Certain factors determine the prognosis of mesothelioma, including the cancer stage at diagnosis, the cell type, treatment options, and the patient’s age and overall health. While treatment can extend the average life expectancy of mesothelioma, there is still no confirmed cure, and it is considered a terminal cancer.
Medically Reviewed By:
Patricia Shelton, M.D.
Medically Reviewed By:Patricia Shelton, M.D.
Malignant mesothelioma is a rare type of cancer that forms in certain types of membranes in the body, most commonly the pleura (the lining around the lung) or the peritoneum (around the digestive tract). In general, this is an aggressive cancer, and life expectancy without treatment may only be a few months. Treatment can extend life for many patients, but mesothelioma is generally considered a terminal disease. Long-term remission is very rare, although it has occurred in some cases. Clinical trials are ongoing, and new treatments may help to improve the prognosis for mesothelioma patients.
How do we measure
The prognosis of a disease is what doctors predict will be the likely outcome of the disease. It’s very important to understand that the prognosis is only an estimate. It’s not possible to accurately predict the exact outcome for any particular patient. The question at the forefront of every cancer patient’s mind is, “How much time do I have left?” The answer to that question may be difficult for doctors to predict with a high degree of certainty.
However, doctors can use survival statistics to predict the most likely outcome. There are a few different ways to look at the prognosis of a particular type of cancer.
The life expectancy and survival rates vary for patients depending on the type of mesothelioma and a variety of other factors. Some of the important prognostic factors include:
While it’s important to be realistic about the likely outcomes, it may be helpful to know that there have been reported cases of mesothelioma patients living significantly longer than was predicted.
Each patient must decide whether he or she wants to receive potentially life-extending treatments for mesothelioma. Some patients are willing to endure the side effects of these treatments in order to have more time with their loved ones. Others would rather focus on quality of life rather than length of life and opt to receive palliative care only.
Pleural Mesothelioma Prognosis
Malignant pleural mesothelioma is found in the pleura, which is the lining of the lungs. This is the most common form of mesothelioma diagnoses, accounting for about 80 percent of the total cases. Pleural mesothelioma tends to have a poor prognosis overall, with the American Cancer Society reporting a five-year relative survival rate of only 12 percent.
Patients whose disease is more advanced at the time of diagnosis generally have a shorter life expectancy than those who are in an early stage when mesothelioma is found. Mesothelioma stages may be determined in a few different ways. American Cancer Society data indicates that five-year survival rates are:
Pleural mesothelioma stages are commonly described according to the TNM staging system, which uses three main characteristics of the cancer to determine the stage. Using this system, a study in the Journal of Thoracic Oncology found that the life expectancy by stage was:
This study included patients with varied mesothelioma treatment plans. A 2019 study found that overall survival in pleural mesothelioma patients who didn’t receive any treatment was about 10 months.
Unfortunately, due to factors like the long latency period between asbestos exposure and mesothelioma diagnosis, many patients are diagnosed in later stages. Early detection gives patients more treatment options and is associated with longer survival.
Treatment for malignant pleural mesothelioma can make a difference in the prognosis. Treatment options may include surgery, chemotherapy, radiation therapy, and/or immunotherapy. Many patients receive multimodal therapy, in which multiple types of treatments are used.
For patients who are eligible for tumor-removing surgery, extrapleural pneumonectomy (EPP) or pleurectomy/decortication (P/D) are the two main surgical options. EPP is a significantly more invasive procedure with more side effects, and research currently indicates that with modern surgical techniques, survival rates after P/D are equivalent to or even better than survival rates after EPP. Because of this, some surgeons believe that EPP should no longer be performed, although there are also surgeons who believe that it has a role in particular patients.
Some patients have tumors that cannot be removed surgically, either because the cancer has invaded local structures (such as the chest wall) or has spread to lymph nodes or other organs. For these patients, chemotherapy is generally the recommended form of treatment. An analysis of data from a large group of mesothelioma patients treated at Memorial Sloan Kettering Cancer Center showed that chemotherapy improved survival by a modest amount, with patients who received multiple chemotherapy agents (such as pemetrexed plus cisplatin) showing better results than those who received just one chemotherapy medication.
In the same study, patients who received definitive radiotherapy (radiation therapy intended to eliminate the tumor) along with chemotherapy also had improved results, with median survival of nearly 15 months (compared with about 10 months for those receiving no treatment). While some studies have not shown a benefit for patients receiving radiation therapy after surgery and chemotherapy, the overall consensus of experts in the field is that radiotherapy does offer a survival benefit in carefully selected patients.
Immunotherapy is the newest treatment option for malignant pleural mesothelioma patients. A 2021 clinical trial showed overall survival of about 18 months in patients treated with a combination of immunotherapy drugs (Opdivo and Yervoy), compared with about 14 months in those who received standard chemotherapy.
It’s very important to note that the treatment plan must be individualized for each patient. The appropriate treatment options for a given patient will differ based on various factors. For example, only patients with early-stage mesothelioma who are in good overall health are eligible for tumor-removing surgery. Your cancer care team will discuss with you what treatment options you may consider. It’s then up to you to decide which ones you want to receive based on your goals for your cancer treatment.
Peritoneal Mesothelioma Prognosis
Malignant peritoneal mesothelioma is found in the peritoneum, which is the lining around the digestive system. This is a less common type of mesothelioma, accounting for fewer than 20 percent of cases. Life expectancy is about five months in patients whose cancers don’t respond to treatment. However, treatment can make a significant difference for some patients.
As with most other types of cancer, prognosis for patients with malignant peritoneal mesothelioma is impacted by stage. One study found that patients whose cancer had already spread to lymph nodes at diagnosis had a five-year survival rate of 18 percent, compared to 82.5 percent in those who did not have spread to lymph nodes.
Patients whose disease has not yet spread to the lymph nodes or to distant organs are candidates for the most effective treatment for peritoneal mesothelioma. This is a combination of surgery and chemotherapy known as CRS-HIPEC (cytoreductive surgery with hyperthermic intraperitoneal chemotherapy).
For peritoneal mesothelioma patients who receive CRS-HIPEC, the prognosis is significantly improved. Over various studies at different institutions, average life expectancy after this procedure has been found to be 34 to 92 months, and five-year survival rates are 29 to 59 percent. The variations between the numbers found in different studies are believed to be related to the amount of experience that a cancer center has with performing CRS-HIPEC, since the details of the surgical technique may influence the outcome. Choosing an expert who has performed this procedure regularly may increase the chances of a good outcome from the procedure.
For patients who are not candidates for CRS-HIPEC, systemic chemotherapy is the most commonly used treatment. There is actually not much research on this treatment for peritoneal mesothelioma specifically; oncologists generally assume that since it’s effective for pleural mesothelioma, it will also help patients with peritoneal mesothelioma, but the rarity of this disease makes it difficult to study. Two studies have shown that using pemetrexed plus cisplatin leads to overall survival of 13.1 months, compared with 8.7 months when only pemetrexed is used.
Prognosis for Rare Types of Mesothelioma
There are two types of mesothelioma that are far more rare than pleural or peritoneal mesothelioma.
Cancer research is ongoing, and scientists are studying new types of treatment as well as new combinations of existing treatments in hopes of improving the prognosis for mesothelioma patients.
Some patients choose to enroll in clinical trials, which are research studies of medical treatments. The National Cancer Institute maintains a database of clinical trials that are currently enrolling patients; you can search for your type of mesothelioma to find the trials that would be relevant for you. A trial may have specific requirements, such as being in a certain stage, so you’ll need to check the details to determine eligibility.
Many patients are excited about the idea of clinical trials because they offer the possibility of getting early access to a potentially life-extending new treatment modality. However, there are tradeoffs to participating in a trial. Although many new cancer treatments show promise, there’s no guarantee that the new treatments will work better than the existing ones. Additionally, clinical trials are often designed with a control group, which means that not everyone who participates in the study will actually receive the experimental treatment.
If you’re considering being part of a clinical trial, you should discuss this idea with your cancer care team. An expert in oncology can help you learn more about the risks, benefits and eligibility requirements associated with participating.