But at the age of 64, when others are planning retirement, Dr Finlay has recently signed up to a further worldwide research programme which, he said, would "really move forward our research".

He explained: "Survival rates have improved dramatically over the last 20 years.

"But 30 per cent of children with malignant brain tumours are still dying. We are studying who they are and how we can pick them up earlier to modify their treatment so they can still come out cured."

Dr Finlay was inspired to dedicate his life to helping others both by what he learned, age 13, at Carmel College, as well as by his experience of life-threatening illness within his own family.

Dr Finlay was the only child of Grimsby-born Minnie, nee Sivner, and Polish-born Holocaust survivor Motel Finlay.

Minnie had previously been married to Mancunian Micky Young, who died in the early 1940s.

The Youngs had one daughter, Isolde, and fostered Margot Showman, nee Feigmann, who had arrived on the last Kindertransport and whose story was featured in the Jewish Telegraph earlier this year.

Serving in the Polish army, Motel Finlay was billeted with newly-widowed Minnie in Cheetham Hill.

"My father and another soldier were billeted with my mother for Rosh Hashana," Dr Finlay said.

"I don't know how they communicated. He couldn't speak English and my mother couldn't speak Yiddish, let alone Polish. He fell in love with her chicken soup."

Dr Finlay was therefore born with two elder sisters. Of Margot, who was the elder of the two and with whom he is still in regular contact, he says: "She was always an elder sister to me and still is. She looked after everybody, and still does".

Margot's nurturing qualities came to the fore when Isolde contracted systemic lupus erythematotus at the age of 20.

Dr Finlay - who had just been sent to Carmel College at the age of nine after attending Cassel Fox and Broughton Jewish Primary schools - recalled: "She was getting dressed for a wedding when she suddenly lost vision in her eye, went weak and feverish and was rushed to hospital.

"She had basically had a stroke, kidney failure and a multi-system disease."

She died at the age of 29.

Well aware of what was happening at home, Dr Finlay researched the then chronic auto-immune disease.

He said: "I was nine and had just moved to Carmel. I looked up things. I was keen to find out what was going on. It was certainly a significant factor why I went into medicine.

"I realised here was my relatively young sister affected with a disease. I felt inclined to want to do things for other people.

"It certainly stimulated me towards medicine."

This ethical perspective was enhanced, he said, by the words of Hillel in the Ethics of the Fathers, which he studied at Carmel around his barmitzvah: "If I am not for myself, who will be for me? But if I am only for myself, then who am I? And if not now, when?"

Dr Finlay lost no time in embarking on his medical career.

He studied medicine at Birmingham University where his ethical principles led him to become involved in the 1960's student rebellions.

He said: "I still remember the days when we took over the university chancellor's office. I'm not sure what we wanted. We said we wanted academic freedom, but I don't think we'd have known it if we saw it in the face."

After graduating in biochemistry, he took house jobs in Stoke-on-Trent, Birmingham and Manchester's Christie Hospital.

It was while he was a senior house officer at Birmingham's Children's Hospital, at the age of 29, that he developed testicular cancer. The following year, while at Christie's, he had a relapse with widespread metastatic disease.

He recalled: "My parents were ill at the time. Margot and I decided to keep the entire situation from my parents, who never did learn of it. Margot was the major source of my support and strength battling the disease.

"Without doubt surviving metastatic recurrent cancer has had a major impact upon my career."

Meanwhile Dr Finlay had fallen in love with America.

He said: "I had been to America in my first year of medical school and fallen in love with the country. I knew that it had what I wanted, academic freedom and flexibility, I knew that I had greater opportunities there than in the English system."

Marrying his first wife Diane, who was a professor of psychology, they settled in Madison, Wisconsin, where she was already working at the University of Wisconsin.

There Dr Finlay began to specialise in paediatric immunology and then paediatric oncology.

He took up his first post as an assistant professor at Stanford University, California, where he was recruited to run a research laboratory, as he had spent the last four years looking at how lymphocytes regulate cells in leukaemia and bone marrow failure.

He recalled: "When I walked through the door, I was told by my colleague that they divided up all the diseases.

"As the junior guy on the block, I was going to get the disease nobody else wanted. They gave me brain tumours."

That proved to be not only his lucky break, but also that of the thousands of young lives he came to save through his research.

He said: "I realised then, in 1980, what a huge black hole there was in brain tumour treatment."

In those days the most commonly prescribed method of treatment was radiotherapy.

But Dr Finlay discovered that radiation was bad for children's developing brains.

He said: "Brain cancer is the second most common cancer in children. But in 1980 very few children were cured of it and the quality of life of those who were was miserable as a result of the damaging effects of radiation on the developing brain.

"I made the decision to focus my career on brain tumours in children."

Moving back to Madison he began to focus on developing regional, then national and international brain tumour research programmes.

In 1987 he was recruited to the Children's Hospital, Philadelphia, two years later to Memorial Sloan-Kettering Cancer Centre, New York, then to the New York University Cancer Centre. For the last 10 years he has been at the Children's Hospital of Los Angeles.

Last year he gained an endowed chair in oncology and an endowed hospital-wide multi-disciplinary programme to further his research.

He said: "The brain tumour programme I have built up is the largest in terms of the numbers of children newly-diagnosed with brain cancer.

"I get children referred from all over America and indeed from elsewhere in the world. It is highly innovative in terms of new clinical research programmes."

Back in 1991 he established a treatment plan with 20 participating institutions, called Head Start.

He explained; "The federal government had a Head Start programme to give disadvantaged poor children a head start in life.

"I thought this would be a great title because we wanted to give very young children with malignant brain tumours a treatment plan to avoid radiation therapy completely."

His plan involved use of short intensive bouts of chemotherapy, including mega-dose therapy - a high dose of chemotherapy and a bone marrow transplant.

He said: "This does not leave the children with brain damage. Children come out truly cured and free of long term side-effects.

"Survival rates have improved dramatically. We are curing the most malignant tumours in young children.

"Where 20 years ago you could probably have cured 15 per cent with radiation, but with very severe side-effects, so that they couldn't function in society. Now about 70 per cent of our young children are cured."

But Dr Finlay is not resting on his laurels.

"We brag that we cure 85 per cent of kids with all kinds of cancer in England, Europe and North America," he said.

"We are talking about maybe 15 per cent of the world's children. What about the other 85 per cent?

"I'm not even thinking about darkest Africa, but Central and South America and South East Asia, societies that have a relatively good infrastructure in health care, but they don't even have the ability to achieve the same kind of cure rate that we do."

For the last decade he has been doing a lot of work in brain cancer in Central and South America.

He says: "I'm very keen on training people to go and work there."

In fact Dr Finlay's second wife, Adriana, comes from Brazil and he is very proud of the fact that last Pesach he catered a seder for all her non-Jewish family in their home town of Uberaba.

He said: "It was a wonderful experience. I always like to host my own seder and cook it every year.

"I have Shabbat dinner guests every now and again, with kiddush and birchat hamazon.

"My wife loves to join in zemirot. I join my cousin in his succah every year and go to Chabad for the high holidays."

Every time Dr Finlay visits England for conferences, he makes a point of spending time with his beloved sister Margot and her family.