Predicting Unresectable Mesothelioma Prior to Surgery

Cancer researchers at Baylor have found an effective way to identify certain cases of unresectable mesothelioma without making an incision.

They focused on a common reason a surgeon might decide not to operate, even after the patient is on the table. The condition, called DCWI, is hard to identify without opening the patient up. 

But the Baylor team says there is a non-invasive way to identify DCWI and predict cases of unresectable mesothelioma. If it works, it could save patients the pain of surgery. It could also save lives by allowing doctors to start other mesothelioma treatments sooner. 

Diffuse Chest Wall Invasion in Mesothelioma

Diffuse chest wall invasion (DCWI) is a condition that can make it impossible to perform effective mesothelioma surgery.

DCWI means the mesothelioma tumor has spread to or “invaded” the wall of the chest. When mesothelioma is widespread on the chest wall, it is “diffuse”. DCWI is not easy to spot with imaging studies. Surgeons usually discover DCWI when they open the chest to do mesothelioma surgery.

Too much cancer on the chest wall results in unresectable mesothelioma. Surgeons have to close the patient back up and choose a different type of therapy. Unfortunately, by the time this happens, the patient may have lost valuable treatment time. 

Predicting Unresectable Mesothelioma by Finding DCWI

The Baylor researchers wanted to find out if there were preoperative variables associated with DCWI. If there were variables, they wanted to see if they could be measured.  

The group conducted a retrospective study using the medical records of 170 pleural mesothelioma patients. Patients were slated for mesothelioma surgery at Baylor between 2014 and 2018. 

One-hundred-and-four patients had lung sparing PD surgery. Thirty-nine patients underwent EPP surgery. The remaining 27 patients who went under the knife were found to have unresectable mesothelioma. In 24 patients, this was because of DCWI. The other three patients had cancer in some of their organs. 

The researchers found that the amount of space inside the patients’ rib cage – also called thoracic cage volume – was linked to DCWI. Thoracic cage volume can be measured with a CT scan.

“In univariable analysis, decreased ipsilateral thoracic cage volume demonstrated the strongest association with unresectability by DCWI,” writes study author Bryan Burt, MD. 

Dr. Burt says patients with more than a  5% decrease in thoracic cage volume were most likely to be inoperable.

Applying the Findings in Mesothelioma Management

Dr. Burt and his colleagues say watching for a decrease in thoracic cage volume may be a safer, easier way to predict unresectability. There are many potential advantages to finding unresectable mesothelioma without having to operate. 

“Preoperative identification of DCWI will avoid unnecessary thoracotomy [chest wall incision] and accelerate initiation of nonsurgical therapy in malignant pleural mesothelioma,” they write. 

The team is calling for further studies to validate the finding. 

Source:

Burt, B, et al, “Preoperative prediction of unresectability in malignant pleural mesothelioma”, November 27, 2019, Journal of Thoracic and Cardiovascular Surgery, Epub ahead of print, https://www.jtcvs.org/article/S0022-5223(19)33489-0/abstract