The Trend And Age-Period-Cohort Study Of Colorectal Cancer Mortality Attributable To A Diet Low In Milk From 1990 To 2017 In China

Objective: A report in 2015 from the National Cancer Center has showed that colorectal cancer(CRC)ranks as the third most commonly diagnosed malignant neoplasm in China,and its incidence and mortality are increasing.In 2017,CRC burden attributable to a diet low in milk accounted for 17.1% of the total CRC burden in China.The aim of this study was to analyze the trends of CRC mortality due to a diet low in milk from 1990 to 2017 in China,and to estimate the effects of age,time period and birth cohort,so as to provide a reference for the prevention and control of CRC.Methods: In this study,mortality data of CRC attributable to a diet low in milk among people aged 25-79 years in China originated from the Global Burden of Diseases,Injuries,and Risk Factors Study 2017.Age-specific and age-standardized mortality trends of the risk-attributable CRC in China were analyzed by Joinpoint regression.The age-period-cohort model combined with intrinsic estimator algorithm was used to estimate the impact of age,time period and birth cohort on attributable CRC mortality.Results:1.From 1990 to 2017,the age-standardized mortality per 100,000 of CRC attributable to a diet low in milk among total population in China increased from 1.65 to 1.73,and from 1.83 to 2.13 among males.Whereas the rate decreased from 1.50 to 1.37 among females.The age-standardized mortality rates were higher among males than that among females.2.The average annual percent change(AAPC)of the age-standardized,risk-attributable CRC mortality for total population between 1990 and 2017 was 0.2%(95%CI:-0.1% — 0.5%).The age-standardized mortality rate for males showed an upward trend(AAPC=0.6%,95%CI: 0.1% — 1.0%),whereas the rate for females showed a downward trend(AAPC=-0.3%,95%CI:-0.4% —-0.2%).3.Age-specific mortality in total population: the mortality rates of CRC in total population aged 25-49(25-29,30-34,35-39,40-44,45-49)and 55-59 years decreased from 1990 to 2017 at an AAPC of 2.5%,2.8%,2.5%,2.2%,1.0%,and 0.7%,respectively(P < 0.05).In addition,the mortality rates of CRC in people aged 60-64,65-69,and 75-79 years increased at an AAPC of0.2%,0.8%,and 0.6%,respectively(P < 0.05).Age-specific mortality in males: the mortality rates of CRC in males aged25-44 years(25-29,30-34,35-39,40-44)decreased at an AAPC of 2.0%,2.5%,2.1%,and 1.9%,respectively(P < 0.05).The mortality rates of CRC in males aged 60-79 years(60-64,65-69,70-74,75-79)increased at an AAPC of0.8%,1.3%,0.6%,and 0.8%,respectively(P < 0.05).Age-specific mortality in females: the mortality rates of CRC in females aged 25-64 years(25-29,30-34,35-39,40-44,45-49,50-54,55-59,60-64)decreased at an AAPC of 3.0%,3.2%,2.9%,2.8%,1.5%,1.2%,1.6%,and0.6%,respectively(P < 0.05).The mortality rates of CRC in females aged75-79 years increased at an AAPC of 0.2%(P < 0.05).4.Age and birth cohort were influencing factors for CRC mortality due to a diet low in milk.The age effect increased with age in all age groups from 25 to 79 years(total population:-1.67 to 1.80,males:-1.68 to 1.85,females:-1.66 to 1.76).The cohort effect decreased with birth cohort from 1911-1915 to 1986-1990(total population: 0.44 to-1.07,males: 0.47 to-1.09,females:0.41 to-1.03).The total population and males born between 1926-1930 and1931-1935 had higher risk of CRC death than other birth cohorts.The period effect was not found in this study.Among all sub-models of age-period-cohort model,the whole model had the best fitting effect.Conclusions:1.According to the results of Joinpoint regression analysis,from 1990 to2017,no significant change was observed in the age-standardized mortality of CRC due to a diet low in milk among total population.However,the age-standardized mortality rate of attributable CRC increased at an AAPC of0.6% among males and decreased at an AAPC of 0.3% among females.2.The mortality rates of risk-attributable CRC in China increased with age and decreased with birth cohort.The period effect was not found in this study.3.Males and people over 60 years had higher mortality rates of CRC due to a diet low in milk.Therefore,it is very important for the high-risk groups to improve the health education,early screening and treatment.4.The age-period-cohort model combined with intrinsic estimator algorithm was used to fit the mortality rates of risk-attributable CRC in total population,males,and females;and the whole model had the best fitting effect.