Earlier onset and multiple primaries in familial as opposed to sporadic esophageal cancer

Table 2 Difference in the prevalence of multiple primary esophageal squamous cell carcinoma/gastric cardia adenocarcinoma in patients with esophageal squamous cell carcinoma with and without a family history of the cancer

Classification	Family history	n (% of multiple primary cancer)	Total	χ2	aP
Overall		72 (2.8)	2542
	Negative family history	30 (1.7)	1776
	Positive family history	42 (5.5)	766	27.80	0.000b
Sex
Male	Negative family history	20 (1.7)	1176
	Positive family history	27 (5.0)	537	15.30	0.000b
Female	Negative family history	10 (1.7)	600
	Positive family history	15 (6.6)	229	13.52	0.000b
Age
≥ 55 yr	Negative family history	23 (2.6)	877
	Positive family history	15 (5.0)	303	3.29	0.070
< 55 yr	Negative family history	7 (0.8)	899
	Positive family history	27 (5.8)	463	32.06	0.000b
Tobacco
Smoker	Negative family history	20 (1.9)	1037
	Positive family history	1.8 (3.7)	484	3.63	0.060
Nonsmoker	Negative family history	10 (1.4)	739
	Positive family history	24 (8.5)	282	32.48	0.000b
Alcohol
Drinker	Negative family history	16 (2.8)	576
	Positive family history	13 (4.5)	286	1.84	0.230
Nondrinker	Negative family history	14 (1.2)	1200
	Positive family history	29 (6.0)	480	32.67	0.000b
TNM
Tis,1N0M0	Negative family history	2 (3.0)	66
	Positive family history	2 (5.9)	34	0.48	0.480
T2,3N0M0	Negative family history	8 (0.8)	983
	Positive family history	20 (4.7)	422	23.29	0.000b
T2,3,4N1M0	Negative family history	20 (2.8)	727
	Positive family history	20 (6.5)	310	8.03	0.010b

Positive family vs negative family, ^aP < 0.05,

^bP < 0.01.