A Canadian study suggests that triple-modality therapy with radiotherapy, immunotherapy, and surgery may extend the lives of people with malignant pleural mesothelioma.
Pleural mesothelioma is an intractable cancer with a poor prognosis. It mainly affects people who have lived or worked around asbestos.
There is no cure for mesothelioma. People who have the best mesothelioma outcomes usually have a combination of treatments.
Now, scientists at Toronto General Hospital’s Research Institute say a triple-modality therapy they tested in mice might have the power to extend human lives, too.
Multi-modal Mesothelioma Treatment
Pleural mesothelioma is a fast-growing cancer that starts on the membrane around the lungs. Many mesothelioma patients die less than a year after diagnosis.
There is no single accepted treatment for mesothelioma Most patients start with chemotherapy. But this treatment rarely works by itself.
Doctors often combine several mesothelioma treatments to get the best results. Triple-modality therapy is therapy that uses three types or “modes” of treatment.
Mesothelioma treatments may also include immunotherapy, radiation, surgery, or other experimental therapies. Getting the right combination for each individual is key to long-term mesothelioma survival.
Perfecting Triple-Modality Therapy
The new study occurred at a research facility affiliated with Princess Margaret Cancer Centre.
At Princess Margaret, pleural mesothelioma patients usually receive radiotherapy followed by radical surgery. Radiotherapy helps reduce the size of the mesothelioma tumor. This makes it easier for surgeons to remove it.
Even with this aggressive treatment, many patients relapse. Others develop new mesothelioma tumors in other parts of the body. Researchers think a triple-modality therapy may improve on their protocol.
Immunotherapy to Enhance Radiation Treatment
One positive effect of radiation is that it stimulates the immune system. This can help fight mesothelioma. But mesothelioma cells release proteins that suppress the immune system.
The experimental triple-modality therapy adds targeted immunotherapy to the mix. One drug enhances the immune stimulating effects of radiation. Another drug helps counter immunosuppression. Then surgeons remove the mesothelioma tumor.
The treatment improved the effectiveness of radiotherapy in a mouse model of mesothelioma. It also created an abscopal response. This is when distant tumors are affected by treatment to one tumor. The next step is to test this triple-modality therapy in human mesothelioma patients.
“These data support the development of clinical trials in MPM to test such treatment options for patients with locally advanced or metastatic tumors,” the report concludes.
Murakami, J, et al, “Triple-modality therapy maximizes antitumor immune responses in a mouse model of mesothelioma”, April 14, 2021, Science Translational Medicine, Volume 13, Issue 589, https://stm.sciencemag.org/content/13/589/eabd9882