Watch Cary Johnston's full report below
Interviewees: Joanna Warner, Mother & Stephen Richards CEO, Solving Kids' Cancer & Dr Juliet Gray, Associate Professor, Consultant Paediatric Oncology
Five-year-old Oliver Warner, from Bramley in Hampshire, is travelling abroad for a new experimental cancer treatment.
In 2016, Oliver was diagnosed with a rare childhood cancer called neuroblastoma, which affects the adrenal gland and nervous system.
It is most common in children under the age of 5.
Despite chemotherapy, Oliver recently suffered a relapse.
He is currently receiving treatment in Barcelona.
The new experimental antibody therapy, a form of immunotherapy, was developed in America and is now tested internationally, including in Spain.
However, the treatment comes at a private financial cost to families.
UK charity Solving Kids' Cancer is doing its bit to help administer any funds raised to help Oliver.
Immunotherapy is currently administered to children on the NHS, with results dependent on individual medical circumstances.
One such centre is at the University Hospital Southampton NHS Foundation Trust, where experts say the new American treatment may eventually be trialled in the UK.
In the meantime, campaigners are trying to raise awareness of the disease, in a bid to better understand how to combat it.