Table 2.

Main characteristics of patients without/with recurrence and p-values of the chi-square test.

Risk Factors	Classes	n	%	Without Recurrence	With Recurrence	% With Recurrence	p (Chi2)
Age (years)	<60	63	39.4%	30	33	52%	0.720
	60–69	47	29.4%	19	28	60%
	≥70	50	31.3%	21	29	58%
Smoking status	Current	79	49.4%	33	46	58%	0.250
	Former	69	43.1%	29	40	58%
	Never	12	7.5%	8	4	33%
Tumor aggressiveness	Low	41	25.6%	15	26	63%	0.284
	High	119	74.4%	55	64	54%
MPO	0	154	96.3%	67	87	56%	0.753
	1	6	3.8%	3	3	50%
SULT	0	153	95.6%	66	87	57%	0.465
	1	7	4.4%	4	3	43%
GSTM1	0	57	35.6%	26	31	54%	0.724
	1	103	64.4%	44	59	57%
GSTP1	0	76	47.5%	30	46	61%	0.300
	1	84	52.5%	40	44	52%
GSTT1	0	125	78.1%	53	72	58%	0.515
	1	35	21.9%	17	18	51%
MnSOD	0	106	66.3%	43	63	59%	0.255
	1	54	33.8%	27	27	50%
COMT	0	48	30.0%	22	26	54%	0.728
	1	112	70.0%	48	64	57%
XRCC1	0	72	45.0%	30	42	58%	0.631
	1	88	55.0%	40	48	55%
XPD	0	58	36.3%	23	35	60%	0.431
	1	102	63.8%	47	55	54%
XRCC3	0	72	45.0%	29	43	60%	0.423
	1	88	55.0%	41	47	53%
NQO1	0	151	94.4%	62	89	59%	0.005
	1	9	5.6%	8	1	11%
NAT1	0	110	68.8%	48	62	56%	0.966
	1	50	31.3%	22	28	56%
NAT2	0	64	40.0%	26	38	59%	0.515
	1	96	60.0%	44	52	54%
DNA Adducts	≤5.6	123	76.9%	60	63	51%	0.019
	>5.6	37	23.1%	10	27	73%
Exposure to PAH	Never	100	62.5%	44	56	56%	0.934
	Ever	60	37.5%	26	34	57%
Exposure to aromatic amines	Never	148	92.5%	66	82	55%	0.449
	Ever	12	7.5%	4	8	67%