Abstract 173P
Background
Early-stage EGFR-mutated (EGFRmut) NSCLC is poorly characterized. This study analyzed clinical and pathological features in a Spanish cohort.
Methods
A retrospective review of resected EGFRmut stage I-III NSCLC cases was conducted in Hospital 12 de Octubre, with mutations identified by real time-PCR or NGS. Survival was analyzed using Kaplan-Meier and Cox models, and associations were tested with Chi-square and Fisher’s exact tests.
Results
Between April 2011 and January 2022, 76 NSCLC EGFRmut patients underwent curative-intent surgery. Median age was 70.5 years, 62% were women, 50% non-smokers, 74% had a performance status (PS) of 0.74% were stage I, 83% had common EGFRmut (51% exon 19 deletions, 32% exon 21 L858R) and 6.6% exon 20 insertions. PD-L1 was ≥1 in 27% and 50% had co-mutations (detected by NGS). Some 29 patients had additional malignancies before (53.6%) and after (46.4%) NSCLC diagnosis. After a median follow-up of 79.7 months, up to 22 patients (29%) had recurrences. The median disease-free survival (DFS) and overall survival (OS) were not reached (71% without relapse and 77.3 % alive). PS (PS 1–2 vs PS 0) and staging (stage II–III vs stage I) were associated with DFS (HR=5.02, CI: 2.09–12.03; HR=1.8, CI: 1.4–2.3 respectively) and OS (HR=6.2, CI: 2.5–15.3; HR=2.0, CI: 1.3–2.6 respectively) in univariable and multivariable analysis (DFS HR=3.3, CI: 1.15–9.52; HR=5.3, CI: 1.9–14.5; OS HR=6.2, CI: 1.99–19.57; HR=4.6, CI: 1.48–14.34 respectively). Furthermore, a correlation between tobacco exposure and PD-L1 expression was observed (p=0.002). Additional malignancy was correlated with PD-L1 expression (p=0.003) but not with tobacco (p=0.5). Additionally, co-mutations were more prevalent in L858R EGFRmut tumors (p=0.007).
Conclusions
This study describes a real-world early-stage EGFRmut NSCLC population with outcomes similar to those reported in the literature. Survival outcomes were significantly associated with cancer stage and PS. Moreover, our study reveals a high prevalence of additional neoplasms and suggests that tobacco exposure may affect PD-L1 expression in patients with early-stage EGFRmut NSCLC.
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.