The impact of preoperative imaging strategies in EGFR-mutant non-small cell lung cancer (NSCLC): A multi-center retrospective review.

Abstract

e20655 Background: ADAURA demonstrated an overall survival (OS) benefit with adjuvant osimertinib in Epidermal Growth Factor Receptor mutant (EGFR-mut) non-small cell lung cancer (NSCLC). However, only 50% of patients underwent a preoperative brain MRI, and PET-CT rates were not reported. Concerns were raised that preoperative imaging rates were not consistent with real world practices, leading to patients being effectively “understaged.” There is limited data on real world rates of preoperative PET-CT and brain MRIs in patients with EGFR-mut NSCLC. Moreover, there is little reported data on the staging impact of preoperative PET-CT and brain MRI. We hypothesized that PET CTs and brain MRIs are performed in the majority of patients with EGFR-mut NSCLC who are evaluated for surgery and lead to detection of metastases missed by CT imaging alone. Methods: We retrospectively analyzed patients with EGFR-mut NSCLC who were evaluated for surgery at three academic New York hospitals between 2016-2021. EGFR-mut was defined as an EGFR exon 19 deletion or EGFR L858R mutation. Results: Between 2016 and 2021,109 patients with EGFR-mut NSCLC underwent preoperative evaluation. The median age was 70 (range: 43-89), and they were predominately female (74%). Forty-three percent of patients were Asian, and 58% of patients had a history of never smoking. Based on initial CT imaging, 71 patients (65%) were clinical stage 1, 16 patients (16%) were clinical stage 2, and 20 patients (19%) patients were clinical stage 3. Of the 109 total patients, 107 (98%) underwent a PET-CT and only 39 patients (36%) had a brain MRI. Of the 107 who had PET-CT, 16 patients (15%) were found to have Stage 4 disease. Of the 39 patients who had a brain MRI, 7 patients (18%) were found to have brain metastases. The use of both PET-CT and brain MRIs for patients evaluated for surgery upstaged 20 (18%) patients out of 109 patients to metastatic disease and resulted in 90 (83%) patients undergoing surgery. Conclusions: Our study demonstrates that in real world practice nearly all patients (97%) who were being evaluated for surgery underwent a PET-CT whereas only subset of patients (37%) had a brain MRI. The use of preoperative PET-CT and brain MRIs led to the detection of metastatic disease in 18% of total patients with EGFR-mut NSCLC. These findings underscore the critical role of comprehensive preoperative imaging. We strongly recommend that both a PET-CT and brain MRI are routinely preformed in all patients with EGFR-mut NSCLC prior to surgery to ensure accurate staging and optimize treatment planning. PET CT and brain MRI impact on staging patients with EGFR NSCLC evaluated for surgery. Patients evaluated for surgery 109 Patients who had a PET CT 107 (98%) Patients who had Brain MRI 39 (36%) Upstaged by PET-CT or Brain MRI to IV Disease 20 (18%)