Because of improvements in the treatment of patients with metastatic breast cancer, the development of brain metastases (BM) has become a major limitation of life expectancy and quality of life for many breast cancer patients. The improvement of management strategies for BM is thus an important clinical challenge, especially among high-risk patients such as human epidermal growth factor receptor 2-positive and triple-negative patients. However, the formation of BM as a multistep process is thus far poorly understood. To grow in the brain, single tumor cells must pass through the tight blood–brain barrier (BBB). The BBB represents an obstacle for circulating tumor cells entering the brain, but it also plays a protective role against immune cell and toxic agents once metastatic cells have colonized the cerebral compartment. Furthermore, animal studies have shown that, after passing the BBB, the tumor cells not only require close contact with endothelial cells but also interact closely with many different brain residential cells. Thus, in addition to a genetic predisposition of the tumor cells, cellular adaptation processes within the new microenvironment may also determine the ability of a tumor cell to metastasize. In this review, we summarize the biology of breast cancer that has spread into the brain and discuss the implications for current and potential future treatment strategies.

Brain metastases (BMs) have a major impact on life expectancy and quality of life for many breast cancer patients. Knowledge about treatment patterns and outcomes is limited. We analysed clinical data of 1712 patients diagnosed with BMs from breast cancer between January 2000 and December 2016 at 80 institutions. Median age at diagnosis of BMs was 56 years (22-90 years). About 47.8% (n = 732) of patients had HER2-positive, 21.4% (n = 328) had triple-negative and 30.8% (n = 471) had hormone receptor (HR)-positive, HER2-negative (luminal-like) primary tumours. The proportion of patients with HER2-positive BMs decreased comparing the years 2000-2009 with 2010-2015 (51%-44%), whereas the percentage of patients with luminal-like tumours increased (28%-34%; p = 0.0331). Patients with BMs in the posterior fossa were more often HER2 positive (n = 169/314, 53.8%) than those diagnosed with triple-negative (n = 65/314, 20.7%) or luminal-like primary breast cancer (n = 80/314, 25.5%), (p < 0.0001). Median overall survival (OS) time after development of BMs for the overall cohort was 7.4 months (95% confidence interval [CI]: 6.7-8.0 months). One-year survival rate was 37.7% (95% CI: 35.2-40.1). Patients with HER2-positive tumours had the longest median OS of 11.6 months (95% CI: 10.0-13.4) compared with 5.9 months (95% CI: 5.0-7.2) for patients with luminal-like and 4.6 months (95% CI: 3.9-5.4) for patients with triple-negative tumours. Patients with HER2-positive tumours who received anti-HER2 treatment had longer median OS than those without (17.1 months versus 7.2 months, p < 0.0001). Prognosis of patients after developing BMs varies significantly according to the subtype. The outcome in this cohort is similarly poor in triple-negative and HR-positive/HER2-negative patients. Our results underline the high medical need for improvement of treatment and prevention strategies for BMs in breast cancer patients.

Introduction: The AGO (Arbeitsgemeinschaft Gynäkologische Onkologie, German Gynecological Oncology Group) Task Force on Diagnosis and Treatment of Breast Cancer as an interdisciplinary team consists of specialists from gynecological oncology, pathology, diagnostic radiology, medical oncology, and radiation oncology with a special focus on breast cancer. Methods: The updated evidence-based treatment recommendation 2022 for early breast cancer (EBC) and metastatic breast cancer of the AGO Task Force has been released. Results and Conclusion: This paper captures the update of EBC.

The incidence of brain metastases in breast cancer (BCBM) patients is increasing. These patients have a very poor prognosis, and therefore, identification of blood-based biomarkers, such as circulating tumor cells (CTCs), and understanding the genomic heterogeneity could help to personalize treatment options. Both EpCAM-dependent (CellSearch® System) and EpCAM-independent Ficoll-based density centrifugation methods were used to detect CTCs from 57 BCBM patients. DNA from individual CTCs and corresponding primary tumors and brain metastases were analyzed by next-generation sequencing (NGS) in order to evaluate copy number aberrations and single nucleotide variations (SNVs). CTCs were detected after EpCAM-dependent enrichment in 47.7% of the patients (≥ 5 CTCs/7.5 ml blood in 20.5%). The CTC count was associated with ERBB2 status (p = 0.029) of the primary tumor as well as with the prevalence of bone metastases (p = 0.021). EpCAM-independent enrichment revealed CTCs in 32.6% of the patients, especially among triple-negative breast cancer (TNBC) patients (70.0%). A positive CTC status after enrichment of either method was significantly associated with decreased overall survival time (p < 0.05). Combining the results of both enrichment methods, 63.6% of the patients were classified as CTC positive. In three patients, the matched tumor tissue and single CTCs were analyzed by NGS showing chromosomal aberrations with a high genomic clonality and mutations in pathways potentially important in brain metastasis formation. The detection of CTCs, regardless of the enrichment method, is of prognostic relevance in BCBM patients and in combination with molecular analysis of CTCs can help defining patients with higher risk of early relapse and suitability for targeted treatment.

Breast cancer (BC) is the most frequent cause of cancer-associated death for women worldwide, with deaths commonly resulting from metastatic spread to distant organs. Approximately 30% of metastatic BC patients develop brain metastases (BM), a currently incurable diagnosis. The influence of BC molecular subtype and gene expression on breast cancer brain metastasis (BCBM) development and patient prognosis is undeniable and is, therefore, an important focus point in the attempt to combat the disease. The HER2-positive and triple-negative molecular subtypes are associated with an increased risk of developing BCBM. Several genetic and molecular mechanisms linked to HER2-positive and triple-negative BC breast cancers appear to influence BCBM formation on several levels, including increased development of circulating tumor cells (CTCs), enhanced epithelial-mesenchymal transition (EMT), and migration of primary BC cells to the brain and/or through superior local invasiveness aided by cancer stem-like cells (CSCs). These specific BC characteristics, together with the ensuing developments at a clinical level, are presented in this review article, drawing a connection between research findings and related therapeutic strategies aimed at preventing BCBM formation and/or progression. Furthermore, we briefly address the critical limitations in our current understanding of this complex topic, highlighting potential focal points for future research.

Shared decision-making (SDM) has become increasingly important in health care. However, despite scientific evidence, effective implementation strategies, and a prominent position on the health policy agenda, SDM is not widely implemented in routine practice so far. Therefore, we developed a program for routine implementation of SDM in oncology by conducting an analysis of the current state and a needs assessment in a pilot study based on the Consolidated Framework for Implementation Research (CFIR). Based on these results, the main aim of our current study is to evaluate the process and outcome of this theoretically and empirically grounded multicomponent implementation program designed to foster SDM in routine cancer care. We use a stepped wedge design, a variant of the cluster randomized controlled trial. The intervention to be implemented is SDM. Three participating clinics of one comprehensive cancer center will be randomized and receive the multicomponent SDM implementation program in a time-delayed sequence. The program consists of the following strategies: (a) SDM training for health care professionals, (b) individual coaching for physicians, (c) patient activation strategy, (d) provision of patient information material and decision aids, (e) revision of the clinics’ quality management documents, and (f) critical reflection of current organization of multidisciplinary team meetings. We will conduct a mixed methods outcome and process evaluation. The outcome evaluation will consist of four measurement points. The primary outcome is adoption of SDM, measured by the 9-item Shared Decision Making Questionnaire. A range of other implementation outcomes will be assessed (i.e., acceptability, readiness for implementing change, appropriateness, penetration). The implementation process will be evaluated using stakeholder interviews and field notes. This will allow adapting interventions if necessary. This study is the first large study on routine implementation of SDM conducted in German cancer care. We expect to foster implementation of SDM at the enrolled clinics. Insights gained from this study, using a theoretically and empirically grounded approach, can inform other SDM implementation studies and health policy developments, both nationally and internationally. clinicaltrials.gov, NCT03393351 . Registered 8 January 2018.