The HERBA Study: A Retrospective Multi-Institutional Italian Study on Patients With Brain Metastases From HER2-Positive Breast Cancer

Surgery for brain metastases: radiooncology scores predict survival-score index for radiosurgery, graded prognostic assessment, recursive partitioning analysis

BACKGROUND

Radiooncological scores are used to stratify patients for radiation therapy. We assessed their ability to predict overall survival (OS) in patients undergoing surgery for metastatic brain disease.

METHODS

We performed a post-hoc single-center analysis of 175 patients, prospectively enrolled in the MetastaSys study data. Score index of radiosurgery (SIR), graded prognostic assessment (GPA), and recursive partitioning analysis (RPA) were assessed. All scores consider age, systemic disease, and performance status prior to surgery. Furthermore, GPA and SIR include the number of intracranial lesions while SIR additionally requires metastatic lesion volume. Predictive values for case fatality at 1 year after surgery were compared among scoring systems.

RESULTS

All scores produced accurate reflections on OS after surgery (p ≤ 0.003). Median survival was 21-24 weeks in patients scored in the unfavorable cohorts, respectively. In cohorts with favorable scores, median survival ranged from 42 to 60 weeks. Favorable SIR was associated with a hazard ratio (HR) of 0.44 [0.29, 0.66] for death within 1 year. For GPA, the HR amounted to 0.44 [0.25, 0.75], while RPA had a HR of 0.30 [0.14, 0.63]. Overall test performance was highest for the SIR.

CONCLUSIONS

All scores proved useful in predicting OS. Considering our data, we recommend using the SIR for preoperative prognostic evaluation and counseling.

Characteristics of patients with brain metastases from human epidermal growth factor receptor 2-positive breast cancer: subanalysis of Brain Metastases in Breast Cancer Registry

Background

Up to 40% of patients with metastatic human epidermal growth factor receptor 2 (HER2)-positive breast cancer develop brain metastases (BMs). Understanding of clinical features of these patients with HER2-positive breast cancer and BMs is vital.

Patients and methods

A total of 2948 patients from the Brain Metastases in Breast Cancer registry were available for this analysis, of whom 1311 had primary tumors with the HER2-positive subtype.

Results

Patients with HER2-positive breast cancer and BMs were—when compared with HER2-negative patients—slightly younger at the time of breast cancer and BM diagnosis, had a higher pathologic complete response rate after neoadjuvant chemotherapy and a higher tumor grade. Furthermore, extracranial metastases at the time of BM diagnosis were less common in HER2-positive patients, when compared with HER2-negative patients. HER2-positive patients had more often BMs in the posterior fossa, but less commonly leptomeningeal metastases. The median overall survival (OS) in all HER2-positive patients was 13.2 months (95% confidence interval 11.4-14.4). The following factors were associated with shorter OS (multivariate analysis): older age at BM diagnosis [≥60 versus <60 years: hazard ratio (HR) 1.63, P < 0.001], lower Eastern Cooperative Oncology Group status (2-4 versus 0-1: HR 1.59, P < 0.001), higher number of BMs (2-3 versus 1: HR 1.30, P = 0.082; ≥4 versus 1: HR 1.51, P = 0.004; global P = 0.015), BMs in the fossa anterior (HR 1.71, P < 0.001), leptomeningeal metastases (HR 1.63, P = 0.012), symptomatic BMs at diagnosis (HR 1.35, P = 0.033) and extracranial metastases at diagnosis of BMs (HR 1.43, P = 0.020). The application of targeted therapy after the BM diagnosis (HR 0.62, P < 0.001) was associated with longer OS. HER2-positive/hormone receptor-positive patients showed longer OS than HER2-positive/hormone receptor-negative patients (median 14.3 versus 10.9 months; HR 0.86, P = 0.03), but no differences in progression-free survival were seen between both groups.

Conclusions

We identified factors associated with the prognosis of HER2-positive patients with BMs. Further research is needed to understand the factors determining the longer survival of HER2-positive/hormone receptor-positive patients.

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Patients with HER2-positive BMs from breast cancer have the best prognosis compared with other tumor subtypes.

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Among HER2-positive patients, hormone receptor-positive patients have the longest survival.

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HER2-targeted therapy is significantly associated with a better prognosis in patients with BMs.

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On average, two HER2-targeted therapy lines were administered prior to the development of BMs.

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New compounds are urgently needed to improve the outcome of this subgroup of patients.

Improving Brain Metastases Outcomes Through Therapeutic Synergy Between Stereotactic Radiosurgery and Targeted Cancer Therapies

Brain metastases are the most common form of brain cancer. Increasing knowledge of primary tumor biology, actionable molecular targets and continued improvements in systemic and radiotherapy regimens have helped improve survival but necessitate multidisciplinary collaboration between neurosurgical, medical and radiation oncologists. In this review, we will discuss the advances of targeted therapies to date and discuss findings of studies investigating the synergy between these therapies and stereotactic radiosurgery for non-small cell lung cancer, breast cancer, melanoma, and renal cell carcinoma brain metastases.

Radiotherapy for HER 2 Positive Brain Metastases: Urgent Need for a Paradigm Shift

Brain metastases (BMs) are common among patients affected by HER2+ metastatic breast cancer (>30%). The management of BMs is usually multimodal, including surgery, radiotherapy, systemic therapy and palliative care. Standard brain radiotherapy (RT) includes the use of stereotactic radiotherapy (SRT) for limited disease and whole brain radiotherapy (WBRT) for extensive disease. The latter is an effective palliative treatment but has a reduced effect on brain local control and BM overall survival, as it is also associated with severe neurocognitive sequelae. Recent advances both in radiation therapy and systemic treatment may change the paradigm in this subset of patients who can experience long survival notwithstanding BMs. In fact, in recent studies, SRT for multiple BM sites (>4) has shown similar efficacy when compared to irradiation of a limited number of lesions (one to three) without increasing toxicity. These findings, in addition to the introduction of new drugs with recognized intracranial activity, may further limit the use of WBRT in favor of SRT, which should be employed for treatment of both multiple-site BMs and for oligo-progressive brain disease. This review summarizes the supporting literature and highlights the need for optimizing combinations of the available treatments in this setting, with a particular focus on radiation therapy.

Breast Cancer Subtypes and Mortality of Breast Cancer Patients With Brain Metastasis at Diagnosis: A Population-Based Study

Background

Brain metastasis is an important cause of breast cancer-related death.

Aim

We evaluated the relationships between breast cancer subtype and prognosis among patients with brain metastasis at the initial diagnosis.

Methods

The Surveillance, Epidemiology, and End Results database was searched to identify patients with brain metastasis from breast cancer between 2010 and 2015. Multivariable Cox proportional hazard models were used to identify factors that were associated with survival among patients with initial brain metastases. The Kaplan–Meier method was used to compare survival outcomes according to breast cancer subtype.

Results

Among 752 breast cancer patients with brain metastasis at diagnosis, 140 patients (18.6%) underwent primary surgery and 612 patients (81.4%) did not undergo surgery, while 460 patients (61.2%) received chemotherapy and 292 patients (38.8%) did not receive chemotherapy. Multivariable analysis revealed that, relative to HR+/HER2– breast cancer, HR–/HER2– breast cancer was associated with significantly poorer overall survival (hazard ratio: 2.52, 95% confidence interval: 1.99–3.21), independent of age, sex, race, marital status, insurance status, grade, liver involvement, lung involvement, primary surgery, radiotherapy, and chemotherapy. The median overall survival intervals were 12 months for HR+/HER2−, 19 months for HR+/HER2+, 11 months for HR−/HER2+, and 6 months for HR–/HER2– (P < .0001). Relative to HR+/HER2– breast cancer, HR–/HER2– breast cancer was associated with a significantly higher risk of mortality among patients, and the association was stronger among patients who received chemotherapy (p for interaction = .005).

Conclusions

Breast cancer subtype significantly predicted overall survival among patients with brain metastasis at diagnosis.

Prognostic factors of brain metastasis and survival among HER2-positive metastatic breast cancer patients: a systematic literature review

BACKGROUND

Patients with breast cancer who overexpress the human epidermal growth factor receptor 2 (HER2) and subsequently develop brain metastasis (BM) typically experience poor quality of life and low survival. We conducted a comprehensive literature review to identify prognostic factors for BM and predictors of survival after developing BM, and the effects of therapies with different mechanisms of action among patients with HER2+ breast cancer (BC).

METHODS

A prespecified search strategy was used to identify research studies investigating BM in patients with HER2+ BC published in English during January 1, 2009-to June 25, 2021. Articles were screened using a two-phase process, and data from selected articles were extracted.

RESULTS

We identified 25 published articles including 4097 patients with HER2+ BC and BM. Prognostic factors associated with shorter time to BM diagnosis after initial BC diagnosis included younger age, hormone receptor negative status, larger tumor size or higher tumor grade, and lack of treatment with anti-HER2 therapy. Factors predictive of longer survival after BM included having fewer brain lesions (< 3 or a single lesion) and receipt of any treatment after BM, including radiosurgery, neurosurgery and/or systemic therapy. Patients receiving combination trastuzumab and lapatinib therapy or trastuzumab and pertuzumab therapy had the longest median survival compared with other therapies assessed in this review.

CONCLUSIONS

More research is needed to better understand risk factors for BM and survival after BM in the context of HER2+ BC, as well as the assessment of new anti-HER2 therapy regimens that may provide additional therapeutic options for BM in these patients.

Current treatment options for HER2-positive breast cancer patients with brain metastases

Brain metastases (BMs) are frequently associated with HER2+ breast cancer (BC). Their management is based on a multi-modal strategy including both local treatment and systemic therapy. Despite therapeutic advance, BMs still have an adverse impact on survival and quality of life and the development of effective systemic therapy to prevent and treat BMs from HER2 + BC represents an unmet clinical need. Trastuzumab-based therapy has long been the mainstay of systemic therapy and over the last two decades other HER2-targeted agents including lapatinib, pertuzumab and trastuzumab emtansine, have been introduced in the clinical practice. More recently, novel agents such as neratinib, tucatinib and trastuzumab deruxtecan have been developed, with interesting activity against BMs. Further research is needed to better elucidate the best sequence of these agents and their combination with local treatment.

Enhanced brain delivery and therapeutic activity of trastuzumab after blood-brain barrier opening by NEO100 in mouse models of brain-metastatic breast cancer

BACKGROUND

The antitumor efficacy of human epidermal growth factor receptor 2 (HER2)-targeted therapies, such as humanized monoclonal antibody trastuzumab (Herceptin®, Roche), in patients with breast-to-brain cancer metastasis is hindered by the low permeability of the blood-brain barrier (BBB). NEO100 is a high-purity version of the natural monoterpene perillyl alcohol, produced under current good manufacturing practice (cGMP) regulations, that was shown previously to reversibly open the BBB in rodent models. Here we investigated whether NEO100 could enable brain entry of trastuzumab to achieve greater therapeutic activity.

METHODS

An in vitro BBB, consisting of human astrocytes and brain endothelial cells, was used to determine trastuzumab penetration in the presence or absence of NEO100. For in vivo studies, we administered intravenous (IV) trastuzumab or the trastuzumab-drug conjugate ado-trastuzumab emtansine (T-DM1; Kadcyla®, Roche), to mouse models harboring intracranial HER2+ breast cancer, with or without BBB opening via IA NEO100. Brain and tumor tissues were examined for the presence of trastuzumab and infiltration of immune cells. Therapeutic impact was evaluated based on overall survival.

RESULTS

NEO100 greatly increased trastuzumab penetration across an in vitro BBB. In vivo, IA NEO100-mediated BBB opening resulted in brain tumor-selective accumulation of trastuzumab, without detectable presence in normal brain tissue, along with increased presence of immune cell populations. IV delivery of trastuzumab or T-DM1 achieved significantly greater overall survival of tumor-bearing mice when combined with IA NEO100.

CONCLUSION

IA NEO100 facilitates brain tumor entry of trastuzumab and T-DM1 and significantly enhances their therapeutic efficacy, along with increased antibody-dependent immune cell recruitment.

Management of brain metastases according to molecular subtypes

The incidence of brain metastases has markedly increased in the past 20 years owing to progress in the treatment of malignant solid tumours, earlier diagnosis by MRI and an ageing population. Although local therapies remain the mainstay of treatment for many patients with brain metastases, a growing number of systemic options are now available and/or are under active investigation. HER2-targeted therapies (lapatinib, neratinib, tucatinib and trastuzumab emtansine), alone or in combination, yield a number of intracranial responses in patients with HER2-positive breast cancer brain metastases. New inhibitors are being investigated in brain metastases from ER-positive or triple-negative breast cancer. Several generations of EGFR and ALK inhibitors have shown activity on brain metastases from EGFR and ALK mutant non-small-cell lung cancer. Immune-checkpoint inhibitors (ICIs) hold promise in patients with non-small-cell lung cancer without druggable mutations and in patients with triple-negative breast cancer. The survival of patients with brain metastases from melanoma has substantially improved after the advent of BRAF inhibitors and ICIs (ipilimumab, nivolumab and pembrolizumab). The combination of targeted agents or ICIs with stereotactic radiosurgery could further improve the response rates and survival but the risk of radiation necrosis should be monitored. Advanced neuroimaging and liquid biopsy will hopefully improve response evaluation.

HER2-targeted therapy prolongs survival in patients with HER2-positive breast cancer and intracranial metastatic disease: a systematic review and meta-analysis

BACKGROUND

Intracranial metastatic disease (IMD) is a serious and known complication of human epidermal growth factor receptor 2 (HER2)-positive breast cancer. The role of targeted therapy for patients with HER2-positive breast cancer and IMD remains unclear. In this study, we sought to evaluate the effect of HER2-targeted therapy on IMD from HER2-positive breast cancer.

METHODS

We searched MEDLINE, EMBASE, CENTRAL, and gray literature sources for interventional and observational studies reporting survival, response, and safety outcomes for patients with IMD receiving HER2-targeted therapy. We pooled outcomes through meta-analysis and examined confounder effects through forest plot stratification and meta-regression. Evidence quality was evaluated using GRADE (PROSPERO CRD42020161209).

RESULTS

A total of 97 studies (37 interventional and 60 observational) were included. HER2-targeted therapy was associated with prolonged overall survival (hazard ratio [HR] 0.47; 95% confidence interval [CI], 0.39-0.56) without significantly prolonged progression-free survival (HR 0.52; 95% CI, 0.27-1.02) versus non-targeted therapy; the intracranial objective response rate was 19% (95% CI, 12-27%), intracranial disease control rate 62% (95% CI, 55-69%), intracranial complete response rate 0% (95% CI, 0-0.01%), and grade 3+ adverse event rate 26% (95% CI, 11-45%). Risk of bias was high in 40% (39/97) of studies.

CONCLUSION

These findings support a potential role for systemic HER2-targeted therapy in the treatment of patients with IMD from HER2-positive metastatic breast cancer.