Prospective validation of a new imaging scorecard to assess leptomeningeal metastasis: A joint EORTC BTG and RANO effort

Leptomeningeal metastases from solid tumors: A Society for Neuro-Oncology and American Society of Clinical Oncology consensus review on clinical management and future directions

Leptomeningeal metastases (LM) are increasingly becoming recognized as a treatable, yet generally incurable, complication of advanced cancer. As modern cancer therapeutics have prolonged the lives of patients with metastatic cancer, specifically in patients with parenchymal brain metastases, treatment options, and clinical research protocols for patients with LM from solid tumors have similarly evolved to improve survival within specific populations. Recent expansions in clinical investigation, early diagnosis, and drug development have given rise to new unanswered questions. These include leptomeningeal metastasis biology and preferred animal modeling, epidemiology in the modern cancer population, ensuring validation and accessibility of newer leptomeningeal metastasis diagnostics, best clinical practices with multimodality treatment options, clinical trial design and standardization of response assessments, and avenues worthy of further research. An international group of multi-disciplinary experts in the research and management of LM, supported by the Society for Neuro-Oncology and American Society of Clinical Oncology, were assembled to reach a consensus opinion on these pressing topics and provide a roadmap for future directions. Our hope is that these recommendations will accelerate collaboration and progress in the field of LM and serve as a platform for further discussion and patient advocacy.

Durable responses to trastuzumab deruxtecan in patients with leptomeningeal metastases from breast cancer with variable HER2 expression

PURPOSE

Emerging data suggest that trastuzumab deruxtecan (T-DXd) is an active treatment for brain metastases from HER2 + breast cancer. We aimed to characterize the activity of T-DXd in the treatment of leptomeningeal metastases (LM) from a range of HER2-altered cancers.

METHODS

We reviewed neuro-oncology clinic records between July 2020 and December 2023 to identify patients who received T-DXd to treat LM.

RESULTS

Of 18 patients identified, 6 had HER2 + breast cancer, 8 had HER2-low/negative breast cancer, 2 had HER2 + gastroesophageal cancer, and 2 had HER2-mutant non-small cell lung cancer (NSCLC). 10/18 (56%) patients had cytologically confirmed LM by CSF cytology or circulating tumor cell (CTC) capture. A partial response (PR) on MRI using the EORTC/RANO-LM Revised-Scorecard occurred in 4/6 (67%) patients with HER2 + breast LM, 2/8 (25%) patients with HER2-low/negative breast cancer, and 0/4 (0%) patients with HER2 + gastroesophageal cancer or HER2-mutant NSCLC. Median overall survival after initiating T-DXd was 5.8 months. Survival after initiating T-DXd was numerically longer for HER2 + breast cancer patients compared with HER2-low/negative breast and HER2-altered non-breast cancer patients (13.9 months vs. 5.2 months and 4.6 months, respectively). Landmark analysis showed that patients with radiologic LM response to T-DXd by 2.5 months had longer survival than non-responders (14.2 months vs. 2.6 months, HR 0.18, 95% CI 0.05-0.63, p < 0.05), and landmark analyses at 3.5 and 4.5 months after starting T-DXd showed a similar but nonsignificant trend.

CONCLUSION

T-DXd induces LM responses in a subset of patients, and such responses may be associated with prolongation of survival. Prospective trials are needed to clarify the role of T-DXd in treating LM and which patients are most likely to benefit.

A comprehensive review of current treatment modalities for leptomeningeal carcinomatosis in breast cancer

Leptomeningeal carcinomatosis (LC) is a metastatic complication of breast cancer that imparts a very poor prognosis and distressing neurologic symptoms in affected patients. While the incidence of LC has risen with improving survival rates for cancer patients, there remains no established treatment protocol for LC and clinical trial data comparing available therapies is limited. Here, a comprehensive literature search of the pubmed and Cochrane databases was performed. Current treatment modalities and their safety/ efficacy profiles are summarized for LC in breast cancer. Roles for emerging therapies in LC are discussed, including targeted agents, CAR-T, immune checkpoint inhibitors, CDK inhibitors and novel antibody conjugates. A treatment pathway for LC is also proposed to guide clinicians through management of this severe metastatic complication of breast cancer.

Towards consistency in pediatric brain tumor measurements: Challenges, solutions, and the role of artificial intelligence-based segmentation

MR imaging is central to the assessment of tumor burden and changes over time in neuro-oncology. Several response assessment guidelines have been set forth by the Response Assessment in Pediatric Neuro-Oncology (RAPNO) working groups in different tumor histologies; however, the visual delineation of tumor components using MRIs is not always straightforward, and complexities not currently addressed by these criteria can introduce inter- and intra-observer variability in manual assessments. Differentiation of non-enhancing tumors from peritumoral edema, mild enhancement from absence of enhancement, and various cystic components can be challenging; particularly given a lack of sufficient and uniform imaging protocols in clinical practice. Automated tumor segmentation with artificial intelligence (AI) may be able to provide more objective delineations, but rely on accurate and consistent training data created manually (ground truth). Herein, this paper reviews existing challenges and potential solutions to identifying and defining subregions of pediatric brain tumors (PBTs) that are not explicitly addressed by current guidelines. The goal is to assert the importance of defining and adopting criteria for addressing these challenges, as it will be critical to achieving standardized tumor measurements and reproducible response assessment in PBTs, ultimately leading to more precise outcome metrics and accurate comparisons among clinical studies.

"Symptomatic" melanoma brain metastases: A call for clear definitions and adoption of standardized tools

With improved systemic treatment and prolonged survival even with metastatic disease, diagnosing, treating, and monitoring brain metastases has become a central topic in the care of patients with melanoma. Patients with brain metastases from melanoma are typically excluded from pivotal clinical trials. When allowed, inclusion and exclusion criteria are rather selective and do not reflect the larger population of melanoma patients with brain metastases who frequently present with neurological symptoms and signs and require steroid medications. Moreover, the lack of consensus on reporting symptomatic brain involvement complicates the interpretation and implications of trial results for the overall population of patients with melanoma and brain metastasis. Here, we review the evidence regarding brain metastasis from melanoma and discuss the challenges of longitudinal neurological clinical assessments, including tools to capture cognition and quality of life. Finally, we propose the adoption of standardized tools to interpret neurological deficits in patients with melanoma and brain metastases and to assess the neurological status in the context of clinical trials.

Survival and treatment outcomes in patients with leptomeningeal disease from metastatic melanoma

Background

Melanoma leptomeningeal disease (LMD) has a poor prognosis. However, the management of patients with advanced melanoma has evolved with time, including those with LMD. We reviewed a large cohort of melanoma LMD patients to assess factors associated with survival.

Methods

Retrospective clinical data was collected on patients diagnosed with LMD at MD Anderson Cancer Center from 2015 to 2020. Overall survival (OS) was determined from LMD diagnosis to date of death or last follow-up. The Kaplan-Meier method and log-rank test were used to estimate OS and to assess univariate group differences, respectively. Multivariable associations of survival with variables of interest were determined using Cox proportional hazards regression models.

Results

A total of 172 patients were identified. The median age at LMD diagnosis was 53 (range 20-79) years, and all patients had radiographic evidence of LMD on magnetic resonance imaging of either brain or spine. In total 143 patients previously received systemic therapy (83%), with a median of 2 prior treatments (range 0-5). 81 patients (47%) had concurrent uncontrolled systemic disease and 80 patients (53%) had elevated serum LDH at the time of diagnosis. With a median follow-up of 4.0 months (range 0.1-65.3 months), median OS for all patients from LMD diagnosis was 4.9 months. Patients (n = 45) who received intrathecal therapy or systemic immunotherapy for LMD had a median OS of 8.0 months and 10.2 months, respectively. On multivariable analysis, decreased performance status, positive CSF cytology, elevated LDH, and whole brain radiation were associated with worse OS.

Conclusions

Despite many advances in therapeutic options, the outcomes of melanoma patients with LMD remains poor. However, a subset of patients appears to derive benefit from LMD-directed treatment.

Leptomeningeal Carcinomatosis in Early Gastric Cancer: A Case Report and Literature Review

Leptomeningeal carcinomatosis (LC) is a rare site of metastasis in solid tumors, and it is associated with poor prognosis due to disabling symptoms and a scarcity of treatment options. This condition is an uncommon entity in gastric cancer (GC). We present a case of primary LC manifestation in a patient with an incidental diagnosis of localized node-negative GC. We additionally perform a literature review and discuss the diagnostic and therapeutic challenges. In conclusion, LC from GC represents a rare condition with a dramatic prognosis. Its diagnosis might be very challenging. A multidisciplinary approach appears to be the best strategy for the management of LC from GC.

Prognostic impact of clinical and radiological factors on leptomeningeal metastasis from solid cancers

PURPOSE

The number of leptomeningeal metastasis (LM) patients has increased in recent years, as the cancer survival rates increased. An optimal prediction of prognosis is essential for selecting an appropriate treatment. The European Association of Neuro-Oncology-European Society for Medical Oncology (EANO-ESMO) guidelines for LM proposed a classification based on the cerebrospinal fluid cytological findings and contrast-enhanced magnetic resonance imaging (MRI) pattern. However, few studies have validated the utility of this classification. This study aimed to investigate the prognostic factors of LM, including the radiological and cytological types.

METHODS

We retrospectively analyzed the data of 240 adult patients with suspected LM who had undergone lumbar puncture between April 2014 and September 2021.

RESULTS

The most common primary cancer types were non-small-cell lung cancer (NSCLC) (143 (60%)) and breast cancer (27 (11%)). Positive cytology results and the presence of leptomeningeal lesions on contrast-enhanced MRI correlated with decreased survival in all patients. Nodular lesions detected on contrast-enhanced magnetic resonance were a poor prognostic factor in cytology-negative patients, while contrast-enhanced patterns had no prognostic significance in cytology-positive patients. Systemic therapy using cytotoxic agents and molecular-targeted therapy after LM diagnosis correlated with prolonged survival, regardless of the cytology results. Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor treatment and systemic chemotherapy after LM improved the survival of EGFR-mutated and wild-type NSCLC patients with positive cytology results.

CONCLUSIONS

This study validated the efficacy of prognostication according to the EANO-ESMO guidelines for LM. Systemic therapy after LM diagnosis improves the survival of NSCLC patients.

Prognostic Role of Ventricular Size and Its Dynamics in Patients With Leptomeningeal Metastasis From Solid Tumors

BACKGROUND AND OBJECTIVES

Hydrocephalus is a common radiologic sign in patients with leptomeningeal metastasis (LM) from solid tumors which can be assessed using the Evans index (EI). Here, we explored the prognostic value of ventricular size in LM.

METHODS

We identified patients with LM from solid tumors by chart review at 3 academic hospitals to explore the prognostic associations of the EI at diagnosis, first follow-up, and progression.

RESULTS

We included 113 patients. The median age was 58.3 years (interquartile range [IQR] 46.1-65.8), 41 patients (36%) were male, and 72 patients (64%) were female. The most frequent cancers were lung cancer (n = 39), breast cancer (n = 36), and melanoma (n = 23). The median EI at baseline was 0.28 (IQR 0.26-0.31); the EI value was 0.27 or more in 67 patients (59%) and 0.30 or more in 37 patients (33%). Among patients with MRI follow-up, the EI increased by 0.01 or more in 16 of 31 patients (52%), including 8 of 30 patients (30%) without and 10 of 17 patients (59%) with LM progression at first follow-up. At LM progression, an increase of EI of 0.01 or more was noted in 18 of 34 patients (53%). The median survival was 2.9 months (IQR 1-7.2). Patients with a baseline EI below 0.27 had a longer survival than those with an EI of 0.27 or more (5.3 months, IQR 2.4-10.8, vs 1.3 months, IQR 0.6-4.1) (HR 1.70, 95% CI 1.135-2.534, p = 0.0099). The median survival was 3.7 months (IQR 1.4-8.3) with an EI below 0.30 vs 1.8 months (IQR 0.8-4.1) with an EI of 0.30 or more (HR 1.40, 95% CI 0.935-1.243, p = 0.1113). Among patients with follow-up scans available, the overall survival was 9.4 months (IQR 5.6-21.0) for patients with stable or decreased EI at first follow-up as opposed to 5.6 months (IQR 2.5-10.5) for those with an increase in the EI (HR 1.08, 95% CI 0.937-1.243; p = 0.300).

DISCUSSION

The EI at baseline is prognostic in LM. An increase of EI during follow-up may be associated with inferior LM progression-free survival. Independent validation cohorts with larger sample size and evaluation of confounding factors will help to better define the clinical utility of EI assessments in LM.

The early recognition and diagnosis of neoplastic meningitis

INTRODUCTION

The diagnosis and monitoring of leptomeningeal metastases (LM) from solid tumors are challenging, and the combination of neurological symptoms, MRI findings, and cerebrospinal fluid (CSF) cytology does not always allow to achieve a definitive diagnosis.

AREAS COVERED

This review summarizes the studies that have investigated CSF liquid biopsy to improve the initial diagnosis of LM in case the CSF cytology is negative or only suspicious for tumor cells, and monitoring of tumor response following targeted therapies or immunotherapy. In this regard, the early detection of LM recurrence and the development of resistant mutations are critical issues. Moreover, the early identification of subgroups of patients with a higher risk of LM progression, as well as the correlation of LM burden with survival, are discussed.

EXPERT OPINION

There is an urgent need of prospective studies to monitor longitudinally LM using CSF liquid biopsy and investigate the role of CTC, ctDNA or novel assays. The optimal setting for the longitudinal CSF and blood collection can be clinical trials focused on the molecular diagnosis of LM as well as the response and monitoring following targeted agents.

Therapeutic strategies for HER2-positive breast cancer with central nervous system involvement: a literature review and future perspectives

Background and Objective

Brain metastases (BMs) are present in approximately 55% of patients with HER2-positive breast cancer (HER2+ BC). The introduction of anti-HER2 agents has radically changed the prognosis of these patients by prolonging overall survival.

Methods

In this review, we describe the biology of central nervous system (CNS) spreading in patients with HER2+ BC. We also provide a literature review of current treatment strategies of brain metastatic BC, focusing on HER2+ disease, and future perspectives.

Key Content and Findings

Treatment of symptomatic BMs includes traditionally neurosurgery and/or radiotherapy, depending on the number of metastases, performance status and systemic disease control. Local treatments, such as surgical excision of BM and stereotactic radiosurgery (SRS), when feasible, are preferred over whole-brain radiotherapy, because of related cognitive impairment. These treatments can lead to a local control of the disease, however, systemic relapses can affect the prognosis of these patients. Recently, new anti-HER2 agents have demonstrated to be effective on BMs, thereby leading to improved survival outcomes with an acceptable quality of life. Despite the clinical benefit of these approaches, BMs still represent a cause of death and effective therapeutic strategies are needed.

Conclusions

Different targeted agents have demonstrated significant efficacy with tolerable safety profiles in HER2+ BC patients with BM, and have already been approved for clinical use in this setting. A better understanding of the molecular mechanisms underlying the onset of BMs could suggest novel targeted approaches in order to prevent CNS localization or delay progression to CNS in HER-2 metastatic patients.

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.

Treatment with trastuzumab deruxtecan in patients with HER2-positive breast cancer and brain metastases and/or leptomeningeal disease (ROSET-BM)

Therapeutic options for breast cancer patients with brain metastases (BM)/leptomeningeal carcinomatosis (LMC) are limited. Here, we report on the effectiveness and safety of trastuzumab deruxtecan (T-DXd) in human epidermal growth factor receptor 2-positive breast cancer patients with BM. Data were analyzed for 104 patients administered T-DXd. Overall response rate (ORR), progression-free survival (PFS), overall survival (OS), intracranial (IC)-ORR, and IC-PFS were evaluated. ORR by investigator assessment was 55.7% (total population). Median PFS was 16.1 months; 12-month OS rate was 74.9% (total population). Median time-to-treatment failure was 9.7 months. In 51 patients with BM imaging, IC-ORR and median IC-PFS by independent central review were 62.7% and 16.1 months, respectively. In 19 LMC patients, 12-month PFS and OS rates were 60.7% and 87.1%, respectively. T-DXd showed effectiveness regarding IC-ORR, IC-PFS, PFS, and OS in breast cancer patients with BM/active BM, and sustained systemic and central nervous system disease control in LMC patients.Trial Registration: UMIN000044995.

The role of clinical imaging in oncology drug development: progress and new challenges

In 2008, the role of clinical imaging in oncology drug development was reviewed. The review outlined where imaging was being applied and considered the diverse demands across the phases of drug development. A limited set of imaging techniques was being used, largely based on structural measures of disease evaluated using established response criteria such as response evaluation criteria in solid tumours. Beyond structure, functional tissue imaging such as dynamic contrast-enhanced MRI and metabolic measures using [18F]flourodeoxyglucose positron emission tomography were being increasingly incorporated. Specific challenges related to the implementation of imaging were outlined including standardisation of scanning across study centres and consistency of analysis and reporting. More than a decade on the needs of modern drug development are reviewed, how imaging has evolved to support new drug development demands, the potential to translate state-of-the-art methods into routine tools and what is needed to enable the effective use of this broadening clinical trial toolset. In this review, we challenge the clinical and scientific imaging community to help refine existing clinical trial methods and innovate to deliver the next generation of techniques. Strong industry-academic partnerships and pre-competitive opportunities to co-ordinate efforts will ensure imaging technologies maintain a crucial role delivering innovative medicines to treat cancer.

Leptomeningeal metastasis from solid tumours: EANO-ESMO Clinical Practice Guideline for diagnosis, treatment and follow-up

•This Clinical Practice Guideline provides recommendations for managing leptomeningeal metastases from solid tumours. •The guideline covers clinical, imaging and cytological diagnosis, staging and risk assessment, treatment and follow-up. •A treatment and management algorithm is provided. •The author panel encompasses a multidisciplinary group of experts from different institutions and countries in Europe. •Recommendations are based on available scientific data and the authors’ collective expert opinion.

A phase II study of concurrent involved-field radiotherapy and intrathecal chemotherapy for leptomeningeal metastasis from solid tumors

BACKGROUND

The role of involved-field radiation therapy (IFRT) and intrathecal chemotherapy (IC) in leptomeningeal metastasis (LM) from solid tumors was gradually underestimated in the era of targeted therapy. This study was aimed to investigate the safety and effectiveness of concurrent IFRT and intrathecal methotrexate (MTX)/cytarabine (Ara-C) for LM, particularly for those who developed LM while receiving targeted therapy.

MATERIALS AND METHODS

Enrolled patients were given induction IC first and then concurrent treatment, which consisted of IFRT (40 Gy total; 2 Gy/f) and IC (MTX 15 mg or Ara-C 50 mg, once per week). Primary endpoint was clinical response rate (RR). Secondary endpoints were safety and overall survival (OS).

RESULTS

Fifty-three patients received induction intrathecal MTX (n = 27) or Ara-C (n = 26). Forty-two patients completed concurrent therapy. Total RR was 34% (18/53). The improvement rate of neurological symptoms and KPS scores were 72% (38/53) and 66% (35/53) respectively. Adverse events (AEs) rate was 28% (15/53). Eight patients (15%, 8/53) showed grade 3-4 AEs, including myelosuppression (n = 4) and radiculitis (n = 5). Median OS was 6.5 months (95% CI, 5.3-7.7 months). Median survival for 18 patients who had clinical response was 7.9 months (95% CI, 4.4-11.4 months), and 0.8 months (95% CI, 0.08-1.5 months) for 6 patients who had LM progression. The median survival in 22 patients who received prior targeted therapy was 6.3 months (95% CI, 4.5-8.1 months).

CONCLUSION

Concurrent IFRT and intrathecal MTX or Ara-C was proved to be a feasible treatment option with an acceptable safety profile for LM from a common tumor entity.

Diagnostic and Therapeutic Updates in Leptomeningeal Disease

PURPOSE OF REVIEW

Leptomeningeal disease (LMD) is a devastating complication of advanced metastatic cancer associated with a poor prognosis and limited treatment options. This study reviews the current understanding of the clinical presentation, pathogenesis, diagnosis, and treatment of LMD. We highlight opportunities for advances in this disease.

RECENT FINDINGS

In recent years, the use of soluble CSF biomarkers has expanded, suggesting improved sensitivity over traditional cytology, identification of targetable mutations, and potential utility for monitoring disease burden. Recent studies of targeted small molecules and intrathecal based therapies have demonstrated an increase in overall and progression-free survival. In addition, there are several ongoing trials evaluating immunotherapy in LMD. Though overall prognosis of LMD remains poor, studies suggest a potential role for soluble CSF biomarkers in diagnosis and management and demonstrate promising findings in patient outcomes with targeted therapies for specific solid tumors. Despite these advances, there continues to be a gap of knowledge in this disease, emphasizing the importance of inclusion of LMD patients in clinical trials.

Comparison of clinical outcomes of osimertinib and first-generation EGFR-tyrosine kinase inhibitors (TKIs) in TKI-untreated EGFR-mutated non-small-cell lung cancer with leptomeningeal metastases

BACKGROUND

Leptomeningeal metastases (LM) are devastating complications of epidermal growth factor receptor (EGFR)-mutated non-small-cell lung cancer (NSCLC). Although osimertinib, a third-generation EGFR-tyrosine kinase inhibitor (TKI), has better penetration into the central nervous system than first-generation EGFR-TKIs, data on the distinct activity of EGFR-TKIs in untreated advanced EGFR-mutated NSCLC with LM are lacking.

PATIENTS AND METHODS

We retrospectively reviewed patients treated with EGFR-TKIs for TKI-untreated common EGFR-mutated NSCLC with LM between July 2002 and July 2021 at the National Cancer Center Hospital. The patients were divided into two groups: patients treated with osimertinib (Osi group) and those treated with gefitinib or erlotinib [first-generation (1G)-TKI group].

RESULTS

Of the 967 patients, 71 were eligible, including 29 in the Osi group and 42 in the 1G-TKI group. The median progression-free survival (PFS) and overall survival (OS) in the Osi group were better than those in the 1G-TKI group (PFS: 16.9 months versus 8.6 months, P = 0.007, and OS: 26.6 months versus 20.0 months, P = 0.158). The LM-overall response rate (ORR) and LM-PFS were significantly better in the Osi group than in the 1G-TKI group (LM-ORR: 62.5% versus 25.7%, P = 0.007; LM-PFS: 23.4 months versus 12.1 months, P = 0.021). In the subgroup analysis of EGFR mutation status, LM-PFS for patients with exon 19 deletion was significantly longer in the Osi group than in the 1G-TKI group (32.7 months versus 13.4 months, P = 0.013), whereas those with L858R mutation in exon 21 did not differ between the two groups. In the multivariate analysis, osimertinib and exon 19 deletion were significant factors for better LM-PFS and OS.

CONCLUSION

Osimertinib can be more effective for untreated common EGFR-mutated NSCLC patients with LM, especially those with exon 19 deletion, compared to first-generation TKIs.

Intrathecal trastuzumab versus alternate routes of delivery for HER2-targeted therapies in patients with HER2+ breast cancer leptomeningeal metastases

BACKGROUND

Patients with HER2+ breast cancer (BC) frequently develop leptomeningeal metastases (LM). While HER2-targeted therapies have demonstrated efficacy in the neoadjuvant, adjuvant, and metastatic settings, including for parenchymal brain metastases, their efficacy for patients with LM has not been studied in a randomized controlled trial. However, several single-armed prospective studies, case series and case reports have studied oral, intravenous, or intrathecally administered HER2-targeted therapy regimens for patients with HER2+ BC LM.

METHODS

We conducted a systematic review and meta-analysis of individual patient data to evaluate the efficacy of HER2-targeted therapies in HER2+ BC LM in accordance with PRISMA guidelines. Targeted therapies evaluated were trastuzumab (intrathecal or intravenous), pertuzumab, lapatinib, neratinib, tucatinib, trastuzumab-emtansine and trastuzumab-deruxtecan. The primary endpoint was overall survival (OS), with CNS-specific progression-free survival (PFS) as a secondary endpoint.

RESULTS

7780 abstracts were screened, identifying 45 publications with 208 patients, corresponding to 275 lines of HER2-targeted therapy for BC LM which met inclusion criteria. In univariable and multivariable analyses, we observed no significant difference in OS and CNS-specific PFS between intrathecal trastuzumab compared to oral or intravenous administration of HER2-targeted therapy. Anti-HER2 monoclonal antibody-based regimens did not demonstrate superiority over HER2 tyrosine kinase inhibitors. In a cohort of 15 patients, treatment with trastuzumab-deruxtecan was associated with prolonged OS compared to other HER2-targeted therapies and compared to trastuzumab-emtansine.

CONCLUSIONS

The results of this meta-analysis, comprising the limited data available, suggest that intrathecal administration of HER2-targeted therapy for patients with HER2+ BC LM confers no additional benefit over oral and/or IV treatment regimens. Although the number of patients receiving trastuzumab deruxtecan in this cohort is small, this novel agent offers promise for this patient population and requires further investigation in prospective studies.

Radiological response of leptomeningeal metastases according to revised RANO criteria is associated with overall survival in breast cancer patients

Assessment of treatment response in patients (pts) with leptomeningeal metastases (LM) represents a significant challenge and standardized criteria are needed. In 2017, the RANO LM Working Group proposed a standardized scorecard to evaluate MRI findings (further simplified in 2019). Here, we aim to validate the prognostic impact of response to treatment assessed using this tool in a multicentric cohort of breast cancer (BC) pts. Pts with BC-related LM diagnosed at two institutions between 2005 and 2018 were identified. Baseline and follow-up MRI scans were centrally reviewed and response assessment was evaluated using 2019 revised RANO LM criteria. A total of 142 pts with BC-related LM and available baseline brain MRI imaging were identified; 60 of them had at least one follow-up MRI. In this subgroup, median overall survival (OS) was 15.2 months (95%CI 9.5-21.0). At first re-evaluation, radiological response by RANO criteria was: complete response (CR) in 2 pts (3%), partial response (PR) in 12 (20%), stable disease (SD) in 33 (55%) and progression of disease (PD) in 13 (22%). Median OS was 31.1 months (HR 0.10, 95%CI 0.01-0.78) in pts with CR, 16.1 months (HR 0.41, 95%CI 0.17-0.97) in pts with PR, 17.9 months (HR 0.45, 95%CI 0.22-0.91) in pts with SD and 9.5 months in pts with PD (P = .029). A second blinded evaluation showed a moderate interobserver agreement (K = 0.562). Radiological response according to 2019 RANO criteria is significantly associated with OS in pts with BC-related LM, thus supporting the use of this evaluation tool both in trials and clinical practice.

Assessment of Phase 3 Randomized Clinical Trials Including Patients With Leptomeningeal Disease: A Systematic Review

This systematic review examines the proportion of patients with leptomeningeal disease included in phase 3 randomized clinical trials for patients with metastatic breast cancer, lung cancer, and melanoma.

Durable responses in patients with HER2+ breast cancer and leptomeningeal metastases treated with trastuzumab deruxtecan

Leptomeningeal metastases (LM) are a devastating complication of HER2 + metastatic breast cancer (MBC), with no effective treatments. In a case series of 8 patients with heavily pretreated HER2 + MBC and progressing LM, all 8 patients (100%) derived clinical benefit from Trastuzumab deruxtecan (TDXd), and 4 patients (50%) had an objective partial response based on formal neuroradiology MRI reads using the EORTC/RANO-LM Revised-Scorecard. T-DXd warrants further study in LM in HER2 + MBC and solid tumors where T-DXd may be active.

Radiotherapy for Leptomeningeal Carcinomatosis in Breast Cancer Patients: A Narrative Review

Simple Summary

Leptomeningeal carcinomatosis (LC) is a rare event in breast cancer (BC) patients that carries an abysmal prognosis. Little progress has been made in this field in the last few decades. Despite innovations in radiotherapy (RT), there is no univocal evidence of its impact on survival. Due to the rarity of the diagnosis, only a few prospective trials have evaluated the role of RT for LC in BC. Nonetheless, most BC patients with LC currently receive RT, depending on local protocols and individual convictions. This review presents the current knowledge on the indications and feasibility of RT for LC in BC, focusing on new technologies and perspectives.

Abstract

Leptomeningeal carcinomatosis (LC), defined as the infiltration of the leptomeninges by cancer cells, is a rare oncological event with the most common etiology being breast cancer (BC), lung cancer, and melanoma. Despite innovations in radiotherapy (RT), firm evidence of its impact on survival is lacking, and concerns are related to its possible neurotoxicity. Owing to a paucity of data, the optimal treatment strategy for LC remains unknown. This review discusses current approaches, indications, and contraindications for various forms of RT for LC in BC. A separate section is dedicated to new RT techniques, such as proton therapy. We also summarize ongoing clinical trials evaluating the role of RT in patients with LC.

Clinical implications of the 2021 edition of the WHO classification of central nervous system tumours

A new edition of the WHO classification of tumours of the CNS was published in 2021. Although the previous edition of this classification was published just 5 years earlier, in 2016, rapid advances in our understanding of the molecular underpinnings of CNS tumours, including the diversity of clinically relevant molecular types and subtypes, necessitated a new classification system. Compared with the 2016 scheme, the new classification incorporates even more molecular alterations into the diagnosis of many tumours and reorganizes gliomas into adult-type diffuse gliomas, paediatric-type diffuse low-grade and high-grade gliomas, circumscribed astrocytic gliomas, and ependymal tumours. A number of new entities are incorporated into the 2021 classification, especially tumours that preferentially or exclusively arise in the paediatric population. Such a substantial revision of the WHO scheme will have major implications for the diagnosis and treatment of patients with CNS tumours. In this Perspective, we summarize the main changes in the classification of diffuse and circumscribed gliomas, ependymomas, embryonal tumours and meningiomas, and discuss how each change will influence post-surgical treatment, clinical trial enrolment and cooperative studies. Although the 2021 WHO classification of CNS tumours is a major conceptual advance, its implementation on a routine clinical basis presents some challenges that will require innovative solutions.