Liver cancer
Liver cancer, also known as hepatic cancer and primary hepatic cancer, is cancer that starts in the liver. Cancer which has spread from elsewhere to the liver, known as liver metastasis, is more common than that which starts in the liver. Symptoms of liver cancer may include a lump or pain in the right side below the rib cage, swelling of the abdomen, yellowish skin, easy bruising, weight loss, and weakness.
The leading cause of liver cancer is cirrhosis due to hepatitis B, hepatitis C, or alcohol. Other causes include aflatoxin, non-alcoholic fatty liver disease, and liver flukes. The most common types are hepatocellular carcinoma (HCC), which makes up 80% of cases, and cholangiocarcinoma. Less common types include mucinous cystic neoplasm and intraductal papillary biliary neoplasm. The diagnosis may be supported by blood tests and medical imaging with confirmation by tissue biopsy.
Preventive 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 certain cases ablation therapy, embolization therapy, or liver transplantation may be used. Small lumps in the liver may be closely followed.
Primary liver cancer is globally the sixth most frequent cancer (6%) and the second leading cause of death from cancer (9%). In 2012 it occurred in 782,000 people and in 2015 resulted in 810,500 deaths. In 2015, 263,000 deaths from liver cancer were due to hepatitis B, 167,000 to hepatitis C, and 245,000 to alcohol. Higher rates of liver cancer occur where hepatitis B and C are common, including Asia and sub-Saharan Africa. Males are more often affected with HCC than females. Diagnosis is most frequent among those 55 to 65 years old. Five-year survival rates are 18% in the United States. The word "hepatic" is from the Greek "hêpar", meaning "liver".
Liver support systems
In hyperacute and acute liver failure the clinical picture develops rapidly with progressive encephalopathy and multiorgan dysfunction such as hyperdynamic circulation, coagulopathy, acute renal and respiratory insufficiency, severe metabolic alterations and cerebral edema that can lead to brain death. In these cases the mortality without liver transplantation (LTx) ranges between 40-80%. LTx is the only effective treatment for these patients although it requires a precise indication and timing to achieve good results. Nevertheless, due to the scarcity of organs to carry out liver transplantations, it is estimated that one third of patients with ALF die while waiting to be transplanted.
On the other hand, a patient with a chronic hepatic disease can suffer an acute decompensation of liver function following a precipitating event such as variceal bleeding, sepsis and excessive alcohol intake among others that can lead to a condition referred to as acute-on-chronic liver failure (ACLF).
Both types of hepatic insufficiency, ALF and ACLF, can potentially be reversible and liver functionality can return to a level similar to that prior to the insult or precipitating event.
LTx is the only treatment that has shown an improvement in the prognosis and survival with most severe cases of ALF. Nevertheless, cost and donor scarcity have prompted researchers to look for new supportive treatments that can act as “bridge” to the transplant procedure. By stabilizing the patient’s clinical state, or by creating the right conditions that could allow the recovery of native liver functions, both detoxification and synthesis can improve, after an episode of ALF or ACLF.
Basically, three different types of supportive therapies have been developed: bio-artificial, artificial and hybrid liver support systems (Table 2).