Micronodular thymic epithelial tumors with lymphoid hyperplasia and mimicking lesions.

Micronodular arrangement of epithelial cells and lymphoid B-cell hyperplasia with follicles are both peculiar histological features in thymic tissue. Such features may especially occur in thymic epithelial tumors. The most common form is called micronodular thymoma with lymphoid stroma. We have recently described some characteristics of thymic micronodular carcinoma with lymphoid hyperplasia, highlighting how this carcinomatous counterpart should not be misdiagnosed as a thymoma. In this review, we discuss these two entities but also other mimics, which may occur in the anterior mediastinum. These mimics include various types of cellular micronodules and lymphoid backgrounds encompassing a wide range of mediastinal lesions. Non-neoplastic lesions, such as thymic nodular epithelial hyperplasia, thymic lymphoid hyperplasia, or sarcoidosis, as well as tumors of very varying aggressiveness, such as micronodular thymic epithelial tumors, low-grade lymphoma, seminoma, or lymphoepithelial carcinoma, are discussed. We show how these lesions may be misleading and we describe how a correct diagnostic may be obtained in current practice.

WhARIO: whole-slide-image-based survival analysis for patients treated with immunotherapy.

Purpose: Immune checkpoint inhibitors (ICIs) are now one of the standards of care for patients with lung cancer and have greatly improved both progression-free and overall survival, although <20% of the patients respond to the treatment, and some face acute adverse events. Although a few predictive biomarkers have integrated the clinical workflow, they require additional modalities on top of whole-slide images and lack efficiency or robustness. In this work, we propose a biomarker of immunotherapy outcome derived solely from the analysis of histology slides. Approach: We develop a three-step framework, combining contrastive learning and nonparametric clustering to distinguish tissue patterns within the slides, before exploiting the adjacencies of previously defined regions to derive features and train a proportional hazards model for survival analysis. We test our approach on an in-house dataset of 193 patients from 5 medical centers and compare it with the gold standard tumor proportion score (TPS) biomarker. Results: On a fivefold cross-validation (CV) of the entire dataset, the whole-slide image-based survival analysis for patients treated with immunotherapy (WhARIO) features are able to separate a low- and a high-risk group of patients with a hazard ratio (HR) of 2.29 (CI95=1.48 to 3.56), whereas the TPS 1% reference threshold only reaches a HR of 1.81 (CI95=1.21 to 2.69). Combining the two yields a higher HR of 2.60 (CI95=1.72 to 3.94). Additional experiments on the same dataset, where one out of five centers is excluded from the CV and used as a test set, confirm these trends. Conclusions: Our uniquely designed WhARIO features are an efficient predictor of survival for lung cancer patients who received ICI treatment. We achieve similar performance to the current gold standard biomarker, without the need to access other imaging modalities, and show that both can be used together to reach even better results.

An unusual case of primary splenic soft part alveolar sarcoma: case report and review of the literature with emphasis on the spectrum of TFE3-associated neoplasms.

BACKGROUND: Alveolar soft part sarcoma is a rare tumour of soft tissues, mostly localized in muscles or deep soft tissues of the extremities. In rare occasions, this tumour develops in deep tissues of the abdomen or pelvis. CASE PRESENTATION: In this case report, we described the case of a 46 year old man who developed a primary splenic alveolar soft part sarcoma. The tumour displayed typical morphological alveolar aspect, as well as immunohistochemical profile notably TFE3 nuclear staining. Detection of ASPSCR1 Exon 7::TFE3 Exon 6 fusion transcript in molecular biology and TFE3 rearrangement in FISH confirmed the diagnosis. CONCLUSION: We described the first case of primary splenic alveolar soft part sarcoma, which questions once again the cell of origin of this rare tumour.

Detection of Tumor DNA in Bronchoscopic Fluids in Peripheral NSCLC: A Proof-of-Concept Study.

Introduction: DNA genotyping from plasma is a useful tool for molecular characterization of NSCLC. Nevertheless, the false-negative rate justifies the development of methods with higher sensitivity, especially in difficult-to-reach peripheral lung tumors. Methods: We aimed at comparing molecular analysis from the supernatant of guide sheath flush fluid collected during radial-EndoBronchial UltraSound (r-EBUS) bronchoscopy with plasma sampling and tumor biopsies in patients with peripheral NSCLC. The DNA was genotyped using high-throughput sequencing or the COBAS mutation test. There were 65 patients with peripheral lung tumors subjected to concomitant sampling of guide sheath flush supernatant, plasma tumor DNA, and tumor biopsy and cytology using r-EBUS. There were 33 patients (including 24 newly diagnosed with having NSCLC) with an identifiable tumor mutation in the primary lesion selected for the comparative analysis. Results: Guide sheath flush-based genotyping yielded a mutation detection rate of 61.8% (17 of 24 mutated EGFR, one of two ERBB2, one of one KRAS, one of one MAP2K, one of four MET, and zero of one STK11), compared with 33% in plasma-based genotyping (p = 0.0151). Furthermore, in eight of 34 r-EBUS without tumor cells on microscopic examination, we were able to detect the mutation in four paired guide sheath flush supernatant, compared with only two in paired plasma. Conclusion: The detection of tumor DNA in the supernatant of guide sheath flush fluid collected during r-EBUS bronchoscopy represents a sensitive and complementary method for genotyping NSCLC.

Squamous Cell Carcinoma of the Lung With Microsatellite Instability in a Patient With Lynch Syndrome: A Case Report.

Lynch syndrome is the most common autosomal dominant inherited cancer predisposing syndrome, due to mutations in DNA mismatch repair genes. The key feature of cancers in Lynch syndrome is microsatellite instability and a high risk of developing mainly colorectal and uterine cancers. However, cancers with microsatellite instability outside this spectrum, for example, lung cancer, are extremely rare. Here, we report a case of squamous cell carcinoma of the lung with microsatellite instability in a patient with Lynch syndrome.

Beyond the Frontline: A Triple-Line Approach of Thoracic Surgeons in Lung Cancer Management-State of the Art.

Non-small cell lung cancer (NSCLC) is now described as an extremely heterogeneous disease in its clinical presentation, histology, molecular characteristics, and patient conditions. Over the past 20 years, the management of lung cancer has evolved with positive results. Immune checkpoint inhibitors have revolutionized the treatment landscape for NSCLC in both metastatic and locally advanced stages. The identification of molecular alterations in NSCLC has also allowed the development of targeted therapies, which provide better outcomes than chemotherapy in selected patients. However, patients usually develop acquired resistance to these treatments. On the other hand, thoracic surgery has progressed thanks to minimally invasive procedures, pre-habilitation and enhanced recovery after surgery. Moreover, within thoracic surgery, precision surgery considers the patient and his/her disease in their entirety to offer the best oncologic strategy. Surgeons support patients from pre-operative rehabilitation to surgery and beyond. They are involved in post-treatment follow-up and lung cancer recurrence. When conventional therapies are no longer effective, salvage surgery can be performed on selected patients.

Assessment of endobronchial ultrasound-guided bronchoscopy (EBUS) intranodal forceps biopsy added to EBUS 19-gauge transbronchial needle aspiration: A blinded pathology panel analysis.

BACKGROUND: Endobronchial ultrasound-guided (EBUS) transbronchial needle aspiration (TBNA) has significantly improved the diagnostic workup for intrathoracic lymphadenopathies. More recently, EBUS intranodal forceps biopsy (IFB) has been developed in an attempt to maximize diagnostic yield by providing additional tissue. In this study, we aimed to assess the improvement of diagnostic yield with EBUS-TBNA combined with EBUS-IFB, compared to EBUS-TBNA alone. METHODS: Consecutive patients who had 19-G EBUS-TBNA and EBUS-IFB from August 30, 2018, to September 28, 2021, were included. Four senior pathologists retrospectively analyzed, independently and blindly, first, only the EBUS-TBNA samples (cell block), then, at least 1 month later, both samples from EBUS-TBNA and from EBUS-IFB together. RESULTS: Fifty patients were included in the study and 52 lymph nodes were analyzed. Diagnostic yield was 77% (40/52) for EBUS-TBNA alone and 94% (49/52) when combined with EBUS-IFB (p = 0.023). Malignancy was diagnosed with EBUS-TBNA combined with EBUS-IFB in 25/26 cases (96%), versus 22/26 (85%) with EBUS-TBNA alone (p = 0.35); and 4/5 (80%) versus 2/5 (40%) for lymphoma specifically. Kappa interobserver agreement was 0.92 for EBUS-IFB and 0.87 for EBUS-TBNA alone. Nonmalignant condition was diagnosed with EBUS-TBNA combined with EBUS-IFB in 24/26 cases (92%), versus 18/26 (69%) for EBUS-TBNA alone (p = 0.07). CONCLUSION: The use of EBUS-IFB combined with 19-G EBUS-TBNA improves the mediastinal lymph node diagnostic yield However the benefit appears to be mainly restricted to nonmalignant histology.

Ultrafast Gene Fusion Assessment for Nonsquamous NSCLC.

Introduction: Gene fusion testing of ALK, ROS1, RET, NTRK, and MET exon 14 skipping mutations is guideline recommended in nonsquamous NSCLC (NS-NSCLC). Nevertheless, assessment is often hindered by the limited availability of tissue and prolonged next-generation sequencing (NGS) testing, which can protract the initiation of a targeted therapy. Therefore, the development of faster gene fusion assessment is critical for optimal clinical decision-making. Here, we compared two ultrafast gene fusion assays (UFGFAs) using NGS (Genexus, Oncomine Precision Assay, Thermo Fisher Scientific) and a multiplex reverse-transcriptase polymerase chain reaction (Idylla, GeneFusion Assay, Biocartis) approach at diagnosis in a retrospective series of 195 NS-NSCLC cases and five extrapulmonary tumors with a known NTRK fusion. Methods: A total of 195 NS-NSCLC cases (113 known gene fusions and 82 wild-type tumors) were included retrospectively. To validate the detection of a NTRK fusion, we added five NTRK-positive extrathoracic tumors. The diagnostic performance of the two UFGFAs and standard procedures was compared. Results: The accuracy was 92.3% and 93.1% for Idylla and Genexus, respectively. Both systems improved the sensitivity for detection by including a 5'-3' imbalance analysis. Although detection of ROS1, MET exon 14 skipping, and RET was excellent with both systems, ALK fusion detection was reduced with sensitivities of 87% and 88%, respectively. Idylla had a limited sensitivity of 67% for NTRK fusions, in which only an imbalance assessment was used. Conclusions: UFGFA using NGS and reverse-transcriptase polymerase chain reaction approaches had an equal level of detection of gene fusion but with some technique-specific limitations. Nevertheless, UFGFA detection in routine clinical care is feasible with both systems allowing faster initiation of therapy and a broad degree of screening.

Radial-EBUS and virtual bronchoscopy planner for peripheral lung cancer diagnosis: How it became the first-line endoscopic procedure.

BACKGROUND: Various advanced bronchoscopy methods have been developed to reach peripheral lung lesions (PLL). In a large cohort, we aimed to assess a standardized procedure of first-line radial-endobronchial ultrasound (r-EBUS) and virtual bronchoscopy planner for the diagnosis of peripheral lung cancer. METHODS: This retrospective, single center study included patients who had r-EBUS-guided bronchoscopy for the diagnosis of a PLL between 2008 and 2019. Cases without a final diagnosis of cancer or follow-up were excluded. RESULTS: Between 2008 and 2019, 2735 patients had a r-EBUS procedure, among whom 1627 had a final diagnosis of cancer and were included in the present study. Over the 12-year study period, r-EBUS became the first-line endoscopic procedure to assess PLL (25% as first-line bronchoscopy in 2008 vs. 92% in 2019). The frequency of the bronchus sign decreased from 2009 to 2019 (100% to 80%; p = 0.001), whereas US visualization of the lesion remained stable (88%). The median number of biopsies increased from two (2008 to 2014) to four (2015 to 2019) (p < 0.0001), with the same diagnostic efficiency (74% total and 80% when a bronchus sign was present). Of the 651 adenocarcinomas, molecular analysis was possible in 86%. PD-L1 expression analysis was possible in 81% of cases. During the study period, the lifetime of the radial probe increased from 57 procedures to 77 procedures/probe. CONCLUSION: Because r-EBUS and VB planner is easy to perform under local anesthesia, inexpensive and efficient it can be used as a first-line procedure to assess peripheral lung cancer.

Priming of Cardiopulmonary Bypass with Human Albumin Decreases Endothelial Dysfunction after Pulmonary Ischemia-Reperfusion in an Animal Model.

The routine use of mechanical circulatory support during lung transplantation (LTx) is still controversial. The use of prophylactic human albumin (HA) or hypertonic sodium lactate (HSL) prime in mechanical circulatory support during LTx could prevent ischemia−reperfusion (IR) injuries and pulmonary endothelial dysfunction and thus prevent the development of pulmonary graft dysfunction. The objective was to investigate the impact of cardiopulmonary bypass (CPB) priming with HA and HSL compared to a CPB prime with Gelofusine (GF) on pulmonary endothelial dysfunction in a lung IR rat model. Rats were assigned to four groups: IR-CPB-GF group, IR-CPB-HA group, IR-CPB-HSL group and a sham group. The study of pulmonary vascular reactivity by wire myograph was the primary outcome. Glycocalyx degradation (syndecan-1 and heparan) was also assessed by ELISA and electron microscopy, systemic and pulmonary inflammation by ELISA (IL-1ß, IL-10, and TNF-α) and immunohistochemistry. Clinical parameters were evaluated. We employed a CPB model with three different primings, permitting femoral−femoral assistance with left pulmonary hilum ischemia for IR. Pulmonary endothelium-dependent relaxation to acetylcholine was significantly decreased in the IR-CPB-GF group (11.9 ± 6.2%) compared to the IR-CPB-HA group (52.8 ± 5.2%, p < 0.0001), the IR-CPB-HSL group (57.7 ± 6.3%, p < 0.0001) and the sham group (80.8 ± 6.5%, p < 0.0001). We did not observe any difference between the groups concerning glycocalyx degradation, and systemic or tissular inflammation. The IR-CPB-HSL group needed more vascular filling and developed significantly more pulmonary edema than the IR-CPB-GF group and the IR-CPB-HA group. Using HA as a prime in CPB during Ltx could decrease pulmonary endothelial dysfunction's IR-mediated effects. No effects of HA were found on inflammation.

Endoscopic follow-up of low-grade precancerous bronchial lesions in high-risk patients: long-term results of the SELEPREBB randomised multicentre trial.

BACKGROUND: 3-9% of low-grade preinvasive bronchial lesions progress to cancer. This study assessed the usefulness of an intensive bronchoscopy surveillance strategy in patients with bronchial lesions up to moderate squamous dysplasia. METHODS: SELEPREBB (ClinicalTrials.gov NCT00213603) was a randomised study conducted in 17 French centres. After baseline lung computed tomography (CT) and autofluorescence bronchoscopy (AFB) to exclude lung cancer and bronchial severe squamous dysplasia or carcinoma in situ (CIS), patients were assigned to standard surveillance (arm A) with CT and AFB at 36 months or to intensive surveillance (arm B) with AFB every 6 months. Further long-term data were obtained with a median follow-up of 4.7 years. RESULTS: 364 patients were randomised (A: 180, B: 184). 27 patients developed invasive lung cancer and two developed persistent CIS during the study, with no difference between arms (OR 0.63, 95% CI 0.20-1.96, p=0.42). Mild or moderate dysplasia at baseline bronchoscopy was a significant lung cancer risk factor both at 3 years (8 of 74 patients, OR 6.9, 95% CI 2.5-18.9, p<0.001) and at maximum follow-up (16 of 74 patients, OR 5.9, 95% CI 2.9-12.0, p<0.001). Smoking cessation was significantly associated with clearance of bronchial dysplasia on follow-up (OR 0.12, 95% CI 0.01-0.66, p=0.005) and with a reduced risk of lung cancer at 5 years (OR 0.15, 95% CI 0.003-0.99, p=0.04). CONCLUSION: Patients with mild or moderate dysplasia are at very high risk for lung cancer at 5 years, with smoking cessation significantly reducing the risk. Whereas intensive bronchoscopy surveillance does not improve patient outcomes, the identification of bronchial dysplasia using initial bronchoscopy maybe useful for risk stratification strategies in lung cancer screening programmes.

Morphological and Molecular Characterization of KRAS G12C-Mutated Lung Adenocarcinomas.

Lung adenocarcinoma (LUAD) is the major subtype of non-small cell lung cancer, accounting for approximately 60% of cases. Molecular analysis of LUADs showed that the KRAS gene is mutated in up to 30% of cases; such cases were previously considered "undruggable". The KRAS G12C mutation has become a hot topic of research after initial, promising, phase I and II trials with targeted inhibitors. We analyzed the morphological and genomic landscape of 202 KRAS G12C mutated LUADs using next-generation sequencing, and identified a specific subtype of patients that could show an improved response to KRAS G12C inhibitors. The main histological subtype was acinar in 29.7% of cases. Tumor-infiltrating lymphocytes (TILs) were highly or moderately abundant in more than 60% of cases. The immunohistochemical profile showed TTF1 positivity in 78.7% of cases and PD-L1 positivity in 44.1% of cases. The molecular profile showed an association between KRAS G12C and STK11 mutations in 25.2% of cases. This subgroup was associated with a statistically significant lower TTF1 (p = 0.0092) and PD-L1 (p < 0.0001) positivity. This type of combined morphological and molecular analysis can improve our understanding of tumor biology, and help us to identify specific patient subgroups that can achieve the best treatment response.

Lung Cancer Surgery after Treatment with Anti-PD1/PD-L1 Immunotherapy for Non-Small-Cell Lung Cancer: A Case-Cohort Study.

BACKGROUND: Immune checkpoint inhibitors (ICIs) are the standard of care for non-resectable non-small-cell lung cancer and are under investigation for resectable disease. Some authors have reported difficulties during lung surgery following ICI treatment. This retrospective study investigated the perioperative outcomes of lung resection in patients with preoperative ICI. METHODS: Patients with major lung resection after receiving ICIs were included as cases and were compared to patients who received preoperative chemotherapy without ICI. Surgical, clinical, and imaging data were collected. RESULTS: A total of 25 patients were included in the ICI group, and 34 were included in the control group. The ICI patients received five (2-18) infusions of ICI (80% with pembrolizumab). Indications for surgery varied widely across groups (p < 0.01). Major pathological response was achieved in 44% of ICI patients and 23.5% of the control group (p = 0.049). Surgery reports showed a higher rate of tissue fibrosis/inflammation in the ICI group (p < 0.01), mostly in centrally located tumours (7/13, 53.8% vs. 3/11, 27.3% of distal tumours, p = 0.24), with no difference in operating time (p = 0.81) nor more conversions (p = 0.46) or perioperative complications (p = 0.94). There was no 90-day mortality. Disease-free survival was higher in the ICI group (HR = 0.30 (0.13-0.71), p = 0.02). CONCLUSIONS: This study further supports the safety and feasibility of lung resection in patients following preoperative treatment with ICI.

[RNAseq in routine oncology]. / Le RNAseq en oncologie de routine.

High throughput RNA sequencing, also know as RNAseq, can easily be performed on the gold-standard technique of formalin-fixed paraffin-embedded tissue, which has long been successfully used in routine practice by pathologists. For this reason, RNAseq has been fully adopted in a very short period of time in most French molecular platforms of cancer genotyping, generating "high throughput" data, both qualitative (mutations, fusions) and quantitative (gene expression profiles). This technique opens new perspectives in oncology practice: from a diagnostic point of view (some gene fusions are specific of some diagnoses, some transcriptomic signatures suggest some types of cancer), but also from a prognostic point of view (gene expression profile of an aggressive tumor, or conversely of an indolent one), and above all from a predictive point of view, guiding the choice of potential targeted therapies (example of ALK, ROS1 or NTRK translocations). This technical approach has many advantages, first and foremost it detects, at one go, a plethora of molecular alterations which were previously analyzed sequentially using heterogenous assays (immunohistochemistry, DNA genotyping, fluorescent in situ hybridization, etc.). However, it also presents several drawbacks which may easily be overcome if certain pre-analytic parameters are correctly controlled, mainly aiming at the preservation of the quality of nucleic acids. In any event, the widespread use of RNAseq has had a profound impact on the algorithms of tumor tissue processing, shaping a new, holistic era in oncology.

First Comparison between [18f]-FMISO and [18f]-Faza for Preoperative Pet Imaging of Hypoxia in Lung Cancer.

Hypoxic areas are typically resistant to treatment. However, the fluorine-18-fluoroazomycin-arabinoside (FAZA) and fluorine 18 misonidazole (FMISO) tracers have never been compared in non small cell lung cancer (NSCLC). This study compares the capability of 18F-FAZA PET/CT with that of 18F-FMISO PET/CT for detecting hypoxic tumour regions in early and locally advanced NSCLC patients. We prospectively evaluated patients who underwent preoperative PET scans before surgery for localised NSCLC (i.e., fluorodeoxyglucose (FDG)-PET, FMISO-PET, and FAZA-PET). The PET data of the three tracers were compared with each other and then compared to immunohistochemical analysis (GLUT-1, CAIX, LDH-5, and HIF1-Alpha) after tumour resection. Overall, 19 patients with a mean age of 68.2 ± 8 years were included. There were 18 lesions with significant uptake (i.e., SUVmax >1.4) for the F-MISO and 17 for FAZA. The mean SUVmax was 3 (±1.4) with a mean volume of 25.8 cc (±25.8) for FMISO and 2.2 (±0.7) with a mean volume of 13.06 cc (±13.76) for FAZA. The SUVmax of F-MISO was greater than that of FAZA (p = 0.0003). The SUVmax of F-MISO shows a good correlation with that of FAZA at 0.86 (0.66-0.94). Immunohistochemical results are not correlated to hypoxia PET regardless of the staining. The two tracers show a good correlation with hypoxia, with FMISO being superior to FAZA. FMISO, therefore, remains the reference tracer for defining hypoxic volumes.

Anti-PD1/PD-L1 Immunotherapy for Non-Small Cell Lung Cancer with Actionable Oncogenic Driver Mutations.

Anti-PD1/PD-L1 immunotherapy has emerged as a standard of care for stage III-IV non-small cell lung cancer (NSCLC) over the past decade. Patient selection is usually based on PD-L1 expression by tumor cells and/or tumor mutational burden. However, mutations in oncogenic drivers such as EGFR, ALK, BRAF, or MET modify the immune tumor microenvironment and may promote anti-PD1/PD-L1 resistance. In this review, we discuss the molecular mechanisms associated with these mutations, which shape the immune tumor microenvironment and may impede anti-PD1/PD-L1 efficacy. We provide an overview of the current clinical data on anti-PD1/PD-L1 efficacy in NSCLC with oncogenic driver mutation.

Micronodular thymic carcinoma with lymphoid hyperplasia: relevance of immunohistochemistry with a small panel of antibodies for diagnosis-a RYTHMIC study.

Micronodular thymic carcinoma with lymphoid hyperplasia (MNTCLH) is a rare form of thymic carcinoma. We present the experience of RYTHMIC, the French national network devoted to the treatment of thymic epithelial tumors through multidisciplinary tumor boards with a review of all tumors by pathologists for classification and staging. Six cases of MNTCLH were diagnosed during a review of 1007 thymic epithelial tumors. Histologically, epithelial cells with atypia and mitoses formed micronodules that were surrounded by an abundant lymphoid background with follicles. There was neither obvious fibro-inflammatory stroma nor necrosis. Spindle cells areas were common. Initial diagnosis was micronodular thymoma in two cases, cellular atypia being overlooked, eclipsed by the micronodular pattern. Immunohistochemistry with a panel of five antibodies showed that cytokeratins (AE1-AE3) and p63-positive epithelial cells also expressed CD5 and that there was no TdT-positive cells within the tumors. CD20 highlighted the lymphoid hyperplasia. Additionally epithelial cells also expressed CD117 and diffusely Glut 1. Twenty-seven micronodular thymomas with lymphoid stroma diagnosed during the same period did not show the CD5 and CD117 positivities seen in MNTCLH and contained TdT-positive lymphocytes. Three of the 6 patients with MNTCLH had adjuvant radiotherapy. Three patients with follow-up information were alive without recurrence at 38, 51, and 95 months. Our study shows that immunohistochemistry, such as that used in the RYTHMIC network with a small panel of antibodies, may easily help to confirm the correct diagnosis of MNTCLH, a rare and low-aggressive form of thymic carcinoma, and avoid the misdiagnosis of micronodular thymoma.

An improved assay for detection of theranostic gene translocations and MET exon 14 skipping in thoracic oncology.

Theranostic translocations may be difficult to detect by routine techniques, especially when specimens are exiguous. We recently demonstrated in a series of translocated lung adenocarcinomas that LD-RT-PCR (ligation-dependent reverse transcription polymerase chain reaction) assay could identify ALK, ROS1 and RET rearrangements with 64% sensitivity and 100% specificity. Here, we report an upgraded version of this assay used in a routine prospective cohort of lung carcinomas. Newly diagnosed lung carcinomas referred to the Rouen molecular platform between 15/05/2018 and 15/05/2019 for ALK and ROS1 IHC, genotyping (SNaPshot© +/- high-throughput genotyping) and sometimes FISH (standard routine process) were tested prospectively in parallel with the LD-RT-PCR assay designed to detect at one go ALK, ROS1 and RET translocations and MET exon 14 skipping. 413 tumors from 396 patients were included. LD-RT-PCR had a global sensitivity of 91.43% (standard routine process: 80%), with a specificity of 100%. It detected 15/18 ALK and 4/4 ROS1 translocated tumors, but also 6/6 tumors with MET exon 14 skipping retrieved by genotyping. In addition, it retrieved 7 alterations missed by the routine process, then confirmed by other means: 5 MET exon 14 skipping and 2 RET translocated tumors. Finally, it allowed to deny an effect on MET exon 14 skipping for 8 mutations detected by routine genotyping. We successfully implemented LD-RT-PCR in routine analysis. This technique is cheap, fast, sensitive, specific, and easily upgradable (e.g., NTRK translocations), but still requires IHC to be performed in parallel. Owing to its advantages, we recommend considering it, in parallel with IHC and genotyping, as an excellent cost-effective alternative, for the systematic testing of lung adenocarcinoma, to FISH and to more expensive and complex assays such as RNA-seq.