[Mortality trend in nasopharynx cancer in Chinese resident from 1987 to 2015].

To analyze epidemical features, distribution and time trend for nasopharynx cancer deaths in China from 1987 to 2015.
 Methods: Negative binomial regression model was used to explore population-level risk factors for nasopharynx cancer deaths and a joinpoint regression model was used to estimate annual changes in nasopharynx cancer mortality in various populations.
 Results: A falling trend in age-standardized nasopharynx cancer mortality rates was observed among Chinese residents with the average annual percent change (AAPC) at -2.97% among urban female residents and -2.60% among rural female residents (P<0.05), -2.01% among urban male residents, and -1.68% among rural male residents (P<0.05), respectively. It decreased yearly for urban male aged over 85 years with AAPC at -1.54% and the age-specific mortality rates decreased yearly for the urban female aged over 85 years with AAPC at -0.60%, the age-specific mortality rates decreased yearly for rural male residents aged more than 65 years with AAPC at -0.56% and for rural female residents aged more than 85 with AAPC at 1.17%, with no significant difference (P<0.05). The nasopharynx cancer deaths risks were higher in urban residents than those in rural residents (OR=1.11, P<0.01), and they were also higher in male residents than those in female residents (OR=2.34, P<0.01). A 5-year increment in age was associated with a 23% increase in nasopharynx cancer mortality (OR=1.23, P<0.01) and a one year increment in calendar year was related to a 2% decrease in mortality (OR=0.98, P<0.01). 
 Conclusion: There was a significant gender and age difference in a decreased trend of nasopharynx cancer mortality among Chinese residents in a long period; no increased trend was observed in the overall populations over 85 years old.