Cancer patterns in nasopharyngeal carcinoma multiplex families over 15 years.

BACKGROUND: Genetic and environmental factors are important determinants of nasopharyngeal carcinoma (NPC). NPC is associated with Epstein-Barr virus (EBV) infection. Studies have reported familial aggregation of NPC, but evidence has been mixed for elevated rates of cancers other than NPC. METHODS: The authors reassessed their previous evaluation of familial aggregation of cancer in 348 high-risk Taiwanese multiplex families with 2 or more NPC cases enrolled between 1980 and 2003. Participants were linked to the Taiwan National Cancer Registry and National Death Registry to identify cancers. RESULTS: In all, 2590 individuals contributed 37,959 person-years over an average of 15 years of follow-up; 314 incident cancers were identified. The authors computed multiple primary standardized incidence ratios (MP-SIRs) to evaluate the overall risk and the risk of infection-associated, EBV-associated, and individual cancers. The overall MP-SIR was 1.24 (95% confidence interval [CI], 1.10-1.38). The exclusion of excess NPC risk led to an overall MP-SIR of 1.11 (95% CI, 0.98-1.25). Similarly, the risk of cancers associated with infectious agents was driven by the excess in NPC, and its exclusion led to an MP-SIR of 1.22 (95% CI, 0.99-1.48) for infection-associated cancers and to an MP-SIR of 1.18 (95% CI, 0.72-1.82) for EBV-associated cancers. The authors observed a significant excess of second cancers among NPC cases (oral cancer, mouth cancer, tongue cancer, gum cancer, nasal cavity cancer, bone cancer, and non-Hodgkin lymphoma). CONCLUSIONS: This reassessment of the largest NPC multiplex family study confirms the presence of NPC coaggregation within families in Taiwan but does not provide evidence for a broader familial syndrome involving NPC and other tumors. Among NPC cases, elevated rates of secondary cancers, mostly at the, head and neck and hematopoietic cancers suggest radiation treatment effects on subsequent cancer risk.

Lifetime risk of distinct upper aerodigestive tract cancers and consumption of alcohol, betel and cigarette.

The cancer of upper aerodigestive tract (UADT) is a common cancers in the world. However, its lifetime risk by consumption of alcohol, betel and cigarettes remain to be elucidated. This study aimed to estimate lifetime risk of distinct UADT cancers and assess their associations with alcohol, betel and cigarette consumption. Three cohorts of 25,611 men were enrolled in 1982-1992 in Taiwan. The history of alcohol, betel and cigarette consumption was enquired through questionnaire interview. Newly developed UADT cancers were ascertained through computerized linkage with national cancer registry profile. Lifetime (30-80 years old) risk and multivariate-adjusted hazard ratio (HRadj) of distinct UADT cancers by alcohol, betel and cigarette consumption were estimated. A total of 269 pathologically confirmed cases of UADT cancers were newly-diagnosed during 472,096 person-years of follow-up. The lifetime risk of UADT cancer was 9.42 and 1.65% for betel chewers and nonchewers, 3.22 and 1.21% for cigarette smokers and nonsmokers and 4.77 and 1.85% for alcohol drinkers and nondrinkers. The HRadj (95% confidence interval) of developing UADT cancer was 3.36 (2.51-4.49), 2.02 (1.43-2.84), 1.90 (1.46-2.49), respectively, for the consumption of betel, cigarette and alcohol. Alcohol, betel and cigarette had different effect on cancers at various anatomical sites of UADT. The cancer risk from the mouth, pharynx, esophagus to larynx increased for alcohol and cigarette consumption, but decreased for betel consumption. Alcohol, betel and cigarette consumption are independent risk predictors for distinct UADT cancers.