Chemo and radiation therapy 'do not cause birth defects'
A study in the US has found that having radiation treatment or chemotherapy for cancer as a child does not increase the risk of birth defects among those who have children later in life.
Scientists at Vanderbilt University in Tennessee and the International Epidemiology Institute in Maryland analysed the medical records of cancer survivor's children who had previously been given radiation or chemotherapy and compared them with equivalent stats about the children of cancer survivors who did not undergo such treatment.
The researchers, writing in the Journal of Clinical Oncology, found that children of cancer survivors were not at a higher risk for birth defects stemming from their parents' exposure to chemotherapy or radiation.
Lead author Dr Lisa Signorello said childhood cancer patients frequently receive intensive treatments, which can save their life but may affect their ability to have children in future.
Previous research has already suggested that DNA damage from a parent's treatment is not passed down to their offspring.
But the team said one of the strengths of their study was their comparison to the children of other cancer survivors, rather than the children of people randomly sampled from the general population.
Dr Signorello said individuals in the general population may not be as thorough in reporting their children's health problems as childhood cancer survivors.
Meanwhile, the children of cancer survivors may be under heightened clinical surveillance, which may lead to the impression that they have a higher rate of birth defects.
However, the researchers found that the overall prevalence of birth defects among the children of cancer survivors was very similar to that reported in the general population.
The team used information contained in the Childhood Cancer Survivor Study, which covers more than 20,000 childhood cancer survivors diagnosed between 1970 and 1986.
They looked at data from 4,699 children of 1,128 men and 1,627 women who were five-year childhood cancer survivors.
They found genetic birth defects in 3 per cent of children born to mothers who had been given radiation or treated with DNA-damaging chemotherapy.
This was compared with 3.5 per cent of children of mothers who were cancer survivors but did not have such exposures.
Meanwhile, just 1.9 per cent of children of male cancer survivors who received these DNA-damaging treatments had such birth defects, compared with 1.7 per cent of children of male survivors who did not have this type of treatment.
The findings may provide extra reassurance for cancer survivors who are worried about the potential effects of their treatment on their children.
Martin Ledwick, head information nurse at Cancer Research UK, said: "When they become parents or are thinking of becoming parents, survivors of childhood cancer are often concerned about the impact their previous treatment might have on their own children. This study adds to previous data that can reassure them that their treatment for cancer is unlikely to lead to birth defects in their own children."
Copyright Press Association 2011