Liver Cancer is a form of cancer that begins in the cells of your liver. Your liver is a football-sized organ that sits in the upper right portion of your abdomen, beneath your diaphragm and above your stomach.
Liver cancer is one of the most common forms of cancer in the world, but liver cancer is uncommon in the United States. Rates of liver cancer diagnosis are increasing in the United States.
Not all cancers that affect the liver are considered liver cancer. Cancer that begins in another area of the body, such as the colon, lung or breast, and then spreads to the liver is called metastatic cancer, rather than liver cancer. And this type of cancer is named after the organ in which it began — such as metastatic colon cancer to describe cancer that begins in the colon and spreads to the liver.
Most people don't have signs and symptoms in the early stages of primary liver cancer. When signs and symptoms do appear, they may include:
Losing weight without trying
Loss of appetite
Upper abdominal pain
Nausea and vomiting
General weakness and fatigue
An enlarged liver
Yellow discoloration of your skin and the whites of your eyes (jaundice)
White, chalky stools
It's not clear what causes most cases of liver cancer. But in some cases, the cause is known. For instance, chronic infection with certain hepatitis viruses can cause liver cancer.
Liver cancer occurs when liver cells develop changes (mutations) in their DNA — the material that provides instructions for every chemical process in your body. DNA mutations cause changes in these instructions. One result is that cells may begin to grow out of control and eventually form a tumor — a mass of cancerous cells.
Types of liver cancer
Primary liver cancer, which begins in the cells of the liver, is divided into different types based on the kind of cells that become cancerous. Types include:
Hepatocellular carcinoma. This is the most common form of primary liver cancer. It starts in the hepatocytes, the main type of liver cell.
Cholangiocarcinoma. This type of cancer begins in the small tube-like bile ducts within the liver. This type of cancer is sometimes called bile duct cancer.
Hepatoblastoma. This liver cancer affects infants and young children.
Angiosarcoma or hemangiosarcoma. These cancers begin in the blood vessels of the liver and grow very quickly.
Factors that increase the risk of primary liver cancer include:
Your sex. Men are more likely to develop liver cancer than are women.
Your age. In North America, Europe and Australia, liver cancer most commonly affects older adults. In developing countries of Asia and Africa, liver cancer diagnosis tends to occur at a younger age — between 20 and 50.
Chronic infection with HBV or HCV. Chronic infection with hepatitis B virus (HBV) or hepatitis C virus (HCV) increases your risk of liver cancer.
Cirrhosis. This progressive and irreversible condition causes scar tissue to form in your liver and increases your chances of developing liver cancer.
Certain inherited liver diseases. Liver diseases that can increase the risk of liver cancer include hemochromatosis and Wilson's disease.
Diabetes. People with this blood sugar disorder have a greater risk of liver cancer than do people who don't have diabetes.
Nonalcoholic fatty liver disease. An accumulation of fat in the liver increases the risk of liver cancer.
Exposure to aflatoxins. Consuming foods contaminated with fungi that produce aflatoxins greatly increases the risk of liver cancer. Crops such as corn and peanuts can become contaminated with aflatoxins. In the United States, safety regulations limit aflatoxin contamination. Aflatoxin contamination is more common in certain parts of Africa and Asia.
Excessive alcohol consumption. Consuming more than a moderate amount of alcohol daily over many years can lead to irreversible liver damage and increase your risk of liver cancer.
Obesity. Having an unhealthy body mass index increases the risk of liver cancer.
Cancer is a class of diseases characterized by out-of-control cell growth. There are over 100 different types of cancer, and each is classified by the type of cell that is initially affected.
Cancer harms the body when damaged cells divide uncontrollably to form lumps or masses of tissue called tumors (except in the case of leukemia where cancer prohibits normal blood function by abnormal cell division in the blood stream). Tumors can grow and interfere with the digestive, nervous, and circulatory systems, and they can release hormones that alter body function. Tumors that stay in one spot and demonstrate limited growth are generally considered to be benign.
More dangerous, or malignant, tumors form when two things occur:
A cancerous cell manages to move throughout the body using the blood or lymph systems, destroying healthy tissue in a process called invasion
That cell manages to divide and grow, making new blood vessels to feed itself in a process called angiogenesis.
When a tumor successfully spreads to other parts of the body and grows, invading and destroying other healthy tissues, it is said to have metastasized. This process itself is called metastasis, and the result is a serious condition that is very difficult to treat.
Cancer is ultimately the result of cells that uncontrollably grow and do not die. Normal cells in the body follow an orderly path of growth, division, and death. Programmed cell death is called apoptosis, and when this process breaks down, cancer begins to form. Unlike regular cells, cancer cells do not experience programmatic death and instead continue to grow and divide. This leads to a mass of abnormal cells that grows out of control.
Cancer symptoms are quite varied and depend on where the cancer is located, where it has spread, and how big the tumor is. Some cancers can be felt or seen through the skin - a lump on the breast or testicle can be an indicator of cancer in those locations. Skin cancer (melanoma) is often noted by a change in a wart or mole on the skin. Some oral cancers present white patches inside the mouth or white spots on the tongue.
Other cancers have symptoms that are less physically apparent. Some brain tumors tend to present symptoms early in the disease as they affect important cognitive functions. Pancreas cancers are usually too small to cause symptoms until they cause pain by pushing against nearby nerves or interfere with liver function to cause a yellowing of the skin and eyes called jaundice. Symptoms also can be created as a tumor grows and pushes against organs and blood vessels. For example, colon cancers lead to symptoms such as constipation, diarrhea, and changes in stool size. Bladder or prostate cancers cause changes in bladder function such as more frequent or infrequent urination.
As cancer cells use the body's energy and interfere with normal hormone function, it is possible to present symptoms such as fever, fatigue, excessive sweating, anemia, and unexplained weight loss. However, these symptoms are common in several other maladies as well. For example, coughing and hoarseness can point to lung or throat cancer as well as several other conditions.
When cancer spreads, or metastasizes, additional symptoms can present themselves in the newly affected area. Swollen or enlarged lymph nodes are common and likely to be present early. If cancer spreads to the brain, patients may experience vertigo, headaches, or seizures. Spreading to the lungs may cause coughing and shortness of breath. In addition, the liver may become enlarged and cause jaundice and bones can become painful, brittle, and break easily. Symptoms of metastasis ultimately depend on the location to which the cancer has spread.
There are five broad groups that are used to classify cancer.
Carcinomas are characterized by cells that cover internal and external parts of the body such as lung, breast, and colon cancer.
Sarcomas are characterized by cells that are located in bone, cartilage, fat, connective tissue, muscle, and other supportive tissues.
Lymphomas are cancers that begin in the lymph nodes and immune system tissues.
Leukemias are cancers that begin in the bone marrow and often accumulate in the bloodstream.
Adenomas are cancers that arise in the thyroid, the pituitary gland, the adrenal gland, and other glandular tissues.
Cancers are often referred to by terms that contain a prefix related to the cell type in which the cancer originated and a suffix such as -sarcoma, -carcinoma, or just -oma. Common prefixes include:
Adeno- = gland
Chondro- = cartilage
Erythro- = red blood cell
Hemangio- = blood vessels
Hepato- = liver
Lipo- = fat
Lympho- = white blood cell
Melano- = pigment cell
Myelo- = bone marrow
Myo- = muscle
Osteo- = bone
Uro- = bladder
Retino- = eye
Neuro- = brain
Early detection of cancer can greatly improve the odds of successful treatment and survival. Physicians use information from symptoms and several other procedures to diagnose cancer. Imaging techniques such as X-rays, CT scans, MRI scans, PET scans, and ultrasound scans are used regularly in order to detect where a tumor is located and what organs may be affected by it. Doctors may also conduct an endoscopy, which is a procedure that uses a thin tube with a camera and light at one end, to look for abnormalities inside the body.
Extracting cancer cells and looking at them under a microscope is the only absolute way to diagnose cancer. This procedure is called a biopsy. Other types of molecular diagnostic tests are frequently employed as well. Physicians will analyze your body's sugars, fats, proteins, and DNA at the molecular level. For example, cancerous prostate cells release a higher level of a chemical called PSA (prostate-specific antigen) into the bloodstream that can be detected by a blood test. Molecular diagnostics, biopsies, and imaging techniques are all used together to diagnose cancer.