Table 2.

Demographic characteristics in the cases and controls

	Variables	Cases (n = 317) (%)	Controls (n = 317)	P
Sex	Male	242	236
	Female	75	81
	Age (Mean ± SD)	63.35 ± 12.95	64.13 ± 12.38	0.443
Smoking	Non smokers	168
	Smokers	149
Grade	I	43
	II	108
	III	155
	Mixed	11
Stage	Superficial	138
	Invasive	179
Event	Recurrence/non recurrence	71/54
	Death/live	38/87