Written By: Dr. Daniel A. Landau,
Last modified: August 19, 2021

Development of Stage 1 Mesothelioma

In stage 1 mesothelioma, cancer cells have not yet spread through the lymph nodes or far beyond the pleural lining.

Early-stage mesothelioma has a better prognosis than cancer diagnosed in later stages. Surgery, radiation and chemotherapy are more effective at controlling stage 1 disease.


  • Two-year survival rate is between 41% and 46%
  • Often causes no major symptoms
  • Cancer can be removed if the patient is eligible for surgery
  • Combination of surgery, chemotherapy and radiation recommended

Defining Stage 1 Mesothelioma

There are three staging systems for evaluating how far pleural mesothelioma has spread. They use somewhat different definitions for stage 1. The TNM staging system is the most commonly used.

The first stage of pleural mesothelioma is divided into two parts: 1A and 1B.

Stage 1A

In stage 1A, tiny tumors develop in one or both layers of the pleural lining on one side of the chest.

Until recently, stage 1A tumors were separated into T1a and T1b classifications (T stands for tumor). This division indicated whether tumors had developed on one or both layers of the pleural lining.

A 2016 study by the International Association for the Study of Lung Cancer found no survival difference between stage T1a and T1b and this led them to recommend a consolidation. In 2018, the American Joint Committee on Cancer adopted the recommendation.

Stage 1A still includes tumors on one or both layers of the pleura, but does not separate them anymore into T1a and T1b.

Stage 1B

In stage 1B, the tumors start spreading into other tissues next to the pleural lining. This may include the lung tissue under the lining or the chest wall outside it. Cancer could also spread into the muscle under the lungs (the diaphragm) or the area between the lungs (the mediastinum).

Even if mesothelioma has spread to nearby tissues, a stage 1 diagnosis means the cancer has not spread to any lymph nodes or metastasized to distant sites throughout the body.

Peritoneal mesothelioma does not have an official staging system. However, doctors typically think of it as early-stage cancer if it has not spread beyond the lining of the abdomen.

What Are the First Signs of Mesothelioma?

At stage 1, most patients do not have symptoms, or symptoms are so mild that patients do not feel they need medical attention. Mesothelioma is rarely diagnosed at stage 1 for this reason.

When stage 1 cases are discovered, it is often by accident when a doctor performs an X-ray or CT scan while looking for something else. Other stage 1 cases are caught because a patient with a known history of asbestos exposure received cancer screening.

Patients and doctors often mistake mesothelioma symptoms for more common illnesses such as the flu or pneumonia.

Symptoms are caused by tumors that begin to wrap around the affected lung and constrict it. The patient may experience pain, difficulty breathing or a chronic cough as tumors grow. These symptoms typically begin to appear in stage 3 of mesothelioma, but may appear as early as stage 2 for some patients.

These symptoms can also be caused by fluid building between the two layers of the pleural lining, which puts pressure on the lung. This condition is called pleural effusion, and it is a common sign of cancer forming in the lining of the lungs.

In 2020, Case Reports described a pleural mesothelioma patient whose first and only sign of the disease was gastric and colonic polyps discovered on an imaging scan. Testing of the polyps revealed they were metastases of pleural mesothelioma.

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Is There a Cure for Stage 1 Mesothelioma?

There is no cure for mesothelioma, at any stage. While mesothelioma is incurable, early-stage mesothelioma does have more treatment options, and palliative treatments can ease symptoms. The prognosis for stage 1 mesothelioma is favorable compared to mesothelioma diagnosed in later stages.

In the past, most patients have not survived longer than two years after diagnosis. However, some early-stage patients have gone into remission for years after treatment. Remission means the cancer has stopped growing and spreading.

Patients diagnosed early enough to qualify for surgery have the best chance of achieving remission.

Every day, doctors and researchers work to develop treatment strategies in hope of finding a cure. At the same time, many mesothelioma specialists are optimistic they may soon be able to manage this form of cancer as a chronic disease, rather than a terminal illness.

A number of notable mesothelioma survivors — particularly among those with peritoneal mesothelioma — have outlived their prognosis by years thanks to new treatment techniques.

Survival Rate for Stage 1 Mesothelioma

Stage 1 patients have a better prognosis compared to patients diagnosed at other stages of mesothelioma. Approximately 41%-46% of stage 1 mesothelioma patients survive two years, and 18% survive five years.

For comparison, stage 4 patients usually live around one year, and 7% survive five years.

Survival rates are calculated from the statistics for thousands of patients. The rate shows the percentage of patients who were still alive a certain amount of time after they were diagnosed.

This rate explains what happened to a large group of patients in the past. It can only give you a general idea about what to expect from an individual diagnosis in the present.

Life expectancy with stage 1 mesothelioma depends on a number of factors, especially the cancer cell type and the patient’s age and physical fitness level.

Mesothelioma is a rare, complex disease, and every case is different.

How Age Impacts Prognosis for Stage 1 Mesothelioma

Younger patients diagnosed with early-stage mesothelioma often have a better prognosis and more treatment options than patients over 55 years of age.

In general, younger patients have a higher five-year survival rate due to their overall health and greater chance of being surgical candidates. However, research is showing that patients over 70 years of age receive similar benefits if they are candidates for surgeries such as pleurectomy with decortication.

The average age of a mesothelioma patient is 69, and about 8% of male patients ages 65 to 74 live for five years or more. Meanwhile, women in the same age group have a 14.1% five-year survival rate.

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    Stage 1 Mesothelioma Treatment Options

    Surgery is the mainstay of treatment for stage 1 patients. But often, radiation, chemotherapy or a combination of both will be performed around the time of surgery to help improve long-term remission rates. Talk to your doctor to learn how they prefer to sequence therapy because it can vary from center to center.

    Patients with localized cancer have the most treatment options available to them. But it also depends on the patient’s overall health. Patients must be in strong health to handle an aggressive treatment plan.

    Patients who undergo multimodal therapy may live years beyond the average mesothelioma prognosis.


    There are two major surgery options for stage 1 pleural mesothelioma. One removes the diseased tissue around the lung, while the other removes the lung as well.

    Which option is best depends on how far the cancer has spread and how much surgery the patient’s body can handle.


    Pemetrexed (Alimta) and cisplatin are the most common chemotherapy drugs for mesothelioma.

    Doctors may use chemotherapy on its own or in combination with surgery for stage 1 patients. After a patient recovers from surgery, they usually receive chemotherapy. The goal is to kill any remaining cancer cells in their body.

    Radiation Therapy

    Doctors traditionally use radiation therapy after surgery to prevent local recurrence. Applying radiation therapy after surgery might improve survival rates for certain stage 1 patients.

    Clinical Trials and Emerging Therapies

    Many early-stage patients in otherwise good health qualify for mesothelioma clinical trials.

    These voluntary research studies test experimental drugs and therapies not yet approved by the U.S. Food and Drug Administration for mainstream use. Emerging therapies for mesothelioma include immunotherapy, gene therapy and photodynamic therapy.

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