Stage IA-IIIA Research Articles

Neoadjuvant Osimertinib for the Treatment of Stage I-IIIA Epidermal Growth Factor Receptor-Mutated Non-Small Cell Lung Cancer: A Phase II Multicenter Study.

To assess the safety and efficacy of the third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor osimertinib as neoadjuvant therapy in patients with surgically resectable stage I-IIIA EGFR-mutated non-small cell lung cancer (NSCLC). This was a multi-institutional phase II trial of neoadjuvant osimertinib for patients with surgically resectable stage I-IIIA (American Joint Committee on Cancer [AJCC] V7) EGFR-mutated (L858R or exon 19 deletion) NSCLC (ClinicalTrials.gov identifier: NCT03433469). Patients received osimertinib 80 mg orally once daily for up to two 28-day cycles before surgical resection. The primary end point was major pathological response (MPR) rate. Secondary safety and efficacy end points were also assessed. Exploratory end points included pretreatment and post-treatment tumor mutation profiling. A total of 27 patients were enrolled and treated with neoadjuvant osimertinib for a median 56 days before surgical resection. Twenty-four (89%) patients underwent subsequent surgery; three (11%) patients were converted to definitive chemoradiotherapy. The MPR rate was 14.8% (95% CI, 4.2 to 33.7). No pathological complete responses were observed. The ORR was 52%, and the median DFS was 40.9 months. One treatment-related serious adverse event (AE) occurred (3.7%). No patients were unable to undergo surgical resection or had surgery delayed because of an AE. The most common co-occurring tumor genomic alterations were in TP53 (42%) and RBM10 (21%). Treatment with neoadjuvant osimertinib in surgically resectable (stage IA-IIIA, AJCC V7) EGFR-mutated NSCLC did not meet its primary end point for MPR rate. However, neoadjuvant osimertinib did not lead to unanticipated AEs, surgical delays, nor result in a significant unresectability rate.

Prognostic Impact and Clinical Features of Spread through Air Spaces in Operated Lung Cancer: Real-World Analysis.

Background and Objectives: Lung cancer is the leading cause of cancer-related deaths. Spread through air spaces (STAS) is an adverse prognostic factor that has become increasingly known in recent years. This study aims to investigate the impact of STAS presence on overall survival (OS) and disease-free survival (DFS) in patients with surgically resected stage IA-IIIA lung cancer and to identify clinicopathological features associated with STAS. Materials and Methods: This research involved 311 lung cancer surgery patients. The relationship between the presence of STAS in the patients' surgical pathology and OS and DFS values was examined. Clinicopathological features associated with the presence of STAS were determined. Results: There were 103 (33%) STAS-positive patients. Adenocarcinoma histological subtype, perineural invasion (PNI), and lymphovascular invasion (LVI) were significantly correlated with being STAS positive. STAS significantly predicted DFS and OS. One-year and five-year DFS rates were significantly lower in the STAS-positive group compared to the STAS-negative group (65% vs. 88%, 29% vs. 62%, respectively, p ≤ 0.001). Similarly, one-year and five-year OS rates were significantly lower in the STAS-positive group compared to the STAS-negative group (92% vs. 94%, 54% vs. 88%, respectively, p ≤ 0.001). In multivariate analysis, STAS was found to be an independent prognostic factor for both DFS and OS (HR: 3.2 (95%CI: 2.1-4.8) and 3.1 (95%CI: 1.7-5.5), p < 0.001 and <0.001, respectively). Conclusions: In our study, STAS was found to be an independent prognostic biomarker in operated stage IA-IIIA lung cancer patients. It may be a beneficial pathological biomarker in predicting the survival of patients and managing their treatments.

Circulating cell-free and extracellular vesicles-derived microRNA as prognostic biomarkers in patients with early-stage NSCLC: results from RESTING study

BackgroundFactors to accurately stratify patients with early-stage non-small cell lung cancer (NSCLC) in different prognostic groups are still needed. This study aims to investigate 1) the prognostic potential of circulating cell-free (CF) and extracellular vesicles (EVs)-derived microRNA (miRNAs), and 2) their added value with respect to known prognostic factors (PFs).MethodsThe RESTING study is a multicentre prospective observational cohort study on resected stage IA-IIIA patients with NSCLC. The primary end-point was disease-free survival (DFS), and the main analyses were carried out separately for CF- and EV-miRNAs. CF- and EV-miRNAs were isolated from plasma, and miRNA-specific libraries were prepared and sequenced. To reach the study aims, three statistical models were specified: one using the miRNA data only (Model 1); one using both miRNAs and known PFs (age, gender, and pathological stage) (Model 2), and one using the PFs alone (Model 3). Five-fold cross-validation (CV) was used to assess the predictive performance of each. Standard Cox regression and elastic net regularized Cox regression were used.ResultsA total of 222 patients were enrolled. The median follow-up time was 26.3 (95% CI 25.4–27.6) months. From Model 1, three CF-miRNAs and 21 EV-miRNAs were associated with DFS. In Model 2, two CF-miRNAs (miR-29c-3p and miR-877-3p) and five EV-miRNAs (miR-181a-2-3p, miR-182-5p, miR-192-5p, miR-532-3p and miR-589-5p) remained associated with DFS. From pathway enrichment analysis, TGF-beta and NOTCH were the most involved pathways.ConclusionThis study identified promising prognostic CF- and EV-miRNAs that could be used as a non-invasive, cost-effective tool to aid clinical decision-making. However, further evaluation of the obtained miRNAs in an external cohort of patients is warranted.

Abstract 5840: Identifying drug tolerant persister to neoadjuvant osimertinib in resectable non-small cell lung cancer harbouring EGFR mutations (NORA) via single-cell RNA sequencing

Abstract Introduction: Adjuvant osimertinib is the standard of care for resected, stage IB-IIIA non-small cell lung cancer (NSCLC) harboring activating epidermal growth factor receptor (EGFR) mutation. Yet, the role of neoadjuvant osimertinib is not clear. In the NORA trial (NCT04816838), we aimed to identify the drug tolerant persister (DTP) after neoadjuvant osimertinib for surgically resectable, EGFR-mutated stage IA-IIIA NSCLC. Methods: Patients harboring EGFR Exon 19 deletion or L858R at clinical stage IA-IIIA were given 80 mg of neoadjuvant osimertinib daily for two 28-day cycles followed by surgical resection and adjuvant osimertinib for 3 years. The key exploratory endpoint was to characterize the DTP via single-cell RNA sequencing (scRNA-seq) with pre and post-osimertinib samples. Results: We performed scRNA-seq on twenty-five patients enrolled at Yonsei Cancer Center from June 2021 to March 2022. Patients with stage IA (n=8, 32%), IB (n=7, 28%), IIA (n=4, 16%), IIB (n=4, 16%), and IIIA (n=2, 8%) were included. For EGFR mutation, exon 19 del and L858R accounted for 10 (40%) patients and 15 (60%) patients, respectively. The ORR (all partial response) was 44% (n=11), major pathologic response (MPR) rate was 24% (n=6), and pathologic complete response rate was 0%. ScRNA-seq revealed a total of 252,339 cells (60 clusters) annotated as epithelial cells (10 clusters), fibroblasts (7 clusters), immune cells (17 clusters), myeloid (15 clusters), endothelial cells (11 clusters) that showed distinct enrichment in post-osimertinib samples, non-MPR, and L858R subset. We found that a distint epithelial subset, namely EP8-AGER, identified as alveolar type 1 (AT1) cells was enriched in the non-MPR subset showing activation of Wnt, Hippo, and YAP/TAZ pathway. Pseudotemporal ordering of this cluster showed activation of signaling pathway for COL4A2/COL4A3 related to structural consistuent of extracellular matrix, and RTKN2 associated with NF-κB. In the fibroblast subset, the proportion of FB6-CD74 associated with chemokine activity and NF-κB was higher in the non-MPR and L858R group. In the myeloid subset, CD8-C1-GZMK identified as CD8+ T cells with activation/effector and cytotoxic signatures was also enriched in the post-osimertinib samples. Among macrophages, 3 clusters (annotated as SELENOP+, SPP1+, PLXDC2+) showed enrichment of cholesterol metabolism with activation of apolipoprotein E that promotes conversion of proinflammatory macrophages into anti-inflammatory phenotypes. Lastly, the proportion of EC9-LYZ, annotated as scavenging endothelial cells was higher in the non-MPR and L858R group. Conclusion: Neoadjuvant osimertinib resulted in the cellular reprogramming in the tumor microenvironment, notably AT1 epithelial cell which may lead to a loop between cancer cells and fibroblasts for the generation of DTP cells. Citation Format: Jii Bum (Joy) Lee, Su-Jin Choi, Young Joon Park, Kyoung-Ho Park, Seung Hyun Yong, Hyo Sup Shim, Byung Jo Park, Chang Young Lee, Min Hee Hong, Byoung Chul Cho, Sun Min Lim. Identifying drug tolerant persister to neoadjuvant osimertinib in resectable non-small cell lung cancer harbouring EGFR mutations (NORA) via single-cell RNA sequencing [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5840.

Validation of the 9th edition of the TNM staging system for non-small cell lung cancer with lobectomy in stage IA-IIIA.

The 9th edition of tumour-node-metastasis (TNM) staging for lung cancer was announced by Prof Hisao Asamura at the 2023 World Conference on Lung Cancer in Singapore. The purpose of this study was to externally validate and compare the latest staging of lung cancer. We collected 19193 patients with stage IA-IIIA non-small cell lung cancer (NSCLC) who underwent lobectomy from the Surveillance, Epidemiology and End Results database. Survival analysis by TNM stages was compared using the Kaplan-Meier method and further analysed using univariable and multivariable Cox regression analyses. Receiver operating characteristic curves were used to assess model accuracy, Akaike information criterion, Bayesian information criterion and consistency index were used to compare the prognostic, predictive ability between the current 8th and 9th edition TNM classification. The 9th edition of the TNM staging system can better distinguish between IB and IIA patients on the survival curve (P < 0.0001). In both univariable and multivariable regression analysis, the 9th edition of the TNM staging system can differentiate any 2 adjacent staging patients more evenly than the 8th edition. The 9th and the 8th edition TNM staging have similar predictive power and accuracy for the overall survival of patients with NSCLC [TNM 9th vs 8th, area under the curve: 62.4 vs 62.3; Akaike information criterion: 166182.1 vs 166131.6; Bayesian information criterion: 166324.3 vs 166273.8 and consistency index: 0.650 (0.003) vs 0.651(0.003)]. Our external validation demonstrates that the 9th edition of TNM staging for NSCLC is reasonable and valid. The 9th edition of TNM staging for NSCLC has near-identical prognostic accuracy to the 8th edition.

Application of a Comprehensive Model Based on CT Radiomics and Clinical Features for Postoperative Recurrence Risk Prediction in Non-small Cell Lung Cancer

We constructed a comprehensive model by combining the radiomics and clinical features of tumors to predict the recurrence risk of patients with operable stage IA-IIIA non-small cell lung cancer (NSCLC). Our aim was to improve the accuracy of prognostic prediction and provide personalized treatment plans to enhance patient outcomes. We retrospectively analyzed 152 surgically treated patients with pathologically confirmed stage IA-IIIA NSCLC. These patients were randomly divided into a training cohort and a test cohort in an 8:2 ratio. Using the 3D Slicer image computing platform, we manually delineated the regions of interest (ROI) for all lesions and extracted radiomics features using Python. We used the Least Absolute Shrinkage and Selection Operator (LASSO) to select the radiomics features, while the COX multivariate regression model was employed to identify independent clinical risk factors for recurrence. Finally, we utilized logistic regression (LR) to build the model and validated it using the receiver operating characteristic curve (ROC). The predictive performance of the model was evaluated using the concordance index (C-index), and the clinical value of the model was compared through decision curve analysis (DCA). We extracted a total of 1562 radiomics features. After feature selection, we retained 29 features. The COX multivariate regression model demonstrated that the N stage was an independent risk factor for postoperative recurrence. In the training and test cohorts, the area under the curve (AUC) values of the radiomics-clinical comprehensive model were 0.972 and 0.937, respectively, while the C-index values were 0.815 and 0.847. These values surpassed those of the standalone clinical model or radiomics model. Our study demonstrates that a comprehensive model based on CT radiomics and clinical features can effectively stratify the risk of postoperative recurrence in patients with operable NSCLC. It provides a powerful tool for accurately stratifying the risk of high-risk patients after surgery.

Intrinsic impacts of the expression of PD-L1 on postoperative recurrence in EGFR-mutated lung adenocarcinoma.

This study aimed to assess the intrinsic impacts of the expression of PD-L1 on postoperative recurrence and the prognosis in patients with epidermal growth factor receptor (EGFR)-mutated lung adenocarcinomas. Data from 221 surgically resected pathological stage IA-IIIA lung adenocarcinomas, collected between 2017 and 2019, were analyzed. This included measurements of EGFR mutations and the PD-L1 expression. Recurrence-free survival (RFS) and overall survival (OS) were estimated using a Kaplan-Meier analysis and log-rank test. The independent risk factors for RFS were assessed using univariate and multivariate analyses. Among the patients, 140 were PD-L1-negative (<1%), while 81 were PD-L1-positive (≥1%). PD-L1 positivity was significantly associated with male sex (p=0.038), smoking habit (p=0.005), ND2 lymph node dissection (p=0.013), higher malignant subtype (p=0.003), higher histological grade (p=0.001), and advanced pathological stage (p=0.004). Conversely, EGFR mutations were more common in the PD-L1-negative group than in the PD-L1-positive group (p=0.006). Patients were categorized into four groups based on their EGFR mutation status and PD-L1 expression status: PD-L1-positive (≥1%) with or without EGFR mutations (EGFR(+)/PD-L1≥1% or EGFR (-)/PD-L1≥1%), and PD-L1-negative (<1%) with or without EGFR mutations (EGFR(+)/PD-L1<1% or EGFR (-)/PD-L1<1%). Among these groups, EGFR(+)/PD-L1≥1% cases exhibited the worst 5-year RFS (log-rank, p=0.010), while there was no significant difference in 5-year OS (log-rank, p=0.122). Furthermore, a multivariate analysis revealed that PD-L1 positivity was an independent significant factor for RFS in EGFR-mutated lung adenocarcinoma (p=0.013). PD-L1 positivity emerged as an independent risk factor for RFS in patients with EGFR-mutant resected lung adenocarcinoma. These findings may provide valuable insights into the prognostic impact of PD-L1 expression and guide the implementation of postoperative adjuvant therapy in this patient population.

473P Treatment (tx) patterns in resectable stage IA–IIIA non-small cell lung cancer (NSCLC) in China: Subgroup analysis of a global real-world (rw) study

473P Treatment (tx) patterns in resectable stage IA–IIIA non-small cell lung cancer (NSCLC) in China: Subgroup analysis of a global real-world (rw) study

Heterogeneity of PD-L1 expression among resected EGFR-mutated NSCLC and prognostic implications.

143 Background: The predictive value of PD-L1 score to select patients for adjuvant immunotherapy among epidermal growth factor receptor (EGFR)-mutated non-small cell lung cancer (NSCLC) remains controversial, confounded by the use of different assays across trials. We sought to compare the concordance between 3 PD-L1 antibodies among resected EGFR-mutated NSCLC, evaluate intra-tumoral heterogeneity (ITH) and implications on survival outcomes. Methods: Tissue microarrays were constructed from patients with AJCC7 Stage IA-IIIA EGFR-mutated NSCLC who underwent surgery 1/1/2010 – 31/12/2019 at National Cancer Centre Singapore. Patients who received neoadjuvant therapy were excluded. Three 1mm tumor cores per patient were obtained to study ITH, defined as discordant tumor proportion score (TPS) in ≥2/3 cores. TPS was evaluated by 3 independent pathologists for 3 PD-L1 antibodies (SP263, SP142, 22C3) and analysed in tertiles of &lt;1%, 1-49% and ≥50%. Median TPS score across 3 cores for each pathologist per assay was used to assess concordance between assays with Cohen’s kappa test, which was also used to assess agreement between pathologists. Disease-free survival (DFS) and overall survival (OS) were tabulated using Kaplan-Meier method. Results: A total of 218 patients were included. Stage IA comprised 45%(99/218), IB 24%(53/218), II 17%(37/218) and IIIA 13%(29/218). Females made up 65%(142/218), never smokers 84%(183/218) and 71%(155/218) were acinar subtype adenocarcinomas. Ex19del was detected in 47%(103/218) and L858R in 39%(86/218). Distribution by PD-L1 TPS was 85%(185/218) vs 91%(198/218) vs 97%(212/281) for &lt;1%, 13%(28/218) vs 8%(17/218) vs 3%(6/218) for 1-49%, and 2%(5/218) vs 1%(3/218) vs 0% for ≥50%, using SP263, 22C3 and SP142 respectively (p&lt;0.001). Pairwise comparison of TPS scores revealed highest concordance between SP263 and 22C3 (Kappa 0.631), followed by 22C3 and SP142 (Kappa 0.361), and SP263 and SP142 (Kappa 0.192). Agreement between pathologists was excellent across all 3 assays, with median Cohen’s kappa of 1 (range 0.972 – 1). ITH was observed in 13%(29/218), with 5 patients having differing TPS scores in all 3 cores. Discordance was highest among TPS 1-49% at 96%(27/28), followed by ≥50% at 40%(2/5) and least among &lt;1% at 0% (p&lt;0.01). Compared to those with concordant TPS scores across all 3 cores, 5-year DFS (60% vs 47%, p=0.15) and 5-year OS (81%% vs 71%, p=0.043) were inferior for patients with ITH. Conclusions: Concordance of PD-L1 TPS was highest among SP263 and 22C3 and lowest for SP263 and SP142, with low inter-observer variability between pathologists. Heterogeneous PD-L1 expression within tumors was seen in 13% of patients and significantly correlated with inferior OS. Our findings support the relative interchangeability of SP263 and 22C3 among resected EGFR-mutated NSCLC but not SP142, while ITH in PD-L1 expression may represent a novel negative prognostic biomarker.

Elucidating the genomic and transcriptomic landscape of L858R vs ex19del EGFR-mutated NSCLC.

8530 Background: Epidermal growth factor receptor (EGFR)-mutated non-small cell lung cancer (NSCLC) is heterogeneous and L858R derive less benefit from osimertinib than ex19del in both the metastatic and adjuvant setting, which remains poorly understood. We sought to examine the genomic and transcriptomic features of L858R vs ex19del. Methods: Consecutive patients with AJCC7 Stage IA-IIIA EGFR-mutated NSCLC diagnosed 1/1/2010 – 31/12/2019 who underwent surgery at National Cancer Centre Singapore were included. Patients who received neoadjuvant therapy were excluded. Fresh frozen tumour and normal samples were subject to whole exome sequencing (WES) at 400X and 100X coverage respectively, with approximately 50 million paired-end reads for RNA-seq per sample. Wilcoxon and Fisher’s exact test were used for association analysis. Results: A total of 203 patients were included. Median age at diagnosis was 66, 66.0% (134/203) were females and 84.2% (171/203) never-smokers. Stage IA comprised 44.3% (90/203), IB 28.6% (58/203), II 15.8% (32/203) and IIIA 11.3% (23/203). Median tumour mutational burden (TMB) was 1.3 mutations/megabase (range 0.3 – 44.3). Ex19del represented 46.3% (94/203) and L858R 41.9% (85/203). Whole genome doubling (WGD) was found in 70.0% (142/203) and was more common in TP53-mutated compared to TP53-wildtype (81.1% vs. 63.6%, p=0.01). TP53 mutations were more common in stage II/IIIA tumours compared with stage IB and IA (50.9% vs 32.8% vs 30.0%, p=0.035). Comparing ex19del and L858R, there was no difference in stage distribution (p=0.337), proportion of TMB≥10 (1.1% vs 5.9%, p=0.103), number of cancer co-driver mutations (p=0.174), TP53 mutations (39.4% vs 32.9%, p=0.437) and WGD (69.1% vs 76.5%, p=0.316). L858R had a higher incidence of smoking mutational signature (median 0.35 vs 0.28, p=0.018) compared to ex19del despite similar smoking history (15.3% vs 12.8%, p=0.67), whereas APOBEC mutational signature was higher in ex19del (median 0.06 vs 0.04, p=0.015). L858R tumors were associated with a higher incidence of co-mutations in RBM10 (21.2% vs 6.38%, p=0.004), RNF213 (10.6% vs 1.06%, p=0.007) and amplification of NTHL1 (15.3% vs 2.13%, p=0.001) and AXIN1 (17.6% vs 3.19%, p=0.002) compared to ex19del. Transcriptomic subtype differed significantly by EGFR mutation with a higher representation of TRU subtype among L858R than ex19del (51.0% vs 35.3%, p=0.010), while GEP score was similar (median 0.189 vs 0.325, p=0.122). Conclusions: L858R have distinct co-mutations and copy number alterations compared to ex19del, in addition to a higher representation of smoking mutational signature and TRU subtype. TP53 co-mutations are more frequently observed in higher stage tumours and are associated with WGD. Our findings highlight the molecular heterogeneity of resected EGFR-mutated NSCLC, which could contribute to the differential outcomes to adjuvant osimertinib between ex19del and L858R.

Clinical and prognostic significance of detecting CEA, EGFR, LunX, c-met and EpCAM mRNA-positive cells in the peripheral blood, tumor-draining blood and bone marrow of non-small cell lung cancer patients.

Surgical treatment of early-stage non-small cell lung cancer (NSCLC) yields highest expectations for recovery. However, the frequency of further disease progression remains high since micro-metastatic disease may be undetected by conventional diagnostic methods. We test the presence and prognostic impact of circulating tumor cells (CTCs) in peripheral blood (PB), tumor-draining pulmonary blood (TDB) and bone marrow (BM) samples from NSCLC patients. The presence of circulating/disseminated tumor cells (CTCs/DTCs) was detected by quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) analysis in PB, TDB and BM samples before surgery in 119 stage IA-IIIA NSCLC patients (Clinical Trial NS10285). NSCLC patients with the presence of carcinoembryonic antigen (CEA) mRNA-positive CTCs/DTCs in TDB and BM had significantly shorter cancer-specific survival (CSS) (P<0.013, resp. P<0.038). Patients with the presence of epithelial cellular adhesion molecule (EpCAM) mRNA-positive CTCs in TDB samples had significantly shorter CSS and disease-free survival (DFS) (P<0.031, resp. P<0.045). A multivariate analysis identified the presence of CEA mRNA-positive CTCs in the PB as an independent negative prognostic factor for DFS (P<0.005). No significant correlation of CTCs/DTCs presence and other prognostic factors was found. In NSCLC patients undergoing radical surgery, the presence of CEA and EpCAM mRNA-positive CTCs/DTCs is associated with poorer survival.

Exhaled phospholipid transfer protein and hepatocyte growth factor receptor in lung adenocarcinoma

BackgroundScreening decreases mortality among lung cancer patients but is not widely implemented, thus there is an unmet need for an easily accessible non-invasive method to enable early diagnosis. Particles in exhaled air offer a promising such diagnostic tool. We investigated the validity of a particles in exhaled air device (PExA) to measure the particle flow rate (PFR) and collect exhaled breath particles (EBP) to diagnose primary lung adenocarcinoma (LUAD).MethodsSeventeen patients listed for resection of LUAD stages IA–IIIA and 18 non-cancer surgical control patients were enrolled. EBP were collected before and after surgery for LUAD, and once for controls. Proteomic analysis was carried out using a proximity extension assay technology. Results were validated in both plasma from the same cohort and with microarray data from healthy lung tissue and LUAD tissue in the GSE10072 dataset.ResultsOf the 92 proteins analyzed, levels of five proteins in EBP were significantly higher in the LUAD patients compared to controls. Levels of phospholipid transfer protein (PLTP) and hepatocyte growth factor receptor (MET) decreased in LUAD patients after surgery compared to control patients. PFR was significantly higher in the LUAD cohort at all timepoints compared to the control group. MET in plasma correlated significantly with MET in EBP.ConclusionCollection of EBP and measuring of PFR has never been performed in patients with LUAD. In the present study PFR alone could distinguish between LUAD and patients without LUAD. PLTP and MET were identified as potential biomarkers to evaluate successful tumor excision.

Quantitative Proteomics Indicate Radical Removal of Non-Small Cell Lung Cancer and Predict Outcome.

Non-small cell lung cancer (NSCLC) is associated with low survival rates, often due to late diagnosis and lack of personalized medicine. Diagnosing and monitoring NSCLC using blood samples has lately gained interest due to its less invasive nature. In the present study, plasma was collected at three timepoints and analyzed using proximity extension assay technology and quantitative real-time polymerase chain reaction in patients with primary NSCLC stages IA-IIIA undergoing surgery. Results were adjusted for patient demographics, tumor, node, metastasis (TNM) stage, and multiple testing. Major histocompatibility (MHC) class 1 polypeptide-related sequence A/B (MIC-A/B) and tumor necrosis factor ligand superfamily member 6 (FASLG) were significantly increased post-surgery, suggesting radical removal of cancerous cells. Levels of hepatocyte growth factor (HGF) initially increased postoperatively but were later lowered, potentially indicating radical removal of malignant cells. The levels of FASLG in patients who later died or had a relapse of NSCLC were lower at all three timepoints compared to surviving patients without relapse, indicating that FASLG may be used as a prognostic biomarker. The biomarkers were confirmed using microarray data. In conclusion, quantitative proteomics could be used for NSCLC identification but may also provide information on radical surgical removal of NSCLC and post-surgical prognosis.

PD-L1 score as a prognostic biomarker in asian early-stage epidermal growth factor receptor-mutated lung cancer

AimTo determine the prognostic value of programmed death-ligand 1 (PD-L1) score in early-stage epidermal growth factor receptor (EGFR)-mutated non-small cell lung cancer (NSCLC), contrasted against EGFR-wildtype NSCLC. MethodsConsecutive patients with Stage IA-IIIA NSCLC diagnosed 1st January 2010–31st December 2019 at National Cancer Centre Singapore with evaluable EGFR and PD-L1 status were included. Co-primary end-points were 2-year disease-free survival (DFS) and 5-year overall survival (OS) by Kaplan–Meier method. Results455 patients were included (267 EGFR-mutated, EGFR-M+; 188 EGFR-wildtype, wt). Median age at diagnosis was 65 years, 52.3% (238/455) of patients were males, 62.9% (286/455) of patients were never-smokers and 92.5% (421/455) of patients had R0 resection. Stage IA comprised 42.4% (193/455) of patients, Stage IB comprised 23.1% (105/455) of patients, Stage IIA comprised 10.8% of patients (49/455), Stage IIB comprised 5.1% of patients (23/455) and Stage IIIA comprised 18.7% (85/455) of patients. Among EGFR-M+, 45.3% (121/267) were Ex19del and 41.9% (112/267) were L858R. PD-L1 ≥1% among EGFR-M+ and EGFR-wt was 45.3% (121/267) and 54.8% (103/188) respectively (p = 0.047).At median follow-up of 47 months, 178 patients had relapsed. Among EGFR-M+, 2-year DFS comparing PD-L1 <1% and PD-L1 ≥1% was 78.1% and 67.6% (p = 0.007) while 5-year OS was 59.5% and 42.8% (p = 0.001), respectively. Controlling for age, gender, lymphovascular invasion, adjuvant therapy and resection margin status, PD-L1 ≥1% (hazard ratio, HR 2.18, 95% CI 1.04–4.54, p = 0.038), stage IIB (HR 7.78, 95% CI 1.72–35.27, p = 0.008) and stage IIIA (HR 4.45, 95% CI 1.44–13.80, p = 0.01) emerged as independent predictors of inferior OS on multivariable analysis.In exploratory analysis, genomic analysis of 81 EGFR-M+ tumours was performed. PD-L1 ≥1% tumours had significantly higher rates of TP53 mutations (36.1% versus 15.6%, p = 0.04), with predominantly missense mutations. ConclusionPD-L1 ≥1% is an independent predictor of worse OS among early-stage EGFR-mutated NSCLC and is associated with inferior DFS regardless of EGFR status. PD-L1 score as a risk stratification factor should be evaluated in prospective adjuvant studies among EGFR-mutated NSCLC.

933MO Longitudinal monitoring of circulating tumor DNA from plasma in patients with curative resected stage IA-IIIA EGFR mutant non-small cell lung cancer

For patients with early stage epidermal growth factor receptor mutation positive (EGFR-M+) non-small cell lung cancer (NSCLC), curative surgery followed by adjuvant chemotherapy is considered the standard of care. Recently, based on the ADAURA study, osimertinib was approved in resected stage IB-IIIA EGFR-M+ NSCLC. The circulating tumor DNA (ctDNA) provides a potential biomarker for detection of minimal residual disease (MRD) and recurrence. We investigated the longitudinal monitoring of ctDNA test in early stage EGFR-M+ NSCLC. Between August 2015 and October 2017, 278 patients with curative resected, stage IA-IIIA EGFR-M+ NSCLC were enrolled. Radiological follow-up was accompanied with longitudinal monitoring of ctDNA using a droplet digital PCR from baseline and follow-up per protocol until 5 years or recurrence. Median follow-up duration was 62.0 months (range, 1.5-774). Among 278 patients, stage IA, IB, IIA, IIB, and IIIA comprised 60.1%, 18.3%, 10.1%, 2.2%, and 9.4%, respectively. The EGFR exon 19 del was 60.1% and L858R was 39.9%. The 3-year DFS rate for each stage was 95%, 78%, 58%, 50%, and 32%, respectively. Among 278 patients, baseline ctDNA was detected in 67 (24.1%) patients: 23.4% (stage IA), 17.6% (IB), 17.9% (IIA), 50.0% (IIB), and 42.3% (IIIA) (P=0.06). In 76.1% (51 of 67) of patients with baseline ctDNA, it was cleared up 4 weeks after surgery. Patients were classified into three groups according to the positivity of ctDNA (Group A: baseline ctDNA negative (n=211), Group B: baseline ctDNA positive, but MRD negative (n=51), Group C: baseline ctDNA positive, but MRD positive (n=16)). The 3-year DFS rate was significantly different among the three groups (83.3% for Group A, 78% for Group B, and 50% for Group C, respectively, P=0.02). After adjusting for clinicopathologic variables, ctDNA group (HR 1.27, 95% CI 1.03-1.57, P=0.03) still remains an independent risk factor regardless stage for DFS. These results suggest that patients with baseline ctDNA positive or MRD positive were associated with poor DFS in curative resected stage IA-IIIA EGFR M+ NSCLC. Further detailed results of longitudinal monitoring of ctDNA and clinical recurrence will be presented.

Circulating T Cell Activation and Exhaustion Markers Are Associated With Radiation Pneumonitis and Poor Survival in Non-Small-Cell Lung Cancer.

IntroductionPersistent inflammation and immune activation in the lungs are associated with adverse outcomes such as radiation pneumonitis (RP) and poor survival in non-small-cell lung cancer (NSCLC) patients. However, it is unknown how this is reflected by leukocyte activation markers in serum.ObjectiveThe aim was to evaluate the serum levels of activation of different leukocyte subsets and to examine those in relation to the pathogenesis of RP and survival in NSCLC.MethodsWe analyzed the serum levels of MPO, sCD25, sTIM-3, sPD-L1, sCD14, sCD163, CCL19 and CCL21 in 66 inoperable NSCLC patients with stage IA-IIIA disease. The patients were treated with stereotactic body radiation therapy (SBRT) or concurrent chemoradiation therapy (CCRT), followed by regular blood sampling for 12 months after treatment and for 5 years for survival.ResultsNineteen (29%) patients developed RP, which occurred more frequently and earlier in patients receiving CCRT than in those receiving SBRT. Increases in sCD25, sTIM-3 and CCL21 levels were observed at the last 6 months of follow-up in patients who had RP after SBRT. Patients who had RP after CCRT had higher sTIM-3 levels during the first 3 months of follow-up. Baseline sCD25 was independently associated with both 2- and 5-year mortality outcomes, while baseline sTIM-3 was independently associated with 2-year mortality.ConclusionWe showed that T cell activation and exhaustion markers such as sCD25 and sTIM-3 are enhanced in patients developing RP and are associated with poor survival in NSCLC.

Treatment patterns and outcomes in resectable early stage NSCLC: Interim analysis of a global real-world study.

e18803 Background: Complete surgical resection is the preferred treatment for early stage NSCLC, with adjuvant chemotherapy as the standard of care in resected stage II/III and select stage IB NSCLC. Osimertinib, an epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI), is approved as adjuvant therapy in patients (pts) with resected stage IB–IIIA EGFR mutation-positive (EGFRm) NSCLC following results from the Phase III ADAURA trial. Understanding real-world clinical outcomes in early stage NSCLC, including EGFRm prevalence, will help inform unmet needs and further development of new treatment strategies in this population. We report interim results from a global non-interventional retrospective study of pts with resectable NSCLC using clinical data from medical records. Methods: Eligible pts (aged ≥18 yrs) had completely resected stage IA–IIIA NSCLC diagnosed between Jan 1, 2014 and Dec 31, 2017 with EGFR test results available and were followed to at least Dec 31, 2020. Primary endpoints included EGFRm prevalence, treatment patterns, and overall survival (OS); disease-free survival (DFS) was an exploratory endpoint estimated by Kaplan-Meier at predefined landmark timepoints. Results: Of 463 pts from 6 countries (31% from Taiwan, 21% Canada, 17% US, 13% Austria, 10% South Korea, 9% France), median age was 66 yrs (range: 33–86); 172 pts (37%) had stage IA NSCLC at initial diagnosis and 291 (63%) had stage IB–IIIA (22% IB, 13% IIA, 10% IIB, 18% IIIA). 213/463 pts (46%) were EGFRm (43% stage IA, 61% IB, 43% IIA, 26% IIB, 47% IIIA), of who 46% were from Taiwan, 21% South Korea, 14% Austria, 8% Canada, 7% US, and 4% France. In pts with EGFRm vs EGFR wild-type (wt) NSCLC, 84/213 (39%) and 83/250 (33%), respectively, received (neo)adjuvant therapy, of who 156/167 pts (93%) had stage IB–IIIA NSCLC. 106/156 pts (68%) had disease recurrence or death from time of surgery; recurrence rates were similar in pts with EGFRm vs EGFRwt NSCLC, though median DFS was longer in the EGFRm group (Table). Recurrence rates were high in both EGFRm and EGFTwt groups, with landmark DFS probability of 72% vs 77% at 12 mo and 29% vs 32% at 60 mo, respectively. Conclusions: In this real-world global study of surgically resected stage IA–IIIA NSCLC in pts who received an EGFR test, nearly half of the study cohort were EGFRm positive, of who 70% were treated in Taiwan/South Korea. The high rate of recurrence in pts with stage IB–IIIA NSCLC despite receiving (neo)adjuvant therapy reinforces the need for early diagnosis and EGFR testing to identify pts who might benefit from EGFR-targeted therapy, helping optimize clinical outcomes.[Table: see text]

PD-L1 score as a prognostic biomarker in Asian patients with early-stage, EGFR-mutated lung cancer.

8527 Background: Adjuvant Atezolizumab was recently approved in stage II-IIIA non-small cell lung cancer (NSCLC) with PD-L1 ≥1%. However, disease-free survival (DFS) benefit was mainly driven by PD-L1 ≥50% and among EGFR-mutated subgroup, atezolizumab did not demonstrate DFS benefit when PD-L1 0% patients were included. We sought to determine the prognostic value of PD-L1 score in early-stage EGFR-mutated NSCLC. Methods: Consecutive patients with Stage IA-IIIA NSCLC diagnosed 1/1/2010 – 31/12/2019 who underwent curative surgery at National Cancer Centre Singapore with evaluable EGFR and PD-L1 status were included. Co-primary endpoints were 2-year DFS and 5-year overall survival (OS) by Kaplan-Meier method. Results: 455 patients were included (267 EGFR-mutant; 188 EGFR-wildtype). Median age at diagnosis was 65 years, 52.3% (238/455) were males and 62.9% (286/455) were never-smokers. Adenocarcinomas comprised 92.1% (419/455) and 92.5% (421/455) had R0 resection. Stage IA comprised 42.4% (193/455), Stage IB 23.1% (105/455), Stage II 15.8% (72/455) and Stage IIIA 18.7% (85/455). Among EGFR-mutant, 45.3% (121/267) were Ex19del and 41.9% (112/267) were L858R. PD-L1 ≥1% among EGFR-mutant and EGFR-wildtype was 55.8% (149/267) and 60.1% (113/188) respectively (p = 0.361). PDL1 ≥50% was significantly associated with higher stage at diagnosis among EGFR-mutant (p &lt; 0.001) but not EGFR-wildtype (p = 0.319). At median follow up of 47 months, 178 patients had relapsed. Among EGFR-mutant, 2-year DFS comparing PD-L1 0% and PD-L1 ≥1% was 79.0% and 68.9% (p = 0.006) while 5-year OS was 87.6% and 70.6% (p = 0.006) respectively. 2-year DFS and 5-year OS by PD-L1 tertile (as shown in table) revealed that higher PD-L1 score was prognostically worse for both DFS and OS among EGFR-mutant. A similar trend was observed among EGFR-wildtype but did not reach statistical significance, apart from PD-L1 ≥50% which had significantly inferior DFS. Conclusions: Higher PD-L1 score was significantly associated with worse DFS and OS among early-stage EGFR-mutated NSCLC, possibly due to higher stage at diagnosis among PDL1 ≥50%. Our study highlights the poor prognosis of PDL1 ≥50% EGFR-mutated NSCLC in a pre-osimertinib era and underscores the importance of personalised risk-stratified adjuvant strategies. [Table: see text]

Surgical approach does not influence changes in circulating immune cell populations following lung cancer resection

IntroductionThe multimodal management of operable non-small cell lung cancer (NSCLC) continues to evolve rapidly. The immune milieu allowing for immunotherapeutic benefit can be affected by multiple parameters including clinicopathologic and genetic. Surgery induced physiological changes has received attention for modulating and affecting post-operative oncotaxis and immunosuppression. Here, we sought to investigate how surgical stress influences phenotype of peripheral blood mononuclear cells (PBMCs) in patients with NSCLC who underwent lobectomy. MethodsBlood was prospectively collected from patients with Stage IA-IIIA NSCLC undergoing lung resection between 2016 and 2018. Samples were obtained pre-operatively, 24 h and 4 weeks after surgery. PBMCs were isolated and subject to high-dimensional flow cytometry, analyzing a total of 115 cell populations with a focus on myeloid cells, T cell activation, and T cell trafficking. We further evaluated how surgical approach influenced post-operative PBMC changes, whether the operation was conducted in an open fashion with thoracotomy, or with minimally invasive Video Assisted Thoracoscopic Surgery (VATS). ResultsA total of 76 patients met the inclusion criteria (Open n = 55, VATS n = 21). Surgical resection coincided with a decrease in T lymphocyte populations, including total CD3+ T cells, CD8+ T cells, and T effector memory cells, as well as an increase in monocytic myeloid-derived suppressor cells (mMDSC). Post-operative changes in PBMC populations were resolved after 4 weeks. Surgical-induced changes in immune populations were equivalent in patients undergoing open thoracotomy and VATS. DiscussionSurgical stress resulted in transient reduction in T cells and T effector memory cells, and increase of mMDSC following resection in NSCLC patients. The immune profile modulation was similar regardless of surgical approach. These findings suggest that surgical approach does not seem to affect mononuclear cell lines obtained from peripheral blood. Thus, the decision regarding surgical approach should be patient centered, rather than based on post-operative treatment response optimization.

Relationship between 18F-FDG PET/CT Semi-Quantitative Parameters and International Association for the Study of Lung Cancer, American Thoracic Society/European Respiratory Society Classification in Lung Adenocarcinomas

ObjectiveTo investigate the relationship between 18F-FDG PET/CT semi-quantitative parameters and the International Association for the Study of Lung Cancer, American Thoracic Society/European Respiratory Society (IASLC/ATS/ERS) histopathologic classification, including histological subtypes, proliferation activity, and somatic mutations.Materials and MethodsThis retrospective study included 419 patients (150 males, 269 females; median age, 59.0 years; age range, 23.0–84.0 years) who had undergone surgical removal of stage IA–IIIA lung adenocarcinoma and had preoperative PET/CT data of lung tumors. The maximum standardized uptake values (SUVmax), background-subtracted volume (BSV), and background-subtracted lesion activity (BSL) derived from PET/CT were measured. The IASLC/ATS/ERS subtypes, Ki67 score, and epidermal growth factor/anaplastic lymphoma kinase (EGFR/ALK) mutation status were evaluated. The PET/CT semi-quantitative parameters were compared between the tumor subtypes using the Mann–Whitney U test or the Kruskal–Wallis test. The optimum cutoff values of the PET/CT semi-quantitative parameters for distinguishing the IASLC/ATS/ERS subtypes were calculated using receiver operating characteristic curve analysis. The correlation between the PET/CT semi-quantitative parameters and pathological parameters was analyzed using Spearman’s correlation. Statistical significance was set at p < 0.05.ResultsSUVmax, BSV, and BSL values were significantly higher in invasive adenocarcinoma (IA) than in minimally IA (MIA), and the values were higher in MIA than in adenocarcinoma in situ (AIS) (all p < 0.05). Remarkably, an SUVmax of 0.90 and a BSL of 3.62 were shown to be the optimal cutoff values for differentiating MIA from AIS, manifesting as pure ground-glass nodules with 100% sensitivity and specificity. Metabolic-volumetric parameters (BSV and BSL) were better potential independent factors than metabolic parameters (SUVmax) in differentiating growth patterns. SUVmax and BSL, rather than BSV, were strongly or moderately correlated with Ki67 in most subtypes, except for the micropapillary and solid predominant groups. PET/CT parameters were not correlated with EGFR/ALK mutation status.ConclusionAs noninvasive surrogates, preoperative PET/CT semi-quantitative parameters could imply IASLC/ATS/ERS subtypes and Ki67 index and thus may contribute to improved management of precise surgery and postoperative adjuvant therapy.