Women who had radiation treatment on reproductive areas for cancer as children are more likely to experience a stillbirth or have a baby die in the first four weeks of life, a new report says.
The results are in a study published online Thursday by The Lancet, and add to growing evidence that children who survive cancer are at risk for a host of health and developmental problems later on, including recurrent cancer.
It's a paradoxical problem created by the happy success story of the fight against childhood cancer. More children are surviving bouts with the diseaseand are growing into adults who face health problems brought on by the damage radiation caused to their developing bodies.
Studies have shown that childhood cancer survivors face an increased risk of premature death from a host of chronic health problems. A study published in the Journal of the American Medical Association earlier this month found children who beat cancer are much more likely than others to die from a heart attack, stroke or another cancer 25 years or more after their diagnosis and treatment.
"I think we all think it seems incredibly unfair that these young cancer patients … now end up with these sometimes devastating side effects later in life," said Christine Williams, director of research at the Canadian Cancer Society Research Institute.
While it's not a new concept, a growing amount of research is being dedicated to uncovering the risks of radiation therapy on young bodies in which brains, organs, bones and tissues are not fully mature.
The data used in the new cohort analysis study came from the Childhood Cancer Survivor Study, which looked at more than 20,000 kids who were diagnosed between 1970 and 1986 and lived at least five years after diagnosis.
Researchers involved in the new study wanted to determine whether children who had radiation therapy would experience genetic mutations that could be transferred to their offspring and contribute to the risk of stillbirth or neonatal death.
Among the 1,148 men and 1,657 women in the new study, there were 4,946 pregnancies.
There was no link between testicular radiation in males and subsequent risk of stillbirth or neonatal death when trying to have children, according to the study.
But researchers found that girls who'd been treated with high doses of radiation to the uterus or ovaries before puberty faced a significant risk of stillbirth or neonatal death later on - 11 out of 82 pregnancies, or about 13 per cent.
John Boice, scientific director of the International Epidemiology Institute in Maryland and lead author of the study, said radiation can cause damage to the uterus or restrict blood flow, impeding growth of a fetus. Women in this category need to take special precautions if they decide to have children, he said.
"If you were a young girl treated with radiotherapy into your pelvis and you want to become pregnant, you can, but make sure to tell your doctor and be aware it might be a difficult pregnancy," Dr. Boice said.
Cancer therapy has evolved significantly since the individuals in this study were treated. For instance, treatments are targeted to specific areas to reduce potential damage elsewhere in the body.
Yet there is much that remains unknown about the role radiation therapy can play later in a cancer survivor's life, Dr. Williams said.
The Canadian Cancer Society is funding research looking at the long-term effects of cancer therapy on children.
The next step involves getting a better understanding of the risks and how targeted therapies can reduce them, Dr. Williams said.
Carly Weeks