An oncologist, a doctor who specializes in diagnosing and treating cancer, performs a diagnosis of mesothelioma. A proper diagnosis includes an overview of the patient’s medical history with an emphasis on any history of exposure to asbestos. A physical examination that includes a check for lumps, chest and abdominal x-rays as well as lung functioning tests is also performed. A CAT scan or magnetic resonance imaging (MRI) may be used to view images and areas inside the body. A biopsy is then used to confirm the existence of mesothelioma. A biopsy involves the removal of tissue samples for examination. The oncologist determines the method of performing the biopsy based on where the suspected abnormally is located. The extracted sample is then sent to a pathologist who is responsible to examine the tissue under a microscope. Two types of biopsies are performed in the diagnosis of mesothelioma. Thoracoscopy - a biopsy performed in the chest area. Thoracoscopy is procedure where a thin-lighted tube called a thoracoscope is inserted between the ribs of the chest through a small cut in the chest wall. This allows the oncologist to look inside the chest area and obtain tissue samples. Peritoneoscopy - a biopsy performed in the abdominal area. Peritoneoscopy is a procedure where an instrument called a peritoneoscope is inserted through a small cut in the abdominal cavity. If neither of these procedures provides a sufficient amount of tissue to make a definitive diagnosis, more extensive diagnostic surgery may be required. Once a definitive diagnosis is achieved, the oncologist must then determine the stage of the mesothelioma.

Staging Mesothelioma

Staging is the process of testing to determine the extent of the mesothelioma and whether cancerous cells have spread to other parts of the body and to which parts. Staging is necessary to determine the appropriate treatment method. If cancer is only found on the mesothelium membrane in which the tumor originated, the mesothelioma is described as localized. If the cancer has metastasized to other parts of the body, it is described as advanced. Currently, a staging method exits only for pleural mesothelioma since it is the most common, most frequently occurring and most studied form of mesothelioma. Staging is established based on the tumor, lymph node and metastases (TNM) system. Within this system, the disease is categorized based on information relative to the tumor or lymph nodes affected and the metastasis. T stages, N stages and M stages are defined as follows:

T Stages

T1- Cancer has only spread to the pleura covering the lung, with the exception of possibly a few other small spots. T2 – Cancer has spread from the lining of the chest into the outer lining of the lung, the diaphragm, or into the lung itself. T3 – Cancer has spread into the first layer of the chest wall, the fatty part of the mediastinum, a single place in the chest wall, or the outer covering layer of the heart. T4 – Cancer has spread into the chest wall, either muscle or ribs, through the diaphragm, into any organ contained in the mediastinum (esophagus, trachea, thymus, blood vessels), into the spine, across to the pleura on the other side of the chest, through the heart lining or into the heart itself, or into the brachial plexus, which are nerves leading to the arm.

N Stages

N0- There is no spread of cancer to lymph nodes. N1- Cancer has spread to lymph nodes on the same side of the chest as the mesothelioma. N2- Cancer has spread to lymph nodes around the point where the windpipe branches into the left and right bronchi or to lymph nodes in the space behind the chest bone and in front of the heart (mediastinum). Affected lymph nodes are on the same side of the cancerous lung. N3 – Cancer has spread to lymph nodes near the collarbone on either side, to hilar or mediastinal lymph nodes on the side opposite the cancerous lung.

M Stages

M0 – There is no spread of cancer to other organs or areas. M1 - The cancer has spread to other organs or areas, such as the brain or lung that is away from the tumor.

An overall stage for pleural mesothelioma is then established by grouping the T, N and M stages as follows:

Stage I is considered to be a localized form of cancer while all other stages represent various levels of advanced cancer. While there is no established staging for peritoneal mesothelioma, mesothelioma, in general, may be staged into categories as follows:

Category 1 - localized lesion that able to be resected, which means that it may be completely removed.
Category 2 – cancer is contained within the abdominal cavity where a debulking process may occur. Debulking is the process removing as much of the cancer as possible and visible, but not removing all of a tumor.
Category 3 – cancer is contained within the abdominal cavity, but also invading other organs, such as the liver or colon.
Category 4 - cancer extends outside of the abdominal cavity.

Staging is important in determining the severity of disease and the appropriate treatment option. However, other factors must also be taken into consideration. Patients with mesothelioma may experience various challenging complications. The most serious of complications include shortness of breath, chest pains, weight loss, low red blood cell count, high white blood cell count and high levels of LDH. Most patients who suffer all of these complications usually pass within 6 months and few survive for 2 years. Patients who do not suffer any of the stated complications may survive for one year and have a 40% chance of surviving for 2 years.