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Stage 1 Mesothelioma

Stage 1 mesothelioma is the earliest stage of the disease. Patients diagnosed at this stage have the most treatment options and the best prognosis.

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Key Points

  • 1

    Stage 1 mesothelioma is confined to one specific area in the body.

  • 2

    Symptoms are rare or mild, and can be easily confused with other common illnesses.

  • 3

    Treatment is often curative for patients diagnosed at this stage.

  • 4

    Stage 1 mesothelioma patients typically live 1.5 – 3 years after diagnosis.

Stage 1 mesothelioma is the earliest stage of the disease. The cancer is still localized to one part of the body, like the lining of the lungs, and hasn’t spread to any nearby organs or lymph nodes. Patients at this stage rarely experience symptoms, which adds to the difficulty of diagnosing mesothelioma early.

For patients who are able to be diagnosed at this stage, curative treatment options are available. Stage 1 mesothelioma patients have the best prognosis, with an average survival of 21 – 40 months.

Stage 1 Mesothelioma by Type

Because the cancer is localized and tumors are generally smaller at this point, all types of mesothelioma diagnosed at stage 1 have the most curative treatment options available, like surgical resection. With no metastasis and more treatment options, patients have a longer life expectancy.

Stage 1 Pleural Mesothelioma

Mesothelioma specialists use three staging systems to characterize pleural mesothelioma, including the Butchart system, Brigham system and the TNM system. Though all three describe the cancer similarly, many doctors prefer the TNM system because it is updated frequently with the latest mesothelioma information. The TNM system notes the size and location of tumors, any lymph node involvement, and the extent of metastasis.

According to the most recent edition, researchers updated descriptions for stage 1 malignant mesothelioma, which is characterized by two categories.

TNM System Characteristics of Stage 1 Mesothelioma
Stage 1A Mesothelioma
  • Mesothelioma cells are in the pleural lining of the chest wall on one side of the chest
  • Tumors may also impact the pleura lining the lung, diaphragm or mediastinum
  • No spreading to nearby lymph nodes or distant organs
  • May be identified as T1N0M0
Stage 1B Mesothelioma
  • Tumors may have also grown into the first layer of the chest wall, the mediastinum’s fatty tissue, the lung, diaphragm or part of the pericardium
  • The cancer has not spread to nearby lymph nodes or distant organs
  • May be identified as T3N0M0

Stage 1 Peritoneal Mesothelioma

With only about 500 cases each year, research for peritoneal mesothelioma is more limited. As such, doctors haven’t developed specific staging systems for this form of the disease, instead relying on general mesothelioma characteristics or the Peritoneal Cancer Index (PCI). When using PCI, doctors score the size and amount of visible tumors located in 13 distinct regions of the abdomen. The scores are added together, with the totals implying the cancer stage. Researchers have estimated a score of 1 – 10 indicates stage 1 abdominal cancer.

Because pericardial mesothelioma is rare, there is not a widely accepted staging system for the form of cancer.

Symptoms of Stage 1 Mesothelioma

Stage 1 mesothelioma tumors tend to be small and localized, so symptoms are usually absent or very mild. This is why patients are rarely diagnosed at this stage. For patients who do experience symptoms, they can be easily mistaken for common ailments, like a cold or the flu.

Stage 1 Mesothelioma Symptoms
  • Chest pain
  • Persistent cough
  • Shortness of breath
  • Fever
  • Body aches
  • Fatigue

Stage 1 Mesothelioma Life Expectancy

Because the tumors are localized, stage 1 mesothelioma patients have more curative treatment options and a better prognosis. Average life expectancy with such an early diagnosis is 21 – 40 months, though some patients have been able to survive for 5 years or longer.

In addition to an early-stage diagnosis, patients’ prognosis varies depending on the type of mesothelioma, cell type, genetics, overall health, as well as the age and gender of the patient. Many of these factors will also impact the available treatment options

Stage 1 Mesothelioma Treatment

A mesothelioma specialist will develop a mesothelioma treatment plan based on an individual’s specific case. Often, mesothelioma is treated with a combination of treatments, including surgery and chemotherapy. At early mesothelioma stages, curative surgery is still an option and often offers the best chance at extended survival.


Mesothelioma surgery is often only a treatment option for patients diagnosed at stage 1 or stage 2, since the cancer is localized. Many of these surgeries are considered aggressive treatments because they are quite extensive and invasive. Some patients undergo a pleurectomy and decortication (PD), which involves removing the pleural lining of the chest. Other patients undergo an extrapleural pneumonectomy (EPP), which entails the removal of the entire diseased lung along the pleural lining of the chest. Depending on what the cancer cells are invading, part of the diaphragm, chest wall, or pericardium may be removed and reconstructed as well during each of these operations.

These surgeries are often followed with chemotherapy and sometimes radiation therapy to eradicate remaining mesothelioma cells.


Chemotherapy alone doesn’t have a high success rate, with studies showing a 5-year survival rate of about 4%. When combined with surgery, however, researchers have seen better results and some patients have extended survival beyond 5 years. Clinical trials continue to test new combinations of chemotherapies, as well as chemotherapy with other emerging treatments like immunotherapy.

Newer applications of chemotherapy have also seen success, with treatments like hyperthermic intraperitoneal chemotherapy (HIPEC), which is a heated chemotherapy wash, and Pressurized IntraPeritoneal Aerosol Chemotherapy (PIPAC), which uses a pressurized gas application of chemotherapy. HIPEC combined with surgery has helped peritoneal mesothelioma 5-year survival rates improve to well over 50%, with some studies finding survival of 67% or higher. PIPAC, though still in its early phases, has also shown promise in a recent study where patients experienced a median survival of 26.6 months.


Rarely an individual treatment, radiation therapy is sometimes applied following surgery and chemotherapy to kill cancer cells. Patients diagnosed at advanced stages are rarely treated with radiation, as it is a localized treatment. Radiation therapy can also cause some more serious side effects, as the treatment may damage adjacent healthy tissue.

Clinical Trials & Emerging Treatments

Immunotherapy and other emerging treatments have shown promise in treating mesothelioma, even for patients with more advanced disease. While immunotherapies like pembrolizumab (Keytruda) have been the focus of many clinical trials and have shown success in extending life expectancy, researchers are also developing new immunotherapies and combinations in early phase trials.

Personalized cancer vaccines, which are created based on a tumor’s individual genetic makeup, have become a bigger focus of cancer research. Some early clinical trials have found the vaccines could extend mesothelioma life expectancy to over 5 years for some patients. Other new forms of immunotherapy, like immune modulators, are also proving effective in reducing tumor size and improving overall survival. Researchers hope to see some forms of immunotherapy become FDA-approved for mesothelioma soon to extend survival benefits to more patients.