What is Mesothelioma?

Understanding Mesothelioma

Asbestos exposure is a proven cause of mesothelioma. An industrial building material used up until the 1980s, asbestos was used in every military branch. Many veterans are still being diagnosed with mesothelioma.

Mesothelioma starts in the lining of vital organs, usually the lungs. These linings are made of mesothelial cells. The American Cancer Society says, “The mesothelium helps protect your organs by making a special lubricating fluid that allows organs to move against each other.” Mesothelioma gets its name from the lining it affects.

There are three main locations where mesothelioma can form:

• Pleural Mesothelioma. Affecting the lining of the lungs, pleural mesothelioma is caused by inhaling asbestos fibers. The body tries to rid itself of the fibers, but coughing does not bring up the tiny needle-like particles. Over time, the asbestos particles cause inflammation in the mesothelium of the lung (called the pleura). The fibers cause healthy cells to mutate into cancer cells.
• Peritoneal Mesothelioma. Occurring in the lining surrounding the abdomen (called the peritoneum), peritoneal mesothelioma is the second most common of the three disease locations. It’s believed to be caused by swallowing asbestos fibers, leading to inflammation of the abdominal lining.
• Pericardial Mesothelioma. Affecting the lining of the heart (called the pericardium), pericardial mesothelioma is the rarest form of mesothelioma. Researchers aren’t entirely sure how it develops. One theory is that asbestos fibers travel through the bloodstream and become lodged in the pericardial lining.

Mesothelioma causes tumors (clumps of cancer cells) to form within the mesothelium linings. These tumors grow and spread. In advanced mesothelioma, the cancer has spread into the lymphatic system—the part of the body responsible for cleaning the blood of harmful substances. If the lymphatic system can no longer protect the body, mesothelioma spreads faster.

Mesothelioma is often diagnosed late because it’s rare and has vague symptoms. Because it often goes undetected for months or years, mesothelioma has a poor prognosis. Some people diagnosed with mesothelioma are given a life expectancy of between 12 and 18 months. But many people outlive their prognosis thanks to good treatment.

Mesothelioma patients are typically male due to asbestos being a substance commonly used in male-dominated industries. Most patients are over 60 years old because it takes decades for the disease to emerge.

General Facts About Mesothelioma

• Rare cancer caused by exposure to asbestos
• Affects the lining of the lung, abdomen or heart
• Most commonly diagnosed in males over the age of 60
• Has a latency period of 15 to 45 years
• Veterans comprise almost one-third of all mesothelioma cases
• Commonly diagnosed at late, advanced stages
• Specialized treatments include surgery, radiation and chemotherapy
• Mesothelioma specialists are available at select VA hospitals
• Veterans with mesothelioma are entitled to compensation and benefits if they were exposed to asbestos in the military

Mesothelioma Types

Mesothelioma affects different parts of the body. Each type of mesothelioma is distinguished by the location where the disease started.

Pleural Mesothelioma

Pleural mesothelioma is the most common disease location. It makes up 85-90% of all mesothelioma cases. Pleural mesothelioma affects the protective lining that covers the lungs, called the pleura. There are two layers of pleura with a space between them.

Pleural tumors can cause fluid buildup in the pleural space—a pleural effusion. Effusions can cause symptoms such as shortness of breath and tightness in the chest. Over time, mesothelioma can spread to the outer chest cavity or nearby lymph nodes in the armpits or collarbone.

Pleural mesothelioma has a poor prognosis compared to peritoneal mesothelioma. Approximately 40% of pleural mesothelioma patients survive longer than 12 months. Patients who have had surgery, like an extrapleural pneumonectomy (EPP) often live much longer than their initial prognosis.

Peritoneal Mesothelioma

Peritoneal mesothelioma is the second most common form of mesothelioma, making up 10-15% of all cases. Peritoneal mesothelioma usually has a better prognosis than pleural or pericardial mesothelioma. The average life expectancy for peritoneal mesothelioma patients is 12 months after diagnosis. Many patients live several years after their diagnosis thanks to a procedure involving cytoreduction surgery (which removes visible cancer tissue) followed by chemotherapy using heated drugs (called HIPEC).

Peritoneal mesothelioma affects the lining of the abdominal cavity, called the peritoneum. The peritoneum protects the organs inside the abdomen. These organs include the stomach, pelvic organs and part of the diaphragm.

Mesothelioma tumors can create fluid buildup in the peritoneum (ascites), causing symptoms like stomach aches and abdominal bloating.

Pericardial Mesothelioma

Pericardial mesothelioma is the least common form of mesothelioma. Less than 1% of all mesothelioma diagnoses are of this type. Pericardial mesothelioma affects the protective lining that covers the heart, called the pericardium. Unlike pleural and peritoneal mesothelioma, researchers still aren’t sure how pericardial mesothelioma develops.

To date, there have been fewer than 500 cases of pericardial mesothelioma worldwide. Pericardial mesothelioma has the poorest prognosis of all types. Half of all patients live only 6 months after their diagnosis. 

Cancer that surrounds the heart is very difficult to treat. Mesothelioma specialists use a combination of surgical procedures and anti-cancer drugs to help remove tumors and slow disease progression.

Mesothelioma Cell Types

Cell type refers to how mesothelioma cells look under the microscope. Pathologists study these cells to help make a conclusive diagnosis.

There are three cell types that can appear in any of the three mesothelioma locations (pleural, peritoneal and pericardial):

1. Epithelioid cells: Epithelioid cells are the most common and the easiest to treat. They appear regularly under the microscope. They don’t divide and spread as aggressively as sarcomatoid cells.
2. Sarcomatoid cells: Sarcomatoid cells are the least common and most aggressive mesothelioma cell type. They appear irregularly under the microscope. They divide and spread quickly. Sarcomatoid mesothelioma is the most difficult form of mesothelioma to treat.
3. Biphasic: Biphasic mesothelioma tumors have both epithelioid and sarcomatoid cells. These tumors are sometimes referred to as “mixed” cell type. A biphasic tumor takes on the characteristics of whichever cell type is most dominant. Doctors consider a biphasic tumor with epithelioid-dominant cells to be easier to treat than one with sarcomatoid-dominant cells.

Mesothelioma Symptoms

Mesothelioma symptoms vary depending on the cancer location. Symptoms can take 1-5 decades to appear after asbestos exposure. This interval of time is known as a latency period. For this reason, the symptoms are often difficult to identify and easy to ignore.

The latency of mesothelioma symptoms causes confusion with physicians who have limited experience with this rare cancer. Seeking consultation and treatment from a specialist is critical. A second opinion can ensure you receive the best treatment possible to extend your life.

Pleural Mesothelioma Symptoms

Because pleural mesothelioma affects the lining of the chest cavity, the symptoms mostly cause difficulty breathing.

Here are the symptoms of pleural mesothelioma:

• Frequent dry or painful coughing
• Coughing up blood (hemoptysis)
• Shortness of breath
• Tightening across the chest
• Fluid buildup in the lungs (pleural effusion)
• Lumps of tissue building under the skin around the chest
• Weakness and fatigue
• Fever and sweating
• Unexplained weight loss

Many of the initial symptoms, like shortness of breath, can be confused with other respiratory conditions.

Peritoneal Mesothelioma Symptoms

Peritoneal mesothelioma produces symptoms that affect digestion.

Here are the main symptoms of peritoneal mesothelioma:

• Bowel troubles
• Abdominal pain
• Abdominal swelling
• Tissue lumps under the skin of the abdomen
• Anemia
• Fever
• Fatigue
• Fluid buildup (ascites)
• Blood clots

Pericardial Mesothelioma Symptoms

Pericardial mesothelioma produces a mixed set of symptoms related to the heart.

Here are some symptoms of pericardial mesothelioma:

• Chest pain
• Shortness of breath
• Cough
• Irregular heartbeat
• Heart murmurs
• Fluid buildup in the pericardium (pericardial effusion)
• Fatigue
• Swollen face and arms

Mesothelioma Causes

Mesothelioma is caused by asbestos exposure. Asbestos is a natural substance made up of tiny microscopic fibers—it’s strong and durable. It was commonly used in construction as an insulator and fire retardant.

Until the 1980s, asbestos was used extensively by the military. Army barracks, vehicles, vessels and aircraft all contained asbestos. Service members who worked in onboard ships or in a shipyard were at the greatest risk of exposure.

When asbestos is disturbed or moved, it releases its sharp fibers into the air. Anyone working around asbestos may accidentally inhale or ingest asbestos fibers. When the fibers are inhaled or ingested, they can migrate deep within the tissue layers covering the chest cavity, abdomen or heart.

Over time, the fibers cause irritation and inflammation in the linings. It’s not known exactly how, but this irritation from asbestos fibers can cause surrounding healthy cells to mutate into cancer cells. Cancer cells divide and spread at faster rates than most healthy cells. As they divide, they clump together to form masses of cancer cells called tumors. These tumors continue to spread and shut down systems and organs in their path.

Mesothelioma Diagnosis

Mesothelioma can be difficult to diagnose, due to its initial symptoms being vague. These symptoms can easily be confused with other conditions like bronchitis or irritable bowel syndrome. Many physicians and general oncologists have never encountered a mesothelioma patient and don’t always know what to look for.

Here are the basic steps of a mesothelioma diagnosis:

1. Physical Exam. The patient’s primary care physician will review symptoms, family history and assess possible causes. For veterans with known asbestos exposure, it is imperative that he/she mention this exposure to their doctor during the initial exam.
2. X-Rays and Imaging Scans. X-rays, ultrasounds and CT scans are important diagnostic tools for narrowing in on the cause of the patient’s symptoms. These tests help specialists see where the mesothelioma has formed and how advanced it is.
3. Biopsies. Once X-rays or imaging scans have revealed the location of any tumors, a biopsy is ordered. A biopsy is a tissue sample collected from the tumor that is analyzed under a microscope. This helps pathologists determine if the tumor is mesothelioma. The pathologist also determines the cell type. Cell type allows specialists to recommend the best and most appropriate treatment course. A biopsy is the only conclusive way to diagnose mesothelioma.

A general oncologist may be able to diagnose mesothelioma, but most are unfamiliar with specialized treatment and surgeries for mesothelioma. If you were diagnosed by a general oncologist, consider getting a second opinion from a mesothelioma specialist. A second opinion can present a better prognosis or new treatment options.

Mesothelioma Stages

The stages of mesothelioma explain how advanced a patient’s disease is. Stages explain how large a patient’s tumors are and how far the disease has spread. Doctors also look at a patient’s stage to determine which treatments are best for that individual.

Pleural mesothelioma has 4 stages. They are ranked from least advanced to most advanced.

Doctors stage pleural mesothelioma using the following criteria:

• Stage 1. This is the least advanced stage of pleural mesothelioma. It’s broken into 2 sub-stages.
  • Stage 1A: Mesothelioma is still localized within the pleura around one lung on one side of the chest. Mesothelioma cells are contained in the outer layer of the pleura (parietal pleura) on one side of the chest.
  • Stage 1B: Mesothelioma cells are contained in the inner layer of the pleura (visceral pleura) on one side of the chest.
• Stage 2. Mesothelioma cells are in both the inner and outer layers of the pleura. The tumor mass has enlarged within the pleural tissue around one lung, or the tumor has spread to the diaphragm or lung tissue. There is minimal lymph node involvement.
• Stage 3. Mesothelioma cells have spread through the pleura. They are now attached to the chest wall or the covering of the heart (pericardium). Or the tumor has spread to the nearby lymph nodes on the same side of the chest as the affected lung.
• Stage 4. Mesothelioma cells are now affecting multiple parts of the chest wall. The cells have spread through the diaphragm and into the peritoneum, or the mesothelioma cells have spread to the other side of the chest and into the pleura of the other lung.

Seeking Mesothelioma Treatment

Mesothelioma specialists have the best understanding of the disease. This also means they have access to the most cutting-edge treatments. They are highly trained in determining disease progression, surgical options and in prescribing treatments that provide veterans the greatest chance of significantly improving their prognosis.

Key aspects of mesothelioma treatment:

• Get a second opinion from a mesothelioma specialist.
• Surgery offers the best chances for long-term survival.
• Every patient has a chance to improve their prognosis.

If you have been diagnosed with mesothelioma, contact one of our patient advocates to get connected with a mesothelioma specialist or assistance in filing a VA claim.