ESPE Yearbook of Paediatric Endocrinology

Adult Life After Childhood Cancer in Scandinavia Study Groupkenborg@cancer.dk Cancer 2021; 127: 3881-3892. PMID: 34297360.

Brief Summary: This register-based cohort study analysed the likelihood of live birth among female childhood cancer survivors (CCSs) diagnosed in between 1943 and 2006, in comparison with the general population. The prevalence of first live birth was lower in CCSs compared to matched controls (63% versus 80.9%).

Patients were identified using the unique population-based Nordic registries of Denmark, Finland, Iceland, Norway and Sweden, collecting data about 8,886 CCSs and 62,903 age- and country-matched controls, for a long follow-up. For every CCSs, data about radiotherapy (RT) were categorized according to target organ (uterus, ovaries or pituitary) and estimated radiation dose (low, low-medium, medium-high, high or unknown). Unfortunately, in this work data about chemotherapeutic regimen or hematopoietic stem cell transplantation were lacking, so the concomitant impact of these factors on fertility was not analysed.

First live birth from age 15 years or for 5 years after cancer diagnosis were analysed by cancer type, age at cancer diagnosis, radiation status and dose and treatment period. The results confirmed the reduction in first live birth in CCSs compared to matched controls (63% versus 80.9%); after adjustment for country and maternal birth year, CCSs had 21% lower probability of livebirth than the general population at every maternal age. Malignancies with more reduced probability of livebirth were germ cell, central nervous system and renal tumours, probably reflecting a more extensive RT use in these malignancies.

The relative probability of a first live birth in CCSs increased with time, and the same trend was seen in all maternal age groups. Among women whose cancer was diagnosed between 1954 and 1989, the probability of a live birth at age 30 years was 31% to 35% lower than in controls, whereas it was only 9% lower for CCSs diagnosed between 1990 and 1999 and 6% lower in survivors of cancers diagnosed between 2000 and 2006. On the contrary, cumulative incidence of a first live birth did not change in the general population during the decades, confirming that the main determinant of this improvement was not a variation of background rates, but a significant improvement of treatment protocols and attention on fertility issues, in particular for patients receiving RT.

These improving trends with time are reassuring and underline the importance of focusing the future research on specific fertility risk in relation to cancer type and treatment protocols. Female patients with childhood cancer should receive personalized counselling regarding their specific infertility risk and fertility preservation options, in order to make informed decisions about future family planning.