Clinical Utility and Outcomes Impact of Crystal Digital PCR of Sensitizing and Resistance EGFR Mutations in Patients With Advanced Non-Small Cell Lung Cancer.

BACKGROUND: EGFRm represent 15% of advanced NSCLC in European patients. LB for molecular profiling offers a non-invasive alternative to tissue. cdPCR is a high-sensitive and low-cost LB to detect molecular alterations. We aimed to describe cdPCR clinical utility for EGFRm detection in advanced NSCLC. METHODS: Prospective blood sample collection in patients with advanced NSCLC harbouring EGFRm either at diagnosis, under response or at PD between January 16 and September 20 at Gustave Roussy. LB was performed by cdPCR (Stilla): sensitizing (exon19; exon21 [p.L858R]) and exon 20 p.T790M resistance EGFRm. We defined high tumour burden (high-TB) as >2 metastatic sites. We analysed EGFRm detection by cdPCR and its correlation with progression-free and overall survival (PFS, OS). RESULTS: A total of 252 blood samples were collected in 140 patients. At baseline (n=25), sensitizing EGFRm were detected in 64% of samples, 88% in patients with high-TB (n=8) and 40% among those with intracranial/intrathoracic isolated lesions (n=5). At PD to tyrosine-kinase inhibitors (TKI) (n=117), detection rate (sensitizing EGFRm) was 56%; 30% in patients with intracranial/thoracic isolated lesions (n=37) vs. 67% in those with high-TB (n=63). At PD to first/second generation TKI (n=81), the p.T790M mutation was found in 22% (18/81); detection rate was 9% for intracranial/thoracic (n=23) vs. 32% for high-TB (n=41) cases. The clearance of EGFRm allelic frequency was correlated with radiological response. The absence of EGFRm detection at TKI-failure was associated with longer OS (39.1 vs. 18.4 months; P=.02). CONCLUSIONS: cdPCR is a sensitive LB for sensitizing and resistance EGFRm detection. cdPCR positivity was more likely observed in systemic PD cases with high-TB. It is a low-cost EGFRm detecting approach to guide treatment in NSCLC, however metastatic profile should be taken into account.

6-Color Crystal Digital PCRTM for the High-Plex Detection of EGFR Mutations in Non-Small Cell Lung Cancer.

The profiling of EGFR mutations, the most common genetic alterations in non-small cell lung cancer (NSCLC) predictive of targeted therapy efficacy, is crucial to anticipate the patient response to EGFR tyrosine kinase inhibitors. Here, we introduce the naica® system for 6-color Crystal Digital PCRTM and describe in detail a standardized workflow for the multiplexed, single-assay detection of the 19 most prevalent sensitizing and resistance EGFR mutations in both tumor and circulating tumor DNA (ctDNA) samples. Two major advantages of the 6-color multiplexing system over current digital PCR systems are the rapid time to results, and the large quantity of mutational information obtained per patient sample, rendering the 6-color system highly cost effective. The 6-color Crystal Digital PCRTM technology enables highly sensitive and efficient therapeutic monitoring through liquid biopsy, resulting in the early detection of treatment resistance. While the assay presented here specifically addresses EGFR mutation status monitoring in NSCLC patients, 6-color Crystal Digital PCRTM assays are flexible and evolutive in design. As such, 6-color detection assays can be optimized to monitor mutations associated with a range of cancers and other genetic diseases, as well as to detect genetic changes beyond the oncology and human health domains.

Chronic Plasma Exposure to Kinase Inhibitors in Patients with Oncogene-Addicted Non-Small Cell Lung Cancer.

Kinase inhibitors (KI) have dramatically improved the outcome of treatment in patients with non-small cell lung cancer (NSCLC), which harbors an oncogene addiction. This study assesses KI plasma levels and their clinical relevance in patients chronically exposed to KIs. Plasma samples were collected in NSCLC patients receiving erlotinib, gefitinib, osimertinib, crizotinib, or dabrafenib (with or without trametinib) for at least three months between November 2013 and February 2019 in a single institution. KI drug concentrations were measured by ultra-performance liquid chromatography coupled with tandem mass spectrometry and compared to published data defining optimal plasma concentration. The main outcome was the rate of samples with suboptimal KI plasma concentrations. Secondary outcomes included its impact on T790M mutation emergence in patients receiving a first-generation epidermal growth factor receptor (EGFR) KI. Fifty-one samples were available from 41 patients with advanced NSCLC harboring driver genetic alterations, including EGFR, v-Raf murine sarcoma viral oncogene homolog B (BRAF), anaplastic lymphoma kinase (ALK) or ROS proto-oncogene 1 (ROS1), and who had an available evaluation of chronic KI plasma exposure. Suboptimal plasma concentrations were observed in 51% (26/51) of cases. In EGFR-mutant cases failing first-generation KIs, EGFR exon 20 p.T790M mutation emergence was detected in 31% (4/13) of samples in optimal vs. none in suboptimal concentration (0/5). Suboptimal plasma concentrations of KIs are frequent in advanced NSCLC patients treated with a KI for at least three months and might contribute to treatment failure.

Clinical Relevance of an Amplicon-Based Liquid Biopsy for Detecting ALK and ROS1 Fusion and Resistance Mutations in Patients With Non-Small-Cell Lung Cancer.

PURPOSE: Liquid biopsy specimen genomic profiling is integrated in non-small-cell lung cancer (NSCLC) guidelines; however, data on the clinical relevance for ALK /ROS1 alterations are scarce. We evaluated the clinical utility of a targeted amplicon-based assay in a large prospective cohort of patients with ALK/ROS1-positive NSCLC and its impact on outcomes. PATIENTS AND METHODS: Patients with advanced ALK/ROS1-positive NSCLC were prospectively enrolled in the study by researchers at eight French institutions. Plasma samples were analyzed using InVisionFirst-Lung and correlated with clinical outcomes. RESULTS: Of the 128 patients included in the study, 101 were positive for ALK and 27 for ROS1 alterations. Blood samples (N = 405) were collected from 29 patients naïve for treatment with tyrosine kinase inhibitors (TKI) or from 375 patients under treatment, including 105 samples collected at disease progression (PD). Sensitivity was 67% (n = 18 of 27) for ALK/ROS1 fusion detection. Higher detection was observed for ALK fusions at TKI failure (n = 33 of 74; 46%) versus in patients with therapeutic response (n = 12 of 109; 11%). ALK-resistance mutations were detected in 22% patients (n = 16 of 74) overall; 43% of the total ALK-resistance mutations identified occurred after next-generation TKI therapy. ALK G1202R was the most common mutation detected (n = 7 of 16). Heterogeneity of resistance was observed. ROS1 G2032R resistance was detected in 30% (n = 3 of 10). The absence of circulating tumor DNA mutations at TKI failure was associated with prolonged median overall survival (105.7 months). Complex ALK-resistance mutations correlated with poor overall survival (median, 26.9 months v NR for single mutation; P = .003) and progression-free survival to subsequent therapy (median 1.7 v 6.3 months; P = .003). CONCLUSION: Next-generation, targeted, amplicon-based sequencing for liquid biopsy specimen profiling provides clinically relevant detection of ALK/ROS1 fusions in TKI-naïve patients and allows for the identification of resistance mutations in patients treated with TKIs. Liquid biopsy specimens from patients treated with TKIs may affect clinical outcomes and capture heterogeneity of TKI resistance, supporting their role in selecting sequential therapy.

Circulating Tumor DNA Genomics Reveal Potential Mechanisms of Resistance to BRAF-Targeted Therapies in Patients with BRAF-Mutant Metastatic Non-Small Cell Lung Cancer.

PURPOSE: The limited knowledge on the molecular profile of patients with BRAF-mutant non-small cell lung cancer (NSCLC) who progress under BRAF-targeted therapies (BRAF-TT) has hampered the development of subsequent therapeutic strategies for these patients. Here, we evaluated the clinical utility of circulating tumor DNA (ctDNA)-targeted sequencing to identify canonical BRAF mutations and genomic alterations potentially related to resistance to BRAF-TT, in a large cohort of patients with BRAF-mutant NSCLC. EXPERIMENTAL DESIGN: This was a prospective study of 78 patients with advanced BRAF-mutant NSCLC, enrolled in 27 centers across France. Blood samples (n = 208) were collected from BRAF-TT-naïve patients (n = 47), patients nonprogressive under treatment (n = 115), or patients at disease progression (PD) to BRAF-TT (24/46 on BRAF monotherapy and 22/46 on BRAF/MEK combination therapy). ctDNA sequencing was performed using InVisionFirst-Lung. In silico structural modeling was used to predict the potential functional effect of the alterations found in ctDNA. RESULTS: BRAFV600E ctDNA was detected in 74% of BRAF-TT-naïve patients, where alterations in genes related with the MAPK and PI3K pathways, signal transducers, and protein kinases were identified in 29% of the samples. ctDNA positivity at the first radiographic evaluation under treatment, as well as BRAF-mutant ctDNA positivity at PD were associated with poor survival. Potential drivers of resistance to either BRAF-TT monotherapy or BRAF/MEK combination were identified in 46% of patients and these included activating mutations in effectors of the MAPK and PI3K pathways, as well as alterations in U2AF1, IDH1, and CTNNB1. CONCLUSIONS: ctDNA sequencing is clinically relevant for the detection of BRAF-activating mutations and the identification of alterations potentially related to resistance to BRAF-TT in BRAF-mutant NSCLC.

Outcomes in oncogenic-addicted advanced NSCLC patients with actionable mutations identified by liquid biopsy genomic profiling using a tagged amplicon-based NGS assay.

Circulating tumor DNA (ctDNA)-based molecular profiling is rapidly gaining traction in clinical practice of advanced cancer patients with multi-gene next-generation sequencing (NGS) panels. However, clinical outcomes remain poorly described and deserve further validation with personalized treatment of patients with genomic alterations detected in plasma ctDNA. Here, we describe the outcomes, disease control rate (DCR) at 3 months and progression-free survival (PFS) in oncogenic-addicted advanced NSCLC patients with actionable alterations identified in plasma by ctDNA liquid biopsy assay, InVisionFirst®-Lung. A pooled retrospective analysis was completed of 81 advanced NSCLC patients with all classes of alterations predicting response to current FDA approved drugs: sensitizing common EGFR mutations (78%, n = 63) with T790M (73%, 46/63), ALK / ROS1 gene fusions (17%, n = 14) and BRAF V600E mutations (5%, n = 4). Actionable driver alterations detected in liquid biopsy were confirmed by prior tissue genomic profiling in all patients, and all patients received personalized treatment. Of 82 patients treated with matched targeted therapies, 10% were at first-line, 41% at second-line, and 49% beyond second-line. Acquired T790M at TKI relapse was detected in 73% (46/63) of patients, and all prospective patients (34/46) initiated osimertinib treatment based on ctDNA results. The 3-month DCR was 86% in 81 evaluable patients. The median PFS was of 14.8 months (12.1-22.9m). Baseline ctDNA allelic fraction of genomic driver did not correlate with the response rate of personalized treatment (p = 0.29). ctDNA molecular profiling is an accurate and reliable tool for the detection of clinically relevant molecular alterations in advanced NSCLC patients. Clinical outcomes with targeted therapies endorse the use of liquid biopsy by amplicon-based NGS ctDNA analysis in first line and relapse testing for advanced NSCLC patients.

Oncogenic Fusions May Be Frequently Present at Resistance of EGFR Tyrosine Kinase Inhibitors in Patients With NSCLC: A Brief Report.

INTRODUCTION: Despite initial benefit, virtually all patients suffering from EGFR-mutant NSCLC experience acquired resistance to tyrosine kinase inhibitors (TKIs), driven by multiple mechanisms. Recent reports have identified oncogenic kinase fusions as off-target resistance mechanisms; however, these alterations have been rarely investigated at EGFR TKIs progression. METHODS: Patients with EGFR-mutated metastatic NSCLC (N = 62) with tissue and plasma biopsies at EGFR TKI progression between January 2015 and June 2019, at a French hospital and optionally before progression, were identified from the prospective MATCH-R study (NCT02517892). Postprogression biopsy samples were analyzed for gene fusions using targeted gene panel sequencing, whole-exome sequencing, RNA sequencing, and comparative genomic hybridization array. RESULTS: Six gene fusions were detected in tumor progression biopsies under an EGFR TKI from 62 consecutive patients (9.7%) with EGFR-mutated advanced NSCLC. Among 31 patients progressing to first- or second-generation EGFR TKIs, one (3%) had an Eukaryotic translation initiation factor 4 gamma 2-GRB2 associated binding protein 1 (EIF4G2-GAB1) fusion. Among 31 patients progressing to the third-generation osimertinib, five (16%) presented oncogene fusions of fibroblast growth factor receptor 3-transforming acidic coiled-coil containing protein 3 (FGFR3-TACC3) (n = 2), kinesin family member 5B-Ret proto-oncogene (KIF5B-RET) (n = 1), striatin-anaplastic lymphoma kinase (STRN-ALK) (n = 1), and zinc finger DHHC-Type palmitoyltransferase 20-Thr790Met (ZDHHC20-BRAF) (n = 1) transcripts. Out of two patients that received osimertinib at first-line, one acquired an FGFR3-TACC3 fusion at progression. In all patients, fusions co-occurred with the original activating EGFR mutation; however, among four patients with an acquired T790M mutation, three (75%) lost the T790M mutation. CONCLUSIONS: Oncogenic fusions at the time of EGFR TKI resistance were identified at a relatively high frequency, mainly after the third-generation TKI osimertinib. Patients progressing to EGFR TKIs may have a new opportunity for targeted therapy when oncogenic fusions are identified.

Circulating Tumor DNA Analysis for Patients with Oncogene-Addicted NSCLC With Isolated Central Nervous System Progression.

INTRODUCTION: In patients with oncogene-addicted NSCLC and isolated central nervous system progression (iCNS), tissue biopsy is challenging, and the clinical utility of plasma liquid biopsy (i.e., circulating tumor DNA [ctDNA]) is unknown. METHODS: Patients with advanced NSCLC with known baseline genomic alteration (GA) (EGFR, ALK, BRAF, KRAS, HER2, ROS1, MET, PIK3CA, STK11, TP53) on tissue were divided into three groups on the basis of their disease progression pattern: iCNS, extra-CNS only (noCNS), or both (cCNS). All patients with available plasma ctDNA were included and were analyzed by next-generation sequencing InVisionFirst-Lung. ctDNA was considered positive if at least one GA was detected. Cell-free tumor DNA was analyzed in cerebrospinal fluid when available. RESULTS: Out of 517 patients screened, 247 were included: 54 had iCNS, 99 had noCNS, and 94 had cCNS progressive disease (64, 128, and 110 ctDNA samples, respectively). CtDNA was positive in 52% iCNS versus 84% in noCNS and 92% in cCNS (p < 0.00001), with lower detection of driver (37% versus 77% and 73%, respectively) and resistance alterations (6% versus 45% and 44%). Patients with iCNS and positive ctDNA were more at risk of extra-CNS progression (32% versus 7%, p = 0.026). In 12 patients with iCNS, ctDNA was positive in six (50%) plasma and in 10 (83%) paired cerebrospinal fluid (p = 0.193). CONCLUSIONS: Although tagged amplicon-based next-generation sequencing has high detection rates of GA in plasma ctDNA in patients with NSCLC with extra-CNS disease, detection rate of GAs (52%) is lower in the subset of patients with iCNS disease. Complementary tests such as cerebrospinal fluid cell-free DNA may be useful. Further evidence would be beneficial to understand the genomic landscape in patients with NSCLC and iCNS.

Correction: EGFR C797S, EGFR T790M and EGFR sensitizing mutations in non-small cell lung cancer revealed by six-color crystal digital PCR.

[This corrects the article DOI: 10.18632/oncotarget.26446.].

Real-World Utility of an Amplicon-Based Next-Generation Sequencing Liquid Biopsy for Broad Molecular Profiling in Patients With Advanced Non-Small-Cell Lung Cancer.

PURPOSE: To assess the feasibility and utility of circulating tumor DNA (ctDNA) by amplicon-based next-generation sequencing (NGS) analysis in the daily clinical setting in a cohort of patients with advanced non-small-cell lung cancer (NSCLC), as an alternative approach to tissue molecular profiling. PATIENTS AND METHODS: In this single-center prospective study, treatment-naïve and previously treated patients with advanced NSCLC were enrolled. Clinical validation of ctDNA using amplicon-based NGS analysis (with a 36-gene panel) was performed against standard-of-care tissue molecular analysis in treatment-naïve patients. The feasibility, utility, and prognostic value of ctDNA as a dynamic marker of treatment efficacy was evaluated. Results of tissue molecular profile were blinded during ctDNA analysis. RESULTS: Of 214 patients with advanced NSCLC who were recruited, 156 were treatment-naïve patients and 58 were pretreated patients with unknown tissue molecular profile. ctDNA screening was successfully performed for 91% (n = 194) of all patients, and mutations were detected in 77% of these patients. Tissue molecular analysis was available for 111 patients (52%), and tissue somatic mutations were found for 78% (n = 87) of patients. For clinically relevant variants, concordance agreement between ctDNA and tumor tissue analysis was 95% among 94 treatment-naïve patients who had concurrent liquid and tumor biopsy molecular profiles. Sensitivity and specificity were 81% and 97%, respectively. Of the 103 patients with no tissue available, ctDNA detected potential actionable mutations in 17% of patients; of these, 10% received personalized treatment. ctDNA kinetics correlated with response rate and progression-free survival in 31 patients treated with first-line platinum-based chemotherapy. CONCLUSION: These real-world data from a prospective study endorse ctDNA molecular profile by amplicon-based NGS as an accurate and reliable tool to detect and monitor clinically relevant molecular alterations in patients with advanced NSCLC.

[Development of digital PCR molecular tests for clinical practice: principles, practical implementation and recommendations]. / Développement des analyses moléculaires par PCR digitale pour la pratique clinique : principes, mise en œuvre pratique et recommandations.

Digital PCR (dPCR) is a 3rd generation technology that complements traditional end-point PCR and real-time PCR. It was developed to overcome certain limitations of conventional amplification techniques, in particular for the detection of small amounts of nucleic acids and/or rare variants. This technology is in a full swing because of its high sensitivity and major applications in various domains such as oncology, transplantation or non-invasive prenatal testing. Consequently, PCRd also has great interest in many areas of medical biology, particularly for clinical applications aiming at detecting and quantifying specific genetic or epigenetic alterations of nucleic acids, even with specimens containing very low concentration of the nucleic acids of interest (e.g. liquid biopsies). However, this technique requires a good training of users and compliance with certain precautions. A lack in such a knowledge can lead to many errors in the conduct of the experiment and the interpretation of the results. In this review, we present the context in which this technology has emerged by describing in particular its principle and the main factors that can influence the quality of the analysis. Then, we propose a number of practical recommendations for the implementation of a test based on dPCR in clinical laboratories with an eye on quality requirements.

EGFR C797S, EGFR T790M and EGFR sensitizing mutations in non-small cell lung cancer revealed by six-color crystal digital PCR.

Background: Detection of EGFR sensitizing and p.T790M and p.C797S resistance mutations is particularly important for non-small cell lung cancer (NSCLC) patient therapy management. Non-invasive blood-based monitoring of these mutations may pave the way to a fine-tuned personalized treatment. Digital PCR has emerged as an extremely sensitive method to detect rare mutations, however its major limitation is the number of hotspots that can be simultaneously differentiated. Methods: We developed a 6-color digital PCR assay for the detection and quantification of 19 most prevalent EGFR sensitizing and resistance mutations and evaluated this assay on 82 tumor and plasma samples from NSLC patients. Results: Limits of detection (LOD) for the 6-color digital PCR assay were assessed on serial dilutions of DNA standards. We found that the 6-color assay enabled detection of mutant fractions as low as 1 mutant in 1025 wild-type molecules, depending on the mutation targeted, when assayed in a background of 10 000 wild-type DNA copies. EGFR mutant allelic fraction was also measured on tumor and plasma samples by 6-color digital PCR, and displayed a highly significant correlation with next generation sequencing and 3-color digital PCR. Lastly, the 6-color digital PCR assay was performed on several longitudinal plasma samples from four patients and revealed levels of sensitizing and resistance EGFR mutations that reflected well the course of the disease. Conclusion: This 6-color Crystal digital PCR assay could represent a robust solution using digital PCR for the monitoring of EGFR mutations.

Whole exome sequencing for determination of tumor mutation load in liquid biopsy from advanced cancer patients.

Tumor mutation load (TML) has been proposed as a biomarker of patient response to immunotherapy in several studies. TML is usually determined by tumor biopsy DNA (tDNA) whole exome sequencing (WES), therefore TML evaluation is limited by informative biopsy availability. Circulating cell free DNA (cfDNA) provided by liquid biopsy is a surrogate specimen to biopsy for molecular profiling. Nevertheless performing WES on DNA from plasma is technically challenging and the ability to determine tumor mutation load from liquid biopsies remains to be demonstrated. In the current study, WES was performed on cfDNA from 32 metastatic patients of various cancer types included into MOSCATO 01 (NCT01566019) and/or MATCHR (NCT02517892) molecular triage trials. Results from targeted gene sequencing (TGS) and WES performed on cfDNA were compared to results from tumor tissue biopsy. In cfDNA samples, WES mutation detection sensitivity was 92% compared to targeted sequencing (TGS). When comparing cfDNA-WES to tDNA-WES, mutation detection sensitivity was 53%, consistent with previously published prospective study comparing cfDNA-TGS to tDNA-TGS. For samples in which presence of tumor DNA was confirmed in cfDNA, tumor mutation load from liquid biopsy was correlated with tumor biopsy. Taken together, this study demonstrated that liquid biopsy may be applied to determine tumor mutation load. Qualification of liquid biopsy for interpretation is a crucial point to use cfDNA for mutational load estimation.

Crystal digital droplet PCR for detection and quantification of circulating EGFR sensitizing and resistance mutations in advanced non-small cell lung cancer.

Over the past years, targeted therapies using tyrosine kinase inhibitors (TKI) have led to an increase in progression-free survival and response rate for a subgroup of non-small cell lung cancer (NSCLC) patients harbouring specific gene abnormalities compared with chemotherapy. However long-lasting tumor regression is rarely achieved, due to the development of resistant tumoral subclones, which requires alternative therapeutic approaches. Molecular profile at progressive disease is a challenge for making adaptive treatment decisions. The aim of this study was to monitor EGFR-mutant tumors over time based on the quantity of mutant DNA circulating in plasma (ctDNA), comparing two different methods, Crystal™ Digital™ PCR and Massive Parallel Sequencing (MPS). In plasma circulating cell free DNA (cfDNA) of 61 advanced NSCLC patients we found an overall correlation of 78% between mutated allelic fraction measured by Crystal Digital PCR and MPS. 7 additional samples with sensitizing mutations and 4 additional samples with the resistance mutation were detected with Crystal Digital PCR, but not with MPS. Monitoring levels of both mutation types over time showed a correlation between levels and trends of mutated ctDNA detected and clinical assessment of disease for the 6 patients tested. In conclusion, Crystal Digital PCR exhibited good performance for monitoring mutational status in plasma cfDNA, and also appeared as better suited to the detection of known mutations than MPS in terms of features such as time to results.

Improving the Performance of Somatic Mutation Identification by Recovering Circulating Tumor DNA Mutations.

DNA extracted from cancer patients' whole blood may contain somatic mutations from circulating tumor DNA (ctDNA) fragments. In this study, we introduce cmDetect, a computational method for the systematic identification of ctDNA mutations using whole-exome sequencing of a cohort of tumor and corresponding peripheral whole-blood samples. Through the analysis of simulated data, we demonstrated an increase in sensitivity in calling somatic mutations by combining cmDetect to two widely used mutation callers. In a cohort of 93 breast cancer metastatic patients, cmDetect identified ctDNA mutations in 54% of the patients and recovered somatic mutations in cancer genes EGFR, PIK3CA, and TP53 We further showed that cmDetect detected ctDNA in 89% of patients with confirmed mutated cell-free tumor DNA by plasma analyses (n = 9) within 46 pan-cancer patients. Our results prompt immediate consideration of the use of this method as an additional step in somatic mutation calling using whole-exome sequencing data with blood samples as controls. Cancer Res; 76(20); 5954-61. ©2016 AACR.

[Tyrosine kinase inhibitors and pregnancy: A risk to the fetus?]. / Inhibiteurs de tyrosine kinase et grossesse : quels risques pour le fœtus ?

The association of cancer and pregnancy is increasingly frequent. This is related, partially, to the increasingly belated age of pregnancy. The management of cancer in pregnancy is a complicated issue. The use of tyrosine kinase inhibitors (TKIs) during pregnancy remains rare and only few data are available concerning their transplacental passage. The aim of this work is to review the data described in the literature, in order to highlight the risks incurred by the fetus, associated with these TKIs' treatment. Up to 189 pregnancies of women treated with TKIs during part or throughout their pregnancy have been described. Clinical data are reassuring and would be in favor of taking the treatment in terms of the balance maternal profit versus fetal risk. These data must, nevertheless, be interpreted with caution.

Circulating Cell-Free Tumor DNA Analysis of 50 Genes by Next-Generation Sequencing in the Prospective MOSCATO Trial.

PURPOSE: Liquid biopsies based on circulating cell-free DNA (cfDNA) analysis are described as surrogate samples for molecular analysis. We evaluated the concordance between tumor DNA (tDNA) and cfDNA analysis on a large cohort of patients with advanced or metastatic solid tumor, eligible for phase I trial and with good performance status, enrolled in MOSCATO 01 trial (clinical trial NCT01566019). EXPERIMENTAL DESIGN: Blood samples were collected at inclusion and cfDNA was extracted from plasma for 334 patients. Hotspot mutations were screened using next-generation sequencing for 50 cancer genes. RESULTS: Among the 283 patients with tDNA-cfDNA pairs, 121 had mutation in both, 99 in tumor only, 5 in cfDNA only, and for 58 patients no mutation was detected, leading to a 55.0% estimated sensitivity [95% confidence interval (CI), 48.4%-61.6%] at the patient level. Among the 220 patients with mutations in tDNA, the sensitivity of cfDNA analysis was significantly linked to the number of metastatic sites, albumin level, tumor type, and number of lines of treatment. A sensitivity prediction score could be derived from clinical parameters. Sensitivity is 83% in patients with a high score (≥8). In addition, we analyzed cfDNA for 51 patients without available tissue sample. Mutations were detected for 22 patients, including 19 oncogenic variants and 8 actionable mutations. CONCLUSIONS: Detection of somatic mutations in cfDNA is feasible for prescreening phase I candidates with a satisfactory specificity; overall sensitivity can be improved by a sensitivity score allowing to select patients for whom cfDNA constitutes a reliable noninvasive surrogate to screen mutations. Clin Cancer Res; 22(12); 2960-8. ©2016 AACR.