Mesothelioma Staging - TNM Staging System

There are several staging systems currently being used to determine whether patient’s are in the early stages of the disease or the advanced stages. Mesothelioma staging is absolutely necessary in order to create an effective treatment plan for mesothelioma patients. The staging systems include the Butchart Staging System, the Brigham Staging System, and the TNM Staging System.

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.

There are four mesothelioma stages doctors may assign once TNM staging is complete. They are: stage I, stage II, stage III and stage IV.

Stage I means that the mesothelioma involves the right pleura or left pleura. The cancer may also have spread into the lung, pericardium, or diaphragm on the same side. In stage I, the mesothelioma has not spread to the lymph nodes.

Stage II means that the mesothelioma has spread from the pleura on one side to the peribronchial and/or hilar lymph nodes next to the lung on the same side. The mesothelioma may have also spread into the diaphragm on the same side as well as into the  lung and pericardium on the same side.

Stage III means that the mesothelioma has spread into the chest wall muscle, the esophagus, the heart and the ribs. It may have also spread into other organs in the chest on the same side as the main tumor, with or without spreading to subcarinal and/or mediastinal lymph nodes on the same side as the main tumor.

Stage IV means that the mesothelioma has spread into the lymph nodes in the chest on the opposite side of the location of the primary lung tumor, or it directly extends to the pleura or lung on the opposite side, directly extends into the peritoneum, or directly extends into organs in the neck or abdominal cavity.  It is important to keep in mind that any mesothelioma with evidence of distant metastases or mesothelioma that has spread to organs beyond the abdomen or chest is included in Stage IV.

During the staging process, several tests and procedures may be used including chest x-ray, 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 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), chemotherapy (anti-cancer drugs, which are usually injected into a vein), and radiation therapy or radiotherapy.

Radiation therapy or radiotherapy involves the use of high-energy rays to shrink tumors and kill cancer cells, but it only affects the cancer cells in the treated area only. There are two types of radiotherapy including external radiation and internal radiation therapy. External radiation is generated through a machine and internal radiation therapy is delivered directly to the source of the cancer by placing radioactive materials into the body through small tubes. In many cases a trimodality approach is employed, which means several treatments are combined for the best outcomes, for a better chance at long-term survival, and/or a better quality of life.

New mesothelioma treatments include gene therapy, photodynamic therapy or 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. A wide variety of complementary and alternative mesothelioma treatments also exist such as herbal products, special diets, homeopathic medicine, acupuncture, therapeutic massage, high dose vitamin C, laetrile (amygdalin, extracted from fruit pits), and Eastern medicines.

Following is a brief description of the other two mesothelioma staging systems. 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 Brigham staging system also uses four stages. It is based on whether the mesothelioma can treated or removed by surgery. It is also based on whether or not the body’s lymph nodes are involved.

'Mesothelioma Staging - TNM Staging System' Resources:
  1. Mesothelioma Stages” (online article) 2007
    Accessed: 3/6/08
  2. Mesothelioma Stages: TNM Staging” (online article) 2007
    Accessed: 3/6/08
  3. Staging” (online article) 2008
    Accessed: 3/6/08
  4. Mesothelioma Treatment Options” (online article) 1/11/07
    Accessed: 3/6/08
  5. Mesothelioma Treatments Non-Traditional Mesothelioma Treatment options” (online article) 2007
    Accessed: 3/6/08
  6. Types of Complementary and Alternative Medicine (CAM)” (online article) 6/8/05
    Accessed: 3/6/08
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    Accessed: 3/6/08
  8. Mesothelioma Diagnosis Questions (online article) 2008
    Accessed: 3/6/08