Hello, everyone. Thank you for the opportunity to present our work entitled EGFR Mutations and PD-L1 Expression in Early-Stage Non-Small Cell Lung Cancer. I am from Barretos Cancer Hospital, Brazil. This is my disclosure. This work was sponsored by AstraZeneca. I'd like to thank all co-authors for their contribution for this work. Molecular classification dramatically changed the standard of care for non-small cell lung cancer patients. The discovery of actionable alterations and the advances on targeted therapies increased patient survival. However, the benefit of these advances are mostly restricted to metastatic cases. Although it has been described that the frequency of actionable alterations can be different in early-stage cases and metastatic cases, such as EGFR mutations. Although targeted therapies and immunotherapies are mostly widespread for advanced non-small cell lung cancer patients, these tailored treatments are moving forward to the adjuvant setting. Recently, ozimertinib was approved as adjuvant therapy for EGFR mutated patients. In addition, some immunotherapies were also approved for non-metastatic cases with no actionable alterations. Thus, we aimed to investigate the frequency of EGFR mutations and PD-L1 expression in an early-stage series of lung adenocarcinomas from Brazil. We started from 302 cases. In this case, we assessed the EGFR mutational status and the PD-L1 expression. Since this is a retrospective series, three techniques were employed for mutational analysis, NGS, Sanger sequencing, and COBAS. For PD-L1, we used immunohistochemistry only for suitable samples. Besides on descriptive analysis, we also associate the molecular features with clinical pathological data. For survival analysis, we employed Kaplan-Meier curves and Cox regression analysis, considering that as the major outcome for overall survival and disease relapse or progression for event-free survival. Most of our patients were female, self-reported as white. Most of them were exposed to tobacco, and approximately half of the patients were diagnosed at disease stage 3A. As expected, the greatest majority of the patients received curative treatment. The most common type of surgical resection was lobectomy, and more than a half of the patients did not progress after curative treatment. EGFR mutations were detected in 70% of the adenocarcinoma cases, and exome 19 and L858R were the most frequent mutations. The presence of EGFR mutations were associated with tobacco exposure, reaching audience ratio above 20 for an average smokers. In addition, EGFR mutated patients presented a better overall and event-free survival. PD-L1 expression was positive for 36% of the analyzed cases. Most of these positive cases presented intermediate TPS score, and about 30% presented TPS higher than 50%. PD-L1 positivity was associated with tobacco-exposed patients, loss of weight prior diagnosis, and later stage Z diagnosis, 2B and 3A. PD-L1 expression was not associated with overall survival, but patients with TPS higher than 50% presented lower event-free survival. In the adjusted analysis, non-white skin color and EGFR mutated patients presented better outcome. On the other hand, higher performance status at diagnosis presented lower overall survival. In conclusion, the frequency of EGFR mutations was 70%, and EGFR mutations were associated with no tobacco exposure, so never smokers, and better overall survival. PD-L1 expression was detected in 36.7% of all cases, and PD-L1 positive cases were associated with smokers and quitters, loss of weight at diagnosis, and more advanced disease stage.

EGFR mutations

PD-L1 expression

non-small cell lung cancer

adenocarcinoma

tobacco exposure