Table 1. Frequency distribution of selected variables of the PCa cases and controls.

Variables	Cases (n=662)		Controls (n=716)		Pa
	n	%	n	%
Age (year) (mean±s.d.)	71.5±8.0		71.5±7.0		0.829
≤71	308	46.5	360	50.3	0.164
>71	354	53.5	356	49.7
Smoking status
Never	277	41.8	350	48.9	0.009
Ever	385	58.2	366	51.1
Pack-years of smoking
0	277	41.8	350	48.9	<0.001
0–32	153	23.1	181	25.3
>32	232	35.1	185	25.8
Drinking status
No	468	70.7	541	75.6	0.042
Yes	194	29.3	175	24.4
Family history of cancer
No	493	74.5	607	84.8	<0.001
Yes	169	25.5	109	15.2
Clinical stage
Localized	529	79.9
Advanced	133	20.1
Gleason score
<7	230	34.7
=7	219	33.1
>7	213	32.2
PSA (ng ml−1)
≤20	294	44.4
>20	368	55.6

Abbreviations: PCa, prostate cancer; PSA, prostate-specific antigen.

^at-test for age distributions between the cases and controls; two-sided χ² test for others selected variables between the cases and controls.