Stages of Mesothelioma

Staging Of Mesothelioma

You may have heard of the term "staging" or "stages" when it comes to mesothelioma. This simply refers to determining how far the disease has progressed. There are three main factors when it comes to dertermining the progress of the disease: the size of the tumor, how many lymph nodes are affected, and whether the disease has affected any other organs. Staging allows the patient and doctor to determine treatment options. Staging is divided into 3 areas, designated by the capital letters TNM:

T refers to whether the original tumor has exceeded its margins.
N stands for lymph nodes that are affected.
M refers to metastasis to other areas of the body.

Pleural mesothelioma is further divided into overall stages:

Stage I - The cancer is present only on the pleura of the chest wall and the outer lining of the lungs.
Stage II - The cancer has spread into the lining of the lung, the internal lung tissues, or the diaphragm.
Stage III - The cancer has invaded chest lymph nodes, or has not yet invaded lymph nodes but has spread to the mediastinum or the outer layer of the heart.
Stage IV - The cancer is present in adjacent structures, with or without spread to remote areas of the body.

Malignant Mesothelioma Stages In Detail

The TNM staging system for malignant mesothelioma was adopted in 2002. This system utilizes description of the tumor involvement, lymph node involvement, and the presence or not of distant metastasis of the tumor. Staging is then categorized based on the TNM data.

Tx refers to a tumor that cannot be assessed.
T0 is no evidence of primary tumor.
T1 through T4 refer to the extent of tumor invasion in and around the lung structures.
Nx refers to lymph nodes that cannot be assessed.
N0 implies no regional lymph node metastasis.
N1-N3 refers to the anatomical location of lymph node metastasis.
Mx refers to distant metastasis that cannot be assessed.
M0 is no evidence of distant metastasis.
M1 is any distant metastasis present.

Disease stage is then determined as Stage 1A, 1B, Stage II, III, or IV based on the TNM criteria above.

The 3 Classification Systems Used To Stage Mesothelioma And The Stages Involved In Each

The Butchart System is the oldest staging system, the more recent is the TNM system, and the latest system used is the Brigham System. The Butchart System describes Stage 1 as involving the lining of one lung and the diaphragm on the same side, Stage 2 involves invasion into the chest wall, esophagus, heart, or involving both lungs, with possibily lymph nodes in chest being involved. Stage 3 involves the diaphragm extending into the lining of the abdominal cavity or peritoneum, and may effect lymph nodes beyond those in the chest. Stage 4 is the final stages and involves mets or spread of cancer to other organs. The TNM System Stage 1 involves the lining of one lung, the pericardium or diaphragm on the same side with no lymph node involvement. State 2 shows involvement of lymph nodes to the lung effected on the same side. Stage 3 involves chest wall muscle, ribs, heart, esophagus or other organs of the chest on the same side of the primary tumor. Stage 4 involves spread of disease to lymph nodes in the chest on the opposite side of the primary tumor, extends into the lung opposite the primary tumor, or extends directly into the organs of the abdominal cavity or neck. Mets are included in this stage. The Brigham system focuses on the resectability of the mass surgically. Stage 1 is that the tumor is resectable and lymph nodes are not involved. Stage 2 is mass is resectable but lymph nodes are involved. Stage 3 is mass is unresectable and extends into the chest wall, heart, or through the diaphragm, peritoneum, with or without lymph node involvement. Stage 4 occurs when doctors discover mets of distant organs.

No matter the stage when first diagnosed, the prognosis for mesothelioma victims is extremely poor. Without any treatment, mesothelioma is typically fatal within 4 to 13 months of diagnosis. Regardless of therapeutic approach, treated patients can expect a 6 to 18 month median survival rate. Few patients have survived 5 years after diagnosis.