Table 1. Sociodemographics, Lifestyle, and Viral Status of 319 Nasopharyngeal Carcinoma Cases and 319 Matched Controls.
| Characteristic/Category | Cases | Controls | P-value a | Adj. OR (95%CI) |
|---|---|---|---|---|
| n (%) | n (%) | |||
| Gender | ||||
| Male | 220 (69.0) | 220 (69.0) | 1.00 | |
| Female | 99 (31.0) | 99 (31.0) | ||
| Age (mean ± SD), years | 45.6 ± 11.6 | 46.0 ± 11.7 | 0.62 | |
| Age, years | ||||
| <40 | 103 (32.3) | 102 (32.0) | 1.00 | |
| 40–49 | 93 (29.1) | 94 (29.5) | ||
| 50–59 | 77 (24.1) | 74 (23.2) | ||
| 60–69 | 42 (13.2) | 45 (14.0) | ||
| ≧70 | 4 (1.3) | 4 (1.3) | ||
| Ethnicity | ||||
| Mainlander d | 34 (9.2) | 68 (21.2) | <0.0001 | 1.00 (Ref.) |
| Fukienese | 305 (82.2) | 234 (72.9) | 2.56 (1.57–4.18) b | |
| Hakka | 32 (8.6) | 19 (5.9) | 3.13 (1.52–6.44) b | |
| Educational level | ||||
| Junior high school or below | 189 (59.3) | 160 (50.2) | 0.02 | 1.00 (Ref.) |
| Senior high school or above | 130 (40.7) | 159 (49.8) | 0.59 (0.41–0.86) c | |
| Smoking habit | ||||
| 0–25 years | 241 (75.6) | 256 (80.3) | 0.15 | 1.00 (Ref.) |
| Smoker ≧25 years | 78 (24.4) | 63 (19.7) | 1.64 (1.01–2.68) c | |
| Alcohol drinking habit | ||||
| 0–10 years | 250 (78.4) | 247 (77.7) | 0.83 | 1.00 (Ref.) |
| ≧10 years | 69 (21.6) | 71 (22.3) | 0.99 (0.66–1.47) c | |
| Formaldehyde exposure | ||||
| No | 260 (81.5) | 278 (81.2) | 0.05 | 1.00 (Ref.) |
| Yes | 59 (18.5) | 41 (12.8) | 1.61 (1.02–2.53) c | |
| Wood dust exposure | ||||
| No | 276 (86.5) | 293 (91.9) | 0.03 | 1.00 (Ref.) |
| Yes | 43 (13.5) | 26 (8.1) | 1.83 (1.06–3.17) c | |
| Nitrosamine from foods e | ||||
| Q1 (low) | 64 (20.1) | 80 (25.1) | 0.18 | 1.00 (Ref.) |
| Q2 | 71 (22.3) | 81 (25.4) | 1.23 (0.76–1.99) c | |
| Q3 | 84 (26.3) | 78 (24.4) | 1.63 (0.98–2.70) c | |
| Q4 (high) | 100 (31.3) | 80 (25.1) | 1.78 (1.11–2.88) c | |
| NPC family history | ||||
| No | 296 (93.1) | 313 (99.1) | 0.0001 | 1.00 (Ref.) |
| Yes | 22 (6.9) | 3 (0.9) | 6.96 (2.07–23.44) c | |
| Anti-EBV seropositive | ||||
| No | 2 (0.6) | 216 (68.8) | <0.0001 | 1.00 (Ref.) |
| Yes | 313 (99.4) | 98 (31.2) | 243.60 (32.07->999) c |
Adj., adjusted; CI, confidence interval; OR, odds ratio; Ref., referent, SD, standard deviation.
a Significant difference between cases and controls were assessed using a Chi-square test for categorical variables and Student’s t-test for continuous variables.
b Adjusted for age.
c Adjusted for age, and ethnicity.
d Those who moved to Taiwan in the past few decades.
e Nitrosamine index was calculated from food consumption. Index values were categorized into quartiles based on the distribution among the controls, and those in the lowest quartile were used as the referent group.