Table I.

Distribution of selected characteristics.

Variable	Patients (n=436)		Controls ( n=496)		P-valuea
	n	%	n	%
Age (years)					0.536
≤40	23	5.3	18	3.6
41–50	50	11.5	64	12.9
51–60	132	30.3	166	33.5
61–70	160	36.7	178	35.9
>70	71	16.3	70	14.1
Metastasis at diagnosis
Stage I	131	30.0
Stage II	162	37.2
Stage III	90	20.6
Stage IV	53	12.2
Histological differentiation
Low	56	12.8
Intermediate	166	38.1
High	214	49.1

^aTwo-sided χ² test.