TNM Staging System for Mesothelioma

The Tumor Node Metastasis staging system is the gold standard for staging malignant pleural mesothelioma. The system’s initials relate to certain aspects of mesothelioma tumors.

Tumor Node Metastasis System:
  • T: Tumor size and location
  • N: Nodes (if tumors have spread to the lymph nodes)
  • M: Metastasized (if tumors have spread to distant organs on the other side of the body)

The TNM is the official pleural mesothelioma staging system. Doctors are using a version of the TNM system for peritoneal mesothelioma while researchers work on developing definitions for peritoneal stages. 

The stages of pleural mesothelioma are:
  • Stage 1: Early tumor growth occurs along the mesothelial lining of one lung.
  • Stage 2: Mesothelioma has spread to nearby lymph nodes.
  • Stage 3: Tumors have invaded deeper tissues in nearby organs and distant lymph nodes.
  • Stage 4: Metastasis is present and tumors have formed at distant parts of the body.

Cancer staging is a crucial part of diagnosing mesothelioma that greatly impacts treatment options. People with mesothelioma can learn about how staging affects treatment to make more informed choices. 

Early-stage patients often consider aggressive treatment combinations with surgery. Mid-stage patients may face tough choices about whether they want to pursue more aggressive treatment options. Those diagnosed with late-stage mesothelioma may consider palliative care to extend survival and improve symptoms of mesothelioma.

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How Does Staging Affect Mesothelioma Prognosis?

Doctors also use staging to help inform a patient’s prognosis. Early-stage mesothelioma has a better prognosis and prolonged survival. The extent of disease determines the likelihood of success with the available treatments.

Early-stage mesothelioma patients have better treatment options than late-stage patients. Treatment is more effective in the early stages when patients have fewer tumors. Treatment still improves the prognosis for late-stage patients.

Patients ask us about mesothelioma stages, prognosis and how doctors decide on treatments such as immunotherapy vs. chemotherapy. Surgical patients are very concerned about whether it is ‘worth it’ and quality of life post-surgery, depending on their stage.
Danielle DiPietro
Patient Advocate and VA-Accredited Claims Agent

The typical mesothelioma life expectancy ranges from 22.2 months at stage 1 to 14.9 months at stage 4. Mesothelioma survival rate data is based on cases diagnosed years ago and cannot predict individual survival. Recent advancements in treatment have also helped people at all stages live longer with mesothelioma.

Staging Pleural Mesothelioma

Doctors primarily use biopsy procedures and imaging tests, such as CT scans or X-rays, to stage pleural mesothelioma. Biopsies can detect cancer in lymph nodes. Biopsies can detect cancer in lymph nodes. Imaging scans visualize the size and location of tumors. Sometimes people who undergo surgery learn they have a more advanced stage because mesothelioma cells that imaging scans could not detect are discovered in tissues.

“The way we determine the stage is with a CT or PET scan,” Dr. Jacques Fontaine, director of the Mesothelioma Research and Treatment Center at the Moffitt Cancer Center, shared with The Mesothelioma Center. “If we see the mesothelioma is only in the chest, for example, the best treatment is usually a combination of surgery and chemotherapy.”

Graphic showing stages 1 through 4 of pleural mesothelioma

Staging mesothelioma is important because it helps doctors tailor treatment plans for each patient. Early stages respond better to aggressive treatment. Late-stage treatment focuses on extending survival and improving quality of life. 

“Patients who have stage 1 mesothelioma may be candidates for surgery to have the cancer removed,” Fontaine explained. “Patients who have stage 4 mesothelioma are usually best treated with chemotherapy and ways to make them more comfortable, improve their breathing and take care of their pain.

Stage 1 Mesothelioma

Identifying cancer is difficult at this early stage. Tumors are too small to cause pain or breathing difficulties. Patients with a known history of asbestos exposure undergo screening before experiencing symptoms. In stage 1 mesothelioma, the cancer has not spread past the outer lung lining. All treatment options are most effective at this mesothelioma stage.

Pleural mesothelioma survivor Daniel McCarthy thanks his wife, who is a nurse, for noticing that he sounded short of breath. “She convinced me to see a doctor, and it basically saved my life,” McCarthy told The Mesothelioma Center. Because McCarthy was diagnosed in an earlier stage, surgery was an option for him.

Stage 2 Mesothelioma

Stage 2 mesothelioma spreads locally and develops in nearby lymph nodes. It’s generally rare for symptoms to appear in stage 2, so most diagnoses occur as a result of seeking medical care for another condition. 

Most symptoms appear in stage 3. Doctors treat stage 2 mesothelioma with surgery, chemotherapy and radiation therapy. 

Stage 3 Mesothelioma

Stage 3 mesothelioma tumors spread deeper to nearby tissues, organs and lymph nodes. New symptom developments, such as difficulty breathing or chest pain, often lead to a diagnosis at this cancer stage. 

Doctors typically treat stage 3 mesothelioma with immunotherapy or chemotherapy. Some stage 3 patients are eligible for surgery. Palliative options can help control pain, improve quality of life and extend survival.

Stage 4 Mesothelioma

In stage 4 mesothelioma, also called late-stage mesothelioma, cancer spreads throughout the body cavity where it originated. Unlike other cancers, mesothelioma tends to metastasize locally rather than distantly. It may spread to the chest cavity or the abdominal cavity. In rare cases, mesothelioma spreads to distant parts of the body such as the liver, brain, bones or elsewhere.

Curative treatments are limited. Aggressive surgery for tumor removal is typically not beneficial at this mesothelioma stage. Palliative care options include chemotherapy, Tumor Treating Fields, immunotherapy or radiation therapy. These can reduce symptoms, extend survival and improve quality of life. Clinical trials could offer experimental treatments.