From Cancer to Immune Organoids: Innovative Preclinical Models to Dissect the Crosstalk between Cancer Cells and the Tumor Microenvironment.

Genomic-oriented oncology has improved tumor classification, treatment options, and patient outcomes. However, genetic heterogeneity, tumor cell plasticity, and the ability of cancer cells to hijack the tumor microenvironment (TME) represent a major roadblock for cancer eradication. Recent biotechnological advances in organotypic cell cultures have revolutionized biomedical research, opening new avenues to explore the use of cancer organoids in functional precision oncology, especially when genomics alone is not a determinant. Here, we outline the potential and the limitations of tumor organoids in preclinical and translational studies with a particular focus on lung cancer pathogenesis, highlighting their relevance in predicting therapy response, evaluating treatment toxicity, and designing novel anticancer strategies. Furthermore, we describe innovative organotypic coculture systems to dissect the crosstalk with the TME and to test the efficacy of different immunotherapy approaches, including adoptive cell therapy. Finally, we discuss the potential clinical relevance of microfluidic mini-organ technology, capable of reproducing tumor vasculature and the dynamics of tumor initiation and progression, as well as immunomodulatory interactions among tumor organoids, cancer-associated fibroblasts (CAFs) and immune cells, paving the way for next-generation immune precision oncology.

CT-Guided Core Needle Biopsy of Pulmonary Lesions Associated With Cystic Airspaces: A Case-Control Study.

BACKGROUND. Concern may exist that pulmonary lesions associated with cystic airspaces are at risk of increased biopsy complications or lower biopsy accuracy given challenges in targeting tissue abutting or intermingled with the cystic airspaces. OBJECTIVE. The purpose of this study was to evaluate the safety and diagnostic performance of CT-guided core needle biopsy (CNB) of pulmonary lesions associated with cystic airspaces. METHODS. This retrospective study included 90 patients (median age, 69.5 years; 28 women, 62 men) who underwent CT-guided CNB of pulmonary lesions associated with cystic airspaces (based on review of procedural images) from February 2010 to December 2022 and a matched control group (2:1 ratio) of 180 patients (median age, 68.0 years; 56 women, 124 men) who underwent CNB of noncystic noncavitary lesions during the same period. The groups were compared in terms of complications, nondiagnostic biopsies (i.e., nonspecific benignities, atypical cells, or insufficient specimens), and CNB diagnostic performance for detecting malignancy using as reference the final diagnosis from a joint review of all available records. For lesions associated with cystic airspaces that underwent surgical resection after CNB, histologic slides were reviewed to explore the nature of the cystic airspace. RESULTS. The final diagnosis was malignant in 90% (81/90) of lesions associated with cystic airspaces and 92% (165/180) of noncystic noncavitary lesions. Patients with lesions associated with cystic airspaces and patients with noncystic noncavitary lesions showed no significant difference in frequency of complications (overall: 40% [36/90] vs 38% [68/180], p = .79; major: 4% [4/90] vs 6% [10/180], p = .78; minor: 36% [32/90] vs 32% [58/180], p = .59), frequency of nondiagnostic biopsies (12% [11/90] vs 9% [16/180], p = .40), or diagnostic performance (accuracy: 94% [85/90] vs 97% [175/180], p = .50; sensitivity: 94% [76/81] vs 97% [160/165], p = .50; specificity: 100% [9/9] vs 100% [15/15]; p > .99), respectively. All false-negative results for malignancy in both groups occurred in patients with nondiagnostic CNB results. Among lesions associated with cystic airspaces that were resected after CNB (all malignant), the cystic airspaces most commonly represented tumor degeneration (22/31 [71%]). CONCLUSION. CT-guided CNB is safe and accurate for assessing pulmonary lesions associated with cystic airspaces. CLINICAL IMPACT. CNB may help avoid a missed or delayed cancer diagnosis in pulmonary lesions with cystic airspaces.

A case series of non-small cell lung cancer patients with EGFR or HER2 exon 20 insertion in Li Fraumeni syndrome.

INTRODUCTION: Germline pathogenic mutations in TP53 gene are associated with a cancer predisposition syndrome known as Li Fraumeni syndrome. Albeit infrequently, non-small cell lung cancer, especially as oncogene-addicted disease, may be diagnosed in young patients with Li Fraumeni syndrome. CASE DESCRIPTION: We report three cases of patients affected by Li Fraumeni syndrome who developed non-small cell lung cancer with EGFR or HER2 exon 20 insertions. The first patient suffered from liposarcoma and, then, brain metastases from HER2-mutated non-small cell lung cancer: after stereotactic radiotherapy, he benefited from enrollment in a clinical trial with a HER2-targeted therapy. The second young patient was a female with personal history of rhabdomyosarcoma, diagnosed with brain metastases from EGFR-mutated non-small cell lung cancer: enrollment in a clinical trial led to a temporary clinical benefit. The last case was a female diagnosed with breast carcinoma, ovarian granulosa cell tumor and advanced EGFR-mutated non-small cell lung cancer at a young age. CONCLUSIONS: Young patients affected by oncogene-addicted non-small cell lung cancer and with a positive familial cancer history should be referred for an accurate genetic counselling to look for Li Fraumeni syndrome. The underlying molecular connection between TP53 and HER family receptor tyrosine kinases remains unclear, but an extensive molecular characterization of tumors from patients with Li Fraumeni syndrome should always be performed, to offer patients a personalized therapeutic approach.

BAP1 Loss, Nuclear Grading, and Nonepithelioid Features in the Diagnosis of Mesothelioma in Italy: Nevermore without the Pathology Report.

The pathologic diagnosis of pleural mesothelioma is generally based on international guidelines, but no compulsory points based on different drugs approvals in different European countries are required to be reported. According to the last (2021) edition of the World Health Organization classification of pleural tumors, the nuclear grade of epithelioid-type mesothelioma should be always inserted in the pathologic report, while the presence of BRCA-associated protein-1 (BAP1) (clone C4) loss and a statement on the presence of the sarcomatoid/nonepithelioid component are fundamental for both a screening of patients with suspected BAP1 tumor predisposition syndrome and the eligibility to perform first-line immunotherapy at least in some countries. Several Italian experts on pleural mesothelioma who are deeply involved in national scientific societies or dedicated working groups supported by patient associations agreed that the pathology report of mesothelioma of the pleura should always include the nuclear grade in the epithelioid histology, which is an overt statement on the presence of sarcomatoid components (at least 1%, in agreement with the last classification of pleural mesothelioma) and the presence of BAP1 loss (BAP1-deficient mesothelioma) or not (BAP1-retained mesothelioma) in order to screen patients possibly harboring BAP1 tumor predisposition syndrome. This review aims to summarize the most recent data on these three important elements to provide evidence regarding the possible precision needs for mesothelioma.

Lung Cancer Related Thrombosis (LCART): Focus on Immune Checkpoint Blockade.

Cancer-associated thrombosis (CAT) is a common complication in lung cancer patients. Lung cancer confers an increased risk of thrombosis compared to other solid malignancies across all stages of the disease. Newer treatment agents, including checkpoint immunotherapy and targeted agents, may further increase the risk of CAT. Different risk-assessment models, such as the Khorana Risk Score, and newer approaches that incorporate genetic risk factors have been used in lung cancer patients to evaluate the risk of thrombosis. The management of CAT is based on the results of large prospective trials, which show similar benefits to low-molecular-weight heparins (LMWHs) and direct oral anticoagulants (DOACs) in ambulatory patients. The anticoagulation agent and duration of therapy should be personalized according to lung cancer stage and histology, the presence of driver mutations and use of antineoplastic therapy, including recent curative lung surgery, chemotherapy or immunotherapy. Treatment options should be evaluated in the context of the COVID-19 pandemic, which has been shown to impact the thrombotic risk in cancer patients. This review focuses on the epidemiology, pathophysiology, risk factors, novel predictive scores and management of CAT in patients with active lung cancer, with a focus on immune checkpoint inhibitors.

Epigenetic determinants in soft tissue sarcomas: molecular mechanisms and therapeutic targets.

INTRODUCTION: Soft tissue sarcomas are a group of rare, mesenchymal tumors characterized by dismal prognosis in advanced/metastatic stages. Knowledge of their molecular determinants is still rather limited. However, in recent years, epigenetic regulation - the modification of gene expression/function without DNA sequence variation - has emerged as a key player both in sarcomagenesis and sarcoma progression. AREAS COVERED: Herein, we describe and review the main epigenetic mechanisms involved in chromatin remodeling and their role as disease drivers in different soft tissue sarcoma histotypes, focusing on epithelioid sarcoma, synovial sarcoma, and malignant peripheral nerve sheath tumors. Focusing on chromatin-remodeling complexes, we provide an in-depth on the role of BAF complex alterations in these soft tissue sarcoma histotypes. In parallel, we highlight current state-of-the-art and future perspectives in the development of rational, innovative treatments leveraging on epigenetic dysregulation in soft tissue sarcomas. EXPERT OPINION: Therapeutic options for metastatic/advanced sarcomas are to date very limited and largely represented by cytotoxic agents, with only modest results. In the continuous attempt to find novel targets and innovative, effective drugs, epigenetic mechanisms represent an emerging and promising field of research, especially for malignant peripheral nerve sheath tumors, epithelioid and synovial sarcoma.

Meta-Analysis on the Combination of Chemotherapy With Programmed Death-Ligand 1 and Programmed Cell Death Protein 1 Blockade as First-Line Treatment for Unresectable Pleural Mesothelioma.

INTRODUCTION: Dual immune checkpoint blockers regimen represents a standard first-line therapy in unresectable pleural mesothelioma (PM). Novel combination strategies, including immune checkpoint blockers and antiangiogenic drugs, are currently under investigation in this setting. We aimed to assess the efficacy of the chemoimmunotherapy combination by reference to literature evidence. METHODS: A systematic review and meta-analysis of trials with first-line platinum-based chemotherapy associated with programmed death-ligand 1 and programmed cell death protein 1 agent in unresectable PM. We estimated the weighted summary proportion of disease response, along with the landmark probability of survival outcomes. RESULTS: A total of 349 patients with unresectable PM from four trials (DREAM, PrE0505, JME-001, and IND.227) were included, 79% (n = 274) with epithelioid and 21% (n = 75) with nonepithelioid histologic type. In aggregate, the objective response rate was 59.2% (95% confidence interval [CI]: 50.3%-67.9%) and disease control rate was 92.2% (95% CI: 89.2%-94.8%). Comparing epithelioid versus nonepithelioid tumors, the objective response rate was 64.5% versus 46.4%, (p < 0.001) and the disease control rate was 92.3% versus 80.0%, (p = 0.043), with an OR of 2.56 (95% CI: 1.51-4.32) for disease response and of 3.37 (95% CI: 0.99-11.47) for disease control. The aggregated estimated probability of progression-free survival was 63% (95% CI: 53%-71%) at 6 months and 25% (95% CI: 21%-31%) at 12 months, whereas the 6-, 12- and 24-month overall survival rates were 88% (95% CI: 81%-93%), 71% (95% CI: 61%-79%) and 39% (95% CI: 34%-45%), respectively. CONCLUSIONS: According to our analysis, first-line chemoimmunotherapy holds promise as a new treatment approach for PM, exhibiting encouraging survival outcomes and an enhanced response rate, including for the epithelioid subtype. Ongoing studies are necessary to establish its precise placement within the treatment algorithm.

Clinical evidence and adverse event management update of patients with RET- rearranged advanced non-small-cell lung cancer (NSCLC) treated with pralsetinib.

Current non-small cell lung cancer (NSCLC) management relies on genome-driven precision oncology thus shifting treatment paradigm towards biomarker-guided tumor-agnostic approaches. Recently, rearranged during transfection (RET) has been endorsed as tissue-agnostic target with sensitivity to RET inhibition. There are currently two selective RET tyrosine kinase inhibitors, pralsetinib and selpercatinib. The recent introduction of pralsetinib in the treatment algorithm of RET-rearranged tumor along with the mounting clinical evidence of pralsetinib durable activity from both randomized and observational studies holds the potential to disclose new avenues in the management of RET fusion positive NSCLC patients. Our narrative review aims to discuss the available clinical evidence on pralsetinib efficacy, particularly on brain metastases, and tolerability profile. In addition, our work explores the relevance of detecting RET fusions upfront in the disease history of patients with NSCLC.

Niraparib plus Dostarlimab in Pleural Mesothelioma or Non-Small Cell Lung Cancer Harboring HRR Mutations: Interim Results of the UNITO-001 Phase II Prospective Trial.

PURPOSE: Treatment of homologous recombination repair-deficient (HRD)-tumors with PARP inhibitors has the potential to further increase tumor immunogenicity, suggesting a synergistic effect with immunotherapy. Here we present the preliminary results of niraparib in combination with dostarlimab for pleural mesothelioma (PM) or non-small cell lung cancer (NSCLC) harboring HRR mutations. PATIENTS AND METHODS: UNITO-001 is a phase II, prospective, study aiming to investigate the combination of niraparib plus dostarlimab in pretreated patients with HRD and programmed death ligand-1 (PD-L1) ≥1% NSCLC and/or PM. The primary endpoint is progression-free survival (PFS). RESULTS: Seventeen of 183 (10%) screened patients (12 PM and 5 NSCLC) were included. The objective response rate (ORR) was 6% [95% confidence interval (CI): 0.1-28.7] and the disease control rate (DCR) was 53% (95% CI: 27.8-77). Median PFS was 3.1 (95% CI: 2.7-N.A) and median overall survival (OS) was 4.2 (95% CI: 1.58-NA) months. The PFS was 14.1 months in one PM patient harboring a germline BAP1 mutation. The treatment duration was 9.8 months in one PM patient harboring a somatic BRCA2 mutation. The most common adverse events (AE) were grade 1-2 lymphopenia (59%), anemia (35%), hyponatremia (29%), and hypokalemia (29%). Grade ≥3 AEs were reported in 23% of the patients. CONCLUSIONS: This preliminary analysis highlighted the lack of antitumor activity for the combination of niraparib and dostarlimab in patients with PM and/or advanced NSCLC harboring BAP1 somatic mutations. A potential antitumor activity emerged for PM with germline BAP1 and/or BRCA2 somatic mutations along with a good tolerability profile.

Sharing Experience with Anaplastic Lymphoma Kinase Tyrosine Kinase Inhibitors in Lung Cancer: An Italian Expert Panel Discussion.

BACKGROUND: ALK tyrosine kinase inhibitors (TKIs) have revolutionized the treatment and largely improved the survival outcomes of patients with NSCLC harboring ALK rearrangements. Different ALK TKI compounds have demonstrated antitumor activity in these patients and are available in clinical practice. However, clinical expertise across countries varies according to local regulatory approval of different drugs, identifying multiple treatment scenarios to comply with international guidelines and clinical practice. METHODS: A virtual webinar was held on July 2023 to discuss the state of the art and future perspectives in the treatment of ALK rearrangement in advanced NSCLC in Italy. The faculty hosting the webinar was composed of eight medical oncologists from different regions of Italy with clinical expertise in treating patients with lung cancer. Live-shared notes were used to produce a report to serve as the basis of a review manuscript on the topic. RESULTS: Alectinib and brigatinib are the preferred front-line treatment options in Italy, pending approval of the front-line medicine lorlatinib, which would be considered among the choices. Due to a local regulatory limitation of second-line lorlatinib, which is not allowed after front-line brigatinib, alectinib is commonly the preferred front-line choice to follow a sequence of alectinib, followed by lorlatinib, followed by platinum plus pemetrexed chemotherapy. Age and performance status were not considered per se as clinical features influencing treatment choice. However, treatment compliance is deemed a relevant factor in decision making with regard to the number of pills to be administered. In general, given the availability of alternative choices, the spectrum of patients' comorbidities and polypharmacotherapy interactions should be taken into account in treatment selection according to the toxicity profile of each compound. In addition, several issues were debated with regard to improving treatment outcomes, including testing, brain metastases, and management of an oligoprogressive disease. CONCLUSIONS: The treatment scenario of ALK-positive disease is dynamically evolving. Furthermore, not all FDA- and EMA-approved compounds are approved in Italy with the same indications. This influences therapeutic opportunities and increases the need for greater clinical expertise to help and guide treatment selection.

HERTHENA-Lung01, a Phase II Trial of Patritumab Deruxtecan (HER3-DXd) in Epidermal Growth Factor Receptor-Mutated Non-Small-Cell Lung Cancer After Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitor Therapy and Platinum-Based Chemotherapy.

PURPOSE: Patritumab deruxtecan, or HER3-DXd, is an antibody-drug conjugate consisting of a fully human monoclonal antibody to human epidermal growth factor receptor 3 (HER3) attached to a topoisomerase I inhibitor payload via a stable tetrapeptide-based cleavable linker. We assessed the efficacy and safety of HER3-DXd in patients with epidermal growth factor receptor (EGFR)-mutated non-small-cell lung cancer (NSCLC). METHODS: This phase II study (ClinicalTrials.gov identifier: NCT04619004) was designed to evaluate HER3-DXd in patients with advanced EGFR-mutated NSCLC previously treated with EGFR tyrosine kinase inhibitor (TKI) therapy and platinum-based chemotherapy (PBC). Patients received HER3-DXd 5.6 mg/kg intravenously once every 3 weeks or an uptitration regimen (3.2 → 4.8 → 6.4 mg/kg). The primary end point was confirmed objective response rate (ORR; RECIST 1.1) by blinded independent central review (BICR), with a null hypothesis of 26.4% on the basis of historical data. RESULTS: Enrollment into the uptitration arm closed early on the basis of a prespecified benefit-risk assessment of data from the phase I U31402-A-U102 trial. In total, 225 patients received HER3-DXd 5.6 mg/kg once every 3 weeks. As of May 18, 2023, median study duration was 18.9 (range, 14.9-27.5) months. Confirmed ORR by BICR was 29.8% (95% CI, 23.9 to 36.2); median duration of response, 6.4 months; median progression-free survival, 5.5 months; and median overall survival, 11.9 months. The subgroup of patients with previous osimertinib and PBC had similar outcomes. Efficacy was observed across a broad range of pretreatment tumor HER3 membrane expression levels and across diverse mechanisms of EGFR TKI resistance. In patients with nonirradiated brain metastases at baseline (n = 30), the confirmed CNS ORR by BICR per CNS RECIST was 33.3% (95% CI, 17.3 to 52.8). The safety profile (National Cancer Institute Common Terminology Criteria for Adverse Events v5.0) was manageable and tolerable, consistent with previous observations. CONCLUSION: After tumor progression with EGFR TKI therapy and PBC in patients with EGFR-mutated NSCLC, HER3-DXd once every 3 weeks demonstrated clinically meaningful efficacy with durable responses, including in CNS metastases. A phase III trial in EGFR-mutated NSCLC after progression on an EGFR TKI is ongoing (HERTHENA-Lung02; ClinicalTrials.gov identifier: NCT05338970).

Modern Stereotactic Radiotherapy for Brain Metastases from Lung Cancer: Current Trends and Future Perspectives Based on Integrated Translational Approaches.

Brain metastases (BMs) represent the most frequent metastatic event in the course of lung cancer patients, occurring in approximately 50% of patients with non-small-cell lung cancer (NSCLC) and in up to 70% in patients with small-cell lung cancer (SCLC). Thus far, many advances have been made in the diagnostic and therapeutic procedures, allowing improvements in the prognosis of these patients. The modern approach relies on the integration of several factors, such as accurate histological and molecular profiling, comprehensive assessment of clinical parameters and precise definition of the extent of intracranial and extracranial disease involvement. The combination of these factors is pivotal to guide the multidisciplinary discussion and to offer the most appropriate treatment to these patients based on a personalized approach. Focal radiotherapy (RT), in all its modalities (radiosurgery (SRS), fractionated stereotactic radiotherapy (SRT), adjuvant stereotactic radiotherapy (aSRT)), is the cornerstone of BM management, either alone or in combination with surgery and systemic therapies. We review the modern therapeutic strategies available to treat lung cancer patients with brain involvement. This includes an accurate review of the different technical solutions which can be exploited to provide a "state-of-art" focal RT and also a detailed description of the systemic agents available as effective alternatives to SRS/SRT when a targetable molecular driver is present. In addition to the validated treatment options, we also discuss the future perspective for focal RT, based on emerging clinical reports (e.g., SRS for patients with many BMs from NSCLC or SRS for BMs from SCLC), together with a presentation of innovative and promising findings in translational research and the combination of novel targeted agents with SRS/SRT.

Deciphering Lung Adenocarcinoma Heterogeneity: An Overview of Pathological and Clinical Features of Rare Subtypes.

Lung cancer is one of the most frequently diagnosed cancers worldwide and the leading cause of cancer-related death. The 2021 World Health Organization (WHO) classification provided a detailed and updated categorization of lung adenocarcinomas with a special focus on rare histological types, including enteric, fetal and colloid types, as well as not otherwise specified adenocarcinoma, overall accounting for about 5-10% of all cases. However, rare entities are nowadays difficult to diagnose in most centers, and evidence of optimal therapeutic management for these patients is still lacking. In recent years, increasing knowledge about the mutational profile of lung cancer, in addition to the spreading diffusion of next-generation sequencing (NGS) in different centers, have been helpful in the identification of rare variants of lung cancer. Hence, the hope is that several new drugs will be available in the near future to treat these rare lung tumors, such as in targeted therapy and immunotherapy, which are often used in clinical practice for several malignancies. The aim of this review is to summarize the current knowledge about the molecular pathology and clinical management of the most common rare adenocarcinoma subtypes in order to provide a concise and updated report that can drive clinicians' choices in their routine practice.

The Role of Germline Mutations in Thoracic Malignancies: Between Myth and Reality.

Considering the established contribution of environmental factors to the development of thoracic malignancies, the inherited susceptibility of these tumors has rarely been explored. However, the recent introduction of next-generation sequencing-based tumor molecular profiling in the real-word setting enabled us to deeply characterize the genomic background of patients with lung cancer with or without smoking-related history, increasing the likelihood of detecting germline mutations with potential prevention and treatment implications. Pathogenic germline variants have been detected in 2% to 3% of patients with NSCLC undergoing next-generation sequencing analysis, whereas the proportion of germline mutations associated with the development of pleural mesothelioma widely varies across different studies, ranging between 5% and 10%. This review provides an updated summary of emerging evidence about germline mutations in thoracic malignancies, focusing on pathogenetic mechanisms, clinical features, therapeutic implications, and screening recommendations for high-risk individuals.

Autocrine 17-ß-Estradiol/Estrogen Receptor-α Loop Determines the Response to Immune Checkpoint Inhibitors in Non-Small Cell Lung Cancer.

PURPOSE: The response to immune checkpoint inhibitors (ICI) often differs between genders in non-small cell lung cancer (NSCLC), but metanalyses results are controversial, and no clear mechanisms are defined. We aim at clarifying the molecular circuitries explaining the differential gender-related response to anti-PD-1/anti-PD-L1 agents in NSCLC. EXPERIMENTAL DESIGN: We prospectively analyzed a cohort of patients with NSCLC treated with ICI as a first-line approach, and we identified the molecular mechanisms determining the differential efficacy of ICI in 29 NSCLC cell lines of both genders, recapitulating patients' phenotype. We validated new immunotherapy strategies in mice bearing NSCLC patient-derived xenografts and human reconstituted immune system ("immune-PDXs"). RESULTS: In patients, we found that estrogen receptor α (ERα) was a predictive factor of response to pembrolizumab, stronger than gender and PD-L1 levels, and was directly correlated with PD-L1 expression, particularly in female patients. ERα transcriptionally upregulated CD274/PD-L1 gene, more in females than in males. This axis was activated by 17-ß-estradiol, autocrinely produced by intratumor aromatase, and by the EGFR-downstream effectors Akt and ERK1/2 that activated ERα. The efficacy of pembrolizumab in immune-PDXs was significantly improved by the aromatase inhibitor letrozole, which reduced PD-L1 and increased the percentage of antitumor CD8+T-lymphocytes, NK cells, and Vγ9Vδ2 T-lymphocytes, producing durable control and even tumor regression after continuous administration, with maximal benefit in 17-ß-estradiol/ERα highfemale immune-xenografts. CONCLUSIONS: Our work unveils that 17-ß-estradiol/ERα status predicts the response to pembrolizumab in patients with NSCLC. Second, we propose aromatase inhibitors as new gender-tailored immune-adjuvants in NSCLC. See related commentary by Valencia et al., p. 3832.

Exploring circular MET RNA as a potential biomarker in tumors exhibiting high MET activity.

BACKGROUND: MET-driven acquired resistance is emerging with unanticipated frequency in patients relapsing upon molecular therapy treatments. However, the determination of MET amplification remains challenging using both standard and next-generation sequencing-based methodologies. Liquid biopsy is an effective, non-invasive approach to define cancer genomic profiles, track tumor evolution over time, monitor treatment response and detect molecular resistance in advance. Circular RNAs (circRNAs), a family of RNA molecules that originate from a process of back-splicing, are attracting growing interest as potential novel biomarkers for their stability in body fluids. METHODS: We identified a circRNA encoded by the MET gene (circMET) and exploited blood-derived cell-free RNA (cfRNA) and matched tumor tissues to identify, stratify and monitor advanced cancer patients molecularly characterized by high MET activity, generally associated with genomic amplification. RESULTS: Using publicly available bioinformatic tools, we discovered that the MET locus transcribes several circRNA molecules, but only one candidate, circMET, was particularly abundant. Deeper molecular analysis revealed that circMET levels positively correlated with MET expression and activity, especially in MET-amplified cells. We developed a circMET-detection strategy and, in parallel, we performed standard FISH and IHC analyses in the same specimens to assess whether circMET quantification could identify patients displaying high MET activity. Longitudinal monitoring of circMET levels in the plasma of selected patients revealed the early emergence of MET amplification as a mechanism of acquired resistance to molecular therapies. CONCLUSIONS: We found that measurement of circMET levels allows identification and tracking of patients characterized by high MET activity. Circulating circMET (ccMET) detection and analysis could be a simple, cost-effective, non-invasive approach to better implement patient stratification based on MET expression, as well as to dynamically monitor over time both therapy response and clonal evolution during treatment.

Comutations and KRASG12C Inhibitor Efficacy in Advanced NSCLC.

Molecular modifiers of KRASG12C inhibitor (KRASG12Ci) efficacy in advanced KRASG12C-mutant NSCLC are poorly defined. In a large unbiased clinicogenomic analysis of 424 patients with non-small cell lung cancer (NSCLC), we identified and validated coalterations in KEAP1, SMARCA4, and CDKN2A as major independent determinants of inferior clinical outcomes with KRASG12Ci monotherapy. Collectively, comutations in these three tumor suppressor genes segregated patients into distinct prognostic subgroups and captured ∼50% of those with early disease progression (progression-free survival ≤3 months) with KRASG12Ci. Pathway-level integration of less prevalent coalterations in functionally related genes nominated PI3K/AKT/MTOR pathway and additional baseline RAS gene alterations, including amplifications, as candidate drivers of inferior outcomes with KRASG12Ci, and revealed a possible association between defective DNA damage response/repair and improved KRASG12Ci efficacy. Our findings propose a framework for patient stratification and clinical outcome prediction in KRASG12C-mutant NSCLC that can inform rational selection and appropriate tailoring of emerging combination therapies. SIGNIFICANCE: In this work, we identify co-occurring genomic alterations in KEAP1, SMARCA4, and CDKN2A as independent determinants of poor clinical outcomes with KRASG12Ci monotherapy in advanced NSCLC, and we propose a framework for patient stratification and treatment personalization based on the comutational status of individual tumors. See related commentary by Heng et al., p. 1513. This article is highlighted in the In This Issue feature, p. 1501.

Real-world retrospective study of KRAS mutations in advanced non-small cell lung cancer in the era of immunotherapy.

BACKGROUND: KRAS mutation-positive (KRAS-positive), advanced nonsmall-cell lung cancer (NSCLC) is characterized by a poor prognosis. KRAS mutations are extremely heterogeneous from a biologic point of view, and real-world data by mutation subtype in the era of immunotherapy are still incomplete. METHODS: The objective of this study was to retrospectively analyze all consecutive patients with advanced/metastatic, KRAS-positive NSCLC who were diagnosed at a single academic institution since the advent of immunotherapy. The authors report on the natural history of the disease as well as the efficacy of first-line treatments in the entire cohort and by KRAS mutation subtypes as well as the presence/absence of co-mutations. RESULTS: From March 2016 to December 2021, the authors identified 199 consecutive patients who had KRAS-positive, advanced or metastatic NSCLC. The median overall survival (OS) was 10.7 months (95% confidence interval [CI], 8.5-12.9 months), and there were no differences by mutation subtype. Among 134 patients who received first-line treatment, the median OS was 12.2 months (95% CI, 8.3-16.1 months), and the median progression-free survival was 5.6 months (95% CI, 4.5-6.6 months). At multivariate analysis, only an Eastern Cooperative Oncology Group performance status of 2 was associated with significantly shorter progression-free survival and OS. CONCLUSIONS: KRAS-positive, advanced NSCLC is characterized by a poor prognosis despite the introduction of immunotherapy. Survival was not associated with KRAS mutation subtype. PLAIN LANGUAGE SUMMARY: This study evaluated the efficacy of systemic therapies for advanced/metastatic nonsmall cell lung cancer harboring KRAS mutations, along with the potential predictive and prognostic role of mutation subtypes. The authors found that advanced/metastatic, KRAS-positive nonsmall cell lung cancer is characterized by a poor prognosis and that first-line treatment efficacy is not related to different KRAS mutations, although a numerically shorter median progression-free survival was observed in patients who had p.G12D and p.G12A mutations. These results underline the need for novel treatment options in this population, such as next-generation KRAS inhibitors, which are in clinical and preclinical development.

Tumor plasticity and therapeutic resistance in oncogene-addicted non-small cell lung cancer: from preclinical observations to clinical implications.

The identification of actionable targets in oncogene-addicted non-small cell lung cancer (NSCLC) has fueled biomarker-directed strategies, especially in advanced stage disease. Despite the undeniable success of molecular targeted therapies, duration of clinical response is relatively short-lived. While extraordinary efforts have defined the complexity of tumor architecture and clonal evolution at the genetic level, not equal interest has been given to the dynamic mechanisms of phenotypic adaptation engaged by cancer during treatment. At the clinical level, molecular targeted therapy of EGFR-mutant and ALK-rearranged tumors often results in epithelial-to-mesenchymal transition (EMT) and histological transformation of the original adenocarcinoma without the acquisition of additional genetic lesions, thus limiting subsequent therapeutic options and patient outcome. Here we provide an overview of the current understanding of the genetic and non-genetic molecular circuits governing this phenomenon, presenting current strategies and potentially innovative therapeutic approaches to interfere with lung cancer cell plasticity.