Mesothelioma Staging - Stage 4

Stage 4 mesothelioma, the most advanced and final stage of mesothelioma, means that the disease may have spread to the chest wall and to the diaphragm, as well as into the peritoneum, the pleura on the opposite side of the body, to the chest organs, or through the inner layer of the covering of the heart. It has also spread into the lymph nodes on the opposite side of the body, above the collarbones, or to other parts of the body.

Individuals with stage 4 mesothelioma are in a stage of the disease that is considered inoperable. There are a number of treatments and procedures available for stage 4 mesothelioma patients, which may help to alleviate symptoms. Treatments and procedures may include surgery, chemotherapy, radiation, or a combination of the three (multimodality), along with supportive care. Patients with stage 4 mesothelioma may also be eligible to enroll in promising clinical trials. Clinical trials utilize new and innovative therapies that could possibly provide better treatment and outcomes than current treatments.

Although rare, surgery is still a possibility for patients diagnosed with stage 4 mesothelioma. It rare cases, it may be used to remove the affected pleura to help improve breathing. Many researchers also believe that debulking (removal of as much of the tumor as possible) may improve the results of chemotherapy.

Chemotherapy involves several types of anti-cancer drugs either injected directly into the lungs or taken in pill form or intravenously. Chemotherapy drugs disrupt the growth of cancer cells in patients with malignant mesothelioma. Unfortunately, these drugs can damage normal healthy cells as well and can cause unpleasant side effects ranging from hair loss and nausea to anemia and hemorrhaging. Additionally, chemotherapy is not very effective in treating the types of mesothelioma. However, there is a newer chemotherapy regimen, which combines the chemotherapy drugs Alimta and Platinol. 

According to studies, this regimen appears to be the most promising new regimen on the market today. Alimta, when administered in combination with Platinol, is the only drug specifically approved by the U.S. Food and Drug Administration (FDA) for the treatment of inoperable mesothelioma. The combination has a 46% response rate (in studies) and an average survival of 12.1 months. When combined with vitamin supplementation, the average survival was 13.3 months. With Platinol taken alone, the average survival was 9.3 months and with vitamin supplementation, average survival was 10 months.

Other chemotherapy drugs that produced notable response rates include: 5-fluorouracil, Paraplatin, Eloxatin, raltitrexed, Adriamycin, interferon, Navelbine, Taxotere, methotrexate and ranpirnase.

Radiation therapies for stage 4 mesothelioma may include two main types: internal radiation therapy, also known as brachytherapy, and external radiation therapy. Radiation is used to kill cancer cells and shrink the tumor to a manageable size. It relieves pain and reduces symptoms such as shortness of breath. Radiation does not, however, come without consequences. In order to kill all of the cancerous cells, there can be significant damage to the patient.

There are several staging systems currently being used to determine whether patient’s are in the early stages of the disease or the advanced stages. The staging systems include: the TNM Staging System, the Butchart Staging System, and the Brigham Staging System. The TNM staging system is the major staging system. T =  Tumor and refers to the tumor size and how far it has spread to nearby organs; N = Spread to lymph nodes, and M = Metastasis, whether the mesothelioma has spread to other (distant) organs. The TNM Staging System assigns categories and numbers to determine the overall mesothelioma stage. Of course, mesothelioma patients with lower stage numbers have a better likelihood of recovery from the disease or a better chance at long-term survival.

The Butchart System, the oldest of all staging systems, is based on the magnitude of the primary tumor mass. It divides mesothelioma into four stages and it is still currently being used by many specialists in the field. The Brigham Staging System also divides the mesothelioma into four stages and it is based on whether the mesothelioma can treated or removed by surgery. It is also based on whether or not the body’s lymph nodes are involved.

During the staging process, several tests and procedures may be used including chest x-ray, CAT scan (CT scan), magnetic resonance imaging (MRI) and endoscopic ultrasound. Chest x-ray involves an x-ray of all of the bones and organs inside the chest. Also called computed tomography, computerized tomography, or computerized axial tomography, a CAT scan is a procedure that takes pictures from different angles of the abdomen and chest.

Magnetic resonance imaging (MRI), or nuclear magnetic resonance imaging (NMRI), uses a magnet, radio waves, and a computer to create detailed pictures of the abdomen or chest. Endoscopic ultrasound  (EUS) is also called endosonography. It is a procedure that involves the insertion of an endoscope (a thin, tube-like instrument with a light and a lens for viewing) into the body.

Following is a brief description of the other three stages of mesothelioma. Stage 1 mesothelioma, the earliest stage of mesothelioma, affects the outer layer of the pleura around the chest wall. It only affects one side of the chest. The mesothelioma may have grown in the pleural tissue that covers the muscle that separates the thoracic (chest) cavity from the abdomen or the diaphragm (stage 1a), or the disease is in the beginning stages of spreading to the inner pleural layer, but it is still on one side of the chest (stage 1b). There are no lymph nodes containing cancer cells in stage 1 mesothelioma.

Stage 2 mesothelioma means that the mesothelioma has enlarged to form a tumor on the pleural tissue around the lungs or it is spreading into the lung tissue or diaphragm and it has spread to both layers of the pleura on only one side of the body. 

With stage 3 mesothelioma, the disease has spread to the pericardium (the covering of the heart), and the chest wall or the lymph nodes on the same side of the chest.

'Mesothelioma Staging - Stage 4' Resources:
  1. “Mesothelioma Data, Information & Statistics” (online fact sheet) 2007
    Accessed: 3/6/08.
  2. “Stages of Malignant Mesothelioma” (online article) 2/12/08
    Accessed: 3/6/08.
  3. “Malignant Mesothelioma Treatment – Stages of Malignant Mesothelioma” (online article) 8/2/07
    Accessed: 3/6/08.