ABO blood group is a predictor of survival in patients with laryngeal cancer

Table 2 Univariate prognostic analysis for overall survival (OS) rates of 1260 patients with laryngeal cancer

Variable	No. of patients	OS rate (%)		χ ²	P
Variable	No. of patients	5-year	10-year	χ ²	P
Sex				6.079	0.014
Men	1226	70.0	59.7
Women	34	85.3	85.3
Age (years)^a				35.892	<0.001
≤61	661	76.0	68.7
>61	599	64.4	51.5
Smoking index^b				8.322	0.004
≤600	659	73.2	64.1
>600	601	67.4	56.2
Alcohol consumption				4.933	0.026
No	808	72.3	62.5
Yes	452	67.2	56.6
Differentiation				27.775	<0.001
Well	600	76.8	65.7
Moderate	481	68.5	58.4
Poor	179	54.6	48.1
Primary site				31.102	<0.001
Glottic	885	74.8	64.8
Supraglottic	331	58.6	48.7
Subglottic	44	72.7	56.2
Blood group				11.637	0.009
A	347	76.0	67.5
B	332	69.8	58.4
AB	101	73.1	65.6
O	480	66.4	55.5
T category				101.754	<0.001
T1	434	84.2	72.0
T2	382	74.3	63.0
T3	244	59.4	51.4
T4	200	46.8	41.1
N category				119.722	<0.001
N0	1021	76.9	66.1
N+	239	43.0	35.4
UICC stage				127.473	<0.001
I	421	85.4	73.5
II	326	77.2	65.3
III	242	62.4	52.6
IV	271	46.3	41.4

UICC Union for International Cancer Control
^aPatients were divided into two groups according to the median age
^bSmoking index was defined as the number of cigarettes smoked per day × the total smoking duration (years)