Monitoring Pregnancy Key After Wilms Treatment

Women who received radiation for a certain type of childhood cancer are at increased risk for complications during pregnancy, and therefore should be carefully assessed and closely monitored by their obstetricians. These conclusions were part of a National Wilms Tumor Study Group (NWTSG) report published in the May issue of the Journal of Clinical Oncology. Daniel M. Green, MD, Department of Pediatrics, Roswell Park Cancer Institute (RPCI), is the lead author.

"This is the first study to evaluate the risk of increased complications of pregnancy due to prior Wilms Tumor treatment," said Dr. Green. "We found that irradiated female survivors of Wilms Tumor are at increased risk for early or threatened labor and that their children are more likely to be premature and may have increased risk of certain congenital defects. These increased complications were not seen in the partners of male survivors who received the same treatment."

The study was limited to pregnancies of patients or partners of patients who received either no abdominal or only flank irradiation as part of their initial course of treatment. The NWTSG received reports regarding 427 pregnancies with duration of 20 weeks or more, including 409 liveborn singletons. The most common issues identified by the irradiated women included malposition of the fetus, and early or threatened labor. Offspring of the irradiated female patients were more likely to have low birthweight and to be premature (less than 36 weeks gestation). An increased percentage of the offspring had one or more congenital malformations such as cleft lip and palate, undescended testes, clubfoot etc.

"We found that the identified complications were more frequent among women who received a higher radiation therapy dose," continued Dr. Green. "Additional research is needed to validate these observations and determine if survivors who received lower flank radiation therapy are less likely to have these complications with a pregnancy. Survivors and their physicians must be aware of these issues when guiding a pregnancy to term."

Wilms' tumor is a cancer of the kidney most often seen in children under the age of seven. Approximately 400 new cases will be diagnosed this year and when diagnosed early, the five-year survival rates can reach 92 percent.

Roswell Park Cancer Institute, founded in 1898, is the nation's first cancer research, treatment and education center and is the only National Cancer Institute-designated comprehensive cancer center in Western New York.