Squamous cell carcinoma

Squamous cell carcinoma

 

What is squamous cell carcinoma?

Squamous cell carcinoma is cancer that begins in the squamous cells, which are thin, flat cells that look like fish scales under the microscope. The word squamous came from the Latin squama, meaning "the scale of a fish or serpent" because of the appearance of the cells.

Squamous cells are found in the tissue that forms the surface of the skin, the lining of the hollow organs of the body, and the passages of the respiratory and digestive tracts. Thus, squamous cell carcinomas can actually arise in any of these tissues.

Squamous cell carcinoma of the skin occurs roughly one-quarter as often as basal cell carcinoma. Light-colored skin and a history of sun exposure are even more important in predisposing to this kind of cancer than to basal cell carcinoma. Men are affected more often than women. Patterns of dress and hairstyle may play a role. Women, whose hair generally covers their ears, develop squamous cell carcinomas far less often in this location than do men.

The earliest form of squamous cell carcinoma is called actinic (or solar) keratosis. Actinic keratoses appear as rough, red bumps on the scalp, face, ears, and backs of the hands. They often appear against a background of mottled, sun-damaged skin. They can be quite sore and tender, out of proportion to their appearance. In a patient with actinic keratoses, the rate at which one such keratosis may invade deeper in the skin to become a fully-developed squamous cell carcinoma is estimated to be in the range of 10%-20% over 10 years, though it may take less time. An actinic keratosis that becomes thicker and more tender raises the concern that it may have transformed into an invasive squamous cell carcinoma.

A rapidly-growing form of squamous cell carcinoma that forms a mound with a central crater is called a keratoacanthoma. While some consider this not a true cancer but instead a condition that takes care of itself, most pathologists consider it to be a form of squamous cell cancer and clinicians treat is accordingly.

Other forms of squamous cell carcinoma that have not yet invaded deeper into the skin include

·         actinic cheilitis, involving the lower lip with redness and scale, and blurring the border between the lip and the surrounding skin;

·         Bowen's disease, sometimes referred to as squamous cell carcinoma in situ. (The Latin words in situ refer to the presence of the cancer only in the superficial epidermis, without deeper involvement.) Bowen's disease appears as scaly patches on sun-exposed parts of the trunk and extremities; and

·         Bowenoid papulosis: These are genital warts that under the microscope look like Bowen's disease but behave like warts, not like cancers.

What are risk factors for developing squamous cell carcinoma?

The single most important factor in producing squamous cell carcinomas is sun exposure. Many such growths can develop from precancerous spots, called actinic or solar keratoses. These lesions appear after years of sun damage on parts of the body like the forehead and cheeks, as well as the backs of the hands. Sun damage takes many years to promote skin cancer. It is therefore common for people who stopped being "sun worshipers" in their 20s to develop precancerous or cancerous spots decades later.

Several rather uncommon factors may predispose to squamous cell carcinoma. These include exposure to arsenic, hydrocarbons, heat, or X-rays. Some squamous cell carcinomas arise in scar tissue. Suppression of the immune system by infection or drugs may also promote such growths. Some strains of HPV (the human papillomavirus responsible for causing genital warts) can promote development of squamous cell carcinoma in the anogenital region.

Can squamous cell carcinoma of the skin spread (metastasize)?

Yes. Unlike basal cell carcinomas, squamous cell carcinomas can metastasize, or spread to other parts of the body. These tumors usually begin as firm, skin-colored or red nodules. Squamous cell cancers that start out within solar keratoses or on sun-damaged skin are easier to cure and metastasize less often than those that develop in traumatic or radiation scars. One location particularly prone to metastatic spread is the lower lip. A proper diagnosis in this location is, therefore, especially important.

How is squamous cell carcinoma diagnosed?

As with basal cell carcinoma, doctors usually perform a biopsy to make a proper diagnosis. This involves taking a sample by injecting local anesthesia and punching out a small piece of skin using a circular punch blade. Usually the method used referred to as a punch biopsy. The skin that is removed is then examined under a microscope to check for cancer cells.

How is squamous cell carcinoma treated?

Techniques for treating squamous cell carcinoma are similar to those for basal cell carcinoma (for detailed descriptions, see above under treatment of basal cell carcinoma):

·         Curettage and desiccation: Dermatologists often prefer this method, which consists of scooping out the basal cell carcinoma by using a spoon like instrument called a curette. Desiccation is the additional application of an electric current to control bleeding and kill the remaining cancer cells. The skin heals without stitching. This technique is best suited for small cancers in non-crucial areas such as the trunk and extremities.

·         Surgical excision: The tumor is cut out and stitched up.

·         Radiation therapy: Doctors often use radiation treatments for skin cancer occurring in areas that are difficult to treat with surgery. Obtaining a good cosmetic result generally involves many treatment sessions, perhaps 25 to 30.

·         Cryosurgery: Some doctors trained in this technique achieve good results by freezing basal cell carcinomas. Typically, liquid nitrogen is applied to the growth to freeze and kill the abnormal cells.

·         Mohs micrographic surgery: Named for its pioneer, Dr. Frederic Mohs, this technique of removing skin cancer is better termed, "microscopically controlled excision." The surgeon meticulously removes a small piece of the tumor and examines it under the microscope during surgery. This sequence of cutting and microscopic examination is repeated in a painstaking fashion so that the basal cell carcinoma can be mapped and taken out without having to estimate or guess the width and depth of the lesion. This method removes as little of the healthy normal tissue as possible. Cure rate is very high, exceeding 98%. Mohs micrographic surgery is preferred for large basal cell carcinomas, those that recur after previous treatment, or lesions affecting parts of the body where experience shows that recurrence is common after treatment by other methods. Such body parts include the scalp, forehead, ears, and the corners of the nose. In cases where large amounts of tissue need to be removed, the Mohs surgeon sometimes works with a plastic (reconstructive) surgeon to achieve the best possible postsurgical appearance.

·         Medical therapy using creams that attack cancer cells (5-Fluorouracil--5-FU, Efudex, Fluoroplex) or stimulate the immune system (Aldara). These are applied several times a week for several weeks. They produce brisk inflammation and irritation. The advantages of this method is that it avoids surgery, lets the patient perform treatment at home, and may give a better cosmetic result. Disadvantages include discomfort, which may be severe, and a lower cure rate, which makes medical treatment unsuitable for treating most skin cancers on the face.

The possibility of metastasis makes it especially important to diagnose squamous cell carcinomas early and treat them adequately.

How is squamous cell carcinoma prevented?

Even more so than is the case with basal cell carcinoma, the key principles of prevention are minimizing sun exposure and getting regular checkups.

Common-sense preventive techniques are the same as for basal cell carcinoma and include

·         limiting recreational sun exposure;

·         avoiding unprotected exposure to the sun during peak radiation times (the hours surrounding noon);

·         wearing broad-brimmed hats and tightly-woven protective clothing while outdoors in the sun;

·         regularly using a waterproof or water-resistant sunscreen with UVA protection and SPF 30 or higher;

·         undergoing regular checkups and bringing any suspicious-looking or changing lesions to the attention of a doctor; and

·         avoiding the use of tanning beds and using a sunscreen with an SPF 30 and protection against UVA (long waves of ultraviolet light). Many people go out of their way to get an artificial tan before they leave for a sunny vacation, because they want to get a "base coat" to prevent sun damage. Even those who are capable of getting a tan, however, only get protection to the level of SPF 6, whereas the desired level is an SPF of 30. Those who only freckle get little or no protection at all from attempting to tan; they just increase sun damage. Sunscreen must be applied liberally and reapplied every two to three hours, especially after swimming or physical activity that promotes perspiration, which can weaken even sunscreens labeled as "waterproof."

Prevention from Skin Cancer

Prevention from Skin Cancer

Prevention

 

You can reduce your risk of getting skin cancer.

·         Limit sun exposure. Attempt to avoid the sun's intense rays between 10 a.m. and 2 p.m.

·         Apply sunscreen frequently. Use a sunscreen with Sun Protection Factor (SPF) of at least 15 both before and during sun exposure. Select products that block both UVA and UVB light. The label will tell you.

·         If you are likely to sunburn, wear long sleeves and a wide-brimmed hat.

·         Avoid artificial tanning booths.

·         Conduct periodic skin self-examinations

Skin self-examination

Monthly self-examination improves your chances of finding a skin cancer early, when it has done a minimum of damage to your skin and can be treated easily. Regular self-exam helps you recognize any new or changing features.

·         The best time to do a self-exam is right after a shower or bath.

·         Do the self-exam in a well-lighted room; use a full-length mirror and a handheld mirror.

·         Learn where your moles, birthmarks, and blemishes are, and what they look like.

·         Each time you do a self-exam, check these areas for changes in size, texture, and color, and for ulceration. If you notice any changes, call your primary-care provider or dermatologist.

Check all areas of your body, including "hard-to-reach" areas. Ask a loved one to help you if there are areas you can't see.

·         Look in the full-length mirror at your front and your back (use the handheld mirror to do this). Raise your arms and look at your left and right sides.

·         Bend your elbows and look carefully at your palms, your forearms (front and back), and upper arms.

·         Examine the backs and fronts of your legs. Look at your buttocks (including the area between the buttocks) and your genitals (use the handheld mirror to make sure you see all skin areas).

·         Sit down and examine your feet carefully, including the soles and between the toes.

·         Look at your scalp, face, and neck. You may use a comb or blow dryer to move your hair while examining your scalp.

Skin Cancer

Basal cell carcinoma

What is basal cell carcinoma?

Basal cell carcinoma is the most common form of skin cancer and accounts for more than 90% of all skin cancer in the U.S. These cancers almost never spread (metastasize) to other parts of the body. They can, however, cause damage by growing and invading surrounding tissue.

What are risk factors for developing basal cell carcinoma?

Light-colored skin, sun exposure, and age are all important factors in the development of basal cell carcinomas. People who have fair skin and are older have higher rates of basal cell carcinoma. About 20% of these skin cancers, however, occur in areas that are not sun-exposed, such as the chest, back, arms, legs, and scalp. The face, however, remains the most common location for basal cell lesions. Weakening of the immune system, whether by disease or medication, can also promote the risk of developing basal cell carcinoma. Other risk factors include

·         exposure to sun. There is evidence that, in contrast to squamous cell carcinoma, basal cell carcinoma is promoted not by accumulated sun exposure but by intermittent sun exposure like that received during vacations, especially early in life. According to the U.S. National Institutes of Health, ultraviolet (UV) radiation from the sun is the main cause of skin cancer. The risk of developing skin cancer is also affected by where a person lives. People who live in areas that receive high levels of UV radiation from the sun are more likely to develop skin cancer. In the United States, for example, skin cancer is more common in Texas than it is in Minnesota, where the sun is not as strong. Worldwide, the highest rates of skin cancer are found in South Africa and Australia, which are areas that receive high amounts of UV radiation.

·         age. Most skin cancers appear after age 50, but the sun's damaging effects begin at an early age. Therefore, protection should start in childhood in order to prevent skin cancer later in life.

·         exposure to ultraviolet radiation in tanning booths. Tanning booths are very popular, especially among adolescents, and they even let people who live in cold climates radiate their skin year-round.

·         therapeutic radiation, such as that given for treating other forms of cancer.

What does basal cell carcinoma look like?

A basal cell carcinoma usually begins as a small, dome-shaped bump and is often covered by small, superficial blood vessels called telangiectases. The texture of such a spot is often shiny and translucent, sometimes referred to as "pearly." It is often hard to tell a basal cell carcinoma from a benign growth like a flesh-colored mole without performing a biopsy. Some basal cell carcinomas contain melanin pigment, making them look dark rather than shiny.

Superficial basal cell carcinomas often appear on the chest or back and look more like patches of raw, dry skin. They grow slowly over the course of months or years.

Basal cell carcinomas grow slowly, taking months or even years to become sizable. Although spread to other parts of the body (metastasis) is very rare, a basal cell carcinoma can damage and disfigure the eye, ear, or nose if it grows nearby.

How is basal cell carcinoma diagnosed?

To make a proper diagnosis, doctors usually remove all or part of the growth by performing a biopsy. This usually involves taking a sample by injecting a local anesthesia and scraping a small piece of skin. This method is referred to as a shave biopsy. The skin that is removed is then examined under a microscope to check for cancer cells.

How is basal cell carcinoma treated?

There are many ways to successfully treat a basal cell carcinoma with a good chance of success of 90% or more. The doctor's main goal is to remove or destroy the cancer completely with as small a scar as possible. To plan the best treatment for each patient, the doctor considers the location and size of the cancer, the risk of scarring, and the person's age, general health, and medical history.

Methods used to treat basal cell carcinomas include:

·         Curettage and desiccation: Dermatologists often prefer this method, which consists of scooping out the basal cell carcinoma by using a spoon like instrument called a curette. Desiccation is the additional application of an electric current to control bleeding and kill the remaining cancer cells. The skin heals without stitching. This technique is best suited for small cancers in non-crucial areas such as the trunk and extremities.

·         Surgical excision: The tumor is cut out and stitched up.

·         Radiation therapy: Doctors often use radiation treatments for skin cancer occurring in areas that are difficult to treat with surgery. Obtaining a good cosmetic result generally involves many treatment sessions, perhaps 25 to 30.

·         Cryosurgery: Some doctors trained in this technique achieve good results by freezing basal cell carcinomas. Typically, liquid nitrogen is applied to the growth to freeze and kill the abnormal cells.

·         Mohs micrographic surgery: Named for its pioneer, Dr. Frederic Mohs, this technique of removing skin cancer is better termed "microscopically controlled excision." The surgeon meticulously removes a small piece of the tumor and examines it under the microscope during surgery. This sequence of cutting and microscopic examination is repeated in a painstaking fashion so that the basal cell carcinoma can be mapped and taken out without having to estimate or guess the width and depth of the lesion. This method removes as little of the healthy normal tissue as possible. Cure rate is very high, exceeding 98%. Mohs micrographic surgery is preferred for large basal cell carcinomas, those that recur after previous treatment, or lesions affecting parts of the body where experience shows that recurrence is common after treatment by other methods. Such body parts include the scalp, forehead, ears, and the corners of the nose. In cases where large amounts of tissue need to be removed, the Mohs surgeon sometimes works with a plastic (reconstructive) surgeon to achieve the best possible postsurgical appearance.

·         Medical therapy using creams that attack cancer cells (5-Fluorouracil--5-FU, Efudex, Fluoroplex) or stimulate the immune system.These are applied several times a week for several weeks. They produce brisk inflammation and irritation. The advantages of this method is that it avoids surgery, lets the patient perform treatment at home, and may give a better cosmetic result. Disadvantages include discomfort, which may be severe, and a lower cure rate, which makes medical treatment unsuitable for treating most skin cancers on the face.

How is basal cell carcinoma prevented?

Avoiding sun exposure in susceptible individuals is the best way to lower the risk for all types of skin cancer. Regular surveillance of susceptible individuals, both by self-examination and regular physical examination, is also a good idea for people at higher risk. People who have already had any form of skin cancer should have regular medical checkups.

Common sense preventive techniques include

·         limiting recreational sun exposure;

·         avoiding unprotected exposure to the sun during peak radiation times (the hours surrounding noon);

·         wearing broad-brimmed hats and tightly-woven protective clothing while outdoors in the sun;

·         regularly using a waterproof or water resistant sunscreen with UVA protection and SPF 30 or higher;

·         undergoing regular checkups and bringing any suspicious-looking or changing lesions to the attention of the doctor; and

·         avoiding the use of tanning beds and using a sunscreen with an SPF of 30 and protection against UVA (long waves of ultraviolet light.). Many people go out of their way to get an artificial tan before they leave for a sunny vacation, because they want to get a "base coat" to prevent sun damage. Even those who are capable of getting a tan, however, only get protection to the level of SPF 6, whereas the desired level is an SPF of 30. Those who only freckle get little or no protection at all from attempting to tan; they just increase sun damage. Sunscreen must be applied liberally and reapplied every two to three hours, especially after swimming or physical activity that promotes perspiration, which can weaken even sunscreens labeled as "waterproof."

Toxic Hepatitis

Toxic Hepatitis

What is toxic hepatitis?

Toxic hepatitis is an inflammation of the liver caused by chemicals. Many chemicals that are intentionally or unintentionally inhaled or consumed can have toxic effects on the liver. Among these chemicals are drugs, industrial solvents and pollutants. Virtually every drug imaginable has at one time or another been indicated as a cause of toxic hepatitis.

Toxins can occasionally cause chronic liver disease and even cirrhosis if the use of the drug is not stopped.

Do all toxins affect the liver in the same manner?

Toxins that can damage the liver have been divided into two groups:

Predictable, those that are known to cause toxic hepatitis and liver damage with sufficient exposure to one or more of these chemicals. Examples of chemicals found in this group are cleaning solvents, carbon tetrachloride and the pain reliever acetaminophen.

Unpredictable, those toxins that damage the liver in a very small proportion of individuals exposed to the chemical. Unpredictable injury produced by most drugs is very poorly understood but recent data suggest that a toxic response to a drug probably depends on the kind of enzyme a person inherits to metabolize the drug.

Why is the liver susceptible to injury by chemicals?

The liver is susceptible to injury by chemicals because it plays a fundamental role in chemical metabolism. The liver has the unique job of processing almost all chemicals and drugs that enter the blood stream and removing the chemicals that are difficult for the kidneys to excrete. The liver turns these chemicals into products that can be eliminated from the body through bile or urine. However, during this chemical process in the liver, unstable highly toxic products are sometimes produced; these highly toxic products can attack and injure the liver.

Regular alcohol consumption will likely enhance the chance of drug toxicity especially in the case of acetaminophen. Therefore, alcohol should not be consumed when using medications.

What are the symptoms of toxic hepatitis?

Clinically, toxic hepatitis can resemble any form of acute or chronic liver disease, such as viral hepatitis or bile-duct obstruction. Symptoms such as nausea, vomiting, fever, jaundice as well as liver blood tests and liver biopsy findings are often identical to viral hepatitis. On the other hand, symptoms like fever, abdominal pain and jaundice can mimic other liver conditions, such as stones blocking the bile ducts.

How is the diagnosis of toxic hepatitis made?

At present there is no clear test to prove the diagnosis. Therefore, the diagnosis is made based on a thorough assessment of a patient. First, the doctor must pay close attention to all drugs used (prescribed or over the counter ones including herbal remedies), as well as the environmental and occupational exposures to chemicals of each individual with liver disease.

The doctor must also consider the time of exposure. Some forms of chemical liver injury will occur within days to weeks of the exposure; however, sometimes it takes many months of regular ingestion of a drug before liver injury becomes apparent.

How is toxic hepatitis treated?

If an individual has toxic hepatitis, the drug(s) should be immediately discontinued and further exposure to the offending chemical prevented. Removal of the offending chemical or drug leads to rapid improvement often within days but sometimes several months may elapse before improvement is noted, even if chronic liver disease has already developed. No other specific therapy is needed.

Fatty Liver Disease

Fatty Liver Disease

What is a fatty liver?

A fatty liver is the result of the accumulation of excess fat in liver cells. Fatty tissue slowly builds up in the liver when a person’s diet exceeds the amount of fat his or her body can handle. A person has a fatty liver when fat makes up at least 5-10% of the liver. Simple fatty liver can be a completely benign condition and usually does not lead to liver damage. However, once there is a buildup of simple fat, the liver becomes vulnerable to further injury, which may result in inflammation and scarring of the liver.

What causes fatty liver disease?

The most common cause of fatty liver disease in Canada is obesity. Whereas several decades ago obesity was not very common, according to current statistics more than 50% of Canadians are overweight. It is estimated that 75% of obese individuals are at risk of developing a simple fatty liver. Up to 23% of obese individuals are at risk of developing fatty liver with inflammation.

Besides obesity, nutritional causes of fatty liver disease are:

starvation and protein malnutrition,

long term use of total parenteral nutrition (a feeding procedure that involves infusing nutrients directly into the blood stream),

intestinal bypass surgery for obesity,

rapid weight loss.

Certain conditions often accompany and may contribute to fatty liver disease:

• diabetes mellitus,
• hyperlipidemia (elevated lipids in the blood),
• insulin resistance and high blood pressure.

Other causes include:

• genetic factors,
• drugs and chemicals such as alcohol, corticosteroids, tetracycline and carbon tetrachloride.

How do we define “Overweight” and “Obese”?

Although many people feel they could lose some weight, few would consider themselves obese. A widely-used measure to define “overweight” and “obese” is the Body Mass Index (BMI). A BMI is a calculation based on your height and weight that gives a number that reflects either a healthy or unhealthy weight. A BMI of 18 – 25 is within the healthy range for most people, 25 – 30 is classified as overweight and over 30 is obese. Different ethnic groups may differ slightly – for example, in Asian populations the healthy BMI is lower, ranging from 18 - 23.

Does the size of your waist matter?

Excess abdominal fat is associated with fatty liver disease and other health risks such as diabetes. Waist measurements - which differ according to gender - are used to identify the health risks associated with excess abdominal fat: For men, health risks increase if your waist circumference is more than 102 cm (40 in.). For women, the risks increase if your waist circumference is more than 88 cm (35 in.).

What is my BMI?

You can use the following formula to calculate your BMI:
BMI = weight in kilograms divided by (height in metres)2

Example: for someone who is 1.70 metres tall who weighs 80 kilograms:
BMI  = 80 divided by (1.70)2 = 27.7

How does fat get into the liver?

Fat from a person’s diet is usually metabolized by the liver and other tissues. If the amount of fat exceeds what is required by the body, fat is stored in the fatty tissue. Other reasons for accumulation of fat in the liver could be the transfer of fat from other parts of the body or the inability of the liver to change it into a form that can be eliminated.

What is NASH?

NASH represents the more severe end of the spectrum of non-alcoholic fatty liver disease. NASH stands for NonAlcoholic Steatohepatitis. Steatohepatitis means fatty liver with inflammation, in other words, ongoing damage similar to alcoholic liver disease but in this case it occurs in people who do not drink alcohol or drink minimally.

NASH differs from the simple accumulation of fat in the liver, which is a completely benign condition. Up to 20% of adults with NASH develop cirrhosis and up to 11% may experience liver-related deaths. Many individuals develop chronic liver failure and require liver transplantation. The prevalence of NASH is 2-6% in the general population.

Can children develop fatty liver disease?

Fatty liver disease is now becoming evident in children, due in large part to an alarming increase in childhood obesity. It is estimated that one in 10 Canadian children is overweight - a number that has almost tripled in the last decade. Fatty liver disease affects almost 3% of children and 22 – 53% of obese children. Fatty liver disease can be found in children as young as four years of age.

What are the symptoms of fatty liver disease?

In general, people with fatty liver disease have no symptoms. However, some people report discomfort in the abdomen at the level of the liver, fatigue, a general feeling of being unwell and vague discomfort.

How is fatty liver disease diagnosed?

Fatty liver disease is usually suspected in patients who have an enlarged liver or abnormal liver tests. An ultrasound of the liver can suggest the presence of a fatty liver. In some cases, your doctor may advise a liver biopsy, a procedure where the physician inserts a needle into the liver and extracts a sample tissue, which is then examined under a microscope.

The treatment of fatty liver disease is related to the cause. At this time, it is not possible to predict which patients will develop NASH. Once there is a buildup of simple fat however, the liver becomes vulnerable to further injury, which may result in liver inflammation and scarring (NASH).

Patients who are obese are advised to achieve a gradual and sustained weight loss through proper nutrition and exercise. Patients with diabetes and high lipids in their blood have to improve their sugar control and lower lipids levels. Usually, a low fat, low calorie diet is recommended along with insulin or medications to lower blood sugar in people with diabetes.

For patients with NASH who are not overweight and not diabetic, a low fat diet is often recommended. It is also recommended that people avoid drinking alcohol since it can cause and contribute to fatty liver disease. Patients with fatty liver disease should see their primary healthcare providers on a regular basis.

Currently, there is no medication proven to effectively treat fatty liver disease. Since it is now such a common condition, it has raised a lot of interest in the scientific community. There are now a number of clinical trials looking at various treatments of fatty liver disease.

Can fatty liver disease be prevented?

By choosing a healthy life style, you may prevent obesity - the number one reason for fatty liver disease. Please remember that a healthy diet and exercise are important components of any weight-loss regimen. The following are some suggestions for preventing fatty liver disease:

• Choose to lead a healthy lifestyle.
• If you are overweight, strive for a gradual and sustained weight loss.
• Eat a well-balanced diet that is low in saturated fats and high in fibre.
• Introduce exercise into your routine, at least four times a week. 
• You can enjoy walking, swimming, gardening, stretching.
•  Avoid alcohol.

LIVER CANCER

LIVER CANCER

What causes liver cancer?

• Many factors may play a role in the development of cancer.
• Because the liver filters blood from all parts of the body, cancer cells from elsewhere can lodge in the liver and start to grow.
• Cancers that begin in the gut often spread to the liver. The ability of the liver to regenerate may also be linked to the development of liver cancers. 

How are liver cancers classified?

There are many types of liver tumours, only some of which are cancers. The most important classification is whether the tumours are benign (relatively harmless) or malignant (capable of spreading from the liver and thus more serious).


Benign Tumours

Hemangioma is the most common type of benign liver tumour. It is an abnormal growth of blood vessels of the liver that begins in the fetus. More than 10% of the normal population has hemanigomas in the liver. Most people with hemangiomas have no symptoms and require no treatment. Some hemangiomas may rarely enlarge and bleed in which case they may require surgical removal.

Hepatic adenomas are benign tumours of liver cells. Most do not cause symptoms and do not require treatment. However, if they are large they may cause pain or blood loss and may need to be removed. Hepatic adenomas occur more frequently in women and seem to be triggered in some cases by the birth control pill or by pregnancy.

Focal nodular hyperplasia (FNH) is a tumour-like growth of several cell types. Although FNH tumours are benign, it can be hard to distinguish them from liver cancers.

Malignant Tumours

The most common form of primary liver cancer (cancer that starts in the liver) in adults is called hepatocellular carcinoma (HCC). It is a cancer of liver cells. This type of cancer can have different growth patterns. Some begin as a single tumour that grows larger. It may spread to other parts of the liver in later stages of the disease.

Liver cancer may also develop in more than one site in the liver and may grow into multiple tumours. This pattern is most often seen in people with liver cirrhosis.

Another liver cancer is called cholangiocarcinoma. It originates in the small bile ducts which are tubes that carry bile to the gall bladder.

Most often, however, when cancer occurs in the liver, it did not start there, but spread to the liver from a cancer that began somewhere else in the body. These types of cancers are named after the place where they began (primary site) and are considered secondary liver cancers or cancer metastases. For example, cancer that started in the lung and spread to the liver is called metastatic lung cancer with spread to the liver. Secondary liver cancers are 30 times more prevalent than primary liver cancers. 

What are the risk factors associated with liver cancer?

In the absence of chronic liver disease liver cancer is rare. However, in patients with underlying liver disease, liver cancer may be quite common. The exact cause of liver cancer is not known. Scientists have identified many risk factors that can make someone more likely to develop liver cancer:   

Among those with chronic liver disease, men are more likely to develop liver cancer than are women. The reason for this is unknown. 

Viral infection of the liver: Chronic infection with either hepatitis B or hepatitis C may lead to the development of cancer.

Certain types of inherited liver disease such as hemochromatosis, which results in accumulation of too much iron in the liver, as well as alpha-1 antitrypsin deficiency, and tyrosinemia can lead to the development of liver cancer later in life.

Cirrhosis is the formation of scar tissue in the liver. This can often lead to cancer. Major causes of liver cirrhosis are alcohol use, chronic hepatitis B and C, and non-alcoholic steatohepatitis (NASH). Most causes of cirrhosis are also associated with the development of liver cancer. 

Alcohol: excessive alcohol use is a known risk factor for development of alcoholic cirrhosis and liver cancer.

Obesity increases the risk of liver cancer in those patients in whom it causes liver disease. 

Tobacco use increases the risk of liver cancer if you already have chronic liver disease. 

Anabolic steroids: long-term use of anabolic steroids can increase the risk of liver cancer.

What is the incidence of primary liver cancers?

Primary liver cancers account for less than 1% of all cancers in North America whereas in Africa, Southeast Asia, and China, they may account for up to 50% of cancers. The high prevalence of people carrying the hepatitis B virus and having liver cirrhosis may account for this geographic discrepancy.

What are the symptoms of liver cancer?

In the early stages, liver cancer does not cause symptoms. Some common symptoms of advanced liver cancer include: 

weight loss 

loss of appetite                

abdominal pain

jaundice

fluid in the abdomen

How is liver cancer detected? 

ultrasound 

blood test to check for increased levels of alpha-fetoprotein (AFP) 

computer tomography scan (CT)

magnetic resonance imaging (MRI)

Are there treatments for liver cancer?

The treatment of HCC depends on the stage and the speed of tumour growth. Small primary cancers of the liver are curable. Cure rates generally decrease as the tumour size increases. Treatment of liver cancer may involve surgery, radiation therapy and chemotherapy or liver transplantation. 

Surgery 

Surgery can remove a small liver tumour through a procedure known as resection, in which a piece of the liver containing the tumour is removed. If all of the cancer can be removed, a patient has a good outlook for survival. If the cancer is too large, is found in many different parts of the liver, or has spread beyond the liver, it may not be possible to remove it completely. For many people with cirrhosis there is insufficient healthy liver to allow removal of even a small part of the liver. In this case, surgery is not an option.

Tumour ablation or embolization

Ablation refers to methods that destroy the tumour without removing it. Examples include destroying the tumour by using high-energy radio waves (RFA), freezing it with a very cold metal probe, or injecting alcohol directly into the tumour to kill cancer cells. The blood supply to the cancer can be reduced by blocking the artery that feeds the cancer or by injecting materials that plug the artery. This is called embolization. Because this kind of treatment also reduces blood supply to the normal liver tissue, it can be dangerous for people with diseases such as hepatitis or cirrhosis.

Chemoembolization involves combining embolization with chemotherapy. Chemoembolization prolongs life in patients in whom cure is not possible.

Radiation therapy is treatment that uses high-energy rays (such as x-rays) to kill or shrink cancer cells. This type of treatment may be used to shrink a liver tumour or to provide relief from symptoms, but it does not cure the liver cancer.

Chemotherapy refers to the use of drugs to kill cancer cells. Usually the drugs are given into a vein or by mouth. Liver cancer does not respond well to most chemotherapy drugs.

Are people with liver cancer considered for transplantation?

Most cancers of the liver begin elsewhere in the body and are spread to the liver. These cancers are not curable through liver transplantation. Tumours that originate in the liver are usually detected in an advanced stage. They are also rarely cured by a liver transplant. If the cancer is small and confined to the liver, a transplant may be considered.

Are there treatments for secondary liver cancers?

The liver is involved in approximately 1/3 of all cancers and often those that begin in the gastrointestinal tract, colon, pancreas, stomach, breast and lung. The risk factors involved in this type of liver cancer are numerous given that the cancers originate elsewhere. The prognosis for patients with secondary liver tumors depends on the primary site of malignancy. In general, patients do not live longer than one year from the diagnosis of hepatic metastases. Treatments remain unsatisfactory but include chemotherapy, immunotherapy, and embolization.

Can liver cancer be prevented?

Prevention is the best defence against liver cancer. Worldwide, the most common risk factor for liver cancer is chronic hepatitis B and C infection. Therefore, prevention of these forms of liver disease is important. The Canadian Liver Foundation recommends that all children as well as adults at high risk should be vaccinated against hepatitis B. Since there is no vaccine against hepatitis C, it is important to prevent the spread of this disease, and to identify and assess for treatment all those who are already infected with the hepatitis C virus.

Alcohol consumption should be limited to no more than one to two standard drinks per day. Drinking alcohol every day as well as binge drinking can be harmful to your liver. If you already have a liver disease, the safest amount of alcohol is no alcohol at all.

It is important to maintain a well balanced diet and introduce exercise into your daily routine.

People at high risk of liver cancer should be screened regularly to increase the chances of early detection. Early detection of small liver cancers greatly enhances the chances of cure using techniques such as radiofrequency ablation. Everyone who is at risk for the development of primary liver cancer should undergo regular screening by ultrasonography at six monthly intervals. Finding of abnormal screening ultrasound results should prompt a visit to a liver specialist.

What does the future hold?

The Canadian Liver Foundation funds research into the causes, diagnosis, prevention and treatment of all forms of liver disease including liver cancer. Scientists are looking for the causes of liver cancer, ways to prevent it and to improve treatments. Control of viral hepatitis infection and better treatments for chronic hepatitis could prevent about half of liver cancer cases worldwide. New methods that combine treatments with surgery are being studied.