Treatments to Mesothelioma

It has been disappointing when considering the prognosis for malignant mesothelioma. Records have shown improvements in prognosis from recent multimodality and chemotherapy treatments. Treatments to this disease at earlier stages have a better prognosis, but cures are very rare. Analytical observation of the malignancy is affected by some factors such as the extremely long latency period between asbestos exposure and development of the disease, invasion to underlying tissue and other organs within the pleural cavity, and continuous mesothelial surface of the pleural cavity which favours local metastasis through exfoliated cells. The histological subtype and the patient's health status and age may help to predict prognosis. Below are some of the types of treatments to mesothelioma

Radiation - It is some times given post-operatively as a consolidative treatment, for patients with localized disease and who can tolerate a radical surgery. The entire hemi-thorax is treated with radiation therapy, mostly given simultaneously with chemotherapy. Administering radiation and chemotherapy after a radical surgery has led to extended life expectancy in selected patient populations with some patients surviving more than 5 years. Been part of a curative approach to mesothelioma, radiotherapy is usually applied to the sites of the chest drain insertion, to prevent growth of the tumor along the track in the chest wall.

This disease can generally resist curative treatment with radiotherapy alone, alleviative treatment regimens are some times used to relieve symptoms arising from tumor growth, such as obstruction of a major blood vessel. Radiation therapy when given alone with curative intention has never been shown to improve survival from mesothelioma. Necessary radiation dose to treat mesothelioma that has not been surgically removed could be considered very toxic.

Surgery - This by itself has proved to be disappointing. The median survival in one large scale was only 11.7 months. However, research has shown success when used in combination with chemotherapy and radiation.  A decortication/pleurectomy is the most common surgery, in which the lining the chest is removed. The less common one is an extrapleural pneumonectomy (EPP), in which the lung, pericardium, the hemi-diaphragm, and the lining of the inside of the chest are removed.

Chemotherapy - This can be considered to be the only treatment for mesothelioma that has been proven to improve survival on controlled and randomized trials. According to a study that showed a comparison of cisplatin chemotherapy alone with a combination of cisplatin and pemetrexed (brand name Alimta) chemotherapy in patients who had not received chemotherapy for malignant pleural mesothelioma previously and were not candidates for more aggressive "curative" surgery. This was the very first reported trial of a survival advantage from chemotherapy in malignant pleural mesothelioma, this showed a significant improvement in median survival from 10 months in the patients treated with cisplatin alone to 13.3 months in the combination pemetrexed group in patients who received supplementation with folate and vitamin B12. Vitamin supplementation was given to most patients in the trial and pemetrexed related side effects were significantly less in patients receiving pemetrexed when they also received daily oral folate 500mcg and intramuscular vitamin B12 1000mcg every nine weeks compared with patients receiving pemetrexed without vitamin supplementation. The objective response rate increased from 20% in the cisplatin group to 46% in the combination pemetrexed group. Some side effects which include stomatitis, nausea and vomiting, and diarrhoea were more common in the combination pemetrexed group but only affected a minority of patients and overall the combination of pemetrexed and cisplatin was well tolerated when patients received vitamin supplementation; both quality of life and lung function tests improved in the combination pemetrexed group.

However, there are some unanswered questions about the optimal use of chemotherapy, including when to start treatment, and the optimal number of cycles to give.

Other treatments include Heated Intraoperative Intraperitoneal Chemotherapy, Multimodality Therapy and Immunotherapy.