What Are the Stages of Mesothelioma?

Mesothelioma Stages

Cancer staging for the stages of mesothelioma helps doctors determine how far cancer has spread, which is crucial for planning the best treatment. This process is used for all types of cancer, including mesothelioma. Staging provides key details about the cancer’s location and progression, helping to guide treatment decisions. Mesothelioma can develop in three areas: the lung lining (pleura), the abdominal lining (peritoneum), or the heart lining (pericardium).

Malignant pleural mesothelioma, being the most common type, is the only one with a formal staging system. For peritoneal and pericardial mesothelioma, formal staging systems do not exist due to their rarity and the challenges in early detection. Understanding mesothelioma staging is essential for making informed decisions about treatment and managing expectations so you can deal with the diagnosis emotionally. This article will explore how staging affects mesothelioma treatment options and prognosis and also explore what you can do next.

What Is the Mesothelioma Staging Process?

Staging is a universal system used by oncologists to describe how far cancer has spread and helps determine the most appropriate treatment. For all cancers, including mesothelioma, staging ranges from 1 (I) to 4 (IV), with lower numbers indicating less spread and higher numbers indicating more extensive spread. The TNM system—Tumor, Nodes, Metastasis—provides further details about the cancer’s growth and spread. While malignant pleural mesothelioma has a formal staging system, other types, like peritoneal and pericardial mesothelioma, rely on estimated stages due to their rarity and challenges in early detection. Understanding staging is crucial for deciding on treatment options and managing prognosis.

Exams and Tests to Stage Mesothelioma

Staging provides a standardized way to describe the characteristics of a cancer, including its location, type, and how far it has spread. Accurate information is important as it determines the best course of treatment to positively impact you or your family.

In the case of mesothelioma, a rare cancer caused by asbestos exposure, staging helps oncologists understand the extent of the disease and develop a personalized treatment plan. Mesothelioma can develop in three different locations: the tissue of the lungs (pleura), abdomen (peritoneum), or heart (pericardium). Each site has its own staging system, with pleural mesothelioma having the most formalized. To accurately stage mesothelioma, a series of tests and examinations are typically required. These may include:

• Physical exam: A doctor will assess the patient’s overall health and look for any signs or symptoms of mesothelioma, such as chest pain, shortness of breath, or weight loss.
  
• Lab tests: Blood tests may be performed to check for anemia, elevated liver enzymes, or other abnormalities that can be associated with mesothelioma.
  
• Imaging tests: These may include X-rays, CT scans, MRIs, or PET scans to visualize the tumor and assess its size, location, and spread.
  
• Biopsies: A biopsy involves taking a sample of tissue from the tumor for examination under a microscope. This is the only way to definitively diagnose mesothelioma.

Understanding the importance of these tests can help patients feel more informed and prepared for their treatment journey.

Four Stages of Mesothelioma – TNM Staging System

As previously mentioned, mesothelioma is a rare cancer caused by asbestos exposure. To effectively treat and manage this disease, doctors use a staging system to determine its extent and progression. This staging system consists of four stages, each representing a different level of cancer development.

TNM Staging for Pleural Mesothelioma

Stage	Description
Stage 1	The tumor is localized to the site of origin. The lymph nodes are unaffected, and there is no metastasis in other parts of the body.
Stage 2	The tumor is localized to one side but extends deeper into the pleura, diaphragm, and/or lung. Nearby lymph nodes may be affected but no distant metastasis.
Stage 3	The tumor extends deeper into the pleura, diaphragm, lung, chest wall, thoracic fascia, heart sac, and/or mediastinal fat. Cancer has spread to same-side lymph nodes with potential metastasis to nearby organs.
Stage 4	The tumor is no longer localized and is not resectable. It may have spread to distant lymph nodes on the other side of the body and other distant organs.

The Brigham and Butchart staging systems are older but still used in some cases. The Brigham system stages based on lymph node spread and resectability, while the Butchart system focuses on tumor location.

TNM staging is a widely used system to classify the extent to which cancer has spread. For pleural mesothelioma, the staging assesses the size of the tumor (T), involvement of nearby lymph nodes (N), and the presence of distant metastasis (M). This system helps doctors determine the severity of the disease and plan appropriate treatment.

Code	Definition	Description
T	Tumor	Describes the size and extent of the primary tumor. Ranges from T1 (small, localized) to T4 (large, invasive).
N	Nodes	Indicates whether cancer has spread to nearby lymph nodes. Ranges from N0 (no spread) to N3 (extensive spread).
M	Metastasis	Shows whether cancer has spread to other parts of the body. Ranges from M0 ( no distant spread) to M1 (distant spread).

Pleural Mesothelioma Stages

Malignant pleural mesothelioma (MPM), cancer in the lining of the lung, is the most common type of mesothelioma (70 to 90 percent of cases) and, as mentioned above, is the only type with a formal staging system. The eighth TNM classification for malignant pleural mesothelioma, developed by the American Joint Committee on Cancer, was published in 2018 and is the current staging system for mesothelioma.

Peritoneal Mesothelioma Stages

Peritoneal mesothelioma, which affects the abdominal lining due to asbestos exposure, accounts for 10 to 30 percent of all mesothelioma cases. Unlike pleural mesothelioma, there is no formal staging system for peritoneal mesothelioma. However, doctors may use general cancer-staging guidelines, such as those from the AJCC’s “AJCC Cancer Staging Manual,” to approximate a stage from 1 to 4.

In addition, the Peritoneal Cancer Index (PCI) is used to evaluate the extent of tumors within the abdominal cavity and determine if the cancer has spread to lymph nodes or other organs. The PCI score ranges from 0 to 39 and helps in deciding eligibility for treatments like cytoreductive surgery and Hyperthermic Intraperitoneal Chemotherapy (HIPEC). Generally, a lower PCI score indicates fewer, smaller tumors and a better prognosis.

Pericardial Mesothelioma Stages

Pericardial mesothelioma, which affects the heart lining and accounts for less than five percent of all mesothelioma cases, lacks a formal staging system due to its rarity and often late diagnosis. Severity is assessed based on the size of the tumor and its resectability. Oncologists may use general cancer-staging guidelines to estimate the stage.

Financial and Legal Assistance for Those with Mesothelioma

While pleural mesothelioma is classified using the TNM system, other types, such as peritoneal and pericardial mesothelioma, do not have formal staging systems. Instead, prognosis and treatment are based on individualized assessments by oncologists. We encourage you to reach out to us for a detailed evaluation of your specific case and to explore available treatment options. Contact us today for a comprehensive case evaluation and personalized guidance.