Characterizing Metastatic Non-Small Cell Lung Cancer Presenting to an Academic Medical Center in an Era of Changing Treatment Paradigms

Purpose/Objective(s) Recent randomized trials have supported the existence of a limited metastatic disease state that may benefit from definitive local therapy in patients with non-small cell lung cancer (NSCLC). Due to limits of current staging systems, it is not possible to evaluate the spectrum of metastatic disease with commonly used cancer registries. The purpose of this study is to evaluate the extent and burden of metastatic disease in NSCLC patients presenting to an academic medical center and determine the incidence of patients meet existing criteria for ‘oligometastatic' disease. Materials/Methods An observational cohort of patients with de novo or recurrent metastatic NSCLC diagnosed from 2016 to 2019 were randomly sampled from a tumor registry. Patients were excluded if they did not receive any tumor directed therapy. Baseline demographic, staging, and treatment data were obtained from the registry and structured electronic health record (EHR) data. Manual chart review was performed to obtain details on metastatic presentation, local therapy, and progression. Definitions for oligometastatic disease were obtained from NRG LU002, MDACC Gomez et al., SINDAS and SABR COMET clinical trials. Results One hundred eight patients were evaluated with a median age of 68 years (range, 22 – 92) at initial diagnosis and median follow up of 23.5 months. 75% of patients (n=81) presented with de novo metastatic disease, while 25% (n=27) presented with recurrence. Histologies included adenocarcinoma (66%, n=71), squamous cell carcinoma (9%, n=10), and ‘other' (20%, n=22). Targetable mutations were present in 31% (n=34) of patients including EGFR (n=27) and ALK (n=2) and MET (n=6). 41% (n=48) of patients had a suspected malignant effusion present at the time of diagnosis. Common sites of metastases included lymph nodes (n=85, 79%), lungs (n=60, 56%), brain (n=49, 45%), and bone (n=48, 44%). 19% (n=21) presented with only one total metastatic tumor, 29% (n=31) with 2-3, 17% (n=18) with 4-5, 19% (n=21) with 6-10, and 16% (n=17) with 10+ tumors. 28% (n=30) of all patients were eligible for at least one oligometastatic NSCLC clinical trial, with 16% meeting eligibility for LU-002 (n=17), 19% for MDACC (n=22), 16% for SABR COMET (n=17), and 5% for SINDAS (n=5). Among those that met trial criteria for oligometastatic disease 40% (n=12) were treated with local therapy including surgery or radiation. Conclusion Most patients presenting with metastatic NSCLC to our institution had initial de novo metastatic presentation, multi-organ involvement, and adenocarcinoma histology. Roughly one third of patients were classified as oligometastatic using existing trial criteria. A minority of oligometastatic patients were treated with local therapy after metastatic diagnosis during the study period.