Table 2.
Incidence of and Adjusted Hazard Ratios, for Nasopharyngeal Carcinoma, by Family History, Anti-Epstein-Barr Virus Seromarker Status, and Cigarette Smoking at Study Entry, Taiwan, 1984–2008
| Variable | No. of Participants | Person-Years | No. of Nasopharyngeal Carcinoma Cases | Cumulative Incidencea | Adjusted Hazard Ratiob | 95% Confidence Interval | Adjusted Hazard Ratioc | 95% Confidence Interval |
| Family history | ||||||||
| Community cohort | 9,622 | 1,85,587.3 | 33 | 17.8 | 1.0 | Referent | 1.0 | Referent |
| Multiplex family cohort | 1,019 | 8,060.8 | 10 | 124.1 | 11.7 | 4.6, 29.9 | 6.8 | 2.3, 20.1 |
| Anti-EBV VCA IgAd | ||||||||
| Negative | 10,032 | 1,87,921.4 | 32 | 17.0 | 1.0 | Referent | ||
| Positive | 293 | 3,395.2 | 7 | 206.2 | 11.6 | 4.7, 28.6 | ||
| Anti-EBV deoxyribonucleasee | ||||||||
| Negative | 9,328 | 1,70,610.8 | 30 | 17.6 | 1.0 | Referent | ||
| Positive | 1,243 | 21,836.7 | 12 | 55.0 | 3.4 | 1.7, 6.6 | ||
| Combination of VCA IgA and deoxyribonucleasef | ||||||||
| Both negative | 8,880 | 1,67,090.5 | 24 | 14.4 | 1.0 | Referent | 1.0 | Referent |
| Either one positive | 1,373 | 23,248.6 | 12 | 51.6 | 3.5 | 1.7, 7.1 | 2.8 | 1.3, 6.0 |
| Both positive | 70 | 938.6 | 3 | 319.6 | 23.4 | 6.9, 79.1 | 15.1 | 4.2, 54.1 |
| Cumulative cigarette smoking, pack-yearsg | ||||||||
| 0 | 3,728 | 69,212.0 | 13 | 18.8 | 1.0 | Referent | 1.0 | Referent |
| <30 | 4,355 | 82,033.8 | 14 | 17.1 | ||||
| ≥30 | 2,208 | 36,085.3 | 14 | 38.8 | 2.3 | 1.1, 5.0 | 1.8 | 0.8, 4.1 |
Abbreviations: EBV, Epstein-Barr virus; IgA, immunoglobulin A; VCA, viral capsid antigen.
Per 100,000 person-years.
Adjusted for age (continuous), ethnicity (Fukkinese or non-Fukkinese), and years of schooling (0–6 years or ≥7 years).
Model included age (continuous), ethnicity (Fukkinese or non-Fukkinese), years of schooling (0–6 years or ≥7 years), family history, cumulative cigarette smoking, and combination of anti-EBV VCA IgA tested by immunofluorescence assay and anti-EBV deoxyribonuclease.
Data for anti-EBV VCA IgA tests were not available for 316 participants, including 4 nasopharyngeal carcinoma cases.
Data for anti-EBV deoxyribonuclease tests were not available for 70 participants, including 1 nasopharyngeal carcinoma case.
Data for the combination of VCA IgA and deoxyribonuclease were not available for 318 participants, including 4 nasopharyngeal carcinoma cases.
Data for cumulative cigarette smoking were not available for 350 participants, including 2 nasopharyngeal carcinoma cases.