What Is Stage 4 Mesothelioma?
Stage 4 mesothelioma generally refers to malignant (cancerous) mesothelioma that has spread from the location where it first appeared to distant parts of the body.
Depending on the type, mesothelioma may first appear in the:
- Pleura: The lining of the lungs and chest wall
- Peritoneum: The lining of the abdominal cavity
- Pericardium: The lining of the heart
- Tunica vaginalis: The membrane lining the testes
Stage 4 mesothelioma is the final stage of mesothelioma under the tumor-node-metastasis (TNM) staging system. In the United States and many other countries, the TNM system is the most widely used system for measuring how far most cancers have progressed.
Doctors use the TNM system to help malignant pleural mesothelioma patients understand the extent of their cancer, how long they can expect to live, and what treatment options may help.
Stage 4 Pleural Mesothelioma
The only officially staged type of mesothelioma is pleural mesothelioma. Stage 4 pleural mesothelioma is described as cancer that has used lymph nodes or blood vessels to travel to distant parts of the body, forming new tumors.
At this advanced stage, life-extending treatments may be extremely limited or unavailable.
Stage 4 Peritoneal Mesothelioma
Peritoneal mesothelioma has no official staging system. However, some oncologists (cancer doctors) have proposed a staging system for peritoneal mesothelioma that has yet to be approved by the TNM staging system’s creators, the American Joint Committee on Cancer (AJCC) and the International Union Against Cancer (UICC).
Under this unofficial staging system, stage 4 peritoneal mesothelioma involves extensive tumor spreading.
- According to the American Cancer Society (ACS), only 8% of mesothelioma patients with distant or stage 4 mesothelioma survive 5 years after diagnosis.
- Unlike many other forms of cancer, stage 4 mesothelioma tends to remain in the body cavity it originated in. For example, pleural mesothelioma often remains in the chest.
- During stage 4, mesothelioma has usually spread too far for patients to undergo life-extending surgery. However, chemotherapy and treatment through clinical trials may help.
How Late-Stage Mesothelioma Develops
According to the Centers for Disease Control and Prevention (CDC), mesothelioma may take around 20-50 years to develop after a patient has been exposed to asbestos — the only known cause of the cancer. However, once symptoms appear, the disease progresses rapidly.
As mesothelioma cancer cells multiply, they cause tumors to grow and spread. Eventually, these cancer cells may travel through the lymph nodes or blood vessels, forming new tumors far from where they originated — a process called metastasis.
Stage 4 mesothelioma marks the point when the cancer has metastasized (spread to distant parts of the body).
The TNM system describes stage 4 mesothelioma in the following manner:
- Tumor: Cancer may or may not have grown into nearby tissues and other body parts.
- Node: The cancer may or may not have spread to lymph nodes — either nearby or on the other side of the body.
- Metastasis: Cancer has spread to distant organs, such as the bones, the liver, lungs, etc.
As mesothelioma progresses from stage 3 to stage 4, large and spreading tumors cause patients to experience the most severe mesothelioma symptoms.
Stage 4 Mesothelioma Symptoms
During stage 4, the symptoms commonly experienced by mesothelioma patients worsen. As the cancer spreads to other parts of the body, new symptoms may arise or extend to other areas.
Common symptoms of stage 4 mesothelioma include:
- Abdominal pain
- Chest pain
- Chronic fatigue
- Coughing up blood
- Difficulty swallowing
- Extreme weight loss
- Muscle atrophy
- Night sweats
- Shortness of breath
Even at this late stage, the symptoms of mesothelioma are not unique to the disease, but symptoms are more than noticeable enough for patients to bring to their doctors who can run tests in an attempt to identify the problem.
Stage 4 Mesothelioma Diagnosis
Sadly, many mesothelioma patients are diagnosed during stage 4 because this is when symptoms are most prominent. Since mesothelioma is so rare, many doctors may not immediately consider the possibility that a patient has it unless they are aware of the patient’s exposure to asbestos. Misdiagnosis may also contribute to an advanced-stage mesothelioma diagnosis.
Doctors may use the following to help diagnose stage 4 mesothelioma:
- Knowledge of a patient’s asbestos exposure history
- Patient’s description of symptoms
- Physical exam
- X-rays and other imaging tests
- Blood tests
A biopsy involves the removal of a tissue sample from a patient’s tumor, thickened organ lining, or fluid around the cancer site. By examining this tissue under a microscope, a doctor can determine if any of its cells are cancerous.
Ultimately, a mesothelioma diagnosis can only be confirmed by performing a biopsy.
Stage 4 Diagnosis and Mesothelioma Staging Systems
Once mesothelioma has been diagnosed, doctors use a staging system to find out how far the patient’s cancer has advanced and how they can expect it to progress.
While other systems exist (for pleural mesothelioma only), the TNM staging system is the most widely accepted. Each system focuses on different aspects of mesothelioma, describing stage 4 in its own way.
Stage 4 Pleural Mesothelioma By Staging System
- Butchart System: The cancer has metastasized, spreading to distant parts of the body.
- Brigham System: There are distant metastases. Tumors are not surgically removable.
- TNM System: Mesothelioma may or may not have grown into nearby tissues and may or may not have spread to nearby lymph nodes. However, it has spread to distant organs.
Around the world, many medical communities use the TNM staging system for its simplicity and practicality in terms of understanding a patient’s prognosis.
Stage 4 Mesothelioma Prognosis
A prognosis describes how a disease is expected to progress. The stage of a patient’s mesothelioma at diagnosis is a major factor in determining their mesothelioma prognosis.
Mesothelioma has a poor prognosis in general, and patients diagnosed at stage 4 have the poorest outlook. However, some stage 4 patients may extend their lives with chemotherapy and other treatments.
Palliative treatment may also relieve symptoms, making life with mesothelioma easier.
Stage 4 Mesothelioma Life Expectancy
The average amount of time doctors expect a mesothelioma patient to live after diagnosis is known as mesothelioma life expectancy. For this aggressive cancer, life expectancy is often measured in months.
According to a mesothelioma review published in the West Virginia Medical Journal, the median survival time for malignant mesothelioma of all types is 6-13 months overall and 6-18 months with treatment.
Stage 4 patients, who are often not able to undergo the most effective life-extending treatments, can generally expect to live at the shorter end of this range. However, chemotherapy may increase life expectancy.
Stage 4 Mesothelioma Treatment
Stage 4 malignant mesothelioma treatment may involve surgery, chemotherapy, radiation, and/or new treatments through clinical trials.
However, chemotherapy alone is the standard recommended treatment for patients with stage 4 mesothelioma.
Stage 4 Mesothelioma Surgery
Stage 4 mesothelioma is usually not able to be operated on because cancer cells have spread to distant parts of the body, growing new tumors. At this stage, the cancer is too widespread for surgeons to effectively remove enough of it, and patients may be too sick to undergo invasive surgeries such as an extrapleural pneumonectomy (EPP) or pleurectomy with decortication (P/D).
However, surgery may still help relieve symptoms and treat complications caused by tumor growth through partial tumor removal.
Stage 4 Mesothelioma Chemotherapy
Chemotherapy, cancer-destroying medicine administered intravenously, is the standard treatment option for stage 4 mesothelioma patients.
While some individuals respond well to mesothelioma chemotherapy, a mesothelioma literature review published in the Ochsner Journal found that nearly two-thirds of mesothelioma chemotherapy patients do not respond to the preferred cisplatin and pemetrexed chemotherapy drug combination.
However, a new type of chemotherapy known as targeted therapy shows some promise as a more effective mesothelioma treatment option. Several targeted therapies are currently being studied in clinical trials.
Stage 4 Mesothelioma Radiation Therapy
During mesothelioma radiation therapy, doctors use high-energy rays to destroy the DNA of mesothelioma cancer cells.
For stage 4 mesothelioma patients, radiation therapy is most commonly used to help shrink tumors that can be directly targeted, relieving pain.
Many advanced-stage mesothelioma patients do not respond effectively to typical cancer treatments like surgery, chemotherapy, and radiation. However, other options are available.
Other Treatment Options
Stage 4 mesothelioma patients are often not ideal candidates for the most commonly applied treatments. However, some late-stage patients may find better results by participating in a clinical trial.
Mesothelioma clinical trials test emerging treatments for the disease to improve the treatment options that are currently available.
Emerging mesothelioma treatments include:
- Gene therapy
- Photodynamic therapy
Patients should keep the stage of their mesothelioma in mind when searching for clinical trials. Many trials restrict patients by cancer stage.
Stage 4 Mesothelioma Palliative Care
Palliative care describes treatment aimed not at extending life but at decreasing pain and increasing comfort and wellbeing. Many stage 4 mesothelioma patients do not receive much benefit from chemotherapy and cannot undergo surgery to extend their lives.
Therefore, doctors focus on reducing their symptoms and giving them the best quality of life possible during the final stage of their cancer.
Palliative care options for stage 4 mesothelioma include:
- Chemotherapy: Chemotherapy helps reduce the size of tumors, easing symptoms.
- Medication: Doctors may prescribe medication such as morphine to help patients manage their pain.
- Radiation: Like chemotherapy, radiation may shrink cancerous tumors and ease symptoms.
- Low-risk surgeries: Palliative surgery for mesothelioma may reduce fluid buildup or partially remove tumors.
For those who have reached the final stage of their mesothelioma, palliative care is central to optimal treatment.
End-of-Life Planning and Living With Stage 4 Mesothelioma
Stage 4 mesothelioma is the final stage of this aggressive cancer, and many patients live fewer than 6 months after diagnosis.
While such a diagnosis can be devastating, patients may ease anxiety and improve their general wellbeing by managing their treatment and making an end-of-life plan. Below, learn more about what this plan may include.
Patients should speak with their loved ones about where they wish to receive end-of-life care (hospital, hospice, at home, etc.) and whether they would like to designate someone as their caregiver.
Care of Dependents
Patients with dependent children or grandchildren, pets, or anyone else reliant on their care should make arrangements to make sure those who survive them are taken care of.
Patients should let loved ones know how they want their body to be handled (cremation, burial, etc.), details about the funeral service, and any special religious requests.
A trusted loved one should have access to any important information they may need to know, such as the patient’s social security number and passwords.
A patient’s treatment team should know their priorities when it comes to treatment. Do they want to focus on extending survival time or easing symptoms? At some point, patients may wish to end all standard cancer treatments like chemotherapy and surgery.
Will and Other Finances
Patients should review or draft a will and make sure to account for all income and assets, such as investments, personal possessions, and other forms of compensation.
An advance directive also gives you the opportunity to spell out your decisions regarding end-of-life care in advance. This includes whether or not you wish to receive life-sustaining therapies such as CPR, being on a breathing machine (ventilator), artificial nutrition, or hydration.
While these decisions may be difficult to discuss with your doctor or family, doing so ahead of time ensures that your wishes are followed, minimizing any unwanted procedures or unnecessary suffering.
Patients can ask their medical team for recommended end-of-life care documents and where they may receive further end-of-life planning assistance.
By working with their care team and planning ahead, stage 4 mesothelioma patients may experience a greater sense of peace and satisfaction at the end of their lives.