Mesothelioma Stage 1
When doctors stage mesothelioma, they use one of two staging systems.
The Butchart System
The oldest, known as the Butchart System, was developed in1976 by Dr. Eric Butchart, a British cardiothoracic surgeon. Some oncologists and thoracic surgeons still use this system because they believe it to be the most accurate way to measure the progression of the disease. A description of Dr. Butchart’s classification system appears in the article he authored titled “Contemporary Management of Malignant Pleural Mesothelioma”, published December 1999 in The Oncologist.
The TNM System
The other system, known as the TNM System, is currently the most widely used. It was originally developed by French physician Pierre Denoix from 1943 to 1952. In 1990, The International Union Against Cancer (UICC) developed a version of the TNM system to be used for lung cancer staging based on the TNM methodology used for other tumors. In 1995, this system was adapted by the International Mesothelioma Interest Group (IMIG) to give precise descriptions of tumor involvement in various areas of the body.
The IMIG staging system was adopted by the American Joint Committee on Cancer (AJCC) and the UICC in 2002 so that there would be uniformity. Today, the version of the TNM classification that is in practice follows the rules of classification and staging that appear in The Seventh Edition AJCC Cancer Staging Manual, which was released in 2009 with revisions implemented in January, 2010.
Stage I – The Butchart System
The tumor has not gone beyond the parietal pleura, which is the part of the pleura that connects to the chest wall. Also, it has not spread to regional lymph nodes. The tumor is considered to be operable; and survival rates are good for patients at this stage that have negative surgical margins and no lymph node involvement. A surgical margin refers to an evaluation of a tumor that has been removed to see if normal tissue has been removed with it. If there is normal tissue that means the entire visible tumor has been removed. Keep in mind that microscopic cells may have been left behind, resulting in the need for chemotherapy/radiation. However, it is highly likely that these additional therapies will remove all of the remaining cancer cells.
Stage I – The TNM System
The TNM system is based on the evaluation of three components:
- T- The extent of the primary tumor
- N- Whether or not the tumor has spread (metastasized) into the regional lymph nodes and how extensively it has spread
- M – Whether or not there is distant metastasis
Numbers are used in conjunction with each letter to indicate the extent
of the disease.
In stage I, the tumor is small and remains local. It has not metastasized to any lymph nodes or any other parts of the body.
Stage 1 is subcategorized into 1A and 1B:
- Stage 1A – the tumor size is up to 3cm
- Stage 1B – the tumor size is between 3 to 5cm
The tumor is considered operable and the prognosis is good with the addition of chemotherapy/radiation.