TEMPORARY REMOVAL: Radiotherapy improves survival in Non-small cell lung cancer following oligoprogression on immunotherapy: A cohort study

Introduction:The patterns of oligoprogression following first-line immune checkpoint inhibitors (ICIs) for metastatic NSCLC are yet to be well established.There is increasing data to suggest directed radiotherapy improves survival outcomes in patients with progression following ICIs. Methods:A retrospective cohort study of patients with metastatic NSCLC who had progressed following first-line PD-(L)1 inhibitors +/-chemotherapy at two high-volume cancer centres was performed.We sought to characterise the frequency and location of oligoprogression and determine the overall survival (OS) following radiotherapy in this population.Results: One-hundred and fifty-nine patients were included in the study.At first progression, 62 (39.0%) were classified as oligoprogression.Multivariate analysis confirmed the presence of brain metastases was associated with increased likelihood of oligoprogression (OR 2.44; p=0.04) with most (63.2%) of these patients experiencing progression intracranially.The presence of liver metastases was associated with decreased likelihood of oligoprogression (OR 0.17; p<0.01).For patients with oligoprogression, those who received radiotherapy had a longer median PFS2 (17 vs. 11.5 months; HR 0.51; p=0.02) and a longer median OS (23 vs. 13 months; HR 0.40; p<0.001) compared to those who did not receive radiotherapy.No difference in PFS2 or OS outcomes was observed between patients who received radiotherapy versus those who did not for systemic progression. J o u r n a l P r e -p r o o fConclusions: In patients with oligoprogressive metastatic NSCLC following treatment with first-line ICIs, radiotherapy significantly improves OS and PFS2 outcomes.Patients with baseline brain metastases are more likely to experience oligoprogression.Further prospective studies in directed, less heterogenous populations of patients with metastatic NSCLC will be fundamental to optimise management.