Primary Liver Cancer: an Overview

The liver is not only one of the largest organs in the body but it is also its de facto chemical factory indispensable for life and responsible for processing all the nutrients (proteins, carbohydrates and fats) absorbed from the gut. Some of the liver vital functions include filtering blood as it passes through the body, producing bile to break down and digest fats, storing glycogen or sugar to later be used for energy, producing essential proteins such as albumin that transport important elements in the blood, and manufacturing clotting factors to allow the blood to coagulate.

When malignant cells form within the liver, one of two forms of primary liver cancer can develop depending on the cells where the cancer originates: the most common hepatocellular carcinoma which occurs in 90% of the cases and much rarer intrahepatic cholangiocarcinoma. The incidence of primary liver cancer has been steadily increasing over the past few decades mostly due to the concomitant rise in hepatitis viral infection and the occurrence of obesity especially in the United States. Unlike most other cancers, liver cancer is really two diseases in one; since the cancer cells generally form in the context of a diseased liver, called cirrhotic, itself caused by chronic inflammation due to a toxic insult (hepatitis B or C, obesity or chronic alcohol ingestion).

Identifying the early signs of liver cancer can be difficult as symptoms do not typically become apparent until later stages, which explains why most patients are diagnosed at later stages making curative intervention difficult. To make matters worse, when symptoms are present, they are generally non-specific, making them difficult to relate to liver cancer as the primary cause. Some common symptoms include:

• A hard lump or discomfort in the right side of your abdomen, below the rib cage
• Jaundice – when the skin or whites of the eyes develop a yellow tint
• Loss of appetite and weight loss without reason
• Extreme tiredness or weakness
• Pale bowel movements or dark urine

While experiencing any one of these symptoms does not automatically mean that a person has primary liver cancer, they can still be the result of a number of medical issues. Any sudden change to your normal state of health should always prompt a consultation with a doctor. A physical examination and blood work, especially laboratory testing of the function of the liver through a simple blood test should provide evidence confirming or ruling out the diagnosis of liver cancer. Such tests include:

• Physical examination – This is performed by the doctor examining carefully the abdomen, and the body as a whole, looking for subtle signs indicating the presence of liver cancer. A thorough medical history is also obtained at that time.
• CT scan or MRI – Both scans take multiple pictures of the body at different angles. A dye is often injected through a vein in the forearm to help identify subtle areas of abnormalities in the body, especially the liver. Primary liver tumors demonstrate characteristic imaging features that could also help establish a definitive diagnosis.
• Serum tumor markers – Tumors can secrete abnormal proteins that can be identified in a blood sample. Such proteins are known as tumor markers and when present can help identify the tumor type. In the case of primary liver cancer, a higher than normal amount of alpha-fetoprotein (AFP) in the blood is generally diagnostic of liver cancer. Unfortunately, such abnormal levels are only present in about half of all cases, but when present is virtually pathognomonic of liver cancer.
• Biopsy – Sometimes it is necessary to obtain some tissue within the region of interest to make sure that what is being seen on a CT or MRI scan is indeed a malignant tumor. If the blood test (above) is unhelpful, then sometimes a tissue biopsy will be required to confirm the diagnosis of liver cancer. The analysis of the tissue can also help guide therapy by selecting the most appropriate drugs available.

The prognosis of adult primary liver cancer is generally poor. This is due to the fact that most patients present with advanced stage making it extremely difficult to treat them effectively. On the other hand, if the cancer is diagnosed early, a number of therapeutic options may be available to the patients, including liver transplantation by far the most likely to “cure” the patient since it not only removes the cancer but also the underlying diseased liver. Ultimately, treatment decisions are made by a team of specialists in liver cancer based on treatment guidelines, stage of the disease and status of the patient’s general health. Commonly used treatments include:

• Surgery to remove the tumor or part of the liver
• Liver transplant that replaces the entire liver organ with a new one
• Chemotherapy or radiation to reduce the size of the tumor and stop the cancer cells from developing
• Targeted therapy
• Embolization therapy that exploits the unique blood supply of the liver to precisely kill tumors inside the liver

Despite significant improvements in the management of primary liver cancer, it remains a major health issue especially given the epidemic rise in its incidence worldwide and in the US. It is one of the most highly lethal cancers worldwide (top 3) mostly due to the fact it is diagnosed late. As a result, median life expectancy once diagnosed with primary liver cancer remains in 9 months range. The advent of new drug therapies and improvement in localized targeted treatments, the survival of those able to be treated has increased significantly. This is a small progress but progress nonetheless.