P26.01 Survival Impact of Adjuvant Postoperative Radiation Therapy (PORT) in Locally Advanced Thymic Carcinoma (TC): An Up-To-Date Meta-Analysis

Abstract

TC is a rare malignancy that often carries a poor prognosis. Surgery remains the primary curative therapeutic approach when feasible with chemotherapy and/or PORT used as adjuvant modalities in an attempt to improve patients’ outcomes. Published comparative studies have reported conflicting results for PORT. The benefit of adding PORT to other adjuvant modalities in Masaoka-Koga stages II&III TC remains controversial. The purpose of this meta-analysis is to evaluate the impact of adding PORT to surgery with or without chemotherapy on overall survival (OS) in patients with resected Masaoka-Koga stages II&III TC. A review of the medical literature was conducted using online databases. Inclusion criteria consisted of resected Masaoka-Koga stages II&III TC, English language, studies reporting OS with hazard ratios (HR) or Kaplan-Meier curves, and comparative studies reporting outcomes of patients that underwent PORT versus those that did not. Studies that combined stages II&III with other stages were allowed as long as the preponderance of the sample consisted mainly of stages II&III. Those that did not separate Thymoma and Thymic carcinoma were excluded. A meta-analysis was conducted using an inverse variance method with random-effects model. Eight retrospective series with a total of 4,321 patients were included and analyzed. Two studies reported data on stages II&III and one study reported on stages III&IV. Two studies reported data that included stages I through III and three studies reported data that included stages I through IV. The addition of PORT was found to significantly impact OS in patients with resected stage II&III TC (HR 0.78, 95%CI:0.68-0.88; I2=28%). This is the first meta-analysis to show that adding PORT to adjuvant therapies is associated with a survival benefit in a cohort of resected TC with a preponderance of Masaoka-Koga stages II&III.