Effects of Maternal Age and Cohort of Birth on Incidence Time Trends of Childhood Acute Lymphoblastic Leukemia

• Published in: Cancer epidemiology, biomarkers & prevention Vol. 16; no. 2; pp. 347 - 351
• Main Authors: MAULE, Milena M, MERLETTI, Franco, PASTORE, Guido, MAGNANI, Corrado, RICHIARDI, Lorenzo
• Format: Journal Article
• Language: English
• Published: Philadelphia, PA American Association for Cancer Research 01.02.2007
• Subjects: acute lymphoblastic leukemia; age-period-cohort; Biological and medical sciences; Birth Intervals; Birth Order; Child, Preschool; childhood cancer; Female; Hematologic and hematopoietic diseases; Humans; Incidence; Infant; Italy - epidemiology; Leukemias. Malignant lymphomas. Malignant reticulosis. Myelofibrosis; Linear Models; Maternal Age; Medical sciences; Poisson Distribution; Precursor Cell Lymphoblastic Leukemia-Lymphoma - epidemiology; Registries; Risk Factors; temporal trends; Tumors; Italy; Europe; Human; Acute leukemia; Malignant hemopathy; Lymphoid neoplasm; Epidemiology; Time variation; Incidence; Maternal age; Cancerology; Lymphoproliferative syndrome; Cohort study; Birth cohort; Acute lymphocytic leukemia; Child; Public health
• ISSN: 1055-9965; 1538-7755
• DOI: 10.1158/1055-9965.EPI-06-0425

Several studies report increasing trends in the incidence of childhood acute lymphoblastic leukemia (ALL). Because ALL may generate in utero , this study investigated if maternal age and birth cohort influence ALL temporal trends. Data on 252 ALL cases in children ages 1 to 5 years were extracted from the population-based Childhood Cancer Registry of Piedmont, Italy. Information on cases' maternal age and year of birth was obtained from the registry, whereas population data were obtained for children born in 1980 to 1997. Incidence rates were analyzed using an age-period-cohort approach, in which the period effect was represented by the child year of birth, the age effect by the maternal age at the time of delivery, and the cohort effect by the maternal birth cohort. ALL incidence increased over the study period [annual percentage change 2.49%; 95% confidence interval (95% CI), 0.09-4.93]. A linear effect of the maternal time variables ( P = 0.012) was found, which was equally described by maternal age (direct association) and maternal birth cohort (inverse association). The annual percentage change was 1.83% (95% CI, −0.59-4.31), when maternal age was included in the model, and 5.72% (95% CI, 2.29-9.27), when maternal year of birth was included. In conclusion, maternal characteristics substantially affect temporal trends in childhood ALL incidence. (Cancer Epidemiol Biomarkers Prev 2007;16(2):347–51)