What is Mesothelioma?

Malignant mesothelioma is cancer that forms in the mesothelium, or the thin layer of cells that surround major organs. Mesothelioma is almost always caused by exposure to asbestos. There are three common locations for mesothelioma to form:

• Pleura – the chest and lung area
• Peritoneum – the abdomen area
• Pericardium – near the heart

In general, the average life expectancy for mesothelioma patients is between 12 to 21 months. Some 40 percent of patients survive about a year after a diagnosis and about 20 percent live more than two years following a diagnosis. While rare, there are some patients who live longer than five years with the disease.

The patient’s age at diagnosis, general health and access to treatment specialists are among the many factors that go into determining a mesothelioma patient’s life expectancy. Other factors that play a key role are the location of the disease (pleural mesothelioma patients have better survival rates than other disease locations), cell types involved (epithelial cells respond better to treatment than other types) and stage (earlier stage disease is more responsive to treatment). Experts warn that life expectation estimations vary greatly by patient and individual circumstances.

The primary cause of any form of mesothelioma is exposure to the thin, fibrous mineral called asbestos. When asbestos fibers are inhaled, they travel through the lungs to reach the pleura, where they cause inflammation and scarring to form pleural mesothelioma. In cases of peritoneal and pericardial mesothelioma, researchers suspect asbestos fibers are ingested, travel through the lymph system or are absorbed through the skin to irritate surrounding cells. In all cases, the irritations damage cell DNA, causing cells to grow rapidly and abnormally and forming tumors.

Small studies have indicated some people are genetically predisposed to developing mesothelioma because they are more susceptible to the dangers of asbestos. Researchers are also reviewing a link between mesothelioma and Simian virus 40 (SV40), a DNA virus that contaminated early polio vaccines. There has been no definitive link between the virus and mesothelioma.

Physicians determine the stage of disease by performing numerous tests including X-rays, CT (CAT) scans, MRIs, PET scans and biopsies. It is important to determine where the cancer started and if it has spread from the point of origin for a correct disease staging. An accurate assessment of disease stage is crucial to successful treatment options.

Most physicians use a universally accepted tumor grading system to stage the disease. This allows physicians to communicate about a single patient to devise the best treatment plan. The TNM system looks at the size and growth of tumors (T), the involvement of lymph nodes (N) and the metastasis, or spread, of the disease (M). From there, the cancer is staged, with stages I and II as the early disease process and stages III and IV as the more advanced disease. Most cases of mesothelioma are diagnosed in the later stages, making treatment difficult.

About 55 percent of mid- to late-stage mesothelioma patients live six months after a diagnosis, some 40 percent survive the first year after a diagnosis and about 9 percent survive five years or longer. An overall survival rate is dependent on a number of factors including state and location of the disease, the patient’s age and general health and the access to treatment specialists. Long-term survivors credit lifestyle changes, alternative medicine and treatment from mesothelioma specialists as contributing factors to their success.

A recent study that looked at 20 years of survivor information, from 1992 to 2012, found pleural and peritoneal survivorship was on the rise. The study found recent advances in treatment, including hyperthermic intraperitoneal chemotherapy (HIPEC) and cytoreductive surgery, appear to have increased survival rates in peritoneal mesothelioma patients. The study’s author suggested genetics, various treatment modalities and gene environment interactions might also play a part in patient longevity.

The optimal treatment approach for most mesothelioma patients is multimodal therapy which is surgery, chemotherapy and radiation. This approach, if successful, eliminates diseased tissue and allows for palliative care. Your treatment plan will depend on your diagnosis, disease stage and overall health.

• The most aggressive surgery calls for stripping away the diseased mesothelium, the thin layer of cells surrounding major organs, or removing a diseased lung entirely. This potentially curative surgery is most suited to patients who are in the early stages of mesothelioma.
• Hyperthermic intraperitoneal chemotherapy (HIPEC), or heated chemotherapy, has been found to be effective against mesothelioma tumors. Used before and after surgery, radiation shrinks tumors and kills cancer cells.
• Another widely used option, especially for those looking for treatments in advanced stages, are clinical trials. These allow patients to pursue treatments that are proven beneficial but are not yet approved by the FDA.

For decades, all branches of the military required asbestos be used to protect service members from heat, fire and chemical threats. It was widely used in barracks, offices, vehicles and vessels. Over a period of 50 years, some 5 million veterans were exposed to asbestos in shipbuilding operations alone. About 30 percent of mesothelioma patients are U.S. military veterans. Occupations that include carpentry, construction, roofing, auto mechanics and milling are at risk for exposure to dangerous levels of asbestos.

It is estimated that more than 300 asbestos products were used on military installations and in military applications between the early 1930s and the late 1970s. More recently, soldiers serving in Iraq, Afghanistan and the Middle East may be been exposed from airborne asbestos. Companies that produced these products concealed the dangers of mesothelioma to put profits ahead of the safety and well being of our troops.

Gender, age, severity of symptoms, level of asbestos exposure, stage of disease and disease cell type play a significant role in the overall prognosis for mesothelioma patients. In addition, external factors including diet, age, stress level and general health play a role. The average pleural mesothelioma patient with late-stage disease survives about 12 months after a diagnosis, but those treated with surgery and radiation may extend their prognoses by some 28 months. Peritoneal mesothelioma patients who are treated with heated intraperitoneal chemotherapy (HIPEC) outlive their prognoses by 24 months to 7 years.

Many patients are able to improve their prognosis by seeking treatment options from a qualified mesothelioma specialist. Doctors who are practiced and trained in mesothelioma disease treatment approaches have specialized skills, education and access to crucial information that can make positive changes on long-term health.