TORONTO -- Lung cancer kills more Canadians each year than any other malignancy, but the disease receives a disproportionate amount of research and donation dollars compared with far less deadly cancers, says a national advocacy organization.

Lung Cancer Canada says the disease causes more than 28 per cent of Canadian cancer deaths -- more than those from breast, colon and prostate cancer combined -- but receives only seven per cent of cancer-specific research funding and 0.1 per cent of charitable cancer donations.

Dr. Natasha Leighl, an oncologist at the Princess Margaret Cancer Centre in Toronto, said the reason lung cancer gets so little respect is the stigma surrounding tobacco use -- and the mistaken belief that all cases of lung cancer result from smoking.

But Leighl said at least 15 per cent of people who get lung cancer never smoked and some develop it through exposure to radon gas or industry-related carcinogens like asbestos. And recently, the World Health Organization fingered air pollution as a major cause of lung cancer.

"As someone who works in this area, I'm always so surprised that Canadians are so supportive of other smoking-related diseases like heart disease and stroke, and yet lung cancer seems to bear all the blame associated with smoking," she said Thursday.

"I think it's important to realize that a growing number of people with lung cancer are people who smoked as teenagers and then quit when they were very young. There's a growing number of never-smokers with this disease, and this is something that really affects all Canadians and is definitely worth people supporting, irrespective of the smoking issue."

In fact, one in 12 Canadians is at risk for lung cancer in their lifetime -- both smokers and never-smokers alike, said Leighl, who is also president of Lung Cancer Canada.

About 25,000 Canadians are diagnosed annually with lung cancer and an estimated 20,000 die each year from the disease, said the organization, which is calling for a national screening program, increased research funding and greater access to new life-prolonging drugs.

Dr. Peter Ellis, an oncologist at McMaster University's Juravinski Cancer Centre, said that despite the grim toll taken on women by lung cancer, the disease "isn't even recognized" in fundraising events like the annual Weekend to End Women's Cancers.

"We need to change that," Ellis told a briefing on the state of lung cancer in Canada on Thursday.

Other cancers, among them colon and breast cancer, are influenced by lifestyle choices such as poor diet and lack of exercise, but patients with those malignancies aren't typically exposed to the stigma attached to lung cancer.

Indeed, those dealing with lung cancer say they often feel isolated because of people's reactions to their diagnosis. Typically, they say, it begins with: "Oh, I never knew you smoked!"

Roz Brodsky was diagnosed with lung cancer in 2004 at age 45, not long after she had quit smoking. Like many in her generation, she said she started smoking as a teen because she thought it was "glamorous" and she got hooked.

When some people learned she had lung cancer, they either "recoiled with horror or asked 'Do you smoke?"' instead of asking if she was OK, said Brodsky of Thornhill, Ont.

She said she found it difficult, in a society where women with breast cancer get so much support with numerous pink-ribbon fundraising efforts, that there was not even a support group for people with lung cancer in a city as large as Toronto.

Now 55 and cancer-free, Brodsky said she worries about young people who have never smoked mistakenly believing they have no risk of lung cancer because of its connection with smoking.

"The way lung cancer is portrayed ... it lulls non-smokers into a false sense of security."

Despite lung cancer's lack of clout in the fundraising arena, Leighl said doctors and researchers are making strides forward in earlier diagnosis and treatment.

The five-year survival rate has risen to 18 per cent from about 14 per cent a decade ago, and there have been a number of breakthroughs in understanding what drives the development of lung cancer at the molecular level.

That's led to new drugs, such as Tarceva, which target genetic abnormalities within cancer cells. Other drugs, which are in clinical trials but available for doctors to prescribe, act to help the immune system recognize and kill cancer cells.

"This is not chemotherapy," Leighl said of the immune-based therapy. "You don't lose your hair, you don't get sick to your stomach. This is really about harnessing the immune system and its ability to kill cancer.

"We've seen dramatic (tumour) shrinkages in patients with lung cancer. I've had patients who've been on those treatments for more than a year. They've been chemotherapy-free where even last year I would have had to put them on chemotherapy. That would have been the standard.

"So there's a lot of excitement and potential promise."

Lung Cancer Canada wants a national program to screen people with the highest risk of lung cancer, using low-dose computerized tomography, or CT, scans for earlier detection of the disease.

An estimated 1,250 lives could be saved each year with such screening and pilot programs need to be set up by all provinces, so Canadians across the country have access to them, Leighl said.

"This is something the government needs to move on quickly."