Circulating Tumor DNA-Guided De-Escalation Targeted Therapy for Advanced Non-Small Cell Lung Cancer: A Nonrandomized Controlled Trial.

Importance: Uninterrupted targeted therapy until disease progression or intolerable toxic effects is currently the routine therapy for advanced non-small cell lung cancer (NSCLC) involving driver gene variations. However, drug resistance is inevitable. Objective: To assess the clinical feasibility of adaptive de-escalation tyrosine kinase inhibitor (TKI) treatment guided by circulating tumor DNA (ctDNA) for achieving complete remission after local consolidative therapy (LCT) in patients with advanced NSCLC. Design, Setting, and Participants: This prospective nonrandomized controlled trial was conducted at a single center from June 3, 2020, to July 19, 2022, and included 60 patients with advanced NSCLC with driver variations without radiologically detectable disease after TKI and LCT. The median (range) follow-up time was 19.2 (3.8-29.7) months. Data analysis was conducted from December 15, 2022, to May 10, 2023. Intervention: Cessation of TKI treatment and follow-up every 3 months. Treatment was restarted in patients with progressive disease (defined by the Response Evaluation Criteria in Solid Tumors 1.1 criteria), detectable ctDNA, or elevated carcinoembryonic antigen (CEA) levels, whichever manifested first, and treatment ceased if all indicators were negative during follow-up surveillance. Main Outcomes and Measures: Progression-free survival (PFS). Secondary end points were objective response rate, time to next treatment, and overall survival. Results: Among the total study sample of 60 participants (median [range] age, 55 [21-75] years; 33 [55%] were female), the median PFS was 18.4 (95% CI, 12.6-24.2) months and the median (range) total treatment break duration was 9.1 (1.5-28.1) months. Fourteen patients (group A) remained in TKI cessation with a median (range) treatment break duration of 20.3 (6.8-28.1) months; 31 patients (group B) received retreatment owing to detectable ctDNA and/or CEA and had a median PFS of 20.2 (95% CI, 12.9-27.4) months with a median (range) total treatment break duration of 8.8 (1.5-20.6) months; and 15 patients (group C) who underwent retreatment with TKIs due to progressive disease had a median PFS of 5.5 (95% CI, 1.5-7.2) months. For all participants, the TKI retreatment response rate was 96%, the median time to next treatment was 29.3 (95% CI, 25.3-35.2) months, and the data for overall survival were immature. Conclusions and Relevance: The findings of this nonrandomized controlled trial suggest that this adaptive de-escalation TKI strategy for patients with NSCLC is feasible in those with no lesions after LCT and a negative ctDNA test result. This might provide a de-escalation treatment strategy guided by ctDNA for the subset of patients with advanced NSCLC. Trial Registration: ClinicalTrials.gov Identifier: NCT03046316.

Neoadjuvant sintilimab plus chemotherapy in EGFR-mutant NSCLC: Phase 2 trial interim results (NEOTIDE/CTONG2104).

The clinical efficacy of neoadjuvant immunotherapy plus chemotherapy remains elusive in localized epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer (NSCLC). Here, we report interim results of a Simon's two-stage design, phase 2 trial using neoadjuvant sintilimab with carboplatin and nab-paclitaxel in resectable EGFR-mutant NSCLC. All 18 patients undergo radical surgery, with one patient experiencing surgery delay. Fourteen patients exhibit confirmed radiological response, with 44% achieving major pathological response (MPR) and no pathological complete response (pCR). Similar genomic alterations are observed before and after treatment without influencing the efficacy of subsequent EGFR-tyrosine kinase inhibitors (TKIs) in vitro. Infiltration and T cell receptor (TCR) clonal expansion of CCR8+ regulatory T (Treg)hi/CXCL13+ exhausted T (Tex)lo cells define a subtype of EGFR-mutant NSCLC highly resistant to immunotherapy, with the phenotype potentially serving as a promising signature to predict immunotherapy efficacy. Informed circulating tumor DNA (ctDNA) detection in EGFR-mutant NSCLC could help identify patients nonresponsive to neoadjuvant immunochemotherapy. These findings provide supportive data for the utilization of neoadjuvant immunochemotherapy and insight into immune resistance in EGFR-mutant NSCLC.

PD-L1 expression guidance on sintilimab versus pembrolizumab with or without platinum-doublet chemotherapy in untreated patients with advanced non-small cell lung cancer (CTONG1901): A phase 2, randomized, controlled trial.

No direct comparison has been performed between different programmed cell death-1 (PD-1) inhibitors for first-line treatment in patients with advanced non-small cell lung cancer (NSCLC). The feasibility of using PD-L1-expression-guided immunotherapy remains unknown. In this open-label, phase 2 study (NCT04252365), patients with advanced NSCLC without EGFR or ALK alterations were randomized (1:1) to receive sintilimab or pembrolizumab monotherapy (PD-L1 expression ≥ 50%), or sintilimab or pembrolizumab plus platinum-based chemotherapy (PD-L1 expression < 50%). The sample size was calculated by optimal two-stage design. The primary endpoint was the objective response rate (ORR). The study included 71 patients (sintilimab arms, n = 35; pembrolizumab arms, n = 36) and met its primary endpoint, with a confirmed ORR of 51.4% (18/35) in the sintilimab arms. The confirmed ORR (95% confidence interval) was 46.2% (19.2%, 74.9%) and 42.9% (17.7%, 71.1%) for patients treated with sintilimab and pembrolizumab monotherapy; and 54.5% (32.2%, 75.6%) and 45.4% (24.4%, 67.8%) for those treated with sintilimab- and pembrolizumab-based combination therapies. The median progression-free survival was 6.9 versus 8.1 months for all sintilimab-treated versus all pembrolizumab-treated patients, respectively, in which it was 7.6 versus 11.0 months in monotherapy and 7.4 versus 7.1 months in combination therapies. The median overall survival was 14.9 versus 21.3 months for all sintilimab-treated versus all pembrolizumab-treated patients, respectively, in which it was 14.9 versus 22.6 months in monotherapy and 14.7 versus 17.3 months in combination therapies. Treatment-related adverse events were consistent with safety outcomes of monotherapy and combination therapy in previous phase III studies. However, the incidence of rash was higher with sintilimab than pembrolizumab monotherapy. This is the first prospective phase 2 study to directly compare two anti-PD-1 antibodies as first-line treatment in advanced NSCLC. Sintilimab was efficacious and well-tolerated irrespective of PD-L1 expression level in patients with advanced NSCLC and had similar efficacy and safety to pembrolizumab.

Efficacy, safety and dose selection of AZD3759 in patients with untreated EGFR-mutated non-small-cell lung cancer and central nervous system metastases in China (CTONG1702-Arm 8): a multi-center, single-arm, phase 2 trial.

Background: Central nervous system (CNS) metastases is inevitable for epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer (NSCLC). AZD3759 is a novel EGFR-TKI with impressive CNS penetration. Methods: We initiated a phase 2, multi-center, umbrella trial (CTONG1702, NCT03574402). The eighth arm assessed the efficacy and safety of AZD3759 in untreated EGFR-mutated NSCLC with CNS metastases. The primary objective was the objective response rate (ORR). Simon's minimax two-stage design was used to calculate the sample size. Dose optimal selection was performed using 200- and 300-mg bid cohorts. Findings: Between Oct 18, 2018 and Sep 14, 2020, 30 patients received AZD3759 at 200 mg (n = 15) or 300 mg (n = 15) bid. At data cutoff (Dec 31, 2022), median follow-up was 35.4 months. The primary endpoint was reached, with a confirmed ORR of 70% (21/30) (200 mg, 80%; 300 mg, 60%). The median progression-free survival was 12.9 months (200 mg, 15.8 months; 300 mg, 10.7 months). Grade 3 or 4 treatment-related adverse events occurred in 73% (22/30) of the patients (200 mg: 60%; 300 mg: 87%). 59% (10/17) of the patients developed a T790M mutation at disease progression. The median overall survival was 33.7 months, and 34.1 months and 25.3 months in patient treated with or without osimertinib in a later-line setting, respectively. Interpretation: AZD3759 showed promising efficacy and tolerable safety as a first-line therapy in EGFR-mutated NSCLC with CNS metastases. The 200-mg bid cohort had better clinical outcomes. Sequential use of AZD3759 and third-generation EGFR-TKIs represents a new option. Funding: Chinese Thoracic Oncology Group (CTONG).

Novel systemic therapies in the management of tyrosine kinase inhibitor-pretreated patients with epidermal growth factor receptor-mutant non-small-cell lung cancer.

Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) are the standard first-line option for non-small-cell lung cancer (NSCLC) harboring active EGFR mutations. The overall survival of patients with advanced NSCLC has improved dramatically with the development of comprehensive genetic profiles and targeted therapies. However, resistance inevitably occurs, leading to disease progression after approximately 10-18 months of EGFR-TKI treatment. Platinum-based chemotherapy is the standard treatment for patients who have experienced disease progression while undergoing EGFR-TKI treatment, but its efficacy is limited. The management of extensively pretreated patients with EGFR-mutant NSCLC is becoming increasingly concerning. New agents have shown encouraging efficacy in clinical trials for this patient population, including fourth-generation EGFR-TKIs, EGFR-TKIs combined with counterpart targeted drugs, and novel agents such as antibody-drug conjugates. We review current efforts to manage extensively pretreated patients with EGFR-mutant NSCLC.

First-line pyrotinib in advanced HER2-mutant non-small-cell lung cancer: a patient-centric phase 2 trial.

To explore targeted treatment options in patients with non-small-cell lung cancer (NSCLC) with rare genetic mutations in the context of a patient-centric clinical trial, we initiated, in parallel, a phase 2 adaptive umbrella trial consisting of a criteria-fulfilled (CF) cohort and a compassionate use (CU) cohort under expanded eligibility criteria, and a prospective real-world study (RWS). Here, we present efficacy and safety data from 48 patients with treatment-naive, advanced HER2-mutant NSCLC treated with the pan-HER receptor tyrosine kinase inhibitor pyrotinib (CF and CU cohorts) or physician's therapy of choice (RWS cohort). In the phase 2 trial CF cohort (n = 28), the primary endpoint was reached with an objective response rate of 35.7% after pyrotinib treatment. Secondary endpoints included disease control rate (89.3%), median progression-free survival (PFS) (7.3 months), median overall survival (OS) (14.3 months) and toxicity, which was acceptable, with grade 3 or 4 treatment-related adverse events occurring in three patients (10.7%). The phase 2 trial CU cohort (n = 12) showed an objective response rate of 16.7%, disease control rate of 83.4%, median PFS of 4.7 months and median OS of 14.2 months after pyrotinib treatment. The RWS cohort (n = 8) had no responses to physician's therapy of choice, while median PFS and OS were 3.0 and 12.2 months, respectively. Phase 2 umbrella trial, clinicaltrials.gov identifier: NCT03574402 . RWS, clinicaltrials.gov identifier: NCT03605602 .

Genomic and immune characteristics of HER2-mutated non-small-cell lung cancer and response to immune checkpoint inhibitor-based therapy.

The efficacy of immunotherapy in advanced HER2-mutated non-small-cell lung cancer (NSCLC) remains incomprehensively studied. A total of 107 NSCLC patients with de novo HER2 mutations were retrospectively studied at Guangdong Lung Cancer Institute [GLCI cohort, exon 20 insertions (ex20ins): 71.0%] to compare clinical/molecular features and immune checkpoint inhibitor (ICI)-based therapy efficacy between patients with ex20ins and non-ex20ins. Two external cohorts (TCGA, n = 21; META-ICI, n = 30) were used for validation. In the GLCI cohort, 68.2% of patients displayed programmed death-ligand 1 (PD-L1) expression < 1%. Compared with ex20ins patients, non-ex20ins patients had more concurrent mutations in the GLCI cohort (P < 0.01) and a higher tumour mutation burden in the TCGA cohort (P = 0.03). Under ICI-based therapy, advanced NSCLC patients with non-ex20ins had potentially superior progression-free survival [median: 13.0 vs. 3.6 months, adjusted hazard ratio (HR): 0.31, 95% confidence interval (CI): 0.11-0.83] and overall survival (median: 27.5 vs. 8.1 months, adjusted HR: 0.39, 95% CI: 0.13-1.18) to ex20ins patients, consistent with findings in the META-ICI cohort. ICI-based therapy may serve as an option for advanced HER2-mutated NSCLC, with potentially better efficacy in non-ex20ins patients. Further investigations are warranted in clinical practice.

Subsequent treatments beyond progression on osimertinib in EGFR-mutated NSCLC and leptomeningeal metastases.

BACKGROUND: Despite the reported efficacy of osimertinib, central nervous system (CNS) progression is still frequent in EGFR-mutated NSCLC. This study aimed to reveal site-specific resistant mechanisms to osimertinib and investigate subsequent treatments for leptomeningeal metastases (LM). METHODS: EGFR-mutated NSCLC with LM who progressed on osimertinib were included. Molecular analysis of cerebrospinal fluid (CSF) at osimertinib progression was performed. Subsequent treatments of LM were collected and analyzed. RESULTS: A total of 246 patients were identified. Only those with LM as a progression site on osimertinib were included (n=81). In 58 CSF-plasma pairs, more alterations were uniquely detected in CSF (77%) than in plasma (7%). These mechanisms led to 22 patients receiving matched targeted therapy. Among them, 16 (72.7%) had a clinical response. The median overall survival was 7.2 months. For non-matched therapy (n=59), the osimertinib combination had a longer median overall survival than the regimen switch in CNS-only progression (15.3 vs. 7 months, p=0.03). Finally, serial monitoring by CSF revealed the potential evolution of LM. CONCLUSIONS: Private resistant mechanisms in CSF might match osimertinib-resistant LM for targeted therapy. Besides, continuing osimertinib with intensification strategy might prolong survival, especially for those with CNS-only progression. Prospective  exploration is needed.

Genetic Profiling of Cell-Free DNA From Pleural Effusion in Advanced Lung Cancer as a Surrogate for Tumor Tissue and Revealed Additional Clinical Actionable Targets.

BACKGROUND: Pleural effusion (PE) has been one of the promising sources of liquid biopsy in advanced lung cancer patients. However, its clinical utility is not widely accepted due to the lack of full estimation of its potential versus routine clinical samples. METHOD: A total of 164 advanced lung cancer patients were enrolled with 164 matched tumor tissue and PE-cfDNA, 153 accompanied plasma and 63 1PE-sDNA. RESULT: PE-cfDNA displayed significantly higher median mutant allele frequency and an overall mutation concordance rate of 65% to tissue, which was higher than PE-sDNA (43%) and plasma-cfDNA (43%). The discrepancies between PE-cfDNA and tumor tissue were high in several genes, including SMARCA4, PIK3CA, ERBB2, KM T2A, ALK and NF1. For clinically actionable mutations, the concordance rate between PE-cfDNA and tumor tissue is 87%. Eleven patients were identified with actionable mutations in PE-cfDNA and four patients benefited from PE-cfDNA-guided targeted. Meanwhile, PE-cfDNA recapitulated mutations of diverse tissue origins and provided more mutational information under the circumstance that tumor tissue or tumor tissue of different origins were unavailable. The combination of tumor tissue and PE-cfDNA profiling increased positive detection rates of patients compared to tumor tissue alone. Our finding highlighted the importance of PE-cfDNA in the optimal selection of patients for targeted therapy. CONCLUSION: The PE-cfDNA-based liquid biopsy displays better performance in the characterization of gene alterations than PE-sDNA and plasma-cfDNA. PE-cfDNA together with tumor tissue profiling optimizes comprehensively genomic profiling of lung cancer patients, which might be important for selecting patients for better treatment management.

Clinical outcomes of non-small cell lung cancer patients with leptomeningeal metastases after immune checkpoint inhibitor treatments.

OBJECTIVE: Leptomeningeal metastases (LM) occur in up to 5% of non-small cell lung cancer (NSCLC) patients and often develop after previous systemic treatments. In this article, we explored whether immune checkpoint inhibitors (ICIs) enhanced the dismal survival of patients with LM. MATERIALS AND METHODS: Data on NSCLC patients with LM prescribed ICIs were collected at the Guangdong Lung Cancer Institute. Furthermore, relevant literature was reviewed. RESULTS: A total of 255 NSCLC patients diagnosed with LM were screened from January 2015 to March 2020 at our institute. Cases reported by literature were also included. Finally, 32 NSCLC patients received ICIs after LM diagnosis; their median age was 55 years. Druggable genes were detected in 37.5% of all patients. The ICI regimens included nivolumab (n = 21), pembrolizumab (n = 9), and atezolizumab (n = 2). Ultimately, 62.5% of patients evidenced neurological symptom controlled. Two patients exhibited both intracranial and extracranial complete tumour response; one patient showed both intracranial and extracranial partial response (PR), one patient indicated intracranial PR and a systemic PR, and one patient showed central nervous system PR without extracranial response reported. The median progression-free survival (PFS) in the single-agent subgroup was 2.1 months (95% confidence interval [CI]: 1.4-2.9 months), and the median overall survival (OS) was 4.0 months (95% CI: 0.1-13.3 months). In the combined subgroup, the median PFS and OS were 3.0 months (95% CI: 1.1-4.9 months) and 5.4 months (95% CI: 0.5-10.3 months), respectively. Three patients exhibited remarkable PFS of over 20 months: all patients had ICI single agent, received cranial radiotherapy before ICI prescription, and took ICIs as second-line therapy, and two patients were EGFR/ALK wild type. Multivariate analysis showed that a better Eastern Cooperative Oncology Group Performance Status (ECOG-PS) score was associated with prolonged PFS (P = 0.04). No difference in survival was seen between monotherapy and combination therapy groups. CONCLUSION: NSCLC patients with LM may benefit from ICIs of both monotherapy and combination with other therapies, especially those with good ECOG-PS scores. Further work in this regard is required.

Genotyping of Cerebrospinal Fluid Associated With Osimertinib Response and Resistance for Leptomeningeal Metastases in EGFR-Mutated NSCLC.

INTRODUCTION: Patients with NSCLC with leptomeningeal metastases (LM) presented dismal prognosis. Cerebrospinal fluid (CSF) is suggested as a medium of liquid biopsy of LM. However, the clinical implications of CSF genotyping on treatment outcomes remained elusive. METHODS: Patients with EGFR-mutated advanced NSCLC with LM were included: cohort 1, patients with LM who were treated with osimertinib with CSF and plasma genotyping performed before the first dosing of osimertinib (baseline, n = 45); cohort 2, CSF genotyping on progression on osimertinib and development of LM (the progression event on osimertinib is the diagnosis of LM, n = 35). Circulating tumor DNA in CSF underwent next-generation sequencing. RESULTS: Sensitivity of CSF genotyping for EGFR-sensitizing mutations was 93.3% (42 of 45) and 97.1% (34 of 35) in cohorts 1 and 2, respectively. In cohort 1, patients with EGFR exon 19 deletion had higher median intracranial progression free survival (iPFS) than those with EGFR exon 21 L858R mutation (11.9 versus 2.8 mo; p = 0.02). Median iPFS was significantly longer in patients with T790M-positive CSF genotyping (15.6 mo) than T790M-negative CSF (7.0 mo, p = 0.04). Concurrent CDK4 (2.8 versus 11.6 mo, p = 0.002) and CDKN2A (2.5 versus 9.6 mo, p = 0.04) mutation with EGFR-sensitizing mutations indicated lower median iPFS. Patients with T790M-negative CSF, EGFR exon 21 L858R mutation, concurrent FGF3 alteration, and over first-line osimertinib had shortened iPFS. In cohort 2, possible EGFR-related and EGFR-independent resistance mechanisms were found including C797S mutation, MET dysregulation, and TP53 plus RB1 co-occurrence. Patients with loss of T790M in CSF had a shorter median iPFS (7.4 mo) compared with those with reserved T790M (13.6 mo, p = 0.01). CONCLUSIONS: Genotyping of CSF indicated heterogeneous response to osimertinib and revealed the genetic characteristic of LM on osimertinib failure in patients with EGFR-mutated NSCLC diagnosed with LM.

Association of Cerebrospinal Fluid Tumor DNA Genotyping With Survival Among Patients With Lung Adenocarcinoma and Central Nervous System Metastases.

Importance: Owing to the improvement of systemic therapies for lung cancer, patients live longer, but the incidence of central nervous system (CNS) metastases also increases. Cerebrospinal fluid (CSF) has been proven better than plasma to reveal unique genetic profiling of intracranial metastases. How genetic alterations in CSF are associated with the prognosis of this heterogeneous patient group remains elusive. Objective: To examine the association of molecular alterations in CSF with the survival of patients with a diagnosis of lung adenocarcinoma and CNS metastases. Design, Setting, and Participants: This retrospective cohort analysis of 94 patients with advanced lung adenocarcinoma and CNS metastases was conducted from July 1, 2016, to July 31, 2018. Patients' CSF samples were collected, and next-generation sequencing of CSF circulating tumor DNA was performed. Main Outcome and Measures: The main outcome was survival after diagnosis with CNS metastases. Genotyping of CSF circulating tumor DNA was studied to examine its association with the clinical outcomes of patients with CNS metastases. Results: Of the 94 patients (49 male; mean [SD] age, 53 [1] years) with lung adenocarcinoma and CNS metastases evaluated, 79 harbored an EGFR variant. The most common genes seen in CSF were EGFR (79 [84.0%]), TP53 (57 [60.6%]), MET (23 [24.5%]), CDKN2A (22 [23.4%]), MYC (20 [21.3%]), NTRK1 (19 [20.2%]), and CDK6 (15 [16.0%]). Cluster analysis identified 5 molecular subtypes of CNS metastases. Patients in cluster I had the shortest median survival after diagnosis of CNS metastases compared with each of the other clusters (cluster I, 7.5 months; cluster II, 55.7 months; cluster III, 17.9 months; cluster IV, 27.9 months; cluster V, 21.0 months) and significantly increased risk of death compared with patients in the other clusters (cluster II: hazard ratio [HR], 4.95; 95% CI, 1.50-16.41; P = .009; cluster III: HR, 4.75; 95% CI, 1.49-15.12; P = .008; cluster IV: HR, 6.38; 95% CI, 1.76-23.09; P = .005; cluster V: HR, 5.42; 95% CI, 1.63-17.98; P = .006). The genetic profiles of cluster I were characterized by a high detection rate of CDK4 (9 of 9 [100%]), TP53 (8 of 9 [88.9%]), MET (7 of 9 [77.8%]), and CDKN2A (7 of 9 [77.8%]). For those with EGFR variants, coalterations with CDK4 (HR, 2.02; 95% CI, 1.03-3.96; P = .04), CDK6 (HR, 2.52; 95% CI, 1.32-4.83; P = .005), and MYC (HR, 2.24; 95% CI, 1.21-4.15; P = .01) were associated with poor outcomes. Conclusions and Relevance: Patients with a diagnosis of lung adenocarcinoma and CNS metastases experienced heterogeneous survival outcomes based on genetic profiling in CSF. These data suggest that CSF might facilitate risk stratifying CNS metastases into appropriate outcomes and provide reference for further clinical study.

A molecular graded prognostic assessment (molGPA) model specific for estimating survival in lung cancer patients with leptomeningeal metastases.

OBJECTIVES: Leptomeningeal metastases (LM) had increased in advanced non-small-cell lung cancer (NSCLC) over the last 10 years. The survival outcome remained overall poor, heterogeneous and was reported in association with genotypes in lung cancer patients with LM. Graded prognostic assessment model integrated with molecular alterations (molGPA) might be accurate for outcome prediction of LM patients, but needs to be established. MATERIALS AND METHODS: We retrospectively screened 8921 consecutive lung cancer patients from January 2011 to March 2018. A total of 301 patients diagnosed as LM were enrolled, and randomly divided into training and validation sets after stratified by gender and age. A molGPA score for each patient was calculated based on the weighted significant parameters including gene mutations. RESULT: The median OS for the 301 patients was 9.2 months (95%CI: 7.9-10.5). In the training set, EGFR/ALK positivity, Karnofsky performance score (KPS) score≥60 and absence of extracranial metastasis (ECM) independently predicted better OS. We developed a molGPA model based on above significant prognostic factors. This molGPA model classified LM patients into three prognosis groups of high, intermediate and low risk (molGPA score of 0, 0.5-1.0 and 1.5-2.0, respectively. The median OS of high, intermediate and low risk LM patients in the training set was 0.3, 3.5 and 15.9 months, respectively (p < 0.001). In the validation set, the median OS was 0.9, 5.8 and 17.7 months in the three molGPA subgroups, accordingly (p < 0.001). The C-index of this model in training and validation sets was 0.70 (95%CI: 0.66-0.73) and 0.64 (95%CI: 0.58-0.70) respectively. CONCLUSION: The LM molGPA model with integration of gene status, KPS and ECM can accurately classify lung cancer patients with LM into diverse prognosis.

Clinical Utility of Cerebrospinal Fluid Cell-Free DNA as Liquid Biopsy for Leptomeningeal Metastases in ALK-Rearranged NSCLC.

INTRODUCTION: Leptomeningeal metastases (LMs) indicated a poor prognosis in NSCLC. LMs were more frequent in driver gene-mutated patients, and cerebrospinal fluid (CSF) cell-free DNA has shown unique genetic profiles of LM in EGFR-mutated LM. However, studies in patients with ALK receptor tyrosine kinase gene (ALK)-rearranged NSCLC with LMs are scarce. METHODS: Patients with lung cancer with ALK rearrangement were screened from September 2011 to February 2018 at our institute. CSF and paired plasma were tested by next-generation sequencing. RESULTS: LMs were diagnosed in 30 (10.3%) of 291 patients with ALK-rearranged lung cancer. A total of 11 paired CSF and plasma samples tested by next-generation sequencing were analyzed. Driver genes were detected in 81.8% of the CSF samples (9 of 11) and 45.5% of the plasma samples (5 of 11) (p = 0.183). The maximum allelic fractions were all higher in CSF than in plasma (p = 0.009). ALK and tumor protein p53 gene (TP53) were the two most frequently mutated genes in CSF. Gatekeeper gene ALK G1202R and C1156F mutations were identified in CSF after resistance to alectinib. Multiple copy number variants were mainly found in CSF, including in EGFR, cyclin D1 gene (CCND1), fibroblast growth factor 3 gene (FGF3), and fibroblast growth factor 4 gene (FGF4). Also found were v-myc avian myelocytomatosis viral oncogene homolog gene (MYC) copy number gains and TP53 and cyclin dependent kinase inhibitor 2A gene (CDKN2A) copy number deletions. Brigatinib seemed to be effective in controlling LM. One case showed that CSF could be used to monitor disease development of LM and longitudinally monitor tumor response. CONCLUSION: Liquid biopsy of CSF is more sensitive than liquid biopsy of plasma to detect targetable alterations, characterizing resistance mechanisms on progression and monitoring tumor response in patients with ALK-rearranged NSCLC with LM. Thus, CSF might be promising as a medium of liquid biopsy in LM.

Detection of Driver and Resistance Mutations in Leptomeningeal Metastases of NSCLC by Next-Generation Sequencing of Cerebrospinal Fluid Circulating Tumor Cells.

Purpose: Leptomeningeal metastases are more common in non-small cell lung cancer (NSCLC) with EGFR mutations. The diagnosis is difficult by traditional imaging only, and leads to poor understanding of resistance mechanisms of leptomeningeal metastases.Experimental Design: We compared the CellSearch Assay, the Thinprep cytologic test (TCT), and brain magnetic resonance imaging (MRI) in 21 NSCLC patients with suspected leptomeningeal metastases. Next-generation sequencing that included 416 cancer-associated genes was also performed on cerebrospinal fluid circulating tumor cells (CSFCTC) of 19 patients.Results: Twenty-one patients were diagnosed with leptomeningeal metastases, and CSFCTCs were captured by CellSearch in 20 patients (median, 969 CSFCTCs/7.5 mL; range, 27-14,888). CellSearch had a sensitivity of 95.2% for leptomeningeal metastases diagnosis, which was higher than that of TCT (12/21, 57.1%), MRI (10/21, 47.6%), and MRI plus TCT (19/21, 90.5%), respectively. CTCs were found only in 5 of 14 patients (median, 2 CTCs/7.5 mL; range, 2-4), which was a much lower ratio than CSFCTCs. Genetic profiles of CSFCTCs were highly concordant with molecular mutations identified in the primary tumor (17/19, 89.5%). The resistance gene EGFR T790M was detected in 7 of 9 patients with extracranial lesions, but was detected in only 1 of 14 CSFCTC samples. Other potential resistant mutations, such as MET amplification and ERBB2 mutation, were also identified in CSFCTCs.Conclusions: CSFCTCs captured by CellSearch may be a more sensitive and effective way to diagnose leptomeningeal metastases, and may serve as a liquid biopsy medium for gene profiles in NSCLC patients with leptomeningeal metastases. Clin Cancer Res; 23(18); 5480-8. ©2017 AACR.

Mixed Responses to Systemic Therapy Revealed Potential Genetic Heterogeneity and Poor Survival in Patients with Non-Small Cell Lung Cancer.

BACKGROUND: A subset of patients with non-small cell lung cancer (NSCLC) fosters mixed responses (MRs) to epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs) or chemotherapy. However, little is known about the clinical and molecular features or the prognostic significance and potential mechanisms. METHODS: The records of 246 consecutive patients with NSCLC receiving single-line chemotherapy or TKI treatment and who were assessed by baseline and interim positron emission tomography/computed tomography scans were collected retrospectively. The clinicopathological correlations of the MR were analyzed, and a multivariate analysis was performed to explore the prognostic significance of MR. RESULTS: The overall incidence of MR to systemic therapy was 21.5% (53/246) and predominated in patients with stage IIIB-IV, EGFR mutations and those who received TKI therapy (p < .05). Subgroup analyses based on MR classification (efficacious versus inefficacious) showed significant differences in subsequent treatment between the two groups (p < .001) and preferable progression-free survival (PFS) and overall survival (OS) in the efficacious MR group. Multivariate analyses demonstrated that the presence of MR was an independent unfavorable prognostic factor for PFS (hazard ratio [HR], 1.474; 95% confidence interval [CI], 1.018-2.134; p = .040) and OS (HR, 1.849; 95% CI, 1.190-2.871; p = .006) in patients with NSCLC. Induced by former systemic therapy, there were more T790M (18%), concomitant EGFR mutations (15%), and changes to EGFR wild type (19%) in the MR group among patients with EGFR mutations, which indicated higher incidence of genetic heterogeneity. CONCLUSION: MR was not a rare event in patients with NSCLC and tended to occur in those with advanced lung adenocarcinoma treated with a TKI. MR may result from genetic heterogeneity and is an unfavorable prognostic factor for survival. Further studies are imperative to explore subsequent treatment strategies. The Oncologist 2017;22:61-69Implications for Practice: Tumor heterogeneity tends to produce mixed responses (MR) to systemic therapy, including TKI and chemotherapy; however, the clinical significance and potential mechanisms are not fully understood, and the subsequent treatment after MR is also a clinical concern. The present study systemically assessed patients by PET/CT and differentiated MR and therapies. The study identified a relatively high incidence of MR in patients with advanced NSCLC, particularly those treated with targeted therapies. An MR may be an unfavorable prognostic factor and originate from genetic heterogeneity. Further studies are imperative to explore subsequent treatment strategies.