Liver cancer is to blame for more than a thousand deaths every year in Ontario — and most of these occur in the Greater Toronto Area. In fact, the epidemic level of liver cancer in this city often goes unrecognized, as it’s diluted by provincial and national statistics.
So what is it about Toronto that makes it such a hot spot for this type of cancer?
Most of the cases occur in patients with chronic liver disease, typically due to chronic blood-borne infections with the hepatitis B or C viruses.
The transmission of hepatitis B occurs mainly from mother to child and is prevalent in several regions of the world. Immigrants from East Asian and African communities are at an especially elevated risk of carrying hepatitis B, and of developing liver cancer. Hepatitis C is found throughout the world and mainly spread through sharing and inadequate sterilization of needles and syringes. Those who’ve been exposed to infected blood are also at a higher risk — and adults born between 1945 and 1975 are much more likely to have been exposed to hepatitis C. Both infections are silent, with no symptoms until it is too late.
And it’s a big issue: liver cancer is among the most fatal cancers in the province — now the fifth most common cause of cancer death among men in Ontario. This is new for North America, where it has traditionally been uncommon (globally it’s the second most common cause of death from cancer).
But with the undetected spread of hepatitis C and a growing immigrant population, Ontario has seen a staggering 4.5 per cent increase every year for the past 30 years. Today, the province’s rate of new cases is similar to regions with moderately high incidence, such as Western Africa. But because of the concentration of immigrants in Toronto, our local rate is even higher. If you live in this city, there is a real chance you may be at risk.
The survival rate from liver cancer has tripled over the past 30 years but it remains quite low. According to provincial statistics, only 24 per cent of patients will survive five years or longer. But when caught early, there is a high chance of cure.
New advances in our knowledge and treatments make prevention and cure possible. For instance, effective treatments have recently been developed for chronic viral hepatitis resulting in diminishing incidence of liver cancer in those successfully treated. And in our work at the University Health Network, we have found that three quarters of cancers found in patients undergoing regular ultrasound checks were within a potentially curable stage. Furthermore, our research has shown that ultrasound scans have resulted in improved liver cancer survival rates in Ontario.
However, only half of cancers detected elsewhere in the GTA are potentially curable, likely because they have had no or too little surveillance. With few symptoms until too late, liver cancer is all too often found when in an advanced, incurable stage leading to our poor provincial survival statistics. As a physician, it’s disheartening to see so many middle-aged patients appear week after week with new large, invasive tumours that should be a rarity given our advanced health care system.
Who’s at risk?
Liver cancer occurs in patients with chronic hepatitis or liver disease — so finding out if you’ve been infected is the first step. If you don’t know your hepatitis infection status, ask your family doctor if you need to be checked. And if you carry the infection, see a liver specialist for possible treatments.
- Hepatitis B: The highest rates of infection are seen in immigrants from East Asian and sub-Saharan African communities. Also at higher risk are members of South Asian, Middle Eastern, and southern aspects of Central and East European communities.
- Hepatitis C: Adults born between 1945 and 1975 are up to five times more likely to have been exposed to hepatitis C than other adults. Liver experts and the Canadian Liver Foundation have advocated a one-time screening for hepatitis C for all members of this age group, even those born in Canada. Hepatitis C is present throughout most of the world. Therefore if you are an immigrant from anywhere outside northern Europe, you are at higher risk and should consider getting tested, especially since curative treatments have recently been developed. Particularly at high risk are immigrants from Central and East Asia, and Africa.
- If you have developed cirrhosis (scarring of the liver) or are a chronic hepatitis B carrier, you’re at risk of liver cancer, and should be getting liver ultrasound scans every six months.
Dr. Korosh Khalili is an associate professor in the University of Toronto’s Department of Medical Imaging, radiologist at the Joint Department of Medical Imaging, at the University Health Network, Sinai Health System, and Women’s College Hospital, and a master’s student in the U of T Faculty of Medicine’s Translational Research Program. Dr. Morris Sherman is the chairman of the Canadian Liver Foundation, a professor in the University of Toronto and a liver specialist at University Health Network. Dr. Hla-Hla Thein is a scientist in the University of Toronto’s Dalla Lana School of Public Health. Doctors’ Notes is a weekly column by members of the U of T Faculty of Medicine. Email doctorsnotes@thestar.ca .
Dr. Korosh Khalili is an associate professor in the University of Toronto’s Department of Medical Imaging, radiologist at the Joint Department of Medical Imaging, at the University Health Network, Sinai Health System, and Women’s College Hospital, and a master’s student in the U of T Faculty of Medicine’s Translational Research Program. Dr. Morris Sherman is the chairman of the Canadian Liver Foundation, a professor in the University of Toronto and a liver specialist at University Health Network. Dr. Hla-Hla Thein is a scientist in the University of Toronto’s Dalla Lana School of Public Health. Doctors’ Notes is a weekly column by members of the U of T Faculty of Medicine. Email doctorsnotes@thestar.ca .
The Toronto Star and thestar.com, each property of Toronto Star Newspapers Limited, One Yonge Street, 4th Floor, Toronto, ON, M5E 1E6. You can unsubscribe at any time. Please contact us or see our privacy policy for more information.
Our editors found this article on this site using Google and regenerated it for our readers.
