There are four stages of mesothelioma. Doctors use these four stages to determine how much cancer has progressed and the best course of treatment for its present status.
Stage 1 of mesothelioma has relatively the best prognosis, while stage 4, which is the end-stage, has the shortest average life expectancy.
Symptoms are hardly noticed in the early stages and begin to worsen in stage 3 and are worst in stage 4.
Stages of mesothelioma inform about the status of the mesothelioma cancer and whether there is metastasis. This is determined through diagnostic procedures.
It is the staging of mesothelioma that helps the cancer specialist to determine the course of treatment and gives an idea about the prognosis of the disease.
This is a rare cancer and since pleural mesothelioma is more common among the types of mesothelioma, staging parameters are set for pleural mesothelioma only and not for peritoneal and pericardial mesothelioma.
The cancer staging system, therefore, has been officially adopted for pleural mesothelioma only.
Because pericardial mesothelioma is extremely rare, (less than 150 cases of this type have been detected so far), there is no staging system for this type of mesothelioma.
Similarly, since there have been less than 100 cases of testicular mesothelioma, no staging system for this variant has been defined.
For peritoneal mesothelioma, doctors use the peritoneal cancer index (PCI) to determine a score based on the size of the tumor in predetermined different regions in the abdomen. According to a 2020 study, PCI is very precise in predicting the prognosis of the patient during and after treatment. This helps doctors make clinical decisions.
Staging of mesothelioma is done by two systems and each has its own parameters.
The Butchart system of staging pleural mesothelioma
The Butchart staging system is the oldest method of staging pleural mesothelioma
Dr. Eric Butchart developed the Butchart staging system for pleural patients in the late 1970s to help doctors determine the line of treatment.
It helped classify the early and late stages of this disease so that aggressive surgery and chemotherapy could be adopted for early-stage patients.
For example, patients in the early stages I and II receive curative treatment while those in stages III and IV receive supportive treatment (Palliative care).
This staging system is based on locating the place of the tumor and does not account for the size of the tumor.
Though the Butchart system is now obsolete, it helped in the development of the modern staging systems that are in use today.
Mesothelioma stages according to the Butchart system
Stage 1. In this stage, mesothelioma is present only on one side and there is the involvement of the pleura without any invasion into the chest wall.
Stage 2. There is an invasion of the mesothelioma into the chest wall, along with the involvement of the esophagus and the heart, and possibly the pleura on the other side. There may be a spread of cancer into the lymph nodes in the chest.
Stage 3. There is a spread of the pleural mesothelioma into the peritoneum in the abdomen. The lymph nodes in the abdomen may also be involved.
Stage 4. There is metastasis (spread) of mesothelioma through the bloodstream to other organs.
The TNM system of staging pleural mesothelioma
Terminology
T stands for the extent of the primary tumor,
N stands for the absence, presence, or extent of regional lymph node metastasis,
M stands for the absence or presence of metastasis (spread of cancer).
As the size of the untreated tumor increases, regional lymph node involvement and distant metastases become more frequent.
These three important events in cancer growth that are used in clinical examinations to finalize a definitive therapy:
tumor growth
spread to regional lymph nodes, and
distant metastases
TNM staging of cancer is a recently developed staging system, which is usually used to stage solid malignant tumors. Most tumors are classified by this system but some like brain tumors are not.
TNM staging of cancer was developed by a non-governmental body called UICC or International Union Against Cancer with the purpose to bring about a global consensus to stage cancers and access their spread.
This purpose has been achieved and TNM is globally used. This also helped to bring about a coordinated global effort in cancer research. The UICC cancer staging has the same definitions as the AJCC cancer staging (American Joint Committee on Cancer).
TNM staging criteria
The TNM system classifies mesothelioma into four stages. Stages 1 and 2 can be referred to as the early stages and stages 3 and 4 as the late stages of mesothelioma.
Stage 1 Mesothelioma
Stage 1 mesothelioma is considered an early stage of mesothelioma. In this stage, the cancer cells remain localized and have not spread.
There is the involvement of pleura only on one side of the chest. There may be some spread into the lungs but the lymph nodes are not involved.
There are no symptoms in this early stage and the disease is often detected accidentally.
Prognosis. Among all sages, stage 1 mesothelioma has a better prognosis than the later stages because the doctors can use the most aggressive surgical treatment options for a better prognosis.
Survival rate. The 2-year survival rate for stage 1 is about 41%-46% and 18% for five years.
Stage 2 Mesothelioma
In stage 2, mesothelioma cancer has spread to the neighboring organs and tissues without any distant spread.
There is the involvement of the lymph nodes near the lung on the same side of the chest. There may also be involvement of the lung, pericardium, and diaphragm on the same side.
The survival rate for stage 2mesothelioma:
A 2-year survival rate for stage 2 is 39%.
The 5-year survival rate is 9%.
The average time of survival for stage 2 pleural mesothelioma is 19 months, which is only three months more than for stage 3 (16 months for stage 3).
Stage 2 prognosis can still be favorable because of the many treatment options available to extend life expectancy.
In stage 3, the mesothelioma has spread into the lymph nodes on the same side of the chest wall. There is the involvement of the chest wall including the muscles and the ribs. The nearby organs such as the heart and the esophagus may also be involved.
Symptoms of stage 3 include:
Shortness of breath
Pain in the chest or the upper abdomen
Chronic dry cough
Fatigue
Fever
Build up fluid
Loss of weight
The prognosis for stage 3 mesothelioma is poor. Patients diagnosed with this late 3rd stage have an average survival of 18 months.
Stage 4 Mesothelioma
Stage 4 is the final stage of mesothelioma and is terminal.
In this stage, the mesothelioma has spread into the lymph nodes, the pleura, and the lungs on the opposite side of the chest. There may be an invasion into the neck or the organs in the abdomen. In this last stage of mesothelioma, there is metastasis to the distant organs.
Symptoms of this last stage may include:
Shortness of breath
Chronic coughing, which is painful
Pain and tightness in the chest
Severe weight loss
The average life expectancy for this advanced stage 4 mesothelioma is less than 12 months.
In this late stage, cancer can cause multi-organ failure, a weak immune system, malnutrition, and wasting, and can ultimately result in a coma.
Most patients die from mesothelioma in stage 4
Staging parameters
Below is the eighth edition of the TNM staging system for malignant pleural mesothelioma, published in 2018
An ‘X’ suffixed after T or N or M simply means cancer has yet to be evaluated and therefore it has not been staged yet.
T – Tumor: 1 to 4 are suffixed after ‘T’ to indicate the size of the tumor.
TX: primary tumor cannot be assessed
T0 (zero): no evidence of primary tumor
Tis: carcinoma in situ
T1 will mean a smaller-sized tumor while
T4 will indicate a larger-sized tumor
N – Node: Similarly, 0 to 3 are suffixed after ‘N’ to indicate how far the malignancy has spread to the lymph nodes.
N0 will indicate that there has been no metastasis of the malignancy to the lymph node.
N1 will mean spread to the local regional lymph node.
N3 will mean more involvement in the distal and more numerous lymph nodes.
N2 gives the metastasis involvement between N1 and N3.
M – Metastasis: The numbers 0 and 1 are used after M to indicate metastasis to other distant organs.
M0 means no metastasis and
M1 will indicate that the malignancy has spread from the primary site to distant organs. This is the final stage of cancer.
FAQs
What is the general survival for all stages of mesothelioma?
45% of mesothelioma cases survive their mesothelioma for one year or more after diagnosis. Furthermore, more than 5% survive their mesothelioma for 5 years or more after diagnosis.
Has anyone survived mesothelioma?
Many mesothelioma patients have survived the disease and outlived their initial prognosis estimate with the use of established and emerging treatments.
Is mesothelioma curable if caught early?
Surgeons surgically remove the mesothelioma when it’s diagnosed at an early stage. In rare cases, especially when detected very early, this may even cure cancer.
However, most of the time, it isn’t possible to remove all the cancer because early on there are no symptoms. They come on in the later stages to be diagnosed when the disease is beyond complete cure.
Surgery may help to reduce the signs and symptoms and give symptomatic relief caused by mesothelioma spreading in your body.
How fast does mesothelioma progress?
Mesothelioma is extremely slow in setting in. It may take 20 to 60 years or more to develop after exposure to its causative agent, asbestos.
However, once it develops in the body, it tends to spread (metastasize) fairly quickly. Because of this, many experts classify it as an aggressive form of cancer.
How long can you live with untreated mesothelioma?
The mesothelioma life expectancy for an untreated late-stage patient is approximately six to eight months.
Early-diagnosed patients may live one to two years without treatment. Several factors influence the survival time such as the stage, treatment, cell type, and the patient’s overall health status.
Where does mesothelioma spread?
It’s in the last stage that mesothelioma spreads to distant sites in the body. Generally, mesothelioma most often metastasizes to the:
Liver
Kidneys
Spleen
Adrenal glands
Pleural mesothelioma spreads to:
Liver (55.9%)
Adrenal glands (31.3%)
Kidneys (30.1%)
The opposite lung (26.8%)
The most frequent sites of peritoneal metastases include:
Liver
Visceral peritoneal lining
Abdominal lymph nodes
The local spread of pericardial mesothelioma usually occurs in the regional lymph nodes, pleura, lungs, kidneys, and mediastinum.
