Hormone receptors status: a strong determinant of the kinetics of brain metastases occurrence compared with HER2 status in breast cancer

Metastatic site patterns by intrinsic subtype and HER2DX in early HER2-positive breast cancer

BACKGROUND

Even with contemporary treatment strategies, more than 10% of HER2-positive early stage breast cancer patients may experience distant metastasis as first event during follow-up. Tools for predicting unique patterns of metastatic spread are needed to plan personalized surveillance. We evaluated how molecular heterogeneity affects the pattern of distant relapse in HER2-positive breast cancer.

METHODS

A total of 677 HER2-positive stage I-III breast cancer patients from ShortHER trial, Cher-LOB trial, and 2 institutional cohorts were included. PAM50 molecular subtypes and research-based HER2DX scores were evaluated. The cumulative incidence of distant relapse as the first event (any site and site specific) was evaluated using competing risk analysis. Median follow-up was 8.4 years. Tests of statistical significance are 2-sided.

RESULTS

Stage III and high HER2DX risk score identified patients at the highest risk of distant relapse as first event (10-year incidence 24.5% and 19.7%, respectively). Intrinsic molecular subtypes were associated with specific patterns of metastatic spread: compared with other subtypes, HER2-enriched tumors were more prone to develop brain metastases (10-year incidence 3.8% vs 0.6%, P = .005), basal-like tumors were associated with an increased risk of lung metastases (10-year incidence 11.1% vs 2.6%, P = .001), and luminal tumors developed more frequently bone-only metastases (10-year incidence 5.1% vs 2.0%, P = .042). When added to stage or HER2DX risk score in competing risk regression models, intrinsic subtype maintained an independent association with site-specific metastases.

CONCLUSIONS

The integration of intrinsic molecular subtypes with stage or HER2DX risk score predicts site-specific metastatic risk in HER2-positive breast cancer, with potential implications for personalized surveillance and clinical trials aimed at preventing site-specific recurrence.

Multidisciplinary management of HER2-positive breast cancer with brain metastases: An evidence-based pragmatic approach moving from pathophysiology to clinical data

INTRODUCTION

About 30-50 % of stage IV HER2+ breast cancers (BC) will present brain metastases (BMs). Their management is based on both local treatment and systemic therapy. Despite therapeutic advances, BMs still impact on survival and quality of life and the development of more effective systemic therapies represents an unmet clinical need.

MATERIALS AND METHODS

A thorough analysis of the published literature including ongoing clinical trials has been performed, investigating concepts spanning from the pathophysiology of tumor microenvironment to clinical considerations with the aim to summarize the current and future locoregional and systemic strategies.

RESULTS

Different trials have investigated monotherapies and combination treatments, highlighting how the blood-brain barrier (BBB) represents a major problem hindering diffusion and consequently efficacy of such options. Trastuzumab has long been the mainstay of systemic therapy and over the last two decades other HER2-targeted agents including lapatinib, pertuzumab, and trastuzumab emtansine, as well as more recently neratinib, tucatinib, and trastuzumab deruxtecan, have been introduced in clinical practice after showing promising results in randomized controlled trials.

CONCLUSIONS

We ultimately propose an evidence-based treatment algorithm for clinicians treating HER2 + BCs patients with BMs.

Prognostic impact of extracranial disease control in HER2+ breast cancer-related brain metastases

BACKGROUND

Brain metastases (BM) are common among HER2+ breast cancer (BC) and prognostic stratification is crucial for optimal management. BC-GPA score and subsequent refinements (modified-GPA, updated-GPA) recapitulate prognostic factors. Since none of these indexes includes extracranial disease control, we evaluated its prognostic value in HER2+ BCBM.

METHODS

Patients diagnosed with HER2+ BCBM at Istituto Oncologico Veneto-Padova (2002-2021) and Montpellier Cancer Institute (2001-2015) were included as exploratory and validation cohorts, respectively. Extracranial disease control at BM diagnosis (no disease/stable disease/response vs. progressive disease) was evaluated.

RESULTS

In the exploratory cohort of 113 patients (median OS 12.2 months), extracranial control (n = 65, 57.5%) was significantly associated with better OS at univariate (median OS 17.7 vs. 8.7 months, p = 0.005) and multivariate analysis after adjustment for BC-GPA (HR 0.61, 95% CI 0.39-0.94), modified-GPA (HR 0.64, 95% CI 0.42-0.98) and updated-GPA (HR 0.63, 95% CI 0.41-0.98). The prognostic impact of extracranial disease control (n = 66, 56.4%) was then confirmed in the validation cohort (n = 117) at univariate (median OS 20.2 vs. 9.1 months, p < 0.001) and multivariate analysis adjusting for BC-GPA (HR 0.41, 95% CI 0.27-0.61), modified-GPA (HR 0.44, 95% CI 0.29-0.67) and updated-GPA (HR 0.42, 95% CI 0.28-0.63).

CONCLUSIONS

Extracranial disease control provides independent prognostic information in HER2+ BCBM beyond commonly used prognostic scores.

Interactive exploration of a global clinical network from a large breast cancer cohort

Despite unprecedented amount of information now available in medical records, health data remain underexploited due to their heterogeneity and complexity. Simple charts and hypothesis-driven statistics can no longer apprehend the content of information-rich clinical data. There is, therefore, a clear need for powerful interactive visualization tools enabling medical practitioners to perceive the patterns and insights gained by state-of-the-art machine learning algorithms. Here, we report an interactive graphical interface for use as the front end of a machine learning causal inference server (MIIC), to facilitate the visualization and comprehension by clinicians of relationships between clinically relevant variables. The widespread use of such tools, facilitating the interactive exploration of datasets, is crucial both for data visualization and for the generation of research hypotheses. We demonstrate the utility of the MIIC interactive interface, by exploring the clinical network of a large cohort of breast cancer patients treated with neoadjuvant chemotherapy (NAC). This example highlights, in particular, the direct and indirect links between post-NAC clinical responses and patient survival. The MIIC interactive graphical interface has the potential to help clinicians identify actionable nodes and edges in clinical networks, thereby ultimately improving the patient care pathway.

Molecular Subtypes, Metastatic Pattern and Patient Age in Breast Cancer: An Analysis of Italian Network of Cancer Registries (AIRTUM) Data

Breast cancer stage at diagnosis, patient age and molecular tumor subtype influence disease progression. The aim of this study was to analyze the relationships between these factors and survival in breast cancer patients among the Italian population using data from the AIRTUM national database. We enrolled women with primary breast cancer from 17 population-based cancer registries. Patients were subdivided into older (>69 years), middle (50–69 years) and younger age groups (<50 years) and their primary tumors categorized into four molecular subtypes based on hormone receptor (HR) and human epidermal growth factor receptor 2 (HER2) status. There were 8831 patients diagnosed between 2010 and 2012 included. The most represented age group was 50–69 years (41.7%). In 5735 cases the molecular subtype was identified: HER2–/HR+ was the most frequent (66.2%) and HER2+/HR− the least (6.2%). Of the 390 women with metastases at diagnosis, 38% had simultaneous involvement of multiple sites, independent of age and molecular profile. In women with a single metastatic site, bone (20% of cases), liver (11%), lung (7%) and brain (3%) were the most frequent. In the studied age groups with different receptor expression profiles, the tumor metastasized to target organs with differing frequencies, affecting survival. Five-year survival was lowest in women with triple-negative (HER2−/HR–) tumors and women with brain metastases at diagnosis.

Cerebral hemorrhage due to amyloid angiopathy that was difficult to differentiate from breast cancer metastasis: a case report

Background

Breast cancer patients are known to develop brain metastasis at a relatively high frequency. However, imaging findings of brain metastases vary, and it is sometimes very difficult to distinguish these from other tumorous lesions and non-neoplastic lesions, such as cerebral hemorrhage. Meanwhile, there are various causes of cerebral hemorrhage; a major one is cerebral amyloid angiopathy (CAA). With the advancement of imaging technology, CAA-related cerebral hemorrhage can be more precisely diagnosed with magnetic resonance imaging (MRI), but definitive diagnosis of CAA can only be made based on pathological assessment. Herein, we report a case of consciousness disorder appearing during adjuvant therapy for breast cancer. We initially considered that the patient’s cerebral hemorrhage was due to a metastatic tumor, but based on excisional biopsy, she was diagnosed with CAA.

Case presentation

A 73-year-old Japanese woman underwent curative surgery for left breast cancer. Her disease was hormone receptor-positive and human epidermal growth factor receptor 2 (HER2)-positive invasive ductal carcinoma (pStage IIB). While receiving adjuvant treatment, she developed disorientation, and emergent imaging revealed multiple cerebral hemorrhages. There was no apparent enhancement in the cerebral parenchyma on MRI, and differential diagnosis included hemorrhage due to a metastatic tumor, intravascular large B-cell lymphoma, CAA and thrombotic intracranial bleeding. After hospitalization, the bleeding lesion enlarged, resulting in cerebral hernia, and she needed emergency drainage surgery. The tissue surrounding the hemorrhage was pathologically assessed, and she was diagnosed with CAA. Although we initially suspected the lesion to be a metastatic tumor from breast cancer, there were no tumorous cells.

Conclusion

Atypical MRI findings made diagnosis difficult in this case, but it should be considered for differential diagnosis when multiple cerebral hemorrhages in elderly patients are observed, especially in cases with symptoms such as transient multifocal neurological deficits and dementia.

Factors affecting time to brain metastases for stage 2 and 3 breast cancer patients: A large single-institutional analysis with potential screening implications

Background

Breast cancer is the second most common cancer associated with brain metastases. The purpose of this study was to identify factors that impact the time to brain metastases in breast cancer patients at a single institution.

Methods

Single institution retrospective study that captured all consecutive stage 2 and stage 3 breast cancer patients from 2003 to 2010. Patient characteristics analyzed included age, hormone status, HER2 receptor status, grade, stage, and time from breast cancer diagnosis to brain metastasis.

Results

A total of 1218 patients were eligible for the final analysis. 849 (69.7%) patients were ER+/HER2−, 90 (7.4%) were HER2+, and 279 (22.9%) were triple-negative (TN). Overall, 74 patients (6.1%) developed brain metastases over a median follow up time of 92 months. Median times to brain metastases for HER2+, TN, and ER+/HER2− patients were 20, 26, and 57 months, respectively. Multivariate analysis demonstrated that TN disease (HR = 2.043, P = .015), grade (HR = 1.667, P = .024) and stage (HR = 3.851, P < .001) were independent risk factors for earlier brain metastases. Median times to brain metastases were 34 and 52 months for stage 3 and 2 patients, and 30, 49, and 71 months for grade 3, 2, and 1 tumors, respectively.

Conclusions

This single-institutional case series demonstrates that TN breast cancer, higher stage, and higher histologic grade are associated with earlier brain metastases in multivariate analysis. Additional prospective studies are warranted to investigate the impact of brain metastases screening on survival outcome in this high-risk defined group.

Eribulin Efficacy on Brain Metastases in Heavily Pretreated Patients with Metastatic Breast Cancer

The onset of brain metastases (BM) is a major turning point during advanced breast cancer (ABC) evolution, with only few treatment options when local therapies have failed. The therapeutic effect of eribulin, a wildly used drug in the treatment of ABC, remains unclear in this setting. Patients and Methods: We performed a retrospective observational study to assess eribulin efficacy in patients with ABC who displayed BM at time of eribulin initiation. We collected data from the medical files of all ABC patients who received eribulin at our institution from 2012 until 2020. Our main endpoint was the central nervous system (CNS) progression-free survival. (CNS-PFS). Other evaluation criteria were extra-cranial progression free survival (PFS) and overall survival (OS). Results: Twenty patients with BM monitoring data available were selected out of the 549 who received eribulin during the inclusion period. Fifteen patients (75%) had BM progressive as the best response, three patients (15%) had disease stabilization for more than 6 months and only one patient had a partial response according to RECIST 1.1 criteria. Median CNS-PFS was 3.39 months (95CI (3.02–3.76)). Cox univariate analysis identified molecular subtype as the only prognostic parameter in our cohort, with patients with hormone-receptor positive tumors less likely to experience CNS progression than those with triple-negative MBC (HR = 0.23 (95CI = 0.07–0.80), p = 0.021). Median extra-cranial PFS was 2.67 months (95CI (2.33–3.01)). Median OS was 7.68 months (95CI (0–17.41)). Conclusion: Eribulin seems to have only a limited impact on BM evolution. Hormone receptors expression may identify a subset of patients with better BM control.

Heterogeneity and vascular permeability of breast cancer brain metastases

Improvements in the diagnosis and treatment of systemic breast cancer have led to a prolongation in patient survival. Unfortunately, these advances are also associated with an increased incidence of brain metastases (BM), with the result that many patients succumb due to BM treatment failure. Intracranial delivery of many chemotherapeutic agents and other therapeutics is hindered by the presence of an impermeable blood-brain barrier (BBB) designed to protect the brain from harmful substances. The formation of BM compromises the integrity of the BBB, resulting in a highly heterogeneous blood-tumor barrier (BTB) with varying degrees of vascular permeability. Here, we discuss how blood vessels play an important role in the formation of brain micrometastases as well as in the transformation from poorly permeable BM to highly permeable BM. We then review the role of BTB vascular permeability in the diagnostics and the choice of treatment regimens for breast cancer brain metastases (BCBM) and discuss whether the vasculature of primary breast cancers can serve as a biomarker for BM. Specifically, we examine the association between the vascular permeability of BCBM and their accumulation of large molecules such as antibodies, which remains largely unexplored.

CYP19A1 gene expression in the peripheral blood of Brazilian women with breast cancer relapse

Background

The CYP19A1 gene, which encodes the enzyme responsible for androgen aromatization into estrogens, may play an important role in breast cancer aggressiveness. However, no study has evaluated CYP19A1 gene expression in the peripheral blood of women with relapsed breast cancer.

Methods

In this cross-sectional study, CYP19A1 gene expression was quantified by RT-PCR in the peripheral blood of 146 women with breast cancer who were first divided into two groups according to the expression of CYP19A1 (low and high); each group had 73 patients. Subsequently, women were divided into two groups: those without recurrence (control, n = 85) and those with recurrence (study, n = 61). Statistical analysis of the data was performed using ANOVA, the Mann-Whitney, Chi-square or Fisher’s exact test (p <  0.05).

Results

There were no significant differences between the relative expression of CYP19A1 mRNA in the low expression group and the high expression group according to the variables studied. There were no significant differences in CYP19A1 gene expression in the study and control groups (p = 0.8461). In the relapse group, CYP19A1 gene expression was significantly higher in the hybrid luminal subtype than in the triple-negative subtype (p = 0.0321), whereas it was significantly lower in HER2-negative cases than in HER2-positive cases (p <  0.0376). Women with locoregional recurrence showed higher expression than women with distant recurrence (p <  0.0001).

Conclusions

The present study found no significant differences between women with high and low expression of the CYP19A1 gene mRNA or between those in the study group and the control group. However, in women with recurrence, there was increased expression of CYP19A1 mRNA in those who had the luminal hybrid subtype and locoregional relapse and decreased expression in those negative for HER2.

Risk factors for breast cancer brain metastases: a systematic review

Background: Brain metastasis (BM) is an increasingly common and devastating complication of breast cancer (BC).

Methods: A systematic literature search of EMBASE and MEDLINE was conducted to elucidate the current state of knowledge on known and novel prognostic factors associated with 1) the risk for BCBM and 2) the time to brain metastases (TTBM).

Results: A total of 96 studies involving institutional records from 28 countries were identified. Of these, 69 studies reported risk factors of BCBM, 46 factors associated with the TTBM and twenty studies examined variables for both outcomes. Young age, estrogen receptor negativity (ER-), overexpression of human epidermal factor (HER2+), and higher presenting stage, histological grade, tumor size, Ki67 labeling index and nodal involvement were consistently found to be independent risk factors of BCBM. Of these, triple-negative BC (TNBC) subtype, ER-, higher presenting histological grade, tumor size, and nodal involvement were also reported to associate with shorter TTBM. In contrast, young age, hormone receptor negative (HR-) status, higher presenting stage, nodal involvement and development of liver metastasis were the most important risk factors for BM in HER2-positive patients.

Conclusions: The study provides a comprehensive and individual evaluation of the risk factors that could support the design of screening tools and interventional trials for early detection of BCBM.

Treatment and outcomes in patients with central nervous system metastases from breast cancer in the real-life ESME MBC cohort

AIM

The aims of the present study were to describe treatment patterns and survival outcomes in patients with central nervous system metastases (CNSM) selected among metastatic breast cancer (MBC) patients included in a retrospective study from the Epidemiological Strategy and Medical Economics (ESME) MBC cohort.

METHODS

Neurological progression-free survival (NPFS) and overall survival (OS) were estimated using the Kaplan-Meier method. Significant contributors to NPFS were determined using a multivariate Cox proportional hazards model.

RESULTS

After a median follow-up of 42.8 months, of 16 701 patients included in the ESME MBC database, CNSM were diagnosed in 24.6% of patients. The most frequent treatments after diagnosis of CNSM were whole-brain radiotherapy (WBRT) (45.2%) and systemic treatment (59.3%). Median OS and NPFS were 7.9 months (95% CI: 7.2-8.4) and 5.5 months (95% CI: 5.2-5.8), respectively. In multivariate analysis, age >70 years (vs <50 years; HR = 1.40; 95% CI: 1.24-1.57), triple-negative tumours (vs HER2-/HR+; HR = 1.87; 95% CI: 1.71-2.06), HER2+/HR-tumours (vs HER2-/HR+; HR = 1.14; 95% CI: 1.02-1.27), ≥3 metastatic sites (vs < 3; HR = 1.32; 95% CI: 1.21-1.43) and ≥3 previous treatment lines (vs < 3; HR = 1.75; 95% CI: 1.56-1.96) were detrimental for NPFS. A time interval between selection and CNSM diagnosis superior to 18 months (vs <9 months; HR = 0.88; 95% CI: 0.78-0.98) was associated with longer NPFS.

CONCLUSIONS

This study describes current treatment patterns of MBC patients in a "real life" setting. Despite advances in stereotactic radiation therapy, most of the patients still received WBRT. More research is warranted to identify patient subsets for tailored treatment strategies.

Impact of breast cancer molecular subtypes on the incidence, kinetics and prognosis of central nervous system metastases in a large multicentre real-life cohort

BACKGROUND

Metastatic breast cancer (MBC) behaviour differs depending on hormone receptors (HR) and human epidermal growth factor receptor (HER2) statuses.

METHODS

The kinetics of central nervous system (CNS) metastases (CNS metastasis-free survival, CNSM-FS) and subsequent patient's prognosis (overall survival, OS) according to the molecular subtype were retrospectively assessed in 16703 MBC patients of the ESME nationwide multicentre MBC database (Kaplan-Meier method).

RESULTS

CNS metastases occurred in 4118 patients (24.6%) (7.2% at MBC diagnosis and 17.5% later during follow-up). Tumours were HER2-/HR+ (45.3%), HER2+/HR+ (14.5%), HER2+/HR- (14.9%) and triple negative (25.4%). Median age at CNS metastasis diagnosis was 58.1 years (range: 22.8-92.0). The median CNSM-FS was 10.8 months (95% CI: 16.5-17.9) among patients who developed CNS metastases. Molecular subtype was independently associated with CNSM-FS (HR = 3.45, 95% CI: 3.18-3.75, triple-negative and HER2-/HR+ tumours). After a 30-month follow-up, median OS after CNS metastasis diagnosis was 7.9 months (95% CI: 7.2-8.4). OS was independently associated with subtypes: median OS was 18.9 months (HR = 0.57, 95% CI: 0.50-0.64) for HER2+/HR+ , 13.1 months (HR = 0.72, 95% CI: 0.65-0.81) for HER2+/HR-, 4.4 months (HR = 1.55, 95% CI: 1.42-1.69) for triple-negative and 7.1 months for HER2-/HR+ patients (p <0.0001).

CONCLUSIONS

Tumour molecular subtypes strongly impact incidence, kinetics and prognosis of CNS metastases in MBC patients.

CLINICAL TRIAL REGISTRATION

NCT03275311.

The evolving role of trastuzumab emtansine (T-DM1) in HER2-positive breast cancer with brain metastases

Approximately 30-50% of advanced human epidermal growth factor receptor 2 (HER2) positive breast cancer patients will develop brain metastases (BMs) during the disease course. Brain metastases may become a main limitation of life expectancy and a half of them will die from brain progression. Even in patients with early HER2-positive breast cancer managed with curative therapy, the risk of brain metastases is also increased. Central nervous system (CNS) may usually present as the first site of recurrence in HER2-positive breast cancer. Local treatments including radiotherapy and surgery are essential while new chemotherapy and biological agents appear to contribute a significant role in the future treatment field of CNS metastases. This article will review recent progresses in HER2-positive breast cancer with BM, with a focus on the efficacy of the HER2 targeted agents-trastuzumab emtansine (T-DM1).

Breast cancer subtype and intracranial recurrence patterns after brain-directed radiation for brain metastases

PURPOSE

Brain metastases from breast cancer are frequently managed with brain-directed radiation but the impact of subtype on intracranial recurrence patterns after radiation has not been well-described. We investigated intracranial recurrence patterns of brain metastases from breast cancer after brain-directed radiation to facilitate subtype-specific management paradigms.

METHODS

We retrospectively analyzed 349 patients with newly diagnosed brain metastases from breast cancer treated with brain-directed radiation at Brigham and Women's Hospital/Dana-Farber Cancer Institute between 2000 and 2015. Patients were stratified by subtype: hormone receptor-positive/human epidermal growth factor receptor 2-negative (HR+/HER2-), HER2+ positive (HER2+), or triple-negative breast cancer (TNBC). A per-metastasis assessment was conducted. Time-to-event analyses were conducted using multivariable Cox regression.

RESULTS

Of the 349 patients, 116 had HR+/HER2- subtype, 164 had HER2+ subtype, and 69 harbored TNBC. Relative to HR+/HER2- subtype, local recurrence was greater in HER2+ metastases (HR 3.20, 95% CI 1.78-5.75, p < 0.001), while patients with TNBC demonstrated higher rates of new brain metastases after initial treatment (HR 3.16, 95% CI 1.99-5.02, p < 0.001) and shorter time to salvage whole brain radiation (WBRT) (HR 3.79, 95% CI 1.36-10.56, p = 0.01) and salvage stereotactic radiation (HR 1.86, 95% CI 1.11-3.10, p = 0.02).

CONCLUSIONS

We identified a strong association between breast cancer subtype and intracranial recurrence patterns after brain-directed radiation, particularly local progression for HER2+ and distant progression for TNBC patients. If validated, the poorer local control in HER2+ brain metastases may support evaluation of novel local therapy-based approaches, while the increased distant recurrence in TNBC suggests the need for improved systemic therapy and earlier utilization of WBRT.

Prediction of postoperative disease-free survival and brain metastasis for HER2-positive breast cancer patients treated with neoadjuvant chemotherapy plus trastuzumab using a machine learning algorithm

PURPOSE

This study aimed to develop mathematical tools to predict the likelihood of recurrence after neoadjuvant chemotherapy (NAC) plus trastuzumab in patients with human epidermal growth factor receptor 2 (HER2)-positive breast cancer.

METHODS

Data of 776 patients from a multicenter retrospective cohort study were collected. All patients had HER2-positive breast cancer and received NAC plus trastuzumab between 2001 and 2010. Two mathematical tools using a machine learning method were developed to predict the likelihood of disease-free survival (DFS) (DFS model) and brain metastasis (BM) (BM model) within 5 years after surgery. For validation, bootstrap analyses were conducted. The area under the receiver operating characteristics curve (AUC) was calculated to examine the discrimination.

RESULTS

The AUC values were 0.785 (95% CI 0.740-0.831, P < 0.001) for the DFS model and 0.871 (95% CI 0.830-0.912, P < 0.001) for the BM model. Patients with low-risk DFS or BM events, as predicted by the models, showed better 5-year DFS and BM rates than those with high-risk DFS or BM events (89% vs. 61% for the DFS model, P < 0.001; 99% vs. 87% for the BM model, P < 0.001). These models maintained discrimination abilities in both luminal and non-luminal subtypes, providing prognostic information independent of pathological response. Bootstrap validation confirmed the high generalization abilities of the models.

CONCLUSIONS

The DFS and BM models have a high accuracy to predict prognosis among HER2-positive patients treated with NAC plus trastuzumab. Our models can help optimize adjuvant therapy and postoperative surveillance.

Clinicopathological and Treatment-Associated Prognostic Factors in Patients with Breast Cancer Leptomeningeal Metastases in Relation to Tumor Biology

BACKGROUND

Breast cancer (BC) is one of the solid tumors most commonly associated with leptomeningeal disease (LMD). LMD carries a devastating prognosis; however, disease presentation and prognostic factors are uncertain.

SUBJECTS, MATERIALS, AND METHODS

In order to describe patient characteristics, treatment patterns, and factors associated with survival in a contemporary multicentric cohort, 153 consecutive BC patients diagnosed with LMD at two European institutions (2002-2017) were included. Time to LMD and overall survival (OS) after LMD diagnosis were evaluated using the Kaplan-Meier method and Cox proportional hazards models.

RESULTS

Median age at LMD diagnosis was 58 years (25-84). Tumor phenotype distribution was as follows: hormone receptor (HR) positive (HR+)/human epidermal growth receptor 2 (HER2) negative 51.0%, triple-negative 15.0%, HR+/HER2 positive (HER2+) 13.1% and HR negative/HER2+ 7.2%. Most patients received active anticancer treatments (radiation therapy [RT] n = 42, systemic therapy n = 110, intrathecal treatment n = 103).Median OS was 3.9 months (95% confidence interval [CI] 2.4-5.5). Eastern Cooperative Oncology Group performance status (ECOG PS) >2, high white blood cells count, low glucose, and high protein in cerebrospinal fluid (CSF) were poor prognostic factors. Having received RT or systemic treatment was associated with better prognosis. In multivariate analysis, ECOG PS (hazard ratio 2.22, 95% CI 1.25-3.94), CSF glucose levels (hazard ratio 1.74, 95% CI 1.05-2.88), and having received systemic treatment (hazard ratio 0.17, 95% CI 0.09-0.32) were confirmed as independent prognostic factors. In HER2+ BC patients, having received systemic HER2-targeted therapy was the only factor maintaining independent prognostication (hazard ratio 0.12, 95% CI 0.02-0.67) in multivariate analysis.

CONCLUSION

Despite being limited by their retrospective nature, these results highlight the need for clinical trials in BC LMD, stratified on tumor biology.

IMPLICATIONS FOR PRACTICE

Leptomeningeal disease (LMD) is a devastating complication of breast cancer (BC), and its optimal therapy is still not defined. Here, patient characteristics, treatment patterns, and prognostic factors from a contemporary cohort of 153 BC-related LMD patients are reported. In multivariate analysis, Eastern Cooperative Oncology Group performance status, cerebrospinal fluid glucose levels, and having received systemic treatment were confirmed as independent prognostic factors in the overall population, whereas in human epidermal growth receptor 2 (HER2) positive BC patients, having received systemic HER2-targeted therapy was the only factor maintaining independent prognostication in multivariate analysis. These results highlight the need to consider stratification on tumor biology in the treatment of BC LMD.