Nasopharyngeal carcinoma with leptomeningeal metastases has been treated with comprehensive treatment for long-term survival: A case report and literature review.

RATIONALE: Nasopharyngeal carcinoma has a high incidence in East and Southeast Asia, often with distant metastasis. However, leptomeningeal metastasis (LM) is extremely rare and usually has a poor prognosis. This paper reports the clinical treatment of a patient with meningeal metastasis of nasopharyngeal carcinoma (NPC) in order to improve the clinician's understanding of the disease. Early diagnosis of the disease can alleviate the pain of patients and prolong their survival time. PATIENT CONCERNS: We report the case of a 55-year-old female with a history of NPC with LM. Brain magnetic resonance imaging showed temporal lobe enhancement, peripheral edema, and enhancement of the adjacent meninges. Cerebrospinal fluid cytology suggests the presence of malignant tumor cells. DIAGNOSES: The patient was diagnosed with LM from NPC. INTERVENTIONS: The patients were regularly given targeted therapy with nimotuzumab, immunotherapy with karyolizumab, and lumbar intrathecal methotrexate chemotherapy and supportive treatment. OUTCOMES: The patient had survived for 3 years since the diagnosis of LM and was in good condition and still under active antitumor treatment. LESSONS: Leptomeningeal metastasis of NPC is a rare disease. Although there is currently no unified treatment plan, the neurological symptoms can still be controlled and the quality of life can be improved through active treatment.

Patients with Leptomeningeal Carcinomatosis and Hydrocephalus-Feasibility of Combined Ventriculoperitoneal Shunt and Reservoir Insertion for Intrathecal Chemotherapy.

Therapeutic management of patients with leptomeningeal carcinomatosis (LC) may require treatment of concomitant hydrocephalus (HC) in addition to intrathecal chemotherapy (ITC). Ventriculoperitoneal shunts (VPS) equipped with a valve for manual deactivation of shunt function and a concomitant reservoir for application of ITC pose an elegant solution to both problems. The present study evaluates indication, feasibility, and safety of such a modified shunt/reservoir design (mS/R). All patients with LC aged ≥ 18 years who had undergone mS/R implantation between 2013 and 2020 at the authors' institution were further analyzed. ITC was indicated following the recommendation of the neuro-oncological tumor board and performed according to a standardized protocol. Sixteen patients with LC underwent mS/R implantation for subsequent ITC and concomitant treatment of HC. Regarding HC-related clinical symptoms, 69% of patients preoperatively exhibited lethargy, 38% cognitive impairment, and 38% (additional) visual disturbances. Postoperatively, 86% of patients achieved subjective improvement of HC-related symptoms. Overall, postoperative complications occurred in three patients (19%). No patient encountered cancer treatment-related complications. The present study describes a combination procedure consisting of a standard VPS-system and a standard reservoir for patients suffering from LC and HC. No cancer treatment-related complications occurred, indicating straightforward handling and thus safety.

Outcomes, responses, and prognostic analyses of intrathecal combined treatment for leptomeningeal metastasis from lung adenocarcinoma.

BACKGROUND: Leptomeningeal metastasis (LM) is a severe lung cancer complication, with potentially fatal consequences. The use of intrathecal therapy (IT) combined with systemic therapy has shown promise as a treatment approach for LM. Thus, this study aimed to evaluate the features and responses to IT combined therapy and identify determinants affecting patients with leptomeningeal metastasis resulting from lung adenocarcinoma (LM-LA). METHODS: A retrospective analysis of medical records from our hospital database was performed, covering from April 2018 to August 2022, for 37 patients diagnosed with LM-LA and treated with IT combined therapy. Patients who received IT combined therapy for LM-LA were evaluated for demographic characteristics, treatment efficacy, survival, and variables that impacted them. RESULTS: The median overall survival (mOS) of 37 patients was 16.0 months, and the survival rates at 6 and 12 months were 75.7% and 35.1%, respectively. Among the 21 patients with LM-LA who received IT combined with tyrosine kinase inhibitors (TKIs), the mOS was 17.0 months, which was significantly longer than that of patients treated with IT combined with chemotherapy (7.0 months, P = 0.010) and the best supportive care (6.0 months, P = 0.001). However, no significant survival benefit was observed in patients treated with IT combined with TKIs when compared with those treated with IT combined with PD-1 (5.0 months, P = 0.249). Multivariate analysis indicated that the combination of TKIs was an independent favorable prognostic factor for patients with LM-LA. CONCLUSION: Combination treatment is regarded as an additional option for patients with LM-LA. Compared with other combination therapies in our study, IT combined with TKI therapy provided a better survival outcome for patients with LM-LA.

PROTAC EZH2 degrader-1 overcomes the resistance of podophyllotoxin derivatives in refractory small cell lung cancer with leptomeningeal metastasis.

BACKGROUND: Leptomeningeal metastasis (LM) of small cell lung cancer (SCLC) is a highly detrimental occurrence associated with severe neurological disorders, lacking effective treatment currently. Proteolysis-targeting chimeric molecules (PROTACs) may provide new therapeutic avenues for treatment of podophyllotoxin derivatives-resistant SCLC with LM, warranting further exploration. METHODS: The SCLC cell line H128 expressing luciferase were mutated by MNNG to generate H128-Mut cell line. After subcutaneous inoculation of H128-Mut into nude mice, H128-LM and H128-BPM (brain parenchymal metastasis) cell lines were primarily cultured from LM and BPM tissues individually, and employed to in vitro drug testing. The SCLC-LM mouse model was established by inoculating H128-LM into nude mice via carotid artery and subjected to in vivo drug testing. RNA-seq and immunoblotting were conducted to uncover the molecular targets for LM. RESULTS: The SCLC-LM mouse model was successfully established, confirmed by in vivo live imaging and histological examination. The upregulated genes included EZH2, SLC44A4, VEGFA, etc. in both BPM and LM cells, while SLC44A4 was particularly upregulated in LM cells. When combined with PROTAC EZH2 degrader-1, the drug sensitivity of cisplatin, etoposide (VP16), and teniposide (VM26) for H128-LM was significantly increased in vitro. The in vivo drug trials with SCLC-LM mouse model demonstrated that PROTAC EZH2 degrader-1 plus VM26 or cisplatin/ VP16 inhibited H128-LM tumour significantly compared to VM26 or cisplatin/ VP16 alone (P < 0.01). CONCLUSION: The SCLC-LM model effectively simulates the pathophysiological process of SCLC metastasis to the leptomeninges. PROTAC EZH2 degrader-1 overcomes chemoresistance in SCLC, suggesting its potential therapeutic value for SCLC LM.

Furmonertinib and intrathecal pemetrexed chemotherapy rechallenges osimertinib-refractory leptomeningeal metastasis in a non-small cell lung cancer patient harboring EGFR20 R776S, C797S, and EGFR21 L858R compound EGFR mutations: a case report.

Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) are considered the first-line treatment for advanced or metastatic non-small cell lung cancer (NSCLC) patients harboring EGFR mutations. However, due to the rarity of cases, the response of EGFR-TKIs in patients harboring uncommon compound EGFR mutations still needs to be determined. Here, we demonstrated the case of a 47-year-old smoker diagnosed with leptomeningeal metastasis from NSCLC and had EGFR20 R776S, C797S, and EGFR21 L858R compound mutations. He was treated with furmonertinib combined with intrathecal pemetrexed chemotherapy following progression on osimertinib, which led to clinical improvement and successfully prolonged his survival by 3 months. Regrettably, the patient eventually died from heart disease. This report provides the first reported evidence for the use of furmonertinib and intrathecal pemetrexed chemotherapy in NSCLC patients harboring EGFR R776S/C797S/L858R mutations who progressed on previous EGFR-TKIs.

The efficacy of slow-rate ventriculolumbar perfusion chemotherapy for leptomeningeal carcinomatosis: a phase II study.

PURPOSE: This study aimed to evaluate the symptomatic response and side effects of ventriculolumbar perfusion (VLP) methotrexate chemotherapy with a low perfusion rate in patients with leptomeningeal metastasis. METHODS: Patients in a single-arm, two-stage phase II trial based on Simon's minimax design received VLP with a reduced (15 cc/h) perfusion rate with the purpose of decreasing constitutional side effects such as nausea/vomiting, insomnia, and confusion. The primary outcome was control of increased intracranial pressure (ICP). The secondary outcome was an occurrence of side effects. The results were compared with those of a previous trial of VLP with a 20-cc/h perfusion rate. RESULTS: Total 90 patients were enrolled. Out of 65 patients with increased ICP, 32 achieved normalized ICP after VLP chemotherapy (bias-adjusted response rate = 51%). The incidence of moderate-to-severe nausea/vomiting was reduced to 46% from 64% in the previous study, and that of sleep disturbance was increased to 13% from 9%, but both failed to reach statistical significance. The incidence of moderate-to-severe confusion was significantly reduced to 12% from 23% in the previous study (p = 0.04). Median overall survival was better among patients with controlled ICP than among those who remained with increased ICP (193 days vs. 94 days, p = 0.013). CONCLUSION: Compared with a higher perfusion rate, the low perfusion rate failed to provide non-inferior ICP control or improved side effects, except for confusion. The relationship between VLP perfusion rate and ICP control needs to be evaluated in future trials adjusting for bias from uncompleted protocol due to poor general condition.

Efficacy and safety of intrathecal pemetrexed for TKI-failed leptomeningeal metastases from EGFR+ NSCLC: an expanded, single-arm, phase II clinical trial.

BACKGROUND: This study aimed to evaluate the efficacy and safety of intrathecal pemetrexed (IP) for treating patients with leptomeningeal metastases (LM) from non-small-cell lung cancer (NSCLC) who progressed from epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI) treatment in an expanded, prospective, single-arm, phase II clinical study (ChiCTR1800016615). PATIENTS AND METHODS: Patients with confirmed NSCLC-LM who progressed from TKI received IP (50 mg, day 1/day 5 for 1 week, then every 3 weeks for four cycles, and then once monthly) until disease progression or intolerance. Objectives were to assess overall survival (OS), response rate, and safety. Measurable lesions were assessed by investigator according to RECIST version 1.1. LM were assessed according to the Response Assessment in Neuro-Oncology (RANO) criteria. RESULTS: The study included 132 patients; 68% were female and median age was 52 years (31-74 years). The median OS was 12 months (95% confidence interval 10.4-13.6 months), RANO-assessed response rate was 80.3% (106/132), and the most common adverse event was myelosuppression (n = 42; 31.8%), which reversed after symptomatic treatment. The results of subgroup analysis showed that absence of brain parenchymal metastasis, good Eastern Cooperative Oncology Group score, good response to IP treatment, negative cytology after treatment, and patients without neck/back pain/difficult defecation had longer survival. Gender, age, previous intrathecal methotrexate/cytarabine, and whole-brain radiotherapy had no significant influence on OS. CONCLUSIONS: This study further showed that IP is an effective and safe treatment method for the EGFR-TKI-failed NSCLC-LM, and should be recommended for these patients in clinical practice and guidelines.

A Retrospective Real-World Study of Prognostic Factors Associated With EGFR Mutated Lung Cancer With Leptomeningeal Metastasis.

OBJECTIVE: To analyze the factors associated with EGFR-mutated lung cancer with leptomeningeal metastasis (LM) in the real world that affects the prognosis of patients. MATERIALS AND METHODS: The clinical data of 123 patients with advanced EGFR mutated lung cancer combined with LM treated at Henan Cancer Hospital and confirmed by histology between January 2016 and December 2020 were retrospectively collected, and all patients were followed up until September 2021. Analyze the median overall survival (mOS) time of patients with clinical characteristics and treatment factors to explore the factors influencing the prognosis of lung cancer patients with LM. RESULTS: A total of 123 patients with EGFR-mutated lung cancer and LM were included in this study. Overall, patients with exon 19 deletion (19del) in the classical mutation of the EGFR gene had a prolonged mOS compared to patients with exon 21 L858R mutation (21L858R) (30.1 months vs. 26.0 months); patients with primary LM (mOS 21.2 months) had a significantly shorter mOS than those with secondary LM (mOS 28.3 months); mOS was also significantly shorter in patients with combined brain metastases (mOS of 25.4 months) than in patients without combined brain metastases (mOS of 33.4 months); Patients treated with tyrosine kinase inhibitors (TKI) combined with antiangiogenic therapy (bevacizumab) experienced delayed onset of LM (mOS1: 19.4 months vs. 13.9 months), and prolonged survival after LM compared with those treated with EGFR-TKI alone (mOS2: 14.5 months vs. 10.0 months); There is no survival benefit to the patients treated with EGFR-TKI combined with chemotherapy compared to the patients treated with EGFR-TKI alone. CONCLUSION: Among NSCLC-LM patients with EGFR mutation, receiving EGFR-TKI combined with antiangiogenic therapy may result in a better survival benefit. The factors of primary LM, combined brain metastasis may be prognostic factors for poor OS.

Meningeal carcinomatosis with decreased visual acuity: a case report.

Meningeal carcinomatosis is a condition in which cancer cells diffusely metastasize to the cerebral pia mater in the cerebrospinal membrane or cerebrospinal cavity. It causes a wide array of symptoms according to the site of metastasis. The prognosis is poor, especially in metastasis from solid tumors. This study reports a case of meningeal carcinomatosis caused by advanced gastric cancer, manifested by headache and vision loss. The patient was a 69-year-old man who underwent head computed tomography (CT) and magnetic resonance imaging (MRI) for persistent headaches. No abnormal findings were found; however, his vision declined, convulsions occurred, and cerebrospinal fluid (CSF) cytology showed poorly differentiated adenocarcinoma. Therefore, meningeal carcinomatosis was diagnosed. The patient died after receiving FOLFOX therapy to relieve symptoms and prolong his life. An autopsy showed no invasion of the optic nerve or surrounding tissues. As the frequency of complications of meningeal carcinomatosis in solid cancers is rare, it is crucial to actively suspect and make an early diagnosis.

An overview of the therapeutic strategies for neoplastic meningitis due to breast cancer: when and why?

INTRODUCTION: Neoplastic meningitis (NM), also known as leptomeningeal carcinomatosis, is characterized by the infiltration of tumor cells into the meninges, and poses a significant therapeutic challenge owing to its aggressive nature and limited treatment options. Breast cancer is a common cause of NM among solid tumors, further highlighting the urgent need to explore effective therapeutic strategies. This review aims to provide insights into the evolving landscape of NM therapy in breast cancer by collating existing research, evaluating current treatments, and identifying potential emerging therapeutic options. AREAS COVERED: This review explores the clinical features, therapeutic strategies, recent advances, and challenges of managing NM in patients with breast cancer. Its management includes multimodal strategies, including systemic and intrathecal chemotherapy, radiation therapy, and supportive care. This review also emphasizes targeted drug options and optimal drug concentrations, and discusses emerging therapies. Additionally, it highlights the variability in treatment outcomes and the potential of combination regimens to effectively manage NM in breast cancer. EXPERT OPINION: Challenges in treating NM include debates over clinical trial end points and the management of adverse effects. Drug resistance and low response rates are significant hurdles, particularly inHER2-negative breast cancer. The development of more precise and cost-effective medications with improved selectivity is crucial. Additionally, global efforts are needed for infrastructure development and cancer control considering the diverse nature of the disease.

Pharmacotherapy for leptomeningeal disease in breast cancer.

Clinical data supporting the best therapeutic approach in leptomeningeal disease (LMD; also known as leptomeningeal metastases or leptomeningeal carcinomatosis) are lacking. Despite the development of new agents and increasing incidence of central nervous system metastases, patients with LMD are often excluded from clinical trials in breast cancer, with very few conducted specifically in LMD. Consequently, current evidence may not provide an accurate reflection of real-world clinical practice. This review aims to provide further insight into the treatment strategies for patients with breast cancer and LMD. We explore differences between clinical and real-world studies, considering inclusion criteria, levels of evidence for LMD diagnosis, and time between diagnosis of LMD and LMD-specific treatment initiation. Patient prognosis is poor; median overall survival is limited to several months, with approximately 10% of patients alive at 12 months. Efficacy results have been reported for various systemic and intrathecal agents in LMD to date. Systemic therapies under investigation for LMD in breast cancer include tucatinib, trastuzumab deruxtecan, and paclitaxel trevatide; trastuzumab is the main intrathecal agent currently under investigation. Recent trials investigating systemic or intrathecal therapies are typically small, single-arm studies, and most are restricted to patients with human epidermal growth factor receptor 2-positive breast cancer. Moreover, the variability among inclusion criteria and response assessment tools makes the interpretation of results difficult. Large retrospective cohorts with various inclusion criteria and treatment regimens provide some real-world data. However, there remains an urgent need for randomised clinical trials which include patients with LMD across all breast cancer subtypes.

Role of intrathecal chemotherapy in the management of meningeal carcinomatosis in patients with breast cancer.

OBJECTIVE: To evaluate whether intrathecal chemotherapy improves clinical outcomes in patients with meningeal carcinomatosis. METHODS: This retrospective cohort study included consecutive patients with breast cancer diagnosed with meningeal carcinomatosis. Clinical and treatment data were collected from the patients' medical charts. The primary outcome was overall survival, and the secondary outcomes were time to neurological deterioration and reporting of clinical benefit. Logistic regression and Cox proportional hazard models adjusted for potential confounders were used to evaluate the clinical response and overall survival, respectively. RESULTS: Overall, 109 female patients were included, 50 (45.9%) of whom received intrathecal chemotherapy with methotrexate and dexamethasone. The median treatment duration was 3 weeks (range, 1-13 weeks). Patients treated with intrathecal chemotherapy were more likely to report clinical benefit (74% versus 57.7%, adjusted odds ratio [OR] = 9.0, 95%CI=2.6-30.9, p<0.001). However, there was no difference in the time to neurologic deterioration (hazard ratio [HR] = 0.96, 95%CI= 0.57-1.59, p=0.86). Patients who received intrathecal chemotherapy did not show an increase in overall survival compared with that of patients who did not receive intrathecal chemotherapy (median overall survival = 1.8 months, 95%CI= 1.27-3.0 versus 2.5, 95%CI= 1.9-3.9, adjusted HR = 0.71, 95%CI= 0.41-1.22, p=0.21). There was a significant interaction between intrathecal chemotherapy and systemic treatment, and patients who received systemic therapy without intrathecal chemotherapy had better overall survival than that of the no-treatment group (adjusted HR = 0.38, 95%CI= 0.20-0.70, p=0.002). CONCLUSION: Intrathecal chemotherapy did not increase overall survival or time to neurological deterioration and should not preclude or postpone systemic treatments.

Effects of intrathecal pemetrexed on the survival of patients with leptomeningeal metastasis from lung adenocarcinoma: a propensity score matching analysis.

PURPOSE: To explore the impact of intrathecal pemetrexed (IP) on the survival of lung adenocarcinoma (LUAC) patients with leptomeningeal metastasis (LM). METHODS: We analyzed patients with LUAC and LM who received systemic therapy after LM diagnosis at the Fujian Cancer Hospital between July 2018 and March 2022. Patients who underwent IP were assigned to the IP group; those without IP treatment were designated as the non-IP group. Propensity score matching (PSM) was performed between the two groups. RESULTS: 165 patients were enrolled: 83 and 82 in the IP and non-IP groups, respectively. After 1:1 PSM, we included 114 patients in the matched cohort. Median overall survival (OS) was 13.2 months (95% CI 10.8-15.6 months) in the IP group versus 10.1 months (95% CI 5.3-14.9 months) in the non-IP group (P = 0.488). Only Eastern Cooperative Oncology Group Performance Status (ECOG PS) was confirmed as an independent predictor for OS in the matched cohort (hazard ratio (HR) 2.03; P = 0.023). Multivariate competing-risks analysis showed that IP significantly correlated with central nervous system-related death (HR 0.31; P = 0.046). When stratified by ECOG PS, IP improved survival in patients with poor ECOG PS (PS = 2) (14.3 months vs. 1.6 months; P = 0.003). CONCLUSIONS: Intrathecal pemetrexed did not enhance OS for the entire LUAC patient with LM compared to non-intrathecal chemotherapy. However, it exhibited the potential to reduce the risk of central nervous system-related mortality and improve survival in patients with poor ECOG PS.

Increasing discrepancy of MR imaging and CSF study in patients with leptomeningeal seeding from lung adenocarcinoma after targeted therapy using a tyrosine kinase inhibitor.

PURPOSE: To evaluate the correlation between contrast-enhanced (CE) MRI and cerebrospinal fluid (CSF) cytology for the evaluation of leptomeningeal metastasis (LM) on MRI after targeted therapy with tyrosine kinase inhibitors. METHODS: We retrospectively reviewed the data of nonsmall cell lung cancer patients registered with NCT03257124 from May 2017 to December 2018, with progressive disease despite targeted therapy. Twenty-nine patients whose MRI scans exhibited LM at the time of registration were enrolled. During the targeted therapy with osimertinib, MRI scans, and subsequent CSF examinations were performed in every 2 months. In total, 113 MRI scans and CSF cytology data after treatment were collected. For each CE MRI scan, LM positivity was evaluated on 3D T1-weighted image (T1WI) and 2D FLAIR. The correlation between MRI and CSF cytology results and the diagnostic performance of MRI with CSF cytology as a reference standard were evaluated. RESULTS: After treatment, MRI revealed positivity for LM in 81 and negativity in 32. CSF results were positive in 69 examinations and negative in 44. The diagnostic accuracy of CE 3D T1WI and 2D FLAIR was 0.52 and 0.46, respectively. After targeted therapy, discrepancy in the CSF and MRI results tended to increase over time. The proportions of concordant MRI and CSF cytology results after targeted therapy were 66%, 58%, 62%, and 47% at the first, second, third, and fourth follow-up, respectively. CONCLUSION: The discrepancy of MRI in evaluation of LM and CSF cytology increases over time after targeted therapy with osimertinib. LM positivity on MRI could be a surrogate imaging marker in the pre- and immediate posttargeted-treatment with Osimertinib but not after sessions of osimertinib.

HER2+ esophageal carcinoma leptomeningeal metastases treated with intrathecal trastuzumab regimen.

Materials & methods: We recently reported the largest trial of breast cancer patients with HER2 positive leptomeningeal metastases (LM) treated with trastuzumab. An additional treatment indication was explored as part of a single institution retrospective case series of HER2 positive esophageal adenocarcinoma LM (n = 2). Results: One patient received intrathecal trastuzumab (80 mg twice weekly) as part of their treatment regimen with durable long-term response and clearance of circulating tumor cells in the cerebral spinal fluid. The other patient demonstrated rapid progression and death as previously described in the literature. Conclusion: Intrathecal trastuzumab is a well-tolerated and reasonable therapeutic option worthy of further exploration for patients with HER2 positive esophageal carcinoma LM. An associative, but not a causal relationship, can be made regarding therapeutic intervention.

Cancer of the esophagus, the tube that connects the mouth to the stomach, tends to be aggressive. Very rarely, this cancer can spread to the lining that surrounds your brain, called the leptomeninges. Previous reports of patients who have experienced this specific spreading pattern of esophageal cancer to the leptomeninges are quite grim, with patients experiencing rapid decline and death within weeks to months. However, we write with two cases of esophageal cancer with this leptomeningeal spreading pattern, one of which involves a patient treated with a medication known as trastuzumab. As part of his long and complex course of treatment, this patient was given trastuzumab through a tube traveling directly to the area of the leptomeninges. This patient, now almost 2 years out from his initial diagnosis, has responded well to the treatment. As such, we believe that this specific treatment regimen as well as the ways in which our clinical team tracked this patient's response to medications are worth exploring further.

Efficacy of different platforms in detecting EGFR mutations using cerebrospinal fluid cell-free DNA from non-small-cell lung cancer patients with leptomeningeal metastases.

BACKGROUND: Cell-free tumor DNA (ctDNA) obtained through liquid biopsy is useful for the molecular analysis of advanced non-small-cell lung cancer (NSCLC). Few studies have directly compared analysis platforms in terms of their diagnostic performance in analyzing ctDNA obtained from the cerebrospinal fluid (CSF) of patients with leptomeningeal metastasis (LM). METHODS: We prospectively analyzed patients with epidermal growth factor receptor (EGFR)-mutant NSCLC who were subjected to CSF analysis for suspected LM. To detect EGFR mutations, CSF ctDNA was analyzed using the cobas EGFR Mutation Test and droplet digital polymerase chain reaction (ddPCR). CSF samples from osimertinib-refractory patients with LM were also subjected to next-generation sequencing (NGS). RESULTS: Significantly higher rates of valid results (95.1% vs. 78%, respectively, p = 0.04) and EGFR common mutation detection (94.3% vs. 77.1%, respectively, p = 0.047) were obtained through ddPCR than through the cobas EGFR Mutation Test. The sensitivities of ddPCR and cobas were 94.3% and 75.6%, respectively. The concordance rate for EGFR mutation detection through ddPCR and the cobas EGFR Mutation Test was 75.6% and that for EGFR mutation detection in CSF and plasma ctDNA was 28.1%. In osimertinib-resistant CSF samples, all original EGFR mutations were detected through NGS. MET amplification and CCDC6-RET fusion were demonstrated in one patient each (9.1%). CONCLUSIONS: The cobas EGFR Mutation Test, ddPCR, and NGS appear to be feasible methods for analyzing CSF ctDNA in patients with NSCLC and LM. In addition, NGS may provide comprehensive information regarding the mechanisms underlying osimertinib resistance.

Safety, Pharmacokinetic and Clinical Activity of Intrathecal Chemotherapy With Pemetrexed via the Ommaya Reservoir for Leptomeningeal Metastases From Lung Adenocarcinoma: A Prospective Phase I Study.

INTRODUCTION: Leptomeningeal metastasis (LM) is a highly fatal and debilitating complication of lung adenocarcinoma (LUAD) with limited therapeutic options. This study aimed to evaluate the efficacy and toxicities of intrathecal chemotherapy (IC) with pemetrexed via Ommaya reservoir in LUAD with refractory LM. METHODS: In this prospective, single-arm, phase I trial (ChiCTR2000028936), LUAD-LM patients who had progressed after at least two prior treatments were recruited. Pemetrexed from 30 mg to 50 mg was administered on Days 1 and 8 every 3 weeks via Ommaya reservoir. Serial samples of cerebrospinal fluid (CSF) and plasma were obtained for pharmacokinetic studies. The primary endpoint was progression-free survival (PFS), and the secondary endpoints included overall survival (OS), objective response rate (ORR), disease control rate (DCR), and therapeutic toxicities. RESULTS: Twenty-three patients were enrolled and analyzed, revealing an ORR of 43.5% (95% CI, 23.2%-63.8%) and DCR of 82.6% (95% CI, 61.2%-95.0%). The median PFS and OS were 6.3 and 9.5 months, respectively. Dose-limiting toxicity was only observed in 2 patients (2/23, 8.7%), and 30 mg pemetrexed was considered as the recommended dose for IC. Pharmacokinetic analysis showed that using Ommaya reservoirs, higher pemetrexed concentrations and prolonged half-lives were achieved in the CSF compared with lumbar puncture (LP). CONCLUSIONS: Intrathecal pemetrexed at a dose of 30 mg via Ommaya reservoirs on Days 1 and 8 every 21 days achieved promising disease control and satisfactory survival with moderate toxicities in resistant LUAD-LM, providing a feasible and effective option, especially for the patients who cannot tolerate LP.

Osimertinib Combined with Systemic Chemotherapy for EGFR Mutant, T790M-Negative, Non-Small Cell Lung Cancer Patients Who Develop Leptomeningeal Metastases with Extracranial Progression to Prior EGFR TKI.

Leptomeningeal metastasis (LM) is a rare but fatal clinical condition with a short survival time. The incidence of LM from epidermal growth factor receptor mutant (EGFRm) non-small cell lung cancer (NSCLC) has increased due to the limited efficacy of first- or second-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) in the central nervous system (CNS). Osimertinib is a third-generation, irreversible, CNS penetrant, oral EGFR TKI that demonstrates promising efficacy in CNS metastases regardless of T790M. Herein, we report four cases of T790M-negative EGFRm NSCLC patients treated with osimertinib combined with systemic chemotherapy, who progressed on prior EGFR TKI and developed LM with extracranial lesions. The combination treatment was well tolerated, and the mean overall survival from LM diagnosis was 14.7 months (95% confidence interval, 10.4 to 19.0). These results suggest that osimertinib combined with systemic chemotherapy would be a reasonable treatment option for T790M-negative EGFRm NSCLC patients who develop LM with extracranial progression to prior EGFR TKI. A further prospective study is warranted.

Prognosticators of osimertinib treatment outcomes in patients with EGFR-mutant non-small cell lung cancer and leptomeningeal metastasis.

PURPOSE: Leptomeningeal metastasis (LM) is a serious complication of non-small cell lung cancer (NSCLC), particularly in patients with EGFR mutations. In this study, we investigated the survival outcomes of patients with EGFR-mutant NSCLC who have developed LM and explored the factors associated with their survival. METHODS: From April 2018 to November 2021, patients with EGFR-mutant NSCLC who underwent cerebrospinal fluid (CSF) sampling under the clinical suspicion of LM were enrolled. The patients' clinicodemographic characteristics, treatment history including whole-brain radiation therapy (WBRT), overall survival (OS), and intracranial progression-free survival (icPFS) were measured. EGFR mutations in cell-free tumor DNA (ctDNA) of CSF, including T790M mutation, were analyzed. RESULTS: We enrolled 62 patients with NSCLC. The median time form diagnosis to LM was 23.1 months and 16 (25.8%) patients had history of prior third-generation EGFR-TKI use. EGFR mutation in CSF ctDNA was detected in 53 patients (85.5%); of them, 10 (16.1%) had T790M mutation. The patients' icPFS and OS after osimertinib were 6.43 and 9.37 months, respectively, and were comparable among patients with different sensitive EGFR mutations, indicating that EGFR mutation status did not affect osimertinib efficacy. Patients who received WBRT after LM had numerically higher icPFS and OS compared to those without. Multivariate analysis revealed that lack of prior exposure to third-generation EGFR-TKI was associated with better OS. CONCLUSIONS: Osimertinib is effective in patients with EGFR-mutant NSCLC who developed LM and prior third-generation EGFR-TKI use was associated with poor survival in these patients. The role of WBRT warrants further investigation.