Active thymus in adult with lung cancer: preliminary results from the Adult Thymic Project.

Thymus is considered a non-functional remnant in adults, but some evidence suggest that it may harbor residual activity. Lung cancer patients represent the ideal model to study thymic residual activity, as their thymus can be easily harvested during surgery. This study was designed to confirm the presence of residual thymic activity both in adult mice (step 1) and in humans (step 2). In step 1, lung cancer was induced by activating k-ras mutation in a cohort of 20 young and adult mice. After killing, thymus and lungs were analyzed. Thymus was considered active when medullary was evident, cortico-medullary ratio was 50:50 or higher and adipose involution was present. In step 2, a cohort of 20 patients, undergoing surgery for lung cancer, had biopsy of pericardial fat pad, site of ectopic thymus. Thymus was considered present if Hassall's bodies were detected. In mice, active thymus was detected in a high proportion of cases, without significant difference between adult and young (70% vs 44.4% respectively). Two cases without evidence of lung tumor had a fully functional thymus. In humans, ectopic thymus was detected in the pericardial fat pad in 2 cases (10.5%), confirmed by immunohistochemistry. Signs of previous thymic activity were detected in 8 additional patients. Results confirmed thymus activity in animal models and humans with lung cancer, providing the rationale for future systematic mediastinal thymic biopsy. The comprehension of interactions between thymus, lymphocytes and tumor may open a new potentially targetable perspective in lung cancer.

TFEB controls sensitivity to chemotherapy and immuno-killing in non-small cell lung cancer.

BACKGROUND: In non-small cell lung cancer (NSCLC) the efficacy of chemo-immunotherapy is affected by the high expression of drug efflux transporters as ABCC1 and by the low expression of ABCA1, mediating the isopentenyl pyrophosphate (IPP)-dependent anti-tumor activation of Vγ9Vδ2 T-lymphocytes. In endothelial cells ABCA1 is a predicted target of the transcription factor EB (TFEB), but no data exists on the correlation between TFEB and ABC transporters involved in the chemo-immuno-resistance in NSCLC. METHODS: The impact of TFEB/ABCC1/ABCA1 expression on NSCLC patients' survival was analyzed in the TCGA-LUAD cohort and in a retrospective cohort of our institution. Human NSCLC cells silenced for TFEB (shTFEB) were analyzed for ABC transporter expression, chemosensitivity and immuno-killing. The chemo-immuno-sensitizing effects of nanoparticles encapsulating zoledronic acid (NZ) on shTFEB tumors and on tumor immune-microenvironment were evaluated in Hu-CD34+ mice by single-cell RNA-sequencing. RESULTS: TFEBlowABCA1lowABCC1high and TFEBhighABCA1highABCC1low NSCLC patients had the worst and the best prognosis, respectively, in the TCGA-LUAD cohort and in a retrospective cohort of patients receiving platinum-based chemotherapy or immunotherapy as first-line treatment. By silencing shTFEB in NSCLC cells, we demonstrated that TFEB was a transcriptional inducer of ABCA1 and a repressor of ABCC1. shTFEB cells had also a decreased activity of ERK1/2/SREBP2 axis, implying reduced synthesis and efflux via ABCA1 of cholesterol and its intermediate IPP. Moreover, TFEB silencing reduced cholesterol incorporation in mitochondria: this event increased the efficiency of OXPHOS and the fueling of ABCC1 by mitochondrial ATP. Accordingly, shTFEB cells were less immuno-killed by the Vγ9Vδ2 T-lymphocytes activated by IPP and more resistant to cisplatin. NZ, which increased IPP efflux but not OXPHOS and ATP production, sensitized shTFEB immuno-xenografts, by reducing intratumor proliferation and increasing apoptosis in response to cisplatin, and by increasing the variety of anti-tumor infiltrating cells (Vγ9Vδ2 T-lymphocytes, CD8+T-lymphocytes, NK cells). CONCLUSIONS: This work suggests that TFEB is a gatekeeper of the sensitivity to chemotherapy and immuno-killing in NSCLC, and that the TFEBlowABCA1lowABCC1high phenotype can be predictive of poor response to chemotherapy and immunotherapy. By reshaping both cancer metabolism and tumor immune-microenvironment, zoledronic acid can re-sensitize TFEBlow NSCLCs, highly resistant to chemo- and immunotherapy.

Clinical and Molecular Traits of a Novel SPECC1L-ALK Fusion in a Patient with Advanced Non-Small Cell Lung Cancer.

Anaplastic lymphoma kinase (ALK) fusions account for 5-7% of non-small cell lung cancer (NSCLC) patients, the therapeutic approaches for which have significantly evolved in the last few years. However, the response to target therapies remains heterogeneous, partially due to the many different ALK fusion variants reported to date. Rare fusion variants have also been discovered, but their role in influencing responses to ALK inhibitors (ALKis) remains poorly elucidated. Laboratory investigation at both the tissue and protein levels, and a molecular profile by next-generation sequencing (NGS) were performed on a lung biopsy sample from one patient with poorly differentiated adenocarcinoma. An in silico prediction model using ColabFold software v1.5.5 was used to model and predict the entire structure of the chimeric aberrant ALK protein. Here, we report a case of a former smoker, a 60-year-old man, diagnosed with NSCLC and undergoing ALK translocation. He received first-, second- and third-generation ALK protein inhibitors (ALKis), showing a clinical benefit for about 4 years. IHC analysis and the molecular examination of the tissue biopsy indicated a positive staining for ALK and a novel ALK gene fusion variant, involving the sperm antigen with calponin homology and coiled-coil domain 1-like (SPECC1L) gene with an unreported breakpoint in exon 7. The novel SPECCL1::ALK fusion was identified using Anchored Multiplex PCR (AMP)-NGS technology and was predicted to retain the Pkinase_Tyr domain at the carboxy-terminal region of the resulting chimeric protein. To the best of our knowledge, this is the first case of an ALK-positive NSCLC patient carrying the SPECC1L exon 7 fusion breakpoint and one of the few reports about clinical outcomes related to SPECC1L::ALK fusion. The in silico hypothesized biological role of this newly identified fusion variant corroborates the observed clinical response to multiple ALKis. The molecular findings also reinforce the utility of AMP-based NGS technology as a valuable tool for the identification of rare chromosomal events that may be related to the variability of patient outcomes to different ALKis treatments.

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.

The biomarkers ATLAS: An audit on 1100 non-small cell lung cancer from an Italian knowledge-based database.

AIMS: To date, precision medicine has revolutionized the clinical management of Non-Small Cell Lung Cancer (NSCLC). International societies approved a rapidly improved mandatory testing biomarkers panel for the clinical stratification of NSCLC patients, but harmonized procedures are required to optimize the diagnostic workflow. In this context a knowledge-based database (Biomarkers ATLAS, https://biomarkersatlas.com/) was developed by a supervising group of expert pathologists and thoracic oncologists collecting updated clinical and molecular records from about 80 referral Italian institutions. Here, we audit molecular and clinical data from n = 1100 NSCLC patients collected from January 2019 to December 2020. METHODS: Clinical and molecular records from NSCLC patients were retrospectively collected from the two coordinating institutions (University of Turin and University of Naples). Molecular biomarkers (KRAS, EGFR, BRAF, ROS1, ALK, RET, NTRK, MET) and clinical data (sex, age, histological type, smoker status, PD-L1 expression, therapy) were collected and harmonized. RESULTS: Clinical and molecular data from 1100 (n = 552 mutated and n = 548 wild-type) NSCLC patients were systematized and annotated in the ATLAS knowledge-database. Molecular records from biomarkers testing were matched with main patients' clinical variables. CONCLUSIONS: Biomarkers ATLAS (https://biomarkersatlas.com/) represents a unique, easily managing, and reliable diagnostic tool aiming to integrate clinical records with molecular alterations of NSCLC patients in the real-word Italian scenario.

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.

Pulmonary Low Malignant Potential Adenocarcinoma: A Validation of the Proposed Criteria for This Novel Subtype.

Adenocarcinoma (ADC) is the most common histologic type of lung cancer, including in situ (lepidic), minimally invasive, and invasive forms. While the former 2 types are associated with a favorable outcome, the latter includes tumors with variable behavior, often tumor stage-related. A recent study proposed strict morphologic criteria defining a new subgroup of resected stage I invasive ADC (16% of cases) with favorable outcomes (100% disease-specific survival), named "ADC of low malignant potential (LMP-ADC)." The following criteria were met: ≤3 cm size, nonmucinous histotype, ≥15% lepidic growth, and the absence of the following: high-grade patterns, >1 mitosis/2 mm 2 , necrosis, and vascular/pleural invasion. The aim of the present study was to validate the performance of such criteria to identify LMP-ADC in a series of 274 stage IA resected lung ADCs from a single institution. Thirty-four tumors (12.4%) met the proposed criteria for LMP-ADC, as confirmed by additional stains for mitotic figures, Ki67 index, and elastic fibers (helpful to assess alveolar wall invasion). Minor differences between the lepidic and invasive components were observed regarding cell atypia and proliferation. p53 was normally expressed by invasive tumor cells. Mutations occurred in known lung cancer genes (mostly KRAS and EGFR). Five patients (14.7%) developed disease progression and 2 of them (5.9%) died of the disease. In our series, the disease-specific survival was 94.1%. In conclusion, in resected invasive lung ADC, a subgroup presenting low-grade morphologic features and associated with favorable prognosis does exist. Morphologic criteria for LMP-ADC supported by ancillary techniques represent a valid tool to better define this novel subgroup and to refine the stratification of invasive lung ADC, possibly suggesting modified follow-up protocols, based on the observed indolent behavior in most cases.

Updates on lung neuroendocrine neoplasm classification.

Lung neuroendocrine neoplasms (NENs) are a heterogeneous group of pulmonary neoplasms showing different morphological patterns and clinical and biological characteristics. The World Health Organisation (WHO) classification of lung NENs has been recently updated as part of the broader attempt to uniform the classification of NENs. This much-needed update has come at a time when insights from seminal molecular characterisation studies revolutionised our understanding of the biological and pathological architecture of lung NENs, paving the way for the development of novel diagnostic techniques, prognostic factors and therapeutic approaches. In this challenging and rapidly evolving landscape, the relevance of the 2021 WHO classification has been recently questioned, particularly in terms of its morphology-orientated approach and its prognostic implications. Here, we provide a state-of-the-art review on the contemporary understanding of pulmonary NEN morphology and the potential contribution of artificial intelligence, the advances in NEN molecular profiling with their impact on the classification system and, finally, the key current and upcoming prognostic factors.

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.

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.

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.

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.

Genetic Ablation of the MET Oncogene Defines a Crucial Role of the HGF/MET Axis in Cell-Autonomous Functions Driving Tumor Dissemination.

Cancer cell dissemination is sustained by cell-autonomous and non-cell-autonomous functions. To disentangle the role of HGF (Hepatocyte Growth Factor) and MET ligand/receptor axis in this complex process, we genetically knocked out the MET gene in cancer cells in which MET is not the oncogenic driver. In this way, we evaluated the contribution of the HGF/MET axis to cancer cell dissemination independently of its direct activities in cells of the tumor microenvironment. The lack of MET expression in MET-/- cells has been proved by molecular characterization. From a functional point of view, HGF stimulation of MET-/- cancer cells was ineffective in eliciting intracellular signaling and in sustaining biological functions predictive of malignancy in vitro (i.e., anchorage-independent growth, invasion, and survival in the absence of matrix adhesion). Cancer cell dissemination was assessed in vivo, evaluating: (i) the ability of MET-/- lung carcinoma cells to colonize the lungs following intravenous injection and (ii) the spontaneous dissemination to distant organs of MET-/- pancreatic carcinoma cells upon orthotopic injection. In both experimental models, MET ablation affects the time of onset, the number, and the size of metastatic lesions. These results define a crucial contribution of the HGF/MET axis to cell-autonomous functions driving the metastatic process.

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.

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.

Unprecedented long-term survival in a patient with malignant pleural mesothelioma treated with subsequent systemic chemo- and immunotherapeutic regimens.

Pleural mesothelioma is a rare disease with a dismal prognosis and few therapeutic options. Until recently the median overall survival for a pleural mesothelioma patient was up to 2 years, with few exceptional cases of patients achieving a longer survival. Here, we report the clinical case of a patient whose survival spanned over 10 years. The patient underwent several systemic treatments, including three different chemotherapy lines (cisplatin-pemetrexed, vinorelbine and platinum rechallenge) and two immunotherapy regimens using immune checkpoint inhibitors (anti CTLA-4 tremelimumab and anti PD-1 nivolumab). At the time this report was written, the patient was off-treatment, asymptomatic and with a stable radiological disease. Our case demonstrates that a prolonged survival with a preserved quality of life may be reached in selected patients through the exploitation of the available treatments in an expertise setting.

Novel Lymphocyte-Independent Antitumor Activity by PD-1 Blocking Antibody against PD-1+ Chemoresistant Lung Cancer Cells.

PURPOSE: Antibodies against the lymphocyte PD-1 (aPD-1) receptor are cornerstone agents for advanced non-small cell lung cancer (NSCLC), based on their ability to restore the exhausted antitumor immune response. Our study reports a novel, lymphocyte-independent, therapeutic activity of aPD-1 against NSCLC, blocking the tumor-intrinsic PD-1 receptors on chemoresistant cells. EXPERIMENTAL DESIGN: PD-1 in NSCLC cells was explored in vitro at baseline, including stem-like pneumospheres, and following treatment with cisplatin both at transcriptional and protein levels. PD-1 signaling and RNA sequencing were assessed. The lymphocyte-independent antitumor activity of aPD-1 was explored in vitro, by PD-1 blockade and stimulation with soluble ligand (PD-L1s), and in vivo within NSCLC xenograft models. RESULTS: We showed the existence of PD-1+ NSCLC cell subsets in cell lines and large in silico datasets (Cancer Cell Line Encyclopedia and The Cancer Genome Atlas). Cisplatin significantly increased PD-1 expression on chemo-surviving NSCLC cells (2.5-fold P = 0.0014), while the sequential treatment with anti-PD-1 Ab impaired their recovery after chemotherapy. PD-1 was found to be associated with tumor stemness features. PD-1 expression was enhanced in NSCLC stem-like pneumospheres (P < 0.0001), significantly promoted by stimulation with soluble PD-L1 (+27% ± 4, P < 0.0001) and inhibited by PD-1 blockade (-30% ± 3, P < 0.0001). The intravenous monotherapy with anti-PD-1 significantly inhibited tumor growth of NSCLC xenografts in immunodeficient mice, without the contribution of the immune system, and delayed the occurrence of chemoresistance when combined with cisplatin. CONCLUSIONS: We report first evidence of a novel lymphocyte-independent activity of anti-PD-1 antibodies in NSCLC, capable of inhibiting chemo-surviving NSCLC cells and exploitable to contrast disease relapses following chemotherapy. See related commentary by Augustin et al., p. 505.

Comparing T Cell Subsets in Broncho-Alveolar Lavage (BAL) and Peripheral Blood in Patients with Advanced Lung Cancer.

BACKGROUND: Lung cancer (LC) tissue for immunological characterization is often scarce. We explored and compared T cell characteristics between broncho-alveolar lavage from tumor affected (t-BAL) and contralateral lung (cl-BAL), with matched peripheral blood (PB). METHODS: BAL and PB were collected during bronchoscopy for diagnostic and/or therapeutic purposes in patients with monolateral primary lesion. RESULTS: Of 33 patients undergoing BAL and PB sampling, 21 had histologically-confirmed LC. Most cases were locally-advanced or metastatic non-small cell LC. T cell characteristics were not significantly different in t-BAL vs. cl-BAL. Compared to PB, CD8 T cells in BAL presented features of immune activation and exhaustion (high PD-1, low IFN-g production). Accordingly, regulatory CD4 T cells were also higher in BAL vs. PB. When dichotomizing T cell density in t-BAL in high and low, we found that PD-L1 expression in LC was associated with T cell density in t-BAL. T-BAL with high T cell density had higher %IFN-g+CD8 T cells and lower %T-regs. CONCLUSION: In BAL from advanced LC patients, T cells present features of exhaustion. T cells in t-BAL could be the best surrogate of tumor-infiltrating T cell, and future studies should evaluate T cell phenotype and density as potential biomarkers for cancer immunotherapy outcome.

Immunohistochemistry with 3 different clones in anaplastic lymphoma kinase fluorescence in situ hybridization positive non-small-cell lung cancer with thymidylate synthase expression analysis: a multicentre, retrospective, Italian study.

Introduction: ALK rearrangement is the only druggable oncogenic driver detectable by immunohistochemistry (IHC) not requiring further confirmation of positivity in accessing first-line specific inhibitors. ALK-positive patients experience clinical benefit from pemetrexed-based chemotherapy possibly due to lower thymidylate synthase (TS) levels. This study assesses agreement with three different ALK IHC clones in 37 FISH-positive NSCLC. TS expression by real time (RT)-PCR was compared with ALK FISH-negative cases. Materials and methods: 37 ALK FISH-positive NSCLC cases diagnosed between 2010 and 2015 in 7 Italian centres were investigated with ICH using three different anti-ALK antibodies (ALK1, 5A4 and D5F3). Staining for ALK1 and 5A4 was graded as 0+,1+,2+, and 3+, while the scoring for D5F3 was recorded as negative or positive. Proportion agreement analysis was done using Cohen's unweighted kappa (k). TS and ß-actin expression levels were analysed by quantitative RT-PCR. Comparison between TS expression in ALK FISH-positive specimens and a control cohort of ALK FISH-negative ones was performed with the Mann-Whitney and Kruskal-Wallis tests. Results: Considering 2+ and 3+ as positive, the proportion of IHC agreement was 0.1691 (95% CI 0-0.4595) for ALK1/5A4, 0.1691 (95% CI 0-0.4595) for ALK1/D5F3, and 1 for D5F3/5A4. Considering 3+ as positive, it was 0.1543 (95% CI 0-0.4665) for ALK1/ 5A4, 0.0212 (95% CI 0-0.1736) for ALK1/D5F3, and 0.2269 (95% CI 0-0.5462) for 5A4/D5F3. Median TS expression was 6.07 (1.28-14.94) and ALK-positive cases had a significant lower TS expression than ALK-negative tumours (p = 0.002). Conclusions: IHC proved to be a reliable tool for the diagnosis of ALK-rearranged NSCLC. D5F3 and 5A4 clones have the highest percentage of agreement. TS levels are significantly lower in FISH-positive patients.