Although the onset of the disease is insidious, once established, malignant mesothelioma progresses rapidly by local extension to the pericardium, mediastinum, and contralateral pleura. Pain and dyspnea (shortness of breath) become progressive. Extension to other thoracic structures creates superior vena cava syndrome, hoarseness, and dysphagia (difficulty swallowing). Abdominal extension is common and involves the abdominal lymph nodes and organs. Mesothelioma is associated with the development of paraneoplastic disorders, which include thrombocytosis, hemolytic anemia, Disseminated Intravascular Coagulation, and migratory thromboplebitis. Tumor recurrence rate after surgery is as high as 50%.
Death results from respiratory failure and local extension to other organs. Mesothelioma prognosis is poor. Untreated mesothelioma is fatal in 4-8 months. Patients who receive multimodality care may survive 16-19 months. The five-year survival rate is less than 5%.
As the disease progresses patients develop chest pain and shortness of breath.
Fatigue, dyspnea and hypoxia ensue. As the lesion invades thoracic structures, the following complications may develop:
There are three types of the disease. Mesothelioma is a tumor of the mesothelial cells which make up the lining that surrounds and protects the heart (pericardium), lungs (pleural) and abdomen (peritoneal). Pleural mesothelioma is the most common and affects the lungs. Pleural mesotheliomas can be benign or malignant,with the cancerous type being most common. Pleural mesothelioma prognosis is poor with approximately a 17-month survival from symptom onset. Peritoneal mesothelioma affects the abdomen and is the second most common of the mesotheliomas. Prognosis for peritoneal mesothelioma is worse at 10 months from symptom onset. There is a rare and benign form of peritoneal mesothelioma, seen mostly in young females. Pericardial mesothelioma affects the heart, this is the rarest of the three and prognosis is the poorest.
Overall prognosis is poor with a mean survival of 8-14 months. Staging is not routinely performed because of the overwhelming lack of surgical exploration. Rather, disease severity is determined to guide treatment. Therefore, information acquired at the time of diagnosis will provide some insight into the prognosis. Sarcomatous subtype histology (accounting for 10%) or uncertain histology is correlated with a poorer prognosis. Poor performance status, male gender and age over 75 consistently carry poor prognosis. Symptoms of chest pain and dyspnea as well as pleural involvement do not bode well for the patient. Certain lab tests will also indicate shorter survival, such as low hemoglobin, platelet count greater than 400 000, WBC count over 8300, or LDH over 500.
Unfortunately, the one year survival rate is only 50%. Excepting the case of stage I disease (a localized, non-invasive lesion), which can often be completely surgically resected, mesothelioma is usually fatal eventually, even with the best available treatment. Treatment strategy will depend on the location, size, and staging of the individual tumor and can include surgery (wedge resection, lobectomy, or pneumonectomy), chemotherapy, radiation, and photodynamic therapy (a chemically-targeted laser therapy). Numerous clinical trials are currently ongoing, which seek to improve survival rates for established therapeutic modalities (especially chemotherapy).
A good prognosis as the time of disease presentation is associated with the following:
A poor prognosis at the time of disease presentation is associated with the following:
The mean survival of patients with mesothelioma is generally between 6 and 19 months, regardless of therapeutic interventions. Most patients die from local tumor extension and respiratory failure. Also, tumor invasion may cause heart failure, stroke, arrhythmias, or even small bowel obstruction.