Some long-term survivors of childhood cancer are not getting the right care, says a survey.
More children than ever survive cancer
Cancer Research UK is calling for national guidelines to be implemented more effectively.
Many patients, even decades later, suffer health problems relating to either their original cancer, or caused by the powerful treatment given for it.
Only half of the doctors surveyed said they followed up all their patients for their entire lifetime.
The study, published in the journal Paediatric Blood and Cancer, surveyed 71 doctors responsible for long-term care of children.
The vast majority kept tabs on their patients for the standard five years after their "all-clear", but at that point, regular check-ups ceased for almost half.
While most of these involved either benign or low-grade cancers, 7% of the doctors said they discharged all or most of their patients, regardless of the nature of their cancer.
The researchers also asked 11,000 GPs of adult survivors of childhood cancers, and asked whether they were being regularly followed up at hospital clinics.
They found three in five GPs reported that this was not the case.
Patients who receive certain treatments for childhood cancer are at increased risk for other types of cancer later in life - and may also be more prone to heart problems.
Dr Mike Hawkins, Director of the CRUK Centre for Childhood Cancer, said: "The study found important variations between clinicians in decisions on who should be discharged and when.
"It's clear we need a system to improve the implementation of national guidelines, to ensure that survivors don't miss out on long-term surveillance should there be evidence they require it."
Professor Andy Pearson, Chairman of the UK Children's Cancer Study Group, said: "Among current major objectives of our group is the standardisation of clinical follow-up of survivors of childhood cancer and the continuing development of the most appropriate methods of follow-up."