Format

Send to

Choose Destination
Cancer Causes Control. 2015 Nov;26(11):1575-82. doi: 10.1007/s10552-015-0651-z. Epub 2015 Aug 11.

Birth order and risk of childhood cancer in the Danish birth cohort of 1973-2010.

Author information

1
Section of Environment and Radiation, International Agency for Research on Cancer (IARC), 150 Cours Albert Thomas, 69372, Lyon, France. schuzj@iarc.fr.
2
Department of Biostatistics, Bioinformatics and Biomathematics, Georgetown University, Washington, DC, USA.
3
Section of Environment and Radiation, International Agency for Research on Cancer (IARC), 150 Cours Albert Thomas, 69372, Lyon, France.
4
Survivorship Unit, Childhood Cancer Survivorship Research Group, Danish Cancer Society Research Center, Copenhagen, Denmark.
5
Survivorship Unit, Social Inequality in Survivorship Group, Danish Cancer Society Research Center, Copenhagen, Denmark.
6
Epidemiology and Cancer Statistics Group, Department of Health Sciences, University of York, York, UK.

Abstract

PURPOSE:

Many studies have investigated the possible association between birth order and risk of childhood cancer, although the evidence to date has been inconsistent. Birth order has been used as a marker for various in utero or childhood exposures and is relatively straightforward to assess.

METHODS:

Data were obtained on all children born in Denmark between 1973 and 2010, involving almost 2.5 million births and about 5,700 newly diagnosed childhood cancers before the age of 20 years. Data were analyzed using Poisson regression models.

RESULTS:

We failed to observe associations between birth order and risk of any childhood cancer subtype, including acute lymphoblastic leukemia; all rate ratios were close to one. Further analyses stratified by birth cohort (those born between 1973 and 1990, and those born between 1991 and 2010) also failed to show any associations. Considering stillbirths and/or controlling for birth weight and parental age in the analyses had no effect on the results. Analyses by years of birth (those born between 1973 and 1990, and those born between 1991 and 2010) did not show any changes in the overall pattern of no association.

CONCLUSIONS:

In this large cohort of all children born in Denmark over an almost 40-year period, we did not observe an association between birth order and the risk of childhood cancer.

KEYWORDS:

Birth order; Childhood cancer; Denmark; Leukemia; Risk factors

PMID:
26259524
DOI:
10.1007/s10552-015-0651-z
[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Springer
Loading ...
Support Center