In order to determine the patient’s mesothelioma staging, doctors must follow one of several different staging systems currently being used to determine the severity of the disease. In order to create a treatment plan for mesothelioma, accurate staging is crucial. Mesothelioma staging can be defined as “a process that is used to determine if and how far the mesothelioma cancer has spread outside the pleura or peritoneum and just how far the disease has spread.”
There are four mesothelioma stages include stage I (a and b), stage II, stage III and stage IV. Stage I mesothelioma, the earliest stage, affects the outer layer of the pleura around the chest wall. It only affects one side of the chest. In stage I (Ia), the mesothelioma may have grown in the pleural tissue that covers the muscle that separates the thoracic (chest) cavity from the abdomen – the diaphragm. Stage I (Ib) mesothelioma means that the disease is in the beginning stages of spreading to the inner pleural layer, but it is still on one side of the chest.
In stage II of the disease, the malignant mesothelioma has enlarged to form a tumor on the pleural tissue around the lungs or it is already spreading into the lung tissue or diaphragm. It has spread to both layers of the pleura on only one side of the body.
In stage III, the mesothelioma has spread to the pericardium (the covering of the heart), the chest wall or the //medical-glossary/l/lymph-nodes on the same side of the chest.
Stage IV mesothelioma is the most advanced of all stages. Stage IV mesothelioma means that the mesothelioma has spread to different parts of the chest wall. It may have also grown through the diaphragm and into the peritoneum, to the pleura on the opposite side of the body, to the chest organs, or through the inner layer of the covering of the heart or pericardium. Stage IV mesothelioma may have also spread into the lymph nodes on the opposite side of the body, above the collarbones, or to other parts of the body.
Doctors may use one of three different staging systems to determine the severity of mesothelioma, once the type of the disease (Pleural mesothelioma is the most common, followed by perintoneal mesothelioma, and the most rare, pericardial mesothelioma) has been determined. These staging systems include the Butchart Staging System, the TNM Staging System, and the Brigham Staging System.
The Butchart staging system was created by M.D. and cardiothoracic surgeon Eric G. Butchart and it is the oldest of all staging systems. It is based on the magnitude of the primary tumor mass. While the Butchart staging system has been around since the 1970’s, it is still currently being used by many specialists for its advantage of simplicity and relevance to prognosis and therapeutic options. The Butchart staging system uses the four stages listed above with similar characteristics.
The TNM staging system was created by the American Joint Committee on Cancer (AJCC). The TNM staging system is considered the major staging system. T stands for tumor and it refers to the tumor size and how far it has spread to nearby organs; N stands for “spread to lymph nodes,” and M stands for Metastasis. This means whether the mesothelioma has spread to other (distant) organs. The TNM Staging System assigns categories and numbers to determine the overall mesothelioma stage.
The Brigham staging system is the newest staging system for mesothelioma. Fifty-two patients were treated with trimodality therapy at the Dana-Farber Cancer Institute/Brigham and Women’s Hospital Thoracic Oncology Program in Boston Massachusetts. The Brigham staging system was introduced shortly after analyzing these patients. The Brigham staging system allows for four stages and it is based on whether the mesothelioma can be treated or removed by surgery. It is also based on whether or not the body’s lymph nodes are involved. The Brigham stages are similar to the TNM system.
During the mesothelioma staging process, several tests and procedures may be used. They include: a chest x-ray, a CAT scan (CT scan), magnetic resonance imaging (MRI). and endoscopic ultrasound. Chest x-ray involves an x-ray of all of the bones and organs inside the chest. A CAT scan is a procedure that takes pictures from different angles of the abdomen and chest. Also called computed tomography, computerized tomography, or computerized axial tomography, CAT scan images are created by a computer linked to an x-ray machine and in some cases a dye may be swallowed or injected making tissues and organs easier to see.
Magnetic resonance imaging (MRI), or nuclear magnetic resonance imaging (NMRI), uses a magnet, radio waves, and a computer to create detailed pictures of the abdomen or chest. Endoscopic ultrasound (EUS) is also called endosonography. It is a procedure that involves the insertion of an endoscope (a thin, tube-like instrument with a light and a lens for viewing) into the body. A probe at the end of the endoscope bounces high-energy sound waves (ultrasound) off internal tissues or organs. This creates echoes, which form a picture of body tissues. The picture of body tissues is called a sonogram. Endoscopic ultrasound may be used to help guide a fine-needle aspiration (FNA) biopsy of the lymph nodes and lung as well as other areas of the body.
Once the stage, type of mesothelioma, and overall health of the patient have been determined, the doctor will explore the various treatment methods. The treatments and methods used for treating mesothelioma can be divided into two types: traditional mesothelioma treatments and new mesothelioma treatments.Traditional mesothelioma treatments include: surgery (pleurectomy/decortication or P/D, extrapleural pneumonectomy, pleurodesis, peritonectomy), cheotherapy(anti-cancer drugs, which are usually injected into a vein), and radiation therapyor radiotherapy.
New mesothelioma treatments include gene therapy, photodynamic therapyor PDT, immunotherapy, intensity modulated radiation therapy or IMRT, and the development of new chemotherapy agents. In addition to these new (or radical) mesothelioma treatments, there are several other radical treatments available including angiogenesis therapies, antineoplaston therapy, mesothelioma clinical trials, interferon and interleukin therapy, and radiofrequency ablation.