About Liver Cancer

What is liver cancer?

Cancer in the liver can arise from the liver itself or originate from another organ and then spread to the liver. Liver cancer that forms directly in the liver is known as primary liver cancer. There are 2 main types of primary liver cancer: hepatocellular carcinoma (HCC) and cholangiocarcinoma.

 

The most common form of liver cancer in adults is known as hepatocellular cancer (HCC) which arises from hepatocytes (liver cells) while cells forming the ducts leading to the gall bladder and intestine can mutate into the cancerous cholangiocarcinoma.

 

Most cases of HCC develop due to viral infection (hepatitis B or C) or cirrhosis. Cirrhosis is scarring of the liver with resulting poor liver function as a result of chronic liver disease. Causes can also include alcohol abuse over a long period of time. HCC may be difficult to detect in its early stages as symptoms do not appear until the cancer has progressed to a more advanced stage.

 

Another type of liver cancer is metastatic liver disease (cancer) or secondary liver cancer. This kind of liver cancer arises when the main cancer, which originates in other parts of the body, spreads to the liver.

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Causes / Risk Factors Some of the risk factors for Hepatocellular Carcinoma are:

  • Chronic infection with hepatitis B & C viruses
  • Alcohol abuse leading to liver cirrhosis
  • Ingestion of aflatoxin, which is a toxic substance produced by certain forms of mold which can infect peanuts, other nuts, cereals and spices
  • Hemochromatosis, a disorder in which there is too much iron stored in the body, including in the liver
  • Diabetes and obesity

 

Possible Symptoms

Some of the symptoms that may be experienced are:

  • Pain / discomfort in the upper abdomen on the right side
  • A hard lump in the upper abdomen on the right side
  • Swollen abdomen (bloating)
  • Loss of appetite
  • Weight loss
  • Tiredness / Weakness
  • Nausea and vomiting
  • Jaundice - yellowish staining of the skin and sclerae (the whites of the eyes)

 

Diagnosis

You may have one or more of the following carried out:

  • Physical exam: The abdomen may be checked for any lumps present or ascites, an abnormal build-up of fluid in the abdomen.
  • Blood tests: To test for tumour markers and liver function. E.g.: Test for alpha-fetoprotein (AFP), a tumour marker for HCC. High levels of AFP could indicate the presence of HCC.
  • CT scan (CAT scan): To take a series of detailed pictures of the abdomen (including liver) to detect presence of tumours using a computer linked to an x-ray machine
  • MRI (Magnetic Resonance Imaging): To take a series of detailed pictures of the abdomen (including liver) to detect presence of tumours using a computer linked to an machine with a strong magnet
  • Ultrasound test: Using echoes resulting from sound waves that bounced off internal organs to create a picture of your liver and other organs in the abdomen.
  • Biopsy: To remove a sample of liver tissue through small incisions to the abdomen. The sample tissue is to be viewed under a microscope by a pathologist to check for presence of cancer cells. Biopsy is usually not necessary for diagnosis of HCC as modern imaging allows accurate diagnosis.

 

Treatment

There are a couple of treatment options for liver cancer.

Surgery remains the best effective means of treating liver cancer. It involves removing all the cancer that the surgeon can find, guided by the investigation results and imaging studies. However as symptoms do usually not appear until the cancer has progressed to an advanced stage resulting in late diagnosis, most patients with HCC have tumours that make them unsuitable for surgery.

Complete removal may not be possible if the tumour is too big or if the tumours can be found in multiple sites in the liver. Moreover, patients with cirrhosis are considered eligible for surgery only if their liver function is adequate. Liver transplant can also be useful for selected patients with cancer that is small but with liver function too poor to allow safe resection. The patient must also fulfil other strict criteria that ascertain that transplantation is useful for prolonging the life of the patient. Access to this alternative is limited by donor availability.

In chemotherapy, anticancer drugs reach all parts of the body. This makes the treatment potentially useful for cancers that have spread to other organs. Currently the only drug proven to make liver cancer patients survive longer is the drug sorafenib. (see small molecular targeted therapy below).

 

The use of radiation therapy is an option for patients who are unable to have surgery. Radiation is usually delivered as selective internal radiation therapy (SIRT). In this procedure, tiny radioactive spheres are injected into the hepatic artery where the radioactive spheres travel to the tumours and kill the cancer cells with its radiation emission. One such example is Sir-Spheres, which has shown to be well tolerated and effective for selected patients with unresectable HCC.

 

 drugs

In embolization/ chemoembolization, the doctor injects particles or anticancer drugs into the hepatic artery to block the flow of blood to the tumour cells and at the same time, kills the tumour cells. It is a widely used therapy when surgery is not possible. An example would be Trans-catheter Arterial Chemo-Embolisation. Clinical trials have demonstrated encouraging rates of tumour shrinkage and the therapy is usually well tolerated if cirrhosis is not severe.

New treatment options, such as small molecule targeted therapy, have been developed to treat liver cancer. Small molecules are designed to block certain key functions of the cancer cells, thus stopping them from growing. An example of such a drug is Sorafenib. It has been established as the standard treatment for metastatic advanced HCC. Currently, Sorafenib offers the best option for patients whose cancer is no longer responding satisfactorily to other forms of therapy.

 

References

  1. Omata M, Lesmana LA, Tateishi R, Chen PJ, Lin SM, Yoshida H, Kudo M, Lee JM, Choi BI, Poon RT, Shiina S, Cheng AL, Jia JD, Obi S, Han KH, Jafri W, Chow P, Lim SG, Chawla YK, Budihusodo U, Gani RA, Lesmana CR, Putranto TA, Liaw YF, Sarin SK. Asian Pacific Association for the Study of the Liver consensus recommendations on hepatocellular carcinoma. Hepatol Int 2010;4:439-74.
  2. Kulik LM, Carr BI, Mulcahy MF, et al. Safety and efficacy of 90Y radiotherapy for hepatocellular carcinoma with and without portal vein thrombosis. Hepatology 2008;47:71–81.
  3. Low SC, Lo RH, Lau TN, Ooi LL, Ho CK, Tan BS, Chung AY, Koo WH, Chow PK. Image-guided radiofrequency ablation of liver malignancies: experience at Singapore General Hospital. Ann Acad Med Singapore 2006;35:851-7.
  4. Lim KC, Chow PK, Allen JC, Chia GS, Lim M, Cheow PC, Chung AY, Ooi LL, Tan SB. Microvascular invasion is a better predictor of tumour recurrence and overall survival following surgical resection for HCC compared to the Milan criteria. Annals of Surgery 2011; [Epub ahead of print].
  5. Samuel M, Chow PK, Chan Shih-Yen E, Machin D, Soo KC. Neoadjuvant and adjuvant therapy for surgical resection of hepatocellular carcinoma. Cochrane Database Syst Rev 2009:CD001199.

Useful Links

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