Sotorasib for Vascular Malformations Associated with KRAS G12C Mutation.

KRAS gain-of-function mutations are frequently observed in sporadic arteriovenous malformations. The mechanisms underlying the progression of such KRAS-driven malformations are still incompletely understood, and no treatments for the condition are approved. Here, we show the effectiveness of sotorasib, a specific KRAS G12C inhibitor, in reducing the volume of vascular malformations and improving survival in two mouse models carrying a mosaic Kras G12C mutation. We then administered sotorasib to two adult patients with severe KRAS G12C-related arteriovenous malformations. Both patients had rapid reductions in symptoms and arteriovenous malformation size. Targeting KRAS G12C appears to be a promising therapeutic approach for patients with KRAS G12C-related vascular malformations. (Funded by the European Research Council and others.).

Characteristics of H3K27M-mutant diffuse gliomas with a non-midline location.

PURPOSE: Diffuse midline gliomas (DMG) with H3K27 alterations (H3K27M-DMG) are a highly aggressive form of brain cancer. In rare cases, H3K27 mutations have been observed in diffuse non-midline gliomas (DNMG). It is currently unclear how these tumors should be classified. Herein, we analyze the characteristics of DNMG with H3K27M mutations. METHODS: We reviewed the clinical, radiological and histological characteristics of all patients with an H3K27M mutated diffuse glioma diagnosed in our institution, between 2016 and 2023, to identify cases with a non-midline location. We then performed a molecular characterization (DNA methylation profiling, whole genome and transcriptome sequencing or targeted sequencing) of patients with an H3K27M-mutant DNMG and reviewed previously reported cases. RESULTS: Among 51 patients (18 children and 33 adults) diagnosed with an H3K27M diffuse glioma, we identified two patients (4%) who had a non-midline location. Including our two patients, 39 patients were reported in the literature with an H3K27M-mutant DNMG. Tumors were most frequently located in the temporal lobe (48%), affected adolescents and adults, and were associated with a poor outcome (median overall survival was 10.3 months (0.1-84)). Median age at diagnosis was 19.1 years. Tumors frequently harbored TP53 mutations (74%), ATRX mutations (71%) and PDGFRA mutations or amplifications (44%). In DNA methylation analysis, H3K27M-mutant DNMG clustered within or close to the reference group of H3K27M-mutant DMG. Compared to their midline counterpart, non-midline gliomas with H3K27M mutations seemed more frequently associated with PDGFRA alterations. CONCLUSION: DNMG with H3K27M mutations share many similarities with their midline counterpart, suggesting that they correspond to a rare anatomical presentation of these tumors. This is of paramount importance, as they may benefit from new therapeutic approaches such as ONC201.

Comparison and Validation of Rapid Molecular Testing Methods for Theranostic Epidermal Growth Factor Receptor Alterations in Lung Cancer: Idylla versus Digital Droplet PCR.

Targeting EGFR alterations, particularly the L858R (Exon 21) mutation and Exon 19 deletion (del19), has significantly improved the survival of lung cancer patients. From now on, the issue is to shorten the time to treatment. Here, we challenge two well-known rapid strategies for EGFR testing: the cartridge-based platform Idylla™ (Biocartis) and a digital droplet PCR (ddPCR) approach (ID_Solution). To thoroughly investigate each testing performance, we selected a highly comprehensive cohort of 39 unique del19 (in comparison, the cbioportal contains 40 unique del19), and 9 samples bearing unique polymorphisms in exon 19. Additional L858R (N = 24), L861Q (N = 1), del19 (N = 63), and WT samples (N = 34) were used to determine clear technical and biological cutoffs. A total of 122 DNA samples extracted from formaldehyde-fixed samples was used as input. No false positive results were reported for either of the technologies, as long as careful droplet selection (ddPCR) was ensured for two polymorphisms. ddPCR demonstrated higher sensitivity in detecting unique del19 (92.3%, 36/39) compared to Idylla (67.7%, 21/31). However, considering the prevalence of del19 and L858R in the lung cancer population, the adjusted theranostic values were similar (96.51% and 95.26%, respectively). ddPCR performs better for small specimens and low tumoral content, but in other situations, Idylla is an alternative (especially if a molecular platform is absent).

[Differential diagnostic between hepatocellular carcinoma and hepatoid carcinoma with bone metastasis revelation: What tools can be used?] / Diagnostic différentiel entre un carcinome hépatocellulaire et un carcinome hépatoïde à révélation métastatique osseuse : quels outils sont à disposition ?

Bone metastases of hepatocellular carcinoma (HCC) are rare and disease-revealing bone metastasis are exceptional. Here, we report the case of a 69-year-old man with a cervical vertebral metastasis of hepatocellular carcinoma. Morphological aspect of a metastatic tumor with eosinophilic and polygonal cells raises the question of the differential diagnosis between a localization of a hepatocellular carcinoma or an hepatoid carcinoma, notably when the metastasis is the first clinical manifestation. The morphological aspect by itself does not provide strong enough arguments for diagnosis. Well selected immunohistochemical markers can sometimes help to orientate towards one of the two hypotheses, in particular SALL4 and LIN28 which are in favour of hepatoid carcinoma when both are positive. Finally, as these two entities have different molecular profiles, molecular study can also be helpful to distinguish them. Indeed, HCCs often present TERT promoter, CTNNB1 mutations and IL-6/JAK/STAT pathway activation while hepatoid adenocarcinoma frequently presents chromosome 20 long arm gain. TP53 mutations are found in both entities and are therefore not discriminating. Differential diagnosis is important because the treatment will be that of the primary. Prognostic data for HCC revealed by bone metastasis are scarce, although they seem to be associated with a poor prognosis, with a 1 to 2 months overall survival. There is currently no data for hepatoid adenocarcinoma with bone metastasis.

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.

Evaluating Targeted Next-Generation Sequencing Assays and Reference Materials for NTRK Fusion Detection.

Neurotrophic tyrosine receptor kinase (NTRK1/2/3) fusions are oncogenic drivers in approximately 0.3% of solid tumors. High-quality testing to identify patients with NTRK fusion-positive tumors who could benefit from tropomyosin receptor kinase inhibitors is recommended, but the current NTRK testing landscape, including next-generation sequencing (NGS), is fragmented and availability of assays varies widely. The analytical and clinical performance of four commonly available RNA-based NGS assays, Archer's FusionPlex Lung panel (AFL), Illumina's TruSight Oncology 500 (TSO500), Thermo Fisher's Oncomine Precision Assay and Oncomine Focus Assay (OFA), were evaluated. Experiments were conducted using contrived samples [formalin-fixed, paraffin-embedded cell lines and SeraSeq formalin-fixed, paraffin-embedded reference material], NTRK fusion-negative clinical samples, and NTRK fusion-positive clinical samples, according to local assays. Estimated limit of detection varied across the four assays: 30 to 620 fusion copies for AFL (cell lines), versus approximately 30 to 290 copies for TSO500 and approximately 1 to 28 copies for OFA and Oncomine Precision Assay. All assays showed 100% specificity for NTRK fusions detection, but quality control pass rate was variable (AFL, 43%; TSO500, 77%; and OFA, 83%). The NTRK fusion detection rate in quality control-validated clinical samples was 100% for all assays. This comparison of the strengths and limitations of four RNA-based NGS assays will inform physicians and pathologists regarding optimal assay selection to identify patients with NTRK fusion-positive tumors.

Uncommon EGFR mutations in lung adenocarcinoma: features and response to tyrosine kinase inhibitors.

BACKGROUND: EGFR mutant non-small cell lung cancer (NSCLC) is a heterogeneous disease. The treatment for frequent EGFR mutations relies on tyrosine kinase inhibitors (TKIs); the clinical and therapeutic significance of uncommon EGFR mutations is uncertain. METHODS: This is a single-center retrospective study of patients with EGFR-mutant lung cancer (2009-2017). Molecular analyses of EGFR exons 18-21 were performed. Only patients with uncommon mutations were included (p.Glu709X, p.Gly719X, p.Ala767_Val769 dup, p.Ser768Ile, and p.Leu861Gln). RESULTS: Among 6,747 tumor samples, 95 out 820 patients (11.6%) harbored 113 uncommon EGFR mutations. There were 50 metastatic NSCLC patients for whom the median OS was 18.0 months (95% CI: 15, 32). In this population, the p.Leu861Gln uncommon exon 21 EGFR mutation was associated with poor prognosis (HR: 2.96, 95% CI: 1.39, 6.31; P=0.003). Among those harboring a single uncommon EGFR mutation, median OS was 27.6 months (95% CI: 10.8, not attained) in patients who were treated by chemotherapy only (n=13) versus 6.0 months (95% CI: 2.4, not attained) in patients exclusively treated with a first or second-EGFR-TKI (n=9; HR: 0.27, 95% CI: 0.09, 0.78; P=0.01. In patients with a single uncommon EGFR mutation, first-line chemotherapy was associated with a better overall survival than TKIs (HR: 0.31, 95% CI: 0.15, 0.68; P=0.002). In patients who received first or second-EGFR-TKI as first-line treatment (n=26), OS was significantly better for those with two uncommon EGFR mutations than those with a single uncommon mutation (HR: 0.07, 95% CI: 0.009, 0.54; P=0.001). CONCLUSIONS: In conclusion, uncommon EGFR mutations may be associated with a poor outcome and the data challenge the use of first-generation TKI in such patients, however first-line TKI is more effective in cases of double uncommon mutations and such patients should be treated accordingly.

Frequency of MET exon 14 skipping mutations in non-small cell lung cancer according to technical approach in routine diagnosis: results from a real-life cohort of 2,369 patients.

BACKGROUND: Mesenchymal epithelial transition receptor (MET) alterations, including MET exon 14 skipping mutation, are oncogenic in non-small cell lung cancer (NSCLC) and may confer sensitivity to targeted therapy. Given the rarity and the diversity of exon 14 skipping mutations, diagnosis may be challenging on small-biopsy specimens. METHODS: Between March 2014 and May 2018, tissue samples from patients with metastatic NSCLC were analysed for MET exon 14 skipping mutation as part of routine practice in the Pathology Department of the Hospices Civils de Lyon, France. Over the study period, Sanger sequencing and/or two different DNA-based next generation sequencing (NGS) assays were used. RESULTS: Genomic alterations of MET exon 14 were detected in 2.6% (62/2,369) samples of NSCLC analysed for MET exon 14 mutations. Patients were mainly women (38/62, 61%) without smoking history (22/39, 56%) and the median age was 75 years. MET exon 14 skipping mutations were diagnosed by NGS in 50 cases and by classical Sanger sequencing in 12 cases. The frequency of MET mutations was 15.4% when Sanger sequencing was performed at the request of the clinician and 4.1% when the DNA-based NGS assay coverage included the 3' and 5' parts of the MET exon 14 and performed systematically. CONCLUSIONS: The frequency of genomic alterations is highly dependent on patient selection and the technical approach.

Inequity in access to personalized medicine in France: Evidences from analysis of geo variations in the access to molecular profiling among advanced non-small-cell lung cancer patients: Results from the IFCT Biomarkers France Study.

In this article, we studied geographic variation in the use of personalized genetic testing for advanced non-small cell lung cancer (NSCLC) and we evaluated the relationship between genetic testing rates and local socioeconomic and ecological variables. We used data on all advanced NSCLC patients who had a genetic test between April 2012 and April 2013 in France in the frame of the IFCT Biomarqueurs-France study (n = 15814). We computed four established measures of geographic variation of the sex-adjusted rates of genetic testing utilization at the "départment" (the French territory is divided into 94 administrative units called 'départements') level. We also performed a spatial regression model to determine the relationship between département-level sex-adjusted rates of genetic testing utilization and economic and ecological variables. Our results are the following: (i) Overall, 46.87% lung cancer admission patients obtained genetic testing for NSCLC; département-level utilization rates varied over 3.2-fold. Measures of geographic variation indicated a relatively high degree of geographic variation. (ii) there was a statistically significant relationship between genetic testing rates and per capita supply of general practitioners, radiotherapists and surgeons (negative correlation for the latter); lower genetic testing rates were also associated with higher local poverty rates. French policymakers should pursue effort toward deprived areas to obtain equal access to personalized medicine for advanced NSCLC patients.

Lipofibromatosis-Like Neural Tumor: A Case Report and Review of the Literature.

Lipofibromatosis-like neural tumors (LPF-NT) are soft tissue tumors characterized by a lipofibromatosis-like pattern, CD34/PS100 positivity, and recurrent NTRK1 gene rearrangement. It occurs mainly in pediatric patients or young adults. We report here, the first case of LPF-NT in a middle-aged adult initially misdiagnosed as a myoepithelial tumor. LPF-NT may have a locally aggressive course but no recurrence was seen after complete surgeries, whereas metastatic diseases remain exceptional.

Outcomes of Patients With Advanced NSCLC From the Intergroupe Francophone de Cancérologie Thoracique Biomarkers France Study by KRAS Mutation Subtypes.

INTRODUCTION: KRAS mutations are detected in 20% to 30% of NSCLC. However, KRAS mutation subtypes may differently influence the outcome of patients with advanced NSCLC. METHODS: In the Biomarkers France study, 4894 KRAS mutations (26.2%) were detected in 4634 patients from the 17,664 enrolled patients with NSCLC. Survival and treatment data on noncurative stage III to IV NSCLC were available for 901 patients. First- and second-line treatment effects on progression-free survival and overall survival were analyzed according to the KRAS mutations subtype. RESULTS: Over 95% of patients with KRAS mutation were smokers or former smokers who were white (99.5%), presenting with adenocarcinoma (82.5%). The most common KRAS mutation subtype was G12C (374 patients; 41.5%), followed by G12V (168; 18.6%), G12D (131; 14.5%), G12A (62; 6.9%), G13C (45; 5.0%), G13D (31; 3.4%), and others (10; 1%). Approximately 21% of patients had transition mutation and 68.2% had a transversion mutation. G12D and transition mutations were predominant in never-smokers. The median overall survival for patients with KRAS-mutated NSCLC was 8.1 months (95% confidence interval [CI]: 7.5-9.5), without any differences according to the different KRAS subtypes mutations. The median progression-free survival was 4.6 months (95% CI: 4.2-5.1) for first-line treatment and 4.8 months (95% CI: 4.3-6.8) for second-line treatment, without any differences according to the different KRAS subtypes mutations. CONCLUSIONS: KRAS mutation subtypes influenced neither treatment responses nor outcomes. The KRAS G12C mutation was detected in 41.5% of patients, who are now eligible for potent and specific G12C inhibitors.

Independent prognostic value of ultra-sensitive quantification of tumor pre-treatment T790M subclones in EGFR mutated non-small cell lung cancer (NSCLC) treated by first/second generation TKI, depends on variant allele frequency (VAF): Results of the French cooperative thoracic intergroup (IFCT) biomarkers France project.

OBJECTIVES: T790M mutations inEGFR-mutated non-small cell lung cancer (NSCLC) account for nearly 50% of acquired resistance mechanisms to EGFR-TKIs. Earlier studies suggested that tumor T790M could also be detected in TKI-naïve EGFR-mutated NSCLC. The aim of the study is to assess the prevalence and clinical significance of quantification of tumor pre-treatment T790M subclones. MATERIALS AND METHODS: We analyzed 366 EGFR-mutated NSCLC patients of the real-life IFCT Biomarkers France study with available pre-treatment formalin-fixed paraffin-embedded (FFPE) tumor DNA before treatment by first/second-generation EGFR-TKI. We used ultra-sensitive Droplet Digital Polymerase Chain Reaction (ddPCR) QX200 (BIO-RAD®, Hercules, CA, USA). All samples were tested in duplicate. RESULTS: ddPCR identified T790M in 19/240 specimens (8%). T790M-positive and T790M-negative populations were not different for clinical baseline characteristics. T790M Variant Allele Frequency (VAF) was > 0.01% <0.1%, > 0.1% <1%, > 1% <10%, and >10% in five (26.3%), six (31.6%), six (31.6%), and two (10.5%) patients, respectively. T790M VAF was >0.1% in 11/13 (84%) patients with rapid (<3 months) or usual progression (3-20 months) compared to 0/3 with low progression (>20 months) (p = 0.02). In a Cox model, T790M mutation positivity was correlated with overall survival (OS) and progression-free survival (PFS) for 10% > VAF >1% (hazard ratio [HR] = 2.83, 95% confidence interval [CI] 1.13-7.07, p = 0.03; HR=3.62, 95%CI 1.43-4.92, p = 0.007, respectively) and for VAF >10% (HR = 19.14, 95%CI 4.35-84.26, p < 0.001; HR = 17.89, 95%CI 2.21-144.86, p = 0.007, respectively). CONCLUSION: Ultra-sensitive detection of tumor T790M mutation concerned 8% of EGFR-mutated TKI-naïve NSCLC patients and has a negative prognostic value only for T790M VAF over 1%.

Compliance to regional recommendations for molecular analyses and management of advanced lung cancer patients.

Aim: We performed a clinical audit of the management of patients with EGFR mutations, 1 year after the introduction of EGFR tyrosine kinase inhibitor (EGFR-TKI) in first-line treatment. Methods: Compliance was defined by tumor molecular profiling for stage IIIB and IV non-small-cell lung cancer and first-line treatment as recommended by the French guidelines. Results: Among the 169 EGFR-mutated patients, compliance was 76.4%. The most common noncompliance criterion was chemotherapy given in first-line treatment instead of EGFR-TKI. No dedicated multidisciplinary meeting and type of institutions were independent unfavorable predictors for compliance. Compliance to guidelines was significantly correlated with time-to-first subsequent treatment improvement (2.5 vs 9.1 months; p < 0.0001). Conclusion: Implementation of new standards of care is challenging. Our results reinforce the role of multidisciplinary meetings to provide a better access to innovating therapeutics.

Clinical outcomes of non-small-cell lung cancer patients with BRAF mutations: results from the French Cooperative Thoracic Intergroup biomarkers France study.

INTRODUCTION: Patients with stage IV non-small-cell lung cancer (NSCLC) and BRAF V600 mutations may benefit from targeted therapies. Chemotherapy outcomes are little known in this population. METHODS: The French Cooperative Thoracic Intergroup (IFCT) Biomarkers France study was a national prospective cohort study aiming to describe the molecular characteristics and clinical outcome of all consecutive NSCLC patients (N = 17,664) screened for molecular alterations. We used this data set to set up a case-control analysis. Cases had stage IV BRAF-mutated (BRAF-MT) NSCLC, whereas controls had NSCLC that was wild-type for EGFR, KRAS, HER2, BRAF, PIK3CA and ALK. Each case was matched for sex, age at diagnosis and smoking status to two controls randomly selected. RESULTS: Overall, 83 cases with BRAF mutant disease (66.3% V600E) were matched to 166 controls. Five cases received tyrosine kinase inhibition in the first-line and 16 in the second-line. All others were treated with standard chemotherapy. There was no significant difference in first-line and second-line progression-free survival (PFS) between the groups, as well as in the disease control rate, BRAF mutation was not found to be prognostic of overall survival. We found no significant difference in outcome between the treatment types used in first-line or second-line in patients with BRAF-MT disease compared with controls nor between BRAF V600E or non-V600E compared with controls. CONCLUSIONS: BRAF mutation is not a strong prognostic factor in NSCLC. Although taxan-based therapy shows poorest PFS in first-line, no chemotherapy regimen was associated with prognosis.

A Multiplex Quantitative Reverse Transcription Polymerase Chain Reaction Assay for the Detection of KIAA1549-BRAF Fusion Transcripts in Formalin-Fixed Paraffin-Embedded Pilocytic Astrocytomas.

BACKGROUND AND OBJECTIVE: Genomic duplications and fusion involving BRAF and KIAA1549 that create fusion proteins with constitutive B-RAF kinase activity are a hallmark of pilocytic astrocytomas (PAs). The detection of KIAA1549-BRAF fusion transcripts is of paramount importance to classify these tumors and to identify patients who could benefit from BRAF inhibitors. In a clinical setting, the available material for molecular analysis from these pediatric tumors is often limited to formalin-fixed paraffin-embedded (FFPE) tissue. The aim of the present study was to develop a new method to detect the three most frequent KIAA1549-BRAF fusion transcripts, 15-9, 16-11, and 16-9, where numbers refer to the exons fused together, using a FFPE-compatible multiplex quantitative reverse transcription polymerase chain reaction (qRT-PCR). METHODS: We compared performance of the assay to a reference singleplex method on a collection of 46 FFPE PAs. RESULTS: The results showed that both methods are comparable. The multiplex method had an overall 97% sensitivity and 100% specificity compared to the singleplex method, and agreement between the two techniques was almost perfect (Cohen's kappa: 0.97). There was no evidence of a significant difference between the qRT-PCR efficiencies of the multiplex technique and of the singleplex assay for all fusion transcripts and for GAPDH, the latter used as a reference gene. The multiplex method consumed four times less complementary DNA (cDNA), cost less, and required half the hands-on technical time. CONCLUSION: The results show that it could be beneficial to implement the multiplex method in a clinical setting, where samples presenting low quantity of degraded RNA are not unusual.

Cross-platform comparison for the detection of RAS mutations in cfDNA (ddPCR Biorad detection assay, BEAMing assay, and NGS strategy).

CfDNA samples from colon (mCRC) and non-small cell lung cancers (NSCLC) (CIRCAN cohort) were compared using three platforms: droplet digital PCR (ddPCR, Biorad); BEAMing/OncoBEAM™-RAS-CRC (Sysmex Inostics); next-generation sequencing (NGS, Illumina), utilizing the 56G oncology panel (Swift Biosciences). Tissue biopsy and time matched cfDNA samples were collected at diagnosis in the mCRC cohort and during 1st progression in the NSCLC cohort. Excellent matches between cfDNA/FFPE mutation profiles were observed. Detection thresholds were between 0.5-1% for cfDNA samples examined using ddPCR and NGS, and 0.03% with BEAMing. This high level of sensitivity enabled the detection of KRAS mutations in 5/19 CRC patients with negative FFPE profiles. In the mCRC cohort, comparison of mutation results obtained by testing FFPE to those obtained by testing cfDNA by ddPCR resulted in 47% sensitivity, 77% specificity, 70% positive predictive value (PPV) and 55% negative predictive value (NPV). For BEAMing, we observed 93% sensitivity, 69% specificity, 78% PPV and 90% NPV. Finally, sensitivity of NGS was 73%, specificity was 77%, PPV 79% and NPV 71%. Our study highlights the complementarity of different diagnostic approaches and variability of results between OncoBEAM™-RAS-CRC and NGS assays. While the NGS assay provided a larger breadth of coverage of the major targetable alterations of 56 genes in one run, its performance for specific alterations was frequently confirmed by ddPCR results.

[Multiple lung carcinoma: Primary or intrapulmonary metastasis?] / Adénocarcinomes pulmonaires multiples : primitifs ou métastases ?

Multiple lung carcinomas are 5 to 11,5% of lung carcinomas. The distinction between primary lung carcinomas from carcinomas with intrapulmonary metastasis is essential for optimal patient management. The histopathological analysis is very useful but it has to be completed by genotypic assessment using molecular biology (NGS). Molecular biology can also identify genetic alterations with therapeutic implications. We present the case of a patient with a history of surgery for multiple lung carcinomas diagnosed from 2013 to 2017.

Evaluation of pre-analytical conditions and comparison of the performance of several digital PCR assays for the detection of major EGFR mutations in circulating DNA from non-small cell lung cancers: the CIRCAN_0 study.

Non invasive somatic detection assays are suitable for repetitive tumor characterization or for detecting the appearance of somatic resistance during lung cancer. Molecular diagnosis based on circulating free DNA (cfDNA) offers the opportunity to track the genomic evolution of the tumor, and was chosen to assess the molecular profile of several EGFR alterations, including deletions in exon 19 (delEX19), the L858R substitution on exon 21 and the EGFR resistance mutation T790M on exon 20. Our study aimed at determining optimal pre-analytical conditions and EGFR mutation detection assays for analyzing cfDNA using the picoliter-droplet digital polymerase chain reaction (ddPCR) assay. Within the framework of the CIRCAN project set-up at the Lyon University Hospital, plasma samples were collected to establish a pre-analytical and analytical workflow of cfDNA analysis. We evaluated all of the steps from blood sampling to mutation detection output, including shipping conditions (4H versus 24H in EDTA tubes), the reproducibility of cfDNA extraction, the specificity/sensitivity of ddPCR (using external controls), and the comparison of different PCR assays for the detection of the three most important EGFR hotspots, which highlighted the increased sensitivity of our in-house primers/probes. Hence, we have described a new protocol facilitating the molecular detection of somatic mutations in cancer patients from liquid biopsies, improving their diagnosis and introducing a less traumatic monitoring system during tumor progression.