Arbeitsgemeinschaft Gynäkologische Onkologie Recommendations for the Diagnosis and Treatment of Patients with Early Breast Cancer: Update 2024.

Introduction: Each year the interdisciplinary AGO (Arbeitsgemeinschaft Gynäkologische Onkologie, German Gynecological Oncology Group) Breast Committee on Diagnosis and Treatment of Breast Cancer provides updated state-of-the-art recommendations for early and metastatic breast cancer. Methods: The updated evidence-based treatment recommendations for early and metastatic breast cancer have been released in March 2024. Results and Conclusion: This paper concisely captures the updated recommendations for early breast cancer chapter by chapter.

Arbeitsgemeinschaft Gynäkologische Onkologie Recommendations for the Diagnosis and Treatment of Patients with Locally Advanced and Metastatic Breast Cancer: Update 2024.

The Breast Committee of the Arbeitsgemeinschaft Gynäkologische Onkologie (German Gynecological Oncology Group, AGO) presents the 2024 update of the evidence-based recommendations for the diagnosis and treatment of patients with locally advanced and metastatic breast cancer.

6th and 7th International consensus guidelines for the management of advanced breast cancer (ABC guidelines 6 and 7).

This manuscript describes the Advanced Breast Cancer (ABC) international consensus guidelines updated at the last two ABC international consensus conferences (ABC 6 in 2021, virtual, and ABC 7 in 2023, in Lisbon, Portugal), organized by the ABC Global Alliance. It provides the main recommendations on how to best manage patients with advanced breast cancer (inoperable locally advanced or metastatic), of all breast cancer subtypes, as well as palliative and supportive care. These guidelines are based on available evidence or on expert opinion when a higher level of evidence is lacking. Each guideline is accompanied by the level of evidence (LoE), grade of recommendation (GoR) and percentage of consensus reached at the consensus conferences. Updated diagnostic and treatment algorithms are also provided. The guidelines represent the best management options for patients living with ABC globally, assuming accessibility to all available therapies. Their adaptation (i.e. resource-stratified guidelines) is often needed in settings where access to care is limited.

Update Breast Cancer 2024 Part 1 - Expert Opinion on Advanced Breast Cancer.

Clinical evidence is interpreted based on clinical studies and personal experience which can lead to different interpretations of data. This makes the opinions issued by panels of experts such as the Advanced Breast Cancer Panel which convened in November 2023 for the seventh time (ABC7) particularly important. At the conference, current issues around advanced breast cancer were evaluated by an international team of experts. In 2023 the data on CDK4/6 inhibitors was so extensive that the answers to questions about the sequencing of therapy and the potential use of chemotherapy as an alternative therapy were relatively clear. Moreover, data on antibody drug conjugates which provides a good overview of their uses is available for all molecular subtypes. Some therapeutic settings, including patients with brain metastases or leptomeningeal disease, older patients, locally advanced breast cancer and visceral crises, continue to be particularly important and were discussed in structured sessions. The scientific context of some of the topics discussed at ABC7 is presented and assessed here.

Neoadjuvant pembrolizumab+chemotherapy/adjuvant pembrolizumab for Early-Stage Triple-Negative breast cancer: Quality-of-Life results from randomized KEYNOTE-522 study.

BACKGROUND: In KEYNOTE-522 (NCT03036488), neoadjuvant pembrolizumab+chemotherapy then adjuvant pembrolizumab significantly improved pathological complete response and event-free survival vs neoadjuvant chemotherapy in early-stage triple-negative breast cancer (TNBC). We report patient-reported outcomes (PROs) from KEYNOTE-522. METHODS: Patients were randomized 2:1 to neoadjuvant pembrolizumab 200 mg or placebo every 3 weeks, plus 4 cycles of paclitaxel+carboplatin then 4 cycles of doxorubicin (or epirubicin)+cyclophosphamide. After surgery, patients received adjuvant pembrolizumab or placebo for up to 9 cycles. EORTC QLQ-30 and QLQ-BR23 were prespecified secondary objectives. Between-group differences in least squares (LS) mean change from baseline (day 1/cycle 1 in both neoadjuvant and adjuvant phases) to the prespecified latest time point with ≥60%/80% completion/compliance were assessed using a longitudinal model (no alpha error assigned). RESULTS: Week 21 (neoadjuvant phase) and week 24 (adjuvant phase) were the latest time points at which completion/compliance rates were ≥60%/80%. In the neoadjuvant phase, between-group differences (pembrolizumab+chemotherapy [N = 762] vs placebo+chemotherapy [N = 383]) in LS mean change from baseline to week 21 in QLQ-C30 GHS/QoL, emotional functioning, and physical functioning were -1.04 (95% CI, -3.46 to 1.38), -0.69 (95% CI, -3.13 to 1.75), and -2.85 (95% CI, -5.11 to - 0.60), respectively. In the adjuvant phase, between-group differences (pembrolizumab [N = 539] vs placebo [N = 308]) in LS mean change from baseline to week 24 were -0.41 (95% CI, -2.60 to 1.77), -0.60 (95% CI, -2.99 to 1.79), and -1.57 (95% CI, -3.36 to 0.21). CONCLUSIONS: No substantial differences in PRO assessments were observed between neoadjuvant pembrolizumab+chemotherapy followed by adjuvant pembrolizumab vs neoadjuvant placebo+chemotherapy in early-stage TNBC. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03036488.

Evaluation of the Impact of Adaptive Progressive Supervised Resistance Training on Strength and Quality of Life in Patients with Breast Cancer during Chemotherapy: The VALESCO Study.

INTRODUCTION: Breast cancer patients (BCP) experience considerable side effects during and after treatment. Several studies have shown positive effects of exercise on therapy-related side-effects such as loss of muscle strength, loss of bone mineral density, lymphedema, and several elements of quality of life (QoL). Resistance exercise has proven effective and beneficial for BCP; however, optimal individual training parameters remain to be determined. METHODS: The aim of our study was to implement an adaptive, progressive, supervised resistance protocol for BCPs during chemotherapy, improving muscle strength, physical condition, and overall QoL while reducing therapy-induced side-effects. Forty patients receiving adjuvant chemotherapy were included 6-12 weeks post-OP. Twenty patients underwent high intensity resistance-training twice a week for 12 weeks, and the control group received usual care. RESULTS: Strength parameters improved significantly in the intervention group and in different scales of QoL. We documented a cyclic performance level dependent on the number of days after treatment. CONCLUSION: Adaptive resistance training with simple training control mechanisms proved to be effective regarding optimal intensity in each training session and needs to be implemented in further studies in order to guarantee adequate loads in accordance to the training protocols.

App-based support for breast cancer patients to reduce psychological distress during therapy and survivorship - a multicentric randomized controlled trial.

Introduction: The negative impact of unmanaged psychological distress on quality of life and outcome in breast cancer survivors has been demonstrated. Fortunately, studies indicate that distress can effectively be addressed and even prevented using evidence-based interventions. In Germany prescription-based mobile health apps, known as DiGAs (digital health applications), that are fully reimbursed by health insurances, were introduced in 2020. In this study, the effectiveness of an approved breast cancer DiGA was investigated: The personalized coaching app PINK! Coach supports and accompanies breast cancer patients during therapy and follow-up. Methods: PINK! Coach was specifically designed for breast cancer (BC) patients from the day of diagnosis to the time of Follow-up (aftercare). The app offers individualized, evidence-based therapy and side-effect management, mindfulness-based stress reduction, nutritional and psychological education, physical activity tracking, and motivational exercises to implement lifestyle changes sustainably in daily routine. A prospective, intraindividual RCT (DRKS00028699) was performed with n = 434 patients recruited in 7 German breast cancer centers from September 2022 until January 2023. Patients with BC were included independent of their stage of diseases, type of therapy and molecular characteristics of the tumor. Patients were randomized into one of two groups: The intervention group got access to PINK! over 12 weeks; the control group served as a waiting-list comparison to "standard of care." The primary endpoint was psychological distress objectified by means of Patient Health Questionnaire-9 (PHQ-9). Subgroups were defined to investigate the app's effect on several patient groups such as MBC vs. EBC patients, patients on therapy vs. in aftercare, patients who received a chemotherapy vs. patients who did not. Results: Efficacy analysis of the primary endpoint revealed a significant reduction in psychological distress (least squares estimate -1.62, 95% confidence interval [1.03; 2.21]; p<0.001) among intervention group patients from baseline to T3 vs, control group. Subgroup analysis also suggested improvements across all clinical situations. Conclusion: Patients with breast cancer suffer from psychological problems including anxiety and depression during and after therapy. Personalized, supportive care with the app PINK! Coach turned out as a promising opportunity to significantly improve psychological distress in a convenient, accessible, and low-threshold manner for breast cancer patients independent of their stage of disease (EBC/MBC), therapy phase (aftercare or therapy) or therapy itself (chemotherapy/other therapy options). The app is routinely available in Germany as a DiGA. Clinical Trial Registration: DRKS Trial Registry (DRKS00028699).

Discussion of ABC7 Consensus and German Recommendations.

The rationale behind the "International Consensus Conference for Advanced Breast Cancer" (ABC) is to standardize the treatment of patients with advanced or metastatic breast cancer worldwide using an evidence-based approach. The aim is also to ensure that patients in all countries receive adequate treatment based on current treatment recommendations and standards. The 7th International Consensus Conference on Advanced Breast Cancer (ABC7) took place from November 9 to 12, 2023 in Lisbon/Portugal. ABC7 focused on metastatic disease as well as on locally advanced and inflammatory breast cancer. Special topics included the treatment of oligometastatic patients, leptomeningeal disease, treatment of brain metastases, and pregnant women with ABC. As in previous years, patient advocates from all over the world participated in the consensus conference and were involved in decision making.

Integration of Pathological Criteria and Immunohistochemical Evaluation for Invasive Lobular Carcinoma Diagnosis: Recommendations From the European Lobular Breast Cancer Consortium.

Invasive lobular carcinoma (ILC) is the second most frequent type of breast cancer (BC) and its peculiar morphology is mainly driven by inactivation of CDH1, the gene coding for E-cadherin cell adhesion protein. ILC-specific therapeutic and disease-monitoring approaches are gaining momentum in the clinic, increasing the importance of accurate ILC diagnosis. Several essential and desirable morphologic diagnostic criteria are currently defined by the World Health Organization, the routine use of immunohistochemistry (IHC) for E-cadherin is not recommended. Disagreement in the diagnosis of ILC has been repeatedly reported, but interpathologist agreement increases with the use of E-cadherin IHC. In this study, we aimed to harmonize the pathological diagnosis of ILC by comparing 5 commonly used E-cadherin antibody clones (NCH-38, EP700Y, Clone 36, NCL-L-E-cad [Clone 36B5], and ECH-6). We determined their biochemical specificity for the E-cadherin protein and IHC staining performance according to type and location of mutation on the CDH1 gene. Western blot analysis on mouse cell lines with conditional E-cadherin expression revealed a reduced specificity of EP700Y and NCL-L-E-cad for E-cadherin, with cross-reactivity of Clone 36 to P-cadherin. The use of IHC improved interpathologist agreement for ILC, lobular carcinoma in situ, and atypical lobular hyperplasia. The E-cadherin IHC staining pattern was associated with variant allele frequency and likelihood of nonsense-mediated RNA decay but not with the type or position of CDH1 mutations. Based on these results, we recommend the indication for E-cadherin staining, choice of antibodies, and their interpretation to standardize ILC diagnosis in current pathology practice.

ABC7 Consensus: Assessment by a German Group of Experts.

Background: The "International Consensus Conference for Advanced Breast Cancer" was initiated more than 10 years ago. The rationale was to standardize treatment of advanced breast cancer (ABC) based on available evidence and to ensure that all ABC patients worldwide receive adequate treatment and access to new therapies. Topics of ABC7: The 7th International Consensus Conference for ABC (ABC7) took place from November 9 to 11, 2023 - as in previous years in Lisbon/Portugal. ABC7 focused not only on metastatic disease but also on locally advanced and inflammatory breast cancer. Special topics were the management of oligometastatic disease, leptomeningeal disease, brain metastases, and pregnant women with ABC. Due to the current situation worldwide, there was a special interest to patients living in conflict zones. As in previous years, patient advocates from around the world were integrated into the ABC conference and had a major input to the consensus. Rationale for the Manuscript: A German breast cancer expert panel comments on the voting results of the ABC7 panelists regarding their relevance for routine clinical practice in Germany. As with previous meetings, the ABC7 votes focused on modified or new statements. Regarding the statements not modified for the ABC7 consensus, they are discussed in the published manuscript from 2021 in which the German experts commented on the ABC6 consensus. The German comments are always based on the current recommendations of the "Breast Committee" of the Gynecological Oncology Working Group (Arbeitsgemeinschaft Gynäkologische Onkologie, AGO Mamma).

TROPION-Breast03: a randomized phase III global trial of datopotamab deruxtecan ± durvalumab in patients with triple-negative breast cancer and residual invasive disease at surgical resection after neoadjuvant therapy.

Background: Despite advances in the treatment of early triple-negative breast cancer (TNBC), patients with residual invasive disease after neoadjuvant therapy have a high risk of disease recurrence and worse survival outcomes than those who have pathological complete response (pCR). Improving outcomes in early TNBC remains an unmet need requiring new adjuvant treatment approaches. Datopotamab deruxtecan (Dato-DXd) is an antibody-drug conjugate comprising a humanized anti-trophoblast cell-surface antigen 2 immunoglobulin G1 (IgG1) monoclonal antibody attached via a plasma-stable, cleavable linker to a potent topoisomerase I inhibitor payload, with activity observed in advanced TNBC. Objectives: TROPION-Breast03 is an ongoing phase III study evaluating the efficacy and safety of Dato-DXd alone or combined with durvalumab versus standard-of-care therapy as adjuvant treatment in patients with stage I-III TNBC with residual invasive disease at surgical resection following neoadjuvant treatment. Methods and design: Eligible patients, aged ⩾18 years, will be randomized in a 2:1:2 ratio to receive Dato-DXd [6 mg/kg intravenously (IV) every 3 weeks (Q3W); eight cycles] and durvalumab (1120 mg IV Q3W; nine cycles), Dato-DXd monotherapy (6 mg/kg IV Q3W), or investigator's choice of therapy (ICT; capecitabine, pembrolizumab, or capecitabine and pembrolizumab). The primary endpoint is invasive disease-free survival (iDFS) for Dato-DXd and durvalumab versus ICT. Key secondary endpoints include safety, distant disease-free survival, and overall survival for Dato-DXd and durvalumab versus ICT and iDFS for Dato-DXd monotherapy versus ICT. Ethics: TROPION-Breast03 will be approved by the independent ethics committees or institutional review boards at each study site. All study participants will provide written informed consent. Discussion: TROPION-Breast03 will help define the potential role of Dato-DXd in the treatment of patients with early-stage TNBC who do not have pCR after neoadjuvant therapy. Trial registration: ClinicalTrials.gov identifier: NCT05629585 (registration date: 29 November 2022).

TROPION-Breast03: a clinical trial designed to assess the effectiveness and safety of Dato-DXd, alone or in combination with durvalumab, in patients with triple-negative breast cancer who have cancer cells remaining at the time of surgery after initial systemic therapy Triple-negative breast cancer (TNBC), in which cells do not have estrogen or progesterone receptors or high levels of human epidermal growth factor receptor 2, is the most aggressive breast cancer subtype. TNBC is difficult to treat and associated with high risk of recurrence despite standard systemic therapy (treatment targeting the entire body), which can include chemotherapy alone or in combination with immunotherapy (treatment targeting the immune system). To reduce the risk of recurrence, standard systemic treatment is often followed by surgical removal of the patient's tumors and additional systemic treatment. Dato-DXd is an antibody-drug conjugate, which is an anticancer drug (DXd) connected to an antibody (datopotamab) by a stable linker. Datopotamab binds to TROP2, a protein found on breast cancer cells, and is taken into the tumor cell where the linker breaks, releasing DXd to kill the cell. By delivering DXd directly to cancer cells, Dato-DXd reduces exposure in the rest of the body, reducing the risk of side effects. Since Dato-DXd can recruit immune cells to cancer sites, it may work better combined with durvalumab, a drug that blocks the activity of a protein called PD-L1, making cancer cells more susceptible to being killed by immune cells. The TROPION-Breast03 study will compare Dato-DXd, alone or combined with durvalumab, with standard-of-care therapy in patients with TNBC that has not spread to parts of the body away from the original tumor site(s), but with cancer cells remaining at the time of surgery after initial systemic therapy. It will assess how well each treatment works and describe any side effects. We plan to recruit 1,075 eligible adults who will be randomly assigned in a 2:1:2 ratio to: • Dato-DXd + durvalumab • Dato-DXd alone • Standard-of-care therapy • Patients will receive treatment until they complete the planned course of therapy (8 or 9 cycles), their cancer returns, side effects become unacceptable, or they choose to stop.

Impact of dose reductions on adjuvant abemaciclib efficacy for patients with high-risk early breast cancer: analyses from the monarchE study.

In monarchE, adjuvant abemaciclib significantly improved invasive disease-free survival (IDFS) and distant relapse-free survival (DRFS), with sustained benefit beyond the 2-year treatment period. Abemaciclib dose reductions were allowed to proactively manage adverse events. Exploratory analyses to investigate the impact of dose reductions on efficacy were conducted. Across the three patient subgroups as defined by relative dose intensity (≤66%, 66-93%, ≥93%), the estimated 4-year IDFS rates were generally consistent (87.1%, 86.4%, and 83.7%, respectively). In the time-dependent Cox proportional hazard model, the effect of abemaciclib was consistent at the full dose compared to being reduced to a lower dose (IDFS hazard ratio: 0.905; 95% confidence interval: 0.727, 1.125; DRFS hazard ratio: 0.942; 95% confidence interval: 0.742, 1.195). These analyses showed that the efficacy of adjuvant abemaciclib was not compromised by protocol mandated dose reductions for patients with node positive, hormone receptor positive, human epidermal growth factor 2-negative, high-risk early breast cancer.

Assessing Knowledge, Competence, and Performance Following Web-Based Education on Early Breast Cancer Management: Health Care Professional Questionnaire Study and Anonymized Patient Records Analysis.

BACKGROUND: Web-based learning activities are key components of continuing medical education (CME) for health care professionals (HCPs). However, the published outcomes of web-based educational interventions for early breast cancer (EBC) are limited. OBJECTIVE: This study aims to objectively assess knowledge, competence, and performance among HCPs following participation in 2 EBC-focused CME activities and to identify the remaining educational gaps. METHODS: We developed 2 CME-accredited web-based educational activities addressing high-risk EBC, including integration of shared decision-making to optimize patient care (touchMDT) and stratification for early identification of high-risk patients and novel treatment strategies (touchPANEL DISCUSSION). Knowledge, competence, and performance were assessed before and after the activities against an expanded outcomes framework (levels 1-5) using self-reported questionnaires and an analysis of anonymized data extracted from patient records. RESULTS: Six months after the launch of the activity, 7047 and 8989 HCP participants engaged with touchMDT and touchPANEL DISCUSSION, respectively. The overall satisfaction was 82% (a total score of 20.6 out of 25) for the touchMDT and 88% (a total score of 21.9 out of 25) for the touchPANEL DISCUSSION. For the evaluation of knowledge and competence (50 respondents before the activity and 50 learners after the activity), there was a significant increase in the mean number of correctly answered questions from pre- to postactivity (touchMDT: median 4.0, IQR 3.0-5.0 to median 5.5, IQR 4.0-7.0; mean 4.00, SD 1.39 to mean 5.30, SD 1.56 and touchPANEL DISCUSSION: median 4.0, IQR 4.0-5.0 to median 6.0, IQR 5.0-7.0; mean 4.32, SD 1.30 to mean 5.88, SD 1.49; both P<.001). A significant improvement in self-reported performance (50 respondents before the activity and 50 learners after the activity) was observed in a combined analysis of both activities (median 3.0, IQR 2.0-3.0 to median 4.0, IQR 3.0-5.0; mean 2.82, SD 1.08 to mean 4.16, SD 1.45; P<.001). Patient record analysis (50 respondents before the activity and 50 learners after the activity) showed that the HCPs used a range of measures to determine EBC recurrence risk and revealed no significant differences in adjuvant therapies used before and after the activity (P=.97 and P>.99 for Ki-67 <20% and Ki-67 ≥20% tumors, respectively). The remaining educational gaps included strategies for implementing shared decision-making in clinical practice and the use of genetic and biomarker testing to guide treatment selection. CONCLUSIONS: Brief, web-based CME activities on EBC were associated with an improvement in HCP knowledge, competence, and self-reported performance and can help identify unmet needs to inform the design of future CME activities.

App-Based Lifestyle Intervention (PINK! Coach) in Breast Cancer Patients-A Real-World-Data Analysis.

INTRODUCTION: Overweight and a lack of physical activity not only increase the risk of recurrence in breast cancer patients but also negatively impact overall and long-term survival, as well as quality of life. The results presented here are the first real-world data from the DiGA PINK! Coach examining the physical activity and BMI of app users. Based on the literature, an approximate weight gain of 10% over 6 months and a decrease in physical activity can be expected. The purpose of this study is to retrospectively investigate the effects of the PINK! Coach in a real-world setting on patients' BMI and physical activity level during acute therapies. such as chemotherapy (CHT) and antihormone therapy (AHT). MATERIAL AND METHODS: The PINK! Coach app accompanies breast cancer patients during and after acute therapy to bring about a sustainable lifestyle change. The patients are encouraged to establish a healthy diet, become physically active, and make informed decisions. In this study, real-world data from the app were analyzed over 6 months from baseline to T1 (after 12 weeks) and T2 (after 24 weeks). The patients were under acute therapy or in follow-up care receiving either CHT or AHT. RESULTS: The analyzed data indicate that all patients were able to maintain a consistent BMI over 6 months independent of pre-defined subgroups such as AHT, CHT, or BMI subgroups. In the subgroup of patients undergoing AHT, overweight patients were even able to significantly reduce their BMI by 1-score-point over 6 months (p < 0.01). The subgroup of patients undergoing CHT also showed an significant overall reduction in BMI (p = 0.01). All patients were also able to significantly increase their daily step count as well as their physical activity minutes per day. After the first 12 weeks, 41.4% of patients experienced weight gain, 33.4% were able to maintain their weight, and 24.2% reduced their weight. CONCLUSION: The presented data provides intriguing insights into the users of the PINK! Coach app and the impact of this usage in regards to BMI and physical activity. At the current time, there are only a few effective concepts for encouraging all breast cancer patients to engage in moderate physical activity and reduce body weight. Often, these concepts apply to selected patient groups. The data presented here include all age groups, tumor stages, and therapies, providing an initial insight into a comprehensive approach. Data over an even longer period would be one way to better contextualize the results in current research.

Radiotherapy statements of the 18th St. Gallen International Breast Cancer Consensus Conference-a German expert perspective.

PURPOSE: To summarize the radiotherapy-relevant statements of the 18th St. Gallen Breast Cancer Consensus Conference and interpret the findings in light of German guideline recommendations. METHODS: Statements and voting results from the 18th St. Gallen International Breast Cancer Consensus Conference were collected and analyzed according to their relevance for the radiation oncology community. The voting results were discussed in two hybrid meetings among the authors of this manuscript on March 18 and 19, 2023, in light of the German S3 guideline and the 2023 version of the Arbeitsgemeinschaft Gynäkologische Onkologie (AGO) guidelines. RESULTS AND CONCLUSION: There was a high level of agreement between the radiotherapy-related statements of the 18th St. Gallen International Breast Cancer Consensus Conference and the German S3 and AGO guidelines. Discrepancies include the impact of number of lymph node metastases for the indication for postmastectomy radiotherapy.

Filgrastim biosimilar (EP2006): A review of 15 years' post-approval evidence.

Filgrastim is approved for several indications, including reduction of the incidence and duration of chemotherapy-induced neutropenia and for stem cell mobilization. The filgrastim biosimilar, EP2006, has been available in Europe since 2009, and in the United States since 2015. In this time, preclinical and clinical data used to support the approval of EP2006 have been published. These data established the biosimilarity of EP2006 to reference filgrastim in terms of structure, pharmacokinetics, pharmacodynamics, efficacy, safety, and immunogenicity. Additional real-world evidence studies have also demonstrated equivalent efficacy and safety of EP2006 compared with reference filgrastim, both in the reduction of neutropenia and in stem cell mobilization in clinical practice. This review summarizes these preclinical, clinical, and real-world data, as well as the available cost-effectiveness data, for EP2006 since its approval 15 years ago.

International multidisciplinary consensus on the integration of radiotherapy with new systemic treatments for breast cancer: European Society for Radiotherapy and Oncology (ESTRO)-endorsed recommendations.

Novel systemic therapies for breast cancer are being rapidly implemented into clinical practice. These drugs often have different mechanisms of action and side-effect profiles compared with traditional chemotherapy. Underpinning practice-changing clinical trials focused on the systemic therapies under investigation, thus there are sparse data available on radiotherapy. Integration of these new systemic therapies with radiotherapy is therefore challenging. Given this rapid, transformative change in breast cancer multimodal management, the multidisciplinary community must unite to ensure optimal, safe, and equitable treatment for all patients. The aim of this collaborative group of radiation, clinical, and medical oncologists, basic and translational scientists, and patient advocates was to: scope, synthesise, and summarise the literature on integrating novel drugs with radiotherapy for breast cancer; produce consensus statements on drug-radiotherapy integration, where specific evidence is lacking; and make best-practice recommendations for recording of radiotherapy data and quality assurance for subsequent studies testing novel drugs.

Neratinib as Extended Adjuvant Treatment of HER2-Positive/HR-Positive Early Breast Cancer Patients in Germany, Austria, and Switzerland: Interim Results of the Prospective, Observational ELEANOR Study.

Introduction: Prognosis of patients diagnosed with HER2+ early breast cancer (eBC) has substantially improved, but distant recurrences impacting quality of life and survival still occur. One treatment option for extended adjuvant treatment of patients with HER2+/HR+ eBC is neratinib, available in Europe for patients who completed adjuvant trastuzumab-based therapy within 1 year. The ELEANOR study is investigating the real-world use of neratinib in Germany, Austria, and Switzerland. Results from an interim analysis of the first 200 patients observed for ≥3 months are reported. Methods: The primary objective of this prospective, multicenter, observational study is to assess patient adherence to neratinib (defined as the percentage of patients taking neratinib on ≥75% prescribed days). Secondary objectives are patient characteristics and treatment outcomes. Results: At cut-off (May 2, 2022), a total of 202 patients had been observed for ≥3 months, with neratinib treatment documented for 187 patients (median age: 53.0 years; 67.9% at increased risk of disease recurrence). In total, 151 (80.7%) patients had received prior neoadjuvant treatment; of these, 82 (54.3%) patients achieved a pathologically complete response. Neratinib was initiated at a median 3.6 months after trastuzumab-based treatment, with 36.4% starting at a dose <240 mg/day. Treatment is ongoing for 46.0% of patients, with median treatment duration of 11.2 (interquartile range 0.9-12.0) months. Diarrhea was the most common adverse event (78.6% any grade, 20.3% grade ≥3); pharmacologic prophylaxis was used in 85.6% of patients. Conclusions: The pattern of anti-HER2 pretreatment observed reflected the current treatment for HER2+/HR+ eBC in Germany, Austria, and Switzerland. These interim results suggest that neratinib as an extended adjuvant is a feasible option after various anti-HER2 pretreatments and that its tolerability can be managed and improved with proactive diarrhea management.

Use of the Gene Expression Test Prosigna® in Premenopausal Patients with HR+, HER2- Early Breast Cancer: Correlation of the Results with the Proliferation Marker Ki-67.

Introduction: In hormone receptor-positive (ER+/PR+) and human epidermal growth factor receptor 2-negative (HER2-) early-stage breast cancer (EBC), gene expression tests such as the Prosigna are increasingly used since classic clinicopathological parameters and the proliferation factor Ki-67 often do not allow a definite therapy decision regarding an adjuvant chemotherapy. While the Prosigna test has been validated for postmenopausal patients, few data are available regarding its use in premenopausal patients. The present study compared the Prosigna test with the Ki-67 index in premenopausal patients. Materials and Methods: Premenopausal patients with HR+ HER2-, pN0-1, G1-2 EBC were retrospectively enrolled (n = 55). The Prosigna assay was performed in formalin-fixed paraffin-embedded tumor samples of surgical resection specimens. Ki-67 was reassessed in original diagnostic core needle biopsy specimens and defined as low, intermediate, or high with the threshold of <10%, 10-24%, ≥25%. Results: According to Ki-67, patients were in the low (LR)-, intermediate (IR)-, and high-risk (HR) groups in 40%, 36%, and 24% of the cases. The Prosigna gene signature assay assessed the risk of recurrence as LR for 45% of the patients, IR for 35%, and HR for 20%. The most frequent intrinsic subtypes were luminal A in 73% and luminal B in 24% of the patients. A moderate correlation was found between Prosigna and Ki-67 scores with a Pearson correlation coefficient of 0.51. In the overall cohort, 47% of the Ki-67-based therapy decision would correspond to those based on the Prosigna score. After exclusion of IR patients, matching of low/low or high/high results was observed in 57% of the cases. Conclusion: According to the present study, there is only limited concordance regarding the risk group stratification between Ki-67 and Prosigna-based risk assessment. The relevance and frequency of premenopausal breast cancer emphasizes the need for further evaluation of gene expression analyses in this setting and the correlation with classic clinicopathological parameters regarding therapy decision-making.