Former Deputy Prime Minister Nick Clegg and his wife, Miriam Gonzalez Durantez, have spoken for the first time about their son's treatment for cancer.
Antonio, now 15, was diagnosed with Hodgkin lymphoma last September.
After treatment at University College Hospital in London, including chemotherapy, he is now in remission.
His parents told ITV's Lorraine programme how telling their eldest son he had blood cancer was one of the "toughest things" the family had faced.
"It is like a word bomb - certainly if you are not familiar with it, as we were not," said Mr Clegg.
"Your initial reaction, as we found, was like any mum or dad - it is irrational but you almost have this physical wish to take it off your kid and take it yourself."
Ms Gonzalez Durantez said Antonio had gone to his GP after finding a small lump on his neck, which had not been particularly painful.
"We were very lucky that he [the GP] spotted that it could be something more serious," she told host Lorraine Kelly.
"We dealt with it by carrying on and trying to keep things as close to the routine that we had beforehand and also being very open.
"The day that he was told, and I think that probably us telling him is one of the toughest things that we have ever done, the following day he went to school, he stood up and he told everybody, 'I have cancer.'
"That's the way he dealt with it, but other children and other families deal with it in a different way, you have to find your way."
Mr Clegg said: "His lymphoma was all over his chest and his neck and he gets tested every three months, I think for a couple of years, so there is always a slight spike of anxiety with us every three months, but basically he is on the road to recovery.
"Interestingly, the thing he was most concerned about was sort of falling behind his classmates. His anxiety was more about keeping up with his classmates, keeping up at school. So, it was very impressive actually."
He added the couple's other children, Alberto and Miguel, had taken the news well.
"Once they heard from us that he will be OK, again they are just so, so practical - just, 'OK then,'" he said.
Mr Clegg praised the way Antonio had handled the diagnosis and treatment, which resulted in severe side effects including hair loss, vomiting and fatigue.
What is Hodgkin lymphoma?
- Hodgkin lymphoma is a type of lymphoma, cancer of the lymph circulation system
- Symptoms can include enlarged lymph nodes in the neck, under the arm or in the groin
- It is the most common cancer among children and young people
- More than 1,100 people under the age of 24 are diagnosed in the UK every year
The Cleggs are trying to raise awareness of the charity Bloodwise, which launched a report on Wednesday urging more research into less toxic treatments for children with cancer.
Ms Gonzalez Durantez said: "[With] chemotherapy, they poison your body so that you can get cured and it's a shock to see it happen.
"We do realise how incredibly lucky we are both with the fact that the treatment has worked and how well he seems."
Dr Alasdair Rankin, Bloodwise's director of research, said: "The reality is that one in five children diagnosed with the most common type of leukaemia still do not survive, and that those who do often experience devastating side effects both during and after treatment.
"This is simply not good enough. We need to save every child's life, make the treatment process much kinder and give them the life they would have had without cancer."