Liver cancer incidence has tripled in Canadian men and doubled in women since the 1970s, the Canadian Cancer Society says.
The death rate for all cancers combined has been declining for males in most age groups and for females in all age groups except over 70, the society said in releasing its annual cancer statistics Wednesday.
Overall, the society estimates 187,600 people in Canada will learn they have a new cancer this year (excluding non-melanoma skin cancers). About 75,500 Canadians will die from some form of malignancy.
This year, the society focused on liver cancer, which it called one of the fastest rising types of cancer, and one with a poor prognosis. Of those diagnosed with it, four of five will die within five years, compared with people of the same age in the general population who don't have cancer.
Primary liver cancer that hasn't spread from another site to the organ is still rare. About 2,000 new cases of liver cancer are expected this year with about 1,000 deaths from the disease.
"This is the only cancer in Canada for which mortality is actually increasing," said Dr. Morris Sherman, a liver specialist at Toronto General Hospital and chair of the Canadian Liver Foundation.
The greatest risk factors for liver cancer are chronic hepatitis B and hepatitis C infections, but the viruses aren't well-recognized as health threats, the society said.
Since 1970, the incidence of liver cancer has tripled in Canadian men and doubled in women, rising every year by 3.6 per cent in men and 1.7 per cent in women.
"One of the problems with this disease is that it does not develop symptoms or patients aren't aware that they have the problem until the disease is very advanced, at a very large and untreatable stage," Dr. Sean Cleary, a surgical oncologist at Toronto's University Health Network.
Test and treat infections
Treatment for liver cancer can involve surgery, chemotherapy, radiation and radiofrequency ablation — heating where the cancer is to treat it, if the blemishes are detected early by ultrasound.
Radiofrequency ablation is a day procedure that is cheap compared with chemotherapy and has a high survival rate, said Dr. David Wong of Toronto Western Hospital's Liver Centre.
"When it is small, under an inch or 2.5 centimetres, it is relatively easily curable," said Wong.
But, he said, a lack of resources and beds can delay treatment.
"Even though we find these cancers, sometimes we have to wait and watch them grow while the hospitals find the slots to treat them," Wong said.
To lower rates, the society said, it's important to find and treat people with hepatitis B or C.
There is currently a vaccine against hepatitis B but not for hepatitis C, which accounts for about 30 per cent to 50 per cent of liver cancer cases in North America, the society said.
The Canadian Cancer Society also encouraged primary health-care providers to offer hep B vaccination or testing to those at risk, including newcomers to Canada if they come from parts of the world where hepatitis infections or liver cancer are common.
Other risk factors for liver cancer include:
- Heavy alcohol use.
Last year, the U.S. Centers for Disease Control urged all baby boomers to have a one-time test for hepatitis C.
The Canadian Liver Foundation recommends a hepatitis C test for those born between 1945 and 1975.
The Public Health Agency of Canada is studying whether it makes sense to issue a similar recommendation in Canada, saying the rate of hepatitis C is lower than in the U.S.
"The epidemiology of hepatitis C and the estimated proportion of people unaware of their hepatitis C infection are different in Canada (21 per cent) than in the U.S. (50-75 per cent)," a spokesperson for the Public Health Agency of Canada said in an email.
"In Canada, current guidance on testing for hepatitis C is based on risk criteria, such as an injection drug use history, incarceration, born/travelled/resided in an endemic region, blood transfusion before 1992 in Canada."
In general, rates of deaths from new cancers are stabilizing and declining, the Canadian Cancer Society said. The number of new cancer cases and deaths are rising as the population grows and ages.
Four types of cancer — lung, breast, colorectal and prostate — accounted for 52 per cent of newly diagnosed types of the disease.
The report was prepared in collaboration with the Public Health Agency of Canada, Statistics Canada and provincial and territorial cancer registeries.