Parental Age As a Risk Factor of Childhood Leukemia and Brain Cancer in Offspring

TLDR

Accumulation of chromosomal aberrations and mutations during germ cell maturation is a likely mechanism for these findings. The study used the Swedish Family‑Cancer Database, covering over 6 million individuals born after 1940, to analyze time trends in childhood leukemia and brain cancer from 1960 to 1994 and the effect of parental age on about 1,500 cases of each cancer. Incidence of childhood leukemia and brain cancer rose from 1960 to 1994, driven mainly by low‑grade astrocytoma, while leukemia increased moderately until around 1980; parental age was linked to excess risk—offspring of mothers over 35 had about a 50 % higher leukemia risk and offspring of fathers over 35 had about a 25 % higher brain cancer risk—helping explain secular trends and excess risks in offspring of the well‑educated. Epidemiology 1999;10:271–275.

Abstract

We use here the Swedish Family-Cancer Database to analyze the time trends in childhood leukemia and brain cancer between 1960 and 1994 and the effect of parental age on childhood leukemia and brain cancer of some 1500 cases each. The database includes all persons born in Sweden after 1940 with their biological parents, over 6 million individuals, whose cancers were retrieved from the Swedish Cancer Registry from years 1958–1994. Incidence in cancer increased from 1960 to 1994; low grade astrocytoma accounted for most of the increase, whereas high grade astrocytoma has not increased in incidence. There has been a moderate increase in leukemia to about 1980. We found a parental age effect for both leukemia and brain cancer, with the former (of about 50% excess in those over 35 years) being mediated by maternal age and the latter (of about 25% excess) by paternal age. Accumulation of chromosomal aberrations and mutations during the maturation of germ cells is a likely mechanism for these findings. They can help to explain partially the secular trends of these malignancies and the excess risks in offspring of the well educated. (Epidemiology 1999;10:271–275)