Matthew looks healthy but today the 18-year-old Perth student will have his stomach removed and become another grim statistic in a family struck down with a rare and devastating genetic condition.
He faces painstaking surgery to remove his stomach as well as part of his oesophagus and some lymph nodes, followed by reconstruction to join his oesophagus to the small intestine and create a small pouch that will act as a stomach for the rest of his life.
The Murdoch University health and physical education student and keen cricketer will spend up to two days in intensive care, two weeks in hospital and many more months learning to adapt to a new diet.
But it could save his life.
An endoscopy a few weeks ago revealed the lining of his stomach had hundreds of tiny polyps - not harmless ones, but genetically coded growths with the potential to turn into the lethal cancer that has claimed the lives of several young women in his extended family. It is a time bomb he will not risk.
"If I don't do this, I could die," Matthew told _The Weekend West _ only hours before he left for hospital.
"I'd rather do something now than wait until I have full-blown cancer."
Matthew has familial gastric polyposis, or GAPPS, an inherited condition that affects only one bloodline in Australia, all descendants of Matthias and Emma Powell, who arrived in Fremantle from England in the early 1900s.
They had nine children, four of them known to have had the genetic disorder. Since then, it has spread over five generations, putting more than 250 people across Australia at risk of developing deadly polyps or being carriers.
There is no genetic test, so doctors cannot predict who will get stomach cancer but dozens of family members have had endoscopies to see if their stomachs are smooth as they should be or bubbled with polyps.
Some decided to have their stomachs removed as a preventive measure and Matthew is the youngest so far.
His two younger siblings will soon be screened for polyps at Princess Margaret Hospital and two half-aunts aged in their 20s will have their stomachs removed in the next few weeks.
Gail, 60, a distant relative, knows what Matthew faces.
She had her stomach removed a year ago after polyps were found within a few months of her two daughters having their stomachs taken out. Her 29-year-old son has polyps, too, and will have surgery next month.
Genetic services can help only people who come forward for information, so Gail has found herself the unofficial family historian, trying to get word out to anyone related to Matthias and Emma Powell to be checked.
"I would hate for someone to die from this because they did not know they were at risk," Gail said. "I also want the medical profession to be more aware, too, because many don't seem to even know about this condition."
Professor Graeme Suthers from South Australian Clinical Genetics Services has been studying GAPPS with Genetic Services of WA to help advise Gail and her relatives.
"This is a huge family, now across three States in Australia, and each child of an affected parent has a 50-50 chance of inheriting this condition," he said.
"The dilemma is that the majority of these people with polyps won't get cancer from it, but we don't have a tool to separate those who should have a gastrectomy and those who should not.
"Ultimately, it comes down to an almost impossible dilemma for the family members."