Non-small Cell Lung Cancer Patients Harboring EGFR Mutations Research Articles

Revealing distinct immune landscape in EGFR mutant and EGFR wild type lung adenocarcinoma by using single-cell RNA sequencing.

e21008 Background: Non-small cell lung cancer (NSCLC) with EGFR mutations displays heterogeneity in the extent of intratumoral immunocytes infiltration compared to those with EGFR wild types, which may explain their variable responsiveness to PD-1 blockade. Here, we performed single-cell RNA sequencing (scRNA-seq) to unveil the immunescape and heterogeneity of lung adenocarcinoma (LUAD) between EGFR mutant (EGFR-mut) patients and wild type (EGFR-wt) patients. Methods: Eleven EGFR-mut and 7 EGFR-wt NSCLC tumor samples were analyzed. Immune cells (CD45+) were enriched through fluorescence-activated cell sorting (FACS) and subjected to single-cell RNA sequencing (scRNA-seq) using the 10X Genomics platform. Sequencing reads were normalized and analyzed using the R/Seurat package. Cellular components of each sample were determined based on known marker genes. Wilcox test was used to compare promotion by subtype composition and immune cell infiltrates. Results: Different immune cell compositions were observed between EGFR-mut and EGFR-wt LUAD tumor samples. We found EGFR-wt tumors are marked by an enrichment of CCL15+ tumor-associated macrophages(TAMs), which display pro-inflammatory properties and high expressions of TNF-a-signaling genes. In contrast, EGFR-mut tumors exhibit enrichment of SPARCL1+TAMs, which are involved in epithelial-mesenchymal transition (EMT) and angiogenesis. EGFR-wt tumors exhibited enrichment of CD8-Teff-MX1 and Gamma delta T cells, both of which displayed higher cytotoxic and naive features. Moreover, the high expression of Gamma delta T corresponds with a better clinical prognosis. In contrast, CD8-Teff-XCL1 and NKT-FGFBP2 were found enriched in EGFR-mut tumors, both of which contributed to higher exhaustion and decreased cytotoxic function. Additionally, NK-IL32 was found enriched in EGFR-mut tumors, showing a downregulated T cell receptor signaling and stronger exhausted features. The high expression of this subcluster correlated with poor outcomes in LUAD patients harboring EGFR mutation. Conclusions: Our study provided a deeper understanding of the immune landscape of EGFR-mut and EGFR-wt LUAD and gained better insights into the immunological mechanisms involved in the response to ICIs. The results of our study could be instructive for the development of future immunotherapy strategies for NSCLC patients harboring EGFR mutations.

Abstract 2232: The identification of novel autophagy flux-related molecules closely linked to the acquired resistance to EGFR TKIs in NSCLC patients harboring EGFR mutations

Abstract Introduction: Non-small cell lung cancer (NSCLC) patients with activating EGFR mutations (mEGFR) well respond to EGFR TKIs, but the majority of patients eventually acquire drug resistance, leading to treatment failure. Recently, intracellular potential autophagy in addition to primary genetic alterations implicates the acquired drug resistance to targeted drugs in various carcinomas such as melanoma, pancreas, and breast cancer. We aimed to identify autophagy flux-related signal molecules which may be closely linked to acquired resistance in mEGFR NSCLC. Methods: We constructed the TMA composed of 579 surgically resected tumor tissues from lung adenocarcinoma patients and evaluated protein expression of autophagy flux-related signal molecules including CAGE, p-Beclin1, LC3B, p-AMPK, ULK1, p62, and ATG5 using immunohistochemistry (IHC). We established H1975OSI (166-folds) and PC9ERL (3,650-folds) resistant sub cell lines through the prolonged exposure of Osimertinib and Erlotinib to H1975 (L858R/T790M) and PC9 (Del19) cells, respectively. We also explored genes that induce autophagy flux activity using mRNA seq and qRT-PCR. Results: H-score of CAGE ( 95.6±7.9, 70±5.5), p-AMPK (73.4±7.8, 32±5.6) and p-Beclin1 (44.4±16.1, 19.7±5.5), ULK1( 57.4±4.9, 41.9±4.9) were significantly higher in mEGFR, compared to those of wild type EGFR NSCLC (P <0.001). According to EGFR mutation subtype, the expressions of CAGE (98±11.2, 70±5.5) and ULK1(60.7±5.0, 41.9±4.9) were significantly higher in Del19 (P<0.001), while the expressions of CAGE(93.2±5.6, 70±5.5,), p-AMPK(82.9±5.7, 32±5.6), and p-Beclin1(45.6±16.7, 19.7±5.5) were significantly higher in L858R (P<0.001). In advanced/metastatic mEGFR NSCLC patients treated with EGFR TKIs, p-Beclin1(13.0±10.9, 59±7.2) expression was significantly increased, when comparing before treatment and at treatment failure (P<0.018). As results of mRNA seq and qRT-PCR in H1975 parental cells and H1975OSI cells, we identified autophagy flux-related signal molecules including BECLIN1, GABAR1, NBR1, PINK1, ULK1 which were significantly increased more than 10 times. Conclusion: Taken together, our results strongly support the evidence that autophagy flux-related signal molecules as well as known genetic alterations are closely connected to the acquired resistance during period of EGFR TKI treatment in mEGFR NSCLC patients. Now, we are undergoing additional RNA profiling and function study of identified novel autophagy-related genes to examine a possibility as potential target to overcome EGFR TKI resistance. Citation Format: Jeong-Oh Kim, Jung-Young Shin, Min-Young Kim, Mi-Ran Lee, Seoree Kim, Hankyu Lee, Doyong Jeon, Seung Ryel Baek, Kim Joo Il, Kyoungjune Lee, Youn Soo Lee, Jin-Hyoung Kang. The identification of novel autophagy flux-related molecules closely linked to the acquired resistance to EGFR TKIs in NSCLC patients harboring EGFR mutations [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2232.

ARID1A deficiency reverses the response to anti-PD(L)1 therapy in EGFR-mutant lung adenocarcinoma by enhancing autophagy-inhibited type I interferon production

IntroductionEGFR mutations in non-small cell lung cancer (NSCLC) are associated with a poor response to immune checkpoint inhibitors (ICIs), and only 20% of NSCLC patients harboring EGFR mutations benefit from immunotherapy. Novel biomarkers or therapeutics are needed to predict NSCLC prognosis and enhance the efficacy of ICIs in NSCLC patients harboring EGFR mutations, especially lung adenocarcinoma (LUAD) patients, who account for approximately 40–50% of all NSCLC cases.MethodsAn ARID1A-knockdown (ARID1A-KD) EGFR-mutant LUAD cell line was constructed using lentivirus. RNA-seq and mass spectrometry were performed. Western blotting and IHC were used for protein expression evaluation. Effects of 3-MA and rapamycin on cells were explored. Immunofluorescence assays were used for immune cell infiltration examination.ResultsARID1A expression was negatively associated with immune cell infiltration and immune scores for ICIs in LUAD with EGFR mutations. In vitro experiments suggested that ARID1A-KD activates the EGFR/PI3K/Akt/mTOR pathway and inhibits autophagy, which attenuates the inhibition of Rig-I-like receptor pathway activity and type I interferon production in EGFR-mutant LUAD cells. In addition, 3-MA upregulated production of type I interferon in EGFR-mutant LUAD cells, with an similar effect to ARID1A-KD. On the other hand, rapamycin attenuated the enhanced production of type I interferon in ARID1A-KD EGFR-mutant LUAD cells. ARID1A function appears to influence the tumor immune microenvironment and response to ICIs.ConclusionARID1A deficiency reverses response to ICIs in EGFR-mutant LUAD by enhancing autophagy-inhibited type I interferon production.4p38v18Tik7_Gskdth_SehVideo

Associated factors for poor response in advanced EGFR-mutated NSCLC patients under tirosine kinasa inhibitors: Peruvian real-world data.

e21214 Background: Although tirosine kinasa inhibitors (TKI) are the first line of therapy in patients with non-small cell lung cancer (NSCLC) harboring EGFR mutations, some patients do not have benefit with TKI. The aim of this study is to determinate if there are associated factors with poor response with TKI. Methods: This is an observational study of a single institution patient cohort. Clinical records of advanced NSCLC patients harboring EGFR mutations that have received TKI as first line therapy in ALIADA cancer center since january 2015 until december 2019 were evaluated. Clinical records with incomplete data were excluded. Type of EGFR mutation, type of TKI agent, BMI, neutrophil, lymphocyte, platelets, neutrophil/lymphocyte ratio (NLR) and platelet/lymphocyte ratio (PLR) were evaluated in all cases. Poor responders where defined as NSCLC patients who progressed within 3 months with erlotinib or afatinib and 6 months within osimertinib. The statistical analysis was performed with SPSS version 20 and MINITAB 14. Results: 46 patients were finally included. Mean age was 63.6 ± 11.7 years, 54.4% of patients were female and 93% had adenocarcinoma histology. Mean neutrophil, lymphocyte and platelet counts were 4.82, 1.96 and 396.07 respectively; meanwhile mean NLR was 4.85 and mean PLR 282.36. 45% of patients were overweight or obese. 65.2% of all mutations were EGFR exon 19 deletions, 19.6% were exon21 L858R substitution and 10% EGFR uncommon mutations (de novo exon20 T790 mutations and exon18 G719X substitution). 45.7% of patients received erlotinib, 37% received afatinib and 17.3% osimertinib. 61.5% of patients achieved partial response, 17.3% achieved complete response, 9.6% stable disease and 28.3% of patients were poor responders to TKI treatment. In bivariate analysis, odds ratio for poor response was more associated with uncommon mutations (OR = 8.21, IC95% = 1.94-97.18; p = 0.025) and patients with neutrophil > 4.82 (OR = 1.65, IC 95% = 1.08-2.52; p = 0.020). Odds ratio for poor response decreases 95% with erlotinib (OR = 0.05, IC95% = 0.00-0.58; p = 0.016). There was no statistical association with the rest factors. In the logistic regression model, poor response to TKI are related to uncommon EGFR mutations (OR = 8.21, 95% CI = 1.3-51.99; p = 0.009) and neutrophils > 4.82 (OR: 1.85, 1.13 -3.05). Conclusions: Disease progression is a phenomenon present in patients with EGFR-mutated NSCLC. According to our data, poor response is associated with uncommon EGFR mutations, TKI agent (erlotinib) and neutrophil count level. We need larger studies to validate our results.

P76.53 Impact of Neutrophil-to-Lymphocyte Ratio in Patients with EGFR-Mutant NSCLC Treated with Tyrosine Kinase Inhibitors

We previously reported that a patient’s smoking status was an independent predictor of progression-free survival (PFS) in gefitinib and erlotinib therapy for patients with non-small cell lung cancer (NSCLC) harboring EGFR mutations. However, other indicators that can elaborate on the clinical efficacy to the EGFR-TKI therapy remain understudied. The inflammatory indicator neutrophil-to-lymphocyte ratio (NLR) in peripheral blood serves as a predictive factor for NSCLC patients treated with anti-cancer agents such as cytotoxic drugs and PD-1 inhibitors. Here, we aimed to evaluate the correlation between NLR and clinical efficacy of EGFR-TKIs in NSCLC patients harboring EGFR mutations. We retrospectively collected information of 205 patients with advanced NSCLC harboring exon 19 deletion or L858R point mutation and receiving gefitinib or erlotinib, between March 2009 and June 2016, were enrolled. The date cut-off date was March 2019. The clinical outcomes in the NSCLC patients were evaluated based on NLR level before EGFR-TKI therapy. Variables (including gender, age, performance status [PS], NLR, EGFR genotype, smoking status, clinical stage prior to EGFR-TKI treatment [Stage IV vs. postoperative recurrence], the presence or absence of brain metastases, type of EGFR-TKI [gefitinib vs. erlotinib]) were entered into a Cox proportional hazards regression model to estimate the hazards ratios for PFS and overall survival (OS). We used PFS longer or shorter than 10 months as the binary variables for ROC curves. The patient cohort comprised of 60% women, with 70 years median age, and 65% of good PS. An optimal cut-off value of 3.55 was chosen for NLR, with an area under the curve (AUC) value of 0.67 [95% confidence interval (CI): 0.59–0.74, P < 0.0001]. The response rates in the low-NLR and high-NLR groups were 69.2% (95% CI: 60.3–78.1%) and 51.5% (95% CI: 41.8–61.2%). In addition, the mean values of NLR in responders (patients with partial response) and non-responders (patients with stable disease or progressive disease) were 4.8 and 11.3 respectively, indicating a significant difference (P = 0.021). A median follow-up period for the survival analysis was 25.2 months. The median PFS and OS of all the patients together were 10.8 months (95% CI: 8.8– 12.8 months) and 28.0 months (95% CI: 23.5– 32.5 months). The median PFS in the low-NLR and high-NLR groups were 15.7 months (95% CI: 12.7–18.7 months) and 6.7 months (95% CI: 4.6–8.8 months). The median OS in the low-NLR and high-NLR groups were 37.6 months (95% CI: 30.3–44.9 months) and 19.2 months (95% CI: 10.6–27.8 months). The multivariate analysis identified PS, NLR, stage, and smoking status as independent predictors of PFS. Moreover, the PS and NLR were identified as independent predictors of OS. NLR was a significant predictor of clinical efficacy in NSCLC patients harboring EGFR mutations treated with gefitinib or erlotinib.

Soluble PD-L1 as a Predictor of the Response to EGFR-TKIs in Non-small Cell Lung Cancer Patients With EGFR Mutations.

Programmed cell death ligand 1 (PD-L1) expressed on tumor tissues is a vital molecule for immune suppression and its impact on the response to epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) has been reported. The significance of soluble PD-L1 (sPD-L1) for lung cancer patients remains unknown. This study investigated whether sPD-L1 could predict the response of EGFR-mutated non-small cell lung cancer (NSCLC) to EGFR-targeted therapy. We retrospectively evaluated patients who received first-line treatment with EGFR-TKIs for advanced NSCLC with EGFR mutations. Pre-treatment plasma concentrations of PD-L1 and on-treatment (1 month after treatment initiation) plasma concentrations of PD-L1 were measured using the R-plex Human PD-L1 assay. The association between the sPD-L1 level and the clinical outcome was analyzed. Among 66 patients who were eligible for the study, patients with high pre-treatment or on-treatment sPD-L1 levels had decreased objective response rate (ORR) compared with that of patients with low sPD-L1 levels (39.4 vs. 66.7%, p = 0.026 for pre-treatment sPD-L1 level, and 43.5 vs. 73.9%, p = 0.025 for on-treatment sPD-L1 level). A high baseline sPD-L1 level was associated with a shortened progression-free survival (PFS) rate (9.9 vs. 16.1 months, p = 0.005). Both univariate and multivariate analyses showed that a high baseline sPD-L1 level was an independent factor associated with the PFS (hazard ratio [HR] 2.56, p = 0.011). Our study revealed that the sPD-L1 level was strongly related to the outcome of EGFR-TKIs in NSCLC patients harboring EGFR mutations.

Traditional Chinese Medicine Prolongs Progression-Free Survival and Enhances Therapeutic Effects in Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitor (EGFR-TKI)Treated Non-Small-Cell Lung Cancer (NSCLC) Patients Harboring EGFR Mutations.

BackgroundLung cancer is the most common cause of cancer-associated deaths worldwide. This study aimed to investigate the efficacy and safety of Traditional Chinese Medicine combining EGFR-TKIs in treatment of NSCLC patients harboring EGFR mutations.Material/MethodsThis study involved 153 advanced-stage NSCLC patients harboring EGFR mutations. Patients were divided into a Control group (administered EGFR-TKI, n=61) and an Experimental group (administered Traditional Chinese Medicine combining EGFR and TKI, n=92). Progression-free survival (PFS) was evaluated for exon 19 deletion and/or 21 deletion patients. Disease control rate (DCR) was assessed to observe therapeutic effects. Adverse effects, including rashes, diarrhea, ALT/AST increase, dental ulcers, and onychia lateralis, were also evaluated.ResultsTCM combining EGFR-TKI (90.11%) demonstrated no DCR improvement compared to single EGFR-TKI (83.33%) (p>0.05). Median PFS (mPFS) of TCM combining EGFR-TKI (13 months) was significantly longer compared to that in the single EGFR-TKI group (8.8 months) (p=0.001). For 19DEL mutant NSCLC, the mPFS (11 months) in TCM combining EGFR-TKI was significantly longer compared to single EGFR-TKI (8.5 months) (p=0.007). The mPFS of L858 mutant NSCLC patients in EGFR-TKI combining CTM (14 months) was significantly longer compared to single EGFR-TKI (9.5 months) (p=0.015). TCM combining EGFR-TKI was more inclined to prolong mPFS of NSCLC with exon 21 deletion. TCM combining EGFR-TKI illustrated no additional adverse effects in NSCLC patients (p=0.956).ConclusionsApplication of Traditional Chinese Medicine prolonged progression-free survival and enhanced therapeutic effect in NSCLC patients harboring EGFR mutations receiving EGFR-TKI treatment. Meanwhile, adjunctive Chinese medicine combining EGFR-TKI in NSCLC with EGFR mutations caused no adverse effects.

Leptomeningeal metastasis after effective first-generation EGFR TKI treatment of advanced non-small cell lung cancer

ObjectiveTo evaluate the influence of a first-generation epidermal growth factor receptor tyrosine kinase inhibitor (EGFR TKI) treatment on the clinical features of leptomeningeal metastasis (LM) progression and outcome in advanced non-small cell lung cancer (NSCLC) patients. MethodsWe retrospectively evaluated advanced NSCLC patients receiving effective first-generation EGFR TKI treatment (e.g., treatment > 6 months) at our institution between January 2008 and February 2014. Incidence, time to progression, and treatment outcome of LM were examined. ResultsIn our cohort, 29/420 patients (6.9%) developed LM. Among the patients harboring L858R or deletion of exon 19 in EGFR, the incidence of LM was 10.7% (21/197) and 3.4% (7/203), respectively (P = 0.006). The median time to LM progression was 16.5 months (95% confidence interval (CI), 11.9–20.8). The median overall survival (OS) after LM diagnosis was 5.2 months (95% CI, 3.2–7.2). In a subgroup analysis, OS was improved in patients with performance status (PS) ≤ 2 vs. PS > 2 (14.2 months vs. 2.3 months, respectively; P < 0.001). OS was also improved among patients who received, rather than did not receive, anti-tumor treatment (6.0 months vs. 1.9 months, respectively; P < 0.001) or whole brain radiotherapy (WBRT) (6.0 months vs. 3.9 months, respectively; P = 0.038). Multivariate analysis indicated that WBRT is a good prognostic factor (P = 0.048), whereas best support care (P = 0.033) and PS > 2 (P = 0.034) were poor prognostic factors. ConclusionA greater incidence of LM was observed in NSCLC patients harboring EGFR mutations after effective EGFR TKI treatment. In particular, the primary mutation, L858R, potentially predicts a higher risk of LM compared with deletion of exon 19. These results highlight the importance of determining mutation status when evaluating the biological behavior of LM in NSCLC patients who positively respond to EGFR TKI treatment.

Decreased human antigen�R expression confers resistance to�tyrosine kinase inhibitors in epidermal growth factor receptor-mutant lung cancer by inhibiting Bim expression

Primary resistance to epidermal growth factor receptor‑tyrosine kinase inhibitors (EGFR‑TKIs) is an obstacle for the treatment of non‑small cell lung cancer (NSCLC); however, the associated mechanisms are not well understood. Studies have reported that Bim expression levels may be associated with the efficacy of EGFR‑TKI treatment in NSCLC patients harboring EGFR mutations. Human antigenR (HuR) regulates the mRNA and protein expression of target genes, including certain B‑cell lymphoma2 family members. The present study investigated whether HuR mediates resistance to EGFR‑TKIs via the regulation of Bim. The results demonstrated that decreased levels of HuR and Bim protein expression are associated with primary resistance to EGFR‑TKIs and reduced median progression‑free survival in NSCLC patients. Invitro assays also revealed that knockdown of HuR resulted in primary EGFR‑TKI resistance and reduced gefitinib‑induced apoptosis in HCC827 cells by decreasing Bim expression. Furthermore, elevated HuR expression restored gefitinib sensitivity and enhanced gefitinib‑induced apoptosis in H1650 cells by increasing Bim expression. Invivo, it was further demonstrated that overexpression of HuR was able to restore the gefitinib sensitivity of H1650 cells. Therefore, altered HuR/Bim expression is proposed to be a novel mechanism of EGFR‑TKI resistance in NSCLC.

Abstract 5380: Whole-exome sequencing of Brazilian non-small cell lung cancer

Abstract Background: Non-Small Cell Lung Cancer (NSCLC) is the most common type of lung cancer with low survival rates. NSCLC patients harboring EGFR mutations are benefited by targeted therapy with tyrosine kinase inhibitors. The mutational profiling and the knowledge about recurrent mutations in Brazilian NSCLC is limited. Therefore, the detection of the mutation landscape of Brazilian NSCLC tumors is crucial for tailored therapy. Aim: To evaluate the mutational profiling of NSCLC of a Brazilian series. Methods: We analyzed a series of 40 NSCLC patients from Barretos Cancer Hospital. Clinical staging and exposure data were collected from all patients. Exome sequencing was performed in paired tumor/blood tissue DNA using the Illumina HiSeq2500™ System. Germline variations were excluded and the Genome Analysis Toolkit and VarScan were used for variants annotation and mutation detection. Results: Overall, 29 (72.5%) of cases were adenocarcinomas and 11 (27.5%) were squamous cell carcinoma (SCC) and the series was enriched by initial stages cases (I, n=16; II, n=12; III, n=6; IV, n=6). Regarding tobacco exposure, 33 patients were current smokers or former smokers and 7 patients were never smokers. In accordance, most of the cases presented the mutation signature 4, related to tobacco exposure, which is characterized by C&amp;gt;A substitutions and signature 29, related to tobacco chewing habit, which is characterized by C&amp;gt;A and C&amp;gt;T substitutions. All SCC patients were current or former smokers. TP53 gene was the most recurrently mutated gene observed in 48% (n=14) of the adenocarcinomas and 100% (n=11) of SCC cases (p=0,003). In adenocarcinomas, besides of TP53 gene, recurrent mutations were also found in KRAS (28%; n=8), STK11(21%; n=6), USP36 and APOB (14%; n=4/each), POLQ and CHD5 (10% n=3/each), EGFR and ANO3 (7%; n=2/each) and PDGFRA, BRAF, ERBB2, ERBB4, NRAS, RB1, CD22, CTNNA2 and ATR mutations were identified in only one adenocarcinoma case (3%). In SCC, besides of TP53 gene, recurrent mutations were also found in RB1, CD22, CTNNA2 and CHD7 (27%; n=3/each), ATR and APOB (18%; n=2/each), KRAS, PDGFRA, ERBB2, ERBB4, POLQ, CHD5 and ANO3 were identified in only one SCC case (9%). EGFR, STK11, BRAF, NRAS and USP36 mutations were exclusively found in adenocarcinomas and CHD7 mutations were exclusively found in SCC. Conclusions: The mutational landscape of lung adenocarcinoma and SCC are clearly different. A noteworthy number of pathogenic mutations was identified in this initial stages-enriched series. Our results may contribute to improve the knowledge about the molecular pathogenesis of NSCLC to better guide the clinical management with targeted therapies. Citation Format: Leticia Ferro Leal, Adriane Feijo Evangelista, Pedro R. de Marchi, Ysadhora Christiane Camargo Rodrigues, Eduardo Caetano Albino da Silva, Rui Manuel Reis. Whole-exome sequencing of Brazilian non-small cell lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5380.

Changes in programmed death ligand 1 expression in non-small cell lung cancer patients who received anticancer treatments.

The expression of programmed death ligand 1 (PD-L1) is considered a predictive biomarker of anti-programmed death 1 (PD-1)/PD-L1 cancer therapies. However, changes in PD-L1 expression of tumor cells during clinical courses have not been fully evaluated. We evaluated changes in PD-L1 expression for non-small cell lung cancer (NSCLC) patients who received anticancer treatments during clinical courses. In 76 NSCLC patients, PD-L1 expression was evaluated before and after anticancer treatment by immunohistochemical (IHC) analysis using an anti-PD-L1 antibody. We defined two cut-off points of PD-L1 expression (1 and 50%) and three corresponding IHC groups (A: 0%, B: 1-49%, and C: ≥50%). IHC group B and C were considered to be positive expression, and we defined the difference of IHC group between pre- and post-treatment as 'major change' in PD-L1 expression. Before anticancer treatment, PD-L1 expression was observed in 38/76 (50%) patients, and was significantly less common in patients harboring mutations in the epidermal growth factor receptor gene (EGFR) than in those without (P = 0.039). After anticancer treatment, PD-L1 expression was observed in 36/76 (47%) patients. Major increases in PD-L1 expression were seen in 11 (14%), and major decreases in 18 (24%) patients. Among 13 patients harboring EGFR mutations treated with EGFR tyrosine-kinase inhibitor (EGFR-TKI), five (38%) showed major increases. Major changes of PD-L1 expression in tumor cells were observed in 38% of NSCLC patients who received anticancer treatments. And, treatments with EGFR-TKI may increase PD-L1 expression in NSCLC patients harboring EGFR mutations.

Clinical efficacy of icotinib in lung cancer patients with differentEGFRmutation status: a meta-analysis

Icotinib is a novel and the third listed epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs), which exerts a good anti-tumor efficacy on non-small cell lung cancer (NSCLC). The efficacy of EGFR-TKIs has been shown to be associated with the EGFR mutation status, especially exon 19 deletion (19Del) and exon 21 L858R mutation. Therefore, a meta-analysis was performed to assess the efficacy of icotinib in NSCLC patients harboring EGFR mutations (19Del or L858R) and wild type (19Del and L858R loci wild type). A total of 24 studies were included for comparing the objective response rate (ORR) in the EGFR wild type and mutant patients treated with icotinib. The ORRs of EGFR mutant patients (19Del or L858R) are better than those of EGFR wild type patients (OR = 7.03(5.09–9.71), P < 0.00001). The pooling ORs from 21 studies on the disease control rate (DCR) in EGFR mutant patients are better than those of EGFR wild type patients (OR = 10.54(5.72–19.43), P < 0.00001). Moreover, the ORRs of EGFR 19Del patients are better than those of EGFR L858R patients after pooling ORs of 12 studies (OR = 2.04(1.12–3.73), P = 0.019). However, there was no significant difference on DCRs of EGFR 19Del patients and those of EGFR L858R patients (OR = 2.01(0.94–4.32), P = 0.072). Our findings indicated that compared with EGFR wild type patients, EGFR mutant patients have better ORRs and DCRs after icotinib treatment; EGFR 19Del patients treated with icotinib have better ORRs than EGFR L858R patients. EGFR mutation status is a useful biomarker for the evaluation of icotinib efficacy in NSCLC patients.

P3.02b-063 Analysis of Survival in EGFR-Mutation-Positive Advanced Non-Small-Cell Lung Cancer Patients with Miliary Pulmonary Metastasis: Topic: EGFR Clinical

Miliary pulmonary metastasis of non-small-cell lung cancer (NSCLC) indicates hematogenous dissemination and is more frequent in patients harboring EGFR mutations, and dramatic responses are often observed after treatment with EGFR-tyrosine kinase inhibitors (TKI). The relevance between miliary pulmonary metastasis and EGFR mutation has been suggested; therefore, we analyzed the survival in patients with miliary pulmonary metastasis harboring EGFR mutations treated with EGFR-TKI. We retrospectively analyzed 269 patients diagnosed with advanced or recurrent NSCLC treated with EGFR-TKI between 2005 and 2015 identified from the electronic database at our hospital. OS and PFS were estimated using the Kaplan–Meier method. We analyzed the survival in all eligible patients and performed propensity score matching based on clinical characteristics. A total of 215 NSCLC patients harboring EGFR mutations and treated with EGFR-TKIs were included in the study. Patients had a median age of 61 years (38–88 years). With regard to EGFR-TKIs, gefitinib was administered in 167 patients (77.7%), erlotinib in 30 (14.0%), and afatinib in 1 (0.5%). PFS for EGFR-TKI was 12.5 months [95% confidence interval (CI) 9.6–13.8 months) and OS was 23.7 months (95% CI: 20.3–27.2). A total of 31 patients with miliary pulmonary metastasis were identified; propensity matching identified 29 patients from each group with similar clinical characteristics. PFS between miliary pulmonary metastasis and matched control groups was 8.2 months (95% CI, 5.2–5.0) vs. 14.3 months (95% CI, 9.6–30.0) (p = 0.02), and OS was 15.3 months (95% CI, 11.0–20.3 months) vs. 27.9 months (95% CI, 22.0–33.0 months) (p = 0.003). The response rates did not show any significant difference between the two groups. The prognosis of patients with advanced NSCLC harboring EGFR mutations with miliary pulmonary metastasis demonstrated significantly worse outcome compared with those without miliary pulmonary metastasis.

Serum CYFRA21-1 is Correlated with the Efficacy of Epidermal Growth Factor Receptor-tyrosine Kinase Inhibitor in Non-small Cell Lung Cancer Patients Harboring EGFR Mutations

背景与目的表皮生长因子受体-酪氨酸激酶抑制剂(epidermal growth factor receptor-tyrosine kinase inhibitors, EGFR-TKIs)是EGFR基因突变晚期非小细胞癌(non-small cell lung cancer, NSCLC)患者一线标准治疗方案, 但是临床实践中, 疗效差异较大。本项实验拟研究治疗前血清细胞角蛋白19片段(cytokeratin-19 fragments, CYFRA21-1)和癌胚抗原(carcinoembryonic antigen, CEA)的水平是否与EGFR-TKIs疗效有关。方法回顾性分析194例EGFR基因突变阳性且接受EGFR-TKIs治疗的NSCLC患者的治疗前的血清CYFRA21-1和CEA水平与EGFR-TKIs疗效及生存时间的关系。结果血清水平CYFRA21-1增高和正常的无进展生存时间(progression-free survival, PFS)分别为7.0个月和11.9个月(P < 0.001);总生存(overall survival, OS)分别为12.6个月和28.0个月(P < 0.001)。腺癌中, 血清水平增高和正常的PFS分别为7.0个月和12.0个月(P < 0.001), OS分别为13.1个月和28.1个月(P < 0.001)。鳞癌中, 血清CYFRA21-1水平高低与生存时间无关。治疗前血清CEA水平高低与生存时间无关。结论在EGFR突变肺腺癌患者, 治疗前血清水平CYFRA21-1增高组EGFR-TKIs治疗的PFS和OS均较正常组短。EGFR突变肺腺癌患者, 治疗前血清CYFRA21-1水平可以作为预测EGFR-TKIs治疗的疗效指标。

Follow up analysis by exosomal miRNAs in EGFR mutated non-small cell lung cancer (NSCLC) patients during osimertinib (AZD9291) treatment: A potential prognostic biomarker tool.

e23035Background: NSCLC patients harboring EGFR mutations are able to receive approved tyrosine kinase inhibitors (TKIs) but to better assess the treatment responses new tools are needed. Liquid bi...

Gli1-Mediated Regulation of Sox2 Facilitates Self-Renewal of Stem-Like Cells and Confers Resistance to EGFR Inhibitors in Non–Small Cell Lung Cancer

Non–small cell lung cancer (NSCLC) patients have very low survival rates because the current therapeutic strategies are not fully effective. Although EGFR tyrosine kinase inhibitors are effective for NSCLC patients harboring EGFR mutations, patients invariably develop resistance to these agents. Alterations in multiple signaling cascades have been associated with the development of resistance to EGFR inhibitors. Sonic Hedgehog and associated Gli transcription factors play a major role in embryonic development and have recently been found to be reactivated in NSCLC, and elevated Gli1 levels correlate with poor prognosis. The Hedgehog pathway has been implicated in the functions of cancer stem cells, although the underlying molecular mechanisms are not clear. In this context, we demonstrate that Gli1 is a strong regulator of embryonic stem cell transcription factor Sox2. Depletion of Gli1 or inhibition of the Hedgehog signaling significantly abrogated the self-renewal of stem-like side-population cells from NSCLCs as well as vascular mimicry of such cells. Gli1 was found to transcriptionally regulate Sox2 through its promoter region, and Gli1 could be detected on the Sox2 promoter. Inhibition of Hedgehog signaling appeared to work cooperatively with EGFR inhibitors in markedly reducing the viability of NSCLC cells as well as the self-renewal of stem-like cells. Thus, our study demonstrates a cooperative functioning of the EGFR signaling and Hedgehog pathways in governing the stem-like functions of NSCLC cancer stem cells and presents a novel therapeutic strategy to combat NSCLC harboring EGFR mutations.

Update on third-generation EGFR tyrosine kinase inhibitors.

Among patients with non-small cell lung cancer (NSCLC), EGFR mutations, 90% of which present as an exon 19 deletion or exon 21 point mutation L858R, have been detected in Western and Asian populations at a rate of ~15% and ~40%, respectively. To date, numerous trials have established the efficacy and toxicity profile of singleagent oral EGFR-tyrosine kinase inhibitor (TKI) therapies for EGFR-TKI-naive NSCLC patients harboring EGFR mutations. These trials include IPASS for gefitinib (1), Optimal for erlotinib (2), and LUX-Lung 3 for afatinib (3). Still, the majority of patients will eventually develop resistance.

Value of carcinoembryonic antigen levels in predicting the efficacy of EGFR-TKI in advanced non-small cell lung cancer harboring EGFR mutations

To explore the relevance of carcinoembryonic antigen (CEA) level and efficacy of epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) in advanced non-small cell lung cancer (NSCLC) harboring EGFR mutations. Between September 2010 and December 2013, 170 NSCLC patients harboring EGFR mutations receiving EGFR-TKI treatment at pulmonary medicine department of Shanghai Chest hospital were retrospectively screened. They were screened for clinical characteristics, efficacy of EGFR-TKI, and tumor markers (CEA/cytokerantin-19-fragment CYFRA21-1) at an initial diagnosis. The cutoff value for CEA was 5 µg/L. The overall objective response rate (ORR) was 37.6% and disease control rate (DCR) 90.0%. Those with high CEA levels (>5 µg/L) had better DCR (94.3% vs 80.4%, P = 0.022). Univariate analysis showed that patients with high CEA levels ( ≥ 20 µg/L) had significantly longer progression-free survival (PFS) than those with low CEA level (HR = 1.444, 95%CI: 1.036-2.014, P = 0.030). HR value increased with rising CEA levels. No significant difference in PFS existed between high-CYFRA21-1 and normal-CYFRA21-1 groups (HR = 1.167, 95%CI: 0.840-1.622, P = 0.357). Close follow-ups were conducted for 51 patients on EGFR-TKI treatment. And their CEA levels was tested within one month after treatment. The patients in descending type group had longer PFS than other two types (HR = 7.344, 95%CI: 2.903-18.578, P < 0.001). CEA level has a close correlation with the efficacy of EGFR-TKI treatment. And a high CEA level may be a predictive marker for better response and longer PFS in advanced NSCLC.

Cytokeratin 19 Fragment Predicts the Efficacy of Epidermal Growth Factor Receptor–Tyrosine Kinase Inhibitor in Non–Small-Cell Lung Cancer Harboring EGFR Mutation

EGFR gene mutation is independently associated with a favorable response in non-small-cell lung cancer (NSCLC) patients receiving epidermal growth factor receptor -tyrosine kinase inhibitors (EGFR-TKIs), regardless of sex or smoking history. Squamous cell carcinoma patients harboring EGFR mutations show a significantly worse response to EGFR-TKIs compared with adenocarcinoma patients. We hypothesized that the serum cytokeratin 19 fragment (CYFRA 21-1) is associated with the efficacy of EGFR-TKIs in EGFR-mutated NSCLC patients. We retrospectively screened 160 NSCLC patients harboring EGFR mutations, who had received either gefitinib, or erlotinib between 1992 and 2011. Patients were screened for clinical characteristics, the efficacy of EGFR-TKI, and tumor markers (carcinoembryonic antigen [CEA]/CYFRA 21-1) at the initial diagnosis. Of 160 eligible patients treated with EGFR-TKIs, 77 patients with high CYFRA 21-1 level (>2 ng/ml) showed significantly shorter progression-free survival (PFS) than the 83 patients with normal CYFRA 21-1 level (median PFS, 7.5 versus 13.3 months; p < 0.001). No significant difference in PFS was observed between the high-CEA group (>5 ng/ml) and the normal-CEA group (median PFS, 8.6 versus 11.2 months; p = 0.242). A multivariate analysis revealed that high CYFRA 21-1 level is independently associated with PFS (hazard ratio, 1.27; p = 0.002). No significant difference in overall survival was observed between the high- and the normal-CYFRA 21-1 groups (median overall survival, 24.8 versus 39.1 months; p = 0.104). Patients with a high CYFRA 21-1 level have significantly shorter PFS. CYFRA 21-1 is not a prognostic but a predictive marker of EGFR-TKI treatment in EGFR-mutated NSCLC patients.

P1-056 - Cytokeratin 19 Fragment (CYFRA21-1) Predicts the Efficacy of the Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitor (EGFR-TKI) in Non-Small-Cell Lung Cancer (NSCLC) Harboring EGFR Mutation

ABSTRACT Background EGFR mutation is independently associated with a favorable response in NSCLC patients receiving EGFR-TKIs, regardless of gender or smoking history. However, recent reports have indicated that squamous cell carcinoma patients harboring EGFR mutations show a worse response to EGFR-TKIs than adenocarcinoma patients. We hypothesized that serum CYFRA21-1 is a predictive marker in EGFR-mutated patients treated with EGFR-TKIs. Methods We retrospectively screened 160 NSCLC patients harboring EGFR mutations (exon 19 deletions, L858R in exon 21, or other minor mutations) who received either gefitinib or erlotinib between 1992 and 2011. Patients were screened for histology, sex, age, smoking status, efficacy of EGFR-TKI and tumor markers (CEA/CYFRA21-1) at initial diagnosis. Results Out of 160 eligible patients treated with EGFR-TKIs, 77 patients with a high CYFRA21-1 level (>2 ng/ml) showed statistically shorter progression-free survival (PFS) than 83 patients with a normal CYFRA21-1 level (median PFS 7.5 versus 14.0 months, P = 0.006). No significant difference in PFS was observed between the high CEA group (>5 ng/ml) and the normal CEA group (median PFS 8.6 versus 11.2 months, P = 0.2423). Multivariate analysis revealed that a high CYFRA21-1 level is independently associated with PFS (HR 1.35; P = 0.002) as well as squamous cell carcinoma (HR 1.40; P = 0.020) and performance status 2–4 (HR 2.63; P = 0.003). No statistically significant difference in overall survival (OS) was observed between the high CYFRA21-1 group and the normal group (median OS 24.8 versus 39.1 months, P = 0.104). Conclusions High CYFRA level patients have significantly shorter PFS, which may indicate that this subgroup has a larger squamous component and thus less response to EGFR-TKIs. The serum CYFRA21-1 level is a predictive marker of EGFR-TKIs efficacy and EGFR-mutated patients can be divided into two subgroups according to the CYFRA21-1 level at initial diagnosis.