For the first time since 2018, the American Society of Clinical Oncology (ASCO) has released new guidelines for treating mesothelioma, an aggressive cancer caused by asbestos exposure.
The 2025 update is specific to pleural mesothelioma, which forms in the lining of the lung, and reflects data from 110 peer-reviewed studies. The ASCO guidelines help doctors determine the best practices for diagnosing and treating this rare cancer.
The updated guidelines focus on four key areas:
- The Role of Surgery
- New Systemic Treatments
- Pathologic Insights
- Genetic Testing
Learn more about the new guidelines for mesothelioma treatment and what they mean for patients.
1. The Role of Surgery
Surgery is a treatment option for pleural mesothelioma, but results from the MARS 2 trial show that it may not be as effective as doctors once thought. In the new guidelines, surgery is only recommended in specific circumstances.
Here are some key surgery-related takeaways:
- Surgery isn’t the right choice for all cases, even if the tumors can be removed. The best candidates for surgery are patients with early-stage epithelioid mesothelioma.
- For patients who qualify, post-surgery immunotherapy should no longer be offered as a treatment option since there’s limited evidence of its effectiveness. However, these patients can still get immunotherapy before surgery.
- The timing of systemic therapy isn’t a major factor, so it can continue to be offered before or after mesothelioma surgery.
These latest recommendations will help mesothelioma specialists better determine the role of surgery in each patient’s treatment plan.
Get our Free Mesothelioma Guide to learn more about surgery and other treatments that can help you or a loved one.
2. New Systemic Treatments
Systemic treatments are designed to treat the entire body. They are commonly used in mesothelioma treatment since cancer cells can spread to different areas. A systemic treatment can circulate anywhere the cancer cells might be.
Chemotherapy is one of the most common systemic treatments used to fight mesothelioma and other cancers. Chemo medication flows through the bloodstream to kill cancer cells throughout the body.
The ASCO guidelines highlight these recent advancements in systemic treatment:
- The U.S. Food and Drug Administration (FDA) approved the immunotherapy drugs Opdivo® and Yervoy® for pleural mesothelioma in October 2020.
- Keytruda®, an immunotherapy already used to treat other types of cancers, was approved for mesothelioma in September 2024 in combination with chemotherapy.
- Pemetrexed is still the gold-standard chemotherapy drug for mesothelioma, but it’s no longer recommended for maintenance after treatment.
As research continues, new and improved systemic treatments will help doctors learn more effective ways of targeting mesothelioma cells.

“For a disease in which for 16 years there was only one FDA-approved regimen, the pace of recent changes in systemic therapy has been a welcome change.”
3. Pathologic Insights
Pathologic insights help doctors understand what causes an illness, how it spreads, and how to diagnose and treat it effectively.
This information is especially important because of how challenging it is to diagnose mesothelioma. Not only are symptoms similar to other illnesses, but mesothelioma cells can be hard to distinguish from other types of cancers.
Here are the main updates regarding mesothelioma pathology:
- The medical term “malignant mesothelioma” has been simplified to just “mesothelioma” since the disease is already understood to be cancerous.
- Mesothelioma must now be reported as one of three subtypes: epithelioid, sarcomatoid, or biphasic. The mesothelioma cell type helps determine whether chemotherapy or immunotherapy is the best treatment.
- Thoracoscopy is now the preferred way to diagnose mesothelioma because it gives a clearer picture of how far the disease has spread and helps doctors plan the best treatment.
4. Genetic Testing
Genetic testing, also called germline testing, is a critical part of discovering how patients develop mesothelioma. Some people get mesothelioma without being exposed to asbestos, and mutations in the BAP1 gene may be a reason why.
Medical experts can use the DNA obtained from genetic testing to make critical decisions about a patient’s prognosis and the best approach to treatment.
Here are some of the ASCO updates related to genetic testing:
- Genetic testing is now recommended for all pleural mesothelioma patients upon diagnosis.
- Gene variants have been found that increase the risk of passing down a higher likelihood of developing mesothelioma from a parent to their children.
- Inherited BAP1 mutations have been associated with long-term survival in patients with mesothelioma. That means it’s possible to inherit genes from your parents that influence your mesothelioma prognosis.
As testing advances, understanding each patient’s genetics will become a greater aspect of mesothelioma diagnosis and treatment.
The Impact of the Updated ASCO Treatment Guidelines
The revised ASCO guidelines are important for helping doctors, surgeons, and researchers better understand pleural mesothelioma.
This can lead to earlier diagnosis, improved treatment options, and higher survival rates. By following these new guidelines, medical professionals worldwide can work together to improve care for those with mesothelioma.
Patients are the ones who will ultimately benefit from these updates. With every improvement, the best practices used to treat mesothelioma will evolve, becoming more comprehensive and effective.



“Even as we were researching and writing this update, new data kept emerging which we needed to include. So it’s clearly a time of great progress in the management of this disease.”
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Whether it’s updated treatment guidelines or groundbreaking research on new ways to combat this disease, Mesothelioma Hope is dedicated to providing the latest news for patients and their loved ones.
If you’ve been diagnosed with mesothelioma, we can help. Our team can connect you with specialists who have experience with the latest treatments.
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