Japanese researchers have introduced a new approach to mesothelioma staging. The new system may make it easier to plan treatment and predict mesothelioma prognosis.
Tumor staging is a system for measuring how far cancer has spread in the body. It is based on what doctors know about how cancer develops and grows. The more places mesothelioma cells are, the more difficult the case is to treat.
The TNM Staging System is the most widely used system for mesothelioma staging. The American Joint Committee on Cancer established the system.
In the TNM system, T stands for the size of the primary mesothelioma tumor. N stands for the spread of cancer to the lymph nodes. M is about cancer spread to other parts of the body.
A New Approach to Mesothelioma Staging
It is not easy to stage malignant pleural mesothelioma with accuracy. Pleural mesothelioma tumors grow on the lining around the lungs. Their irregular shape can make it hard to decide how big they are. (The “T” part of the TNM Staging System.)
Now, researchers at the Hyogo College of Medicine say they have found a way to make mesothelioma staging simpler.
The researchers analyzed the cases of 104 pleural mesothelioma patients between 2007 and 2016. These patients all had chemotherapy first, followed by mesothelioma surgery.
The research team used patients’ CT scans to measure the thickness of the pleural lining in three places: the upper chest, the mid-chest, and the lower chest. Researchers took measurements before and after chemotherapy.
Pleural Thickness Impacts Mesothelioma Prognosis
Mesothelioma staging is not just for interest. Doctors use the numbers of the TNM Staging System to choose which mesothelioma treatments to try. Cancer stage also helps patients and doctors predict treatment response.
In an article in the Journal of Thoracic and Cardiovascular Surgery, the Japanese researchers explained how they came up with two sets of numbers based on pleural thickness measurements.
They labeled the highest of the three measurements “max”. Then they totalled up the three pleural thickness measurements and called it “sum”.
The post-chemotherapy “max” and “sum” numbers were associated with overall mesothelioma survival and recurrence-free survival.
As the authors of a separate article in the same issue observe, lower numbers mean surgeons have “a thinner peel to peel” when they go in to remove the mesothelioma tumor.
The team concluded that the sum of pleural thickness in 3 areas of the chest is a new way to stage mesothelioma and predict mesothelioma prognosis.
“Our measurement procedure is quite simple, and could be used throughout the world,” writes lead researcher Masaki Hashimoto, MD, PhD. “Because this procedure does not require any specific device or software, it has potential as a new T-component.”
Hashimoto, M, et al, “Pleural thickness after neoadjuvant chemotherapy is a prognostic factor in malignant pleural mesothelioma”, January 2019, Journal of Thoracic and Cardiovascular Surgery, pp. 404-413, https://www.jtcvs.org/article/S0022-5223(18)32615-1/fulltext