Mesothelioma – Cause Symptoms Diagnosis and Treatment

Posted on January 15, 2008. Filed under: Public Awareness, Scientific |

What is Mesothelioma?

Mesothelioma DiagramThe National Cancer Institute states that: “Malignant mesothelioma, a rare form of cancer, is a disease in which cancer (malignant) cells are found in the sac lining the chest (the pleura), the lining of the abdominal cavity (the peritoneum) or the lining around the heart (the pericardium).”

What is peritoneal mesothelioma?
Peritoneal mesothelioma is a cancer of the lining of the abdominal cavity. This form of cancer makes up approximately one-fifth to one-third of the total number of mesothelioma cases diagnosed.

Normal Lung AnatomyHow do you get Mesothelioma?
Most people with malignant mesothelioma have worked on jobs where they breathed asbestos. Others have been exposed to asbestos in a household environment, often without knowing it.

How much exposure does it take to get the disease? An exposure of as little as one or two months can result in mesothelioma 30 or 40 years later.

How long does it take after exposure for the disease to show up? People exposed in the 1940s, 50s, 60s, and 70s are now being diagnosed with mesothelioma because of the long latency period of asbestos disease.

What is the prognosis for mesothelioma?
Like most cancers, the prognosis for this disease often depends on how early it is diagnosed and how aggressively it is treated.

Is there any promising research or are there promising drugs for mesothelioma?

Research is being conducted at various cancer centers all over the United States as well as by pharmaceutical companies. A recent study of Alimta showed patients living much longer with Alitma than other chemotherapy drugs.

Mesothelioma’s Cause – Asbestos Exposure

At some point in our lives, nearly all of us have been exposed to asbestos in the air we breathe and the water we drink; from natural deposits in the earth, and from the deterioration of asbestos products around us. Most of us, however, do not become ill as a result of our exposure. More commonly, those who at some point are diagnosed with asbestos disease, have worked in jobs where more substantial exposure occurred over longer periods of time. Nevertheless, cases of mesothelioma have been documented as the result of lesser exposure, affecting family members of workers who came into contact with asbestos and brought it home on their clothing, skin or hair, or affecting those who lived in close proximity to asbestos manufacturing facilities. Symptoms of asbestos disease usually are not be apparent until decades after exposure.

Asbestos was used commercially in North America as early as the late 1800s, but its use increased dramatically during the World War II era when shipyards produced massive numbers of ships for the war effort. Since that time, asbestos-containing products were used by the construction and building trades, the automotive industry and the manufacturing industry. All told, more than 5,000 products contained asbestos.

For more than 50 years, products containing asbestos remained unregulated, and the manufacturers of those products continued to prosper, knowing full well that many of the millions of workers who came into contact with their products would ultimately suffer as the result of their actions. Finally, in the late 1970s, the Consumer Products Safety Commission banned the use of asbestos in wallboard patching compounds and artificial ash for gas fireplaces because the fiber could easily be released during use. In 1989, the Environmental Protection Agency banned all new use of asbestos, but uses established prior to that time were still allowed. Although awareness of the dangers of asbestos and public concern over the issue have led to a decline in domestic consumption over the years, a total ban on asbestos has not come to fruition. Asbestos is still imported, still used and still dangerous.

Although it is suggested that the number of mesothelioma cases in the U.S. has reached its peak and has begun to drop, a forecast released by the National Cancer Institute’s Surveillance, Epidemiology, and End Results Program (SEER), in April, 2003, projected the total number of American male mesothelioma cases from 2003-2054 to be approximately 71,000. This number, however, does not take into consideration events such as the World Trade Center disaster on September 11, 2001, when millions of New Yorkers were potentially exposed to air filled with carcinogenic asbestos particles. When the latency period for asbestos disease is factored in, cases of mesothelioma will continue to be diagnosed for years to come.

Mesothelioma Risk Factors

Anything that increases your chance of contracting a disease is considered a risk factor. Some examples would be strong exposure to sunlight as a risk factor for developing skin cancer, or smoking as a risk factor in developing lung cancer. In the case of mesothelioma, the primary risk factor is exposure to asbestos. Nevertheless, just as not everyone exposed to sunlight or smoke gets cancer, the same holds true for exposure to asbestos.

Asbestos, the name for a group of silicate fibers that occur naturally in the environment, was widely used in a variety of industrial products over a period of decades. Up to 8 million Americans may have been exposed at some point in their lives. According to the Environmental Protection Agency (EPA), up to 733,000 schools and other public buildings in the U.S. still contain asbestos insulation, and while most uses of asbestos have now been banned, there are still some asbestos-containing products on the market.

Asbestos has been used commercially since the late 1800s, however, its use was greatly increased during the World War II era when shipyards constructing warships were in full swing. Even today, statistics show that the highest number of mesothelioma cases diagnosed are in coastal areas where shipyards were in operation. Other at-risk trades include construction workers (particularly those who installed insulation), factory workers, mine and mill workers and railroad workers. It has also been proven that family members of exposed workers are at increased risk for developing mesothelioma because of secondary exposure to fiber brought into the home on the clothing, hair or skin of those who worked with or around asbestos products. For those ultimately diagnosed with mesothelioma, it may be 20 to 50 or more years to the onset of symptoms, and risk does not appear to diminish with time B — it is lifelong.

While the vast majority of mesotheliomas diagnosed are linked to asbestos exposure, there is the occasional report of patients with a history of Hodgkin’s disease contracting mesothelioma as a result of their radiation therapy. In these cases, mesothelioma develops on an average of 15 years post-treatment, and is most often located at the site of the radiated fields.

Mesothelioma’s Symptoms

The early symptoms of mesothelioma are generally non-specific, and may lead to a delay in diagnosis. Sometimes resembling viral pneumonia, pleural mesothelioma patients may present with shortness of breath, chest pain and/or persistent cough; some patients show no symptoms at all. A chest x-ray may show a build-up of fluid or pleural effusion (discussed below). The right lung is affected 60% of the time, with involvement of both lungs being seen in approximately 5% of patients at the time of diagnosis. Less common symptoms of pleural mesothelioma include fever, night sweats and weight loss. Symptoms of peritoneal mesothelioma may include pain or swelling in the abdomen due to a build-up of fluid, nausea, weight loss, bowel obstruction, anemia or swelling of the feet.

Pleural Effusion

One of the most common symptoms of mesothelioma is a pleural effusion, or an accumulation of fluid between the parietal pleura (the pleura covering the chest wall and diaphragm) and the visceral pleura (the pleura covering the lungs). Both of these membranes are covered with mesothelial cells which, under normal conditions, produce a small amount of fluid that acts as a lubricant between the chest wall and the lung. Any excess fluid is absorbed by blood and lymph vessels maintaining a balance. When too much fluid forms, the result is an effusion.
Types

Pleural effusion is broken down into two categories, transudates and exudates. A transudate is a clear fluid that forms not because the pleural surfaces are diseased, but because of an imbalance between the normal production and removal of the fluid. The most common cause of transudative fluid is congestive heart failure. An exudate, which is often cloudy and contains many cells and proteins, results from disease of the pleura itself, and is common to mesothelioma. To determine whether a fluid is a transudate or exudate, a diagnostic thoracentesis, in which a needle or catheter is used to obtain a fluid sample, may be conducted.
Symptoms

As the volume of fluid increases, shortness of breath, known as “dyspnea”, and sometimes pain, ranging from mild to stabbing, may occur. Some patients may experience a dry cough. When the doctor listens to the patient’s chest with a stethoscope, normal breath sounds are muted, and tapping on the chest will reveal dull rather than hollow sounds.
Diagnosis

Diagnosis of pleural effusion is usually accomplished with a simple chest x-ray, although CT scans or ultrasound may also be used. A special x-ray technique, called a lateral decubitus film, may be used to detect smaller effusions or to enable the physician to estimate of the amount of fluid present. If the underlying cause of the effusion is readily apparent (such as in the case of severe congestive heart failure), sampling of the fluid may not be necessary, however, because pleural effusion may be symptomatic of a number of disease processes from benign to malignant, a fluid sample is generally taken. Diagnostic thoracentesis, in which cells are extracted from the pleural cavity, is commonly done when the possibility of mesothelioma exists, however, in up to 85% of cases, the fluid tests negative or inconclusive even though cancer is present. It is ultimately a needle biopsy of the pleura (lining of the lung) or an open surgical biopsy which confirms a mesothelioma diagnosis.
Treatment

Pleural effusion caused by heart failure or infection can usually be resolved by directing treatment at the cause, however, when testing has realized no diagnosis, and fluid continues to build or recur, doctors may recommend chest tube drainage and chemical pleurodesis. Chemical pleurodesis is a technique in which a sclerosing agent is used to abrade the pleural surfaces producing an adhesion between the parietal and visceral pleurae. This will prevent further effusion by eliminating the pleural space. Talc appears to be the most effective agent for pleurodesis, with a success rate of nearly 95%. It is highly effective when administered by either poudrage or slurry. Poudrage is the most widely used method of instilling talc into the pleural space. Before spraying the talc, the medical team removes all pleural fluid to completely collapse the lung. After the talc is administered, they inspect the pleural cavity to be sure the talc has been evenly distributed over the pleural surface. Some doctors prefer to use talc mixed with saline solution which forms a wet slurry that can roll around the pleural cavity.

Advertisements

Pages: 1 2 3 4

Make a Comment

Leave a Reply

Please log in using one of these methods to post your comment:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

Liked it here?
Why not try sites on the blogroll...

%d bloggers like this: