Gabriel and his family were devastated but because he loves school he was determined to attend as much as possible.
"I [had] tubes in with antibiotics in them and just walked around at school. I just carried on as much as I could. The antibiotics fed straight into my heart and they were connected to baby bottles in my pocket. I went to the Tauhara College ball like that and people thought I was hiding alcohol. It was funny."
His friends were also a huge help. When Gabriel's hair started falling out, they all shaved their heads to match.
They would also would drag him out of the house and on outings, which helped keep his spirits up.
"They were the best thing ever. They make you feel normal. They never see me and be like 'oh you've got cancer, you should perhaps stay home', they're like 'you're coming to town'.
"When I started losing my hair, the boys all came around to my place and there was about 20 of them and we all just sat around with the razor."
The cancer affected Gabriel's sciatic nerve (a nerve which runs down the leg) and for four months he went to school in a wheelchair. But it wasn't all bad. His mates would vie to push him around and the school even gave him his own key to the lift in the technology block.
Gabriel's chemotherapy varies with each cycle but many sessions involved five days as an inpatient at Waikato Hospital, followed by a day in Rotorua Hospital two weeks later. All there was to do was to lie in bed attached to a drip, watching TV. For an active young man, it was hard to bear. Gabriel says some days were so bad he hardly cared whether he lived through it or not.
"Some days it sucked. Some days I literally felt like I was dying and that scared me, when you feel that you're not scared any more. Chemotherapy is like prison, but you're sick, and the hospital food is the worst thing."
The chemotherapy also messed with his brain.
"Chemo kills you, it stops you from doing everything. I couldn't think straight. I was trying to change the [TV] channel and my mind went blank. Some days I just didn't have any energy to do anything."
Gabriel is still having chemotherapy and then will have a course of radiotherapy to finish. Gabriel focuses on the good things coming up rather than the journey still ahead. He looks forward to things at school and the days he goes home from hospital. His goal for this year is to finish off his level 3 NCEA studies and, once treatment ends, to rebuild his fitness.
When the doctor announced Gabriel's cancer was gone, he "freaked out". His parents cried.
"It was the best Christmas present ever."
Once he's finished school, Gabriel's unsure what to do next. An overseas trip sounds appealing and then "I'll just do whatever".
"I'm not 100 per cent sure what I want to do, but it's going to be better than last year."