Introduction
Mesothelioma is the most deadliest form of cancer caused due to previous exposure to asbestos. Mesothelioma develops when the malignant cells develop in the protective covering named peritoneal mesothelium protecting most of the body organs internally. Most of People suffering from mesothelioma cancer are the people working on the jobs where they inhale asbestos fibers or dust or the people inhaling asbestos in the cement environment or people inhaling asbestos while washing the asbestos stacked clothes. People working in the industries like cement, brake linings, roof shingles, flooring products, textiles, and insulation are more at risk.
Asbestos
Asbestos has also been shown to mediate the entry of foreign DNA into target cells. Incorporation of this foreign DNA may lead to mutations and oncogenesis by several possible mechanisms:
- Inactivation of tumor suppressor genes
- Activation of oncogenes
- Activation of proto-oncogenes due to incorporation of foreign DNA containing a promoter region
- Activation of DNA repair enzymes, which may be prone to error
- Activation of telomerase
- Prevention of apoptosis
Mesothelioma cancer does not usually spread to the bone, brain, or adrenal glands. Pleural tumors are usually found only on one side of the lungs.
Types of mesothelioma cancer
There are two main types of mesothelioma cancer. Pleural mesothelioma or lung cancer and peritoneal mesothelioma
- Pleural mesothelioma or lung cancer
Pleural mesothelioma is found to be the most lethal. Asbestos remains cut in to the inner layers of lungs and reach pleura mesothelium. After cutting mesothelium, these remains cause irritation and develop cancerous tumors and affects the lining surrounding and lubricating the lungs. Without lubrication expansion and contraction of lungs get affecting, resulting in to the abnormal exchange of oxygen and carbon dioxide
Signs and symptoms of Pleural mesothelioma:- Shortness of breath
- Persistent coughing
- Chest wall pain
- Wheezing and hoarseness
- Pleural effusions or fluid surrounding the lung
- Blood in the sputum coughed up
Diagnosis- Medical history of patient
- Chest X-ray. It shows the thickening of pleural wall, which is commonly due to asbestos exposure.
- Lung function tests
- CT scan or MRI
- If a large amount of fluid is present, abnormal cells may be detected by cytology
- Biopsy is needed if cytology is positive
- Detection of mesothelin related protein in the serum
- Thoracoscopy -. In this procedure, the doctor makes a small cut through the chest wall and puts a thin, lighted tube called a thoracoscope into the chest between two ribs. Thoracoscopy allows the doctor to look inside the chest and obtain tissue samples.
- Peritoneal mesothelioma
Asbestos fibers ingested and reached the digestive tract, these cut through the lining of stomach and intestines. Asbestos fibers here cut these organs and penetrate the peritoneal mesothelium, develop tumors and hence, develop peritoneal mesothelioma. As a result hinder the lubricating action of these organs. As a consequence these organs are no more able to lubricate and process the food.
Signs and symptoms of peritoneal mesothelioma:
- Weight loss and Cachexia
- Abdominal swelling and pain
- Bowel obstruction
- Anemia and fever
- Blood clotting abnormalities
- Abdominal mass
- Ascites, or an abnormal buildup of fluid in the abdomen
- If mesothelioma spread beyond mesothelium then it may cause pain, dangerous swelling, swelling of neck or face. But all the symptoms of mesothelioma develop after 20 to 50 years exposure of asbestos.
Diagnosis:- Medical history of patient
- Chest X-ray
- Detection of mesothelin related protein in the serum
- EMA (epithelial membrane antigen) in a membranous distribution
- Laparoscopy - To obtain tissue for examination, the doctor makes a small opening in the abdomen and inserts a special instrument into the abdominal cavity. If these procedures do not yield enough tissue, more extensive diagnostic surgery may be necessary.
Treatment
- Surgery
(a) Pleurectomy / decortication- lining of chest is removed. This is the most common surgery (b) Extra pleural pneumonectomy (EPP)- lining of the inside of the chest, the hemi-diaphragm and the pericardium are removed.
- Radiation
Tumor is highly resistant to radiotherapy and this is helpful in obstructing the major blood vessel and hence, prevents the growth of tumors.
- Chemotherapy
Pemetrexed is used for the treatment of malignant pleural mesothelioma. It is used in combination with Cisplatin.
- Heated Intraoperative Intra-peritoneal Chemotherapy
The surgeon removes as much of the tumor as possible followed by the direct administration of a chemotherapy agent, heated to between 40 and 48°C, in the abdomen. Perfuse the fluid for 60 to 120 minutes and then drain it. Heating the chemotherapy treatment increases the penetration of the drugs into tissues. Also, heating itself damages the malignant cells more than the normal cells.
