Table 5. Multivariate analysis of risk factors associated with nasopharyngeal carcinoma.
| Dietary intake | All subjects | Anti-EBV-seropositive subjects | ||
| Odds ratio (95% confidence interval)+ | P value | Odds ratio (95% confidence interval)+ | P value | |
| Fresh fish (times/wk) | ||||
| ≤2 | 1.00 (referent) | 1.00 (referent) | ||
| 2–6 | 0.97 (0.63–1.48) | 0.87 | 0.80 (0.42–1.55) | 0.51 |
| >6 | 0.58 (0.39–0.86) | 0.01 | 0.50 (0.27–0.92) | 0.03 |
| P for trend | 0.01 | 0.02 | ||
| Green tea (times/wk) | ||||
| 0 | 1.00 (referent) | 1.00 (referent) | ||
| <1 | 0.55 (0.32–0.94) | 0.03 | 0.44 (0.21–0.96) | 0.04 |
| ≥1 | 0.66 (0.44–1.00) | 0.05 | 0.43 (0.24–0.78) | 0.01 |
| P for trend | 0.02 | 0.003 | ||
| Coffee (times/wk) | ||||
| 0 | 1.00 (referent) | 1.00 (referent) | ||
| <0.5 | 0.80 (0.53–1.19) | 0.27 | 0.61 (0.33–1.11) | 0.10 |
| ≥0.5 | 0.61 (0.40–0.94) | 0.02 | 0.55 (0.29–1.04) | 0.07 |
| P for trend | 0.02 | 0.05 | ||
| Vitamin A from plant source (IU/day) | ||||
| T1 (< = 11670) | 1.00 (referent) | 1.00 (referent) | ||
| T2 (11670–16810) | 0.73 (0.49–1.08) | 0.11 | 0.65 (0.36–1.18) | 0.16 |
| T3 (>16810) | 0.65 (0.43–0.99) | 0.05 | 0.57 (0.30–1.08) | 0.08 |
| P for trend | 0.04 | 0.07 | ||
+
Adjusted for age, gender, ethnicity, educational level, NPC family history, total calories intake, years of cigarette smoking, and exposures to formaldehyde and wood dust.
Sample size in categories varies by available data.