What the Newly Published 2026 NCCN Guidelines Mean for Mesothelioma Patients

For someone diagnosed with pleural mesothelioma, treatment decisions can feel overwhelming. Surgery, chemotherapy, immunotherapy, radiation and clinical trials may all be discussed, and the best approach can vary considerably from one person to another.

A major new update from the National Comprehensive Cancer Network (NCCN) provides an important picture of where mesothelioma treatment stands in 2026. The guideline, “Mesothelioma: Pleural, Version 3.2026,” emphasizes a significant change from some earlier approaches: systemic treatment, particularly immunotherapy and/or chemotherapy, is now the main treatment for most people with pleural mesothelioma, while surgery is reserved for a much smaller group of carefully selected patients.

The paper was authored by James Stevenson, MD; Gregory J. Riely, MD, PhD; Douglas E. Wood, MD; Dara L. Aisner, MD, PhD; Andrea L. Axtell, MD, MPH; Jessica R. Bauman, MD; Ankit Bharat, MD; Joe Y. Chang, MD, PhD; Aakash Desai, MD, MPH; Thomas J. Dilling, MD, MS; Jonathan Dowell, MD; Gregory A. Durm, MD, MS; Scott Gettinger, MD; Travis E. Grotz, MD; Matthew A. Gubens, MD, MS; Aditya Juloori, MD; Rudy P. Lackner, MD; Michael Lanuti, MD; Benjamin Levy, MD; Jules Lin, MD; Billy W. Loo Jr, MD, PhD; Christine M. Lovly, MD, PhD; Fabien Maldonado, MD; Daniel Morgensztern, MD; Trey C. Mullikin, MD; Thomas Ng, MD; Dawn Owen, MD, PhD; Dwight H. Owen, MD, MSc; Tejas Patil, MD; Patricio M. Polanco, MD; Jonathan Riess, MD, MS; Ana Lucia Ruano Mendez, MD; Theresa A. Shapiro, MD, PhD; Aditi P. Singh, MD; Alda Tam, MD; Tawee Tanvetyanon, MD, MPH; Jane Yanagawa, MD; Edwin Yau, MD, PhD; Karen Yun, MD; Kristina Gregory, RN, MSN; and Lisa Hang, PhD.

The Importance of an Accurate Diagnosis and Tumor Type Identification

Pleural mesothelioma develops in the lining around the lungs and accounts for about 85% of all mesotheliomas. The NCCN paper notes that approximately 3,000 people are diagnosed in the United States each year. Unfortunately, many people are diagnosed when the disease is already advanced.

The first step is making sure the diagnosis is accurate. When doctors suspect mesothelioma, the recommended evaluation includes a chest CT with contrast, testing of fluid around the lung and, importantly, a biopsy of the pleura. A thoracoscopic biopsy is the preferred biopsy approach when appropriate. Fluid testing alone can miss mesothelioma, so a negative fluid sample does not necessarily rule it out.

After biopsy, the pathology report is crucial because mesothelioma comes in three main forms or subtypes: epithelioid, sarcomatoid or biphasic. Epithelioid is the most common subtype and generally has a more favorable outlook. Sarcomatoid and biphasic disease tend to behave more aggressively. Knowing the subtype helps doctors determine which treatments are most appropriate.

A Multidisciplinary Treatment Approach

The guidelines strongly recommend that people with pleural mesothelioma be evaluated by a multidisciplinary team with experience treating the disease. Such a team can include radiologists, pulmonologists, surgeons, medical oncologists and radiation oncologists. CT scans of the chest and abdomen are recommended for staging and treatment planning.

This is particularly important because mesothelioma is uncommon and treatment decisions can be complicated. The guidelines make clear that factors such as cancer stage, tumor type, overall health and ability to tolerate treatment all influence the recommendation.

Immunotherapy as the Go-To First-Line Therapy

One of the biggest developments reflected in the 2026 guidelines is the growing role of immunotherapy.

For people with unresectable pleural mesothelioma, two immunotherapy-containing approaches are listed as preferred, category 1 first-line treatments:

1. nivolumab plus ipilimumab, or pembrolizumab combined with platinum chemotherapy and pemetrexed. The guidelines state that PD-L1 testing is not required before prescribing one of these immunotherapy regimens. The evidence is encouraging. In the CheckMate 743 trial, patients receiving nivolumab plus ipilimumab had a median overall survival of 18.1 months, compared with 14.1 months for patients receiving chemotherapy alone. The benefit was particularly noticeable among people whose tumors were sarcomatoid or biphasic rather than epithelioid.
2. Another large trial found that adding pembrolizumab to platinum chemotherapy and pemetrexed produced a median overall survival of 17.3 months, compared with 16.1 months with chemotherapy alone.

These numbers are population averages, not predictions for an individual patient. Still, they demonstrate how substantially the treatment landscape has changed.

Surgery is More Selective Since MARS2 Clinical Trial

Perhaps the most important message for patients is the guideline’s position on surgery.

For years, aggressive surgery was often incorporated into treatment plans for patients whose mesothelioma appeared removable. The two major operations are pleurectomy/decortication, which attempts to remove the tumor while preserving the lung, and extrapleural pneumonectomy, which removes the affected lung along with surrounding tissue.

But recent randomized clinical trials have changed the thinking.

The MARS trial found that patients undergoing extrapleural pneumonectomy had worse survival and quality-of-life results than those who did not have the operation. Median survival was 14.4 months with surgery versus 19.5 months without it.

The larger MARS2 trial subsequently compared chemotherapy alone with chemotherapy plus lung-sparing surgery. Median overall survival was 24.8 months with chemotherapy alone versus 19.3 months with chemotherapy plus surgery. Surgery was also associated with more serious side effects, worse quality of life and substantially higher healthcare costs.

As a result, the NCCN panel now recommends systemic therapy rather than routine surgery for most patients.

That does not mean surgery has disappeared. The guidelines say it can still be considered for carefully selected patients with stage I epithelioid mesothelioma, good overall physical condition and enough lung and heart function to tolerate an operation. When surgery is chosen, pleurectomy/decortication is preferred over extrapleural pneumonectomy.

For stage II through IV disease, surgery is no longer recommended as a primary treatment. Surgery is also not recommended for sarcomatoid or biphasic mesothelioma.

Radiation Continues to Have a Role

Radiation therapy has not disappeared from the treatment picture. Specialized pleural radiation, known as intensity-modulated radiation therapy or IMRT, may be considered for selected patients, particularly those with earlier-stage epithelioid disease who have received systemic treatment and possibly surgery. Because treating the pleura while protecting the lung and heart is technically difficult, the guidelines recommend that this treatment be performed at experienced centers.

Radiation can also be used to relieve symptoms, including pain or problems caused by tumors pushing or interfering with particular areas of the body.

Controlling Symptoms

Treatment is not only about trying to slow the cancer. The guidelines also emphasize managing symptoms and maintaining quality of life.

Fluid buildup around the lung, called a pleural effusion, can cause significant shortness of breath. Doctors may drain the fluid, perform a procedure called pleurodesis to reduce recurrent fluid buildup, or place a catheter that allows fluid to be drained as needed.

For people who are too ill to tolerate aggressive cancer treatment, the guidelines recommend supportive care focused on comfort. Radiation and other procedures can sometimes be used to relieve specific symptoms.

What Should Patients Take Away from These Guidelines?

The biggest takeaway is that mesothelioma treatment in 2026 should be tailored to the patient and their individual circumstances and needs.

The NCCN guidelines no longer view major surgery as the default approach even when mesothelioma appears technically removable. Instead, systemic therapy is the foundation of treatment for most patients. Immunotherapy has become an important option, while surgery is reserved for a small, carefully selected group.

For someone newly diagnosed, the most important questions may therefore be:

1. What stage is my disease?
2. What is my histologic subtype?
3. Am I medically fit enough for aggressive treatment?
4. What systemic therapy is appropriate?
5. Has my case been reviewed by a specialized multidisciplinary team experienced in treating mesothelioma?

The authors conclude that treatment decisions should take into account stage, tumor subtype, medical fitness and performance status, with specialized multidisciplinary care playing a central role. Carefully selected patients with stage I epithelioid disease may still be candidates for treatment involving surgery, but for most patients, systemic therapy is now the preferred starting point.

 

Reference: Stevenson J, Riely GJ, Wood DE, et al. Mesothelioma: Pleural, Version 3.2026. Journal of the National Comprehensive Cancer Network. 2026;24(8):e260038. doi:10.6004/jnccn.2026.0038.