Familial tendency and risk of nasopharyngeal carcinoma in taiwan: effects of covariates on risk

Abstract

In the present study, the authors compared the long-term risk of nasopharyngeal carcinoma (NPC) of male participants in an NPC multiplex family cohort with that of controls in a community cohort in Taiwan after adjustment for anti-Epstein-Barr virus (EBV) seromarkers and cigarette smoking. A total of 43 incident NPC cases were identified from the 1,019 males in the NPC multiplex family cohort and the 9,622 males in the community cohort, for a total of 8,061 person-years and 185,587 person-years, respectively. The adjusted hazard ratio was 6.8 (95% confidence interval (CI): 2.3, 20.1) for the multiplex family cohort compared with the community cohort. In the evaluation of anti-EBV viral capsid antigen immunoglobulin A and anti-EBV deoxyribonuclease, the adjusted hazard ratios were 2.8 (95% CI: 1.3, 6.0) and 15.1 (95% CI: 4.2, 54.1) for those positive for 1 EBV seromarker and positive for both seromarkers, respectively, compared with those negative for both EBV seromarkers. The adjusted hazard ratio was 31.0 (95% CI: 9.7, 98.7) for participants who reported a family history of NPC and who were anti-EBV-seropositive compared with individuals without such a history who were anti-EBV-seronegative. The findings suggest that both family history of NPC and anti-EBV seropositivity are important determinants of subsequent NPC risk and that the effect of family history on NPC risk cannot be fully explained by mediation through EBV serologic responses.

Figure 1.

Cumulative incidence of nasopharyngeal carcinoma during follow-up among 10,641 males in Taiwan by A) study cohort (solid line: multiplex family cohort; dashed line: community cohort), B) anti-Epstein-Barr virus seromarkers (solid line: seropositive for anti-Epstein-Barr virus viral capsid antigen immunoglobulin A, anti–Epstein-Barr virus deoxyribonuclease, or both; dashed line: seronegative for both seromarkers), and C) cumulative pack-years of cigarette smoking (solid line: cumulative cigarette smoking ≥30 pack-years; dashed line: cumulative cigarette smoking <30 pack-years; dotted line: never smokers). Log-rank test statistics were 37.80 (P < 0.001), 23.49 (P < 0.001), and 5.71 (P = 0.0576) for A, B, and C, respectively.