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Stage 1 Mesothelioma

Stage 1 mesothelioma is the earliest stage of mesothelioma and has the best prognosis since tumors have not spread much and the cancer is easier to treat.

Medically reviewed for accuracy by

Dr. Stephen Williams

Precision Oncology Scientist

AI Summary of Stage 1 Mesothelioma

Stage 1 mesothelioma represents the earliest phase of this cancer, and it typically offers the best prognosis because the tumors have not yet spread to other parts of the body. This early stage is characterized by localized tumors, meaning the cancer is confined to the lining of the lungs or abdomen, and has not involved nearby lymph nodes or distant organs. The tumors are generally small, which makes them more accessible for treatments such as surgery, radiation, and chemotherapy. Patients with stage 1 mesothelioma often have a better chance of long-term survival, especially because most treatment options are available at this stage along with the potential for more aggressive local treatments.

Important Facts About Stage 1 Mesothelioma

Stage 1 is the most hopeful stage of mesothelioma cancer and has the best life expectancy.
All treatment options are available to patients with stage 1 mesothelioma.
Diagnosing stage 1 mesothelioma is difficult due to the lack of symptoms.
The average survival time for stage 1 mesothelioma is 20 months and often much longer with surgery.

Overview of Stage 1 Mesothelioma

Stage 1 mesothelioma is the first stage of mesothelioma. It is classified as early stage mesothelioma, which is crucial because it has not yet spread to distant tissues or lymph nodes, making it treatable in a number of methods.

Where Stage 1 Mesothelioma Begins

Diagram illustrating stage 1 pleural mesothelioma, highlighting the pleura between the lung and chest wall.

Diagram illustrating Stage 1 peritoneal mesothelioma affecting the peritoneum and a small part of the abdomen

Stage 1 mesothelioma is in:

The pleura (the thin lining between the lung and chest wall) for pleural mesothelioma

The peritoneum (a thin membrane lining the abdominal cavity) and a relatively small portion of the abdomen for peritoneal mesothelioma

Pleural mesothelioma (lining of the lungs) is the most common type of mesothelioma. Peritoneal mesothelioma (lining of the abdominal cavity) is the next most common type. The two other types of mesothelioma – pericardial mesothelioma and testicular mesothelioma – are so rare that staging is difficult to determine due to limited cases.

Key Characteristics of Stage 1 Mesothelioma

Localized tumors – At this stage, tumors are localized – either in the pleura or peritoneum – without metastasis to nearby lymph nodes or distant organs. This significantly enhances the potential for surgical resection and other local treatments.

Tumor size – In stage 1, tumors are small in size, which is a critical factor in deciding a plan for treatment. Smaller tumors are easier to target with surgery, radiation therapy and chemotherapy.

No lymph node involvement – There is no spread to regional lymph nodes in stage 1 mesothelioma, a key factor that distinguishes it from more advanced stages of the disease. This lack of lymphatic spread allows for more aggressive treatment.

Stage 1 pleural mesothelioma is subdivided into two subcategories:

Stage 1A – Tumors are confined to the outer layer of the pleura, specifically the parietal pleura, which lines the chest wall. At this stage, the tumor remains in a localized area, making surgical options viable.
Stage 1B – Tumors are found on both the outer and inner layers of the pleura, the parietal and visceral pleura. Though these tumors have expanded into a slightly larger area, they have not yet spread to other regions of the body. Stage 1 is separated into 1A and 1B. Stage 1A involves tumors on the outer wall of the pleura (the parietal pleura). Stage 1B involves tumors on the outer wall and the inner wall (the visceral pleura).

Stage 1 mesothelioma patients have the best prognosis. This is because most treatment options are available for patients.

Diagnosing Stage 1 Mesothelioma

Diagnosing stage 1 mesothelioma is rare. The cancer usually only has subtle symptoms at this stage, and these signs can be mistaken for other more common conditions like pneumonia or other respiratory infections.

Accurate and early detection is crucial for improving prognosis and treatment outcomes. Stage 1 mesothelioma is typically diagnosed through a combination of imaging tests and tissue biopsy procedures.

Diagnostic Imaging

Mesothelioma imaging tests are essential tools for visualizing the extent of the tumor and its location. Common imaging tests to diagnose stage 1 techniques used in diagnosing mesothelioma include:

X-rays

Chest X-rays are often the first imaging tool used to detect abnormalities, such as fluid buildup in the pleural space (pleural effusion), which may indicate mesothelioma.

CT scans

Computed Tomography (CT) scans provide more detailed images and can help identify the size, location, and extent of the tumor within the pleura or peritoneum. CT scans are instrumental in detecting early-stage tumors that might not be visible on routine X-rays.

MRI scans

Magnetic Resonance Imaging (MRI) scans may be employed for more detailed soft tissue evaluation, helping to assess the invasion of tumors.

These imaging studies often serve as initial diagnostic tools, but a biopsy is required to confirm the presence of mesothelioma and determine its staging.

Biopsy and Histological Analysis

A biopsy is the definitive method for diagnosing mesothelioma. A sample of the suspected tumor tissue is collected and examined under a microscope by a pathologist to identify the presence of cancerous cells. There are several types of mesothelioma biopsies:

Thoracoscopy – A minimally invasive procedure where a camera is inserted into the chest cavity to visually inspect the pleura and obtain tissue samples for biopsy
Laparoscopy – Similar to thoracoscopy but used to obtain samples from the peritoneal cavity in patients with peritoneal mesothelioma
Needle biopsy – A needle is used to obtain tissue from the tumor for examination. This method may be used when the tumor is accessible or when a thoracoscopy or laparoscopy is not feasible.

The tissue samples are examined for mesothelioma’s characteristic cell types, including epithelioid, sarcomatoid, and biphasic subtypes, which provide valuable information for treatment planning.

Challenges in Diagnosing Stage 1 Mesothelioma

Diagnosing stage 1 mesothelioma is rare due to its insidious onset and nonspecific symptoms.

According to a study published by Lung Cancer International, only 16% of pleural mesothelioma cases are diagnosed in stage 1, and just 5% of peritoneal mesothelioma cases are diagnosed in stage 1. Many people experience vague symptoms like chest pain, shortness of breath, or abdominal discomfort, which can be easily overlooked or attributed to more common conditions, delaying diagnosis.

The small size of the tumors in stage 1 mesothelioma can make them difficult to detect, and diagnosis is often not considered until symptoms are more pronounced.

Early detection is critical to improving survival outcomes for mesothelioma patients, particularly for those diagnosed at stage 1 when treatment options such as surgery, chemotherapy and radiation therapy are more effective.

What Signs and Symptoms to Expect With Stage 1 Mesothelioma

Stage 1 mesothelioma is often called the “silent” stage due to its subtle and sometimes minimal symptoms.

In many cases, people with stage 1 mesothelioma may not experience significant symptoms at all, which is one of the reasons why mesothelioma is often difficult to diagnose in this stage.

Visual representation of the human body and its organs, focusing on common symptoms of mesothelioma.

General Symptoms of Mesothelioma

Common Symptoms of Stage 1 Mesothelioma

Persistent cough – A dry or persistent cough is an early symptom of pleural mesothelioma, especially as the tumor begins to affect the pleura (the lining around the lungs). The cough may not resolve and may worsen over time.

Shortness of breath (Dyspnea) – As the tumor grows, it can cause a build-up of fluid in the pleural space (pleural effusion), which can compress the lungs and lead to difficulty breathing or shortness of breath. This may be mistaken for a mild respiratory condition in the early stages.

Chest or abdominal pain – Depending on the type of mesothelioma (pleural or peritoneal), people may experience localized pain in the chest or abdomen. In pleural mesothelioma, chest pain often results from the tumor invading the pleura or from fluid buildup. In peritoneal mesothelioma, abdominal discomfort or pain may be the primary symptom.

Loss of appetite and weight loss – Unexplained weight loss and a reduced appetite are common signs that may emerge as the body reacts to cancer growth.

Nausea – Particularly in cases of peritoneal mesothelioma, nausea can occur due to the presence of tumors in the abdominal cavity. This may also be related to digestive system disruption caused by the tumor’s growth.

Fatigue – While fatigue is a common symptom in many cancer types, it can be an early sign of mesothelioma as well. The body’s response to tumor growth, inflammation and the general toll of disease may lead to overall feelings of tiredness and lack of energy.

Understanding mesothelioma symptoms during stage 1 can help you identify a risk.

Stage 1 Mesothelioma Treatment Options

Due to the absence of metastasis, patients with stage 1 can achieve better long-term survival outcomes compared to those diagnosed at later stages.

The availability of various mesothelioma treatment options – including surgery, chemotherapy, immunotherapy and radiation therapy – further enhances the likelihood of disease control and symptom management, making early detection critical in mesothelioma care. Most mesothelioma clinical trials accept patients with stage 1 mesothelioma.

Surgery

Pleural Mesothelioma Surgery

Pleural mesothelioma surgery is often available to patients with stage 1 malignant pleural mesothelioma. The two surgeries for pleural mesothelioma are: pleurectomy with decortication (P/D) and extrapleural pneumonectomy (EPP).

P/D involves removing the lining of the lung, which is called the pleura. This surgery spares both lungs. It has an “extended” version, which removes part of the diaphragm and the lining around the heart (pericardium).

EPP is the complete removal of the affected lung, pleura and part of the diaphragm. It is the most aggressive surgery for pleural mesothelioma.

After EPP, the respiratory system can have limited working function and can put extra strain on the remaining lung. P/D is more common than EPP in stage 1 patients because the disease likely hasn’t spread to the lung yet.

Peritoneal Mesothelioma Surgery

Peritoneal mesothelioma surgery is often available to patients with stage 1 peritoneal mesothelioma. Patients usually undergo cytoreduction with heated intraperitoneal chemotherapy (HIPEC). Cytoreduction is the removal of all visible tumors and diseased tissue in the abdomen.

Heated intraperitoneal chemotherapy, or HIPEC, is an integral part of peritoneal mesothelioma surgery. This procedure uses a heated liquid chemotherapy solution placed directly into the abdominal cavity to attack cancer cells. Another common part of this surgery is a peritonectomy, which is the removal of the protective lining inside the abdomen (the peritoneum).

Pericardial Mesothelioma Surgery

Few cases of peritoneal mesothelioma are diagnosed in stage 1, which is why surgery is a rare treatment option for this type of mesothelioma.

Pericardial mesothelioma is a very rare cancer, and there are only a handful of cases diagnosed in the U.S. each year. It forms in the pericardium, which is a lining around the heart. The surgery for this type of mesothelioma is a pericardiectomy, which involves removing the pericardium.

Chemotherapy, Immunotherapy and Radiation

Chemotherapy, immunotherapy and radiation are mesothelioma treatment options for patients with stage 1 cancer. These therapies can be used on their own or in combination with other treatments, including surgery. They can reduce the size of tumors — making them easier to remove during surgery — or kill any remaining cancer cells left over from surgery.

Stage 1 mesothelioma patients may receive treatment aimed to relieve discomfort, including a thoracentesis (for pleural mesothelioma) and paracentesis (for peritoneal mesothelioma). These surgeries ease symptoms by reducing fluid buildup.

Prognosis and Survival Rate for Stage 1

The stage 1 mesothelioma prognosis is approximately 2 years with treatment. The earlier the disease is diagnosed, the more treatment options are available. The outlook for remission is also better than it is for the later stages.

According to a study with mesothelioma specialist Dr. David Sugarbaker, stage 1 pleural mesothelioma has an average prognosis of around 22 months. In a different study published on UpToDate, the stage 1 pleural mesothelioma life expectancy was 20 months.

The 1-year survival rate for stage 1 peritoneal mesothelioma is 71%. The 2-year survival rate for stage 1 peritoneal mesothelioma is 53%.

STUDYING SURVIVAL RATES BETWEEN EPP AND P/D

A study published in the Annals of Translational Medicine compared the survival rates for P/D and EPP:

Around 59% of P/D patients survived for two years.
Around 39% of EPP patients survived for two years.
The median survival time for P/D patients was 23.7 months, versus 18 months for EPP patients.

P/D also has less likelihood of postoperative complications. In one study, P/D patients had a lower 30-day mortality rate and fewer issues with irregular heart rhythms (arrhythmias).

Stage 1 by Mesothelioma Staging Systems

TNM System

The TNM (Tumor, Node, Metastasis) System is the standard method of staging pleural mesothelioma. It measures the collective size of the tumors, lymph node involvement and metastatic disease.

In stage 1 pleural mesothelioma, the TNM system shows the presence of cancer contained within the lining of the lungs, abdomen or heart. The cancer is localized to one side of the body (for pleural mesothelioma) and has not metastasized, or spread, to lymph nodes or other organs.

The TNM Staging System separates this stage 1 into sections: stage 1A and 1B. The difference between the two sub-stages is how much tumors have spread within the pleura, which is the small space between the pleura linings that surround the lungs.

Example of the TNM System

Illustrated depiction of a tumor, showing the TNM system used for cancer staging and assessment.

Diagram illustrating the TNM system for classifying cancer metastasis and the growth of cancer cells.

Butchart System

The Butchart System, developed in 1976, is the original staging method for pleural mesothelioma. This system divides mesothelioma into four stages (1-4), based on how far the cancer has spread within the pleura and to other organs. In this system, stage 1 pleural mesothelioma is characterized by localized tumors in one small area of the pleura.

Brigham System

The Brigham Staging System was developed at Brigham and Women’s Hospital in Boston, Massachusetts. It focuses on whether surgery is a treatment option for people with pleural mesothelioma. Doctors explicitly look for lymph node involvement. In stage 1, pleural mesothelioma has not spread to the lymph nodes, allowing tumors to be removed surgically.

Peritoneal Cancer Index

The Peritoneal Cancer Index (PCI) is the system used for staging peritoneal mesothelioma. The staging system divides the abdominal cavity into 13 sections, each with a score ranging from 0 to 3. The sections are then added together to get a total score between 0 and 39.

PCI scores from 0-10 for a peritoneal mesothelioma diagnosis are correlated to stage 1. If a patient has a PCI score no greater than 10, then their disease has not spread much. Surgery is often the first treatment option.

Example of the PCI System

Diagram illustrating the stages of the digestive system, highlighting the 13 abdominal regions and their Peritoneal Cancer Index scores.

PCI Score: 8 - Stage 1

Frequently Asked Questions About Stage 1 Mesothelioma

What is stage 1 mesothelioma?

Stage 1 of mesothelioma is the earliest stage of this cancer. The disease has not spread beyond the point of origin. For pleural mesothelioma, stage 1 means it was only found in the pleura. For peritoneal mesothelioma, it was only found in the peritoneum.

What are the symptoms of stage 1 mesothelioma?

The symptoms of stage 1 mesothelioma include coughing, shortness of breath, low-grade fever, fluid buildup in the chest or stomach, nausea, weight loss and decreased appetite. They are usually mild.

Is stage 1 mesothelioma curable?

There is no cure for mesothelioma, even in the earliest stage. However, stage 1 mesothelioma has the best overall prognosis and is the most treatable. The average prognosis for stage 1 mesothelioma is 2 years, although patients who receive successful surgery with other treatment options have improved survival of around 30 months.

How common is stage 1 mesothelioma?

A stage 1 mesothelioma diagnosis is rare, mostly due to the difficulty detecting the cancer at this stage. In one study, only 12% of mesothelioma cases were diagnosed in stage 1.

How can you treat stage 1 mesothelioma?

Treatment for stage 1 mesothelioma includes surgery, chemotherapy, immunotherapy and radiation therapy. Mesothelioma doctors may suggest surgery to remove the pleura or peritoneum, which is where mesothelioma originates. This treatment option often can eliminate most, if not all, of the tumors and diseased tissue.

Sources & Author

Life Expectancy in Pleural and Peritoneal Mesothelioma. Lung Cancer International. Retrieved from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5292397/. Accessed: 04/09/2020.
Presentation, initial evaluation, and prognosis of malignant pleural mesothelioma. UpToDate. Retrieved from: https://www.uptodate.com/contents/presentation-initial-evaluation-and-prognosis-of-malignant-pleural-mesothelioma?topicRef=4625&source=see_link. Accessed: 04/13/2020.
Extrapleural pneumonectomy (EPP) vs. pleurectomy decortication (P/D). Annals of Translational Medicine. Retrieved from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5497106/table/t5/. Accessed: 04/14/2020.
Short‐term outcomes of pleurectomy decortication and extrapleural pneumonectomy in mesothelioma. Journal of Surgical Oncology. Retrieved from: https://onlinelibrary.wiley.com/doi/abs/10.1002/jso.25260. Accessed: 04/14/2020.
Current Therapy for Mesothelioma. Brigham and Women’s Hospital. Retrieved from: https://journals.sagepub.com/doi/pdf/10.1177/107327489700400404. Accessed: 04/09/2020.
Cancer Staging. American Cancer Society. Retrieved from: https://www.cancer.org/treatment/understanding-your-diagnosis/staging.html. Accessed: 04/06/2020.
In Memoriam: David J. Sugarbaker, MD (1953–2018). Texas Heart Institute Journal. Retrieved from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6379011/. Accessed: 04/06/2020.
Peritoneal Cancer Index. ResearchGate. Retrieved from: https://www.researchgate.net/figure/Peritoneal-Cancer-Index-PCI-scoring-system-PCI-is-a-diagnostic-and-prognostic-tool_fig1_315691686. Accessed: 04/12/2020.
Malignant Mesothelioma Treatment (Adult). Vanderbilt-Ingram Cancer Center. Retrieved from: https://vicc.org/cancer-info/adult-malignant-mesothelioma. Accessed: 11/15/22.
Bonomi M, De Filippis C, Lopci E, et al. Clinical staging of malignant pleural mesothelioma: current perspectives. Lung Cancer (Auckl). 2017;8:127-139. Published 2017 Aug 18. doi:10.2147/LCTT.S102113
Martella S, Aiello MM, Bertaglia V, et al. Malignant Pleural Mesothelioma: Staging and Radiological Response Criteria in Patients Treated with Immune Checkpoint Inhibitors. Target Oncol. 2024;19(1):13-28. doi:10.1007/s11523-023-01017-w
Gill RR, Nowak AK, Giroux DJ, et al. The International Association for the Study of Lung Cancer Mesothelioma Staging Project: Proposals for Revisions of the “T” Descriptors in the Forthcoming Ninth Edition of the TNM Classification for Pleural Mesothelioma. J Thorac Oncol. 2024;19(9):1310-1325. doi:10.1016/j.jtho.2024.03.007

About the Writer, David Statman

David Statman is a Content Writer for Mesothelioma Guide. He received both his bachelor's and master's in journalism from West Virginia University, and has been in medical publishing since January 2022. He previously worked in sports journalism, primarily reporting on West Virginia sports for a number of publications.

He lives in Delaware with his wife, dog and two cats, and avidly competes as a professional wrestler in the Philadelphia area.