Mesothelioma Staging

The word "staging" describes the extent of the cancer.

When the stage of your cancer is known, your doctor can choose the most appropriate treatment.

The staging system for mesothelioma is currently under revision, but the staging system currently favored is that endorsed by the American Joint Commission on Cancer (AJCC) and the International Mesothelioma Interest Group (IMIG).

Unfortunately, accurate pre-operative staging of MPM is extremely difficult.

Stage 1a
Tumor involves the outermost layer of pleura (parietal pleura), but does not involve the pleura covering the lung (visceral pleura).

Stage 1b
Tumor involves the parietal as well as the visceral pleura.

Stage 2
Tumor invades into the lung or diaphragm (the thin muscle that separates the chest from the abdomen).

Stage 3
Tumor invades into the fibrous sac around the heart (pericardium), into the chest wall (in one area only) or involves the lymph glands within the chest.

Stage 4
Tumor involves multiple areas of the chest wall, extends across the diaphragm or through the pericardium, involves other organs such as the heart, windpipe or esophagus, or has spread to other organs such as the liver or opposite lung.

Generally, mesothelioma is considered localized if the cancer is found only on the membrane surface where it originated. It is classified as advanced if it has spread beyond the original membrane surface to other parts of the body, such as the lymph nodes, lungs, chest wall, or abdominal organs.

Also known as the International Mesothelioma Interest Group staging system, the TNM system of mesothelioma consists of four stages (American Cancer Society, How is Mesothelioma Staged). In Stage I, the mesothelioma is in the membrane lining the chest (the right or left pleura), and has not spread to the lymph nodes. In stage II, the mesothelioma involves the right or left pleura lining the chest. It has also spread from the lining of the chest into the outer lining of the lung, into the diaphragm, or into the lung.

Staging is a way of describing a cancer, such as where it is located, where it has spread, and if it is affecting the functions of other organs in the body. Doctors use diagnostic tests to determine the cancer's stage, so staging may not be complete until all the tests are finished. Knowing the stage helps the doctor to decide what kind of treatment is best and can help predict a patient's prognosis (chance of recovery). There are different stage descriptions for different types of cancers.

The Brigham staging system was introduced after analyzing the first 52 patients treated with trimodality therapy at the Dana-Farber Cancer Institute/Brigham and Women's Hospital Thoracic Oncology Program. This staging scheme allows four stages and considers resectability and nodal status. Patients with stage I disease have resectable tumors with no affected lymph nodes. Stage II refers to resectable tumors accompanied by positive lymph nodes. Stage III includes tumors that are unresectable due to local extension into mediastinal structures or through the confines of the diaphragm. Stage IV describes metastatic disease.

Brighan staging system, on the other hand, determines whether the Mesothelioma can be surgically removed or not and whether the lymph nodes are affected or not. In stage I Mesothelioma, the lymph nodes are not yet affected and the patient can still recover through surgery. In stage II, surgery can still be executed but some lymph nodes have already been infiltrated by the cancer cells.