Pregnancy outcomes after abdominal irradiation that included or excluded the pelvis in childhood Wilms tumor survivors: a report from the National Wilms Tumor Study

Abstract

Purpose: This report describes the pregnancy outcomes among 7 survivors of childhood Wilms tumor, who were treated on one of the National Wilms Tumor Studies (NWTS) with radiation therapy (RT) portals that extended beyond the flank.

Methods and materials: Pregnancy outcomes among female survivors of childhood Wilms tumor treated with abdominal irradiation in NWTS 1-4 were analyzed as part of the long-term follow-up study. Medical records and maternal questionnaires were used to gather information on pregnancy outcomes.

Results: A total of 130 patients received abdominal RT and survived to at least 15 years of age. Seven patients (5.4%) had at least 1 recorded pregnancy. The extent of RT fields was ascertained in 126 patients. For 4 patients, the extent of RT fields could not be determined. Twelve girls received RT using portals that included the upper abdomen but not the entire pelvis. Ten pregnancies were recorded in 5 of these patients; 9 resulted in live births, and 1 resulted in a miscarriage. One hundred fourteen girls received RT using portals that included the entire abdomen and pelvis. The abdominal RT dose distribution among these 114 patients was as follows: 9 received 0-10.49 Gy, 22 patients received 10.5-14.99 Gy, and 83 patients received 15+ Gy. Four pregnancies were recorded in 2 of these patients. After 21 Gy to the abdomen and pelvis in 1 patient, all 3 pregnancies resulted in miscarriages and fetal deaths. However, after 10.5 Gy, a normal live birth was reported in the other patient. Pregnancy-related complications were also more common if the RT portals included the pelvis.

Conclusions: Fertility can be preserved in children with Wilms tumor after upper abdominal RT (10-20 Gy) that does not include the entire pelvis. In rare instances, fertility can be preserved after low-dose whole-abdominal RT (10.5 Gy). The indications and dosages for RT currently used have been greatly refined compared to NWTS-1 and NWTS-2. Childhood Wilms tumor survivors should be considered to be at a high risk for infertility and pregnancy-related complications during their reproductive years. Prompt obstetric evaluation is indicated for optimal prenatal, antenatal, and postnatal care.