Table 1. Descriptive characteristics of cases and controls.

	Men				Women
	Cases		Controls		Cases		Controls
Variables	N	%	N	%	N	%	N	%
Country
Romania	63	9.7	109	11.4	32	7.1	51	9.7
Poland	56	8.6	112	11.8	43	6.6	86	16.4
Russia	163	25.4	305	32.0	154	34.3	158	30.2
Czech Republic	366	56.4	426	44.8	220	49.0	229	43.7
Total	648	100	952	100	449	100	524	100
Age (years)
<40	25	4.1	25	2.6	14	3.1	18	3.4
40–49	91	14.0	152	16.0	53	11.8	60	11.5
50–59	227	35.0	320	33.6	122	27.2	153	29.2
60–69	187	28.9	289	30.4	150	33.5	170	32.4
>70	118	18.0	166	17.4	110	24.4	123	23.5
Tumour stage
T-stage
T1	117	18.8			90	20.5
T2	275	44.1			209	47.5
T3	210	33.6			126	28.6
T4	22	3.5			15	3.4
M-stage
M0	486	90.8			363	93.1
M1	49	9.2			27	6.9
N-stage
N0	505	89.7			371	91.2
N1	31	5.5			24	5.9
N2	24	4.3			10	2.4
N3	3	0.5			2	0.5
Histology
(Clear cell) Renal cell carcinoma	538	83.0			370	82.4
Papillary renal cell carcinoma	51	7.9			20	4.5
Other	59	9.1			59	13.1