c-Met immunohistochemistry as reflex test at diagnosis for non-small cell lung cancer: a real-world experience from a monocentric case series.

AIMS: Recent clinical trials have shown promising results with drugs targeting the hepatocyte growth factor receptor (c-Met) for advanced non-small cell lung cancers overexpressing c-Met. We assessed reflex testing of c-Met immunohistochemistry (IHC) at diagnosis for NSCLC in the real-world. METHODS: We retrospectively collected clinical, pathological and molecular data of cases diagnosed with NSCLC in our institution from January 2021 to June 2023. We performed c-Met IHC (SP44 clone) and scored the expression using a H-score and a three-tier classification. RESULTS: 391 cases with interpretable c-Met IHC staining were included. The median age at diagnosis was 70 years (range 25-89 years) including 234 males (male/female ratio 1:5). 58% of the samples came from surgical resections, 35% from biopsies and 8% from cytological procedures. 52% of cases were classified as c-Met-positive (H-score≥150) and 19% were classified as c-Methigh (≥50%, 3+). 43% of the c-Metneg presented with lymph node and/or visceral metastases at diagnosis vs 55% for c-Methigh (p=0.042). 23% of the adenocarcinomas showed c-Methigh expression vs 3% for squamous cell carcinomas (p=0.004). 27% of the c-Metneg cases had a high PD-L1 expression vs 58% of c-Methigh cases (p<0.001). MET ex14 skipping was present in 8% of the c-Methigh cases. CONCLUSIONS: Systematic c-Met testing in daily routine for NSCLC patients is feasible, highlighting a potential correlation with clinicopathological and molecular features.

Ultra-Fast Amplicon-Based Next-Generation Sequencing in Non-Squamous Non-Small Cell Lung Cancer.

The number of molecular alterations to be tested for targeted therapy of non-squamous non-small cell lung cancer (NS-NSCLC) patients has significantly increased these last few years. The detection of molecular abnormalities is mandatory for the optimal care of advanced or metastatic NS-NSCLC patients, allowing targeted therapies to be administrated with an improvement in overall survival. Nevertheless, these tumors develop mechanisms of resistance that are potentially targetable using novel therapies. Some molecular alterations can also modulate the treatment response. The molecular characterization of NS-NSCLC has to be performed in a short turnaround time (TAT), in less than 10 working days, as recommended by the international guidelines. In addition, the origin of the tissue biopsies for genomic analysis is diverse, and their size is continuously decreasing with the development of less invasive methods and protocols. Consequently, pathologists are being challenged to perform effective molecular technics while maintaining an efficient and rapid diagnosis strategy. Here, we describe the ultra-fast amplicon-based next-generation sequencing (NGS) workflow used in daily routine practice at diagnosis for NS-NSCLC patients. We showed that this system is able to identify the current molecular targets used in precision medicine in thoracic oncology in an appropriate TAT.

The Need to Set up a Biobank Dedicated to Lymphoid Malignancies: Experience of a Single Center (Laboratory of Clinical and Experimental Pathology, University Côte d'Azur, Nice, France).

Several therapies to improve the management of lymphoma are currently being investigated, necessitating the development of new biomarkers. However, this requires high-quality and clinically annotated biological material. Therefore, we established a lymphoma biobank including all available biological material (tissue specimens and matched biological resources) along with associated clinical data for lymphoma patients diagnosed, according to the WHO classification, between 2005 and 2022 in the Laboratory of Clinical and Experimental Pathology, Nice, France. We retrospectively included selected cases in a new collection at the Côte d'Azur Biobank, which contains 2150 samples from 363 cases (351 patients). The male/female ratio was 1.3, and the median age at diagnosis was 58 years. The most common lymphoma types were classical Hodgkin lymphoma, diffuse large B-cell lymphoma, and extra-nodal marginal zone lymphoma of MALT tissue. The main sites of lymphoma were the mediastinum, lymph node, Waldeyer's ring, and lung. The Côte d'Azur Biobank is ISO 9001 and ISO 20387 certified and aims to provide high quality and diverse biological material to support translational research projects into lymphoma. The clinico-pathological data generated by this collection should aid the development of new biomarkers to enhance the survival of patients with lymphoid malignancies.

A Real-World Experience from a Single Center (LPCE, Nice, France) Highlights the Urgent Need to Abandon Immunohistochemistry for ROS1 Rearrangement Screening of Advanced Non-Squamous Non-Small Cell Lung Cancer.

The detection of ROS1 rearrangements in metastatic non-squamous non-small cell lung carcinoma (NS-NSCLC) permits administration of efficient targeted therapy. Detection is based on a testing algorithm associated with ROS1 immunohistochemistry (IHC) screening followed by ROS1 FISH and/or next generation sequencing (NGS) to confirm positivity. However, (i) ROS1 rearrangements are rare (1-2% of NS-NSCLC), (ii) the specificity of ROS1 IHC is not optimal, and (iii) ROS1 FISH is not widely available, making this algorithm challenging to interpret time-consuming. We evaluated RNA NGS, which was used as reflex testing for ROS1 rearrangements in NS-NSCLC with the aim of replacing ROS1 IHC as a screening method. ROS1 IHC and RNA NGS were prospectively performed in 810 NS-NSCLC. Positive results were analyzed by ROS1 FISH. ROS1 IHC was positive in 36/810 (4.4%) cases that showed variable staining intensity while NGS detected ROS1 rearrangements in 16/810 (1.9%) cases. ROS1 FISH was positive in 15/810 (1.8%) of ROS1 IHC positive cases and in all positive ROS1 NGS cases. Obtaining both ROS1 IHC and ROS1 FISH reports took an average of 6 days, while obtaining ROS1 IHC and RNA NGS reports took an average of 3 days. These results showed that systematic screening for the ROS1 status using IHC must be replaced by NGS reflex testing.

Lack of correlation between MET and PD-L1 expression in non-small cell lung cancer revealed by comparative study of matched biopsies and surgical resection samples.

INTRODUCTION: Both MET expression and the PD-L1 tumor proportion score (TPS) are companion diagnostics for treatment of advanced non-small cell lung carcinoma (aNSCLC) patients. We evaluated the rate of correlation between MET expression and the PD-L1 TPS in matched biopsies and surgically resected specimens from NSCLC patients. PATIENTS AND METHODS: This retrospective analysis assessed the prevalence and correlation between MET expression (SP44 clone) and the PD-L1 TPS (22C3 clone) by immunohistochemistry together with molecular alterations determined by targeted next-generation sequencing in matched lung biopsy and surgically lung resected specimens from 70 patients with NSCLC. RESULTS: The study found a significant correlation between the MET H-score in surgical samples and matched biopsies (P-value < 0.0001), as well as between the PD-L1 TPS in paired biopsies and surgical samples (P-value < 0.0001). However, there was no significant correlation between the MET H-score or expression subgroups and the PD-L1 TPS in both types of paired samples (P-value = 0.47, and P-value = 0.90). The MET H-score was significantly higher in adenocarcinoma compared to squamous cell carcinoma (P-value < 0.0001). A mutational analysis showed that the MET H-score was significantly higher in NSCLC cases with targetable molecular alterations (P-value = 0.0095), while no significant correlation was found for the PD-L1 TPS. CONCLUSIONS: Our study found no significant correlation between PD-L1 and MET expression in samples from NSCLC patients, highlighting the importance of personalized treatment strategies based on individual expression profiles. These findings provide valuable insight into the development of effective immunotherapy and targeted therapy for NSCLC patients.

Vanished MDM2 amplification in multiple recurrences of an irradiated poorly differentiated sarcoma with amplified TRIO::TERT fusion gene.

Among sarcomas, MDM2 amplification is usually a molecular hallmark of well-differentiated liposarcoma and dedifferentiated liposarcoma (DDLPS) and occasionally a secondary genetic anomaly in other sarcomas. Histological evaluation and FISH analysis showing MDM2 amplification led to the diagnosis of DDLPS for a tumor located on the left arm of a 71-year-old patient. The patient was treated by adjuvant radiotherapy (RT) but the tumor recurred soon after. Array-comparative genomic hybridization and targeted RNA/DNA sequencing of the primary tumor and of four recurrences were done. Strikingly, the MDM2 amplification observed in the primary tumor had vanished in the recurrences. In contrast, other rearrangements, such as amplification of the genes TRIO and TERT as well as TRIO::TERT fusion were detected retrospectively in the primary tumor and in all the recurrences. The transitory nature of the MDM2 amplification raised the hypothesis that RT was active on cells that contained MDM2 amplification but not on other tumor cells with only the TERT and TRIO alterations. In contrast to MDM2 amplification, the TRIO::TERT amplified fusion was stable over time. The detection of this fusion was crucial in the analysis of the diagnostically challenging last tumor; it allowed to determine that it was a fourth recurrence, instead of a new independent tumor. It also suggested the diagnosis undifferentiated pleomorphic sarcoma rather than DDLPS. The TRIO::TERT fusion is not well explored. The current study shows that its role in sarcomas, with or without MDM2 amplification, should be more extensively researched.

Prognostic Biomarkers in Uveal Melanoma: The Status Quo, Recent Advances and Future Directions.

Uveal melanoma (UM) is the most common malignant intraocular tumour in the adult population. It is a rare cancer with an incidence of nearly five cases per million inhabitants per year, which develops from the uncontrolled proliferation of melanocytes in the choroid (≈90%), ciliary body (≈6%) or iris (≈4%). Patients initially present either with symptoms like blurred vision or photopsia, or without symptoms, with the tumour being detected in routine eye exams. Over the course of the disease, metastases, which are initially dormant, develop in nearly 50% of patients, preferentially in the liver. Despite decades of intensive research, the only approach proven to mildly control disease spread are early treatments directed to ablate liver metastases, such as surgical excision or chemoembolization. However, most patients have a limited life expectancy once metastases are detected, since there are limited therapeutic approaches for the metastatic disease, including immunotherapy, which unlike in cutaneous melanoma, has been mostly ineffective for UM patients. Therefore, in order to offer the best care possible to these patients, there is an urgent need to find robust models that can accurately predict the prognosis of UM, as well as therapeutic strategies that effectively block and/or limit the spread of the metastatic disease. Here, we initially summarized the current knowledge about UM by compiling the most relevant epidemiological, clinical, pathological and molecular data. Then, we revisited the most important prognostic factors currently used for the evaluation and follow-up of primary UM cases. Afterwards, we addressed emerging prognostic biomarkers in UM, by comprehensively reviewing gene signatures, immunohistochemistry-based markers and proteomic markers resulting from research studies conducted over the past three years. Finally, we discussed the current hurdles in the field and anticipated the future challenges and novel avenues of research in UM.