Characteristics and Survival Analysis of Synchronous Oligometastatic Non-Small Cell Lung Carcinoma

Introduction: Synchronous oligometastatic (SO) NSCLC has been increasingly recognized as a distinct entity. Recently, its definition has been clarified by consensus (Dingemans, AMC et al. J. Thorac. Oncol. 14(12), 2109-2119). Aims: Evaluate the characteristics of the patients with SO-NSCLC according to the new definition, their treatment and survival compared to multimetastatic (MM) NSCLC. Methods: Retrospective analysis of the clinical records of patients diagnosed with metastatic NSCLC at an oncological hospital from 2014 to 2019. Patients without PET/CT and cranial imaging were excluded. Data regarding demographics, histological and molecular results, staging, systemic and local radical therapy (LRT) and follow-up were collected and analysed. Results: From 233 patients included, 63,9% had MM-NSCLC, 29,2% had SO-NSCLC treated with palliative therapy and 6,9% were SO-NSCLC submitted to LRT. There was no significant difference in age, sex, performance status, histology or mutational status between the groups. The number of metastasis ranged from 1 to 3 in 1 to 2 organs in the LRT group. Surgery was the preferred LRT for the primary tumour (62,5%) and radiotherapy for metastatic sites (56,3%). Survival distributions in a log rank test were significantly different, p<0,001. Median survival for mm-NSCLC, so-NSCLC with palliative therapy and so-NSCLC with LRT was 9 (95% CI 6,96-11,05), 20 (95% IC 16,83-23,17) and 27 months (95% IC 23,57-30,43), respectively. Conclusion: LRT of so-NSCLC is associated with extended survival. Even when curative intent is not possible due to local and regional extent of the disease, so-NSCLC is linked with better outcomes.