Fertility studies in female childhood cancer survivors: selecting appropriate comparison groups

Mh van den Berg; E van Dulmen-den Broeder; A Overbeek; Cm Ronckers; W van Dorp; Lc Kremer; Mm van den Heuvel-Eibrink; Ga Huizinga; Jj Loonen; Ab Versluys; D Bresters; Cb Lambalk; Gjl Kaspers; Fe van Leeuwen

doi:10.1016/j.rbmo.2014.06.002

Fertility studies in female childhood cancer survivors: selecting appropriate comparison groups

Reprod Biomed Online. 2014 Sep;29(3):352-61. doi: 10.1016/j.rbmo.2014.06.002. Epub 2014 Jun 12.

Authors

Mh van den Berg¹, E van Dulmen-den Broeder², A Overbeek³, Cm Ronckers⁴, W van Dorp⁵, Lc Kremer⁴, Mm van den Heuvel-Eibrink⁶, Ga Huizinga⁷, Jj Loonen⁸, Ab Versluys⁹, D Bresters¹⁰, Cb Lambalk¹¹, Gjl Kaspers², Fe van Leeuwen¹²

Affiliations

¹ Department of Paediatrics, Division of Paediatric Oncology/Haematology, VU University Medical Center, PO Box 7057, 1007 MB, Amsterdam, The Netherlands. Electronic address: [email protected].
² Department of Paediatrics, Division of Paediatric Oncology/Haematology, VU University Medical Center, PO Box 7057, 1007 MB, Amsterdam, The Netherlands.
³ Department of Paediatrics, Division of Paediatric Oncology/Haematology, VU University Medical Center, PO Box 7057, 1007 MB, Amsterdam, The Netherlands; Department of Obstetrics and Gynaecology, VU University Medical Center, PO Box 7057, 1007 MB, Amsterdam, The Netherlands.
⁴ Department of Paediatric Oncology, Emma Children's Hospital, Academic Medical Center, PO Box 22660, 1100 DD, Amsterdam, The Netherlands.
⁵ Department of Paediatrics, Division of Paediatric Oncology/Haematology, ErasmusMC University Medical Center, PO Box 2060, 3000 CB, Rotterdam, The Netherlands; Department of Obstetrics and Gynaecology, Division Reproductive Medicine, ErasmusMC University Medical Center, Rotterdam, The Netherlands.
⁶ Department of Paediatrics, Division of Paediatric Oncology/Haematology, ErasmusMC University Medical Center, PO Box 2060, 3000 CB, Rotterdam, The Netherlands.
⁷ Department of Paediatric Oncology, Beatrix Children's Hospital, University of Groningen, University Medical Center Groningen, PO Box 30.001, 9700 RB, Groningen, The Netherlands.
⁸ Department of Paediatric Oncology, Radboud University Nijmegen Medical Center, PO Box 9101, 6500 HB, Nijmegen, The Netherlands.
⁹ Department of Paediatric Oncology, Wilhelmina's Children's Hospital, University Medical Center, PO Box 85500, 3508GA, Utrecht, The Netherlands.
¹⁰ Willem-Alexander Children's Hospital, Leiden University Medical Center, PO Box 9600, 2300 RC, Leiden, The Netherlands.
¹¹ Department of Obstetrics and Gynaecology, VU University Medical Center, PO Box 7057, 1007 MB, Amsterdam, The Netherlands.
¹² Department of Epidemiology, Netherlands Cancer Institute, PO Box 90203, 1006 BE, Amsterdam, The Netherlands.

PMID: 25047538
DOI: 10.1016/j.rbmo.2014.06.002

Abstract

Little information is available on the use of appropriate comparison groups for studies investigating late effects of childhood cancer. Two comparison groups in a nationwide study on reproductive function and ovarian reserve in female childhood cancer survivors were recruited (The Dutch Childhood Oncology Group Long-Term Effects After Childhood Cancer Cohort Study). Experiences of this process are reported. Two types of comparison groups were used: sisters of participating survivors and controls from the general population. A total of 352 out of 580 (61%) of the participating survivors who had a sister gave permission to invite them for the study. The participation rate of sisters was much higher than control participants from the general population (74% versus 21%, respectively), whereas considerably more effort was involved in recruiting controls from the general population. Participants in this group were significantly older and more highly educated than sister controls (P < 0.001 for both groups). No significant differences were observed between both types of comparison groups in several fertility-related characteristics, suggesting minimal bias owing to selective participation. Researchers setting up a study to investigate late effects among survivors of childhood cancer should carefully consider the advantages and disadvantages of using various types of comparison groups.

Keywords: childhood cancer survivors; comparison groups controls; female fertility; late effects.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adult
Cohort Studies
Female
Fertility / physiology*
Humans
Neoplasms / physiopathology*
Patient Selection*
Research Design*
Siblings*
Surveys and Questionnaires
Survivors*