Proximal Femoral Metastasis From Epidermal Growth Factor Receptor-Mutated Lung Adenocarcinoma Mimicking Osteosarcoma on Magnetic Resonance Imaging.

The aggressive nature of lung cancer is frequently accompanied by a high incidence of bone metastasis; however, proximal femoral metastasis from lung cancer is comparatively uncommon when compared to other malignancies. In this report, we present the case of a 53-year-old Asian male who presented with pain in the left thigh and back. Magnetic resonance imaging revealed severe bone destruction with involvement of adjacent soft tissue mass at the left thigh, exhibiting imaging findings that mimic osteosarcoma. Subsequent bone biopsy confirmed the diagnosis of epidermal growth factor receptor (EGFR)-mutated lung adenocarcinoma with bone metastasis. The patient achieved survival following administration of osimertinib and underwent surgery for femoral metastases without palliative surgery for lung cancer. Therefore, proximal femoral metastasis from EGFR-mutated lung adenocarcinoma should be considered as a differential diagnosis in patients suspected to have osteosarcoma. The imaging findings of proximal femoral metastasis from EGFR-mutated lung adenocarcinoma were presented, and their therapeutic management was discussed.

Analysis of tumor abnormal protein expression and epidermal growth factor receptor mutation status in non-small cell lung cancer.

BACKGROUND: The level of tumor abnormal protein (TAP) level has a significant impact on tumor growth, recurrence, and metastasis. Previous studies have highlighted the influence of the mutations in exons 19 and 21 of the epidermal growth factor receptor (EGFR), particularly the sensitivity displayed by tumor cells to epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) therapy. Our study is centered on exploring the clinical relevance of TAP and EGFR mutations in patients with non-small cell lung cancer (NSCLC). MATERIAL AND METHODS: In this study, tissue samples were collected from a total of 176 patients diagnosed with non-small cell lung cancer (NSCLC). Real-time PCR technology was utilized to detect mutations within exons 19 and 21 of the epidermal growth factor receptor (EGFR) gene in these samples. This approach enables precise identification of EGFR mutations associated with NSCLC. Furthermore, the study investigated the impact of various tumor markers, including tumor abnormal protein (TAP) and carcinoembryonic antigen (CEA), on EGFR mutation status. Established assays were employed to evaluate TAP and CEA levels, aiming to ascertain their potential correlation with EGFR mutation in NSCLC patients. RESULTS: EGFR exhibited mutation rates of 23.86% and 12.50% in exons 19 and 21, respectively. EGFR mutations were more prevalent in younger women (< 60 years old) and in cases with pleural invasion, vessel invasion, CEA > 6.5 ng/mL, and TAP > 228 µm2 for both genders. Increased TAP levels independently predicted EGFR mutations (P = 0.001 for males; P = 0.000 for females). An area under the curve (AUC) of 0.833 indecated EGFR mutation prediction with sensitivity and specificity of 79.7% and 87.0%, respectively. For females, the sensitivity increased to 89.7% and specificity increased to 93.8%. CONCLUSIONS: TAP effectively predicts EGFR mutations in NSCLC patients with moderate accuracy, particularly benefiting diagnosis in females with high sensitivity and specificity. Integrating TAP assessment into EGFR mutation testing can significantly enhance diagnostic precision, especially in female NSCLC cases.

A Visual Analysis of the Research Dynamics in Resistance to EGFR Inhibitors for NSCLC.

Purpose: Activating mutations in epidermal growth factor receptor (EGFR) have been identified as key predictive biomarkers for the customized treatment with EGFR tyrosine kinase inhibitors (TKIs) in non-small cell lung cancer (NSCLC), aiding in improving patient response rates and survival. However, resistance challenges the efficacy of these treatments, with limited understanding of post-resistance therapeutic strategies. A deep understanding of the biology and resistance mechanisms of EGFR-mutant NSCLC is crucial for developing new treatment approaches. This study, through bibliometric analysis, summarizes the trends in research on resistance to EGFR-TKIs. Methods: Research papers on NSCLC with EGFR inhibitor resistance were collected from the Web of Science Core Collection (WoSCC). The analysis utilized bibliometric tools like CiteSpace, VOSviewer, and other platforms for comprehensive analysis and visualization of the outcomes. Results: The WoSCC database contains a total of 5866 documents on resistance to EGFR-TKIs treatment, including 4727 articles (93.48%) and 1139 reviews (6.52%), spanning 81 countries and regions, 4792 institutions, with the involvement of 23,594 authors. Since 2016, there has been a significant increase in publications in this field. China has the highest publication output, while the United States has the highest citation count for papers. Harvard University leads in terms of the number of publications. Among the top ten journals with the highest output, Clinical Cancer Research has the highest impact factor at 11.5, with 90% of the journals classified in Q1 or Q2. Rafael Rosell is one of the most influential authors in this field, ranking second in publication volume and fourth in citation count. Research on EGFR-TKIs resistance mainly focuses on genetic testing, resistance mechanisms, and post-resistance treatment strategies. Conclusion: This study provides researchers with a reliable basis and guidance for finding authoritative references, understanding research trends, and exploring potential directions.

Therapeutic Resistance in G-CSF Producing Lung Cancer With EGFR Mutation.

Background/Aim: Granulocyte colony-stimulating factor (G-CSF)-producing neoplasms are relatively rare; however, little is known on the clinical features of G-CSF-producing lung cancer harboring activating epidermal growth factor receptor (EGFR) mutations. Case Report: A 66-year-old female was definitively diagnosed with G-CSF-producing lung cancer that was positive for EGFR mutations. She repeatedly received epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs), such as osimertinib and afatinib. However, she developed resistance to these molecular-targeting drugs within 2 to 3 months after immediate shrinkage. Thus, the patient was treated with chemoimmunotherapy including bevacizumab, and demonstrated a slight survival benefit. Conclusion: Overall, G-CSF-producing lung cancers positive for EGFR mutations were resistant to different treatment modalities. Clinicians should be attentive to the potential resistance of G-CSF-producing EGFR mutant lung cancer to EGFR-TKI therapy.

Durable Response of Pembrolizmab for EGFR Mutation-positive Lung Adenocarcinoma with Early Progression to Osimertinib in First-line Treatment.

Osimertinib, a third-generation epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI), is the standard first-line treatment for EGFR mutation-positive non-small-cell lung cancer (NSCLC) and demonstrates favorable disease control. Conversely, immune checkpoint inhibitors (ICIs) that target programmed cell death-1/programmed cell death ligands demonstrate a restrictive tumor response. We herein report a patient who achieved a durable response to pembrolizumab following early progression within two months of osimertinib administration for EGFR mutation-positive lung adenocarcinoma. Our findings suggest that treatment with ICIs for patients with EGFR mutation-positive NSCLC experiencing early progression to osimertinib as first-line treatment might represent a viable approach.

Patients' Preferences for Adjuvant Osimertinib in Non-Small-Cell Lung Cancer After Complete Surgical Resection: What Makes It Worth It to Patients?

BACKGROUND: The ADAURA trial confirmed adjuvant Osimertinib's efficacy in EGFR-mutated Non-small-cell lung cancer (NSCLC), yet the limited mature overall survival (OS) data at approval poses a challenge. This study explores patient preferences in the absence of complete OS information, hypothesizing that disease-free survival (DFS) benefit alone may influence adjuvant Osimertinib pursuit. METHODS: At Roswell Park Comprehensive Cancer Center (Jan-Dec 2021), patients assessed for adjuvant therapy received a survey probing OS and DFS preferences. Scenarios were (a) minimum OS justifying Osimertinib, (b) minimum DFS improvement justifying 3-years of adjuvant Osimertinib, (c) minimum 5-year DFS percent change, and (d) minimum OS justifying copay changes. Results were analyzed. RESULTS: Of 524 NSCLC patients, 51 participated. Scenario 1 saw 56% requiring a 12-month OS benefit for Osimertinib justification. In scenario 2, 72% deemed a 12-month DFS benefit sufficient. Scenario 3 revealed 31% opting out despite a 10% OS increase. Scenario 4 showed varied willingness to pay, with 33% unwilling to any shoulder copayment even with a 10-year OS benefit. CONCLUSION: This study explores patient preferences without complete OS data, revealing diverse thresholds. Factors include employment, education, and willingness to pay. Findings underscore shared decision-making importance. Limitations include sample size, potential biases, and regional focus; larger cohorts are needed for validation.

Prognostic value of the international association for the study of lung cancer grading system and its association with the tumor microenvironment in stage I EGFR-muted lung adenocarcinoma.

INTRODUCTION: The International Association for the Study of Lung Cancer (IASLC) grading system predicts early lung adenocarcinoma outcomes. METHODS: The purpose of this study is to examine prognostic value of the IASLC grading system and its association with the tumor microenvironment (TME) in Stage I EGFR-muted lung adenocarcinoma. Based on the IASLC grading system, we compared the clinicopathological characteristics of EGFR-mutated lung adenocarcinoma (n = 296). In addition, we examined the expression level of E-cadherin in tumor cells and counted the number of tumor-infiltrating lymphocytes (TILs; CD8, CD20, CD138, and Foxp3), tumor-associated macrophages (TAMs; CD204), and cancer-associated fibroblasts (CAFs; podoplanin) using semi-automatic digital pathology image analysis. RESULTS: Recurrence-free survival (RFS) curve showed that survival of grade 3 was significantly shorter than that of grade 1 (P < 0.01) and grade 2 (P = 0.03). Multivariate analysis of RFS revealed the invasive size, lymphatic permeation, and grade 3 (P < 0.01) as independent poor prognostic factors. The number of CD204 +TAMs and PDPN+CAFs was significantly higher in grade 3 than in grade 1 or 2 (all P < 0.01). Among the intermediate grade by the predominant subtype based classification, cases classified as grade 3 by the new classification had higher number of CD204 +TAMs (P < 0.01) and PDPN+CAFs (P = 0.02) than those classified as grade 2. CONCLUSION: The IASLC grading system correlated with the outcomes of EGFR-mutated lung adenocarcinoma. Grade 3 was found to have the TME that most contributes to tumor progression, which probably explained their poor prognosis.

Combined Dacomitinib and Selpercatinib Treatment for a Patient with EGFR-Mutant Non-Small Cell Lung Cancer and Acquired CCDC6-RET Fusion.

RET rearrangements are recognized drivers in lung cancer, representing a small subset (1-2%) of non-small cell lung cancer (NSCLC). Additionally, RET fusions also serve as a rare acquired resistance mechanism in EGFR-mutant NSCLC. Only a few NSCLC cases have been reported with co-occurrence of EGFR mutations and RET fusions as an acquired resistance mechanism induced by EGFR-tyrosine kinase inhibitors (TKIs). A 68-year-old man diagnosed with lung adenocarcinoma harboring EGFR L858R mutation initially responded well to dacomitinib, a second-generation EGFR-tyrosine kinase inhibitor (TKI). Afterward, he developed acquired resistance accompanied by a RET rearrangement. Next-generation sequencing (NGS) analysis revealed that the tumor possessed both the new CCDC6-RET fusion and the EGFR L858R mutation. Subsequently, he was treated with a combination of cisplatin, pemetrexed, and bevacizumab resulting in a partial response. Nevertheless, his condition deteriorated as the disease progressed, manifesting as hydrocephalus, accompanied by altered consciousness and lower limb weakness. The subsequent combined treatment with dacomitinib and selpercatinib resulted in a significant improvement in neurological symptoms. Here, we first identified acquired CCDC6-RET fusion with a coexisting EGFR L858R mutation following dacomitinib treatment. Our findings highlight the importance of NGS for identifying RET fusions and suggest the potential combination of dacomitinib and selpercatinib to overcome this resistance. For NSCLC patients with RET rearrangements and no access to RET inhibitors, pemetrexed-based chemotherapy provides a feasible alternative.

EGFR mutation testing, treatment and survival in stage I-III non-small-cell lung cancer: CancerLinQ Discovery database retrospective analysis.

Aim: To describe real-world biomarker testing, treatment and survival in stage IA-IIIC non-small-cell lung cancer (NSCLC). Methods: Electronic records of USA-based patients in the CancerLinQ Discovery® database with stage IA-IIIC NSCLC (diagnosed between 2014 and 2018) were screened; a curated cohort of 14,452 records was identified for further analysis. Results: Of 3121 (21.6%) patients who had EGFR testing, 493 (15.8%) were EGFR-mutation positive. Of 974 patients who underwent surgical resection, 513 (52.7%) received adjuvant therapy. A quarter of patients with EGFR-mutation positive NSCLC received targeted adjuvant therapy. Conclusion: Approximately a fifth of patients underwent EGFR testing; biomarker testing is important to ensure optimal outcomes for patients with stage I-III NSCLC.

A study investigating how many patients with early-stage non-small-cell lung cancer (NSCLC) had mutations in a protein called EGFR and which treatments they received in routine clinical practice: The treatment recommended by medical experts for stage IA­IIIA non-small-cell lung cancer (NSCLC) is surgical removal of the growth (tumor). Patients with stage II or III, and some with stage IB disease, are recommended to receive treatment with medications such as chemotherapy or oral cancer treatments after surgery (adjuvant treatment). In some lung cancers, there are mutations in a protein called EGFR. Osimertinib, a drug that blocks the activity of mutated EGFR on cancer cells, reducing their growth and spread, is recommended as an adjuvant treatment for patients with EGFR-mutated, stage IB­IIIA NSCLC. This study aimed to understand how many patients with stage I­III NSCLC have tumors with EGFR mutations, and which treatments patients received in everyday clinical practice, before new medicines such as osimertinib (that treat EGFR-mutated NSCLC) were recommended. We looked at anonymous data from 14,452 patients with stage I­III NSCLC treated at cancer clinics in the USA between 2014 and 2018. We found that 3121 (21.6%) patients had an EGFR mutation test and 493 (15.8%) had EGFR-mutation positive NSCLC. Of patients who had surgery to remove the tumor, 55% received adjuvant therapy (treatment after surgery). It is important to perform EGFR mutation testing in patients with stage IB­IIIA NSCLC so that patients with EGFR-mutation positive NSCLC can receive appropriate treatment.

Pathological findings of pulmonary papillary adenoma with EGFR mutation and literature review: two cases report.

OBJECTIVE: Pulmonary papillary adenoma is an extremely rare benign tumor. It is derived from type II lung cells and club cells, suggesting that it may originate from stem cells with two-way differentiation. Only one case has been reported with FGFR2-IIIb overexpression. METHODS: Two cases of pulmonary papillary adenoma with available data on clinical features, histological morphology, immunophenotype and molecular characteristics were analyzed. RESULTS: Both tumors were well-circumscribed unencapsulated nodules composed of papillary structures with fibrovascular cores lined by a single layer of cuboidal or columnar epithelium without necrosis, nuclear atypia and mitoses, or invasion. But malignant transformation features include complex branching structures and significantly enlarged, irregular, and crowded malignant cells in one case. Immunohistochemistry showed that the tumor cells were strongly positive for TTF1, NapsinA, EMA and CK7 and negative for CEA and P63, with a low Ki-67 proliferation index. The EGFR somatic mutation exon19:c.2236_2256delinsATC (p.E746_S752delinsI) was found in one case by next-generation sequencing (NGS) technology. CONCLUSION: Pulmonary papillary adenoma is very rare. Virtually all papillary adenomas are clinically silent and discovered incidentally. They are benign tumors, and resection is curative. An EGFR 19 exon deletion mutation in a patient with this tumor type was detected for the first time by NGS, and our results suggest that the malignant transformation of pulmonary papillary adenoma may be mediated by EGFR mutation.

Expansion of tumor-infiltrating lymphocytes in non-small cell lung cancer: Clinical potential and efficacy in EGFR mutation subsets.

Our study aimed to expand tumor-infiltrating lymphocytes (TILs) from primary non-small cell lung cancers (NSCLCs) and evaluate their reactivity against tumor cells. We expanded TILs from 103 primary NSCLCs using histopathological analysis, flow cytometry, IFN-γ release assays, cell-mediated cytotoxicity assays, and in vivo efficacy tests. TIL expansion was observed in all cases, regardless of EGFR mutation status. There was also an increase in the median CD4+/CD8+ ratio during expansion. In post-rapid expansion protocol (REP) TILs, 13 out of 16 cases, including all three cases with EGFR mutations, exhibited a two-fold or greater increase in IFN-γ secretion. The cytotoxicity assay revealed enhanced tumor cell death in three of the seven cases, two of which had EGFR mutations. In vivo functional testing in a patient-derived xenograft model showed a reduction in tumor volume. The anti-tumor activity of post-REP TILs underscores their potential as a therapeutic option for advanced NSCLC, irrespective of mutation status.

CD155 Expression in Early-stage Lung Adenocarcinoma.

BACKGROUND: CD155 is a transmembrane protein that belongs to the nectin-like molecule family that is widely overexpressed in several types of cancer. However, the clinical significance of CD155 in pathological stage I lung adenocarcinoma remains poorly understood. METHODS: We analyzed 320 patients diagnosed with pathological stage I lung adenocarcinoma who underwent surgical treatment at Kyushu University Hospital between 2006 and 2015. The number of tumor cells expressing CD155 was assessed by immunohistochemistry, and patients were categorized into high and low CD155 expression groups. We compared the clinicopathological characteristics and clinical outcomes between these groups. RESULTS: EGFR mutation status was determined in 237 patients. A total of 106 patients (33.1%) had EGFR wild-type, while 131 patients (40.9%) were EGFR mutant-type. Regarding CD155 expression, 77 patients (24.1%) were classified as high and 243 (75.9%) as low. The multivariate analysis identified pleural invasion and EGFR wild-type as independent predictors of high CD155 expression. The Kaplan-Meier plot demonstrated significantly poorer recurrence-free survival and overall survival in the high CD155 group compared with the low CD155 group. In multivariate analysis, high CD155 expression was an independent poor prognostic factor for both recurrence-free and overall survival. Subgroup analyses revealed that a prognostic difference related to CD155 expression was observed only in patients with EGFR wild-type but not in those with EGFR mutant-type. CONCLUSIONS: Our findings suggest that high expression of CD155 is associated with EGFR wild-type and could serve as a valuable prognostic marker in pathological stage I lung adenocarcinoma, particularly in cases without EGFR mutation.

Accurate Early Detection and EGFR Mutation Status Prediction of Lung Cancer Using Plasma cfDNA Coverage Patterns: A Proof-of-Concept Study.

Lung cancer is a major global health concern with a low survival rate, often due to late-stage diagnosis. Liquid biopsy offers a non-invasive approach to cancer detection and monitoring, utilizing various features of circulating cell-free DNA (cfDNA). In this study, we established two models based on cfDNA coverage patterns at the transcription start sites (TSSs) from 6X whole-genome sequencing: an Early Cancer Screening Model and an EGFR mutation status prediction model. The Early Cancer Screening Model showed encouraging prediction ability, especially for early-stage lung cancer. The EGFR mutation status prediction model exhibited high accuracy in distinguishing between EGFR-positive and wild-type cases. Additionally, cfDNA coverage patterns at TSSs also reflect gene expression patterns at the pathway level in lung cancer patients. These findings demonstrate the potential applications of cfDNA coverage patterns at TSSs in early cancer screening and in cancer subtyping.

Investigation of RBM10 mutation and its associations with clinical and molecular characteristics in EGFR-mutant and EGFR-wildtype lung adenocarcinoma.

Background: RBM10 is commonly mutated in lung adenocarcinoma (LUAD). However, its role in the pathogenesis of LUAD remains undefined. EGFR-mutant LUAD represents a distinct subset of non-small cell lung cancer (NSCLC). The function of RBM10 in tumor pathogenesis is supposed to differ between EGFR-mutant and EGFR-wt LUAD. This study aimed to interrogate the prevalence of RBM10 mutation in a large cohort of Chinese patients with LUAD and investigate the association of RBM10 mutation with clinical and molecular characteristics of EGFR-mutant and EGFR-wt LUAD. Methods: Tumor sequencing data from 2848 Chinese patients with LUAD were retrospectively reviewed and analyzed. The prevalence of RBM10 was also compared with other three cohorts: OrigMed (n = 1222), MSKCC (n = 1267), and TCGA (n = 566). The associations of RBM10 mutation with clinical and molecular characteristics were assessed. An external cohort of 182 patients with LUAD who received PD-1 inhibitor were used to investigate the association of RBM10 mutation with clinical outcomes upon immunotherapy. Results: Our cohort showed a higher prevalence of RBM10 in EGFR-mutant LUAD than in EGFR-wt LUAD (14.8 % vs. 6.5 %, p < 0.001). The enrichment of RBM10 mutations in EGFR-mutant LUAD was also seen in another Chinese cohort (OrigMed: 14.9 % vs. 7.8 %, p < 0.001), but not in the two western cohorts (MSKCC: 7.4 % vs. 9.5 %, p = 0.272; TCGA: 8.1 % vs. 6.7 %, p = 0.624). RBM10 mutations co-occurred more frequently with EGFR L858R mutations (23.7 %) than with other types of EGFR mutations (19 del: 7.7 %; other: 7.1 % in others, p < 0.001). In EGFR-mutant LUAD, RBM10 mutations were more commonly found in stage I (18.2 %) and II (21.8 %) vs. stage III (9.4 %) and IV (11.3 %) tumors (p < 0.001). The proportion of PD-L1 positive expression in EGFR-mutant LUAD with concomitant RBM10 mutation was not different from that those without RBM10 mutations (41.8 % vs. 47.9 %, p = 0.566). In contrast, RBM10 mutation occurred more frequently in EGFR-wt LUAD at stage II-IV (stage II: 12.0 %, stage III: 8.7 %, stage IV: 6.6 %) than at stage I (2.8 %). EGFR-wt LUAD with concomitant RBM10 mutations had higher proportions of PD-L1 expression positivity (78.9 % vs. 61.9 %, p = 0.014) and higher tumor mutational load (8.97 vs. 2.99 muts/Mb, p < 0.001) than those without. Patients with EGFR-wt LUAD who also harbored RBM10 loss of function (LOF) mutations had a longer median PFS upon immunotherapy than those with RBM10 non-LOF mutations (7.15 m vs. 2.60 m, HR = 4.83 [1.30-17.94], p = 0.010). Conclusion: We comprehensively investigated RBM10 mutations in a Chinese cohort with LUAD. Compared to western cohorts, a significant enrichment of RBM10 mutations in EGFR-mutant LUAD compared to EGFR-wildtype LUAD in the Chinese population. RBM10 mutation shows different associations with clinical and molecular characteristics between EGFR-mutant and EGFR-wt LUAD, suggesting a divergent mechanism between these two subsets via which RBM10 deficiency contribute to tumor pathogenesis. The findings contribute to our understanding of the molecular landscape of LUAD and highlight the importance of considering population-specific factors in cancer genomics research.

Effect of Epidermal Growth Factor Receptor Mutation on Positron Emission Tomography/Computed Tomography in Lung Cancer.

BACKGROUND/AIM: This study analyzed the effect of epidermal growth factor receptor (EGFR) mutations on fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (F-18 FDG PET/CT) results in lung cancer and the pathological findings in patients subjected to surgery. PATIENTS AND METHODS: A total of 210 patients diagnosed with lung cancer by F-18 FDG PET/CT at Inje University Busan Paik Hospital between January 2018 and December 2023 were recruited. EGFR mutation tests were performed on biopsy specimens. Overall, 78 patients (37.1%) with EGFR mutations were included in this study. Twenty-seven patients (12.9%) had distant metastases at the time of diagnosis. Of all patients, 69 (32.9%) underwent surgery at our hospital, and their pathological findings were analyzed. RESULTS: The maximum standardized uptake value (SUVmax) of F-18 FDG PET/CT was <10 in patients with EGFR mutations. Patients with EGFR mutations were not commonly diagnosed with diabetes. When analyzing the pathological findings after surgery in the 69 patients, adenocarcinoma was more common in those with EGFR mutations. In contrast, perineural invasion was more common in patients without EGFR mutations. When analyzing the results of 69 patients with postoperative pathology, 25 relapsed during the median follow-up of 21.7 months (range=0.9-58.4 months). Patients who underwent surgery and had EGFR mutations (n=26) exhibited lower recurrence rates compared to those without EGFR mutations. Disease-free survival was longer in patients with EGFR mutations. CONCLUSION: In non-small-cell lung cancer with an EGFR mutation, the F-18 FDG PET/CT SUVmax value and the probability of recurrence were lower. EGFR mutations are associated with low-glucose metabolism.

Real-world study of lazertinib as second-line or greater treatment in advanced non-small cell lung cancer.

BACKGROUND: Lazertinib is an oral, third-generation EGFR-TKI, which specifically targets the EGFR T790M mutation along with activating mutations Ex19del and L858R. More real-world data are needed to evaluate its efficacy and safety in treating locally advanced and metastatic non-small cell lung cancer (NSCLC) following prior EGFR TKI treatment. METHODS: This multicenter retrospective study was conducted at seven university hospitals affiliated to the Catholic Medical Center (CMC) in Korea. A clinical data warehouse (CDW) platform was used to access and extract information. RESULTS: A total of 48 patients were assessed. The majority were female (75%) and diagnosed with adenocarcinoma (95.8%). All patients had the EGFR mutation at diagnosis, 27 (56.3%) had the exon 19 deletion, 20 (41.7%) had the L858R mutation, and one (2.0%) had the exon 18 mutation. The median progression-free survival (PFS) was 15.4 months. At 6, 12, and 18 months, PFS rates were 79.1%, 53.6%, and 27.3%, respectively. When PFS was analyzed by prior TKI duration (<18 months vs. >18 months), significant differences were noted at the 6 and 9-month mark (p = 0.013 and p = 0.010, respectively). In multivariate analysis for PFS, only prior TKI duration and ECOG score showed statistical significance (p = 0.026 and p = 0.049, respectively). In the multivariate analysis for OS, ECOG score showed statistical significance (p = 0.006). Among 48 patients, 34 (70.8%) experienced adverse events (AEs) related to lazertinib. The most frequent AEs were skin reaction (29.8%), diarrhea (21.3%), and peripheral neuropathy (20.8%). CONCLUSIONS: The results suggest that lazertinib is effective in second or more line settings, with tolerable safety profile. More patient data are necessary to find possible prognostic markers associated with patient outcome.

Microfluidics-based EGFR mutation detection and its implication in the resource-limited clinical setting.

Management of lung cancer today obligates a mutational analysis of the epidermal growth factor receptor (EGFR) gene particularly when Tyrosine Kinase Inhibitor (TKI) therapy is being considered as part of prognostic stratification. This study evaluates the performance of automated microfluidics-based EGFR mutation detection and its significance in clinical diagnostic settings. Formalin-fixed, paraffin-embedded (FFPE) samples from NSCLC patients (n = 174) were included in a two-phase study. Phase I: Validation of the platform by comparing the results with conventional real-time PCR and next-generation sequencing (NGS) platform. Phase II: EGFR mutation detection on microfluidics-based platform as part of routine diagnostics workup. The microfluidics-based platform demonstrates 96.5% and 89.2% concordance with conventional real-time PCR and NGS, respectively. The system efficiently detects mutations across the EGFR gene with 88.23% sensitivity and 100% specificity. Out of 144 samples analysed in phase II, the platform generated valid results in 94% with mutation detected in 41% of samples. This microfluidics-based platform can detect as low as 5% mutant allele fractions from the FFPE samples. Therefore the microfluidics-based platform is a rapid, complete walkaway, with minimum tissue requirement (two sections of 5 µ thickness) and technical skill requirement. The method can detect clinically actionable EGFR mutations efficiently and can be considered a reliable diagnostic platform in resource-limited settings. From receiving samples to reporting the results this platform provides accurate data without much manual intervention. The study helped to devise an algorithm that emphasizes effective screening of the NSCLC cases for EGFR mutations with varying tumour content. Thus it helps in triaging the cases judiciously before proceeding with multigene testing.

Real-World Analysis of Post-Progression Treatment Patterns and Outcomes for EGFR Mutation-Positive Patients Treated with First-Line Osimertinib.

Introduction: The use of osimertinib in the first-line (1L) setting is an effective treatment option for sensitizing EGFR-mutations (EGFRm+) and has significantly altered the standard of care practice for EGFRm+ disease in Canada. Unfortunately, acquired resistance to osimertinib is almost universal, and outcomes are disparate. Post-progression treatment patterns and the outcome of real-world Canadian EGFRm+ patients receiving 1L osimertinib were the focus of this retrospective review. Methods: The Glans-Look Lung Cancer Research database was used to identify and collect demographic, clinical, treatment, and outcome data on EGFRm+ patients who received 1L osimertinib in the Canadian province of Alberta between 2018 and 2022. Results: A total of 150 patients receiving 1L osimertinib were identified. In total, 86 developed progressive disease, with 56 (65%) continuing systemic therapy, 73% continuing osimertinib, and 27% switching to second-line (2L) systemic therapy. Patients were similar both in clinical characteristics at 1L osimertinib initiation and patterns of treatment failure at progression; those continuing 1L osimertinib post-progression had a longer time to progression (13.5 vs. 8.8 months, p = 0.05) and subsequent post-osimertinib initiation survival (34.7 vs. 22.8 months, p = 0.11). Conclusions: The continuation of osimertinib post-progression is an effective disease management strategy for select real-world EGFRm+ patients, providing continued clinical benefit, potentially due to different underlying disease pathogenesis.

Stereotactic radiotherapy vs whole brain radiation therapy in EGFR mutated NSCLC: Results & reflections from the prematurely closed phase III HYBRID trial.

BACKGROUND: All known randomized trials of stereotactic radiotherapy (SRT) versus whole brain radiotherapy (WBRT) for brain metastases (BMs) comprise mixed histologies. The phase III HYBRID trial (NCT02882984) attempted to evaluate the non-inferiority of SRT vs. WBRT specifically for EGFR-mutated non-small cell lung cancer (EGFRm NSCLC) BMs. METHODS: Inclusion criteria were ≤ 5 BMs (any size) from treatment-naïve EGFRm NSCLC. All patients started a first-generation tyrosine kinase inhibitor on the first day of WBRT (37.5 Gy/15 fractions) or SRT (25-40 Gy/5 fractions per tumor volume). The primary endpoint was 18-month intracranial progression-free survival (iPFS; intention-to-treat). RESULTS: The trial commenced in June 2015 and was closed in April 2021 after screening 208 patients but enrolling 85 (n = 41 WBRT, n = 44 SRT; median follow-up 31 and 36 months, respectively). Respectively, 9.5 % vs. 10.2 % of patients experienced intracranial progression at 18 months, and the median iPFS was 21.4 vs. 22.3 months (p > 0.05 for all). The SRT arm experienced higher overall survival and cognitive preservation (p < 0.05 for all). The most notable reason for low enrollment was patients not wishing to risk neurocognitive decline from WBRT. CONCLUSIONS: Although this phase III trial was underpowered, there was no evidence that SRT yielded outcome detriments compared to WBRT for EGFRm NSCLC BMs. Lessons from prematurely closed trials are valuable, as they often provide important experiential perspectives for investigators designing/executing future trials. In the current era, randomized trials involving WBRT without cognitive sparing measures may be at high risk of underaccrual; trial investigators are encouraged to carefully consider our experience when attempting to design such trials. However, trials of molecular-/biologically-stratified patients are highly recommended as the notion of "individualized medicine/oncology" continues to expand.

Real-world outcomes on platinum-containing chemotherapy for EGFR-mutated advanced nonsquamous NSCLC with prior exposure to EGFR tyrosine kinase inhibitors.

Background: Front-line therapy with an EGFR tyrosine kinase inhibitor (TKI) is the standard of care for treating patients with advanced nonsquamous NSCLC with the common sensitizing EGFR exon 19 deletion and exon 21 L858R point mutations. However, EGFR TKI resistance inevitably develops. The optimal subsequent therapy remains to be identified, although platinum-containing chemotherapy regimens are often administered. Our objectives were to describe baseline characteristics, survival, and subsequent treatment patterns for patients with advanced nonsquamous NSCLC with EGFR exon 19 deletion or L858R mutation who received a platinum-based combination regimen after front-line EGFR TKI therapy. Methods: This retrospective study used a nationwide electronic health record-derived deidentified database to select adult patients with advanced nonsquamous NSCLC, evidence of EGFR exon 19 deletion or L858R mutation, and ECOG performance status of 0-2 who initiated platinum-containing chemotherapy, with or without concomitant immunotherapy, from 1-January-2011 to 30-June-2020 following receipt of any EGFR TKI as first-line therapy or, alternatively, a first- or second-generation EGFR TKI (erlotinib, afatinib, gefitinib, dacomitinib) as first-line therapy followed by the third-generation EGFR TKI osimertinib as second-line therapy. Data cut-off was 30-June-2022. The Kaplan-Meier method was used to estimate overall survival (OS) after initiation of pemetrexed-platinum (n=119) or any platinum-based combination regimen (platinum cohort; n=311). Results: The two cohorts included two-thirds women (65%-66%) and 57%-58% nonsmokers; median ages were 66 and 65 years in pemetrexed-platinum and platinum cohorts, respectively. Median OS was 10.3 months (95% CI, 8.1-13.9) from pemetrexed-platinum initiation and 12.4 months (95% CI, 10.2-15.2) from platinum initiation; 12-month survival rates were 48% and 51%, respectively; 260 patients (84%) had died by the end of the study. Conclusion: The suboptimal survival outcomes recorded in this study demonstrate the unmet need to identify more effective subsequent treatment regimens for patients with EGFR-mutated advanced nonsquamous NSCLC after EGFR TKI resistance develops.