Table 2.

Odds ratios (ORs) and their corresponding 95% confidence intervals (CIs) for risk of nasopharyngeal carcinoma (NPC) in association with family history of NPC in first-degree relatives.

	Cases (No=2499)	Controls (No=2576)	Minimally adjusted OR (95% CIs) *	Fully adjusted OR (95% CIs) †
Family history of NPC in first-degree relatives
No	2208	2483	1.0 (reference)	1.0 (reference)
Yes	270	69	4.5 (3.4 to 5.8)	4.6 (3.5 to 6.1)
1 affected	236	63	4.3 (3.2 to 5.7)	4.4 (3.3 to 5.9)
≥2 affected	34	6	6.6 (2.7 to 15.7)	6.7 (2.8 to 16.0)
P for trend			<0.001	<0.001
Affected relatives ‡
Father
No	2421	2543	1.0 (reference)	1.0 (reference)
Yes	72	26	2.9 (1.8 to 4.5)	3.1 (2.0 to 5.0)
Mother
No	2429	2561	1.0 (reference)	1.0 (reference)
Yes	58	11	5.4 (2.8 to 10.4)	5.6 (2.9 to 10.8)
Parent
No	2357	2529	1.0 (reference)	1.0 (reference)
Yes	130	37	3.7 (2.6 to 5.4)	4.0 (2.7 to 5.8)
Brother
No	2332	2478	1.0 (reference)	1.0 (reference)
Yes	113	26	4.7 (3.0 to 7.2)	4.8 (3.1 to 7.4)
Sister
No	2395	2499	1.0 (reference)	1.0 (reference)
Yes	53	10	5.7 (2.9 to 11.3)	5.6 (2.8 to 11.1)
Siblings
No	2283	2466	1.0 (reference)	1.0 (reference)
Yes	159	35	5.0 (3.5 to 7.3)	5.1 (3.5 to 7.4)
1 affected	142	34	4.6 (3.2 to 6.8)	4.7 (3.2 to 6.9)
≥2 affected	17	1	19.1 (2.5 to 144.1)	18.9 (2.5 to 142.8)
P for trend			<0.001	<0.001
Offspring
No	2355	2436	1.0 (reference)	1.0 (reference)
Yes	3	2	1.7 (0.3 to 10.4)	1.6 (0.3 to 9.9)

^*Adjusted for age, sex, residential area, and family size (continuous; see below).

^†Adjusted for age, sex, residential area, family size (see below), education level, current housing type, current occupation, cigarette smoking, tea drinking, and salt-preserved fish consumption in 2000–2002.

^‡In analyses of history of NPC in parents, fathers, or mothers, ORs were not adjusted for family size. In analyses of history of NPC in brothers or sisters, siblings, or offspring, ORs were adjusted for number of brothers, number of sisters, number of siblings, or number of offspring, respectively.