ABSTRACT
<p><b>OBJECTIVE</b>Leukemia is a major cause of death of children in China, which accounts for 50 % of all cancers of children. Data from Tianjin Cancer Hospital was analyzed for mortality of leukemia in children under 20 years from 1981 to 2000 in the city of Tianjin.</p><p><b>METHODS</b>All physicians and medical staff of the hospitals and clinics in the registry area were responsible for filling out the report forms for every new case diagnosed as malignant tumors. Death certificates for malignant tumors have been registered at the local police station and the residential files were checked. All cancer cases with insufficient information were traced to his/her family and relevant persons worked in the clinic. Tianjin Cancer Registry Center periodically conducted an active re-checking program to review all patient records on cancers that was not registered in this period. Tumors diagnosed in this study were coded according to the International Classification of Diseases for Oncology (ICD-O). Mortality rates were calculated by age, sex and date of death.</p><p><b>RESULTS</b>The types of acute lymphoid leukemia, acute myeloid leukemia and chronic myeloid leukemia were the most common types of childhood leukemia in Tianjin, comprised 69.3%, 20.9 % and 8.0%, respectively. The mortality for childhood leukemia decreased slowly during the period of 1981 to 2000 in Tianjin. Mortality and morbidity ratios were 0.51.</p><p><b>CONCLUSION</b>Combined with characteristics of individual forms of childhood leukemia mortality, further epidemiological research is needed to prevent childhood leukemia.</p>