ESTRO 38: Radical Hemithoracic Therapy in Patients With Mesothelioma
Patients with mesothelioma are twice as likely to survive for 2 years or longer if they are treated with a high dose of radiation to the affected side of the trunk, according to research presented by Minatel et al at ESTRO 38, the annual congress of the European Society for Radiotherapy & Oncology (ESTRO) (Abstract OC-0500).
The phase III study looked at patients whose cancers could not be completely resected, and the researchers said their findings have the potential to change treatment and outcomes for this group of patients.
The study was led by Marco Trovo, MD, Chief of the Radiation Oncology Department at University Hospital of Udine, Italy. He said, “There is an urgent need for more effective treatments for mesothelioma. Surgery can be given to these patients, but it is often impossible to remove all of the tumor. Patients with mesothelioma are sometimes given radiotherapy to help control their symptoms. However, radiotherapy has evolved dramatically in the last few years, so we wanted to see if it could now be used to prevent the cancer from spreading to nearby tissue, hopefully bringing improvements in survival.”
Study Methods
The study involved 108 patients with malignant pleural mesothelioma who were treated at the National Cancer Institute of Aviano, Italy, between 2014 and 2018. All patients underwent nonradical lung-sparing surgery, followed by chemotherapy.
Patients were randomly assigned 1:1 to receive radical hemithoracic radiotherapy or a more typical form of palliative radiotherapy. Hemithoracic radiotherapy consisted of radiation delivered to either the left or right side of the trunk, depending on where the tumor was located. This involved 25 treatments delivering a total dose of 50 Gy to the left or right side of the trunk, as well as an extra 60-Gy dose to the precise location of the tumor. In the patients receiving palliative radiotherapy, treatment consisted of 5 to 10 treatments delivering a total dose of 20 to 30 Gy to the precise location of the tumor.
Results
Median follow-up was 12.3 months. In patients who received radical hemithoracic radiotherapy treatment, 2-year overall survival was 58%; in the patients who received the palliative radiotherapy, 2-year overall survival was 28% (P = .003). Factors associated with increased survival at the multivariate analysis were radical hemithoracic radiotherapy (hazard ratio [HR] = 0.46) and epithelioid histology (HR = 0.33).
Around 20% of patients receiving radical hemithoracic radiotherapy suffered radiation pneumonitis. Other adverse events included weakness, nausea, and mild inflammation of the esophagus.
Dr. Trovo said, “This research shows a clear survival benefit in using this type of radiotherapy for [patients with] mesothelioma whose tumors can only partially be removed by surgery. We believe that this should be considered the new standard of care for these patients.”
Dr. Trovo hopes that even greater gains in survival could be made by treating patients with radiotherapy followed by targeted immunotherapy.
Disclosure: For full disclosures of the study authors, visit estro.org.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
