Sabtu, 16 April 2011

Causes of Cancer

Cancer is a class of disease characterized by out-of-control cell growth. With more than 200 different types of cancer, one can develop it in virtually any organ of the body. Research states that there are more than 60 different organs in the body where cancer can develop.

Typically, one form of cancer will develop in certain areas of the body. However, since cancer can develop from almost any type of cell, it is also possible that more than one type of cancer can develop in any one part of the body. For example, one can develop pleural mesothelioma or pericardial mesothelioma, two different types of cancer, even though they both form in, and around, cardiac muscles.

Ultimately, cancer is the result of cells that grow uncontrollably and do not die. Whereas normal cells in the body go through life stages of growth, division and death, cancer cells do not complete this cycle. Programmed cell death is called apoptosis, and when this process begins to weaken, cancer can form. Since cancer cells do not die, they continue to grow and divide, causing a mass of abnormal cells to develop, eventually causing cancer.

Cancer is a complex group of diseases with numerous causes. Genetic factors, smoking, diet and physical activity, certain infections and exposure to different types of chemicals and radiation, such as asbestos, are all linked to the development of cancer.

In this section, one can learn more about the known causes of cancer and educate themselves on how to better prevent this disease from developing in themselves or their loved ones.

Genetics and Cancer: Some types of cancer are known to run in certain families’ histories. However, most cancers are not linked to genes. Therefore, one does not literally inherit the disease from their parents. This section uncovers the links between genes and cancer, as well as genetic testing and how it is used.

Tobacco and Cancer: This section relates tobacco usage with cancer and provides resources for those interested in quitting smoking. It also touches on the synergistic effects of smoking and exposure to asbestos.

Diet and Physical Activity: Learn how diet, physical activity, lifestyle choices and alcohol use may affect one’s risk of developing cancer.

Sun and UV Exposure: This section connects excessive sun exposure to cancer. It also provides resources and ways to protect oneself from harmful UV rays.

Other Carcinogens: Some environmental causes may be lurking in one’s home or at work. This section helps individuals understand and identify possible pollutants in the air.


American Cancer Society

Cancer Myths and Misconceptions

Myths can cause hypochondriacs and the like to unnecessarily worry about their health. Frightening claims on the internet circulate daily about new products causing cancer. Besides most of the claims being bogus, many of these accusations cause people to worry about their health, and the health of their families for no reason. One should get all the facts before jumping to conclusions. Below is a list of common myths about cancer and whether or not there’s any truth to them.

Myth: Deodorant can cause breast cancer.

Fact: Although a few reports have suggested that some deodorant products contain harmful substances such as aluminum compounds and parabens that can be absorbed through the skin, there’s no conclusive evidence linking the use of underarm antiperspirants with breast cancer. According to the National Cancer Institute, no clinical studies have yet to link these products with breast cancer.

If someone is still concerned about using deodorants that contain substances such as aluminum compounds and parabens, they can certainly find natural products that do not contain those chemicals.

Myth: Microwaving food in plastic containers releases harmful, cancer causing substances.

Fact: Microwave-safe plastics and wraps do not leak harmful chemicals into food.

However, the Food and Drug Administration (FDA) states that plastic containers produced with no intention of being used in a microwave can melt and potentially leak chemicals into food. Things such as margarine tubs and similar containers should not be put into a microwave to heat up food. It is important to check to see that the container being used in a microwave is labeled microwave-safe.

Myth: People diagnosed with cancer should not eat sugar, since it can cause cancer to grow faster.

Fact: Sugar does not make cancer grow faster. Just like healthy cells, cancer cells depend on blood sugar (glucose) for energy. However, giving more sugar to cancer cells does not speed their growth. Likewise, denying cancer cells sugar will not impede their growth.

This misconception may be due in part to a misunderstanding of positron emission tomography (PET) scans, which use a small amount of radioactive tracer – typically a form of glucose. Since cancer cells use more energy, they absorb a greater amount of this tracer. For this reason, people have concluded that cancer cells grow faster on sugar, but it is simply not true.

Myth: Good people don’t get cancer.

Fact: In the days of old, it was a common belief that illness was a punishment associated with a person who did bad things. As a matter of fact, some cultures still uphold those beliefs. However there is absolutely no evidence whatsoever to prove you can get cancer simply because you deserve it. To test how crazy this theory is, try explaining why a newborn or young child would deserve cancer.

Myth: Cancer is contagious.

Fact: Unlike a cold, a person cannot catch cancer from someone who has it.

That being said, there is no need to avoid someone who has cancer. In fact, a loved one touching, and spending more time with someone who has cancer could be more beneficial than not.

Although cancer itself is not contagious, some viruses, which are contagious have been known to cause cancer. Examples of these viruses are:

  • Human papillomavirus (HPV): a sexually transmitted disease – that can cause cervical cancer among other forms of cancer.
  • Hepatitis C: a virus transmitted through sexual intercourse, or contracted through infected intravenous (IV) needles. Hepatitis C can cause liver cancer.

One should talk to a doctor about ways to protect themselves from these viruses.

Myth: Grilled meats can cause cancer

Fact: It has been proven that eating grilled, or pan fried meat can increase a person’s risk of cancer.

When meat is grilled a harmful chemical called heterocyclicamines are created. Research suggests that since a greater quantity of this chemical is found in meats cooked well done or burnt, to either limit the amount of time the meat is spent on the grill, and or just cut off the burnt pieces altogether. They also recommend marinating and precooking meats in a microwave safe container prior to cooking meat elsewhere. Keep in mind grilling foods such as fruits and veggies are safe and healthy.


Mayo Clinic Staff, . "Cancer causes: Popular myths about the causes of cancer." Mayo Clinic 16 May 2009: n. pag. Web. Retrieved 8 Apr 2011 by Mayo Clinic.

Breast Cancer

Breast cancer is the second most common cancer among women in the United States. While men have been diagnosed with this cancer, women are 100 times more likely to develop breast cancer over men.

Breast cancer is a type of cancer that forms in tissues of the breast. It usually originates in the ducts (tubes that carry milk to the nipple) but it can also form in the lobules, the glands that produce milk. Most breast lumps are benign (not cancerous), however some may need to be sampled under a microscope to make certain that they are not cancer.

Certain women are at higher risks of getting breast cancer than others. Age, family history and genetic makeup are not things that can be altered; however there are external risk factors that can be controlled. These risks include:

  • Drinking more than two alcoholic beverages per day
  • Bearing children after the age of 30 (or never having children at all)
  • Taking the drug diethylstilbestrol (DES) to prevent miscarriages
  • Obesity (thought to trigger excess estrogen production)
  • Receiving hormone replacement therapy (HRT)
  • Receiving radiation therapy to the chest

Asbestos and Breast Cancer

Environmental factors may play a role in breast cancer as well. The correlation between breast cancer and mesothelioma is uncertain. Conversely, studies have shown a link to higher rates of breast cancer in women that were exposed to environmental toxin asbestos. There is not enough evidence to indicate that this is a causal relationship, but it could suggest that long-term asbestos exposure may be associated with higher risks of breast cancer.

A study of British factory workers who were diagnosed with cancer found a slight increase in breast cancer diagnoses in female factory workers who were exposed to asbestos in the workforce for two or more years. Another British study examined 178 females for the presence of asbestos. The fiber was prevalent in the lungs of 30 percent of all women in the study, yet the bulk of the females found with asbestos were found in the subgroup of women who had been diagnosed with breast cancer. Of the 82 women with breast cancer, 38 were found to have asbestos in their lungs.

The second study suggests that asbestos fibers may have pierced the lungs and passed through the muscles covering the chest wall, eventually reaching the breast tissue. While there is not enough evidence to support the implication, there is a potential link between breast cancer and asbestos exposure.


Wagner, J. "Mortality from all cancers of asbestos factory workers in east London 1933-80." Pub Med n. pag. Web. 11 Apr 2011. Retrieved by Pub Med.

Cancer Overview

There are more than 100 diseases that fall under the broad umbrella of “cancer.” The uniting feature of these diseases is abnormal cell division – cancerous cells are those that grow out of control. Though cell division is an important bodily process that allows for growth and repairing injuries, when the DNA safeguards that control division rates fail, cancer develops. These cancerous cells often invade other, healthy tissues, something normal cells cannot do.

Damage to a cell’s DNA may cause it to replicate instead of die when it is no longer needed, creating more cells with damaged DNA. A variety of factors can cause this damage, from genetic abnormalities to environmental causes like smoking or asbestos exposure. However, the cause is not always known. If cancerous cells spread to other parts of the body through blood or lymph vessels, the cancer is said to have metastasized. This is often a sign that the cancer is in its later stages and makes the disease more difficult to treat.

Though in common speech, “tumor” is sometimes used as interchangeable with “cancer,” these words refer to two different things; not all cancers cause tumors, and not all tumors are cancerous. Leukemia, for example, causes cancer cells to develop in the blood and blood-forming organs like bone marrow, but does not form tumors. Benign tumors are noncancerous and cannot invade other tissues or metastasize. However, a benign tumor can cause health problems if it continues to grow and presses into other organs, disrupting their function.

Cancers can be divided into broad categories based on the locations where they originate. Carcinomas are cancers that begin in the skin or lining of the internal organs, whereas sarcomas are those that start in bone, cartilage, fat, muscle, blood, vessels, or other connective tissue. Leukemia, as noted above, begins in blood-forming tissues, and lymphoma and myeloma are cancers of immune system tissues and organs. Finally, central nervous system cancers are those that develop in the brain or spinal cord.

Unfortunately, cancer has become an extremely common phenomenon. The American Cancer Society projects that one-third of all women and half of all men in the United States will develop cancer at some point during their lifetimes. According to the National Cancer Institute, over 1.5 million new cases of cancer, not including melanoma, were reported in 2010, and 569,490 people died of cancer. Risk factors vary from region to region as well as person to person. Factors known to increase risk of developing cancer include smoking, heavy drinking, exposure to ultraviolet rays and sunlight, and poor diet.

Asbestosis Symptoms

Like mesothelioma, another serious disease caused by asbestos exposure, asbestosis has a long latency period, meaning that symptoms do not appear for a long period of time, even after exposure has ceased. Once asbestos fibers have been introduced into the body, particularly into the lungs, they are nearly impossible to remove and cause severe health problems over time. In the case of asbestosis, the latency period may be 20 years or more.

The primary symptoms of asbestosis are lung-related. Since accumulations of asbestos fibers in the lungs causes scar tissue to build up, decreased lung function is a key sign. Gradually increasing shortness of breath, dry cough, sporadic chest pain, and tightness in the chest are all pulmonary symptoms of asbestosis. These symptoms will get progressively worse if the disease is left untreated – at first, shortness of breath may only be a problem when the patient is exercising, but eventually it will affect the patient even if he or she is resting.

However, symptoms may not be limited to the lungs – clubbing, a thickening of the tissue under the fingernails that forces the nail to form a convex shape and the tips of the fingers to bulge, may also be an indicator of asbestosis. Clubbing occurs in patients with disorders that prevent oxygen from properly circulating throughout the body, and the lung scarring that is characteristic of asbestosis is such a disorder.

While there is no cure for asbestosis since the damage to the lungs cannot be reversed, there are treatments to alleviate the symptoms. Draining of the fluid around the lungs or wearing an oxygen mask may temporarily relieve shortness of breath. Some patients are helped by the use of inhaled medications usually prescribed for asthma. In severe cases of lung scarring, the patient may need a lung transplantation.

In some cases, patients with asbestosis may also develop malignant mesothelioma, a rare and aggressive cancer of the lining of the chest or abdomen. While the symptoms of both diseases are similar, the life expectancy for mesothelioma patients is much lower, since the cancer progresses very quickly once it develops.

Asbestosis Diagnosis

The first step in making a diagnosis of asbestosis, a disease caused by scar tissue in the lungs, is the medical and occupational history a doctor takes when first consulting with a patient. Since asbestosis is caused exclusively by inhalation of asbestos fibers, the doctor will want to know whether there is a chance that the patient’s current symptoms may be related to past asbestos exposure. Asbestosis can have a latency period of between 10 and 20 years, so the patient will likely need to give an occupational history that covers several decades.

If the doctor suspects asbestosis, there are several tests that can determine the nature of the lung problem. Pulmonary function testing measures airflow and volume of air in the lungs, and requires the patient to perform various activities that may include forced or rapid breathing or breathing in a gas such as nitrogen or helium. Measurements of amount and rate of breath are made using an instrument called a spirometer, so this process is also called spirometry.

Spirometry can alert the doctor if lung function is compromised, but it cannot always pinpoint the specific problem. Noninvasive imaging tests are often used to give the doctor a better look at the patient’s lungs. Simple chest X-rays are useful for this purpose, as lung scarring will appear as patches of excessive whiteness. Computed tomography (CT) scans also make use of X-rays to create an image of the inside of the body, but provide a more detailed image than a standard X-ray machine and are especially useful in diagnosing asbestosis in its earlier stages. Depending on the available equipment, the doctor may order a high resolution CT (HRCT) scan.

Finally, a bronchoscopy may be necessary to get a better picture of the patient’s airways and collect samples of lung or other tissue for analysis. A bronchoscope is a long, thin tube that is inserted into the patient’s nose or mouth and down the windpipe. Flexible bronchoscopes may be used with patients who are awake, but larger, rigid bronchoscopes require the patient to be under general anesthesia. The doctor may take a tissue sample either by injecting saline through the tube and collecting it again or by passing special brushes or needles through the tube to biopsy small pieces of the lung tissue.

Asbestosis Causes

Asbestosis is a chronic inflammation of the lungs caused exclusively by inhaling asbestos fibers. Though it is not a type of cancer, it is a serious health condition and can be fatal. Though asbestos was known to be a cause of serious lung problems even earlier, a pathologist named Dr. Cooke first used the term “asbestosis” to describe a 1927 case of a 33-year old man who had worked in a carding room where asbestos fibers were processed. As the name suggests, there were no doubts of the connection between the disease and its origins with asbestos.

Asbestosis most often results from occupational exposure – coming into contact with asbestos in the course of one’s job. Anywhere that asbestos was mined or processed, or asbestos-containing materials were sawed, cut, or otherwise damaged posed a danger of airborne asbestos fibers. According to the CDC, construction workers accounted for nearly one in four patients who died of asbestosis. However, insulation workers and boilermakers had the highest mortality rate of any profession. Once inhaled into the lungs, asbestos fibers are unable to be removed by the immune system and often irritate the surrounding tissue, causing the fibrosis that is characteristic of asbestosis.

While primary exposure is more likely to cause asbestosis, secondary exposure also posed a risk to family members and friends of those who worked with asbestos. Fibers could stick on clothes and hair and be transported home if the asbestos worker did not change clothes or properly wash before leaving work. Since most workers were unaware of the dangers of the material, they did not take these precautions, and asbestosis has been known to develop in those who washed the clothes of asbestos workers.

Smoking alone will not cause asbestosis, but several studies have suggested that a person who smokes and is exposed to asbestos has a greater chance of developing lung problems, including asbestosis and lung cancer, than a nonsmoker who is exposed. Smokers and former smokers with asbestosis may also have a higher mortality rate than nonsmokers with asbestosis.


Asbestosis is a breathing disorder that is developed from inhaling asbestos fibers. After several years, the inhalation of these fibers can lead to scarring in the lungs and shortness of breath, among other symptoms. For many years, asbestos fibers were used in flooring materials and insulation. As a result, many people working in the construction industry contracted asbestosis after coming into contact with the asbestos fibers. Beginning in the 1970s, however, the government began to regulate the use of asbestos so fewer people would contract the disease. Today, the use of asbestos is highly regulated by the government to limit exposure to the substance.

Symptoms of Asbestosis

For those exposed to asbestos, the symptoms may not become visible for up to 50 years. However, symptoms do increase gradually over time, and include shortness of breath, lack of desire to exercise, clubbing of fingers, coughing and chest pain. If you experience any of these symptoms for a prolonged period of time, see a doctor immediately. There are several treatment options that help reduce the severity of these symptoms.

Exposure to Asbestos

While asbestos occurs naturally in the environment, very little exposure to asbestos will not cause serious harm to the lungs. Those who are most likely to become sick from the substance are those who have prolonged exposure to asbestos – such as construction workers, miners, or those who spend a lot of time in buildings that still contain asbestos. Although the government regulates the use of asbestos inconstruction, there are still a few buildings that remain from the era when asbestos was commonly utilized in construction. Many of these buildings are older, pre-1970s, and have not had asbestos removed from the site since. Removing asbestos from a building can often be very costly, and sometimes companies or individuals do not have the means to have it removed. However, if you do own a home or business that still contains asbestos, seek the help of a professional before having it removed. This will ensure that the asbestos is removed safely and entirely from the premises.

Risk Factors

The severity of complications that arise from asbestosis typically correlate with the length of time of exposure to asbestos. The longer the exposure period, the harsher the complications. Sometimes, these complications can be disabling or even fatal, whereas others are hardly noticeable. Smoking increases the risk of contracting cancer in individuals who were exposed to asbestos, since the lungs are already damaged. Other complications include high blood pressure in the lungs (pulmonary hypertension) and heart problems related to this. Asbestosis is primarily a disease that attacks the lung tissues, so these are the most at-risk organs in the body after contracting the disease. Symptoms related to asbestosis will generally not increase in severity after being removed from exposure.

Illnesses With Similar Symptoms

One of the reasons that mesothelioma can be difficult to diagnose is that itssymptoms, particularly early on, can be confused with the symptoms of several other common illnesses. Quite frequently, patients who are eventually diagnosedwith mesothelioma first tend to think they have a cold, the flu, bronchitis, or pneumonia. Doctors will often prescribe antibiotics or other types of treatment that do not work for mesothelioma. This delayed treatment allows the disease to spread.

The Common Cold

Cold symptoms can begin slowly with the onset of a sore throat, then nasal drainage that is clear and watery. This is followed by sneezing, fatigue and a slight fever, normally 100 F or less. Post-nasal drip can cause the coughing and sore throat to worsen.

The cough is a fairly common symptom of a cold. While usually not severe, the cough can last as long as two weeks and will be worse in people who have asthma or other lung-related problems. Colds can sometimes be accompanied by bacterial infections, the signs of which are cough that is worse and coughing up dark mucus. It can even cause some pain in the lower section of the lungs. A cold will normally last only from 4 to 10 days.


The flu is often confused with a cold because many of those symptoms are similar. The flu comes on more suddenly than a cold and the symptoms that accompany the flu will usually make you feel worse than a cold. Some of those symptoms are:

  • Fever typically over 100 degrees. The fever is usually ongoing, although it can come and go. If the fever is high, the other symptoms are often more severe.
  • Sweats and chills
  • Headache
  • Dry cough, sore throat, and runny nose. These symptoms may be more noticeable after the fever stops.
  • Muscle pain and body aches in the back, arms, and/or legs
  • Fatigue and an overall feeling of weakness and a loss of appetite
  • Nasal congestion

The symptoms of the flu normally don’t include anything stomach or intestinal related.


Bronchitis symptoms usually start after some type of upper respiratory infection like a cold or the flu, about 3 or 4 days later. The symptoms include:

  • Cough. This is the primary symptom of acute bronchitis. It will start out as a dry cough without mucus and eventually will begin to produce mucus.
  • Low-grade fever under 101 degrees.
  • Feeling fatigued
  • Pain, tightness, or burning in the chest that is worse when breathing and coughing
  • Wheezing sounds when breathing, particularly during any type of exertion
  • Hoarseness

A normal case of acute bronchitis lasts from 2 to 3 weeks, but often they can last a month or more. Chronic bronchitis results from long periods of inflammation that scars the bronchial tubes. The cough that accompanies chronic bronchitis is worse in the morning and when the weather is damp. People with chronic bronchitis are subject to frequent colds and flu.


Pneumonia that is caused by bacteria normally starts after a cold or influenza. The symptoms are:

  • A cough that produces mucus
  • Fever, but in older adults this is not as common is it is in children and young adults
  • Chills and shaking
  • Shortness of breath and shallow breathing
  • Pain in the chest wall that is worse when coughing and breathing
  • Rapid heartbeat
  • Fatigue
  • Nausea and vomiting

Non-bacterial pneumonia symptoms include the cough with mucus, shortness of breath, and fever. This type of pneumonia comes on more slowly and is usually not as severe as bacterial pneumonia.

Early Symptoms of Mesothelioma

Mesothelioma is a rare form of cancer that many people are not even aware they may have. The symptoms are very subtle in the beginning and may go unnoticed. Some people experience no symptoms at all. This can lead to mesothelioma being left undiagnosed or misdiagnosed for several years. It is imperative that a person seek out medical attention at the first signs of mesothelioma. If the mesothelioma is left undiagnosed and untreated, the cancer can spread throughout the body.

Latency Period

This particular type of cancer can lay dormant for up to 50 years after exposure to asbestos. If a person knows they have been exposed to asbestos it is important to relay that information to a doctor. The doctor will most likely schedule regular mesothelioma screenings. Asbestos exposure is directly related to the onset of mesothelioma. Even a brief exposure to asbestos can result in mesothelioma. A doctor will monitor the lungs closely to watch for any signs of the disease. A person has a higher rate of survival if the cancer is caught in its earliest stages. The highest rates of survival are best if caught before symptoms even begin to develop.

Basic Symptoms of Mesothelioma

Early symptoms of mesothelioma are generally shortness of breath and a heavy feeling in the chest area. Ninety percent of all patients will notice these two symptoms. However, because the symptoms do not seem serious many choose not to seek out medical care. The shortness of breath or heaviness is caused by a fluid buildup in the lungs. These two symptoms should be taken seriously, especially if a person has a history of asbestos exposure.

Types of Mesothelioma

The lung or chest area is the most common place for mesothelioma to occur. This type is referred to as pleural mesothelioma. The abdominal cavity is also prone to develop mesothelioma. Any tumor found in that area is referred to as peritoneal mesothelioma. The symptoms associated with the different types of mesothelioma are similar and may overlap each other. Pericardial mesothelioma involves the lining around the heart.

Additional Symptoms of Mesothelioma

Some symptoms common with pleural mesothelioma include back, chest or side pain, difficulty swallowing, cough, fatigue and weight loss. Peritoneal mesothelioma is often accompanied by abdominal pain, nausea and vomiting, back pain, anemia and bowel obstruction. Both types of mesothelioma may leave a person feeling very weak. It is extremely important a person visits their doctor if they notice any of these symptoms. The longer mesothelioma is allowed to go untreated the less favorablethe outcome.

Similar Diseases and Illnesses

Any of the earlier mentioned symptoms can also indicate asbestosis, which is abenign result of asbestos exposure. However, an asbestosis diagnosis does not mean a person will not develop mesothelioma later. It is crucial a person has their symptoms evaluated to determine whether or not they are benign or malignant. Asbestosis will need to be closely monitored as well just in case it becomes malignant and can pose serious health concerns.

Types of Mesothelioma

Mesothelioma is a rare form of cancer that originates from the mesothelium, a protective lining that sheaths the internal organs of the body. The different types of mesothelioma are terms used to differentiate where in the body the cancer exists.

Pleural Mesothelioma

Pleural mesothelioma typically develops within the chest cavity and lungs. The most common type of malignant mesothelioma, it often spreads to numerous other organs and lymph nodes in the body. The difficulty in diagnosing and detecting pleural mesothelioma makes treatment tougher. Symptoms such as chest pains, weight loss and fever are far too common to be noticed as a precursor for cancer. More severe symptoms such as breathing difficulties and fluid buildup may not appear until after the disease has progressed. The survival rate for sufferers of pleural mesothelioma is tragically low. Only 8% live beyond three-to-five years after the onset of initial symptoms, and the average life expectancy is closer to 12 months.

Cancer cell

Pericardial Mesothelioma

The least common form of malignant mesothelioma, pericardial mesothelioma affects the heart. This rare form of cancer is found in the sac that surrounds the heart, also known as the pericardium. The cancer prevents the heart from transporting oxygen to the body efficiently, and as a result the patient's body deteriorates from an elevated heart rate. Heart attack, nausea, chest pain, and shortness of breath are signs of pericardial mesothelioma.

Peritoneal Mesothelioma

Peritoneal mesothelioma develops in the abdominal area and can quickly spread to the liver, bowel, or spleen. Fluid buildup or severe stomach pain can be a sign of peritoneal mesothelioma, in addition to vomiting, bowel trouble, fever, and tumescent feet. Patients generally only survive 10 months from the day of the initial symptoms.

Malignant Versus Benign

The aforementioned types of mesothelioma are malignant forms, and are thusly the most dangerous. Malignant mesothelioma is often the product of asbestosinhalation from

individuals who have worked or resided in areas not up to current health and safety standards. Since the disease has a high latency period, often times it is not diagnosed until it has progressed far beyond any rectifiable measure.

As the name suggests, benign mesothelioma is a form of non-malignant mesothelioma that is easily treatable. While benign tumors can at times be cancerous, unlike malignant mesothelioma, the tumors do not spread, making it easier to isolate and remove.

Mesothelioma in Uncommon Locations

In addition to pleural, pericardial, peritoneal, and benign mesothelioma, the cancer can also strike the ovaries and testes. These tumors are born in the membrane lining the organs. The total number of cases of testicular or ovarian mesothelioma are less than a hundred, and symptoms are rarely identified. As a result, the prognosis for this type of mesothelioma are not promising. The effects of the disease are such that any individual who has had prolonged asbestos exposure orinitial symptoms of mesothelioma should consult a doctor.

Senin, 11 April 2011

Understanding Cancer

The word cancer refers to changes in the body's cells that allow these cells to grow out of control. These cells often grow very fast, crowding out normal cells in the area around the cancer. Cancer cells also have the ability to spread, ormetastasize, to other organs in the body, causing additional damage in areas of the body not connected with the original cancer site.

Cancer can occur in almost any cell. It begins when the cell's DNA, or genetic information, becomes damaged. DNA controls all cell functions, including when to divide (reproduce) and when to die. When DNA is damaged, some cells become unstable, dividing more often than normal cells or failing to die when they should. Most of the time, the body's immune system finds these damaged cells and destroys them. However, if this normal process does not happen, atumor can begin.

A tumor is a mass, or collection, of abnormal cells. Tumors can be eitherbenign or malignant.
• Benign tumors (noncancerous) can grow and expand in size, but they do not invade surrounding tissue or travel to other areas of the body.

• Malignant tumors (cancerous) are made up of cells that are very different from normal cells. These cancer cells can, and often do, invade nearby tissues. They also can travel away from the original (primary) site to other parts of the body, causing tumors in other organs (distant sites) in a process called metastasis.

Types of Cancer

A solid tumor is a localized mass of abnormal cells. Solid tumors are divided into broad categories based on the type of tissue where the cancer first occurred; carcinomas, sarcomas, and lymphomas are examples of solidtumors. Table 1-1 shows different types of cancer and where they originate.1 In addition, cancers are defined by the type of cell or organ where they came from. For example, a cancer beginning in the colon is called colon cancer or coloncarcinoma. Cancers originating in certain cells found in the skin are called basal cell carcinomas

Not all cancers, however, form solid tumors. Cancers of the blood or bone marrow (hematologic malignancies), are often referred to a "liquid tumors" because they do not form a defined mass of abnormal cells like solid tumors do. Examples of liquid tumors include leukemia and multiple myeloma.

Table 1-1: Types of Cancer1
Type of CancerCell Type of Origin
CarcinomaSkin or tissues that line or cover internal organs
SarcomaBone, cartilage, fat muscle, blood vessels, or other connective or supportive tissue
Central nervous system cancerTissues of the brain and spinal cord
LymphomaCells of the immune system
Leukemia andmyelomaBlood forming tissue, such as the bone marrow

Causes of Cancer

Although every patient and family member wants to know what may have caused their cancer, the reason a particular person developed cancer is, in many cases, not well understood.

Cancer occurs because normal cells become abnormal due to harmful mutations in one or more genes.4 While the reasons that cells become abnormal are not completely understood, certain known risk factors increase the chance that genes will become mutated. Still, not all people who have risk factors will develop cancer—in fact, most people with a particular risk factor do not develop cancer. On the other hand, some people who have no known risk factors will get cancer. Separate risk factors may combine over time to cause normal cells to become abnormal.

Known Risk Factors for Cancer

Below are some known risk factors for cancer.
  • • An individual person's risk of cancer increases with advancing age, even though many cancers can develop at any age.
  • • Some gene mutations that increase the risk of cancer can be passed from parent to child.
  • • Menopausal hormone therapy with estrogen and/or progestin can increase the risk of breast cancer.
  • • Infection with some viruses and bacteria can increase the risk of cancer. Even so, cancer is not contagious. Examples of viruses and bacteria that can increase the risk of cancer include:
  • o Infection with certain types of the human papillomavirus (HPV) is a major cause of cervical cancer.
  • o Infection with the Epstein-Barr virus is associated with an increased risk of lymphoma.
  • o The Helicobacter pylori bacterium can cause some kinds of stomach cancer.
  • • Exposure to ultraviolet radiation from the sun, sunlamps, and tanning booths can cause skin damage that increases the risk of skin cancer.
  • • Exposure to ionizing radiation, such as radon gas, x-rays, and radioactive fallout, can increase the risk of many kinds of cancer. The risk of cancer from low-dose x-rays is very small.
  • • Exposure to chemicals such as benzene, metals such as nickel, or substances such as asbestos has been shown to increase the risk of cancer.
  • • Poor diet, lack of physical activity, or being overweight may increase the risk of developing many kinds of cancer.
  • • Having more than two alcoholic drinks per day over many years may increase the risk of developing cancer of the mouth, throat, esophagus, larynx, liver, or breast.
  • • Tobacco smoking increases the risk of developing cancer in the lungs, throat, voice box, mouth, esophagus, bladder, kidney, stomach, pancreas, or cervix. People who smoke are also more likely to develop a cancer of the blood cells called acute myeloid leukemia. Use of snuff or chewing tobacco increases the risk of developing cancer of the mouth.

Treating Cancer

Because cancer is a complicated disease that takes many different forms, it is treated in many different ways. Treatment is tailored to the specific needs of the patient.

Cancer treatments vary depending upon four main factors:
• Type of cancer
• Stage of cancer
• Your overall condition
• Goal of treatment

Your doctor will determine the stage and grade of your cancer. Learn aboutstaging and grading of cancer.

The goals of cancer treatment also vary:
• Cure
• Prolong life
• Reduce unwanted symptoms or effects of the cancer

Your doctor may recommend one or more treatments, also referred to asmodalities, to achieve your goals. Increasingly, it is common to use several treatments at the same time or in sequence in order to prevent both local recurrence and recurrence throughout the body. This is referred to as a multi-modality treatment. Modalities include chemotherapy, surgery, radiation therapy, biological therapy, and hormone therapy. Chemotherapy is one of the best ways to help you achieve your treatment goals. Find out about treating cancer with chemotherapy.

Your doctor may also discuss combining your chemotherapy with other treatments. Learn about treating cancer in other ways.

Reasons to Be Optimistic

As you move beyond the initial shock of learning that you have cancer to begin the journey of surviving cancer, you have many good reasons to be optimistic. Science and medicine have made—and continue to make—tremendous progress in treating cancer and in making treatments more manageable, both physically and emotionally. Chemotherapy is one of the most significant advances in the history of medicine. For millions of people, it helps treat their cancer effectively and helps them enjoy full, productive lives. However, chemotherapy is not without side effects and risks. Learn about managingchemotherapy side effects

No one would call having cancer or undergoing chemotherapy a normal experience, but by proactively managing your treatment with your doctor, including potential side effects, you can help ensure that your life stays as close to normal as possible.

Don't forget: You are not alone. Fighting cancer is a team effort that involves family, friends, and your healthcare team.