A new study explains how the staging system for malignant pleural mesothelioma could be improved.
By taking tumor volume and weight into consideration, doctors may be able to diagnose their mesothelioma patients more accurately. More accurate scoring would help doctors create more accurate treatment plans for patients.
Using Tumor Volume to Stage Mesothelioma
The most commonly used scoring system takes into account if the tumor has spread to other parts of the body and the size of the tumor. This new study, written by Dr. Wickii Vigneswaran, argues that the weight and volume of tumors may be important factors to consider in staging mesothelioma.
Dr. Wickii Vigneswaran is the division director of Thoracic Surgery at Loyola University Medical Center and a professor at Loyola University Chicago Stritch School of Medicine. He is highly experienced in treating mesothelioma patients and has performed nearly 200 mesothelioma surgeries.
The title of the study is, “Specimen weight and volume: important predictors of survival in malignant pleural mesothelioma” and it was sponsored by the Mesothelioma Heroes Foundation of Chicago. The researchers wanted to test if tumor volume could be a good predictor of survival in pleural mesothelioma patients.
Over 6 years, researchers examined 116 patients who were receiving extended pleurectomy and decortication (EPD) surgery for pleural mesothelioma. Instead of using CT scans to estimate the volume of the patients’ tumors, the researchers measured the actual tumors after they were surgically removed.
To measure tumor volume, the researchers used the fluid displacement method. This method involves putting a solid object into a measured liquid and seeing how much the volume rises.
Current Staging Systems for Mesothelioma
There are currently three staging systems used for mesothelioma. All of these systems classify mesothelioma into 4 stages and none of them take volume or weight into account.
- The Butchart System – The Butchart System focuses on the location of the main tumor instead of the size or the number and spread of cancer cells. Dr. Eric Butchart developed this system in 1976 making it the first mesothelioma staging system.
- The Brigham System – This system focuses on the location, size, and spread of the cancer. This system was developed by Dr. David Sugarbaker while he was at Brigham and Women’s Hospital.
- TNM Staging System – The TNM system focuses on evaluating the tumor (T), the spread to the lymph nodes (N), and metastasis (M). This system was developed by the American Joint Committee on Cancer (AJCC).
The tumor/node/metastasis or TNM system is now the most commonly used system to stage cancer, including mesothelioma. The diagnosis of stage 1 through 4 is decided based on 3 categories represented by T, N, and M.
The categories are rated by the extent of cancer with X or a number 0 through 4. X means that category couldn’t be evaluated properly. Then 0-4 represent the severity of the cancer, 0 being the least cancer and 4 being the most.
- Tumor: This category evaluates the main tumor and how much it has grown and spread. TX means that the tumor can’t be assessed. Then the range of tumor growth can be measured from T0, meaning that there is no evidence of a main tumor, to T4, meaning the tumor has grown too far to be surgically removed.
- Node: This category evaluates whether the cancer has spread to the nearby lymph nodes and how much. NX means the lymph nodes cannot be assessed. N0 means there has been no spread to nearby lymph nodes. N3 is the highest rating which means that the cancer has spread to lymph nodes on the opposite side of the body from the main tumor.
- Metastasis: This category evaluates whether the cancer has spread to other organs. Metastasis is only evaluated as 0 or 1. M0 means that there has been no spread to distant organs or areas. M1 means the cancer has spread to distant organs or areas.