The liver is one of the largest organs in the body. It is located under the diaphragm in the right upper abdominal cavity and performs many important functions, such as manufacturing various essential proteins, processing and storing nutrients, destroying toxins and poisons.
Normal cells divide and reproduce in an orderly manner. Your body relies on this orderly activity to repair injuries and replace worn-out cells. Sometimes this orderly process is disturbed. This can be due to mutations in the genes of cells. Mutations in the liver can be caused by chronic inflammation due to viruses (hepatitis B and C), toxins (alcohol, alfa-toxins) and metabolic injuries (non-alcoholic fatty liver disease (NAFLD), steatohepatitis (NASH)).
When cells grow and divide out of control, extra tissue is formed creating a mass or lump called a tumour. Tumours can be benign or malignant. Benign tumours are not cancers as they grow slowly and do not spread to other parts of the body.
Malignant tumours are cancerous growths which have the potential to spread to other parts of the body. Malignant liver tumours can be primary or secondary.
Primary liver cancer or hepatocellular carcinoma (HCC) originates in the liver.
HCC is the 4th most common cancer among men in Singapore, and it more commonly occurs in those aged above 50 years of age. Liver cancer is also mainly an Asian disease, and is prevalent in South-East Asia, China, Japan and Korea.
Metastatic or secondary liver cancer occurs when cancer that originates elsewhere in the body spreads to the liver. The most common type of metastatic liver tumours is caused by colon cancer that has spread to the liver.
Note: The information here on Liver Cancer will focus on hepatocellular carcinoma (HCC), which is the most common type of primary liver cancer.
In most patients with HCC, the most common type of primary liver cancer, there are often no symptoms even when the tumour has grown large. As the cancer advances, some symptoms may show. These include:
When to see a doctor
Make an appointment with your doctor if you experience any signs or symptoms that worry you.
You can reduce your risk of hepatitis B by receiving the hepatitis B vaccine. Vaccines for hepatitis B are available for children and adults. Children should get hepatitis B immunisation at birth as part of the Singapore National Childhood Immunisation Schedule. There is currently no vaccine for hepatitis C.
Family members of patients with hepatitis B are advised to check their own hepatitis B status.
If you are at risk for hepatitis B or C infection, consider undergoing a screening test.
Those with chronic hepatitis B or C should also visit their doctors for regular surveillance with imaging tests, such as ultrasound. If you have chronic hepatitis B or C, you might be a candidate for antiviral therapy, which can slow down the progression of liver disease and may decrease, but not totally eliminate the risk of liver cancer.
You can lower your risk of developing liver cancer by leading a healthy lifestyle - exercise regularly, control your weight and eat a healthy balanced diet.
Chronic alcohol use is a risk factor and can lead to liver cirrhosis, which increases the risk of liver cancer. The Health Promotion Board recommends no more than two standard drinks a day for men, and no more than one standard drink a day for women.
Screening is advised for high-risk individuals with liver cirrhosis or chronic hepatitis B infection. Regular screening may involve blood tests for alpha-fetoprotein (AFP) and liver function assessments every 3 months, as well as ultrasound scans of the liver every 6 months.
People with risk factors are more likely to develop primary liver cancer or HCC. The more risk factors a person has, the greater the chance that liver cancer will develop. However, many people with known risk factors do not develop the disease.
If you think you may be at risk for liver cancer, discuss it with your doctor to see how to manage your risk.
Factors that increase the risk of primary liver cancer:
Current gold standard for diagnosing primary liver cancer is through multi-phasic imaging with CT scans or MRI scans.
In high-risk patients, regular screening is carried out using abdominal ultrasound and a blood test for serum alpha-feto protein (AFP), which is a cancer marker. If either the ultrasound or serum AFP is abnormal, then a CT scan or MRI scan would be done to confirm the diagnosis.
While hepatocellular carcinoma (HCC), a common type of primary liver cancer is the third most fatal cancer in Singapore, early-stage liver cancers are responsive to treatment with either surgery or ablation techniques. The chance of survival for individuals with early-stage liver cancers beyond 5 years is more than 40%.
Treatment for primary liver cancer should be individualised to each patient and depends on:
An individual with cancer should be assessed by a specialist to determine which modality of treatment is best suited for them.
Liver cancer surgery
Surgery offers the best chance for cure and long-term survival for primary liver cancer. It can be in the form of resection, where the part of the liver with the cancer is removed, or a liver transplant. Unlike many other organs where complete removal of the organ (such as both breasts, the entire colon or stomach) is possible, a person cannot live without a liver. Resection is undertaken when complete removal of the cancer is feasible and yet leaves enough liver intact for the patient’s needs.
In cases where there are multiple cancer nodules, the cancer is recurrent or the underlying liver disease is advanced, a liver transplant may be recommended. A donor liver can be from a cadaveric donor or from a healthy individual who is willing to donate part of their liver (i.e. a living donor). If a liver transplant is recommended, a series of tests and medical assessments will be carried out to assess if the patient is fit to undergo a liver transplant.
Following a liver transplant, the patient will need to take immunosuppression drugs for life to prevent organ rejection.
Localised chemotherapy and radiotherapy
Localised chemotherapy and radiotherapy treatments are done when surgery is not possible.
Localised chemotherapy involves delivery of chemotherapy directly to the liver cancer via a tube inserted at the groin. This has the advantage of delivering a higher dose of chemotherapy to the cancer, while minimising side effects to the rest of the body.
Localised radiotherapy with yttrium 90, is similar to localised chemotherapy. It involves delivering radioactive materials directly to the liver cancer via a tube inserted at the groin. A series of tests is performed before administering this form of treatment to determine if a patient is suitable.
Ablation techniques are suitable for small cancers measuring less than 3cm in size. The efficacy of ablation in small cancers is close to that achieved with surgery. The most common form of ablation technique is Radiofrequency Ablation (RFA). This involves inserting a thin rod through the liver into the cancer and using radiofrequency to generate heat, which kills the cancer cells.
Microwave is another source of energy used for ablation. Access of the rod to the cancer can be via the skin and is guided by ultrasound or CT scan. In this situation, general anaesthesia may not be necessary. General anaesthesia is required if access of the rod is directly into the liver via open or laparoscopic (keyhole) surgery.
Systemic treatment is undertaken in advanced cases where other treatment options are not suitable. Sorafenib, which is taken daily as an oral medication, is the most commonly prescribed systemic treatment. Intravenous chemotherapy may be given in selected cases.
In advanced cancer cases where all the above treatment options are not suitable, participation in a suitable clinical trial may be suggested. Clinical trials aim to determine if new treatment medication is effective in controlling the disease.
When treatment is not possible or is ineffective, palliative care can help to ease symptoms such as pain, ascites (collection of fluid in the peritoneal cavity that can cause breathlessness and discomfort) and jaundice (which causes the skin to turn yellow and feel itchy).
Palliative care, also increasingly known as supportive care, is a holistic approach to caring for anyone diagnosed with a serious illness such as cancer, to allow them to live as well as they can, for as long as they can. Palliative and supportive care is specialised support provided by a multi-disciplinary team of doctors, nurses, clinical psychologists, medical social workers and other allied health professionals to help patients.
Before surgery, your surgeon will perform comprehensive medical assessments including blood tests and scans to see if you are suitable for surgery and advise on the risks involved. Your treatment recommendation is often based on consensus by a group of medical specialists' opinions (the tumour board), who come together to discuss the pros and cons of every treatment strategy.
Before surgery, the anaesthesia team will assess your fitness for surgery and advise you on various aspects of general anaesthesia and pain control after surgery.
Specialist nurses will also provide pre-surgery counselling so that you know what to expect.
After surgery, you will be given regular outpatient appointments to see your team of doctors. During these appointments you may have blood test and scans to check if the cancer recurs.
It is important to follow your doctor's advice, keep to your clinic visits and do the recommended scans and tests, so that timely treatment can be administered if the cancer recurs or other problems occur.