Increased rate of brain metastasis with trastuzumab therapy not associated with impaired survival

Systemic Treatment for Brain Metastasis and Leptomeningeal Disease in Breast Cancer Patients

PURPOSE OF REVIEW

Breast cancer with brain metastasis (BCBM) and leptomeningeal disease (LMD) are important clinical problems. Traditionally, patients with metastases to the brain and meninges were excluded from clinical trials; hence, robust, evidence-based treatment recommendations are lacking. In this review, we outline the systemic treatment options and ongoing clinical trials.

RECENT FINDINGS

Several recent studies have added to the systemic treatment options available. Antibody-drug conjugates have changed the therapeutic landscape. Combination treatment modalities that target multiple mechanisms including disruption of the blood brain barrier are increasingly being studied. Breast cancer with brain metastases and LMD is a heterogenous disease. While the prognosis remains grim, with more systemic treatment options, patients with BCBM are now living longer. Many ongoing clinical trials hold promise to further improve outcomes.

Incidence of HER2-expressing brain metastases in patients with HER2-null breast cancer: a matched case analysis

The HER2-directed antibody-drug conjugate trastuzumab deruxtecan is active against lower levels of HER2 expression than prior-generation therapies. The rate of HER2 expression in brain metastases among patients with initially HER2-null breast cancer is undefined, and receptor discordance in advanced breast cancer with brain metastases may underestimate CNS response potential in the absence of brain metastasis sampling. In this cohort study including 136 patients with 401 samples scored according to ASCO/CAP guidelines, 15/28 patients (54%) with HER2-null primary breast cancer have detectable HER2 expression in subsequently resected brain metastases, a significant discordant population.

Navigating the Blood-Brain Barrier: Challenges and Therapeutic Strategies in Breast Cancer Brain Metastases

Breast cancer (BC) is the most common cancer in women, with metastatic BC being responsible for the highest number of deaths. A frequent site for BC metastasis is the brain. Brain metastasis derived from BC involves the cooperation of multiple genetic, epigenetic, angiogenic, and tumor-stroma interactions. Most of these interactions provide a unique opportunity for development of new therapeutic targets. Potentially targetable signaling pathways are Notch, Wnt, and the epidermal growth factor receptors signaling pathways, all of which are linked to driving BC brain metastasis (BCBM). However, a major challenge in treating brain metastasis remains the blood-brain barrier (BBB). This barrier restricts the access of unwanted molecules, cells, and targeted therapies to the brain parenchyma. Moreover, current therapies to treat brain metastases, such as stereotactic radiosurgery and whole-brain radiotherapy, have limited efficacy. Promising new drugs like phosphatase and kinase modulators, as well as BBB disruptors and immunotherapeutic strategies, have shown the potential to ease the disease in preclinical studies, but remain limited by multiple resistance mechanisms. This review summarizes some of the current understanding of the mechanisms involved in BC brain metastasis and highlights current challenges as well as opportunities in strategic designs of potentially successful future therapies.

Leveraging Molecular and Immune-Based Therapies in Leptomeningeal Metastases

Leptomeningeal metastases represent an aggressive stage of cancer with few durable treatment options. Improved understanding of cancer biology, neoplastic reliance on oncogenic driver mutations, and complex immune system interactions have resulted in an explosion in cancer-directed therapy in the last two decades to include small molecule inhibitors and immune checkpoint inhibitors. Most of these therapeutics are underexplored in patients with leptomeningeal metastases, limiting extrapolation of extracranial and even intracranial efficacy outcomes to the unique leptomeningeal space. Further confounding our interpretation of drug activity in the leptomeninges is an incomplete understanding of drug penetration through the blood-cerebrospinal fluid barrier of the choroid plexus. Nevertheless, a number of retrospective studies and promising prospective trials provide evidence of leptomeningeal activity of several small molecule and immune checkpoint inhibitors and underscore potential areas of further therapeutic development for patients harboring leptomeningeal disease.

Leptomeningeal Metastases: New Opportunities in the Modern Era

Leptomeningeal metastases arise from cancer cell entry into the subarachnoid space, inflicting significant neurologic morbidity and mortality across a wide range of malignancies. The modern era of cancer therapeutics has seen an explosion of molecular-targeting agents and immune-mediated strategies for patients with breast, lung, and melanoma malignancies, with meaningful extracranial disease control and improvement in patient survival. However, the clinical efficacy of these agents in those with leptomeningeal metastases remains understudied, due to the relative rarity of this patient population, the investigational challenges associated with studying this dynamic disease state, and brisk disease pace. Nevertheless, retrospective studies, post hoc analyses, and small prospective trials in the last two decades provide a glimmer of hope for patients with leptomeningeal metastases, suggesting that several cancer-directed strategies are not only active in the intrathecal space but also improve survival against historical odds. The continued development of clinical trials devoted to patients with leptomeningeal metastases is critical to establish robust efficacy outcomes in this patient population, define drug pharmacokinetics in the intrathecal space, and uncover new avenues for treatment in the face of leptomeningeal therapeutic resistance.

Targeted Drug Delivery to the Central Nervous System Using Extracellular Vesicles

The blood brain barrier (BBB) maintains the homeostasis of the central nervous system (CNS) and protects the brain from toxic substances present in the circulating blood. However, the impermeability of the BBB to drugs is a hurdle for CNS drug development, which hinders the distribution of the most therapeutic molecules into the brain. Therefore, scientists have been striving to develop safe and effective technologies to advance drug penetration into the CNS with higher targeting properties and lower off-targeting side effects. This review will discuss the limitation of artificial nanomedicine in CNS drug delivery and the use of natural extracellular vesicles (EVs), as therapeutic vehicles to achieve targeted delivery to the CNS. Information on clinical trials regarding CNS targeted drug delivery using EVs is very limited. Thus, this review will also briefly highlight the recent clinical studies on targeted drug delivery in the peripheral nervous system to shed light on potential strategies for CNS drug delivery. Different technologies engaged in pre- and post-isolation have been implemented to further utilize and optimize the natural property of EVs. EVs from various sources have also been applied in the engineering of EVs for CNS targeted drug delivery in vitro and in vivo. Here, the future feasibility of those studies in clinic will be discussed.

The incidence of brain metastases among patients with metastatic breast cancer: a systematic review and meta-analysis

BACKGROUND

Patients with metastatic breast cancer (MBC) are living longer, but the development of brain metastases often limits their survival. We conducted a systematic review and meta-analysis to determine the incidence of brain metastases in this patient population.

METHODS

Articles published from January 2000 to January 2020 were compiled from four databases using search terms related to breast cancer, brain metastasis, and incidence. The overall and per patient-year incidence of brain metastases were extracted from studies including patients with human epidermal growth factor receptor-2 positive (HER2+), triple negative, and hormone receptor (HR)+/hormone receptor negative (HER2-) MBC; pooled overall estimates for incidence were calculated using random effects models.

RESULTS

937 articles were compiled, and 25 were included in the meta-analysis. Incidence of brain metastases in patients with HER2+ MBC, triple negative MBC, and HR+/HER2- MBC was reported in 17, 6, and 4 studies, respectively. The pooled cumulative incidence of brain metastases was 31% for the HER2+ subgroup (median follow-up: 30.7 months, IQR: 24.0-34.0), 32% for the triple negative subgroup (median follow-up: 32.8 months, IQR: 18.5-40.6), and 15% among patients with HR+/HER2- MBC (median follow-up: 33.0 months, IQR: 31.9-36.2). The corresponding incidences per patient-year were 0.13 (95% CI: 0.10-0.16) for the HER2+ subgroup, 0.13 (95%CI: 0.09-0.20) for the triple negative subgroup, and only 0.05 (95%CI: 0.03-0.08) for patients with HR+/HER2- MBC.

CONCLUSION

There is a high incidence of brain metastases among patients with HER2+ and triple negative MBC. The utility of a brain metastases screening program warrants investigation in these populations.

Incidence of central nervous system metastases in patients with human epidermal growth factor receptor 2-positive metastatic breast cancer treated with trastuzumab: A meta-analysis

This study aimed to estimate the incidence of central nervous system (CNS) metastases in patients with human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer (MBC) treated with trastuzumab. Studies were identified through a literature search of electronic databases. Random-effects meta-analyses were performed to estimate the incidence rate of CNS metastases, trastuzumab therapy duration, and time from trastuzumab therapy to CNS metastasis diagnosis. A meta-analysis of odds ratios was performed to evaluate the significance of a difference in CNS metastasis incidence between patients with and without trastuzumab treatment. Thirty studies (8121 trastuzumab-treated and 3972 control patients) were included. The follow-up duration was 18.9 months (95% confidence interval [CI]: 13.8, 24.1). The trastuzumab treatment duration was 9.0 months (95% CI: 7.0, 11.0). The median interval between the start of trastuzumab therapy and CNS metastasis diagnosis was 12.2 months (95% CI: 9.5, 14.7). The incidence of CNS metastasis after the start of trastuzumab therapy was 22% (95% CI: 16, 27). The incidence of CNS metastases was significantly higher in trastuzumab-treated than in non-trastuzumab-treated patients (odds ratio: 1.39 [95% CI: 1.06, 1.82], p=0.02). The survival time from the start of the study was 23.4 months (95% CI: 19.7, 27.1) in trastuzumab-treated patients and 18.4 months (95% CI: 12.7, 24.1) in patients treated with control regimens. The survival time after the development of CNS metastases in trastuzumab-treated patients was 19.2 months (95% CI: 15.6, 25.9). Approximately 22% of patients with HER2-positive MBC who were treated with trastuzumab developed CNS metastases. However, trastuzumab-treated patients had a longer survival than patients who were not treated with trastuzumab.

Lapatinib Plus Local Radiation Therapy for Brain Metastases From HER-2 Positive Breast Cancer Patients and Role of Trastuzumab: A Systematic Review and Meta-Analysis

Background

Intracranial activity of lapatinib has been demonstrated in several studies in patients with human epidermal growth factor receptor-2 positive breast cancers (HER-2+ BC). Stereotactic radiosurgery (SRS) has been increasingly used as the local therapy for brain metastases in breast cancer patients. Increased objective response rate was observed for lapatinib plus whole brain radiotherapy (WBRT) is such patients with high toxicity.

Objective

We seek to obtain clinical evidence of synergistic efficacy of lapatinib in combination with radiation therapy, in particular, SRS.

Materials and methods

We carried out a comprehensive research using the following databases: PubMed; Medline; EMBASE; Cochrane library. These databases were searched until 10 June 2020. PRISMA guidelines were followed step by step for carrying out this systematic review and meta-analysis. Review Manager v 5.4 software was used for statistical evaluation of data.

Results

Overall 6 studies with 843 HER-2 positive breast cancer patients (442 HER-2 amplified disease, 399 luminal B disease) were included in this systematic review and meta-analysis. A total 279 patients had received lapatinib in addition to HER-2 antibody (trastuzumab) plus/minus chemoradiotherapy, while 610 patients had received trastuzumab-based management or only chemoradiotherapy. Lapatinib-based management of BM was associated with significant increase in overall survival (HR 0.63 [0.52, 0.77], p < 0.00001). Combination of the two (trastuzumab plus lapatinib) was associated with increased survival advantage compared to each agent alone (0.55 [0.32, 0.92], p = 0.02). SRS in combination with lapatinib was associated with increased local control (HR 0.47 [0.33, 0.66], p = 0.0001). Ever use of lapatinib with SRS was associated an increased survival as reported in two studies (Shireen et al.: 27.3 vs. 19.5 months, p = 0.03; Kim et al.: 33.3 vs. 23.6 months, p = 0.009). Kim et al. also revealed significant increase in intracranial activity with concurrent lapatinib reporting 57% complete response compared to 38% (p < 0.001) and lower progressive disease rate of 11 vs. 19% (p < 0.001). Risk of radiation necrosis was decreased with lapatinib use.

Conclusions

Lapatinib has shown intracranial activity and yielded better survival for HER-2+ BC patients with BMs. SRS in combination with ever use of lapatinib had better local control and were associated with better survival. Radiation necrosis risk was reduced with the use of lapatinib.

Breast cancer brain metastases: Molecular subtype, treatment and survival

BACKGROUND

No clear guidelines exist for management of breast cancer brain metastases (BCBM).

OBJECTIVE

We assessed the relationship between patient and tumor characteristics, treatment, and overall survival (OS).

METHODS

We conducted a retrospective review of 196 patients who received brain radiation for BCBM between 2009-2013 at Mayo Clinic. Primary tumor characteristics were collected, including simplified molecular subtype. Other characteristics included patient's ECOG, number of brain lesions at BCBM diagnosis, and treatment received, including neurosurgery, whole-brain radiation therapy (WBRT), and stereotactic radiosurgery (SRS). The primary endpoint was OS from time of BCBM diagnosis.

RESULTS

Single-variable analysis revealed patients with HER2+ breast cancer had improved OS (HR = 0.6, p = 0.008). Compared to patients with 1-3 brain lesions, the risk of death in patients with leptomeningeal disease was 2.5-fold higher (p = 0.003). Worsening ECOG status was associated with worsening OS. Patients who received SRS and WBRT had improved OS (HR = 0.37, p < 0.001) compared to patients receiving WBRT alone.

CONCLUSIONS

Patients with the best OS had an ECOG of 0, HER2+ disease, and 1-3 brain lesions. The best OS was associated with the combination of neurosurgery and radiation therapy. A comprehensive treatment plan including neurosurgical evaluation and radiation therapy should be considered for patients with BCBM.

A Retrospective Study on the Efficacy of Trastuzumab in HER2-Positive and Tamoxifen-Refractory Breast Cancer with Brain Metastasis

BACKGROUND AND OBJECTIVE

The role of trastuzumab in breast cancer with brain metastasis is still in discussion. This study was conducted to investigate the efficacy of trastuzumab in the management of human epidermal growth factor receptor 2 (HER2)-positive, tamoxifen-refractory breast cancer with brain metastasis.

METHODS

This retrospective study was conducted between January 2008 and December 2012. A total of 33 patients receiving trastuzumab treatment for HER2-positive, tamoxifen-refractory breast cancer with brain metastasis were assigned to the experimental group, while a matched group of 35 patients who received systemic therapy without trastuzumab were assigned to the control group. Data on the patient characteristics and clinical outcomes were collected and evaluated.

RESULTS

Patients in the trastuzumab group showed a significantly better response to treatment than those in the control group (p = 0.025). Univariate and multivariate Cox proportional regression analyses indicated that progression-free survival was significantly longer in patients receiving trastuzumab therapy than in the control group (hazard ratio [HR] 2.213 [p = 0.003] and HR 3.056 [p < 0.001], respectively) and significantly shorter in patients with two or more extracranial metastases (HR 0.417 [p = 0.002] and HR 0.317 [p < 0.001], respectively). Furthermore, patients on trastuzumab treatment experienced longer overall survival than patients in the control group (HR 2.844 [p < 0.001] and HR 4.017 [p < 0.001], respectively), while shorter overall survival was seen in patients with two or more extracranial metastases (HR 0.524 [p = 0.021] and HR 0.430 [p = 0.005], respectively) and in those receiving capecitabine-based therapy as compared with anthracycline-based therapy (HR 0.558 [p = 0.030] and HR 0.449 [p = 0.011], respectively).

CONCLUSION

Trastuzumab was found to benefit patients with HER2-positive, tamoxifen-refractory breast cancer with brain metastasis by improving progression-free and overall survival.

Prevalence of bone metastases and bone-targeting agent use among solid tumor patients in the United States

Purpose

Patients with bone metastases are at an increased risk of experiencing morbidity due to bone complications, and bone-targeting agents (BTA) are indicated for the prevention of these complications. Population-based estimates of the prevalence of bone metastases associated with solid tumors, and current treatment patterns for these patients, are limited. This study was undertaken to estimate the prevalence of bone metastases from solid tumors and to describe recent trends in the use of BTA in the US.

Methods

We estimated the prevalence of bone metastases in the US in 2012 using data from Medicare fee-for-service and PharMetrics Plus, a large commercial claims database. We evaluated the proportion of patients with bone metastases who were treated with BTA in 2012, timing of initiation of BTA relative to bone metastasis diagnosis, and persistence on BTA, overall and by primary tumor type and treatment.

Results

There were ~330,000 (168,063 Medicare fee-for-service; 162,239 other) patients aged ≥18 years living with solid tumors and bone metastases in 2012. BTA were used by 43% (Commercial) to 47% (Medicare) of patients in 2012, with the greatest use among breast cancer patients. Over half (Medicare: 57%; Commercial: 53%) of BTA-treated patients initiated BTA after experiencing a bone complication.

Conclusion

Of the estimated 330,000 solid tumor patients living with bone metastases in the US in 2012, many may have received less than optimal care to prevent bone complications during the calendar year.

Pertuzumab, trastuzumab and docetaxel reduced the recurrence of brain metastasis from breast cancer: a case report

The CLEOPATRA trial reported the survival benefit of pertuzumab with trastuzumab plus docetaxel in HER2-positive metastatic breast cancer patients. However, there are a few case reports concerning the effects of a pertuzumab-containing regimen on brain metastases. A 55-year-old woman, who underwent curative surgery for breast cancer after neoadjuvant chemotherapy 5 years previously, developed repeated solitary brain metastasis in her right occipital lobe. Whole brain radiation therapy, stereotactic radiosurgery and 3 times of surgical resection were performed. Lapatinib and capecitabine plus tamoxifen were administered. The metastasis recurred in the stump of the previous surgery. Pertuzumab with trastuzumab plus docetaxel was initiated as second-line chemotherapy. A complete response of the brain metastasis was achieved, which persisted for 5 months. Pertuzumab with trastuzumab plus docetaxel was effective in reducing the brain metastases from breast cancer. Further studies are warranted to confirm the effect of this regimen on brain metastases.

Treatment of leptomeningeal carcinomatosis: current challenges and future opportunities

Leptomeningeal metastasis (LM) in breast cancer patients confers a uniformly poor prognosis and decreased quality of life. Treatment options are limited and often ineffective, due in large part to limitations imposed by the blood-brain barrier and the very aggressive nature of this disease. The majority of studies investigating the treatment of LM are not specific to site of origin. Conducting randomized, disease-specific clinical trials in LM is challenging, and much clinical outcomes data are based on case reports or retrospective case series. Multiple studies have suggested that chemo-radiotherapy is superior to either chemotherapy or radiation therapy alone. Attempts to overcome current obstacles in the treatment of breast cancer LM hold promise for the future. We review the epidemiology, diagnosis, and prognosis of LM in breast cancer, and discuss the treatment options currently available as well as those under investigation.

Risk factors and survival outcome in cerebral metastatic breast cancer

The development of brain metastases (BM) of primary breast cancer patients leads to limited survival. HER2-positive and triple-negative status are risk factors for the development of BM. Estrogen receptor (ER)/progesterone receptor (PR)/HER2 are important prognostic markers and are essential for effective treatment decisions. We retrospectively analyzed the impact of known risk factors and the outcome after the development of BM. Eighty consecutive patients, treated between January 1, 2001, and June 30, 2012, on the basis of primary non-metastatic operable breast cancer and who developed BM, were enrolled. Clinical parameters (TNM; ER, PR, HER2) and their impact on the occurrence of BM and additionally their prognostic influence after the occurrence of BM were investigated. A small tumor size, ductal histology, grade 3, hormone receptor-negative, triple-negative and HER2+ tumors were associated with BM. Median time from breast cancer diagnosis to BM was 35 months (range 26.2-43.8). Grade 3 versus 2 has significantly negative prognostic impact with earlier development of BM (median 23 vs. 41 months; p=0.033). HER2-positive patients had significantly longer survival after the occurrence of BM than HER2-negative patients (p=0.009). The risk of BM varies significantly by subtype. In high-risk patients, the occurrence of BM must be considered, and possibly, general screening in these patients is warranted. The survival advantage of HER2-positive breast cancer patients compared with HER2-negative patients after the occurrence of BM is possibly explainable by systemic control of disease. Standard of care for patients with BM is whole-brain radiotherapy, with/without surgery, or stereotactic radiosurgery. Perhaps novel therapies may additionally improve survival in these patients.

Brain metastases of breast cancer

Brain metastases of breast cancer remain a difficult problem for clinical management. Their incidence appears to be increasing, which is likely due to longer survival times for advanced breast cancer patients as well as additional and improved tools for detection. Molecular features of tumors associated with this syndrome are not yet understood. In general, survival may be improving for brain metastases due to better local control in the CNS, as well as improvements in systemic disease management. Selected patients with brain metastases are able to undergo surgical resection, which has been associated with extended disease control in some patients. However, whole-brain radiation has been the mainstay for treatment for most patients. Stereotactic radiosurgery is playing an increasing role in the primary treatment of brain metastases, as well as for salvage after whole-brain radiation. Recent series have reported median survivals of 13 months or longer with stereotactic radiosurgery. Further improvements in radiation-based approaches may come from ongoing studies of radiosensitizing agents. The ability of systemic treatments to impact brain metastases has been debated, and specific treatment regimens have yet to be defined. New approaches include chemotherapy combinations, biologic therapies and novel drug-delivery strategies.

Brain metastases in HER2-positive metastatic breast cancer patients who received chemotherapy with or without trastuzumab

OBJECTIVE

The aim of this study was to assess whether trastuzumab usage is a risk factor for the development of brain metastasis (BM) in human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer (MBC) and factors affecting survival after development of BM.

MATERIALS AND METHODS

One hundred thirty-two patients treated with (treatment group) or without trastuzumab (control group) with brain metastasis were retrospectively analyzed.

RESULTS

Ninety of the 132 HER2-positive MBC patients were in the treatment group and 42 were in the control group. BM was significantly increased in patients who were treated with trastuzumab in two or more lines (58.5 vs 24.1 %, p < 0.001). Trastuzumab and lapatinib usage after BM and age were independent prognostic factors for overall survival in univariate and multivariate analysis.

CONCLUSION

The risk for BM was increased in patients who were treated with trastuzumab in two or more lines. Using trastuzumab and lapatinib after BM and age were independent prognostic factors for time to death from BM.

Molecular interactions in the development of brain metastases

Brain metastases are a much-feared complication of cancer. The development of brain metastases requires a malignant cell to acquire characteristics that facilitate dissemination away from the primary site, entrance into the nervous system, and establishment in the brain. This review summarizes recent work focused on the molecular derangements leading to brain metastases and outlines areas in need of greater understanding.

SRC family kinases as novel therapeutic targets to treat breast cancer brain metastases

Despite better control of early-stage disease and improved overall survival of patients with breast cancer, the incidence of life-threatening brain metastases continues to increase in some of these patients. Unfortunately, other than palliative treatments there is no effective therapy for this condition. In this study, we reveal a critical role for Src activation in promoting brain metastasis in a preclinical model of breast cancer and we show how Src-targeting combinatorial regimens can treat HER2(+) brain metastases in this model. We found that Src was hyperactivated in brain-seeking breast cancer cells derived from human cell lines or from patients' brain metastases. Mechanistically, Src activation promoted tumor cell extravasation into the brain parenchyma via permeabilization of the blood-brain barrier. When combined with the EGFR/HER2 dual-targeting drug lapatinib, an Src-targeting combinatorial regimen prevented outgrowth of disseminated breast cancer cells through the induction of cell-cycle arrest. More importantly, this combinatorial regimen inhibited the outgrowth of established experimental brain metastases, prolonging the survival of metastases-bearing mice. Our results provide a rationale for clinical evaluation of Src-targeting regimens to treat patients with breast cancer suffering from brain metastasis.

Survival following gamma knife radiosurgery for brain metastasis from breast cancer

Background

Breast cancer is the second most common cause of brain metastases in the United States. Although breast cancer induced brain metastases represent an incurable condition, some patients experience prolonged survival. In this retrospective study, we examine a cohort of patients with brain metastases from breast cancer treated with Gamma Knife stereotactic radiosurgery to identify factors that predict better outcomes.

Methods

A retrospective database of 100 patients treated for brain metastases due to breast cancer via Gamma Knife radiosurgery (GKS) from July 1998 through March 2009 was reviewed. Patients who received radiosurgery as sole treatment, as a planned boost after whole brain radiotherapy or surgical resection, or as salvage after prior whole brain radiation therapy (WBRT) or surgical resection were included. Prognostic factors identified to be significant for survival in previous brain metastasis studies were analyzed for significance by univariate and multivariate Cox analysis.

Results

Overall, the median brain progression-free survival time was 7.1 months and the median survival time was 12.3 months. No prognostic variables were significant for brain progression-free survival. For patients treated with a planned GKS after WBRT, GKS as sole treatment, GKS salvage after WBRT, GKS boost after surgery, or GKS for surgical salvage the median survival times (MSTs) were as follows: 12.2 months, 12.4 months, 9.5 months, 27.6 months and 33.4 months respectively. Differences between the groups were not significant (p = 0.06); however, GKS boost after surgery and GKS for salvage after surgery did have a trend toward better overall survival.

The MST for patients of age <65 years was 14.5 months, compared to age ≥65 which was 7.7 months (p = 0.06) and remained a significant prognostic factor for overall survival on multivariate analysis. The MST for patients with a single lesion was 16.9 months, not significantly different than the MST of 14.5 months for patients with 2–3 lesions. However patients with >3 lesions had a MST of 5.9 months, which was significantly worse. Breast cancer subtype as approximated by biomarkers and KPS were not significant predictors of overall survival and stage at initial diagnosis was inversely associated with survival.

Conclusion

Stereotactic radiosurgery offers good local control and prolonged survival in selected patients. Age and number of lesions are strong predictors of overall survival.

Optimal management of brain metastases from breast cancer. Issues and considerations

The incidence of brain metastases (BM) in breast cancer patients has increased over the last decade, presumably due to advances in systemic treatment. Today, breast cancer is the second most common cause of BM among all solid malignancies, second only to lung cancer; furthermore, it is the most common cause of leptomeningeal carcinomatosis. The HER2-positive subtype was consistently shown to have a higher risk for BM as compared with HER2-negative disease. More recently, however, it was shown that a similar incidence exists in triple-negative tumours. Local treatment options, radiotherapy and neurosurgical resection, remain the mainstay of therapy for BM. While some studies have suggested a direct effect of conventional chemotherapy on BM, the main beneficial aspect of systemic treatment is rather due to control of non-CNS systemic disease. Importantly, in patients with HER2-positive breast cancer receiving HER2-targeted therapy after local treatment for BM, superior survival outcomes were reported. Leptomeningeal carcinomatosis has a dismal prognosis. Survival with whole brain radiotherapy alone remains short and the potential additional benefit of intrathecal chemotherapy is still disputed. According to case reports, intrathecal administration of trastuzumab appears to be a promising strategy in patients with HER2-positive leptomeningeal carcinomatosis. In conclusion, while the outcome of breast cancer patients with BM has improved especially in the HER2-positive subtype, the prognosis for the majority of patients remains poor. Therefore, development of novel systemic treatment options offering activity within the brain is urgently warranted. Novel insights into the pathobiology of BM formation may offer the possibility for targeted drug prophylaxis of CNS involvement in high-risk patients.

Emerging treatment options for the management of brain metastases in patients with HER2-positive metastatic breast cancer

The widespread use of trastuzumab in the past decade has led to a significant and measureable improvement in the survival of patients with human epidermal growth factor receptor-2 (HER2) overexpressing breast cancer, and in many ways has redefined the natural history of this aggressive breast cancer subtype. Historically, survival in patients with HER2-positive disease was dictated by the systemic disease course, and what appears to be the central nervous system (CNS) tropism associated with HER2-amplified tumors was not clinically evident. With improved systemic control and prolonged survival, the incidence of brain metastases has increased, and CNS disease, often in the setting of well-controlled extracranial disease, is proving to be an increasingly important and clinically challenging cause of morbidity and mortality in patients with HER2-positive advanced breast cancer. This review summarizes the known clinical data for the systemic treatment of HER2-positive CNS metastases and includes information about ongoing clinical trials of novel therapies as well as emerging strategies for early detection and prevention.

Systemic treatment of brain metastases in HER2-positive breast cancer: current status and future directions

In recent years, brain metastases have emerged as a main challenge affecting the morbidity and mortality of patients with HER2-positive metastatic breast cancer. In the era following trastuzumab, approximately 30% of these patients develop brain metastases. Trastuzumab does not cross the blood-brain barrier, hence its role is limited to controlling extra-CNS metastases. Lapatinib emerged as a potential candidate; however, its use as a single agent was associated with modest responses. Combination with capecitabine was associated with good results, particularly in patients with newly diagnosed brain metastases. In this article, we discuss the role of trastuzumab and lapatinib in patients with HER2-positive breast cancer with brain metastases. We also highlight the complex structure of the blood-brain barrier and elucidate different potential strategies that could be useful in improving drug delivery.

Correlation between quantitative HER-2 protein expression and risk for brain metastases in HER-2+ advanced breast cancer patients receiving trastuzumab-containing therapy

BACKGROUND

Patients with human epidermal growth factor receptor (HER)-2+ breast cancer are at particularly high risk for brain metastases; however, the biological basis is not fully understood. Using a novel HER-2 assay, we investigated the correlation between quantitative HER-2 expression in primary breast cancers and the time to brain metastasis (TTBM) in HER-2+ advanced breast cancer patients treated with trastuzumab.

METHODS

The study group included 142 consecutive patients who were administered trastuzumab-based therapy for HER-2+ metastatic breast cancer. HER-2/neu gene copy number was quantified as the HER-2/centromeric probe for chromosome 17 (CEP17) ratio by central laboratory fluorescence in situ hybridization (FISH). HER-2 protein was quantified as total HER-2 protein expression (H2T) by the HERmark® assay (Monogram Biosciences, Inc., South San Francisco, CA) in formalin-fixed, paraffin-embedded tumor samples. HER-2 variables were correlated with clinical features and TTBM was measured from the initiation of trastuzumab-containing therapy.

RESULTS

A higher H2T level (continuous variable) was correlated with shorter TTBM, whereas HER-2 amplification by FISH and a continuous HER-2/CEP17 ratio were not predictive (p = .013, .28, and .25, respectively). In the subset of patients that was centrally determined by FISH to be HER-2+, an above-the-median H2T level was significantly associated with a shorter TTBM (hazard ratio, [HR], 2.4; p = .005), whereas this was not true for the median HER-2/CEP17 ratio by FISH (p = .4). Correlation between a continuous H2T level and TTBM was confirmed on multivariate analysis (HR, 3.3; p = .024).

CONCLUSIONS

These data reveal a strong relationship between the quantitative HER-2 protein expression level and the risk for brain relapse in HER-2+ advanced breast cancer patients. Consequently, quantitative assessment of HER-2 protein expression may inform and facilitate refinements in therapeutic treatment strategies for selected subpopulations of patients in this group.

Impact of anti-HER2 therapy on overall survival in HER2-overexpressing breast cancer patients with brain metastases

Background:

Trastuzumab-based therapy after diagnosis of brain metastases (BM) may improve survival due to prolonged systemic disease control. We investigated whether lapatinib may yield additional survival benefit.

Methods:

Eighty patients with BM from HER2-positive breast cancer were identified. Karnofsky Performance Score (KPS) of at least 70 was required. We included a control group of 37 patients treated before 2003, when continuation of trastuzumab after diagnosis of BM was not yet recommended. Remainders received either trastuzumab or lapatinib and trastuzumab (either concomitantly or sequentially) with or without chemotherapy.

Results:

Median overall survival (OS) in patients receiving trastuzumab after diagnosis of BM was 13 months; corresponding numbers were 9 months in patients treated with chemotherapy, and 3 months with radiotherapy alone. Median OS was not reached in the lapatinib group. Addition of lapatinib prolonged OS over trastuzumab alone (P=0.002). After correction for potential confounders, lapatinib therapy remained an independent positive predictor for survival (HR 0.279; P=0.012).

Interpretation:

This retrospective single-centre study suggests that the introduction of lapatinib improved survival in patients with BM from HER2-positive breast cancer. Patients with KPS ⩾70 may benefit when treated with lapatinib in addition to trastuzumab after completion of local therapy.

Clinical outcome of central nervous system metastases from breast cancer: differences in survival depending on systemic treatment

Central nerve system (CNS) metastases are a feared complication of breast cancer and are associated with poor prognosis. The purpose of this study is to investigate the clinical characteristics of CNS metastases and to clarify the prognostic factors after CNS metastases in breast cancer at a single institution over a long time period. We retrospectively reviewed the medical records of breast cancer patients diagnosed at Seoul National University Hospital from 1981 to 2009 and identified the patients who experienced CNS metastases. We collected the data, including demographics, clinico-pathologic characteristics, dates of diagnosis of original breast cancer and subsequent metastases, and date of death, and correlated the findings with the clinical outcome. A total of 400 patients were identified, of whom 17 (4.3%) were diagnosed with CNS metastases and primary breast cancer concurrently and 383 (95.7%) experienced CNS metastases subsequent to the diagnosis of primary breast cancer. Further, 318 patients (79.5%) had only brain parenchymal metastases, 30 (7.5%) had only leptomeningeal metastases, and 52 (13%) had both. After the diagnosis of CNS metastasis, 170 patients (42.5%) received systemic chemotherapy (CTx) and 143 (35.8%) received CTx after whole brain radiation therapy (WBRT). The patients with good performance status (PS), initial CNS metastasis as recurrence, absence of extracranial metastases, non-visceral extracranial metastases, longer interval from the date of primary breast cancer to the date of CNS metastasis, and CTx after WBRT and gamma-knife surgery (GKS), had better outcomes in univariate analyses. In multivariate analysis, good PS, systemic CTx after WBRT, GKS, and longer interval to CNS metastasis, were independent prognostic factors for overall survival after CNS metastases. Our results suggest that appropriate palliative systemic therapy after WBRT or GKS, and adequate palliative treatment via combined modalities are helpful for breast cancer patients, even after the detection of CNS metastases.

Notch1 inhibition alters the CD44hi/CD24lo population and reduces the formation of brain metastases from breast cancer

Brain metastasis from breast cancer is an increasingly important clinical problem. Here we assessed the role of CD44(hi)/CD24(lo) cells and pathways that regulate them, in an experimental model of brain metastasis. Notch signaling (mediated by γ-secretase) has been shown to contribute to maintenance of the cancer stem cell (CSC) phenotype. Cells sorted for a reduced stem-like phenotype had a reduced ability to form brain metastases compared with unsorted or CD44(hi)/CD24(lo) cells (P < 0.05; Kruskal-Wallis). To assess the effect of γ-secretase inhibition, cells were cultured with DAPT and the CD44/CD24 phenotypes quantified. 231-BR cells with a CD44(hi)/CD24(lo) phenotype was reduced by about 15% in cells treated with DAPT compared with DMSO-treated or untreated cells (P = 0.001, ANOVA). In vivo, mice treated with DAPT developed significantly fewer micro- and macrometastases compared with vehicle treated or untreated mice (P = 0.011, Kruskal-Wallis). Notch1 knockdown reduced the expression of CD44(hi)/CD24(lo) phenotype by about 20%. In vitro, Notch1 shRNA resulted in a reduction in cellular growth at 24, 48, and 72 hours time points (P = 0.033, P = 0.002, and P = 0.009, ANOVA) and about 60% reduction in Matrigel invasion was observed (P < 0.001, ANOVA). Cells transfected with shNotch1 formed significantly fewer macrometastases and micrometastases compared with scrambled shRNA or untransfected cells (P < 0.001; Kruskal-Wallis). These data suggest that the CSC phenotype contributes to the development of brain metastases from breast cancer, and this may arise in part from increased Notch activity.

Management of patients with brain metastases receiving trastuzumab treatment for metastatic breast cancer

BACKGROUND

With the more effective control of visceral metastases in patients with metastatic breast cancer (MBC), an increasing number of patients face brain metastases (BM). The aim of this retrospective analysis was to investigate the incidence and factors affecting the prognosis of patients with BM under trastuzumab treatment for MBC.

PATIENTS AND METHODS

A total of 75 HER2positive patients treated with trastuzumab for MBC were included. RESULTS are discussed in the context of the current literature.

RESULTS

Patients who developed BM (n = 29) had longer median progression-free survival (PFS) during first-line chemotherapy and longer overall survival (OS) after diagnosis of MBC than 46 patients without BM (PFS: 27 vs. 14 months, p = 0.039; OS: 46 vs. 18 months, p = 0.067). Median survival of patients with continuation of trastuzumab after diagnosis of BM was longer than survival of patients with discontinuation of trastuzumab treatment after BM (18 vs. 3 months, p = 0.006). Survival of patients who were treated with surgery and radiotherapy for BM was better compared with radiotherapy alone (9 vs. 5 months, p = not significant) or best supportive care (9 vs. 2 months, p = 0.049).

CONCLUSIONS

Continuation of trastuzumab treatment as well as resection of BM seem to give further benefit in the treatment of patients with HER2-overexpressing MBC.

Multifactorial central nervous system recurrence susceptibility in patients with HER2-positive breast cancer: epidemiological and clinical data from a population-based cancer registry study

BACKGROUND

A series of retrospective studies have reported that patients with human epidermal growth factor receptor 2(HER2)-positive breast cancer are at a greater risk of central nervous system (CNS) metastases. Trastuzumab, which does not cross the blood-brain barrier, has been associated with this increased risk.

METHODS

The authors evaluated incidence, survival, and risk factors for CNS metastases in the incident breast cancer population systematically collected by the Parma Province Cancer Registry over the 4-year period between 2004 and 2007.

RESULTS

A total of 1458 patients with a diagnosis of stage I to III invasive breast cancer were analyzed for study purposes. At a median follow-up of 4.1 years, CNS events were observed in 1.3% and 5% of HER2-negative patients and HER2-positive patients, respectively (P < .0001). The administration of trastuzumab either as adjuvant therapy or for metastatic disease was associated with a significantly increased risk of CNS involvement at first disease recurrence and after first extracranial recurrence, respectively. According to multivariate analysis, HER2-positive status and trastuzumab treatment, high Ki-67 index, and hormone receptor negativity remained independent risk factors for the development of CNS metastasis.

CONCLUSIONS

To the authors' knowledge, this is the first population-based cancer registry study analyzing factors associated with CNS recurrence in a general population of newly diagnosed breast cancer patients with known HER2 status. The data from the current study provide evidence that patients with HER2-positive breast cancer have a significantly higher incidence of CNS metastasis after treatment with trastuzumab. Improvements in systemic control and overall survival associated with trastuzumab-based therapy may lead to an "unmasking" of CNS disease recurrence that would otherwise remain clinically silent before a patient's death.

Radiation therapy for brain metastases in breast cancer patients

Most randomized comparison trials (RCTs) investigating treatments for brain metastases (BM) have included BM from any origin; as a result, more than half (52.4-77.0%) of the BM in these trials originated from the lungs (mostly non-small-cell lung cancer, NSCLC), with the breasts being the origin in only 6.8-19.0% of cases. In addition, patients with poor systemic status (KPS < 70) were not included in these trials. Hence, before we can apply RCT-based information to the daily clinical treatment of BM from breast cancers, it will be crucial to differentiate the characteristics of BM originating from NSCLC and BM originating from breast cancer. Although stereotactic radiosurgery (SRS) is widely used in Japan, level-1 evidence suggests that the benefit of using SRS in addition to whole-brain radiation therapy (WBRT) has been proven only for patients with a single BM. Treatment with SRS alone, which is widely used in Japan, seems attractive because it could avoid the risk of long-term adverse effects of WBRT. However, level-1 evidence suggests that the omission of WBRT results in a high frequency of brain tumor recurrence (BTR). In an RCT between SRS-alone and SRS + WBRT conducted in Japan, we found that patients who had a single BM and no extracranial metastases had a low risk of developing BTR after initial brain management (low-risk group) compared with those who had 2 or more BM and extracranial metastases (high-risk group). In order to meet the criteria of "low-risk" BTR, patients also should have good systemic status (KPS ≧ 70). Epidemiologic data suggest that the prognosis is twice as likely to be poor in patients with BM from breast cancer (RPA III = KPS < 70) than in patients with BM from NSCLC (40 vs. 20%); in addition, the probability of brain-only metastases in patients with breast cancer is less than half that in patients with NSCLC (20-25 vs. 60-75%). Considering these findings, we should be aware that most patients with BM from breast cancer are not good candidates for SRS alone, and, therefore, the role of WBRT is still important in the era of modern radiation techniques.

[Management of metastatic HER2-positive breast cancer: present and future]

HER2-positive breast cancer accounts for 20 to 25% of breast cancers. The surexpression of this tyrosine-kinase receptor is often associated with a poor prognosis. However, the management and the outcome of these patients have changed these last ten years with trastuzumab. Despite the encouraging results obtained with this humanized monoclonal antibody directed against the HER2-receptor, used alone or in association with chemotherapy in metastatic patients, progression under trastuzumab are usually observed and resistances to this treatment are described. Thus, many other monoclonal antibodies and tyrosine-kinase inhibitors emerged. These therapeutics, used alone or in association with chemotherapy or trastuzumab have variable properties: anti-HER2 and anti-EGFR such as lapatinib, pertuzumab and neratinib; anti-EGFR such as erlotinib and gefitinib; antiangiogenesis (bevacizumab, pazopanib); anti-mTOR pathway (temsirolimus, everolimus) or inhibitor of HSP90 (tanespimycine). In this paper, we present an overview on validated targeted therapies and those which are currently under investigation and seem promising in first line or after progression under trastuzumab. Data regarding cardiotoxicity and the use of trastuzumab under particular clinical circumstances (brain metastases, pregnancy) are also reviewed.

Nomogram to predict subsequent brain metastasis in patients with metastatic breast cancer

PURPOSE Brain metastasis is usually a fatal event in patients with stage IV breast cancer. We hypothesized that its occurrence can be predicted if a clinical nomogram can be developed, thus allowing for selection of enriched patient populations for prevention trials. PATIENTS AND METHODS Electronic medical records of patients with metastatic breast cancer were retrospectively reviewed for the period between January 2000 and February 2007 under a study approved by the institutional review board. A multivariate logistic regression analysis of selected prognostic features was done. A nomogram to predict brain metastasis was constructed and validated in a cohort of 128 patients with brain metastasis treated at the Cross Cancer Institute (Edmonton, Alberta, Canada). Results Of 2,136 patients with breast cancer, 362 developed subsequent brain metastasis. Age, grade, negative status of estrogen receptor and human epidermal growth factor receptor 2, number of metastatic sites (one v > one), and short disease-free survival were significantly and independently associated with subsequent brain metastasis. The nomogram showed an area under the receiver operating characteristic curve (AUC) of 0.68 (95% CI, 0.66 to 0.69) in the training set. The validation set showed a good discrimination with an AUC of 0.74 (95% CI, 0.70 to 0.79). The nomogram was well calibrated, with no significant difference between the predicted and the observed probabilities. CONCLUSION We have developed a robust tool that is able to predict subsequent brain metastasis in patients with breast cancer with nonbrain metastatic disease. Selection of an enriched patient population at high risk for brain metastasis will facilitate the design of trials aiming at its prevention.

The role of intra-cerebrospinal fluid treatment and prophylaxis in patients with solid tumors

Metastasis to the central nervous system (CNS), including neoplastic meningitis (NM), is a devastating complication of systemic cancer. With the improved survival of cancer patients, the incidence of CNS metastasis is rising, especially among those with breast or lung carcinoma. New therapies that effectively treat these primary tumors outside of the CNS have underscored the significance of CNS metastases; they have become a significant clinical issue and a therapeutic challenge. This review discusses clinical situations in which treatment or chemoprophylaxis of CNS metastases and NM from breast or lung cancer may play an important role. Potential clinical trials to assess these assumptions also will be proposed.

Human epidermal growth factor receptor 2-positive breast cancer and central nervous system metastases

PURPOSE

To determine the incidence, outcomes, and current strategies for management of brain metastases in patients with human epidermal growth factor receptor 2 (HER2)-positive breast cancer.

METHODS

A literature review was performed to obtain data on central nervous system metastases in patients with breast cancer.

RESULTS

HER2 amplification/overexpression is a prognostic and predictive factor for the development of CNS metastases. Autopsy data show that the incidence rate for CNS metastases in patients with breast cancer is approximately 30%; this may be higher (ie, 30% to 50%) in patients with HER2-positive disease. Treatment with trastuzumab is not associated with an increased incidence of CNS metastases. Data from three phase III adjuvant trials showed the incidence was similar between patients who received trastuzumab and those who did not. Furthermore, trastuzumab can significantly improve overall survival in HER2-positive patients who already have CNS metastases compared with patients who do not receive trastuzumab or those who have HER2-negative brain metastases. This survival advantage is conferred via systemic control of the disease. The current standard of care for patients with CNS metastases is whole-brain radiotherapy (WBRT), with or without surgery, or stereotactic radiosurgery. In the future, novel therapies or combinations of therapies may additionally improve survival in these patients.

CONCLUSION

The incidence of CNS metastases in trastuzumab-treated patients is similar to that in all patients with HER2-positive disease. Trastuzumab can improve survival in patients with HER2-positive disease with CNS metastases.

Trastuzumab treatment in patients with breast cancer and metastatic CNS disease

BACKGROUND

Patients with metastatic central nervous system (mCNS) disease progression from breast cancer have a poor prognosis and often develop associated neurological complications. Human epidermal growth factor receptor 2 (HER2)-positivity status increases the risk of developing mCNS disease. Trastuzumab is an mAb that targets HER2 and is known to extend survival across all stages of HER2-positive breast cancer.

DESIGN

This review considers evidence from preclinical and clinical studies examining the value of continuing trastuzumab treatment in patients who develop mCNS disease. A wealth of data from clinical studies showed that trastuzumab prolonged survival in patients with mCNS disease, compared with no trastuzumab treatment, by effectively controlling their non-CNS disease. Trastuzumab has also been shown to penetrate an impaired blood-brain barrier to a limited degree, such as during radiotherapy, and intrathecal delivery of trastuzumab to the central nervous system (CNS) has shown promise. Research efforts are focussing on improving the delivery of trastuzumab to the CNS.

CONCLUSION

Evidence indicates that patients with mCNS disease from HER2-positive breast cancer should continue to receive trastuzumab to control HER2-positive metastases outside the CNS and receive established therapies to control the mCNS disease.

Role of KCNMA1 gene in breast cancer invasion and metastasis to brain

BACKGROUND

The prognosis for patients with breast tumor metastases to brain is extremely poor. Identification of prognostic molecular markers of the metastatic process is critical for designing therapeutic modalities for reducing the occurrence of metastasis. Although ubiquitously present in most human organs, large-conductance calcium- and voltage-activated potassium channel (BKCa) channels are significantly upregulated in breast cancer cells. In this study we investigated the role of KCNMA1 gene that encodes for the pore-forming alpha-subunit of BKCa channels in breast cancer metastasis and invasion.

METHODS

We performed Global exon array to study the expression of KCNMA1 in metastatic breast cancer to brain, compared its expression in primary breast cancer and breast cancers metastatic to other organs, and validated the findings by RT-PCR. Immunohistochemistry was performed to study the expression and localization of BKCa channel protein in primary and metastatic breast cancer tissues and breast cancer cell lines. We performed matrigel invasion, transendothelial migration and membrane potential assays in established lines of normal breast cells (MCF-10A), non-metastatic breast cancer (MCF-7), non-brain metastatic breast cancer cells (MDA-MB-231), and brain-specific metastatic breast cancer cells (MDA-MB-361) to study whether BKCa channel inhibition attenuates breast tumor invasion and metastasis using KCNMA1 knockdown with siRNA and biochemical inhibition with Iberiotoxin (IBTX).

RESULTS

The Global exon array and RT-PCR showed higher KCNMA1 expression in metastatic breast cancer in brain compared to metastatic breast cancers in other organs. Our results clearly show that metastatic breast cancer cells exhibit increased BKCa channel activity, leading to greater invasiveness and transendothelial migration, both of which could be attenuated by blocking KCNMA1.

CONCLUSION

Determining the relative abundance of BKCa channel expression in breast cancer metastatic to brain and the mechanism of its action in brain metastasis will provide a unique opportunity to identify and differentiate between low grade breast tumors that are at high risk for metastasis from those at low risk for metastasis. This distinction would in turn allow for the appropriate and efficient application of effective treatments while sparing patients with low risk for metastasis from the toxic side effects of chemotherapy.

Contemporary issues and the potential uses of capecitabine in metastatic breast cancer

Since its first regulatory approval more than 10 years ago, oncologists have gained wide experience in using the oral fluoropyrimidine, capecitabine, as monotherapy or in combination with other agents and the body of evidence supporting these approaches continues to grow. Alongside this increasing experience has been the appearance of new challenges in patient management. We now recognise several different biological subtypes of breast cancer, such as HER2-positive disease. The standard of care in these tumours comprises anti-HER2 therapy, and phase III data show that capecitabine can be effectively combined with such agents. Another increasingly prominent and currently unresolved issue resulting from more effective treatment of metastatic disease is the management of patients with brain metastases. The introduction of new, well-tolerated, oral chemotherapies also provides the opportunity for longer duration of therapy. These new clinical scenarios are discussed in the current review.

Risk factors for brain relapse in HER2-positive metastatic breast cancer patients

Brain relapse is a common occurrence in HER2-positive breast cancer patients. However, the factors determining the risk of brain metastasis in these patients remain to be established. The aim of this study was to assess the impact of particular clinical and pathological factors on the risk of brain relapse in HER2-positive advanced breast cancer patients. The study group included 264 consecutive HER-2 positive metastatic breast cancer patients, most of whom (210; 80%) were administered trastuzumab, usually in combination with chemotherapy. Time from the diagnosis to distant relapse ranged from 0 to 142 months (median 16 months). The most common dominant site of metastatic disease was viscera (80%), followed by soft tissue (11%) and bones (10%). After a median follow-up of 3.1 years, the symptomatic brain relapse occurred in 103 patients (39%). Median time from treatment dissemination to brain relapse was 15 months (range, 0-81 months), and the cumulative 1-year, 3-year and 5-year risk of brain relapse was 17, 42 and 55%, respectively. The average annual risk of brain relapse for surviving patients during consecutive 7 years of follow-up was 10.0% (95% CI, 6.6-13.5%). In the univariate analysis the only variable significantly related to the increased risk of brain relapse was time from initial diagnosis to distant relapse shorter than 2 years (HR = 1.55, 95% CI, 1.03-2.33, P = 0.034). Patients with dominant site of disease in soft tissue or bones tended to have lower risk of relapse (HR = 0.54 and 0.62; P = 0.098 and 0.203, respectively) compared to patients with visceral metastases. Treatment with trastuzumab was not associated with reduced risk of brain relapse (HR = 0.91, 95% CI, 0.47-1.77, P = 0.78). In the multivariate analysis, time from initial diagnosis to distant relapse shorter than 2 years remained the only significant variable related to increased risk of brain relapse (adjusted HR = 1.62, 95% CI, 1.07-2.44; P = 0.022). HER2-positive breast cancer patients remain at high and continuous risk of brain relapse for a prolonged period of time after diagnosis of disease dissemination. Short time from initial diagnosis to distant relapse is related to increased risk of brain relapse. Molecular predictors are sorely needed to better characterize patients with high probability of early brain relapse.