Biomarker Provides Potential New Way to Diagnose Sarcomatoid Mesothelioma

Sarcomatoid mesothelioma is the rarest of the three cell types of mesothelioma. Its uncommon nature is one reason why it’s challenging to identify and diagnose.

A new biomarker called GATA3 could help doctors and specialists recognize the cancer earlier, which should improve treatment possibilities for patients.

A study published in Human Pathology found that GATA3 was in a majority of sarcomatoid mesothelioma cases. It is especially reliable for detecting desmoplastic mesothelioma, which is a subset of the sarcomatoid cell type.

There are few reliable biomarkers for sarcomatoid mesothelioma, and finding additional ones can only help diagnose patients and select the appropriate therapeutic regimen. A lot of people ask, “How do you diagnose mesothelioma?” and the answer is tricky.

If you’d like to find a cancer center conducting similar research and advancing mesothelioma diagnostic and treatment practices, please contact our team. Karen Ritter, our registered nurse and patient advocate, can help you get in touch with one of many cancer centers dedicated to helping mesothelioma patients. Email her at karen@mesotheliomaguide.com.

 

GATA3 and Sarcomatoid Mesothelioma

GATA3 is a protein-coding gene in the body. It codes a protein with the same name, GATA3, which plays a role in regulating T-cell development. T-cells are the immune system’s primary defenders against viruses and cancers, including mesothelioma.

The study analyzed 149 cases and found GATA3 in approximately 50% (75) of them. The important news is which mesothelioma cell was most associated with this protein.

According to the report, GATA3 was in 73% of sarcomatoid mesothelioma cases. That high percentage hints that the biomarker is a positive indicator of this cancer.

The protein was in eight desmoplastic mesothelioma cases. This extremely rare type of the cancer involves an unstructured makeup of dense tissue fibers. The lack of a pattern to the tissue makes identifying desmoplastic mesothelioma incredibly difficult.

Another important element: GATA3 is far more common in sarcomatoid mesothelioma than the other two cell variations (epithelioid mesothelioma and biphasic mesothelioma).

There are two possible mesothelioma cells, epithelioid and sarcomatoid, but not all cases have just one or the other. Biphasic mesothelioma is a combination of both epithelioid cells and sarcomatoid cells. In contrast to the sarcomatoid mesothelioma percentage, GATA3 occurred in only:

• 50% of biphasic mesothelioma cases
• 40% of epithelioid mesothelioma cases

 

Why This Revelation Is Important

Distinguishing between the three cell variations is a major obstacle for doctors and even experienced pathologists. Using this new biomarker can help doctors differentiate between sarcomatoid and epithelioid — or a biphasic disease that includes more sarcomatoid cells than epithelioid cells.

Sarcomatoid cells and epithelioid cells spread and grow differently — at different speeds and in distinguishable ways. They often require a unique treatment approach, which is why distinguishing them is so important.

The life expectancy for sarcomatoid mesothelioma is the worst of the three cell types. The prognosis is usually less than a year for people with pleural mesothelioma and slightly more than one year for peritoneal mesothelioma.

Part of the reason this is the case is how rare the cell type is and the obstacles present in recognizing it. A delayed diagnosis means a more advanced disease, which limits treatment hopes for patients.

Sarcomatoid mesothelioma only occurs in 10-20% of cases. It’s less common than the biphasic mesothelioma and far less common than epithelioid mesothelioma. Due to so few cases, there aren’t many reliable biomarkers for sarcomatoid mesothelioma. There are even fewer biomarkers uniquely present in this cell type — meaning not also in epithelioid cells.

GATA3 seems to be an outlier and another advancement in the medical community learning about mesothelioma. With this discovery, doctors can diagnose this cancer earlier and help improve patients’ life expectancy.