Gavin O'Donovan was six years old when he accidentally bit into a spoon while eating a bowl of cereal, and the resulting cracked tooth saved his life.
His mother brought him straight to the dentist, but the young boy was so scared that he refused to sit in the dentist's chair and so was taken to hospital.
During a routine examination at the Bon Secours in Cork, it was discovered that Gavin had stage-four cancer. If his condition hadn't been detected then, he may not have lived to celebrate his seventh birthday.
Now fully recovered, Gavin is involved with this year's Daffodil Day, the annual fundraising campaign of the Irish Cancer Society (ICS), which is in its 27th year.
"When I was brought to the hospital, doctors discovered my blood pressure was sky high," he says. "After investigating further, they found a lump in my stomach that was possibly cancerous. So when the tooth was removed, I was referred to Crumlin Hospital where it was confirmed that I had a tumour in my kidney.
'I don't remember much about how my parents reacted, but can only assume they were extremely shocked and upset as I literally had no symptoms whatsoever – apart from night sweats. So to be told I had a very advanced tumour must have been horrendous.
"As soon as I started my first nine-week session of chemotherapy, I was so sick and threw up constantly. I lost my hair, which didn't bother me at all. But I was really upset about my lack of energy as I had always been tearing around the place. Then suddenly I wasn't able to do anything except lie down or read books – I hated it."
After the first round of chemo, Gavin (now 22) had his left kidney removed, then followed a full year of chemotherapy, during which he developed appendicitis.
"I felt dreadful most of the time and don't think I would have coped if it wasn't for my friends who visited me when I couldn't go to school and looked after me when I was there. And of course my family and medical team were fantastic.
"I now volunteer with the ICS because I want to reassure kids in a similar situation that there is light at the end of the tunnel.
'I was one of five children admitted to St John's oncology ward in Crumlin on the same day – three of whom didn't survive. I was so lucky because not only did I get through, I got stronger and fitter.
"A few years ago, I took up running and, with regular training, went from being exhausted after a few miles to taking on ultra marathons. I did my first one in September 2012 – it's a really intense experience involving daily training leading up to the race itself which is usually about 50 miles long.
"The fact that I can complete and enjoy them is brilliant as it wouldn't have seemed possible at one time. So if I can get better, others can too."