At the time Terry Fox was treated for the bone cancer that claimed his leg and eventually led to his death in 1981, few patients survived that kind of malignancy, known as an osteosarcoma.

But advances in treatment over the last few decades have dramatically altered that grim prognosis, with the majority of patients today not only keeping their limbs, but many also surviving the cancer.

When the B.C. 18-year-old was diagnosed with osteosarcoma in his right leg in 1977, doctors immediately amputated the limb above the knee — the standard treatment then — and he embarked on a 16-month marathon of chemotherapy, a drug regimen for this kind of bone cancer that was still somewhat experimental at the time.

For many Canadians, the heroic runner's name has become synonymous with osteosarcoma, the most common form of primary bone cancer to affect children and teens, and one that also occurs rarely in older adults.

"And that's always a good and bad analogy because they know who he is but that he had his leg cut off and died — and that's not the typical scenario now," says Dr. Jay Wunder, an orthopedic surgeon at Mount Sinai in Toronto who specializes in sarcomas.

Cure rate up to 80 per cent

"Most bone sarcoma patients now don't have amputations. Most get limb-sparing or limb-reconstructive surgery," says Wunder. "Now the cure rate's almost up to 80 per cent in younger patients. In older patients it's more like 70 per cent.

"So that's a pretty big turnaround in a couple of decades."

Dr. Jay Wunder, surgeon and chief at Mount Sinai Hospital in Toronto, pulls a tower of sarcoma specimens used for cancer genetics research from a freezer of liquid nitrogen. (THE CANADIAN PRESS/Darren Calabrese)

When Dave Lambert, 63, was diagnosed with sarcoma in his left knee almost two years ago, he was initially unaware of the connection to Fox, nor that the path he would follow had been made so much easier by the determined teen who set out in 1980 to run across Canada to raise money for cancer research.

The businessman from Aurora, Ont., just north of Toronto, had developed a bump on his left knee, which rapidly grew into a large mass and burst open when he tripped and fell.

His doctor told him a biopsy had confirmed it was a sarcoma.

"He just looked at me and said, 'Remember Terry Fox?"'

"I'm an older man and when I was growing up anybody who had cancer, they just died," says Lambert. "And when you heard the word 'Terry Fox,' the immediate vision I remember, all that flashed in front of my face, was Terry Fox losing his leg and I could picture him running and then being dead. That's all I thought of when he said that word to me and then I just went into shock, total shock."

But during a referral appointment with Wunder the following week, Lambert learned his cancer was no longer considered an automatic death sentence.

Bone cancer no longer means losing limbs

Surgery did not mean losing part of his leg; instead the tumour was removed and tissues in and around the joint were reconstructed.

"It was a very humbling experience," says Lambert, who was up walking within weeks of the operation and says his knee "looks great."

Dr. Jay Wunder, surgeon and chief at Mount Sinai Hospital in Toronto, is surrounded by liquid nitrogen vapour in the hospital's Biospecimen Repository and Processing Lab on Wednesday, September 10, 2014. (THE CANADIAN PRESS/Darren Calabrese)

While much progress has been made in treating osteosarcoma, there is still much work needed to advance treatment for most of the 50 or so other sarcomas, which in overall cancer terms are still considered rare.

Sarcomas are tumours that arise in connective tissues, such as bone. But most types develop in soft tissues like muscle, nerves, skin, fat and blood vessels. The cancer can spread to other parts of the body, such as the lungs, which occurred in Fox's case and ended his Marathon of Hope on Sept. 1, 1980 just outside Thunder Bay, Ont.

"They're harder to treat," Wunder says of soft-tissue sarcomas. "If we do good local surgery for those patients, we can cure a fair percentage, but a lot of those patients relapse and there's no effective curative chemotherapy for them."

"In fact, if we had effective chemo, (these tumours) would probably be transformed the way osteosarcoma was and we could treat those people very differently."

Other types of sarcoma still deadly

In 2010, 1,175 Canadians were diagnosed with soft-tissue sarcoma; about 470 died of the disease in 2009, according to the Canadian Cancer Society, citing the most recent years for which statistics are available.

The cause of sarcoma is unknown, although genetics may make some people more susceptible to the cancer. Various research groups around the world are investigating whether aberrant stem cells might give rise to these tumours, but that still to be determined.

Dr. Jay Wunder, surgeon and chief at Mount Sinai Hospital in Toronto, pulls a tower of sarcoma specimens used for cancer genetics research from a freezer of liquid nitrogen. September 10, 2014. (THE CANADIAN PRESS/Darren Calabrese)

Much of the research focus is on finding new drugs to treat various types of sarcomas, and there has been modest progress in that area. For instance, a once "uniformly fatal" abdominal sarcoma called GIST, is now being treated with a molecular drug that specifically targets a genetic mutation found in these tumours, leading to "an overnight change in outcome," says Wunder.

His colleague at Mount Sinai and the Princess Margaret Cancer Centre, oncologist Dr. Albiruni Razak, says before the drug's discovery, GIST patients had an average life expectancy of nine months; survival for some patients now is measured in years, and for some it can be as long as 15 years.

Drug development is a key goal of the sarcoma research team at Mount Sinai, which includes genetic studies using samples of patients' cancerous tissues that are frozen and stored in the hospital's tumour bank — a collection of innocuous-looking metal containers.

"This is the whole critical path of the future, because if you don't do this, you can never improve anything," Wunder says of storing tumours for study.

Cell lines grown in the lab from tumour samples are used to look for potentially effective drugs. Tiny quantities of the cells are put in "dishes," then mixed with candidate drugs by robotic equipment in a so-called high-throughput lab at the hospital. The technology can test thousands of compounds at one time.

"That's kind of a needle-in-a-haystack thing, but we have the opportunity, we have the tissue, and so if you don't try you never know," he says. "And lots of new drugs get found that way. For cancer especially, it's amazing how often people are finding new, potentially active drugs through that."

Terry Fox's legacy

Razak says chemotherapy has for many years been given using a "blunderbuss approach," trying different combinations in the hope of killing a patient's cancer.

That's increasingly giving way to a more focused strategy, called personalized medicine, in which oncologists hope to match particular drugs to an individual, based on their genetic profile or that of their tumour.

Terry Fox running his Marathon of Hope. Since his death in 1981, Fox has raised $650 million in the fight against cancer. (CBC)

"Another way to look at it is to try to individualize per person, not to individualize per disease," he says.

"The whole idea that just because you have sarcoma ... we give you a standard chemo, that approach is not scientific enough now."

Lambert attributes his survival to Fox, and the scientific advances spurred by the millions of dollars raised by his marathon and the annual events run in his name.

"If they could really understand the true good this money has gone to achieve. I'm walking now. I have my leg now. I'm alive now because of people like Terry Fox and the people who have supported the Terry Fox run over the years.

"Without that, I'm not here."

On Sunday, an estimated 200,000 Canadians will join Terry Fox runs in almost 800 communities across the country, and an estimated three million participants will take part in runs hosted by 9,400 schools throughout September.

Since Fox began his Marathon of Hope, $650 million has been raised in the fight against cancer.