Stage 3, defined by Brigham
Tumors have spread from their origin in the pleura to the mediastinum, the middle part of the chest cavity, the chest wall and/or diaphragm. The contralateral lymph nodes are affected. These tumors are aggressively growing and cannot be removed with surgery (unresectable).
Stage 3, defined by TNM (aka IMIG)
The cancer affects the pleura, as well as one or more of the following: endothoracic fascia (connective tissue between the parietal pleura and the muscles and bones of the thoracic wall), mediastinal fat, chest wall and pericardium. The lymph nodes are affected (hilar, mediastinal, subcarinal and bronchopulmonary).
Stage 3, defined by Butchart
Tumors have spread to your diaphragm or peritoneum (serous membrane lining the abdominal cavity). Lymph nodes beyond the chest are also affected.
By this time, the symptoms of your condition are affecting your overall wellbeing. You’ll probably frequently experience chest pain, discomfort, breathing issues, dry cough, weight loss and fever, so much so that you’ll seek medical attention. It is common to be diagnosed with stage 3 mesothelioma because the symptoms become so apparent.
At this point, the tumors have become widespread. While extra pleural pneumonectomy surgery may still be an option, it would be extensive and may not be an effective treatment for some patients. The surgery involves the removal of the affected lung, parts of the chest and heart lining, lymph nodes, and diaphragm. Usually, a treatment plan includes more than one therapy (multimodal). Some doctors believe that radiotherapy and chemotherapy can help, both of which may be performed after surgery. Some patients may consider alternative medicine to complement their treatment.
The purpose of most treatments is to improve your comfort by minimizing the pain you experience from your symptoms. It is not to cure your condition.
Your chances of survival
The average life expectancy is about 16 months. Treatment can certainly extend your chances of survival, sometimes for several years.