Increasing numbers of children are being cured of their disease and surviving years after a single or tandem PBSCT. The intensity of the treatment prior to, during, and after transplant can cause major effects not apparent for months or years. This section describes a few of the common long-term side effects that sometimes develop after transplant.

Dental development

Certain chemotherapy drugs, administered in high doses prior to transplant, may result in improper tooth development and blunted or absent tooth roots in children who had a transplant when they were younger than 5 years of age. Your child should have a comprehensive dental examination prior to the transplant and a dental follow-up after recovery from the PBSCT.

Thyroid function

Children who receive only chemotherapy do not develop thyroid deficiency as a result of treatment. If, however, your child receives radiation therapy to the brain and spinal cord, either before or following recovery from a transplant, she should be monitored for thyroid deficiency. Tablets containing thyroid hormone are usually effective in treating the problem.

Puberty and fertility

If your child receives cranial radiation, either before or following recovery from a transplant, delays in puberty and sexual development can occur. In addition, some of the drugs given in high doses during conditioning (e.g., cyclophosphamide, thiotepa) can cause changes in future fertility (the ability to become a biological parent). For this reason, boys who have gone through puberty should bank sperm before treatment begins. You may also be told about any experimental protocols that are attempting to preserve fertility in girls.

Any child or teen who had a transplant should be followed closely by a pediatric endocrinologist, who can prescribe hormones (testosterone for boys, estrogen and progesterone for girls) to assist in normal pubertal development and can assess fertility in older survivors.

Second cancers

Children who receive a PBSCT have a small risk of developing a second cancer. The risk depends on the chemotherapy drugs given during conditioning. Use of etopoide and cyclophosphamide increases the risk of second cancers.

Because transplants are relatively new treatments for children and teens with brain and spinal cord tumors, the overall impact and long-term effects are not yet clear. Your child’s doctor can explain known risks given your child’s disease and treatment.