Trend in mortality from thyroid cancer among residents in Dalian city,2005-2014

Objective To investigate the trend of deaths of thyroid cancer (TC) among residents in Dalian city of Liaoning province from 2005 to 2014 and to provide evidences for the control of TC.Methods Data on TC mortality among residents in Dalian from 2005 to 2014 were collected and analyzed;crude death rate (CDR),age-adjusted mortality rate (AAM),constituent ratio for tumor death (CRTD),and annual percent change (APC) were calculated.Results From 2005 to 2014,the CDR fluctuated between 0.60/100 000 and 1.09/100 000 and the change in CDR was not obvious (χ²=6.59,P<0.05),with an APC% of -2.47 (t=-1.08,P<0.05);whereas,the AAM fluctuated between 0.27/100 000 and 0.62/100 000 and decreased obviously (χ²=9.00,P<0.05),with an APC% of -5.82 (t=-2.59,P<0.05).The CRTD of TC ranged from 0.26% to 0.53% and showed a downward trend (χ_trend²=13.26,P<0.05).The CDR varied from 0.26/100 000 to 0.82/100 000 for male residents and from 0.69/100 000 to 1.44/100 000 for female residents;the AAM for male residents varied from 0.15/100 000 to 0.44/100 000,with a downward trend(χ_trend²=25.93,P<0.05),and that for female residents varied from 0.30/100 000 to 0.77/100 000,respectively.The CDR of TC increased with the increment of age (χ_trend²=76.61,P<0.001);no TC mortality was registered among the residents under the age of 30 years and substantially more TC deaths were reported among the residents aged 80 years and above.Conclusion The mortality rate of thyroid cancer was relatively low and showed no obvious yearly variation,but an increasing trend with the increment of age,among the residents in Dalian city from 2005 to 2014.