What is Mesothelioma – Symptoms, Causes, Diagnosis and Treatment
In the last 40 years, there has been a rise in the reported cases of a rare cancer known as malignant mesothelioma. The ailment affects the inner linings of an organ and the most commonly affected site is the lungs. Though there are standard treatment options available to address the disease, its outlook is very poor. This article tries to answer all the aspects of the query,
what is mesothelioma?
In 70-80 percent cases, the diagnosed patients are found to be exposed to asbestos. Inhaling this substance along with smoking are the two major risk factors of developing this cancer.
What is Mesothelioma?
The lungs are covered by a membrane called mesothelium with two layers. These fibrous tissues produce a fluid which helps the lungs to move easily along with the other organs surrounding it. When the cells with which the mesothelium is formed are killed by the asbestos, a person is said to develop this rare ailment.
Nearly 2000 new cases of it are reported in the United States every year. Men are diagnosed more with it than women, though both the genders are at equal risk of developing it.
What are Mesothelioma Causes?
Cancer researchers have been searching for the mysterious cause of this disease. What confused them is the fact that how dead cells (killed by asbestos) could initiate the onset of this cancer. In 2010, a group of experts lead by scientists from the University of Hawai’i Cancer Research Center succeeded in resolving the mystery.
The results of their study were published in the June 28th online issue of the journal Proceedings of the National Academy of Sciences. The research was funded by the Mesothelioma Applied Research Foundation and the U.S. National Cancer Institute.
The study revealed that the killing of the cells of mesothelium by asbestos involves a process technically called “Programmed cell necrosis”. Here, a molecule known as high mobility group box 1 protein (HMGB1) is released at the time of the killing.
This protein causes swelling in the lungs or other affected organs. Its levels were found to be high in the blood of patients diagnosed with this cancer. The swelling in turn causes release of factors and initiation of the chain of following events which cause the onset of this cancer:
- Tumor suppressor genes getting inactivated
- Cancer causing genes called oncogenes being activated
- Normal genes becoming cancer causing ones owing to the adding of foreign DNA
- Activation of error prone enzymes which prevent any repairing of damage to the DNA
- Activation of telomerase which initiates uncontrollable cell division
- Prevention of natural programmed cell death – Apoptosis
What are Mesothelioma Symptoms?
- Abdominal pain
- Pain in the chest as fluid accumulates in the lungs and the surroundings
- Shortness of breath
- Swelling of the abdomen due to fluid accumulating in and around it
- Obstruction of bowel movement
- Abnormality in blood clotting
- Low count of the red blood cells technically known as anemia
- Swelling of neck
- Swelling of face
- Weight loss
- Hoarseness of voice
- Blood in the sputum
- Chest wall pain
- Clotting of blood in the arteries of lungs
- Low blood sugar level
- Severe bleeding in many organs
Characteristics of the Symptoms of Mesothelioma:
- It takes 15 to 50 years for the above mentioned symptoms of this cancer to become apparent.
- 20 million people in the United States exposed to the asbestos are at high risk of developing these signs.
- Though smoking is not directly responsible for the development of this ailment, it certainly aids in its progression.
- Latency of the signs by their very nature and ignorance about them in the general public are responsible for causing delay in diagnosis and commencement of the treatment.
- Moreover, they mimic the signs of other less serious conditions making it difficult even for the health care professionals to find the cancer.
Diagnosis of Malignant Mesothelioma:
The doctor hears the medical history of the patient and any exposure to asbestos in past. A physical examination is carried out followed by X-ray of the chest and lung functions test. These tests increase the suspicion of the disease.
A computer tomography or magnetic imaging resonance imaging technique reveals the build up of fluid around the lungs. Unfortunately, the process of cytology does not confirm the cancer. This is the reason why a biopsy of the suspected cells is carried out to become sure.
According to the TNM classification criteria recommended by the International Mesothelioma Interest Group, the stages of this cancer are from stage 1a to stage 4. Depending on the stage of the disease, aspects like
mesothelioma life expectancy
of the patient is predicted. It also decides the choice of treatment finalized by the doctor.
In spite of the developments in the available remedies, the outlook of the ailment has not improved much. The prognosis is better if the diagnosis is early. Complete cure is very rare.
The main culprits behind this condition are the very long period of the symptoms being latent and the easy and quick spreading of the malignant cells from the site of origin to the remote organs. Health status and age of the patient are other factors which influence the prognosis.
Treatment of Malignant Mesothelioma:
The standard treatments of this cancer are surgery, radiation therapy and chemotherapy. Their effectiveness is described below:
Depending on the size of the tumor, the doctor can either remove the part of the affected lining of the abdomen, lungs or the diaphragm.
The process involves application of high energy waves to kill the malignant cells and reduce the size of the tumor. This method is applied for those patients who cannot undergo surgery for medical reasons. However, in most of the cases this modality is found to be ineffective when applied alone. The rogue cells of a specific site are only killed.
Here anti-cancer drugs made up of potent chemicals are injected into the body through veins. The study is on to know the effectiveness of directly applying these drugs to the lungs. Among the available treatment options, chemotherapy is relatively more effective when applied alone. But, questions like when to begin it and the total number of phases required for the remedy are still unanswered.
In some cases, it is found that applying radiation therapy and chemotherapy after surgery has increased the
mesothelioma survival rate
of the patient up to five years.
A Duke University nation-wide research found that combination therapy increased the remission therapy of this cancer by 50 percent.
As a result, in 2009, the United States Food and Drug Administration approved the combined use of radiation and chemical drugs to treat cancer after surgery if it is diagnosed to be in stage 1 or stage 2.
The technique involves activation of molecules in the body like interleukin-2 (IL-2) which naturally strengthen the defense mechanism or the immune system of our body to fight against malignant cells.
But, the modality has proven to have varying results. In some trials, the method led to the development of side effects like fever and cachexia in patients. In other trails, 20 percent of patients were found to have reduction in their tumor mass by 50 percent.
Pain is relived by draining the accumulated fluid around the organs by inserting a needle or a thin tube. If it is done at the chest, the technique is called thoracentesis. If fluid from the abdomen is removed in this manner to provide relief, the method is called paracentesis. Drugs can be inserted through the tubes into these sites so as to prevent further accumulation of fluids.
Hopefully, this article covered all the aspects of the question –
What is mesothelioma
, in lucid manner.