Definition of Liver Cancer :
Liver cancer or hepatic cancer is a cancer that originates in the liver. Liver cancers are malignant tumors that grow on the surface or inside the liver. Liver tumors are discovered on medical imaging equipment (often by accident) or present themselves symptomatically as an abdominal mass, abdominal pain, jaundice, nausea or liver dysfunction. Liver cancers should not be confused with liver metastases, which are cancers that originate from organs elsewhere in the body and migrate to the liver.
There are many forms of liver cancer, although many cancers found in the liver are metastases from other tumors, frequently of the GI tract (like colon cancer, carcinoid tumors mainly of theappendix, etc.), but also from breast cancer, ovarian cancer, lung cancer, renal cancer, prostate cancer, etc.
The most frequent liver cancer is hepatocellular carcinoma (HCC) (also named hepatoma, which is a misnomer because adenomas are usually benign). This tumor also has a variant type that consists of both HCC and cholangiocarcinoma components. The cells of the bile duct coexist next to the bile ducts that drain the bile produced by the hepatocytes of the liver. Cancers that arise from the blood vessel cells in the liver are known as hemangioendotheliomas.
As well as mixed tumors, rarer forms of liver cancer include:
- mesenchymal tissue
- Hepatoblastoma, a rare malignant tumor, primarily developing in children. Most of these tumors form in the right lobe.
- Cholangiocarcinoma (bile duct cancers), which account for 1 or 2 out of every 10 cases of liver cancer. These cancers start in the small tubes (called bile ducts) that carry bile to the intestine.
- Angiosarcoma and hemangiosarcoma: These are rare forms of cancer that start in the blood vessels of the liver. These tumors grow quickly. Often by the time they are found they are too widespread to be removed. Most patients do not live more than a year after diagnosis.
- Lymphoma of liver: A rare form of lymphoma that usually have diffuse infiltration to liver. It may also form a liver mass in rare occasions.
Cause of Liver Cancer :
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.
Ababolic steroids - used by athletes and weight lifters. These male hormones, if used regularly and for long enough can raise the risk of developing liver cancer, as well as some other cancers.
Livers damaged by birth defects, alcohol abuse, or chronic infection with diseases such as hepatitis B and C, hemochromatosis (a hereditary disease associated with too much iron in the liver), and cirrhosis.
Aflatoxins - Aflatoxins, cancer-causing substances made by a type of plant mold, have also been implicated. Aflatoxins can contaminate wheat, peanuts, rice, corn, and soybeans. These are rare problems in most developed countries like the U.S.
Cirrhosis - when liver cells are damaged and replaced with scar tissue. People with cirrhosis of the liver have a higher risk of developing liver cancer.
Family history - people whose mother, father, brother, or sister with liver cancer have a higher risk of developing it themselves, compared to others.
L-carnitine deficiency - studies suggest that an l-carnitine deficiency increases the risk of developing liver cancer.
Liver disease and inherited liver disease - people with hepatitis B or C have a significantly higher risk of developing liver cancer, compared to other healthy individuals. According to the American Cancer Society, hepatitis C is the most common cause of liver cancer in the USA. The Society mentions that some inherited liver diseases also increase the risk of liver cancer.
Low immunity - people with weakened immune systems, such as those with HIV/AIDS have a risk of liver cancer that is five times greater than other healthy individuals.
Smoking -Smoking, especially if you abuse alcohol as well, also increases risk.
Water wells with arsenic - Various cancer-causing substances are associated with primary liver cancer, including certain herbicides and chemicals such as vinyl chloride and arsenic.
Signs and Symptoms of Liver Cancer :
- Abdominal pain
- Weight loss
Risk Factors for Liver Cancer :
Risk factors for adults developing primary liver cancer:
- Hepatitis C is the primary cause of liver cancer.
- Chronic Hepatitis B infection
- Aflatoxin exposure
- Obesity has emerged as an important risk factor as it can lead to steatohepatitis
Risk factors for children developing primary liver cancer:
- Alagille syndrome (associated with HCC)
- Beckwith-Wiedemann Syndrome (associated with hepatoblastoma)
- Familial adenomatous polyposis (associated with hepatoblastoma)
- Glycogen storage diseases (associated with both HCC and hepatoblastoma)
- Hepatitis B infection, associated when contracted in the perinatal period (with transmission at birth) (associated with HCC)
- Low birth weight (associated with hepatoblastoma)
- Progressive familial intrahepatic cholestasis (associated with HCC)
- Trisomy 18, as well as other trisomies (associated with hepatoblastoma)
- Tyrosinemia (associated with HCC)
Diagnosis of Liver Cancer :
Tests and procedures used to diagnose liver cancer include:
- Blood tests. afp (alpha fetoprotein), a type of protein, is produced by liver tumors and can be detected in a blood test.
- Imaging tests. either an MRI or CT scan
- Removing a sample of liver tissue for testing. a small sample of tumor tissue is removed and analyzed. The analysis can reveal whether the tumor is cancerous (malignant) or non-cancerous (benign).
Determining the extent of the liver cancer
Once liver cancer is diagnosed, your doctor will work to determine the extent (stage) of the cancer.
- Stage 1 - the tumor is just in/on the liver and nowhere else.
- Stage 2 - either there are several small tumors, but all within the liver, or one tumor that has reached a blood vessel.
- Stage 3 - either there are various large tumors, or there is just one that has reached the main blood vessel(s). Cancer may have also reached the gallbladder.
- Stage 4 - metastasis. The liver cancer has spread to other parts of the body.
Staging tests help determine the size and location of cancer and whether it has spread. Imaging tests used to stage liver cancer include CT, MRI, chest X-ray and bone scan.
Prevention from Liver Cancer :
Since hepatitis B or C is one of the main causes of liver cancer, childhood vaccination against hepatitis B may reduce the risk of liver cancer in the future. In the case of patients with cirrhosis, alcohol consumption is to be avoided.
Treatment of Liver Cancer :
A PET-CT scan may be suggested if doctors are considering surgery as a treatment. It gives more detailed information about the part of the body being scanned. The correct treatment of liver cancer can mean the difference between life and death. Not all patients with cancers in the liver are potentially curable. These are some of the treatments available: Surgery, Chemotherapy,Immunotherapy, Photodynamic Therapy, Hyperthermia, Radiation Therapy and Radiosurgery.
- Partial hepatectomy to resect all of the tumor.
- Liver transplantation
- Radiofrequency ablation
- Radiofrequency ablation combined with local chemotherapy
- Photodynamic therapy
- Liver transplantation