Children of Childhood Cancer Survivors Do Not have Increased Risk of Down Syndrome

November 12, 2012

Children of Childhood Cancer Survivors Do Not have Increased Risk of Down Syndrome

If you are concerned about offspring you want to have after being a survivor of cancer as a child, you need to put your mind to rest. Recent studies indicate that children who survived chemotherapy or radiation treatments do not have an greater increase for birth defects as compared to children of cancer survivors who did not go through these types of cancer treatments. The current study reported that 2.7% of survivor’s children had at least 1 birth defect such as Down syndrome, achondroplasia (short stature) or cleft lip. Based on the sample size, 3% of children with mothers exposed to chemotherapy with alkylating agents had genetic birth defects. Compare that to 3.5 percent of children of cancer survivors who had no exposure.

This is good news for cancer survivors who have had radiation/chemotherapy who want to start a family and are looking for guidance. The main author Lisa Signorello, Sc.D, from Vanderbilt University Medical Center hopes this will provide information to childhood survivors and helping them with family planning. Clearly, children who are cancer survivors are concerned about many unknowns of their therapies and how that effects their ability to bring about normal children into their lives. The information coming from these studies indicate that they have no greater risk for genetic complications such as Down syndrome, achondroplasia or cleft lip, in producing offspring and this should put their minds to ease in starting a family.

Although, young females receive drastic radiation and chemotherapy to the pelvic region and receive damaging effects to their uterus, in the past this has been associated with an increased risk to miscarriage, premature births, and possible infertility. It is now known that this is not the case. Earlier studies conducted were not complete and involved small sample size, however even those studies didn’t report an increase in birth defects. Nevertheless, it was assumed by the medical community that an increase in birth defects would be present because DNA damage was inevitable.

Dr. Signorello and her colleagues examined data (meta-analysis) from past childhood cancer survival studies (a large study of treatments and outcomes) from 1970 to 1986 from 4,699 children who where from cancer survivors who had radiation/chemotherapy. The parent survivors were given questionnaires about their children’s health and the parent’s medical records were examined focusing on their history of radiation therapies to testes and ovaries and chemotherapy with alkylating agents.

Of the survivors studied 63% had received radiation for cancer and 37% had received chemotherapy with alkylating agents. Overall 2.7 percent of survivor’s children had at least 1 birth defect such as Down syndrome, achondroplasia or cleft lip. So 3% of children with mothers exposed to chemotherapy with alkylating agents had genetic birth defects compared to 3.5 percent of children of cancer survivors who had no exposure.

Only 1.9% of children of male cancer survivors who received DNA damaging treatments were reported with such birth defects, compared to 1.7% of children of male survivors who did not have chemotherapy or radiation of this type. Researchers concluded that children of cancer survivors were not at a higher risk of birth defects due to their treatments and the percentages for Down syndrome, achondroplasia and cleft lip were not significantly different from cancer survivors who did not have radiation/chemotherapies.

The up shot is that the prevalence of birth defects among cancer survivor children in terms of Down syndrome, achondroplasia or cleft lip was similar to what has been reported with individuals who had cancer who did not receive radiation or chemotherapy. Further information is available in the Journal of Clinical Oncology and the American Society of Clinical Oncology.

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