pleural mesothelioma stages

The stage of a mesothelioma tumor describes how far it’s spread from where it first appeared in the protective lining of the lungs, abdomen, or heart. The spread of mesothelioma is known as metastasis. The farther mesothelioma has spread, the later doctors stage the disease.

Doctors use imaging tests and biopsies to determine your cancer stage. The results of your diagnosis help them decide which treatments fit your needs, and which will have the most positive impact on your prognosis.

Stage 1: There’s no spread to lymph nodes and the cancer is localized to one side of the body. This is the earliest stage. Stage 1 patients have the most treatment options. Learn More >

Stage 2: Mesothelioma is still localized to one side of the body but there are signs of metastasis to nearby lymph nodes. Aggressive treatment options are still an option. Learn More >

Stage 3: The first significant signs of metastasis have occurred. Mesothelioma has spread to lymph nodes and surrounding organs. Surgical options become limited

Stage 4: Mesothelioma has spread to the other side of the body. Treatment options for stage 4 patients primarily involves relieving symptoms.

Pleural Mesothelioma Stages

Doctors use 4 stages to describe the spread, or metastasis, of pleural mesothelioma. Each stage details how far the tumor has spread from where it first appeared in the pleura, the protective lining of the lungs. Your doctor may also refer to the cancer stage of mesothelioma as early or advanced. Early–stage mesothelioma includes stages 1 and 2, while advanced–stage includes stages 3 and 4.

Stage 1 Pleural Mesothelioma

The growth of stage 1 pleural mesothelioma is limited to the lining of one lung. During stage 1, the tumor can also spread from the outer lining of the lung (closer to the wall of your chest) to the inner lining (closer to the lung itself).

Patients diagnosed with stage 1 mesothelioma have the most favorable prognosis compared to more advanced stages of the disease. Stage 1 tumors are more responsive to curative treatment — like surgery, chemotherapy, or radiation therapy — because the tumor is limited to the lining of one lung and easier for doctors to remove.

Stage 2 Pleural Mesothelioma

Like stage 1, most of the growth of a stage 2 tumor still occurs in the lining of one lung. At this point, however, the cancer cells may have spread to the walls of the patient’s chest, diaphragm, nearby lymph nodes, or to the lung itself.

Patients diagnosed with stage 2 pleural mesothelioma have a similar prognosis to patients with stage 1. Stage 2 patients are still eligible for curative treatments that can extend life expectancy.

Stage 3 Pleural Mesothelioma

At stage 3, a tumor has spread throughout one side of the body, and has invaded at least one—or all—of the following: one lung, the diaphragm, nearby lymph nodes, and the protective lining of the heart.

The prognosis of patients diagnosed with stage 3 mesothelioma is closely linked to age and general health. Those who are healthy, and can withstand surgery, may be eligible for treatments that can extend life expectancy well past the average.

Stage 4 Pleural Mesothelioma

The growth of a stage 4 mesothelioma tumor has spread far beyond the lining of one lung. At this stage, cancer cells and secondary tumors may exist in larger sections of the chest wall, diaphragm, lining of the heart, and lymph nodes located far from the lining of the lung.

Patients diagnosed with stage 4 mesothelioma have an average life expectancy shorter than 12 months. Stage 4 patients may not be eligible for traditional curative treatment options like surgery. Patients do, however, have other options. Palliative treatments ease pain caused by the disease and have shown prognostic benefits in some cases.

Patients can also speak with their doctors about new treatments that researchers are testing in clinical trials. Some experimental therapies currently in clinical trials may become standards treatments, some of which may lead to a cure in the future.

Peritoneal and Pericardial Mesothelioma Staging

Doctors don’t usually use stages to describe the spread of peritoneal or pericardial mesothelioma. Both are rare relative to pleural mesothelioma, which accounts for 75 percent of all cases.

Doctors don’t see enough cases of peritoneal or pericardial mesothelioma to accurately describe them using stages.

Patients with peritoneal or pericardial mesothelioma are generally described as having localized or advanced mesothelioma. An experienced doctor can still assess how far the mesothelioma has spread and which treatments will work best to improve prognosis.

Metastatic Symptoms

Symptoms caused by the spread of mesothelioma are metastatic. As a tumor grows, you’ll feel more symptoms, and they’ll happen more often. Doctors divide metastatic symptoms into two general catergories: early–stage and advanced–stage. Generally speaking, early–stage symptoms cover symptoms caused by stage 1 and stage 2 mesothelioma while advanced–stage involves stages 3 and 4.

In the early stages of metastasis, symptoms of pleural mesothelioma will feel like those caused by other illnesses of the lungs, such as pneumonia or asthma. If you’re diagnosed with early-stage mesothelioma, you may feel or experience:

  • Difficulty breathing
  • Persistent coughing
  • Fatigue
  • Chest pain
  • Fever
  • Weight loss


Symptoms caused by advanced–stage mesothelioma happen more often and are more specific than those caused by early-stage mesothelioma. If you have advanced–stage mesothelioma, you may feel or experience:

  • Hemoptysis, or the coughing up of blood
  • Dysphagia, or difficulty swallowing
  • Increased fatigue
  • Pleural effusions
  • Fever
  • Night sweats


Staging Mesothelioma

Doctors use diagnostic imaging tests to visually confirm how far mesothelioma has spread. Each type of scan provides them with visual information on the growth and spread of a tumor; information they use to determine the cancer stage of the mesothelioma.

CT Scan: A computed tomography (CT) scan generates several x-ray images doctors put together to make a single 3D image of the chest or stomach. Doctors use CT scans to determine if a tumor has spread to the chest wall or diaphragm.

MRI Scan: Doctors use a magnetic resonance imaging (MRI) scan to find out if mesothelioma has spread from the lining of the lungs, the pleura, to the chest wall, lining of the heart, or nearby organs.

Positron Emission Tomography (PET) Scan: A PET scan is the best method to determine if mesothelioma has spread to other parts of the body. Doctors can even use it to find out if a tumor has spread to lymph nodes that are far from where the mesothelioma first appeared.

Staging Systems for Mesothelioma

Doctors use three staging-systems to describe the spread of mesothelioma. These systems weren’t specifically made for the disease, and are more often used for more common lung cancers. Nevertheless, they help doctors determine how far a tumor has spread, and how possible certain treatment options are. Each system focuses on a different aspect of metastasis, but they all divide it into 4 stages.


The American Joint Committee on Cancer (AJCC) staging system emphasizes three main factors regarding the advancement and spread of pleural mesothelioma.

  • T: Refers to the growth of the primary tumor.
  • N: Refers to the extent the tumor has spread to nearby lymph nodes.
  • M: Refers to the tumor’s spread to other organs.


The TNM system assigns numbers to each factor to describe metastasis in more detail.

After they categorize a tumor according to each individual group —T, N, and M— doctors assign it an overall stage grouping ranging from 1 to 4. They assign the stage grouping by combining the tumor’s T, N, and M values. A lower stage grouping number means that the tumor hasn’t spread far.

Brigham System

Doctors use the Brigham system to describe how the spread of a tumor affects their ability to surgically remove it. The Brigham system divides pleural mesothelioma into four stages:

  • Stage 1: The tumor has not spread to the lymph nodes and can be removed via surgery.
  • Stage 2: The tumor is mostly confined to the lining of the lung, but has spread to nearby lymph nodes. It is still possible to remove via surgery.
  • Stage 3: The tumor has spread to nearby organs and body structures, such as the pericardium, chest wall, peritoneum, and diaphragm. Surgery is no longer an option.
  • Stage 4: The tumor has spread to areas and organs far outside where the tumor first appeared. Surgery is no longer an option.

Butchart System

The oldest and most common staging method, doctors use the Butchart system to describe the location of the main tumor, rather than how large it is or how far it has spread.

  • Stage 1: The tumor is in the lining of one lung, and may have spread to the lining of the heart or diaphragm. In the Butchart system, this is the stage where doctors can most effectively remove the tumor.
  • Stage 2: The tumor has spread to the chest wall, and may have grown into the inner part of the lung’s lining. At this stage, it’s also possible that mesothelioma cells are present in the esophagus, heart, and lymph nodes surrounding the chest.
  • Stage 3: The tumor has spread from the lining of the lung to the diaphragm or lining of the abdomen. Mesothelioma cells may have spread into lymph nodes far from the main tumor. At this stage, curative surgery is no longer a good option. Doctors may use palliative treatment may as the main form of treatment.
  • Stage 4: Cancer cells have spread through the bloodstream to areas far from the main tumor. Palliative treatments are now the only available course of treatment.

About Mesothelioma

Firstly it is important to understand that cancer is not a single illness, there are many different types and mesothelioma is just one type.

Our bodies are made of tiny building blocks called cells, cancer is a disease of these cells. Cells from different parts of the body look and work differently and millions of new cells are made everyday to replace those lost through old age or wear and tear.

Throughout the body new cells are produced when existing cells divide into two and there is normally a perfect balance between those that are dying and those that are dividing. This vital balance is controlled by a very complicated process, if control of this process is lost it can lead to too many cells being produced which results in a tumour.

Most tumours are not cancerous (sometimes described as benign) and they remain in the area where they first developed. A wart is a common example.

The development of cancer involves a change in the quality of the cells as well an increase in the quantity. They become more aggressive, destructive and independent of normal cells. They are able to invade surrounding tissues, glands and blood vessels and thus spread away from where they started to divide and grow. When the cancer cells reach a new site they may go on dividing and form a new tumour, this is often referred to as a secondary or metastasis.

What is mesothelioma?

Illustrated image of Lungs and Pleura

Illustrated image of Lungs and Pleura © Mesothelioma UK

In the UK about 2500 people a year are diagnosed with mesothelioma. It is also known as ‘diffuse’ or ‘malignant’ mesothelioma. Mesothelioma is a form of cancer that affects the mesothelium. The mesothelium is a thin membrane that lines the inner surface of:

  1. The chest wall, where it is known as the pleura
  2. The abdomen where it is known as the peritoneum
  3. The testicles

The mesothelium also surrounds organs within these cavities for example the heart, lungs and intestines. It is far more common to have mesothelioma in the chest than in the abdomen. There is approximately one case of peritoneal mesothelioma to every 12 cases of pleural mesothelioma.

Mesothelioma is more common in men than in women and nearly half of the people diagnosed with the disease are over 75 years old.

Pleural mesothelioma

The pleural lining has two layers: the visceral (inner) layer is next to the lung and the parietal (outer) layer lines the chest wall. The pleura produces fluid that lubricates the space between the two layers, this allows the two layers to slide comfortably over each other as we breathe in and out.

Illustrated image of Lungs and Pleura

Illustrated image of Lungs and Pleura © Copyright Mesothelioma UK

Pleural mesothelioma causes the pleura to thicken. This thickening of the pleura might begin to press onto the lungs or attach itself to the inside of the chest wall. In either case the expansion of the lung becomes progressively restricted by the tumour. Fluid, sometimes several litres, can collect between the two layers of the pleura; this affects the lungs ability to expand and causes the person to feel breathless. This is known as a pleural effusion.

Click to download the PDF leaflet, ‘What is mesothelioma?’

Symptoms of pleural mesothelioma

  • shortness of breath
  • chest pain
  • cough
  • sweating
  • loss of appetite
  • weight loss
  • fatigue and lethargy


Peritoneal mesothelioma

Illustrated image of Abdominal Cavity and peritoneum

Illustrated image of Abdominal Cavity and peritoneum © Mesothelioma UK

The peritoneum also has two layers the inner (visceral) layer which is next to the abdominal organs and the outer (parietal) layer which lines the abdominal wall.

Peritoneal mesothelioma causes the peritoneum to thicken and fluid to collect in the abdomen. This collection of fluid is called ascites and causes the abdomen to swell.

Because pleural mesothelioma is more common and often spreads to the peritoneal cavity, it is sometimes necessary to determine if pleural mesothelioma is the primary cancer.

Symptoms of peritoneal mesothelioma

  • abdominal pain
  • abdominal swelling or feeling bloated
  • constipation or diarrhoea
  • fatigue
  • loss of appetite
  • weight loss

The most common symptoms for pleural and peritoneal mesothelioma are listed here, but there may be others. You can find out more about treatments for these symptoms in the Controlling Symptoms section.

Referral for peritoneal mesothelioma MDT

A national peritoneal mesothelioma multi-disciplinary team (MDT) is coordinated monthly at Basingstoke Hospital. Please contact Mesothelioma UK for information about how cases can be referred and reviewed.