Metastatic location of extensive stage small-cell lung cancer: implications for thoracic radiation.

Abstract

This study was designed to evaluate the role of thoracic radiotherapy (TRT) in a selected patient population with oligometastatic extensive stage small-cell lung cancer (ES-SCLC) without brain or liver involved. The underlying hypothesis was that TRT will improve outcomes in this favorable patient population. 305 patients were included in an institutional review board (IRB)-approved study, of which 105 received TRT after chemotherapy (ChT) and 200 received ChT alone. The survival outcomes were compared between ChT+TRT group and ChT-alone group in patients with oligometastasis without brain or liver involved and patients with brain/liver/multimetastasis, respectively. The 1-year, 2-year and 5-year overall survival (OS) for all patients were 60.3%, 23.9% and 1.6%, respectively. The addition of TRT significantly improved PFS in total patients than ChT alone (14.5months vs. 10.1months, p = 0.006), but the OS benefit was not significant (17.8months vs. 16.5months, p = 0.061). For patients with oligometastasis (n = 118), TRT offered significant progression free survival (PFS) (16.5months vs. 9.1months, p = 0.005) and OS (19.2months vs. 15.6months, p = 0.039) benefits. However, for patients with brain/liver/multimetastasis, the PFS and OS were not improved with TRT (p = 0.49, p = 0.811). TRT provided significant PFS and OS benefits in patients with oligometastatic ES-SCLC without brain or liver involved. The consolidative TRT is a reasonable treatment option for this favorable patient population.