage IV	91	48	43
Stage IIIb	5	1	4
Smoking				0.3918
Yes	29	16	13
No	88	39	49
TKI line of treatment				0.6688
First line	29	15	14
Second line or after	88	40	48
Post TKI PD therapy				0.6467
TKI alone	55	24	31
TKI + chemo	52	25	27
Others	10	6	4