Table 1.

Incidence of EGFR Mutations by Cigarette Smoking History

Smoking History	Stage I-IIIA			Stage IIIB/IV			All Stages				P
	No. with Mutations	Total No. of Tumors	%	No. with Mutations	Total No. of Tumors	%	No. with Mutations	Total No. of Tumors	%	95% CI
Never	131	228	57	171	352	49	302	580	52	48 to 56	< .001 χ2(df = 2) = 314
Former	83	714	12	98	504	19	181	1,218	15	13 to 17
Current	4	143	3	16	201	8	20	344	6	4 to 9