An Epidemiological Study On Leukemia For The Period Of 1992 To 2001 In Guoyang County, Anhui Province

Objectives To investigate the epidemiological features of leukemia among natural population in Guoyang and to analyze the influential factors for childhood leukemia. Methods Firstly, an epidemiological retrospective study was conducted with a natural population of 12.363 million during 1992-2001 in Guoyang, all death cases were collected by village doctors , we selected all leukemia cases and acquired information from hospitals around Guoyang in order to check if there were some lost cases, meanwhile we also collected the baseline information form village doctors in order to comfirm our conclusion. Secondly,a frequency matched case-control study was carried out among 106 childhood leukemia cases under 26 and 424 controls rated by age.case and control questionnaire(completed by parent) were used to rate influential factors and explore unknown influential factors among them.Results Totally,533 new cases of leukemia were found with the annual incidence of 4.32/100 000, 95% confidence internal of 2.92-4.53/100 000 and standardized rate of 3.48/100 000(4.53/100 000, standardized rate 3.96/100 000 for male and 4.05/100 000, standardized rate 3.25/100 000 for female), That is higher than the incidence rate of average lever of the whole country(U=5.94, P<0. 05). In the age group 60-70 years, we saw a climax of incidence, the incidence rate of male were higher than that of female (U=l. 30, P> 0. 05 ) ,A significantly statistical increase was found in incidence of leukemia, 4.64% annually, in which male was 8.49% annually,while female showed a slightly decreased trend , 0.27% annually. The incidence of childhood leukemia increased the fastest, 9.54% annually.the phenomenon of time-space clustering of ALL were found in some place ,most cases were congregated along the Guoyang river.when taking season distributions into consideration, summer ranked first,others in order,were spring,autumn,and winter.Univariate analysis revealed that multi-child family ,family history of auto-immune disease, smoking father, high birth order, abortion frequently before index pregnancy, overage parturien ,maternal severe anemia during pregnancy, the history of Psoriasis, the history of X-ray exposure , the history of blood transfusion, raticide use frequently in home , were positively associated with childhood leukemia; while high lever of family income, high lever of father's education,possess telephone in family, possess television in family, watch TV frequently, possess vehicle in family, possess electric iron in home were negatively associated with childhood leukemia. The result by multivariate unconditional logistic regression analysis indicated that family history of auto-immune disease, smoking father, high birth order, abortion frequently before index pregnancy, the history of Psoriasis , raticide use frequently in home ,the history of blood transfusion were the possible risk factors of childhood leukemia, and possess vehicle in family, possess television in family were the possible preventive factors for childhood leukemia. Conclusions The incidence of leukemia in Guoyang presented an upward trend during 1992 ~ 2001,it is essential to take comprehensive measures to pretect people ,espefially children ,from leukemia. Children with history of auto-immune disease, smoking father, high birth order, frequently aborted mather before index pregnancy, the history of Psoriasis, the history of blood transfusion, raticide use frequently in home represented a significant risk group for childhood leukemia. When planning intervention strategies on childhood leukemia, these factors shoud be emphasized to ensure optimal effectiveness of intervention.