When Ian Terrey looks in a mirror, he says the face looking back at him is "not human" but he does not care because he has cheated death — at least twice.

* Warning: This story contains an image of a medical situation some may find distressing *

Twenty years ago, the Caloundra, Queensland, resident was diagnosed with a Stage 5 melanoma and given three months to live.

Since then, Mr Terrey has had major surgery which saw his jawbone removed and replaced with bone from his leg.

Tissue from his forehead was rotated south to create his new mouth, meaning that until baldness happened, he had hair growing there.

He said he received another "terminal diagnosis" in 2002 when a secondary cancer was picked up between his heart and lungs.

At the time, he was told he had a 40 per cent chance of "dying on the operating table".

And in 2015, he was diagnosed with high-grade prostate cancer but recently learnt his cancer marker blood test levels, called a PSA, were dropping.

Mr Terrey underwent a jaw reconstruction using a rotation flap from his forehead and a bone graft from his leg in 2000. ( Supplied: Ian Terrey )

Started with spot on the lip

Mr Terrey's son David said doctors were so perplexed by his father's recoveries they had suggested his body might have developed an immunity and was fighting off the cancer itself.

"My dad is 20 years past his use-by date," he said.

"He had a spot on his lip and had it checked out and it was a Level 5 melanoma and they gave him three months to live.

"He went and had three surgeries and after them, he had his jawbone removed.

"He has had every cancer under the sun now.

"Eventually the doctors have said his body has recognised a lot of the cancers as foreign agents and his immune system has kicked in and [he] is fighting it himself."

Mr Terrey says that after winning too many meat trays in raffles, he learned how to eat steak again. ( ABC Sunshine Coast: Megan Kinninment )

Immunotherapy 'the way forward' says surgeon

Harnessing the body's immune system to treat cancer is a new treatment breakthrough.

The 2018 Nobel Prize in medicine was awarded for research on cancer immunotherapy.

Melanoma facts Melanoma is the third most common cancer in Australian men and women

Melanoma is the third most common cancer in Australian men and women Australia and New Zealand have the highest rates of melanoma in the world

Australia and New Zealand have the highest rates of melanoma in the world The Queensland rate of melanoma vastly exceeds rates in any other jurisdiction, nationally or internationally

The Queensland rate of melanoma vastly exceeds rates in any other jurisdiction, nationally or internationally The melanoma rate doubled in the 20 years between 1986 and 2006 and is still on the rise

The melanoma rate doubled in the 20 years between 1986 and 2006 and is still on the rise In Australia, one in 14 men and one in 24 women will be diagnosed with melanoma at some point Source: Melanoma Institute of Australia

Sunshine Coast plastic and reconstruction surgeon Dr Amy O'Connor said immunotherapy was "the way forward" in cancer treatment.

However, she said cases of survival like Mr Terrey's were far too rare.

"It is spectacular he has done so well. He has been really lucky," Dr O'Connor said.

"So many people have a very different course."

Mr Terrey has no idea why he is still alive but is simply happy that he is.

He has never allowed cancer or his facial deformity to define him and has instead developed a cracking sense of humour about it.

Sense of humour in face of adversity

Few would describe having their jawbone removed and replaced with part of their fibula as something involving a "bicycle chain with WD40" as Mr Terrey refers to his surgery.

He also has no shame of describing the messy way he eats.

"I haven't got any feeling in my [new] jaw," he said.

"I actually use a mirror to eat as I've only got half a mouth opening and, with no feeling, I dribble a fair bit."

He said he decided to learn to eat steak after winning too many meat raffles.

"I was going around Australia and I kept winning these steaks and things so I decided to try one of them," he said.

"I've learned to chew steak on the leg bone that's there [in my mouth]. It's got bumps in it and has teeth above it."

He said doctors had told him they would transfer skin from his forehead to his lower face because of its texture.

"I wanted skin from my bum so I could say 'kiss me on my bum', but they said it sags and now that I've got older I can tell you it's true," he laughed.

Aiming for 2000 Olympics

At the time of his initial diagnosis, Mr Terrey was a teacher and actively involved in amateur theatre.

He still remembers the doctor's look as he was given the diagnosis.

"When your doctor's got tears in his eyes, [the chance of survival] isn't high," Mr Terrey recalled.

"I didn't think I'd see Christmas 1999, I don't think anyone else did either.

"I really didn't think I was going to live, but I wanted to see the 2000 Olympic Games in Sydney."

Ian Terrey (far right) in one of the Caloundra Chorale theatre productions ( Supplied: Caloundra Chorale and Theatre Company )

But he did not prepare for death.

"I don't think I was preparing for the end; you are concentrating on what you are doing to improve and get better," he said.

"It took me a while to get around it. I 'lost it' a few times — little things [would] happen and I would lose it for a week.

"It got better as time got on, but I couldn't put it aside as you look in the mirror every day."

Mr Terrey is candid about his reflection in the mirror.

"Well I'm not looking at a human being," he said.

"I look in the mirror and that's the face I've got now."

Mr Terrey accepts the changes he has experienced over the past two decades.

"You can't go through this and not change, but everything in life changes you," he said.

He remains active in amateur theatre and has taken part in many plays and is presently directing his own play, due to open in February.