WEDNESDAY, May 1, 2019 (HealthDay News) -- For patients with malignant pleural mesothelioma (MPM), overall survival (OS) is significantly improved with radical hemithoracic radiotherapy (RHR) versus palliative radiotherapy (PR), according to a study presented at ESTRO 38, the annual meeting of the European Society for Radiotherapy and Oncology, held from April 26 to 30 in Milan.
Emilio Minatel, M.D., from the Centro di Riferimento Oncologico in Aviano, Italy, and colleagues compared OS for MPM patients treated with RHR versus PR after nonradical lung-sparing surgery and chemotherapy. A total of 108 patients were randomly assigned to receive either radiotherapy to the entire hemithorax excluding the intact lung plus a simultaneous boost to areas of gross disease or to PR to thoracotomy scars or the gross disease only.
After 64 events, the researchers found two-year OS rates of 58 and 28 percent in the RHR and PR arms, respectively, in the intention-to-treat analysis (P = 0.003). In multivariate analysis, factors associated with increased survival were RHR and epithelioid histology (hazard ratios, 0.46 and 0.33, respectively). Documented toxicities in the RHR arm included grade 5 pneumonitis (one patient), grade 3 pneumonitis (four patients), pulmonary embolism (four patients), and pericardial effusion (two patients). Four patients had late respiratory failure requiring oxygen.
"This research shows a clear survival benefit in using this type of radiotherapy for mesothelioma patients whose tumors can only partially be removed by surgery," a coauthor said in a statement. "We believe that this should be considered the new standard of care for these patients."