Sequencing of cerebrospinal fluid in non-small-cell lung cancer patients with leptomeningeal metastasis: A systematic review

Leptomeningeal metastatic disease: new frontiers and future directions

Leptomeningeal metastatic disease (LMD), encompassing entities of 'meningeal carcinomatosis', neoplastic meningitis' and 'leukaemic/lymphomatous meningitis', arises secondary to the metastatic dissemination of cancer cells from extracranial and certain intracranial malignancies into the leptomeninges and cerebrospinal fluid. The clinical burden of LMD has been increasing secondary to more sensitive diagnostics, aggressive local therapies for discrete brain metastases, and improved management of extracranial disease with targeted and immunotherapeutic agents, resulting in improved survival. However, owing to drug delivery challenges and the unique microenvironment of LMD, novel therapies against systemic disease have not yet translated into improved outcomes for these patients. Underdiagnosis and misdiagnosis are common, response assessment remains challenging, and the prognosis associated with this disease of whole neuroaxis remains extremely poor. The dearth of effective therapies is further challenged by the difficulties in studying this dynamic disease state. In this Review, a multidisciplinary group of experts describe the emerging evidence and areas of active investigation in LMD and provide directed recommendations for future research. Drawing upon paradigm-changing advances in mechanistic science, computational approaches, and trial design, the authors discuss domain-specific and cross-disciplinary strategies for optimizing the clinical and translational research landscape for LMD. Advances in diagnostics, multi-agent intrathecal therapies, cell-based therapies, immunotherapies, proton craniospinal irradiation and ongoing clinical trials offer hope for improving outcomes for patients with LMD.

EML4-ALK: Update on ALK Inhibitors

Since the discovery of the first-generation ALK inhibitor, many other tyrosine kinase inhibitors have been demonstrated to be effective in the first line or further lines of treatment in patients with advanced non-small cell lung cancer with EMLA4-ALK translocation. This review traces the main milestones in the treatment of ALK-positive metastatic patients and the survival outcomes in the first-line and second-line settings with different ALK inhibitors. It presents the two options available for first-line treatment at the present time: sequencing different ALK inhibitors versus using the most potent inhibitor in front-line treatment. The efficacy outcomes of different ALK inhibitors in the first-line setting; the molecular profile of the disease, including mutation resistances and ALK variants and co-mutations; and patients' co-morbidities and inhibitor toxicities should be taken into account to address the choice of the first-line treatment, as suggested in this review.

Osimertinib-induced DNA resistance mutations in cerebrospinal fluid of epidermal growth factor receptor-mutated non-small-cell lung carcinoma patients developing leptomeningeal metastases: Osimertinib Resistance Analysis-leptomeningeal metastases study

BACKGROUND

Diagnosis and treatment of leptomeningeal metastases (LM) in epidermal growth factor receptor mutation-positive (EGFRm +) non-small-cell lung carcinoma (NSCLC) is challenging. We aimed to identify resistance mechanisms (RM) to osimertinib in cerebrospinal fluid (CSF) and plasma.

METHODS

EGFRm + patients with new or progressive LM during osimertinib were enrolled. NGS Ampliseq was performed on DNA isolated from CSF. Patients were prescribed osimertinib dose escalation (DE, 160 mg QD) following lumbar puncture. Clinical and radiological response was evaluated 4 weeks after osimertinib DE.

RESULTS

Twenty-eight patients were included. The driver mutation was identified in 93% of CSF samples (n = 26). Seven (27%) harbored ≥1 RM. Twenty-five patients (89%) were prescribed osimertinib DE. Four weeks afterwards, symptoms improved in 5 patients, stabilized in 9 and worsened in 11 patients. Twenty-one (84%) patients underwent MR imaging. Four showed radiological improvement, 14 stabilization, and 3 worsening.

CONCLUSIONS

In 27% of patients, an RM was found in CSF ctDNA, none of which are targetable at the time of writing, and the clinical efficacy of osimertinib DE seems limited. There is much to gain in diagnostic as well as therapeutic strategies in EGFRm + NSCLC LM.

Overview of the Role of Liquid Biopsy in Non-small Cell Lung Cancer (NSCLC)

Solid tumour tissue has traditionally been used for cancer molecular diagnostics. Recently, biomarker assessment in blood or liquid biopsies has become relevant because it allows genotyping in a less invasive and costly manner. In addition, it is a very useful technique in cases with insufficient tumour samples. Recent data have shown that this method can provide the baseline molecular characteristics of the tumour and resistance changes that emerge during cancer treatment. In terms of diagnostic application, the platforms available for clinical use in lung cancer focus on the isolation and detection of circulating DNA (ctDNA) and generally cover a limited number of mutations in genes such as epidermal growth factor receptor (EGFR), Kirsten rat sarcoma viral oncogene homolog (KRAS) and BRAF, as well as anaplastic lymphoma kinase (ALK) rearrangements. In parallel, there are plasma genotyping platforms based on next-generation sequencing (NGS) techniques, which are much broader in scope, allowing multiple genes to be studied simultaneously in a more efficient manner. More recently, promising research scenarios for liquid biopsy have emerged, such as its utility for early diagnosis and evaluation of minimal residual disease after oncological treatment. In light of these advances, knowledge of the benefits and limitations of liquid biopsy, as well as awareness of emerging information on new indications for this technique in non-small cell lung cancer (NSCLC), are of paramount importance in developing more effective management strategies for patients with this neoplasm.

Quantification of cerebrospinal fluid tumor DNA in lung cancer patients with suspected leptomeningeal carcinomatosis

Cerebrospinal fluid tumor-derived DNA (CSF-tDNA) analysis is a promising approach for monitoring the neoplastic processes of the central nervous system. We applied a lung cancer-specific sequencing panel (CAPP-Seq) to 81 CSF, blood, and tissue samples from 24 lung cancer patients who underwent lumbar puncture (LP) for suspected leptomeningeal disease (LMD). A subset of the cohort (N = 12) participated in a prospective trial of osimertinib for refractory LMD in which serial LPs were performed before and during treatment. CSF-tDNA variant allele fractions (VAFs) were significantly higher than plasma circulating tumor DNA (ctDNA) VAFs (median CSF-tDNA, 32.7%; median plasma ctDNA, 1.8%; P < 0.0001). Concentrations of tumor DNA in CSF and plasma were positively correlated (Spearman's ρ, 0.45; P = 0.03). For LMD diagnosis, cytology was 81.8% sensitive and CSF-tDNA was 91.7% sensitive. CSF-tDNA was also strongly prognostic for overall survival (HR = 7.1; P = 0.02). Among patients with progression on targeted therapy, resistance mutations, such as EGFR T790M and MET amplification, were common in peripheral blood but were rare in time-matched CSF, indicating differences in resistance mechanisms based on the anatomic compartment. In the osimertinib cohort, patients with CNS progression had increased CSF-tDNA VAFs at follow-up LP. Post-osimertinib CSF-tDNA VAF was strongly prognostic for CNS progression (HR = 6.2, P = 0.009). Detection of CSF-tDNA in lung cancer patients with suspected LMD is feasible and may have clinical utility. CSF-tDNA improves the sensitivity of LMD diagnosis, enables improved prognostication, and drives therapeutic strategies that account for spatial heterogeneity in resistance mechanisms.

[Advances in Clinical Application of Cerebrospinal Fluid Circulating Tumor DNA in Leptomeningeal Metastasis of Non-small Cell Lung Cancer]

Leptomeningeal metastasis (LM) is a lethal complication of malignant tumors, with an incidence rate of 3%-5% among patients with non-small cell lung cancer (NSCLC). LM poses significant challenges in diagnosis, has poor prognosis, limited treatment options, and lacks standardized criteria for evaluating therapeutic efficacy, making it a difficult aspect of NSCLC management. Circulating tumor DNA (ctDNA), shed from tumor cells and carrying cancer-related information, holds significant value in precision oncology. Cerebrospinal fluid (CSF), present in the subarachnoid space of the brain, the spinal cord, and the central canal, and in direct contact with meningeal tissues, serves as the fluid medium that best reflects the genetic characteristics of LM. In recent years, CSF ctDNA has become a focal point due to its multi-omics features, playing a crucial role in the management of central nervous system (CNS) metastatic tumors. Its applications span the entire continuum of care, including aiding in diagnosis, assessing treatment response, predicting prognosis, and analyzing resistance mechanisms. This article provides a concise overview of CSF ctDNA detection techniques and their clinical applications in patients with NSCLC-LM.
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Predictive value of pre-operative prognostic nutritional index and systemic immune-inflammation index for efficacy and survival in patients with non-small cell lung cancer undergoing neoadjuvant chemotherapy

OBJECTIVE

To explore the predictive value of preoperative prognostic nutritional index (PNI) and systemic immune inflammation index (SII) in relation to the efficacy and prognosis in patients with non-small cell lung cancer (NSCLC) undergoing neoadjuvant chemotherapy (NACT).

METHODS

Data of patients with stage IIIA-N2 NSCLC who received NACT in the 910th Hospital of Chinese People's Liberation Army from January 2017 to April 2020 were retrospectively analysed. Patients undergoing NACT were divided into the pCR group (80 cases with complete remission or partial remission) and the non-pCR group (46 cases with stable disease or progressive disease) in accordance with their treatment outcome. The pathologic and clinical data of the patients were collected and analysed to identify the factors affecting efficacy of NACT for stage IIIa-N2 NSCLC, and to evaluate the predictive value of PNI and SII in determining the efficacy of NACT. The patients were followed up for 3 years to observe the overall survival, and Cox regression analysis was employed to identify the risk factors affecting patient survival. Furthermore, the effect of PNI and SII on the survival time was analysed.

RESULTS

Multivariate regression analysis showed that tumor diameter, PNI, and SII were influencing factors for poor efficacy of NACT in patients with stage IIIa-N2 NSCLC. The non-pCR group exhibited a higher mortality within 3 years, thus a lower 3-year overall survival rate than the pCR group (P<0.05). Cox regression analysis revealed that both PNI and SII were risk factors for poor prognosis in patients with stage IIIa-N2 NSCLC undergoing NACT. Further analysis found a lower 3-year survival rate in patients with low PNI and high SII than in counterparts (P<0.05).

CONCLUSION

Tumor diameter, PNI and SII are risk factors for poor efficacy in patients with stage IIIa-N2 NSCLC undergoing NACT. Low PNI and high SII can indicate a poor prognosis in these patients.

Tissue or liquid rebiopsy? A prospective study for simultaneous tissue and liquid NGS after first-line EGFR inhibitor resistance in lung cancer

INTRODUCTION

According to current International Association for the Study of Lung Cancer guideline, physicians may first use plasma cell-free DNA (cfDNA) methods to identify epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI)-resistant mechanisms (liquid rebiopsy) for lung cancer. Tissue rebiopsy is recommended if the plasma result is negative. However, this approach has not been evaluated prospectively using next-generation sequencing (NGS).

METHODS

We prospectively enrolled patients with lung cancer with first-line EGFR-TKI resistance who underwent tissue rebiopsy. The rebiopsied tissues and cfDNA were sequenced using targeted NGS, ACTDrug®+, and ACTMonitor®Lung simultaneously. The clinicopathological characteristics and treatment outcomes were analyzed.

RESULTS

Totally, 86 patients were enrolled. Twenty-six (30%) underwent tissue biopsy but the specimens were inadequate for NGS. Among the 60 patients with paired tissue and liquid rebiopsies, two-thirds (40/60) may still be targetable. T790M mutations were found in 29, including 14 (48%) only from tissue and 5 (17%) only from cfDNA. Twenty-four of them were treated with osimertinib, and progression-free survival was longer in patients without detectable T790M in cfDNA than in patients with detectable T790M in cfDNA (p = 0.02). For the 31 T790M-negative patients, there were six with mesenchymal-epithelial transition factor (MET) amplifications, four with ERBB2 amplifications, and one with CCDC6-RET fusion. One with MET amplification and one with ERBB2 amplification responded to subsequent MET and ERBB2 targeting agents respectively.

CONCLUSIONS

NGS after EGFR-TKI resistance may detect targetable drivers besides T790M. To do either liquid or tissue NGS only could miss patients with T790M. To do tissue and liquid NGS in parallel after EGFR-TKI resistance may find more patients with targetable cancers.

The Riddle of the Sphinx: Progress in Leptomeningeal Metastasis of Non-Small Cell Lung Cancer

Leptomeningeal metastasis (LM) is a serious complication of advanced non-small cell lung cancer (NSCLC), and the incidence of LM has been increasing yearly in recent times. There is no consensus on the best treatment modality for LM, which underscores a difficult problem in the management of advanced NSCLC patients. The existing treatments include molecular targeted therapy, systemic chemotherapy, local radiotherapy, antivascular tumor therapy, intrathecal chemotherapy, and immunotherapy, but their efficacy is not satisfactory. In this article, we briefly describe the clinical manifestations, diagnosis, and treatment of NSCLC-LM and discuss progress regarding evaluation of the efficacy of LM treatment to better provide a necessary reference for clinical practice and clinical trial evaluation.

Cerebrospinal fluid circulating tumour DNA genotyping and survival analysis in lung adenocarcinoma with leptomeningeal metastases

PURPOSE

The prognosis of patients with leptomeningeal metastasis (LM) remains poor. Circulating tumour DNA (ctDNA) has been proven to be abundantly present in cerebrospinal fluid (CSF); hence, its clinical implication as a biomarker needs to be further verified.

METHODS

We conducted a retrospective study of 35 lung adenocarcinoma (LUAD) patients with LM, and matched CSF and plasma samples were collected from all patients. All paired samples underwent next-generation sequencing (NGS) of 139 lung cancer-associated genes. The clinical characteristics and genetic profiling of LM were analysed in association with survival prognosis.

RESULTS

LM showed genetic heterogeneity, in which CSF had a higher detection rate of ctDNA (P = 0.003), a higher median mutation count (P < 0.0001), a higher frequency of driver mutations (P < 0.01), and more copy number variation (CNV) alterations (P < 0.001) than plasma. The mutation frequencies of the EGFR, TP53, CDKN2A, MYC and CDKN2B genes were easier to detect in CSF than in LUAD tissue (P < 0.05), possibly reflecting the underlying mechanism of LM metastasis. CSF ctDNA is helpful for analysing the mechanism of EGFR-TKI resistance. In cohort 1, which comprised patients who received 1/2 EGFR-TKIs before the diagnosis of LM, TP53 and CDKN2A were the most common EGFR-independent resistant mutations. In cohort 2, comprising those who progressed after osimertinib and developed LM, 7 patients (43.75%) had EGFR CNV detected in CSF but not plasma. Furthermore, patient characteristics and various genes were included for interactive survival analysis. Patients with EGFR-mutated LUAD (P = 0.042) had a higher median OS, and CSF ctDNA mutation with TERT (P = 0.013) indicated a lower median OS. Last, we reported an LM case in which CSF ctDNA dynamic changes were well correlated with clinical treatment.

CONCLUSIONS

CSF ctDNA could provide a more comprehensive genetic landscape of LM, indicating the potential metastasis-related and EGFR-TKI resistance mechanisms of LM patients. In addition, genotyping of CSF combined with clinical outcomes can predict the prognosis of LUAD patients with LM.