Combination Therapy With MDM2 and MEK Inhibitors Is Effective in Patient-Derived Models of Lung Adenocarcinoma With Concurrent Oncogenic Drivers and MDM2 Amplification

IntroductionAlthough targeted therapies have revolutionized the therapeutic landscape of lung adenocarcinomas (LUADs), disease progression on single-agent targeted therapy against known oncogenic drivers is common, and therapeutic options after disease progression are limited. In patients with MDM2 amplification (MDM2amp) and a concurrent oncogenic driver alteration, we hypothesized that targeting of the tumor-suppressor pathway (by means of restoration of p53 using MDM2 inhibition) and simultaneous targeting of co-occurring MAPK oncogenic pathway might represent a more durably effective therapeutic strategy.MethodsWe evaluated genomic next-generation sequencing data using the Memorial Sloan Kettering Cancer Center-Integrated Mutation Profiling of Actionable Cancer Targets platform to nominate potential targets for combination therapy in LUAD. We investigated the small molecule MDM2 inhibitor milademetan in cell lines and patient-derived xenografts of LUAD with a known driver alteration and MDM2amp.ResultsOf 10,587 patient samples from 7121 patients with LUAD profiled by next-generation sequencing, 6% (410 of 7121) harbored MDM2amp. MDM2amp was significantly enriched among tumors with driver alterations in METex14 (36%, p < 0.001), EGFR (8%, p < 0.001), RET (12%, p < 0.01), and ALK (10%, p < 0.01). The combination of milademetan and the MEK inhibitor trametinib was synergistic in growth inhibition of ECLC5-GLx (TRIM33-RET/MDM2amp), LUAD12c (METex14/KRAS^G12S/MDM2amp), SW1573 (KRAS^G12C, TP53 wild type), and A549 (KRAS^G12S) cells and in increasing expression of proapoptotic proteins PUMA and BIM. Treatment of ECLC5-GLx and LUAD12c with single-agent milademetan increased ERK phosphorylation, consistent with previous data on ERK activation with MDM2 inhibition. This ERK activation was effectively suppressed by concomitant administration of trametinib. In contrast, ERK phosphorylation induced by milademetan was not suppressed by concurrent RET inhibition using selpercatinib (in ECLC5-GLx) or MET inhibition using capmatinib (in LUAD12c). In vivo, combination milademetan and trametinib was more effective than either agent alone in ECLC5-GLx, LX-285 (EGFRex19del/MDM2amp), L13BS1 (METex14/MDM2amp), and A549 (KRAS^G12S, TP53 wild type).ConclusionsCombined MDM2/MEK inhibition was found to have efficacy across multiple patient-derived LUAD models harboring MDM2amp and concurrent oncogenic drivers. This combination, potentially applicable to LUADs with a wide variety of oncogenic driver mutations and kinase fusions activating the MAPK pathway, has evident clinical implications and will be investigated as part of a planned phase 1/2 clinical trial.     

Clinical Impact of Hybrid Capture–Based Next-Generation Sequencing on Changes in Treatment Decisions in Lung Cancer

IntroductionTargeted therapy significantly prolongs survival in lung adenocarcinoma. Current diagnostic guidelines include only EGFR and anaplastic lymphoma receptor tyrosine kinase gene (ALK) testing. Next-generation sequencing (NGS) reveals more actionable genomic alterations than do standard diagnostic methods. Data on the influence of hybrid capture (HC)-based NGS on treatment are limited, and we investigated its impact on treatment decisions and clinical outcomes.MethodsThis retrospective study included patients with advanced lung cancer on whom HC-based NGS was performed between November 2011 and October 2015. Demographic and clinicopathologic characteristics, treatments, and outcome data were collected.ResultsA total of 101 patients were included (median age 63 years [53% females, 45% never-smokers, and 85% with adenocarcinoma]). HC-based NGS was performed upfront and after EGFR/ALK testing yielded negative or inconclusive results in 15% and 85% of patients, respectively. In 51.5% of patients, HC-based NGS was performed before first-line therapy, and in 48.5%, it was performed after treatment failure. HC-based NGS identified clinically actionable genomic alterations in 50% of patients, most frequently in EGFR (18%), Ret proto-oncogene (RET) (9%), ALK (8%), Mesenchymal-epithelial transition factor (MET) receptor tyrosine kinase gene (6%), and erb-b2 receptor tyrosine kinase 2 gene (ERBB2) (5%). In 15 patients, it identified EGFR/ALK aberrations after negative results of prior standard testing. Treatment strategy was changed for 43 patients (42.6%). The overall response rate in these patients was 65% (complete response 14.7%, partial response 50%). Median survival was not reached. Immunotherapy was administered in 33 patients, mostly without an actionable driver, with a presenting disease control rate of 32%, and with an association with tumor mutation burden.ConclusionsHC-based NGS influenced treatment decisions in close to half of the patients with lung adenocarcinoma and was associated with an overall response rate of 65%, which may translate into a survival benefit.     

RET Fluorescence In Situ Hybridization Analysis Is a Sensitive but Highly Unspecific Screening Method for RET Fusions in Lung Cancer

IntroductionRET gene fusions are established oncogenic drivers in 1% of NSCLC. Accurate detection of advanced patients with RET fusions is essential to ensure optimal therapy choice. We investigated the performance of fluorescence in situ hybridization (FISH) as a diagnostic test for detecting functional RET fusions.MethodsBetween January 2016 and November 2019, a total of 4873 patients with NSCLC were routinely screened for RET fusions using either FISH (n = 2858) or targeted RNA next-generation sequencing (NGS) (n = 2015). If sufficient material was available, positive cases were analyzed by both methods (n = 39) and multiple FISH assays (n = 17). In an independent cohort of 520 patients with NSCLC, whole-genome sequencing data were investigated for disruptive structural variations and functional fusions in the RET and compared with ALK and ROS1 loci.ResultsFISH analysis revealed RET rearrangement in 48 of 2858 cases; of 30 rearranged cases double tested with NGS, only nine had a functional RET fusion. RNA NGS yielded RET fusions in 14 of 2015 cases; all nine cases double tested by FISH had RET locus rearrangement. Of these 18 verified RET fusion cases, 16 had a split signal and two a complex rearrangement by FISH. By whole-genome sequencing, the prevalence of functional fusions compared with all disruptive events was lower in the RET (4 of 9, 44%) than the ALK (27 of 34, 79%) and ROS1 (9 of 12, 75%) loci.ConclusionsFISH is a sensitive but unspecific technique for RET screening, always requiring a confirmation using an orthogonal technique, owing to frequently occurring RET rearrangements not resulting in functional fusions in NSCLC.     

Immunotherapy Treatment Patterns and Outcomes Among ALK-Positive Patients With Non–Small-Cell Lung Cancer

IntroductionThe treatment landscape for anaplastic lymphoma kinase (ALK)-positive non–small-cell lung cancer (NSCLC) primarily involves ALK-directed tyrosine kinase inhibitors (TKIs). Although therapy with immune checkpoint inhibitors (ICIs) is a treatment option in NSCLC, the efficacy of ICI is inconclusive in ALK-positive NSCLC as a result of limited data. This retrospective real-world study sought to describe the characteristics of ALK-positive NSCLC patients treated with ICI and to assesses treatment outcomes in US oncology practices.Patients and MethodsThis analysis used the Flatiron Health electronic health record–derived deidentified database and included adult (18 years and older) ALK-positive advanced NSCLC patients with receipt of one or more ICIs after January 1, 2015. Median time to ICI discontinuation and real-world progression-free survival (rwPFS) were estimated by Kaplan-Meier methods.ResultsOf 83 patients with ALK-positive NSCLC treated with ICIs, 50.6% (n = 42) received ICI without a prior ALK TKI. Median time to ICI discontinuation was 2.17 months (95% confidence interval, 1.41, 3.32). The median rwPFS was 2.34 months (95% confidence interval, 1.55, 3.09); in patients who received an ICI without prior ALK TKI, it was 3.9 months, and in patients who received ICI therapy after an ALK TKI, it was 1.5 months.ConclusionsReal-world effectiveness (rwPFS) of ICIs in ALK-positive NSCLC patients, whether provided before or after TKIs, was limited, underscoring the relative lack of efficacy of ICI in this patient population, particularly compared to approved ALK TKIs.     

Immune checkpoint inhibitors for patients with advanced lung cancer and oncogenic driver alterations: results from the IMMUNOTARGET registry

BackgroundAnti-PD1/PD-L1 directed immune checkpoint inhibitors (ICI) are widely used to treat patients with advanced non-small-cell lung cancer (NSCLC). The activity of ICI across NSCLC harboring oncogenic alterations is poorly characterized. The aim of our study was to address the efficacy of ICI in the context of oncogenic addiction.Patients and methodsWe conducted a retrospective study for patients receiving ICI monotherapy for advanced NSCLC with at least one oncogenic driver alteration. Anonymized data were evaluated for clinicopathologic characteristics and outcomes for ICI therapy: best response (RECIST 1.1), progression-free survival (PFS), and overall survival (OS) from ICI initiation. The primary end point was PFS under ICI. Secondary end points were best response (RECIST 1.1) and OS from ICI initiation.ResultsWe studied 551 patients treated in 24 centers from 10 countries. The molecular alterations involved KRAS (n = 271), EGFR (n = 125), BRAF (n = 43), MET (n = 36), HER2 (n = 29), ALK (n = 23), RET (n = 16), ROS1 (n = 7), and multiple drivers (n = 1). Median age was 60 years, gender ratio was 1 : 1, never/former/current smokers were 28%/51%/21%, respectively, and the majority of tumors were adenocarcinoma. The objective response rate by driver alteration was: KRAS = 26%, BRAF = 24%, ROS1 = 17%, MET = 16%, EGFR = 12%, HER2 = 7%, RET = 6%, and ALK = 0%. In the entire cohort, median PFS was 2.8 months, OS 13.3 months, and the best response rate 19%. In a subgroup analysis, median PFS (in months) was 2.1 for EGFR, 3.2 for KRAS, 2.5 for ALK, 3.1 for BRAF, 2.5 for HER2, 2.1 for RET, and 3.4 for MET. In certain subgroups, PFS was positively associated with PD-L1 expression (KRAS, EGFR) and with smoking status (BRAF, HER2).Conclusions: ICI induced regression in some tumors with actionable driver alterations, but clinical activity was lower compared with the KRAS group and the lack of response in the ALK group was notable. Patients with actionable tumor alterations should receive targeted therapies and chemotherapy before considering immunotherapy as a single agent.     

Small-Cell Lung Cancer Transformation as a Mechanism of Resistance to Pralsetinib in RET-Rearranged Lung Adenocarcinoma: A Case Report

The majority of resistance to Rearranged during transfection (RET)-specific tyrosine kinase inhibitors (TKI) described in RET-rearranged non-small cell lung cancer (NSCLC) patients are driven by RET-independent mechanisms. We provide the first case report of a RET-rearranged lung adenocarcinoma (LUAD) transformation into small-cell lung cancer (SCLC) as a mechanism of acquired resistance to pralsetinib. A 43-year-old patient presented with a RET-rearranged LUAD revealed by pleural effusion. After 14 months of response to pralsetinib, biopsy of a progressive pleural lesion found a phenotypic transformation into SCLC. Molecular analysis identified the same RET fusion and TP53 mutation in both primary adenocarcinoma and recurrence as SCLC. The patient achieved partial response after switch to carboplatin and etoposide chemotherapy and presented with progression disease after 6 months. Histological transformation could be a mechanism of resistance to RET-TKIs and rebiopsy should be considered to adapt subsequent treatment.     

Clinical outcomes with pemetrexed-based systemic therapies in RET-rearranged lung cancers

BackgroundRET rearrangements are targetable, oncogenic lung cancer drivers. While previous series have shown durable clinical benefit with pemetrexed-based therapies in ALK- and ROS1-rearranged lung cancers, the benefits of pemetrexed-based treatments in patients with RET-rearranged lung cancers relative to other genomic subsets have not previously been explored.Patients and methodsA retrospective review of patients with pathologically confirmed stage IIIB/IV lung adenocarcinomas and evidence of a RET, ROS1, or ALK rearrangement, or a KRAS mutation was conducted. Patients were eligible if they received treatment with pemetrexed alone or in combination. The primary outcome of progression-free survival (PFS), and secondary outcomes of overall response rate (ORR, RECIST v1.1), time to progression (TTP), and time to treatment discontinuation were compared between RET-rearranged and groups of ROS1-rearranged, ALK-rearranged, and KRAS-mutant lung cancers.ResultsWe evaluated 104 patients. Patients with RET-rearranged lung cancers (n = 18) had a median PFS of 19 months [95% confidence interval (CI) 12–not reached (NR)] that was comparable with patients with ROS1- (23 months, 95% CI 14–NR, n = 10) and ALK-rearranged (19 months, 95% CI 15–36, n = 36) lung cancers, and significantly improved compared with patients with KRAS-mutant lung cancers (6 months, 95% CI 5–9, P < 0.001, n = 40). ORR (45%), median TTP (20 months, 95% CI 17–NR), and median time to treatment discontinuation (21 months, 95% CI 6–NR) in patients with RET-rearranged lung cancers were not significantly different compared with patients with ALK- and ROS1-rearranged lung cancers, and improved compared with patients with KRAS-mutant lung cancers.ConclusionDurable benefits with pemetrexed-based therapies in RET-rearranged lung cancers are comparable with ALK- and ROS1-rearranged lung cancers. When selecting therapies for patients with RET-rearranged lung cancers, pemetrexed-containing regimens should be considered.     

Benefit of Targeted DNA Sequencing in Advanced Non–Small-Cell Lung Cancer Patients Without EGFR and ALK Alterations on Conventional Tests

BackgroundGenetic sequencing testing has become widely used to inform treatment decisions for advanced non–small-cell lung cancer (NSCLC) patients. We analyzed benefits of genetic sequencing testing in real practice.Patients and MethodsWe retrospectively reviewed 209 NSCLC patients who had no EGFR and ALK alterations on routine molecular tests and underwent next-generation targeted DNA sequencing of 380 cancer-related genes between November 2013 and October 2016. Median patient age was 59 years. A total of 96 patients (46%) were never smokers, and 195 patients (93%) had adenocarcinoma.ResultsAmong 209 total patients, 64 (31%) demonstrated actionable genetic alterations; 20 had EGFR mutations (6 L858R, 8 exon 19 deletions, 1 L861Q, 1 G719S, 4 exon 20 duplications), 4 ALK fusions, 9 ROS1 fusions, 6 BRAF V600E mutations, 15 RET fusions, 1 MET high-level amplification, 6 MET exon 14 skipping mutations, and 3 ERBB2 exon 20 insertion mutations. Of the 64 patients harboring actionable alterations, 28 patients received therapy targeted to their own actionable alterations (15 EGFR, 3 ALK, 1 ROS1, 8 RET, 1 BRAF). There were significant differences in overall survival between individuals with no actionable alterations, those with actionable alterations but no targeted therapy, and those with actionable alterations and targeted therapy (20.1 vs. 17.1 vs. 66.2 months, P < .001).ConclusionThe results of targeted DNA sequencing testing could provide improved treatment options for some NSCLC patients and result in a survival benefit to NSCLC patients with no EGFR and ALK alterations on routine tests who are treated with targeted therapy.     

Identification of Novel CD74-NRG2α Fusion From Comprehensive Profiling of Lung Adenocarcinoma in Japanese Never or Light Smokers

IntroductionStudies are yet to characterize the differences in molecular profiles of lung adenocarcinoma (LUAD) among divergent ethnic groups. Herein, we conducted comprehensive molecular profiling of LUAD in never or light smokers from Asia to discover novel targetable mutations and prognostic biomarkers of this distinct disease entity.MethodsWe analyzed 996 cases of Japanese LUAD and performed whole-exome sequencing and RNA-seq in 125 cases of Japanese LUAD negative for the driver oncogenes defined by conventional laboratory testing. We also investigated the clinical and pathologic characteristics among the 996 cases.ResultsDriver oncogenes were identified in 88 cases (70.4%) with specific hotspot mutations differing from those in The Cancer Genome Atlas study. Two actionable novel fusions of FGFR2 and NRG2α were also identified. Clustering on the basis of mRNA expression profiles, but not genetic mutational ones, could predict patient prognosis. The risk score generated by the expression of a three-gene set was a strong prognostic marker for overall survival and progression-free survival in our cohort, and was further validated using The Cancer Genome Atlas cohort. Among the 996 cases, each driver alteration is distributed across all histologic subtypes. Adenocarcinoma in situ was identified to harbor driver mutations, suggesting that these alterations are early events in the pathogenesis of LUAD. ERBB2 mutations were over-represented in young adults.ConclusionsThis study indicates the value of applying gene expression profiling for predicting the prognosis after a surgical operation, and that the identification of actionable mutations is important for optimizing targeted drugs in Japanese LUAD.     

Expression Profiling of Driver Genes in Female Never-smokers With Non-adenocarcinoma Non–small-cell Lung Cancer in China

BackgroundAlthough smoking is a primary cause of lung cancer, females are overrepresented among never-smokers with the disease. The mutational landscape of adenocarcinoma in never-smoking females has been extensively profiled; however, there is little knowledge about genomic alterations in non-adenocarcinoma non–small-cell lung cancer (NA-NSCLC). In the study, we reviewed the status of oncogenic drivers of NA-NSCLC in these populations.Materials and MethodsComprehensive genomic profiling was performed on DNA extracted from formalin-fixed, paraffin-embedded sections of 52 NA-NSCLC tissues, including 35 squamous cell carcinomas (SQCCs), 11 adenosquamous carcinomas, 5 pulmonary sarcomatoid carcinoma, and 1 large cell carcinoma by next-generation sequencing within a panel of 68 cancer-related genes.ResultsMutations of the common oncogenic drivers (EGFR, KRAS, ALK, ROS1, MET, RET, and ERBB2) occurred in 61.5% of cases. The frequency of well-established targets (EGFR and ALK), new targets without widely available therapies (MET and ERBB2), and potentially actionable targets (RET and DDR2) in SQCCs of female never-smokers was significantly higher than that in The Cancer Genome Atlas dataset. There were 31%, 82%, and 80% of cases with SQCC, adenosquamous carcinoma, and pulmonary sarcomatoid carcinoma, respectively, harboring at least one of the following targets: EGFR, ALK, ERBB2, and MET. Approximately 78% (7/9) of the patients responded to various targeted treatments.ConclusionFemale never-smokers with NA-NSCLC in this study had a high frequency of currently known or potentially actionable oncogenic alterations and could benefit from targeted therapy. Our study also provides evidence for the recommendation of molecular analysis in never-smoking female SQCC.     

Programmed Death-Ligand 1 Tumor Proportion Score and Overall Survival From First-Line Pembrolizumab in Patients With Nonsquamous Versus Squamous NSCLC

IntroductionFor patients with NSCLC receiving immune checkpoint inhibitors, programmed death-ligand 1 (PD-L1) tumor proportion score (TPS) has been validated as a predictive biomarker for improved overall survival (OS). Nevertheless, its histology-specific predictive value in patients with advanced squamous versus nonsquamous cancers remains unclear. To evaluate the differential value of PD-L1 TPS as a predictive biomarker for OS after first-line pembrolizumab in patients with squamous versus nonsquamous NSCLC.MethodsRetrospective, observational study of patients diagnosed with having advanced NSCLC who were treated between October 2015 and April 2019 at community oncology clinics and academic medical centers in a deidentified electronic health record–derived database. Included patients were diagnosed with having advanced or metastatic NSCLC, received treatment with first-line, single-agent pembrolizumab, and had documentation of PD-L1 testing with a numeric result. Exclusion criteria included alterations in EGFR, ALK, and ROS1. The primary end point was OS from start of first-line pembrolizumab therapy by squamous or nonsquamous histology and PD-1 expression level measured by TPS (low, <50% or high, ≥50%).ResultsThe cohort of 1460 patients with NSCLC who received pembrolizumab as a first-line therapy had a mean age of 72 years. Histology was 28% squamous and 72% nonsquamous. PD-L1 expression was low in 13% and high in 87%. No meaningful differences in age, sex, or smoking history were observed by PD-L1 TPS or histology type. A generalized gamma model adjusting for sex and stage at diagnosis found that for patients with nonsquamous histology, high PD-L1 TPS was significantly associated with improved OS by a median OS difference of 8.4 months (p < 0.001). In contrast, for patients with squamous histology, there was no evidence of association between PD-L1 expression level and OS (p = 0.283). PD-L1–related incremental differences in median OS between the patients with squamous and nonsquamous tumors were significantly different (p = 0.034).ConclusionsAmong patients with NSCLC treated with first-line pembrolizumab, high PD-L1 TPS is associated with OS among patients with nonsquamous NSCLC, but not among patients with squamous NSCLC.     

Treatment Rationale and Design for APPLE (WJOG11218L): A Multicenter,Open-Label,Randomized Phase 3 Study of Atezolizumab and Platinum/Pemetrexed With or Without Bevacizumab for Patients With Advanced Nonsquamous Non–Small-Cell Lung Cancer

BackgroundFirst-line treatment of non–small-cell lung cancer (NSCLC) has undergone a paradigm shift to platinum combination therapy together with an immune checkpoint inhibitor (ICI). Bevacizumab is expected to enhance not only chemotherapy but also the efficacy of ICIs through blockade of vascular endothelial growth factor–mediated immunosuppression. We have now designed a randomized phase 3 study (APPLE, WJOG11218L, JapicCTI-194565) to evaluate the additional effect of bevacizumab administered together with platinum combination therapy and the ICI atezolizumab in patients with advanced nonsquamous NSCLC.Patients and MethodsCytotoxic chemotherapy–naive patients aged 20 years or older with a performance status of 0 or 1 are randomly assigned in a 1:1 ratio to receive either atezolizumab plus pemetrexed/carboplatin or atezolizumab, pemetrexed/carboplatin, and bevacizumab. Patients with genetic driver alterations such as those affecting EGFR or ALK are included if they have experienced disease progression or unacceptable adverse effects during treatment with at least one approved tyrosine kinase inhibitor. After 4 cycles of induction therapy, maintenance therapy with atezolizumab plus pemetrexed or with atezolizumab, pemetrexed, and bevacizumab is administered for up to 2 years until evidence of disease progression or development of unacceptable toxicity. The primary end point is progression-free survival.ConclusionThis is a phase 3 study to investigate the effect of adding bevacizumab to an ICI and platinum/pemetrexed combination therapy. If the primary objective is achieved, this study will provide a new standard treatment for cytotoxic chemotherapy–naive patients with advanced nonsquamous NSCLC.     

RET-MAP: An International Multicenter Study on Clinicobiologic Features and Treatment Response in Patients With Lung Cancer Harboring a RET Fusion

IntroductionNearly 1% to 2% of NSCLCs harbor RET fusions. Characterization of this rare population is still incomplete.MethodsThis retrospective multicenter study included patients with any-stage RET positive (RET+) NSCLC from 31 cancer centers. Molecular profiling included DNA/RNA sequencing or fluorescence in situ hybridization analyses. Clinicobiological features and treatment outcomes (per investigator) with surgery, chemotherapy (CT), immune checkpoint blockers (ICBs), CT-ICB, multityrosine kinase inhibitors, and RET inhibitors (RETis) were evaluated.ResultsFor 218 patients included between February 2012 and April 2022, median age was 63 years, 56% were females, 93% had adenocarcinoma, and 41% were smokers. The most frequent fusion partner was KIF5B (72%). Median tumor mutational burden was 2.5 (range: 1–4) mutations per megabase, and median programmed death-ligand 1 expression was 10% (range: 0%–55%). The most common metastatic sites were the lung (50%), bone (43%), and pleura (40%). Central nervous system metastases were found at diagnosis of advanced NSCLC in 21% of the patients and at last follow-up or death in 31%. Overall response rate and median progression-free survival were 55% and 8.7 months with platinum doublet, 26% and 3.6 months with single-agent CT, 46% and 9.6 months with CT-ICB, 23% and 3.1 months with ICB, 37% and 3 months with multityrosine kinase inhibitor, and 76% and 16.2 months with RETi, respectively. Median overall survival was longer in patients treated with RETi versus no RETi (50.6 mo [37.7–72.1] versus 16.3 mo [12.7–28.8], p < 0.0001).ConclusionsPatients with RET+ NSCLC have mainly thoracic and bone disease and low tumor mutational burden and programmed death-ligand 1 expression. RETi markedly improved survival, whereas ICB may be active in selected patients.     

RET-Rearranged Lung Adenocarcinomas with Lymphangitic Spread,Psammoma Bodies,and Clinical Responses to Cabozantinib

Oncogenic rearrangements of the RET gene have recently been described in 1% to 2% of lung adenocarcinomas. We report five cases of RET-rearranged lung adenocarcinoma with an unusual constellation of clinical and histologic features that has not previously been described in tumors with this genomic alteration. The age at diagnosis of the five patients (4F, 1M) ranged from 44 to 77 years. All were never-smokers. Radiologically, four tumors showed lymphangitic spread within the lungs at presentation; three of these had multiple bilateral lung nodules. Histology showed psammoma bodies within the tumor in four of five cases. Molecular testing for activating EGFR mutations by standard genotyping and ALK expression by immunohistochemistry was negative in all cases. Additional molecular analysis was prompted by the clinical profile in that all five patients were never-smokers with metastatic, relapsed, and/or refractory disease; and also by unusual histologic findings in two cases. Comprehensive genomic profiling performed by means of a clinical grade cancer gene panel next-generation sequencing assay demonstrated a KIF5B-RET fusion in three; and fluorescence in-situ hybridization documented a RET rearrangement in two. Three of the patients were treated with the RET inhibitor cabozantinib. By Response Evaluation Criteria In Solid Tumors (RECIST) criteria, two had a confirmed partial response (at 6 weeks and 4 weeks) and one had stable disease. Our findings suggest that the combination of lymphangitic spread and psammoma bodies may be characteristic of a subset of advanced stage RET-rearranged lung adenocarcinomas. These findings should prompt additional molecular testing for RET translocations, particularly in never-smokers with EGFR- and ALK-negative lung adenocarcinoma.     

Multiplex genomic profiling of non–small cell lung cancers from the LETS phase III trial of first-line S-1/carboplatin versus paclitaxel/carboplatin: results of a West Japan Oncology Group study

Archival formalin-fixed, paraffin-embedded (FFPE) tumor specimens were collected from advanced NSCLC patients enrolled in LETS phase III trial comparing first-line S-1/carboplatin with paclitaxel/carboplatin and subjected to multiplex genotyping for 214 somatic hotspot mutations in 26 genes (LungCarta Panel) and 20 major variants of ALK, RET, and ROS1 fusion genes (LungFusion Panel) with the Sequenom MassARRAY platform. MET amplification was evaluated by fluorescence in situ hybridization. A somatic mutation in at least one gene was identified in 48% of non–squamous cell carcinoma and 45% of squamous cell carcinoma specimens, with EGFR (17%), TP53 (11%), STK11 (9.8%), MET (7.6%), and KRAS (6.2%). Mutations in EGFR or KRAS were associated with a longer or shorter median overall survival, respectively. The LungFusion Panel identified ALK fusions in six cases (2.5%), ROS1 fusions in five cases (2.1%), and a RET fusion in one case (0.4%), with these three types of rearrangement being mutually exclusive. Nine (3.9%) of 229 patients were found to be positive for de novo MET amplification. This first multiplex genotyping of NSCLC associated with a phase III trial shows that MassARRAY-based genetic testing for somatic mutations and fusion genes performs well with nucleic acid derived from FFPE specimens of NSCLC tissue.     

Genomic landscape of metastatic lung adenocarcinomas from large-scale clinical sequencing

Background: Metastases are responsible for over 70% of deaths from lung adenocarcinomas. Previous large-scale studies of LUAD mainly focused on primary diseases. We aimed to comprehensively analyze the genomic landscape of metastatic LUADs and elucidate its clinical implications in the context of precision medicine.Methods: We performed retrospective analyses on targeted sequencing data of 3,743 primary tumors and 934 metastases from 4,480 patients with lung adenocarcinomas, and PD-L1 immunohistochemical data of 1,336 primary tumors and 252 metastases from 1,588 LUAD patients.Results: Metastases generally manifested significantly higher mutational burdens and chromosomal instability than primary lung adenocarcinomas. Clinically actionable alterations, including ALK mutations, ALK and ROS1 fusions, and MET copy number gains, were enriched in metastases, particularly metastases to some specific organs/tissues, such as lymph nodes, liver, and brain. PD-L1 expression decreased as the approximate metastatic distance increased. Additional data of paired primary tumors and metastases to lymph nodes and brain validated patterns of actionable alterations and candidates for metastatic drivers. Two evolutionary modes of metastatic dissemination, common origins and distinct origins, were identified in both types of primary-metastasis pairs.Conclusions: Our study showed heterogenous patterns of clinically actionable alterations, PD-L1 expressions, metastatic driver candidates, and evolutionary patterns among multiple types of metastases of lung adenocarcinomas, which may advise the planning of treatments and the identification of novel therapeutic targets.     

Advanced-Stage Non–Small Cell Lung Cancer: Advances in Thoracic Oncology 2018

In 2018 research in the field of advanced NSCLCs led to an expanded reach and impact of immune checkpoint inhibitors (ICIs) as part of a frontline treatment strategy, regardless of histologic subtype, with ICI use extended to include stage III disease, shifting the prognosis of all these patients. This new standard first-line approach opens a gap in standard second-line treatment, and older combinations may again become standard of care after progression during treatment with an ICI. The characterization of predictive biomarkers, patient selection, the definition of strategies with ICI combinations upon progression during treatment with ICIs, as well as prospective evaluation of the efficacy of ICIs in subpopulations (such as patients with poor performance status or brain metastases) represent upcoming challenges in advanced thoracic malignancies. In oncogene-addicted NSCLC three major steps were taken during 2018: next-generation tyrosine kinase inhibitors have overtaken more established agents as the new standard of care in EGFR and ALK receptor tyrosine kinase gene (ALK)-positive tumors. Mechanisms of acquired resistance have been reported among patients treated with next-generation EGFR tyrosine kinase inhibitors, reflecting the diversity of the landscape. One major step forward was the approval of personalized treatment in very uncommon genomic alterations, mainly fusions. This raises a new question about the challenge of implementation of next-generation sequencing in daily clinical practice to detect new and uncommon genomic alterations and to capture the heterogeneity of the mechanisms of acquired resistance during treatment, as well as the need to extend research into new therapeutic strategies to overcome them.