Tuesday 24 March 2009

Mesothelioma

Mesothelioma disease is a form of severe cancer that is virtually always caused by a previous exposure to asbestos materials. In mesothelioma disease, malignant cells develop in the mesothelium which is a protective lining that is a covering of most of the body's internal organs.

Its most common location is the pleura which is the outer lining of the lungs but it also occurs in the peritoneum whic is the lining of the abdominal cavity or the pericardium which is a sac that surrounds the heart.


Mesothelioma: is classified as a tumor of the mesothelium which can be either benign (localized) or malignant (diffusely spread) and that is usually caused by the ingestion of asbestos product particles.

Mesothelium is the thin layer of mesodermal epithelial cells that forms the pleura, peritoneum and pericardium.

Mesothelioma is a very unusual but no longer very seldom cancer that is usually very difficult to diagnose, treat and responds very poorly to typical therapy. Mesothelioma is a known cancer in which cancerous and/or malignant cells begin appear around the heart, chest or abdominal region of the human body. It is believed that the main cause is usually from exposure to asbestos. It takes about 30 to 40 years after asbestos exposure for mesothelioma cancer symptoms to start appearing.

Most people working for asbestos manufacturing firms have been exposed to the asbestos substance which then lead to Mesothelioma Cancer. Once the mesothelioma symptoms are then detected the patient usually has a maximum life span of 18 months - give or take. This is a very heart-breaking fact. So who are the people or persons responsible for this mesothelioma disease?

Mesothelioma Disease
Mesothelioma Disease

The most severest form of mesothelioma cancer which is usually caused by exposure to asbestos is called malignant mesothelioma. The ones who have worked for years in the industries where asbestos products were used are most often diagnosed with this terrible and fatal form of cancer. Mesothelioma is not so easily detectable and is usually very difficult and hard to diagnose. The early symptoms of mesothelioma disease are frequently dismissed by suffering patients as common everday ailments until the effects of mesothelioma disease increase in severity. By then the mesothelioma disease has progressed to a stage where a cure is virtually not possible at all.

About three/fourths of mesothelioma disease symptoms start in the chest area cavity and are usually known as pleural mesotheliomas. Another 10% to 20% begin in the abdomen or stomach area and are called peritoneal mesotheliomas. Pericardial mesotheliomas, are those starting in the cavity around the heart and are very, very rare cases. The outter covering layer of the testicles is also actually an outpouching of peritoneum that goes into the scrotum area. We have found that mesotheliomas that can affect that covering of the testicles are usually quite rare.

Mesothelioma Disease in the lungs
Mesothelioma Disease in the lungs

Although the mesothelioma disease is much more commonly seen in people how are 60 years old and are usually men it has been commonly been diagnosed in women as well and in early childhood. The common cause of mesothelioma disease is not so well understood as of yet in these latter two groups but there is some new evidence of the possible asbestos exposure in many of these cases as well.

Pleural Mesothelioma Symptoms

One of the most common symptoms known for pleural mesothelioma patients is chronic chest pain but the chest pain is often not associated directly with the lung pleura. It often appears in the shoulder or the upper abdomen area. Other known symptoms are shortness of breath which is called dyspnea and is also a symptom of mesothelioma disease.

Chronic coughing, rapid weight loss and anorexia are present in some mesothelioma disease patients but are less common. The rapid growth of the pleural mesothelioma cancer tumors tend to enlarge the pleural space which causes it to be filled with fluid which leads to painful discomfort or pain associated with first detection of the mesothelioma disease.

There was a study involving over 167 patients with proven pleural mesothelioma disease and they found that the median survival rate of mesothelioma disease patients following diagnosis was numbered at 242 days. The survival rate for mesothelioma disease patients was also affected by the type of mesothelioma disease cancer cells and patients with biphasic cell types tend to have the shortest life expectancy known.

Pleural Mesothelioma

Pleural mesothelioma is a disease that affects the lining of the lungs, or the lung pleura. Sometimes doctors refer to this disease as mesothelioma of the pleura.

It is a common notion and misconception that mesothelioma disease is a kind of primary lung cancer but it's is not at all. Mesothelioma disease is a cancer of the serous membranes.

These membranes enclose many of the internal organs spread all throughout the midsection of the human body including but not limited to the lining of the lungs.

One of the most common types of mesothelioma disease is known as pleural mesothelioma which generally affects the serous membranes of the human lungs.

What is known as Pleural mesothelioma cancer usually represents around 75 percent of all mesothelioma disease cases. mesothelioma disease is caused by the inhalation of asbestos fibers which eventually settle themselves and stay in the lungs forever. Tiny asbestos fibers eventually become permanently imbedded in the inner lining of the lung (the pleura) and over time they can cause what's known as chronic inflammation and eventually will lead to growth of severe cancerous tumors and in some cases asbestosis.

Pleural mesothelioma cancer will normally appear as a multiple tumor with masses that affect the parietal surface of the lung which is inside and closer to the lung and the visceral surface which is outside and further from the lung of the pleura. Usually the parietal surface has a much more greater involvement than the visceral.

There is usually a slightly higher incidence of mesothelioma disease in the right side lung apparently due to the overwhelming fact that the right lung is generally larger and has a far greater amount of pleural surface area within it.

The very large growths in the pleura are normally noted in mesothelioma disease patients upon diagnosis. As mesothelioma disease progresses these growths tend to lead to a complete obliteration of the human lung cavity. These tumors then spread from the lung pleura to other organs including the heart and the abdomen. mesothelioma disease usually also invades the lymph nodes and the circulatory system.

Mesothelioma

Mesothelioma is a form of cancer that is almost always caused by previous exposure to asbestos. In this disease, malignant cells develop in the mesothelium, a protective lining that covers most of the body's internal organs. Its most common site is the pleura (outer lining of the lungs and internal chest wall), but it may also occur in the peritoneum (the lining of the abdominal cavity), the heart, the pericardium (a sac that surrounds the heart) or tunica vaginalis.

Most people who develop mesothelioma have worked on jobs where they inhaled asbestos particles, or they have been exposed to asbestos dust and fiber in other ways. Washing the clothes of a family member who worked with asbestos can also put a person at risk for developing mesothelioma. Unlike lung cancer, there is no association between mesothelioma and smoking, but smoking greatly increases risk of other asbestos induced cancer. Compensation via asbestos funds or lawsuits is an important issue in mesothelioma.

The symptoms of mesothelioma include shortness of breath due to pleural effusion (fluid between the lung and the chest wall) or chest wall pain, and general symptoms such as weight loss. The diagnosis may be suspected with chest X-ray and CT scan, and is confirmed with a biopsy (tissue sample) and microscopic examination. A thoracoscopy (inserting a tube with a camera into the chest) can be used to take biopsies. It allows the introduction of substances such as talc to obliterate the pleural space (called pleurodesis), which prevents more fluid from accumulating and pressing on the lung. Despite treatment with chemotherapy, radiation therapy or sometimes surgery, the disease carries a poor prognosis. Research about screening tests for the early detection of mesothelioma is ongoing.

http://www.mesothelioma108.com/img/Pleural-Mesothelioma.gif

Symptoms of mesothelioma may not appear until 20 to 50 years after exposure to asbestos. Shortness of breath, cough, and pain in the chest due to an accumulation of fluid in the pleural space are often symptoms of pleural mesothelioma.

Symptoms of peritoneal mesothelioma include weight loss and cachexia, abdominal swelling and pain due to ascites (a buildup of fluid in the abdominal cavity). Other symptoms of peritoneal mesothelioma may include bowel obstruction, blood clotting abnormalities, anemia, and fever. If the cancer has spread beyond the mesothelium to other parts of the body, symptoms may include pain, trouble swallowing, or swelling of the neck or face.

These symptoms may be caused by mesothelioma or by other, less serious conditions.

Mesothelioma that affects the pleura can cause these signs and symptoms:

  • chest wall pain
  • pleural effusion, or fluid surrounding the lung
  • shortness of breath
  • fatigue or anemia
  • wheezing, hoarseness, or cough
  • blood in the sputum (fluid) coughed up (hemoptysis)

In severe cases, the person may have many tumor masses. The individual may develop a pneumothorax, or collapse of the lung. The disease may metastasize, or spread, to other parts of the body.

Tumors that affect the abdominal cavity often do not cause symptoms until they are at a late stage. Symptoms include:

  • abdominal pain
  • ascites, or an abnormal buildup of fluid in the abdomen
  • a mass in the abdomen
  • problems with bowel function
  • weight loss

In severe cases of the disease, the following signs and symptoms may be present:

  • blood clots in the veins, which may cause thrombophlebitis
  • disseminated intravascular coagulation, a disorder causing severe bleeding in many body organs
  • jaundice, or yellowing of the eyes and skin
  • low blood sugar level
  • pleural effusion
  • pulmonary emboli, or blood clots in the arteries of the lungs
  • severe ascites

A mesothelioma does not usually spread to the bone, brain, or adrenal glands. Pleural tumors are usually found only on one side of the lungs.

Peritoneal Mesothelioma Cancer

Peritoneal mesothelioma cancer is found in 10% to 20% of the mesothelioma patients. The only known cause of mesothelioma is exposure to asbestos. For pleural mesothelioma (cancer of the lung lining), the disease process is fairly well understood. It is caused by the inhalation of asbestos fibers that settle in the lungs. These asbestos fibers become inserted in the lung lining (or pleura). Asbestos fibers are very durable and cannot be eliminated through the body's processes. Over time, they cause chronic inflammation that eventually leads to growth of cancerous tumors or in some cases asbestosis.

For peritoneal mesothelioma, it is not clearly understood how the asbestos fibers become lodged in the abdomen's peritoneum lining. It is possible that asbestos fibers, after being broken into smaller pieces in the lungs, are carried from the lungs into the blood stream, and lodge from the blood stream in the abdomen lining.

A more probable cause is that asbestos fibers were ingested with food or drink. Most asbestos mining or processing facilities had constant clouds of asbestos fibers. These fibers could have settled on the food of the workers. Also, it is well established that many of the workers' clothing became infiltrated with asbestos dust. This dust could have contaminated the kitchens of the workers as they arrived home with the dirty clothing. Once lodged in the peritoneum, the chronic inflammation process leading to cancerous growths is similar to that occurring in pleural mesothelioma.

Mesothelioma of the Testicles

A rare form of peritoneal mesothelioma affects the male testicles. The covering layer of the scrotum is actually an outpouching of the peritoneum. It is thought that the asbestos fibers migrate from the stomach area to become lodged in the portion of the peritoneum surrounding the scrotum.

Peritoneal Mesothelioma Symptoms

Once the cancerous tumors start to grow in the peritoneum, fluid begins to rapidly accumulate in the abdominal area. This fluid causes swelling and discomfort and leads to the first common symptoms of peritoneal mesothelioma: upper abdominal pain. Less common symptoms include cough and shortness of breath. Many patients have symptoms four to six months before diagnosis.

Peritoneal mesothelioma patients can exhibit all three kinds of mesothelioma cancer cells: epithelioid mesothelioma, sarcomatoid mesothelioma and biphasic mesothelioma. The type of cancer cells can affect the prognosis. It is thought that patients with biphasic mesothelioma cancer cells have a shorter life expectancy, than that for epithelioid or sarcomatoid.

Peritoneal mesothelioma

Malignant peritoneal mesotheliomaAbdominal cavity showing the location of the peritoneum; peritoneal mesothelioma. is an extremely rare condition. Only 100 to 500 cases are diagnosed in the US each year, making up less than 30% of all mesothelioma cases.

Peritoneal mesothelioma is a cancer affecting the abdominal lining, or peritoneum (paira-tin-e-um), which is why is is sometimes referred to as abdominal mesothelioma. This membrane supports and covers the organs of the abdomen.

The peritoneum is made of two parts, the visceral and parietal peritoneum. The visceral peritoneum covers the internal organs and makes up most of the outer layer of the intestinal tract. Covering the abdominal cavity is the parietal peritoneum.

Cells in these linings secrete a fluid which allows organs to move against one another. For instance, as the intestines move food through the body. The cells of the mesothelium are designed to create fluid, but the cancer causes them to overproduce, creating a build up of excess fluid in the abdominal cavity.

Because pleural mesothelioma is more common and often spreads to the peritoneal cavity, it is important to determine if pleural mesothelioma is the primary cancer.

Peritoneal mesothelioma is a disease that affects the lining of the abdomen, or peritoneum. Sometimes doctors refer to this disease as mesothelioma of the peritoneum. It is a common misconception that mesothelioma is a type of primary lung cancer; it is not. Mesothelioma is a cancer of the serous membranes. These membranes enclose a number of organs throughout the midsection of the body, including the abdomen. The most common type of mesothelioma is pleural mesothelioma, which affects the serous membranes of the lungs.


Peritoneal mesothelioma is a disease that affects the lining of the abdomen, or peritoneum. Sometimes doctors refer to this disease as mesothelioma of the peritoneum. It is a common misconception that mesothelioma is a type of primary lung cancer; it is not. Mesothelioma is a cancer of the serous membranes. These membranes enclose a number of organs throughout the midsection of the body, including the abdomen. The most common type of mesothelioma is pleural mesothelioma, which affects the serous membranes of the lungs.

The second most common form of mesothelioma cancer is peritoneal mesothelioma. Peritoneal mesothelioma can spread to the lungs and when this occurs, it is considered secondary lung cancer. Mesothelioma is also sometimes referred to as an asbestos lung cancer. Technically, this is also incorrect, since it does not originate in the lungs. Asbestosis is a type of asbestos lung disease that does originate in the lungs and is often confused with mesothelioma.

mesothelioma survival rate

The mesothelioma survival rate indicates the percentage of people with a certain type and stage of mesothelioma who survive the disease for a specific period of time after their diagnosis. In most cases, statistics refer to the 5-year mesothelioma survival rate. The 5-year mesothelioma survival rate is the percentage of people who are alive 5 years after a mesothelioma diagnosis, whether they have few or no signs or symptoms of mesothelioma, are free of disease, or are receiving treatment for mesothelioma.
The mesothelioma survival rate is based on large groups of people, and it cannot be used to predict what will happen to a particular patient. No two patients are exactly alike, and mesothelioma treatment and responses to treatment vary greatly.

Overall Mesothelioma Survival Rate

Survival rates can be calculated by different methods for different purposes. The survival rates presented here are based on the relative survival rate. The relative survival rate measures the survival of mesothelioma patients in comparison to the general population to estimate the effect of cancer. The overall 5-year relative mesothelioma survival rate for 1998-2002 was approximately 9 percent.
Below are the relative survival rates for each year following a mesothelioma diagnosis:
  • Year 1 mesothelioma survival rate: 39 percent
  • Year 2 survival rate: 20 percent
  • Year 3 survival rate: 11 percent
  • Year 4 survival rate: 10 percent
  • Year 5 survival rate: 9 percent.

Mesothelioma prognosis

he overall prognosis for individuals with mesothelioma is not very good. The disease has among the lowest five year survivability rates among different cancers and remains extraordinarily difficult to treat. While research is ongoing and our knowledge of the disease is definitely increasing faster than it ever has, doctors know an actual cure is still years away. However, large variabilities exist in many mesothelioma patients and there are people who have lived full lives after their diagnoses.

Mesothelioma Prognosis: Statistics

When mesothelioma is examined in purely statistical terms, the prognosis figures are discouraging. Pleural mesothelioma typically presents in an advanced stage of progression with a ten-to-fourteen month lifespan expectation from diagnosis. Peritoneal mesothelioma often presents with a slightly more optimistic lifespan expectation and patients surviving two to five years are not uncommon. However, after five years, statistics show survivability dropping to well below thirty percent.

Statistics, however, do not tell the whole story. There are a variety of factors in the development of a patient’s mesothelioma prognosis and subtle differences among these factors can have a dramatic impact on the course the disease will take. The statistical models used in mesothelioma often miss the extraordinary differences between a person’s stated prognosis/diagnosis and the way in which the disease actually impacts his or her life. While rare, it is not unknown for an individual to live for ten or sometimes even twenty years after a diagnosis of mesothelioma.

Mesothelioma Prognosis: Biology of the Disease

The most important disease-specific prognostic factors for patients with mesothelioma involve the form of mesothelioma as presented and the histological subtype of the presented disease. Of the two major forms of mesothelioma, pleural mesothelioma generally presents with a worse prognosis than peritoneal mesothelioma does. The physiological reasons for this difference are not completely understood, but a major factor is the histological aspect of the cancer. Pleural mesothelioma presents about fifty percent of the time with an epitheloid histologic subtype, twenty percent of the time with sarcomatoid subtype and the remaining thirty percent is the biphasic subtype, which is a combination of the previous two subtypes. Peritoneal mesothelioma presents in the vast majority of diagnoses with the epitheloid subtype. This is significant because epitheloid mesothelioma responds more favorably to treatment than sarcomatoid mesothelioma or biphasic mesothelioma does. Thus, with the majority of peritoneal cases featuring the most treatable histological subtype, one would expect for it to have a better overall prognosis. Conversely, with only half of pleural cases involving the most treatable subtype, one would also expect a generally worse prognosis.

Mesothelioma Prognosis: Patient Status

Along with the biological aspects of mesothelioma as presented, another set of important prognostic factors includes the stage of the disease at diagnosis, the health of the patient and his or her age. All three will have a major impact on life expectancy and the future course of the disease.

Stage of the Disease

The stage of disease at diagnosis is a crucial factor in the development of the patient’s prognosis. As with all forms of cancer, early detection is important, but this is especially true of mesothelioma. Because mesothelioma generally resists curative treatment, doctors can manage the disease more efficiently if they have caught it in its early stages. The diffuse nature of the disorder means advanced tumor progression will invade large areas of tissue, making treatment even more difficult. Mesothelioma presents with symptoms shared by a number of other diseases and often goes undiagnosed because of these similarities. An early diagnosis is absolutely crucial if one hopes to control the disease.

Performance Status

Another important prognostic factor is the overall health of the person, with the patient’s age an important sub-factor in this determination. Generally, the healthier a patient presents, the better he or she will respond to cancer treatments and the better chances he or she has of longer survival. When grading a patient’s health, doctors develop a figure known as a patient’s “performance status.” There are a number of competing scales used to gauge this, but the scale sponsored by the World Health Organization goes from 0 to 5, with 1 and 4 being the general limits of description.

Performance Status Measurements
Number Description
0 Asymptomatic
1 Symptomatic but completely ambulant
2 Symptomatic, <50%>
3 Symptomatic, >50% in bed, but not bedbound
4 Bedbound
5 Death

Performance status is revisited at multiple times during the course of treatment. It is initially developed after diagnosis and is then updated in response to the patient’s reaction to the treatment regimen he or she is a part of.

Mesothelioma Prognosis: Exceptions to the Statistics

As we said above, the statistical prognosis of mesothelioma is generally not in the patient’s favor. Seen only as a set of numbers, many people are understandably disheartened when they learn about their diagnosis. However, notable exceptions to these statistics do exist. Among the most famous of these exceptions was Dr. Stephen J. Gould of Harvard University. Dr. Gould was an internationally respected paleontologist and evolutionary biologist who conducted important research in both of these fields. Dr. Gould was diagnosed with peritoneal mesothelioma in 1982. After an initial period of depression, motivated by all of the negative statistics he read regarding his diagnosis, he became determined to not let the statistics regarding life expectancy rob him of all hope. When he died in 2002, it was from another form of cancer, totally unrelated to his mesothelioma. Dr. Gould has written about his experience with peritoneal mesothelioma and his determination to not let simple statistics dictate his reaction to his diagnosis in the essay, “The Median Isn’t the Message.” We recommend Dr. Gould’s essay for everyone who has been diagnosed with this disease, or with any other form of cancer.

Dr. Gould’s experience certainly may not be standard, but his hopeful approach to his disease cannot be discounted.

Mesothelioma Prognosis: Conclusion

As you can see, there are a number of factors that can impact the determination of a mesothelioma prognosis. The biologic facts of the disease as presented and the individual characteristics of the patient are all important co-factors and have serious implications for overall prognosis. Along with these factors, improving treatment regimens are another major element in one’s prognosis. There is still no cure for mesothelioma, but the treatments are improving, as is our knowledge of the actual mechanisms of the disease itself. Doctors are hopeful that we can translate our growing knowledge of the disease into more effective treatments and, therefore, better prognoses for patients.

Diagnosis

Diagnosing mesothelioma is often difficult, because the symptoms are similar to those of a number of other conditions. Diagnosis begins with a review of the patient's medical history. A history of exposure to asbestos may increase clinical suspicion for mesothelioma. A physical examination is performed, followed by chest X-ray and often lung function tests. The X-ray may reveal pleural thickening commonly seen after asbestos exposure and increases suspicion of mesothelioma. A CT (or CAT) scan or an MRI is usually performed. If a large amount of fluid is present, abnormal cells may be detected by cytology if this fluid is aspirated with a syringe. For pleural fluid this is done by a pleural tap or chest drain, in ascites with an paracentesis or ascitic drain and in a pericardial effusion with pericardiocentesis. While absence of malignant cells on cytology does not completely exclude mesothelioma, it makes it much more unlikely, especially if an alternative diagnosis can be made (e.g. tuberculosis, heart failure).

If cytology is positive or a plaque is regarded as suspicious, a biopsy is needed to confirm a diagnosis of mesothelioma. A doctor removes a sample of tissue for examination under a microscope by a pathologist. A biopsy may be done in different ways, depending on where the abnormal area is located. If the cancer is in the chest, the doctor may perform a thoracoscopy. In this procedure, the doctor makes a small cut through the chest wall and puts a thin, lighted tube called a thoracoscope into the chest between two ribs. Thoracoscopy allows the doctor to look inside the chest and obtain tissue samples.

If the cancer is in the abdomen, the doctor may perform a laparoscopy. To obtain tissue for examination, the doctor makes a small incision in the abdomen and inserts a special instrument into the abdominal cavity. If these procedures do not yield enough tissue, more extensive diagnostic surgery may be necessary.

http://www.cancerworldwide.com/imagini/lung_cancer_diagnosis.jpg

Typical immunohistochemistry results
Positive Negative
EMA (epithelial membrane antigen) in a membranous distribution CEA (carcinoembryonic antigen)
WT1 (Wilms' tumour 1) B72.3
Calretinin MOC-3 1
Mesothelin-1 CD15
Cytokeratin 5/6 Ber-EP4
HBME-1 (human mesothelial cell 1) TTF-1 (thyroid transcription factor-1)