Malignant mesothelioma differs from other forms of cancer in several ways: it affects the mesothelium tissue that lines organs in the body; it is rare and almost exclusively caused by asbestos exposure; it is aggressive and spreads rapidly, and it even has a unique genetic makeup.
What Makes Mesothelioma Unique?
Like other cancers, mesothelioma is a malignant disease. It results from changes to DNA in cells that make them grow and divide rapidly. Ultimately, without treatment, any type of cancer is fatal as the tumors spread to other tissues and organs. Mesothelioma, though, has many unique aspects that differ from other cancers.
Asbestos Exposure
Few cancers have one primary cause. In the case of mesothelioma, the leading cause is past exposure to asbestos. Asbestos fibers stick in tissues in the body, causing damage to cells that, in some people, results in cancer.
Not everyone exposed to asbestos will develop mesothelioma. Some people get mesothelioma without known exposure. But overwhelmingly, the main cause of this cancer is this one type of exposure.
Long Latency Period
With a known cause, researchers have been able to measure the latency period for mesothelioma, which is unusually long. The latency period is the time between exposure and the onset of symptoms and a diagnosis.
Mesothelioma has a very long latency period, ranging from 14 to 72 years or even longer. The average latency period is 49 years.[1]
Is Mesothelioma the Deadliest Type of Cancer?
There is no single type of cancer that is deadliest for all people. However, mesothelioma is one of the most aggressive cancers. It spreads rapidly, is difficult to diagnose, and evades treatment. This makes it deadlier than many other cancers.
The prognosis for mesothelioma is generally poor compared to other cancers, especially when diagnosed in the later stages. Survival times are often short, even with aggressive treatments.
How Is Mesothelioma Different from Lung Cancer?
The type of cancer most often confused with mesothelioma is lung cancer, especially adenocarcinoma. Although they have some similarities, there are many important differences between them.
Mesothelioma Is Not a Type of Lung Cancer
This is a common misconception. Mesothelioma is not a type of lung cancer. They are two completely separate cancers.
The most common type of mesothelioma is pleural, which involves tissue surrounding the lungs. This is one reason it is often thought to be the same as lung cancer.
Tumor Growth Is Different
Lung cancer tumors tend to grow as individual masses with well-defined boundaries. Mesothelioma tumors are more diffuse. They spread through the pleural tissue with poorly defined boundaries, eventually growing together.
Mesothelioma Is Rarer Than Lung Cancer
Only about 3,000 cases of mesothelioma are diagnosed in the U.S. each year.[2] On the other hand, lung cancer is the third most common type of cancer, accounting for over 230,000 new cases each year.[3]
Causes
Mesothelioma is almost always caused by asbestos exposure. Smoking is the leading cause of lung cancer. Asbestos can also cause lung cancer.
Diagnosis
Because mesothelioma is very rare, it is often misdiagnosed as lung cancer, especially on imaging tests. A biopsy is required to differentiate between the two similar forms of cancer.
A biopsy is a sample of cancer cells taken from the patient. A pathologist examines the cells under a microscope to determine their type and origin.
Tests for biomarkers, which measure the chemical markers of each type of cancer to some degree, can also be helpful. These markers can support one diagnosis or the other.
Does Mesothelioma Treatment Differ from Other Types of Cancer Treatment?
Although treatments for mesothelioma may involve surgery, chemotherapy, radiation therapy, and gene therapy, the aggressive nature of mesothelioma often calls for combined treatments.
These combined treatments could include surgical tumor removal followed by radiation therapy to eradicate any remaining cancer cells.
Because mesothelioma is often diagnosed in later stages when curative treatments do little good, treatment is often only palliative. Palliative treatments aim at lessening discomfort and pain caused by cancer rather than killing cancerous tissues.[4]
Is Mesothelioma Similar to Any Other Type of Cancer?
Pleural mesothelioma is most similar to the type of lung cancer called pulmonary adenocarcinoma.[5] Early symptoms of these two cancers are similar, including chest pressure, difficulty breathing, and fatigue.
Although both forms affect the epithelium (a tissue that lines the body’s organs), mesothelioma tends to grow in the outer layer of the epithelium, while adenocarcinoma is more common in the inner layer. Mesothelioma is also unusually aggressive, growing and spreading at a far greater rate than adenocarcinoma.
As the name suggests, the subtype sarcomatoid mesothelioma has features similar to sarcoma. Sarcoma is another rare cancer that can occur in smooth tissues, muscles, or bones.
Mesothelioma: Genetically Unique
Another way mesothelioma differs from other cancer types is in the genetic makeup of the cancer cells. Mesothelioma is genetically unique from other cancer types. A biopsy can determine what molecular structure the genes of a piece of cancer tissue has.
If signs point to malignant mesothelioma, the appropriate treatment can be taken. Advancements in genomics and genetic science yield new hope for proper diagnoses.
Is Testicular Mesothelioma Unique from Other Types of Testicular Cancer?
Yes. Testicular mesothelioma is a rarity among an already rare form of cancer. Testicular mesothelioma typically affects the membrane covering the testes, while other forms of testicular cancer usually form in the testes themselves, particularly the cells that govern the creation of sperm.
Another distinct difference is the rarity. Testicular mesothelioma is the rarest type of mesothelioma there is while other forms of testicular cancer are relatively common. There have been fewer than five hundred confirmed diagnoses of testicular mesothelioma.
Other types of testicular cancer are highly curable and show few incidences of recurrence. Mesothelioma is often difficult to treat because it tends to grow rapidly and spread. Compared to other types of mesothelioma, testicular mesothelioma has longer survival times.
While mesothelioma is similar to other cancers in its basic features, it is also unique. It has a longer latency, often a single cause, and is rare and difficult to treat. As researchers continue to investigate this cancer, they discover more about it in comparison to other cancers.
