This study is for patients with neuroblastoma, a type of cancer that usually affects children, who are in remission (no signs of cancer). It uses a drug called Difluoromethylornithine (DFMO), taken by mouth for two years. The study aims to see if DFMO can help stop the cancer from coming back.

To join, patients must have had a confirmed neuroblastoma diagnosis, be younger than 31, and have been high-risk when diagnosed. They must currently show no signs of cancer. The patients will be divided into different groups based on their treatment history and the stage of remission.

• Duration: The study lasts for 730 days (2 years).
• Eligibility: Must be in complete remission and under 31 years.
• Safety: Regular health checks are required to ensure patients' safety.

Participants must have a good health status and agree to regular check-ups. Women must test negative for pregnancy and use effective birth control. They cannot be on other experimental drugs or cancer treatments. This trial is conducted in multiple centers, meaning several hospitals or clinics are involved, and participants must give their consent to join, following FDA guidelines.