Characterization of Metastatic Non-Small Cell Lung Cancer and Oligometastatic Incidence in an Era of Changing Treatment Paradigms

Abstract

Because of the limitations of current staging systems and evolving definitions, there are limited data on oligometastatic non-small cell lung cancer (NSCLC) epidemiology. The purpose of this study was to evaluate metastatic disease burden and the incidence of oligometastatic disease using recent clinical trial eligibility criteria. A cohort of patients with metastatic NSCLC, diagnosed from 2016 to 2019, were randomly sampled from a curated tumor registry. Definitions for oligometastatic disease were obtained from relevant clinical trials. The Stanford Cancer Institute Research Database was used to identify baseline patient factors, systemic and local therapy, extent and location of metastatic lesions, and survival outcomes. Among 120 patients presenting with metastatic NSCLC, the majority had de novo metastatic disease (75%) with a median of 4 metastatic lesions involving 3 organ systems. Of these, 37.5% would have been eligible for at least 1 oligometastatic trial, with 28.3% meeting criteria for the MD Anderson Cancer Center trial, 20.0% for NRG-LU002, 6.7% for SINDAS, and 16.7% for SABR-COMET. By adding malignant pleural effusions and early progression as exclusionary criteria, only 54.1% of patients with ≤3 synchronous metastases were eligible for consideration of local therapy. Early progression on systemic therapy was associated with worse survival (10.0 vs 42.4 months; P < .001), whereas presence of malignant pleural effusions was not. Of those tumors identified as oligometastatic, 44.4% received local therapy and 28.9% underwent ablative therapy to all sites. There was a trend toward greater overall survival (44.4 vs 24.9 months; P=.055) and progression-free survival (8.0 vs 5.4 months; P=.06) in patients meeting eligibility for at least 1 oligometastatic trial. Around 48% of patients with metastatic NSCLC had ≤3 metastases at presentation and 28% met clinical trial criteria for oligometastatic disease. Future research is needed to better define the oligometastatic state and identify patients most likely to benefit from local therapy.