Table 1. Characteristics of the study sample (N = 497).

	NSCLC Cases		Non-cancer Control		Total Sample		p§
	n	%	n	%	n	%
Sample size	187	37.63	310	62.37	497	100.00
Gender
Female	73	39.04	134	43.23	212	41.73	0.3588
Male	114	60.96	176	56.77	296	58.27
Age
36-65	81	43.32	127	40.97	216	42.52	0.6073
66-95	106	56.68	183	59.03	292	57.48
Smoking status*
No	84	44.92	218	70.32	309	60.83	<0.0001
Yes	103	55.08	92	29.68	199	39.17

^§The p value was obtained from the chi-square test.

^*Smoking status: No: non-smoker, Yes: current smoker and ever smoker.