Rabu, 27 Agustus 2008

Liver Cancer

What is liver cancer (hepatocellular carcinoma, HCC)?

Liver cancer (hepatocellular carcinoma) is a cancer arising from the liver. It is also known as primary liver cancer or hepatoma. The liver is made up of different cell types (for example, bile ducts, blood vessels, and fat-storing cells). However, liver cells (hepatocytes) make up 80% of the liver tissue. Thus, the majority of primary liver cancers (over 90 to 95%) arises from liver cells and is called hepatocellular cancer or carcinoma.

When patients or physicians speak of liver cancer, however, they are often referring to cancer that has spread to the liver, having originated in other organs (such as the colon, stomach, pancreas, breast, and lung). More specifically, this type of liver cancer is called metastatic liver disease (cancer) or secondary liver cancer. Thus, the term liver cancer actually can refer to either metastatic liver cancer or hepatocellular cancer. The subject of this article is hepatocellular carcinoma, which I will refer to as liver cancer.

What is the scope of the liver cancer problem?

Liver cancer is the fifth most common cancer in the world. A deadly cancer, liver cancer will kill almost all patients who have it within a year. In 1990, the World Health Organization estimated that there were about 430,000 new cases of liver cancer worldwide, and a similar number of patients died as a result of this disease. About three quarters of the cases of liver cancer are found in Southeast Asia (China, Hong Kong, Taiwan, Korea, and Japan). Liver cancer is also very common in sub-Saharan Africa (Mozambique and South Africa).

The frequency of liver cancer in Southeast Asia and sub-Saharan Africa is greater than 20 cases per 100,000 population. In contrast, the frequency of liver cancer in North America and Western Europe is much lower, less than five per 100,000 population. However, the frequency of liver cancer among native Alaskans is comparable to that seen in Southeast Asia. Moreover, recent data show that the frequency of liver cancer in the U.S. overall is rising. This increase is due primarily to chronic hepatitis C, an infection of the liver that causes liver cancer.

What are the population characteristics (epidemiology) of liver cancer?

In the U.S. the highest frequency of liver cancer occurs in immigrants from Asian countries, where liver cancer is common. The frequency of liver cancer among Caucasians is the lowest, whereas among African-Americans and Hispanics, it is intermediate. The frequency of liver cancer is high among Asians because liver cancer is closely linked to chronic hepatitis B infection. This is especially so in individuals who have been infected with chronic hepatitis B for most of their lives. If you take a world map depicting the frequency of chronic hepatitis B infection, you can easily superimpose that map on a map showing the frequency of liver cancer.

The initial presentation (symptoms) of liver cancer in patients in areas of high liver cancer frequency is quite different from that seen in low frequency areas. Patients from high frequency areas usually start developing liver cancer in their 40s, and the cancer is usually more aggressive. That is, the liver cancer presents with severe symptoms and is inoperable (too advanced for surgery) at the time of diagnosis. Also, in these areas, the frequency of liver cancer is three to four times higher in men than in women, and most of these patients are infected with chronic hepatitis B. In contrast, liver cancer in lower risk areas occurs in patients in their 50s and 60s and the predominance of men is less striking.

What are the risk factors for liver cancer?

Hepatitis B infection

The role of hepatitis B virus (HBV) infection in causing liver cancer is well established. Several lines of evidence point to this strong association. As noted earlier, the frequency of liver cancer relates to (correlates with) the frequency of chronic hepatitis B virus infection. In addition, the patients with hepatitis B virus who are at greatest risk for liver cancer are men with hepatitis B virus cirrhosis (scarring of the liver) and a family history of liver cancer. Perhaps the most convincing evidence, however, comes from a prospective (looking forward in time) study done in the 1970's in Taiwan involving male government employees over the age of 40. In this study, the investigators found that the risk of developing liver cancer was 200 times higher among employees who had chronic hepatitis B virus as compared to employees without chronic hepatitis B virus!

Studies in animals also have provided evidence that hepatitis B virus can cause liver cancer. For example, we have learned that liver cancer develops in other mammals that are naturally infected with hepatitis B virus-related viruses. Finally, by infecting transgenic mice with certain parts of the hepatitis B virus, scientists caused liver cancer to develop in mice that do not usually develop liver cancer. (Transgenic mice are mice that have been injected with new or foreign genetic material.)

How does chronic hepatitis B virus cause liver cancer? In patients with both chronic hepatitis B virus and liver cancer, the genetic material of hepatitis B virus is frequently found to be part of the genetic material of the cancer cells. It is thought, therefore, that specific regions of the hepatitis B virus genome (genetic code) enter the genetic material of the liver cells. This hepatitis B virus genetic material may then disrupt the normal genetic material in the liver cells, thereby causing the liver cells to become cancerous.

The vast majority of liver cancer that is associated with chronic hepatitis B virus occurs in individuals who have been infected most of their lives. In areas where hepatitis B virus is not always present (endemic) in the community (for example, the U.S.), liver cancer is relatively uncommon. The reason for this is that most of the people with chronic hepatitis B virus in these areas acquired the infection as adults. However, liver cancer can develop in individuals who acquired chronic hepatitis B virus in adulthood if there are other risk factors, such as chronic alcohol use or co-infection with chronic hepatitis C virus infection.

Hepatitis C infection

Hepatitis C virus (HCV) infection is also associated with the development of liver cancer. In fact, in Japan, hepatitis C virus is present in up to 75% of cases of liver cancer. As with hepatitis B virus, the majority of hepatitis C virus patients with liver cancer have associated cirrhosis (liver scarring). In several retrospective-prospective studies (looking backward and forward in time) of the natural history of hepatitis C, the average time to develop liver cancer after exposure to hepatitis C virus was about 28 years. The liver cancer occurred about eight to 10 years after the development of cirrhosis in these patients with hepatitis C. Several prospective European studies report that the annual incidence (occurrence over time) of liver cancer in cirrhotic hepatitis C virus patients ranges from 1.4 to 2.5% per year.

In hepatitis C virus patients, the risk factors for developing liver cancer include the presence of cirrhosis, older age, male gender, elevated baseline alpha-fetoprotein level (a blood tumor marker), alcohol use, and co-infection with hepatitis B virus. Some earlier studies suggested that hepatitis C virus genotype 1b (a common genotype in the U.S.) may be a risk factor, but more recent studies do not support this finding.

The way in which hepatitis C virus causes liver cancer is not well understood. Unlike hepatitis B virus, the genetic material of hepatitis C virus is not inserted directly into the genetic material of the liver cells. It is known, however, that cirrhosis from any cause is a risk factor for the development of liver cancer. It has been argued, therefore, that hepatitis C virus, which causes cirrhosis of the liver, is an indirect cause of liver cancer.

On the other hand, there are some chronic hepatitis C virus infected individuals who have liver cancer without cirrhosis. So, it has been suggested that the core (central) protein of hepatitis C virus is the culprit in the development of liver cancer. The core protein itself (a part of the hepatitis C virus) is thought to impede the natural process of cell death or interfere with the function of a normal tumor suppressor (inhibitor) gene (the p53 gene). The result of these actions is that the liver cells go on living and reproducing without the normal restraints, which is what happens in cancer.

Alcohol

Cirrhosis caused by chronic alcohol consumption is the most common association of liver cancer in the developed world. Actually, we now understand that many of these cases are also infected with chronic hepatitis C virus. The usual setting is an individual with alcoholic cirrhosis who has stopped drinking for ten years, and then develops liver cancer. It is somewhat unusual for an actively drinking alcoholic to develop liver cancer. What happens is that when the drinking is stopped, the liver cells try to heal by regenerating (reproducing). It is during this active regeneration that a cancer-producing genetic change (mutation) can occur, which explains the occurrence of liver cancer after the drinking has been stopped.

Patients who are actively drinking are more likely to die from non-cancer related complications of alcoholic liver disease (for example, liver failure). Indeed, patients with alcoholic cirrhosis who die of liver cancer are about 10 years older than patients who die of non-cancer causes. Finally, as noted above, alcohol adds to the risk of developing liver cancer in patients with chronic hepatitis C virus or hepatitis B virus infections.

Aflatoxin B1

Aflatoxin B1 is the most potent liver cancer-forming chemical known. It is a product of a mold called Aspergillus flavus, which is found in food that has been stored in a hot and humid environment. This mold is found in such foods as peanuts, rice, soybeans, corn, and wheat. Aflatoxin B1 has been implicated in the development of liver cancer in Southern China and Sub-Saharan Africa. It is thought to cause cancer by producing changes (mutations) in the p53 gene. These mutations work by interfering with the gene's important tumor suppressing (inhibiting) functions.

Drugs, medications, and chemicals

There are no medications that cause liver cancer, but female hormones (estrogens) and protein-building (anabolic) steroids are associated with the development of hepatic adenomas. These are benign liver tumors that may have the potential to become malignant (cancerous). Thus, in some individuals, hepatic adenoma can evolve into cancer.

Certain chemicals are associated with other types of cancers found in the liver. For example, thorotrast, a previously used contrast agent for imaging, caused a cancer of the blood vessels in the liver called hepatic angiosarcoma. Also, vinyl chloride, a compound used in the plastics industry, can cause hepatic angiosarcomas that appear many years after the exposure.

Hemochromatosis

Liver cancer will develop in up to 30% of patients with hereditary hemochromatosis. Patients at the greatest risk are those who develop cirrhosis with their hemochromatosis. Unfortunately, once cirrhosis is established, effective removal of excess iron (the treatment for hemochromatosis) will not reduce the risk of developing liver cancer.

Cirrhosis

Individuals with most types of cirrhosis of the liver are at an increased risk of developing liver cancer. In addition to the conditions described above (hepatitis B, hepatitis C, alcohol, and hemochromatosis), alpha 1 anti-trypsin deficiency, a hereditary condition that can cause emphysema and cirrhosis, may lead to liver cancer. Liver cancer is also strongly associated with hereditary tyrosinemia, a childhood biochemical abnormality that results in early cirrhosis.

Certain causes of cirrhosis are less frequently associated with liver cancer than are other causes. For example, liver cancer is rarely seen with the cirrhosis in Wilson's disease (abnormal copper metabolism) or primary sclerosing cholangitis (chronic scarring and narrowing of the bile ducts). It used to be thought that liver cancer is rarely found in primary biliary cirrhosis (PBC) as well. Recent studies, however, show that the frequency of liver cancer in PBC is comparable to that in other forms of cirrhosis.

What are the symptoms of liver cancer?

The initial symptoms (the clinical presentations) of liver cancer are variable. In countries where liver cancer is very common, the cancer generally is discovered at a very advanced stage of disease for several reasons. For one thing, areas where there is a high frequency of liver cancer are generally developing countries where access to healthcare is limited. For another, screening examinations for patients at risk for developing liver cancer are not available in these areas. In addition, patients from these regions actually have more aggressive liver cancer disease. In other words, the tumor usually reaches an advanced stage and causes symptoms more rapidly. In contrast, patients in areas of low liver cancer frequency tend to have liver cancer tumors that progress more slowly and, therefore, remain without symptoms longer.

Abdominal pain is the most common symptom of liver cancer and usually signifies a very large tumor or widespread involvement of the liver. Additionally, unexplained weight loss or unexplained fevers are warning signs of liver cancer in patients with cirrhosis. These symptoms are less common in individuals with liver cancer in the U.S. because these patients are usually diagnosed at an earlier stage. However, whenever the overall health of a patient with cirrhosis deteriorates, every effort should be made to look for liver cancer.

A very common initial presentation of liver cancer in a patient with compensated cirrhosis (no complications of liver disease) is the sudden onset of a complication. For example, the sudden appearance of ascites (abdominal fluid and swelling), jaundice (yellow color of the skin), or muscle wasting without causative (precipitating) factors (for example, alcohol consumption) suggests the possibility of liver cancer. What's more, the cancer can invade and block the portal vein (a large vein that brings blood to the liver from the intestine and spleen). When this happens, the blood will travel paths of less resistance, such as through esophageal veins. This causes increased pressure in these veins, which results in dilated (widened) veins called esophageal varices. The patient then is at risk for hemorrhage from the rupture of the varices into the gastrointestinal tract. Rarely, the cancer itself can rupture and bleed into the abdominal cavity, resulting in bloody ascites.

On physical examination, an enlarged, sometimes tender, liver is the most common finding. Liver cancers are very vascular (containing many blood vessels) tumors. Thus, increased amounts of blood feed into the hepatic artery (artery to the liver) and cause turbulent blood flow in the artery. The turbulence results in a distinct sound in the liver (hepatic bruit) that can be heard with a stethoscope in about one quarter to one half of patients with liver cancer. Any sign of advanced liver disease (for example, ascites, jaundice, or muscle wasting) means a poor prognosis. Rarely, a patient with liver cancer can become suddenly jaundiced when the tumor erodes into the bile duct. The jaundice occurs in this situation because both sloughing of the tumor into the duct and bleeding that clots in the duct can block the duct.

In advanced liver cancer, the tumor can spread locally to neighboring tissues or, through the blood vessels, to elsewhere in the body (distant metastasis). Locally, liver cancer can invade the veins that drain the liver (hepatic veins). The tumor can then block these veins, which results in congestion of the liver. The congestion occurs because the blocked veins cannot drain the blood out of the liver. (Normally, the blood in the hepatic veins leaving the liver flows through the inferior vena cava, which is the largest vein that drains into the heart.) In African patients, the tumor frequently blocks the inferior vena cava. Blockage of either the hepatic veins or the inferior vena cava results in a very swollen liver and massive formation of ascites. In some patients, as previously mentioned, the tumor can invade the portal vein and lead to the rupture of esophageal varices.

Regarding the distant metastases, liver cancer frequently spreads to the lungs, presumably by way of the blood stream. Usually, patients do not have symptoms from the lung metastases, which are diagnosed by radiologic (x-ray) studies. Rarely, in very advanced cases, liver cancer can spread to the bone or brain.

How is liver cancer diagnosed?

Blood tests

Liver cancer is not diagnosed by routine blood tests, including a standard panel of liver tests. This is why the diagnosis of liver cancer depends so much on the vigilance of the physician screening with a tumor marker (alpha-fetoprotein) in the blood and radiological imaging studies. Since most patients with liver cancer have associated liver disease (cirrhosis), their liver blood tests may not be normal to begin with. If these blood tests become abnormal or worsen due to liver cancer, this usually signifies extensive cancerous involvement of the liver. At that time, any medical or surgical treatment would be too late.

Sometimes, however, other abnormal blood tests can indicate the presence of liver cancer. Remember that each cell type in the body contains the full complement of genetic information. What differentiates one cell type from another is the particular set of genes that are turned on or off in that cell. When cells become cancerous, certain of the cell's genes that were turned off may become turned on. Thus, in liver cancer, the cancerous liver cells may take on the characteristics of other types of cells. For example, liver cancer cells sometimes can produce hormones that are ordinarily produced in other body systems. These hormones then can cause certain abnormal blood tests, such as a high red blood count (erythrocytosis), low blood sugar (hypoglycemia) and high blood calcium (hypercalcemia).

Another abnormal blood test, high serum cholesterol (hypercholesterolemia), is seen in up to 10% of patients from Africa with liver cancer. The high cholesterol occurs because the liver cancer cells are not able to turn off (inhibit) their production of cholesterol. (Normal cells are able to turn off their production of cholesterol.)

There is no reliable or accurate screening blood test for liver cancer. The most widely used biochemical blood test is alpha-fetoprotein (AFP), which is a protein normally made by the immature liver cells in the fetus. At birth, infants have relatively high levels of AFP, which fall to normal adult levels by the first year of life. Also, pregnant women carrying babies with neural tube defects may have high levels of AFP. (A neural tube defect is an abnormal fetal brain or spinal cord that is caused by folic acid deficiency during pregnancy.)

In adults, high blood levels (over 500 nanograms/milliliter) of AFP are seen in only three situations:
Liver cancer
Germ cell tumors (cancer of the testes and ovaries)
Metastatic cancer in the liver (originating in other organs)

Several assays (tests) for measuring AFP are available. Generally, normal levels of AFP are below 10 ng/ml. Moderate levels of AFP (even almost up to 500 ng/ml) can be seen in patients with chronic hepatitis. Moreover, many patients with various types of acute and chronic liver diseases without documentable liver cancer can have mild or even moderate elevations of AFP.

The sensitivity of AFP for liver cancer is about 60%. In other words, an elevated AFP blood test is seen in about 60% of liver cancer patients. That leaves 40% of patients with liver cancer who have normal AFP levels. Therefore, a normal AFP does not exclude liver cancer. Also, as noted above, an abnormal AFP does not mean that a patient has liver cancer. It is important to note, however, that patients with cirrhosis and an abnormal AFP, despite having no documentable liver cancer, still are at very high risk of developing liver cancer. Thus, any patient with cirrhosis and an elevated AFP, particularly with steadily rising blood levels, will either most likely develop liver cancer or actually already have an undiscovered liver cancer.

An AFP greater than 500 ng/ml is very suggestive of liver cancer. In fact, the blood level of AFP loosely relates to (correlates with) the size of the liver cancer. Finally, in patients with liver cancer and abnormal AFP levels, the AFP may be used as a marker of response to treatment. For example, an elevated AFP is expected to fall to normal in a patient whose liver cancer is successfully removed surgically (resected).

There are a number of other liver cancer tumor markers that currently are research tools and not generally available. These include des-gamma-carboxyprothrombin (DCP), a variant of the gamma-glutamyltransferase enzymes, and variants of other enzymes (for example, alpha-L-fucosidase), which are produced by normal liver cells. (Enzymes are proteins that speed up biochemical reactions.) Potentially, these blood tests, used in conjunction with AFP, could be very helpful in diagnosing more cases of liver cancer than with AFP alone.



Magnetic resonance imaging (MRI) can provide very clear images of the body. Its advantage over CT is that MRI can provide sectional views of the body in different planes. The technology has evolved to the point that the newer MRIs can actually reconstruct images of the biliary tree (bile ducts and gallbladder) and of the arteries and veins of the liver. (The biliary tree transports bile from the liver to the duodenum, the first part of the intestine.) MRI studies can be made even more sensitive by using intravenous contrast material (for example, gadolinium).

MRI scans are very expensive and there is tremendous variability in the quality of the images. The quality depends on the age of the machine and the ability of the patients to hold their breath for up to 15 to 20 seconds at a time. Furthermore, many patients, because of claustrophobia, cannot tolerate being in the MRI scanner. However, the current open MRI scanners generally do not provide as high quality images as the closed scanners do.

Advances in ultrasound, CT, and MRI technology have almost eliminated the need for angiography. An angiography procedure involves inserting a catheter into the femoral artery (in the groin) through the aorta, and into the hepatic artery, the artery that supplies blood to the liver. Contrast material is then injected, and X-ray pictures of the arterial blood supply to the liver are taken. An angiogram of liver cancer shows a characteristic blush that is produced by newly formed abnormal small arteries that feed the tumor (neovascularization).

What, then, is the best imaging study for diagnosing liver cancer? There is no simple answer. Many factors need to be taken into consideration. For example, is the diagnosis of liver cancer known or is the scan being done for screening? What is the expertise of doctors in the patient's area? What is the quality of the different scanners at a particular facility? Are there economic considerations? Does the patient have any other conditions that need to be considered, such as claustrophobia or kidney impairment? Does the patient have any hardware, for example, a pacemaker or metal prosthetic device? (The hardware would make doing an MRI impossible.)

If you live in Japan or Taiwan and have access to a radiologist or hepatologist with expertise in ultrasound, then it may be as good as a CT scan. Ultrasound is also the most practical (easier and cheaper) for regular screening (surveillance). In North America, a multi-phase spiral CT scan is probably the most accurate type of scan. However, for patients with impaired renal function or who have access to a state-of-the-art MRI scanner, the MRI may be the diagnostic scan of choice. Finally, keep in mind that the technology of ultrasound, CT, and MRI is ever evolving with the development of better machines and the use of special contrast materials to further characterize the tumors.

Liver biopsy or aspiration

In theory, a definitive diagnosis of liver cancer is always based on microscopic (histological) confirmation. However, some liver cancers are well differentiated, which means they are made up of nearly fully developed, mature liver cells (hepatocytes). Therefore, these cancers can look very similar to non-cancerous liver tissue under a microscope. Moreover, not all pathologists are trained to recognize the subtle differences between well-differentiated liver cancer and normal liver tissue. Also, some pathologists can mistake liver cancer for adenocarcinoma in the liver. An adenocarcinoma is a different type of cancer, and, as previously mentioned, it originates from outside of the liver. Most importantly, a metastatic adenocarcinoma would be treated differently from a primary liver cancer (liver cancer). Therefore, all of this considered, it is important that an expert liver pathologist review the tissue slides of liver tumors in questionable situations.

Tissue can be sampled with a very thin needle. This technique is called fine needle aspiration. When a larger needle is used to obtain a core of tissue, the technique is called a biopsy. Generally, radiologists, using ultrasound or CT scans to guide the placement of the needle, perform the biopsies or fine needle aspirations. The most common risk of the aspiration or biopsy is bleeding, especially because liver cancer is a tumor that is very vascular (contains many blood vessels). Rarely, new foci (small areas) of tumor can be seeded (planted) from the tumor by the needle into the liver along the needle track.

The aspiration procedure is safer than a biopsy with less risk for bleeding. However, interpretation of the specimen obtained by aspiration is more difficult because often only a cluster of cells is available for evaluation. Thus, a fine needle aspiration requires a highly skilled pathologist. Moreover, a core of tissue obtained with a biopsy needle is more ideal for a definitive diagnosis because the architecture of the tissue is preserved. The point is that sometimes a precise diagnosis can be important clinically. For example, some studies have shown that the degree of differentiation of the tumor may predict the patient's outcome (prognosis). That is to say, the more differentiated (resembling normal liver cells) the tumor is, the better the prognosis.

All of that said, in many instances, there is probably no need for a tissue diagnosis by biopsy or aspiration. If a patient has a risk factor for liver cancer (for example, cirrhosis, chronic hepatitis B, or chronic hepatitis C) and a significantly elevated alpha-fetoprotein blood level, the doctor can be almost certain that the patient has liver cancer without doing a biopsy. The patient and physician should always ask two questions before deciding on doing a liver biopsy:
Is this tumor most likely an liver cancer?
Will the biopsy findings change the management of the patient?

If the answer to both questions is yes, then the biopsy should be done. Finally, there are two other situations related to liver cancer in which a biopsy may be considered. The first is to characterize a liver abnormality (for example, a possible tumor) seen by imaging in the absence of risk factors for liver cancer or elevated alpha-fetoprotein. The second is to determine the extent of disease when there are multiple areas of abnormalities (possibly tumors) seen by imaging in the liver.

Overall, no blanket recommendation can be given regarding the need for liver biopsy or aspiration. The decision has to be made on an individual basis, depending on the treatment options and the expertise of the medical and surgical teams.

What is the natural history of liver cancer?

The natural history of liver cancer depends on the stage of the tumor and the severity of associated liver disease (for example, cirrhosis) at the time of diagnosis. For example, a patient with a 1 cm tumor with no cirrhosis has a greater than 50% chance of surviving three years, even without treatment. In contrast, a patient with multiple tumors involving both lobes of the liver (multicentric tumors) with decompensated cirrhosis (signs of liver failure) is unlikely to survive more than six months, even with treatment.

What are the predictors of a poor outcome? Our knowledge of the prognosis is based on studying many patients with liver cancer, separating out their clinical characteristics, and relating them to the outcome. Grouped in various categories, the unfavorable clinical findings include;
Population characteristics (demographics); male gender, older age, or alcohol consumption.
Symptoms; weight loss or decreased appetite.
Signs of impaired liver function; jaundice, ascites, or encephalopathy (altered mental state).
Blood tests; elevated liver tests (bilirubin or transaminase), reduced albumin, elevated AFP, elevated blood urea nitrogen (BUN), or low serum sodium.
Staging of tumor (based on imaging or surgical findings); more than one tumor, tumor over 3 cm (almost 1¼ inches), tumor invasion of local blood vessels (portal and/or hepatic vein), tumor spread outside of the liver (to lymph nodes or other organs).

There are various systems for staging liver cancer. Some systems look at clinical findings while others rely solely on pathological (tumor) characteristics. It makes the most sense to use a system that incorporates a combination of clinical and pathological elements. In any event, it is important to stage the cancer because staging can provide guidelines not only for predicting outcome (prognosis) but also for decisions regarding treatment.

The doubling time for a cancer is the time it takes for the tumor to double in size. For liver cancer, the doubling time is quite variable, ranging from one month to eighteen months. This kind of variability tells us that every patient with liver cancer is unique. Therefore, an assessment of the natural history and the evaluation of different treatments are very difficult. Nevertheless, in patients with a solitary liver cancer that is less than 3 cm, with no treatment, we can expect that 90% of the patients will survive (live) for one year, 50% for three years, and 20% for five years. In patients with more advanced disease, we can expect that 30% will survive for one year, 8% for three years, and none for five years.

What are the treatment options for liver cancer?

The treatment options are dictated by the stage of liver cancer and the overall condition of the patient. The only proven cure for liver cancer is liver transplantation for a solitary, small (<3cm) tumor. Now, many physicians may dispute this statement. They may argue that a small tumor can be surgically removed (partial hepatic resection) without the need for a liver transplantation. Moreover, they may claim that the one and three year survival rates for resection are perhaps comparable to those for liver transplantation.

However, most patients with liver cancer also have cirrhosis of the liver and would not tolerate liver resection surgery. But, they probably could tolerate the transplantation operation, which involves removal of the patient's entire diseased liver just prior to transplanting a donor liver. Furthermore, many patients who undergo hepatic resections will develop a recurrence of liver cancer elsewhere in the liver within several years. In fact, some experts believe that once a liver develops liver cancer, there is a tendency for that liver to develop other tumors at the same time (synchronous multicentric occurrence) or at a later time (metachronous multicentric occurrence).

The results of the various medical treatments (chemotherapy, chemoembolization, ablation, and proton beam therapy) remain disappointing. Moreover, for reasons noted earlier (primarily the variability in natural history), there have been no systematic study comparisons of the different treatments. As a result, individual patients will find that the various treatment options available to them depend largely on the local expertise.

How do we know if a particular treatment worked for a particular patient? Well, hopefully, the patient will feel better. However, a clinical response to treatment is usually defined more objectively. Thus, a response is defined as a decrease in the size of the tumor on imaging studies along with a reduction of the alpha-fetoprotein in the blood, if the level was elevated prior to treatment.

Sources : www.medicinenet.com

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