Follow-up care after treatment for Wilms' tumor is important. Even when there are no longer any signs of cancer, the disease can return if undetected cancer cells remain somewhere in the body after Wilms' tumor treatment. During follow-up for Wilms' tumor treatment, doctors will monitor the child's recovery and check for recurrence of the cancer. Checkups help to ensure that any changes in the child's health are noted and treated if needed. Between scheduled visits, you should contact the doctor if your child has any health problems.