Liver cancer , also known as liver cancer and primary liver cancer , is a cancer that begins in the liver. Cancers that have spread from elsewhere to the liver, known as liver metastases, are more common than those that begin in the liver. Symptoms of liver cancer may include a lump or pain in the lower right side of the ribs, abdominal swelling, yellowish skin, easy bruising, weight loss, and weakness.
The main cause of liver cancer is cirrhosis due to hepatitis B, hepatitis C, or alcohol. Other causes include aflatoxin, non-alcoholic fatty liver disease, and hepatic worms. The most common type is hepatocellular carcinoma (HCC), which accounts for 80% of cases, and cholangiocarcinoma. Less common types include mucinous cystic neoplasms and intraductal papillary biliary neoplasms. Diagnosis may be supported by blood tests and medical imaging with confirmation by tissue biopsy.
Prevention efforts include immunization against hepatitis B and treating those infected with hepatitis B or C. Screening is recommended in those with chronic liver disease. Treatment options may include surgery, targeted therapy, and radiation therapy. In some cases, ablation therapy, embolization therapy, or liver transplantation may be used. Small lumps in the liver may be closely followed.
Primary liver cancer globally is the sixth most frequent cancer (6%) and the second leading cause of cancer death (9%). In 2012 it happens to 782,000 people and in 2015 resulted in 810,500 deaths. By 2015, 263,000 deaths from liver cancer are caused by hepatitis B, 167,000 for hepatitis C, and 245,000 alcohol. Higher rates of liver cancer occur where hepatitis B and C are common, including Asian and sub-Saharan Africa. Men are more commonly affected by HCC than women. Diagnosis most commonly occurs in those aged 55 to 65 years. The five-year survival rate is 18% in the United States. The word "hepatic" comes from the Greek hÃÆ'ªpar , meaning "heart."
Video Liver cancer
Classification
The most common liver cancer, accounting for about 75% of all primary liver cancers, is hepatocellular carcinoma (also called hepatoma , which is a misnomer because adenomas are usually benign). HCC is a cancer formed by liver cells, known as hepatocytes, which become malignant. Another type of cancer that is formed by liver cells is hepatoblastoma, which is specifically formed by immature liver cells. It is a rare malignant tumor that mainly develops in children, and accounts for about 1% of all cancers in children and 79% of all primary liver cancers are under the age of 15. Most forms of hepatoblastoma in the right lobe.
Liver cancer can also be formed from other structures in the liver such as bile ducts, blood vessels and immune cells. Cancer of the bile duct (cholangiocarcinoma and cholystocellular cystadenocarcinoma) accounts for about 6% of primary liver cancers. There is also a type of HCC variant consisting of HCC and cholangiocarcinoma. Blood vessel tumors (angiosarcoma and hemangioendothelioma, embrional sarcoma and fibrosarcoma are produced from a type of connective tissue known as mesenchyme.Liver cancer resulting from muscle in the liver are leiomyosarcoma and rhabdomyosarcoma.Another unusual liver cancers include carcinosarcomas, teratoma, yolk sac Tumors, tumors carcinoid and lymphoma, lymphomas usually have diffuse infiltration to the liver, but also can form liver mass in some rare occasions.
Many cancers found in the liver are not true liver cancer, but cancer from other sites in the body that have spread to the liver (known as metastasis). Often, the place of origin is the digestive tract, because the liver is close to many of the metabolically active and blood-rich organs near the blood vessels and lymph nodes (such as pancreatic cancer, stomach cancer, colon cancer and carcinoid tumors mainly from appendicitis) but also from breast cancer, ovarian cancer, lung cancer, kidney cancer, prostate cancer.
Maps Liver cancer
Signs and symptoms
Because liver cancer is a common term for many types of cancer, the signs and symptoms depend on what type of cancer there is. Cholangiocarcinoma is associated with sweating, jaundice, abdominal pain, weight loss and liver enlargement. Hepatocellular carcinoma is associated with abdominal mass, abdominal pain, vomiting, anemia, back pain, jaundice, itching, weight loss and fever.
Cause
Virus infection
Viral infection with hepatitis C virus (HCV) or hepatitis B virus (HBV) is the leading cause of liver cancer in the world today, accounting for 80% of hepatocellular cancer (HCC). The virus causes HCC because of major inflammation, fibrosis and eventually cirrhosis occurs in the liver. HCC usually appears after cirrhosis, with an annual incidence of 1.7% in HCV-infected individuals cirrhosis. About 5-10% of individuals who become infected with HBV become chronic carriers, and about 30% of them get chronic liver disease, which can cause HCC. HBV infection is also associated with cholangiocarcinoma. The role of viruses other than HCV or HBV in liver cancer is less clear, although there is some evidence that HBV coinfection and hepatitis D virus may increase the risk of liver cancer.
Many genetic and epigenetic changes are formed in liver cells during HCV and HBV infection, which is a major factor in the production of liver tumors. The virus induces malignant changes in cells by altering gene methylation, affecting gene expression and promoting or suppressing cellular signal transduction pathways. By doing this, the virus can prevent cells from undergoing a form of cell death (apoptosis) program and promote viral replication and persistence.
HBV and HCV also induce malignant changes by causing DNA damage and genomic instability. This is by creating reactive oxygen species, expressing proteins that interfere with DNA repair enzymes, and HCV causes mutator enzyme activation.
Cirrhosis
In addition to the virus-related cirrhosis described above, other causes of cirrhosis can cause HCC. Alcohol intake is correlated with the risk of HCC, and the risk is much greater in individuals with alcohol-induced cirrhosis. There are several disorders known to cause cirrhosis and cause cancer, including hereditary hemochromatosis and primary biliary cirrhosis.
Aflatoxin
Exposure to aflatoxin may cause HCC development. Aflatoxins are a group of chemicals produced by the fungus Aspergillus flavus (names derived from A. Flavus toxin) and A. parasiticus . Contamination of food by the fungus leads to the consumption of chemicals, which are very toxic to the liver. Common foods contaminated with toxins are cereals, peanuts and other vegetables. Food contamination is common in Africa, Southeast Asia and China. Concurrent HBV infection and aflatoxin exposure increase the risk of liver cancer by more than threefold seen in HBV-infected individuals without exposure to aflatoxin. The mechanism by which aflatoxin causes cancer is through genetic mutations of genes necessary for cancer prevention: p53.
Other causes of adult
- High-grade dysplastic nodules are precancerous liver lesions. Within 2 years, there is a cancer risk arising from this nodule 30-40%.
- Obesity has emerged as an important risk factor because it can cause steatohepatitis.
- Diabetes increases the risk of HCC.
- Smoking increases the risk of HCC compared with non-smokers and previous smokers.
- There is a 5-10% lifetime risk of cholangiocarcinoma in people with primary sclerosing cholangitis.
- Liverworm infection increases the risk of cholangiocarcinoma, and is the reason Thailand has a very high cancer rate.
Children
Increased risk of liver cancer in children can be caused by Beckwith-Wiedemann Syndrome (associated with hepatoblastoma), familial adenomatous polyposis (associated with hepatoblastoma), low birth weight (associated with hepatoblastoma), progressive familial intrahepatic cholestasis (associated with HCC) and Trisomy 18 (associated with hepatoblastoma).
Diagnosis
Many imaging modalities are used to help diagnose primary liver cancer. For HCC it includes sonography (ultrasound), computed tomography (CT) and magnetic resonance imaging (MRI). When imaging the liver with ultrasound, a mass greater than 2 cm has a likelihood of more than 95% to HCC. The majority of cholangiocarcimas occur in the hilum area of ​​the liver, and often appear as obstruction of the bile ducts. If the cause of obstruction is suspected to be malignant, retrograde endoscopic cholangiopancreatography (ERCP), ultrasound, CT, MRI and magnetic resonance cholangiopancreatography (MRCP) are used.
The tumor marker, a chemical sometimes found in the blood of cancer patients, can help in diagnosing and monitoring the course of liver cancer. High levels of alpha-fetoprotein (AFP) in the blood can be found in many cases of HCC and intrahepatic cholangiocarcinoma. Cholangiocarcinoma can be detected with commonly used tumor markers: carb antibody 19-9 (CA 19-9), carbinoembryonic antigen (CEA) and cancer antigen 125 (CA125). These tumor markers are found in primary liver cancer, as well as in other cancers and certain other disorders.
Prevention
Cancer prevention can be separated into primary, secondary, and tertiary prevention. Primary prevention first reduces exposure to risk factors for liver cancer. One of the most successful primary liver cancer prevention is vaccination against hepatitis B. Vaccination against hepatitis C virus is currently unavailable. Other primary forms of prevention are aimed at limiting the transmission of these viruses by promoting safe injection practices, filtering out blood donor products, and screening at-risk individuals asymptomatic. Exposure to aflatoxin can be avoided by post-harvest intervention to prevent fungus, which has been effective in western Africa. Reducing alcohol abuse, obesity, and diabetes will also reduce the rate of liver cancer. Dietary control in hemochromatosis may decrease the risk of excess iron, lowering the risk of cancer.
Secondary prevention includes both curing agents involved in cancer formation (carcinogenesis) and prevention of carcinogenesis if this is not possible. Curing individuals infected with the virus is not possible, but treatment with antiviral drugs such as interferon may decrease the risk of liver cancer. Chlorophyllin may have potential in reducing the effects of aflatoxin.
Tertiary prevention includes treatments to prevent the recurrence of liver cancer. This includes the use of chemotherapy drugs and antiviral drugs.
Treatment
Hepatocellular carcinoma
Partial surgical resection is the optimal treatment for hepatocellular carcinoma (HCC) when the patient has adequate liver function reserves. Increased risk of complications such as liver failure can occur with cirrhotic resection (ie less than functional) liver function. The 5-year survival rate after resection has increased massively over the last few decades and now can exceed 50%. However, the recurrence rate after resection may exceed 70%, whether due to early tumor spread or new tumor formation. Liver transplantation can also be considered in cases of HCC where this form of treatment is tolerable and tumors meet certain criteria (such as the Milan criteria). In general, patients considered for liver transplantation have multiple hepatic lesions, underlying hepatic dysfunction, or both. Less than 30-40% of individuals with HCC are eligible for surgery and transplantation because cancer is often detected in the late stages. Also, HCC may develop during waiting times for liver transplants, which can prevent transplants due to strict criteria.
Percutaneous ablation is the only non-surgical treatment that can offer healing. There are many forms of percutaneous ablation, which consists of injecting chemicals into the liver (ethanol or acetic acid) or producing extreme temperatures using radio frequency ablation, microwaves, lasers or cryotherapy. Of these, radio frequency ablation has one of the best reputations in HCC, but its limitations include the inability to treat tumors close to other organs and blood vessels due to the formation of heat and heat sink effects, respectively. In addition, the long-term outcomes of percutaneous ablation procedures for liver cancer have not been well studied. In general, surgery is the preferred treatment modality whenever possible.
Systemic chemotherapy is not routinely used in HCC, although local chemotherapy can be used in a procedure known as transarterial chemoembolization. In this procedure, cytotoxic drugs such as doxorubicin or cisplatin with lipiodol are administered and the arteries supplying the liver are blocked by gelatin sponges or other particles. Since most systemic drugs have no efficacy in the treatment of HCC, research into the molecular pathway involved in the production of liver cancer produces sorafenib, a targeted therapeutic drug that prevents cell proliferation and blood cell growth. Sorafenib obtained FDA approval for the treatment of advanced hepatocellular carcinoma in November 2007. This drug provides survival benefits for advanced liver cancer.
Radiotherapy is not often used in HCC because the liver is intolerant of radiation. Although with modern technology it is possible to deliver well-targeted radiation to the tumor, minimizing the dose to the rest of the liver. Multiple radiotherapy treatments plus chemoembolization, local chemotherapy, systemic chemotherapy or targeted therapeutic drugs may show benefits rather than radiotherapy alone.
Cholangiocarcinoma
Resection is an option in cholangiocarcinoma, but fewer than 30% of cases of cholangiocarcinoma can be operated upon diagnosis. After surgery, the recurrence rate is up to 60%. Liver transplantation may be used if partial resection is not an option, and adjuvant chemoradiation may be beneficial in some cases.
60% of cholangiocarcinomas are formed in perihilar areas and photodynamic therapy can be used to improve quality of life and survival time in cases that are inoperable. Photodynamic therapy is a new treatment that utilizes light-activated molecules to treat tumors. This compound is activated in the tumor region by a laser beam, which causes the release of reactive oxygen species toxic, killing tumor cells.
Systemic chemotherapies such as gemcitabine and cisplatin are sometimes used in cases of inoperable cholangiocarcinoma.
Radio frequency ablation, transarterial chemoembolization and internal radiotherapy (brachytherapy) all promise in the treatment of cholangiocarcinoma.
Radiotherapy may be used in adjuvant settings or for the treatment of cholangiocarcinoma palliative.
Hepatoblastoma
Removing a tumor with surgical resection or liver transplantation can be used in the treatment of hepatoblastoma. In some cases, surgery can offer healing. Chemotherapy can be used before and after surgery and transplantation.
Chemotherapy, including cisplatin, vincristine, cyclophosphamide, and doxorubicin are used for the treatment of systemic hepatoblastoma. Of these drugs, cisplatin seems most effective.
Epidemiology
Globally, in 2010, liver cancer produced 754,000 deaths, up from 460,000 in 1990, making it the third leading cause of cancer deaths after lung and stomach. In 2012, it represents a 7% cancer diagnosis in men, the 5th most diagnosed cancer of that year. Of these 340,000 deaths are secondary to hepatitis B, 196,000 are secondary to hepatitis C, and 150,000 are secondary to alcohol. HCC, the most common form of liver cancer, shows a striking geographical distribution. China has 50% of HCC cases globally, and more than 80% of total cases occur in sub-Saharan Africa or in East Asia due to hepatitis B virus. Cholangiocarcinoma also has a significant geographical distribution, with Thailand showing the highest rates worldwide due to presence heartworm.
English
Liver cancer is the eighteenth most common cancer in the UK (about 4,300 people diagnosed with liver cancer in the UK in 2011), and that is the cause of twelve cancer deaths (about 4,500 people die from illness in 2012).
India
The number of new cases of hepatocellular carcinoma per year in India in men is about 4.1 and for women 1.2 per 100,000. Usually occurs between 40 and 70 years.
Research
Hepcortespenlisimut-L is an oral immunotherapy that will pass a phase 3 clinical trial for HCC.
See also
- Timeline of liver cancer
References
External links
- Liver Cancer at Johns Hopkins University
- Liver cancer at Mayo Clinic
- Liver cancer information from Cancer Research UK
Source of the article : Wikipedia
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