The routine use of hemithoracic radiotherapy after neoadjuvant chemotherapy and extrapleural pneumonectomy should be discouraged in patients with malignant pleural mesothelioma, a new study published online ahead of print in the journal The Lancet Oncology has shown.1
According to the American Cancer Society, malignant mesothelioma is fairly rare in the United States, with about 3,000 individuals being diagnosed with the disease each year.2
Although postoperative hemithoracic radiotherapy has been used for the treatment of malignant pleural mesothelioma, this treatment modality has not been evaluated in a randomized trial.1
Therefore, researchers led by Professor Rolf A. Stahel, MD, President of the European Society for Medical Oncology (ESMO), sought to assess high-dose hemithoracic radiotherapy after neoadjuvant chemotherapy and extrapleural pneumonectomy.
For the international phase 2 trial, researchers enrolled 151 patients receiving neoadjuvant chemotherapy of resectable stage T1-3, N0-2, M0 malignant pleural mesothelioma.
Participants were assigned to receive cisplatin 75 mg/m2 plus pemetrexed 500 mg/m2 on day 1 every 3 weeks for 3 cycles and extrapleural pneumonectomy. Of the 151 patients, 113 underwent extrapleural pneumonectomy, of which 52 achieved an objective response and 96 achieved complete macroscopic resection.
Researchers then randomly assigned 54 patients who achieved complete macroscopic resection to receive either high-dose radiotherapy or no radiotherapy.
Results showed that median locoregional relapse-free survival after surgery was 7.6 months (95% CI, 4.5 – 10.7) in the no radiotherapy group and 9.4 months (95% CI, 6.5 – 11.9) in the radiotherapy group.
In regard to safety, the most common grade 3 or 4 adverse events during chemotherapy and surgery were neutropenia, anemia, and nausea or vomiting. During radiotherapy, the most frequent grade 3 or higher adverse effects were nausea or vomiting, esophagitis, and pneumonitis. Of note, 1 patient died as a result of radiotherapy-associated pneumonitis.
- Stahel RA, Riesterer O, Xyrafas A, et al. Neoadjuvant chemotherapy and extrapleural pneumonectomy of malignant pleural mesothelioma with or without hemithoracic radiotherapy (SAKK 17/04): a randomised, international, multicentre phase 2 trial [published online ahead of print November 1, 2015]. Lancet Oncol. doi: 10.1016/S1470-2045(15)00208-9.
- American Cancer Society. Malignant mesothelioma. American Cancer Society website. http://www.cancer.org/cancer/malignantmesothelioma/detailedguide/malignant-mesothelioma-key-statistics. Updated May 15, 2015. Accessed November 2, 2015.