The
Four Stages of Mesothelioma
Doctors can use one of three systems for mesothelioma
staging: TNM, Brigham and Butchart. These systems are used primarily for
pleural mesothelioma, the most common type. There are currently no formal staging
systems for the other types.
The
Three Mesothelioma Staging Systems
1. TNM
2. Brigham
3. Butchart
The TNM system is the most internationally accepted by
mesothelioma specialists, although some doctors believe none is accurate enough
yet.
If you are diagnosed with mesothelioma, you should seek a
second opinion to make sure your cancer has been staged correctly. Many
oncologists do not have experience with asbestos-related cancers. Always find a
doctor who does.
Stage
1
Initially, tumor growth is localized to a single area.
The life expectancy associated with stage 1 mesothelioma is significantly
better than those of later stages, but it is difficult to catch the cancer this
early because people with this stage do not usually experience symptoms.
Major surgery to remove the tumor is considered the first
line of treatment, and doctors usually recommend an aggressive multimodal
approach including chemotherapy, radiation therapy or immunotherapy.
Median life expectancy at stage 1 is 21 months with
surgery.
Stage
2
Stage 2 symptoms are vague and mild, and patients and
doctors often mistake them for signs of other illnesses such as the flu.
Patients with peritoneal mesothelioma may lose weight and yet feel bloated. The
available treatment options are generally the same as for stage 1 mesothelioma.
Median life expectancy at stage 2 is 19 months with
surgery.
Stage
3
Once the cancer progresses to stage 3, it may have spread
to several tissues, organs and lymph nodes in the same region of the body where
it originally formed.
Pleural mesothelioma patients may suffer from difficulty
breathing and intense chest pain even when resting. Peritoneal mesothelioma
usually involves abdominal pain and digestive problems. Discomfort may be felt
in other parts of the body as well.
Some stage 3 cancer patients are ineligible for surgery
and other aggressive treatments. At that point, doctors offer palliative
options.
Median life expectancy at stage 3 is 16 months with
surgery.
Stage
4
By stage 4, cancer has spread throughout the body via the
bloodstream (a process called metastasis) and could be present in the liver,
brain, bones or elsewhere. Patients may experience extreme difficulty breathing
and swallowing, digestive problems and severe pain.
For stage 4 patients, doctors fall back on palliative
treatments designed to ease pain and control other symptoms.
Median life expectancy at stage 4 is 12 months or less
with surgery.
TNM
Staging System
Also called the IMIG Staging System, this is the most
widely used system for pleural mesothelioma. Doctors sometimes use it for other
types of mesothelioma as well.
The abbreviation TNM signifies three different parts of a
diagnosis. Doctors add a number after each letter to describe how far the
cancer has advanced. As tumor size increases and the cancer invades more
structures, the number increases.
• T
describes tumor size and location, ranging from T0 to T4.
• N
describes whether lymph nodes are affected, ranging from N0 to N3.
• M
describes whether the tumors have metastasized (spread through the bloodstream
to other parts of the body), ranging from M0 to M1.
Doctors use the TNM framework to stage many different
types of cancer. In 1995, the International Mesothelioma Interest Group (IMIG)
modified this system specifically for asbestos-related cancers because of the
lack of a universally accepted staging system.
After evaluating a case, doctors assign a value to each
part of the TNM system. Next, they use this information to give the cancer a
stage. For example, TNM staging guidelines say a T1N1M0 mesothelioma is a stage
3 cancer.
Stage
1
T1, N0, M0: Mesothelioma has developed in the pleura
lining one side of the chest wall and may affect the lining near the breathing
muscle (diaphragm) or the area between the lungs (mediastinum).
Stage
2
T2, N0, M0: Mesothelioma has grown in the pleura lining
one side of the chest wall and the lining near the diaphragm, the mediastinum
and the lung, and it has also grown into the diaphragm or the lung itself.
Stage
3
T3, N0–N2, M0: Mesothelioma has spread from the pleura
into part of the chest wall, the outer layer of the heart sac or the fatty
tissue in the mediastinum.
T1–T2, N1–N2, M0: The primary tumor mass has not spread
far beyond the pleura, but mesothelioma cells have spread to lymph nodes near
the tumor.
Stage
4
T4: Mesothelioma has penetrated into the abdominal
lining, the spine, the deep layers of the chest wall, the pleura on the other
side of the chest, or any vital organ between the lungs.
N3: Mesothelioma cells have spread to lymph nodes far
from the primary tumor mass.
M1: Mesothelioma tumors have developed in distant parts
of the body.