SMART, the acronym for surgery for mesothelioma after radiation therapy, is a groundbreaking protocol of treatment. Impressive life expectancy of 3-4 years should garnet more consideration for SMART for mesothelioma.
One idea is to add immunotherapy after surgery – a protocol called “SMARTEST.”
New research published in Physician’s Weekly shows how immunotherapy should be used on a case-by-case basis.
The study looked at the tumor microenvironment for cases following SMART protocol. Each patient received radiation before extrapleural pneumonectomy surgery. The intent of this approach is to shrink tumors before aggressive surgery. The idea originated from Princess Margaret Cancer Centre in Toronto and now is at Michigan Medicine, under Dr. Elliot Wakeam.
There were 69 patients whose microenvironment were the subjects of analysis following SMART. Around 75% of them were considered PD-L1-negative – meaning they did not express the protein PD-L1 any further. One-fourth did express this protein, which is cancer-enabling and suppresses the immune system’s T cells.
PD-L1 expression impacted survival. Biphasic cases with PD-L1 expression had a median survival of less than six months. Biphasic mesothelioma without PD-L1 expression had a median survival of 18 months.
Immune checkpoint inhibitors, which are a type of immunotherapy, block PD-L1 activity. Using these drugs (Opdivo/nivolumab and Keytruda/pembrolizumab) on PD-L1 cases may help survival after SMART.
Doctors also looked at the volume of CD8+ tumor-infiltrating lymphocytes (TILs). A larger number of CD8+ TILs led to longer survival, especially in epithelioid mesothelioma:
- 43 months median survival for CD8+ TILs equal to or greater than 2%
- 27 months median survival for CD8+ TILs less than 2%
The data indicates SMARTEST should be considered for epithelioid or biphasic cases of mesothelioma with PD-L1 expression.
Sources & Author
- Tumor Microenvironment After Hypo fractionated Radiation and Surgery for Mesothelioma. Physician’s Weekly. Retrieved from: https://www.physiciansweekly.com/tumour-microenvironment-after-hypo-fractionated-radiation-and-surgery-for-mesothelioma. Accessed: 01/12/2021.
Sources & Author