A summary of: Iyer, N.S., Trager, L., Gaughan, J., et al. Paediatric dental outcomes among children exposed to chemotherapy in utero. Int J Paediatr Dent. 32(1):116-122 (2021). doi: 10.1111/ipd.12801
Introduction:
Odontogenesis begins during foetal development (with primary teeth forming from 11-14 weeks), and while cancer in pregnancy may be rare, when cases as such appear, clinicians tend to avoid starting chemotherapy treatment out of concern of the potential harmful effects it may have on the growing foetus.
An association between chemotherapy and the development of dental abnormalities, such as enamel hypoplasia, in childhood cancer survivors has been shown; however, no previous studies have yet evaluated the effects of chemotherapy on dental development in utero.
Therefore the aim of this study was “to understand whether children exposed to chemotherapy in utero had an increased risk of dental abnormalities similar to cancer survivors exposed in early childhood.”
Materials and methods:
Individuals in the Cancer and Pregnancy Registry (originally established in 1996) who both did and didn’t undergo chemotherapy whilst pregnant were included in this study.
After the child exposed to chemotherapy in utero turned two years old, their mothers were contacted to ask for permission to be a part of the present study and share the following information: details about their exposed children and unexposed children’s dental practice. The children’s dentists were asked to fill out a questionnaire about their dental abnormalities (if they had any).
Results:
No statistical difference was found between exposed and unexposed children in the occurrence of dental abnormalities.
An association between cancer type, chemotherapy regimens and an increased risk of dental abnormalities was not found. Furthermore, exposure to chemotherapy at an earlier stage of foetal development or undergoing a higher number of chemotherapy cycles also did not show an increased risk/likelihood of dental abnormalities.
Table summarising dental outcomes comparison between exposed and unexposed children
Discussion and conclusion:
Although the results of the study suggest there is no increased risk of dental abnormalities with exposure to chemotherapy in utero (which is reassuring for patients), this may be because none of the participants underwent/received chemotherapy before 14 weeks (approximately when primary dentition begins to develop).
The results in the present study are different to those found in reports/articles that looked into childhood cancer survivors and the development of dental abnormalities. Previously, specific chemotherapy drugs have been associated with dental abnormalities, such as cyclophosphamide and vincristine. Additionally, due to their immuno-compromised state, they are more prone to developing dental infections. These stark differences in findings may be due to other variables, such as increased levels and/or duration of exposure to chemotherapy.
Going forward, further research is needed to ascertain this association.
Written by: Shivani Chohan, BDS Y3, University of Manchester