The 4 Stages of Mesothelioma

If you or a loved one struggles to accept a mesothelioma diagnosis, you’re not alone, even if it might feel that way. However, you probably have questions about the four stages of mesothelioma, including what to expect, available treatments, and so forth.

Our legal professionals from The Halpern Law Firm draw upon their 30+ years of experience handling mesothelioma cases to answer your questions, concerns, and issues about this illness.

What Are the 4 Stages of Mesothelioma?

Many people mistakenly think that mesothelioma is a type of lung cancer, but technically that isn’t correct. Lung cancer develops inside the lungs, while mesothelioma causes tumors of the pleural tissue, or pleura, that surrounds the outside of the lungs, diaphragm, and chest cavity. However, both diseases can be caused by inhaling asbestos fibers.

There are different types of mesothelioma, but pleural mesothelioma is the only type with specific stages that describe its progression. Essentially, the four stages of mesothelioma refer to the size, location, and development of the tumors, which directly affect the patient’s outward symptoms.

Stage 1

Patients with early-stage mesothelioma have the best chance of successful treatment for longer survival. In stage one, the tumors begin to form but have not yet reached the outer lung lining. Therefore, the primary course of treatment is surgery to remove the tumors.

Stage 1A: In stage 1A, the tumors begin to develop within the pleural layers of the lung

Stage 1B: In stage 1B, the tumors advance further into the lungs, reaching the chest wall and diaphragm muscle beneath the lungs.

Stage 2

Many patients may not present any symptoms during stage two. During this stage, the tumors spread past the lung lining and penetrate the lymph nodes. However, they’re still small enough that surgical removal is a viable treatment option. Furthermore, the patient may receive radiation therapy and chemotherapy.

Stage 3

Patients in stage three usually have symptoms of chest pain, wheezing, difficulty breathing, and a chronic dry cough. While surgery may be an option, the most common treatment is chemotherapy. Stage three also has two substages:

Stage 3A: In stage 3A, the tumors grow and spread further into lymph nodes, tissues, and organs. Surgery may still be an option for some patients.

Stage 3B: Surgery is less likely for patients in stage 3B, as the tumors are now extensive and have spread deeper into the lymph nodes.

Stage 4

Once mesothelioma progresses to stage four, the chance of long-term survival becomes low because the tumors have spread throughout the body, including the liver, brain, bones, etc. Treatment options are limited but usually include radiation or chemotherapy. In addition, some patients may be eligible for clinical trial options like immunotherapy. For advanced cases, the only treatment option is medication to make the patient more comfortable or relieve symptoms.

TNM Staging System

The most common staging system for mesothelioma is the TNM System, which the Union for International Cancer Control and American Joint Committee on Cancer regulates. The TNM System uses three primary criteria to evaluate the progression of mesothelioma cancer in patients:


The first criterion measures the size of the patient’s main tumor, including its location, if it has spread to other areas in the chest, and whether surgical removal is viable.

Lymph Nodes

The next criterion involves the lymph nodes. Mesothelioma tumors will spread from the chest lining to the lymph nodes after the first stage, so evaluating this area of the body is essential.


The final criterion examines whether the tumors are in other areas of the body (beyond the lungs), such as the liver and bones.

Once the oncologist uses the TNM System to determine the progression, they will combine the results and assign the patient a stage. Then, it becomes easier to decide which type of treatment options are the most likely to be successful.

Call The Halpern Law Firm Today

As you can see, the 4 stages of mesothelioma directly impact a patient’s life expectancy and the type of treatment they can receive. If you or a loved one is suffering from mesothelioma, your case may qualify for compensation. However, it’s important to speak with an experienced lawyer who can provide support and help you navigate the claims process.

David Halpern is committed to helping mesothelioma victims and their families. He is involved in every case meeting and preparing clients, sending out a discovery to defendants, and taking corporate depositions. His discovery often involves site inspections and document inspections at the worksites clients have worked at.

This type of commitment and dedication ensures the companies at fault are held responsible for their actions and has resulted in many millions of dollars recovered for Philadelphia and New Jersey asbestos cancer victims. At The Halpern Law Firm, we’ve helped clients just like you for over 30 years with lung cancer and mesothelioma cases, and we would be happy to help you, too.

Call our team at The Halpern Law Firm today at (800) 505-6000 to schedule a free consultation.

Get in Touch With Our Pennsylvania Mesothelioma Law Firm