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.     

Challenges in the treatment of hormone receptor-positive,HER2-negative metastatic breast cancer with brain metastases

Brain metastases are a major cause of morbidity and mortality for women with hormone receptor (HR)-positive breast cancer, yet little is known about the optimal treatment of brain disease in this group of patients. Although these patients are at lower risk for brain metastases relative to those with HER2-positive and triple-negative disease, they comprise the majority of women diagnosed with breast cancer. Surgery and radiation continue to have a role in the treatment of brain metastases, but there is a dearth of effective systemic therapies due to the poor penetrability of many systemic drugs across the blood-brain barrier (BBB). Additionally, patients with brain metastases have long been excluded from clinical trials, and few studies have been conducted to evaluate the safety and effectiveness of systemic therapies specifically for the treatment of HER2-negative breast cancer brain metastases. New approaches are on the horizon, such as nanoparticle-based cytotoxic drugs that have the potential to cross the BBB and provide clinically meaningful benefits to patients with this life-threatening consequence of HR-positive breast cancer.     

Brain metastases: the HER2 paradigm.

Between 100,000 and 170,000 patients with cancer develop central nervous system (CNS) metastases each year in the U.S., of which approximately 20% carry a primary diagnosis of breast cancer. As a consequence of improvements in systemic therapy, which have allowed patients to live longer with advanced cancer, CNS metastases are emerging as an important sanctuary site, and the incidence may be increasing in patients with particular tumor subtypes. Unless there are improvements in the treatment of CNS disease, a growing proportion of patients may be at risk of experiencing both morbidity and mortality as a result of uncontrolled CNS progression, often at a time when their extra-CNS disease is apparently under control. This article reviews changes in the epidemiology and natural history of women with brain metastases from HER2-positive breast cancer over the last decade and presents the therapeutic challenges and opportunities that have arisen in this setting. First, the apparent increase in CNS disease among women with HER2-positive breast cancer, relative to historical controls, is discussed, followed by consideration of potential causes of this observation. Next, the implications of CNS disease, in terms of prognosis and the potential development of preventive strategies are considered. Finally, new developments in systemic approaches to the treatment of CNS disease, including cytotoxic chemotherapy and targeted therapy, are explored.     

Evolving management of HER2+ breast cancer brain metastases and leptomeningeal disease

Journal of Neuro-Oncology - Patients with human epidermal growth factor receptor 2 (HER2)-positive breast cancer are at a particularly high risk of breast cancer brain metastasis (BCBM) and...     

EGFR, HER2 and HER3 expression in esophageal primary tumours and corresponding metastases

The expression of EGFR, HER2 and HER3 receptors were analyzed in immunohistochemical preparations from primary esophageal tumours and corresponding lymph node metastases. The goal was to evaluate whether any of these receptors are suitable as targets for radionuclide based imaging and therapy. The receptor expressions were evaluated in parallel samples, primary tumour and metastasis, from each patient (n=51). The majority of the cases were esophageal squamous cell carcinomas, ESCC (n=40). The HercepTest scoring was used for the analysis of both HER2 and EGFR expression (0, 1+, 2+ or 3+). HER3 was only evaluated as negative, weak or strong staining. EGFR overexpression (2+/3+) was found in 67.5% (27/40) of both the ESCC primary tumours and the corresponding lymph node metastases. There were only a few changes in these EGFR-scores: two cases from 2+/3+ to 0/1+ when the primary tumours were compared to the corresponding metastases and 2 changes the other way around. HER2 overexpression (2+/3+) was found in only 3 of the primary ESCC tumours and 2 of the lymph node metastases. EGFR and HER2 stainings were found mainly in the cell membranes. The HER3 staining (weak or strong) was mainly cytoplasmic and granular and was observed in about half (20/39) of the cases, for both the ESCC primary tumours and the corresponding lymph node metastases. It was concluded that ESCC lymph node metastases generally have a strong expression of EGFR in their cell membranes and to the same extent as in the primary tumours. The stability in EGFR expression is encouraging for efforts to develop radionuclide based EGFR imaging agents. It is also possible that EGFR targeting agents (e.g. Iressa, Tarceva, Erbitux or radiolabelled antibodies) can be applied for therapy of ESCC.     

A systematic review of trastuzumab and lapatinib in the treatment of women with brain metastases from HER2-positive breast cancer

Patients with HER2-positive breast cancer are living still longer and increasingly experiencing brain metastases. Current HER2-targeted therapies have limited potential to cross the blood–brain-barrier. We performed a systematic review to investigate data on HER2-targeting therapies in the treatment of brain metastases in breast cancer. We searched PUBMED for all human studies published 1998–2012 using the following search terms: breast neoplasm/cancer, human epidermal growth factor receptor 2/HER2, ErbB2, trastuzumab, lapatinib, brain/cerebral neoplasm/metastases and blood–brain barrier. We identified few and mostly small clinical studies. Study designs were very heterogeneous making comparisons on endpoints difficult. Overall survival for patients treated with trastuzumab varied from 8 to 25 months and 5.5 to 11 months for patients receiving lapatinib. The majority of studies were retrospective thus possibly biasing data. Only three studies were identified comparing trastuzumab to lapatinib. Conclusively, no solid data exist on how to treat patients with HER2-positive disease and brain metastases. Although continuous HER2-blockade is recommended by international consensus guidelines, it is still not evident which HER2-targeting agent should be preferred when brain metastases occur. The choice of chemotherapy to accompany the blockade is not obvious and we do not know if dual is better than single blockade. Further clinical trials are urgently needed.     

Presentation,patterns of care,and survival in patients with brain metastases

BACKGROUND:

It is largely unknown to what extent new oncologic treatment options have improved survival of patients with brain metastasis in recent decades. Therefore, a multi‐institutional time‐staggered analysis was performed.

METHODS:

Two cohorts of 103 patients each were analyzed, one treated between 2005 and 2009 and the other between 1983 and 1989, ie, approximately 20 years earlier. Stratified analyses by prognostic groups were also performed (graded prognostic assessment [GPA] and Radiation Therapy Oncology Group recursive partitioning analysis [RTOG‐RPA]).

RESULTS:

Patterns of care have changed significantly. Contemporary patients received focal treatments such as stereotactic radiosurgery and surgical resection far more frequently. Furthermore, systemic treatment was used more often in contemporary patients, both before and after diagnosis of brain metastasis. Improved survival was observed in the contemporary cohort (P = .03). The 1‐year survival rate increased from 15% (95% confidence interval [CI], 7%‐25%) to 34% (95% CI, 25%‐44%). However, this improvement was largely driven by patients with favorable prognostic features. More than 40% of the patients still belong to unfavorable prognostic groups with limited median survival and little improvement.

CONCLUSIONS:

Contemporary patients were managed on a much more individualized basis, requiring multidisciplinary case discussion and thorough assessment of prognostic features. Progress has been made, but the overall outcome needs to be improved further. Avoiding overtreatment in patients with poor prognosis is as important as aggressive treatment in patients who might survive for several years. Cancer 2011. © 2010 American Cancer Society.     

Excision of solitary brain metastases: Effect on survival

Retrospective analysis of 88 patients treated for brain metastases at Veterans Administration and Erie County Medical Centers, Buffalo, New York, between January 1975 and August 1980 is presented. Patients were followed until January 1981. They were classified into three groups: Group I—15 patients with solitary brain metastases treated by surgical excision followed by radiotherapy (SBM-S). Group II—32 patients with solitary brain metastases treated by radiotherapy alone (SBM-RT). Group III—41 patients with multiple brain metastases treated by radiotherapy (MBM-RT). The average survival was 216 days for the first group versus 80 and 106 days for the second and third groups, respectively. Three patients in the first group were still living at five, eighteen, and twenty-one months versus one patient each in the second and third group at five months. When brain metastases appeared either at time of presentation or within two months from the diagnosis of the primary disease, excision of solitary brain metastases did not prolong survival. Survival periods were 114, 53, and 81 days for Group I, II, and III, respectively. When brain metastasis appeared after a minimum of two months from the treatment of the primary lesion, excision of solitary brain metastasis did prolong patient survivals for 286 days versus 128 and 94 days for Groups I, II, and III, respectively. When the primary site of origin was inoperable lung cancer or unknown primary cancer no difference in survival between the three groups, survival was 80, 50, and 70 days for Groups I, II, and III, respectively. Percentage survival at 2, 6, and 12 months was 67%, 53%, and 27% in the first group versus 32%, 16%, and 3% for the second group and 41%, 15%, and 5% for the third group. We conclude that excision of solitary brain metastasis might prolong survival in selected patients.     

PI3K pathway inhibitors for the treatment of brain metastases with a focus on HER2+ breast cancer

The incidence of breast cancer brain metastases has increased in recent years, largely due to improved control of systemic disease with human epidermal growth factor receptor 2 (HER2)-targeted agents and the inability of most of these agents to efficiently cross the blood–blood barrier (BBB) and control central nervous system disease. There is, therefore, an urgent unmet need for treatments to prevent and treat HER2+ breast cancer brain metastases (BCBMs). Aberrant activation of the phosphatidylinositol 3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) signaling pathway is frequently observed in many cancers, including primary breast tumors and BCBMs. Agents targeting key components of this pathway have demonstrated antitumor activity in diverse cancers, and may represent a new treatment strategy for BCBMs. In preclinical studies, several inhibitors of PI3K and mTOR have demonstrated an ability to penetrate the BBB and down-regulate PI3K signaling, indicating that these agents may be potential therapies for brain metastatic disease. The PI3K inhibitor buparlisib (BKM120) and the mTOR inhibitor everolimus (RAD001) are currently under evaluation in combination with trastuzumab in patients with HER2+ BCBMs.     

Metastatic melanoma: prognostic factors and survival in patients with brain metastases

There is no standard therapy for recurrent anaplastic glioma (AG). Salvage therapies include alkylator-based chemotherapy, re-resection with or without carmustine implants, re-irradiation and bevacizumab. Bendamustine is a novel bifunctional alkylator with CNS penetration never previously evaluated in AG. Assess response and toxicity of bendamustine in recurrent AG in a phase II trial. Adults with radiation and temozolomide refractory recurrent AG were treated with bendamustine. A cycle of bendamustine was defined as two consecutive days of treatment (100 mg/m²/day) administered once every 4 weeks. Success of treatment was defined as progression free survival (PFS) at 6 months of 40?% or better. Twenty-six adults [16 males; 10 females: median age 40 years (range 30–65)] were treated, 12 at first recurrence and 17 at second recurrence. Prior salvage therapy included re-resection (14), chemotherapy (11) and re-radiation (2). Grade 3 treatment-related toxicities included lymphopenia (11 patients; Grade 4 in 3), myalgia, pneumonia, diarrhea, leukopenia, allergic reaction and thrombocytopenia in one patient each. One patient discontinued therapy due to toxicity. There were five instances of bendamustine dose delays all due to lymphopenia. There were no dose reductions due to toxicity. The median number of cycles of therapy was 3 (range 1–8). Best radiographic response was progressive disease in 12 (46?%), stable disease in 13 (50?%) and partial response in 1 (4?%). Median, 6- and 12-month PFS was 2.7 months (range 1–52), 27 and 8?% respectively. In patients with recurrent AG refractory to Z, bendamustine has manageable toxicity and modest single agent activity though not meeting pre-specified study criteria.     

Expression of HER2/erbB-2 correlates with survival in osteosarcoma.

PURPOSE: In osteosarcoma, prognostic factors at diagnosis other than clinical stage have not been clearly identified. The aim of this study was to determine whether human epidermal growth factor receptor 2 (HER2)/erbB-2, p-glycoprotein, or p53 expression correlated with histologic response to preoperative chemotherapy or event-free survival. PATIENTS AND METHODS: We performed a retrospective immunohistochemical study on material obtained from patients treated on the Memorial Sloan-Kettering Cancer Center T12 protocol between 1986 and 1993. Paraffin-embedded tissue was identified from 53 patients (73% of patients enrolled onto protocol) and stained for HER2/erbB-2, p53, and p-glycoprotein expression using standard monoclonal antibodies and methods. RESULTS: At the time of initial biopsy, 20 (42.6%) of 47 samples demonstrated high levels of HER2/erbB-2 expression. Higher frequencies of expression were observed in samples from patients with metastatic disease at presentation and at the time of relapse. Expression of HER2/erbB-2 correlated with a significantly worse histologic response (P =.03). In patients presenting with nonmetastatic disease, expression of HER2/erbB-2 at the time of initial biopsy was associated with a significantly decreased event-free survival (47% v 79% at 5 years, P =.05). p53 and p-glycoprotein expression did not correlate with histologic response or patient event-free survival. CONCLUSION: The correlation of HER2/erbB-2 expression with histologic response to preoperative chemotherapy and event-free survival in this study suggests that HER2/erbB-2 should be evaluated prospectively as a prognostic indicator. The correlation also suggests that clinical trials of antibodies that target this receptor, such as recombinant humanized anti-HER2 monoclonal antibody (Herceptin; Genentech, San Francisco, CA), should be considered for the treatment of osteosarcoma.