Parental age and risk of childhood cancer: a pooled analysis.
BACKGROUND
Few risk factors for childhood cancer are well-established. We investigated whether advancing parental age increases childhood cancer risk.


METHODS
We assessed the relationship between parental age and childhood cancer in a case-control study using pooled population-based data. Our pooling was based on linked cancer and birth registry records from New York, Washington, Minnesota, Texas, and California. Subjects included 17,672 cancer cases diagnosed at ages 0-14 years during 1980-2004 and 57,966 controls born during 1970-2004. Individuals with Down syndrome were excluded. Odds ratios and 95% confidence intervals were calculated by logistic regression for the association between parental age and childhood cancer after adjustment for sex, birth weight, gestational age, birth order, plurality, maternal race, birth year, and state.


RESULTS
Positive linear trends per 5-year maternal age increase were observed for childhood cancers overall (odds ratio = 1.08 [95% confidence interval = 1.06-1.10]) and 7 of the 10 most frequent diagnostic groups: leukemia (1.08 [1.05-1.11]), lymphoma (1.06 [1.01-1.12]), central nervous system tumors (1.07 [1.03-1.10]), neuroblastoma (1.09 [1.04-1.15]), Wilms' tumor (1.16 [1.09-1.22]), bone tumors (1.10 [1.00-1.20]), and soft tissue sarcomas (1.10 [1.04-1.17]). No maternal age effect was noted for retinoblastoma, germ cell tumors, or hepatoblastoma. Paternal age was not independently associated with most childhood cancers after adjustment for maternal age.


CONCLUSIONS
Our results suggest that older maternal age increases risk for most common childhood cancers. Investigation into possible mechanisms for this association is warranted.
Johnson
Kimberly J
KJ
Division of Epidemiology/Clinical Research, Department of Pediatrics, University of Minnesota, Minneapolis, Minnesota, USA.
Carozza
Susan E
SE
Chow
Eric J
EJ
Fox
Erin E
EE
Horel
Scott
S
McLaughlin
Colleen C
CC
Mueller
Beth A
BA
Puumala
Susan E
SE
Reynolds
Peggy
P
Von Behren
Julie
J
Spector
Logan G
LG
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D009369:Neoplasms / Q000453:epidemiology*; D016017:Odds Ratio; D010290:Parents; D018570:Risk Assessment; D014481:United States / Q000453:epidemiology