Hepatitis and alcoholic sclerosis are the main causes
Q&A with Anthony Chan Tak-cheung, chairman of the Department of Clinical Oncology, Chinese University of Hong Kong
What are some of the common causes of liver cancer? The three main causes of liver cancer are hepatitis B, which accounts for at least 70 per cent of liver cancer cases, hepatitis C and alcoholic sclerosis. While hepatitis C and alcoholic sclerosis are predominantly seen in western countries, hepatitis B is much more prevalent in the Asian and African regions, with 10 per cent of the population still serving as carriers. However, due to the hepatitis B vaccinations that started in the late '80s, these numbers are expected to decrease in the coming years.
How does alcohol affect our risk of liver cancer? While alcohol cannot be said to directly cause liver cancer, high alcohol consumption may certainly expose our livers to damage, which in turn leaves us vulnerable to cancer. Cells in our body are controlled by our genes, and when this genetic control is deregulated by either hepatitis or excessive alcohol consumption, these cells are then said to be 'out of control', and our bodies are subsequently predisposed to a higher risk of contracting liver cancer.
What is a safe level of alcohol consumption? While there is no absolute standard, it is generally agreed that one drink a day is considered a safe amount of alcohol consumption. This obviously varies between individuals of different age and gender, so personal judgment must be exercised.
Are there other dietary factors that affect our risk of liver cancer? In terms of conclusive effects, nothing can be shown to be in the same league as alcohol.
Is liver cancer more common in men or women? Why is that the case? Research has shown that men are three times more likely to contract liver cancer. Men are generally more susceptible to cancer, while women seem to have more protection, a phenomenon due in part to their genetic makeup.
How do genetics play a part in liver cancer? While we know that genetics play a part, we still don't have enough information to definitively claim that a specific gene has a direct relationship to liver cancer. Rather, liver cancer usually results from multiple genetic changes and several other factors, such as hepatitis or alcoholic sclerosis. Hepatitis B may sometimes be passed on through vertical transmission, a process that carries the disease from the mother to the child through the course of childbirth.
There have been cases where people were struck with liver cancer, despite the fact that they maintain seemingly healthy lifestyles, and don't drink or smoke. Are there 'hidden factors' that may have led to these cancer cases? Sporadic cases of cancer may indeed occur in people who lead healthy lifestyles. In some cases, we may attribute this to their genetic makeup or some other underlying factor. However, the risk of liver cancer remains small for people who don't have alcoholic sclerosis and who aren't carriers of hepatitis.
What treatment is available to those who have contracted liver cancer? For those who seek treatment in the early stages, when the liver functions are still good and well-preserved, surgery is the best option. However, 85 per cent of those who seek treatment come during the later stages, when the liver is no longer operable. At this point the patient may choose between a liver transplant, ultrasound treatment, regional treatment, or drug treatment. Understandably, due to the limited number of donors, only a small number of patients have the option of conducting a liver transplant. Regional treatment, conducted through the femoral artery or groin, is the more common option. Drug treatments such as chemotherapy and targeted drug treatments can also be conducted with varying effects. Chemotherapy kills a large number of cancer cells, but also destroys healthy cells in the process, while targeted drug treatment targets specific, known cancer cells. Doctors often use a combination of both to ensure that the cancer cells have been completely eradicated from the body. The ultrasound treatment, which utilises a probe, is a very direct treatment, but only works on smaller tumours.
