AGO Recommendations for the Diagnosis and Treatment of Patients with Early Breast Cancer: Update 2021

Small animal PET imaging with the 68Ga-labeled pH (low) insertion peptide-like peptide YJL-4 in a triple-negative breast cancer mouse model

BACKGROUND

The aim of this study was to prepare a novel 68Ga-labeled pH (low) insertion peptide (pHLIP)-like peptide, YJL-4, and determine its value for the early diagnosis of triple-negative breast cancer (TNBC) via in vivo imaging of tumor-bearing nude mice. The novel peptide YJL-4 was designed using a template-assisted method and synthesized by solid-phase peptide synthesis. After modification with the chelator 1,4,7‑triazacyclononane-N,N',N″-triacetic acid (NOTA), the peptide was labeled with 68Ga. Then, the biodistribution of 68Ga-YJL-4 in tumor-bearing nude mice was investigated, and the mice were imaged by small animal positron emission tomography (PET).

RESULTS

The radiochemical yield and radiochemical purity of 68Ga-YJL-4 were 89.5 ± 0.16% and 97.95 ± 0.06%, respectively. The biodistribution of 68Ga-YJL-4 in tumors (5.94 ± 1.27% ID/g, 6.72 ± 1.69% ID/g and 4.54 ± 0.58% ID/g at 1, 2 and 4 h after injection, respectively) was significantly greater than that of the control peptide in tumors at the corresponding time points (P < 0.01). Of the measured off-target organs, 68Ga-YJL-4 was highly distributed in the liver and blood. The small animal PET imaging results were consistent with the biodistribution results. The tumors were visualized by PET at 2 and 4 h after the injection of 68Ga-YJL-4. No tumors were observed in the control group.

CONCLUSIONS

The novel pHLIP family peptide YJL-4 can adopt an α-helical structure for easy insertion into the cell membrane in an acidic environment. 68Ga-YJL-4 was produced in high radiochemical yield with good stability and can target TNBC tissue. Moreover, the strong concentration of radioactive 68Ga-YJL-4 in the abdomen does not hinder the imaging of early TNBC.

Association between 21-gene-assay and detection of disseminated tumor cells in patients with early breast cancer: results from the IRMA trial

PURPOSE

Disseminated tumor cells (DTCs) in the bone marrow (BM) are known to be of prognostic value for patients with early breast cancer (EBC). In addition to histopathological features, multigene expression assays, such as the commercially available 21-gene Breast Recurrence Score® assay, have been validated for evaluating prognosis and making decisions concerning adjuvant treatment in EBC. In a previous retrospective study from our group, the 21-gene assay was shown to be associated with DTC-detection. A secondary endpoint of the prospective IRMA trial was to evaluate the association between Recurrence Score® (RS) result and tumor cell dissemination in patients with EBC.

METHODS

DTC-status and RS result were assessed in patients with ER-positive/HER2-negative EBC with 0-3 pathologic lymph nodes who underwent primary surgical treatment at the Department for Women's Health of Tuebingen University, Germany.

RESULTS

Patients with a high RS result (≥ 26) were more frequently DTC-positive (22.6%) than patients with a low RS result (8.6%, p = 0.034). The odds for DTC-positivity increased with rising RS values (p = 0.047).

CONCLUSION

We therefore confirm that a high genomic risk is associated with tumor cell dissemination into the BM. Further trials are needed to investigate whether therapeutic decisions could be further individualized by combining DTC-status and prognostic gene signature testing.

Update Breast Cancer 2023 Part 3 - Expert Opinions of Early Stage Breast Cancer Therapies

The St. Gallen (SG) International Breast Cancer Conference is held every two years, previously in St. Gallen and now in Vienna. This year (2023) marks the eighteenth edition of this conference, which focuses on the treatment of patients with early-stage breast carcinoma. A panel discussion will be held at the end of this four-day event, during which a panel of experts will give their opinions on current controversial issues relating to the treatment of early-stage breast cancer patients. To this end, questions are generally formulated in such a way that clinically realistic cases are presented - often including poignant hypothetical modifications. This review reports on the outcome of these discussions and summarises the data associated with individual questions raised.

Update Breast Cancer 2023 Part 2 - Advanced-Stage Breast Cancer

In recent years, a number of new therapies have led to advances in the treatment of patients with advanced breast carcinoma. These substances are mainly CDK4/6 inhibitors and other substances that can overcome endocrine resistance, oral selective estrogen receptor degraders, antibody drug conjugates (ADCs), and PARP inhibitors. This review summarizes and evaluates the latest study results that have been published in recent months. This includes the overall survival data of the Destiny-Breast03 study, the first analysis of the CAPItello-291 study, the comparison of CDK4/6 inhibitor treatment with chemotherapy in the first line of therapy (RIGHT Choice study), the first analysis of the Destiny-Breast02 study in the treatment setting after T-DM1 treatment, and the first analysis of the Serena-2 study. Most of these studies have the potential to significantly change the therapeutic landscape for patients with advanced breast carcinoma and show that the continued rapid development of new therapies is always producing new results.

Systemic Therapy of Premenopausal Patients with Early Stage Hormone Receptor-Positive, HER2-Negative Breast Cancer - Controversies and Standards in Healthcare

In patients with existing ovarian function, there are some special aspects to adjuvant endocrine therapy in premenopausal patients with hormone receptor-positive, HER2-negative (HR pos./HER2 neg.) breast cancer. Treatment options include tamoxifen with or without a GnRH analog, and aromatase inhibitors with a GnRH analog. Furthermore, ovarian function is affected by previous chemotherapy. Both aromatase inhibitors (+GnRH analogs) and GnRH analogs in combination with tamoxifen are supposed to be indicated for patients at increased risk of recurrence. However, national and international guidelines and therapy recommendations do not provide a clear definition of intermediate or high risk; as a result, therapy decisions are often made for each patient on an individual basis. This is also reflected in the considerable variability at national and international levels, e.g., with regard to the use of aromatase inhibitors + GnRH analogs. This review summarizes the data on completed studies (e.g., SOFT, TEXT, EBCTCG meta-analyses) and the current multigene testing studies (TailorX, RxPonder, ADAPT), discusses the rationale for current studies (e.g., CLEAR-B), and looks ahead to future questions.

Pegylated liposomal doxorubicin (Duomeisu(®)) monotherapy in patients with HER2-negative metastatic breast cancer heavily pretreated with anthracycline and taxanes: a single-arm, phase II study

PURPOSE

To evaluate the efficacy and safety of pegylated liposomal doxorubicin (PLD) in patients with human epidermal growth factor receptor 2 (HER2)-negative metastatic breast cancer (MBC) heavily pretreated with anthracycline and taxanes.

METHODS

In this single-arm, phase II study, patients with HER2-negative MBC previously treated with anthracycline and taxanes as second- to fifth chemotherapy received PLD (Duomeisu^®, generic doxorubicin hydrochloride liposome) 40 mg/m² every 4 weeks until disease progression, unacceptable toxicity, or completion of six cycles. Primary endpoint was progression-free survival (PFS). Secondary endpoints included overall survival (OS), objective response rate (ORR), disease control rate (DCR), clinical benefit rate (CBR), and safety.

RESULTS

Of 44 enrolled patients (median age, 53.5 years; range, 34-69), 41 and 36 were evaluable for safety and efficacy, respectively. In total, 59.1% (26/44) of patients had ≥ 3 metastatic sites, 86.4% (38/44) had visceral disease, and 63.6% (28/44) had liver metastases. Median PFS was 3.7 months (95% confidence interval [CI] 3.3-4.1) and median OS was 15.0 months (95% CI 12.1-17.9). ORR, DCR, and CBR were 16.7%, 63.9%, and 36.1%, respectively. The most common adverse events (AEs) were leukopenia (53.7%), fatigue (46.3%), and neutropenia (41.5%), with no grade 4/5 AEs. The most common grade 3 AEs were neutropenia (7.3%) and fatigue (4.9%). Patients experienced palmar-plantar-erythrodysesthesia (24.4%, 2.4% grade 3), stomatitis (19.5%, 7.3% grade 2), and alopecia (7.3%). One patient displayed a left ventricular ejection fraction decline of 11.4% from baseline after five cycles of PLD therapy.

CONCLUSION

PLD (Duomeisu^®) 40 mg/m² every 4 weeks was effective and well-tolerated in patients with HER2-negative MBC heavily pretreated with anthracycline and taxanes, revealing a potentially viable treatment option for this population. Trial registration Chinese Clinical Trial Registry: ChiCTR1900022568.

Review of the status of neoadjuvant therapy in HER2-positive breast cancer

Purpose

The development of human epidermal growth factor receptor 2 (HER2)-directed therapies has revolutionized the treatment of HER2-positive breast cancer. The aim of this article is to review the continually evolving treatment strategies in the neoadjuvant setting of HER2-positive breast cancer, as well as the current challenges and future perspectives.

Methods

Searches were undertaken on PubMed and Clinicaltrials.gov for relevant publications and trials.

Findings

The current standard of care in high-risk HER2-positive breast cancer is to combine chemotherapy with dual anti-HER2 therapy, for a synergistic anti-tumor effect. We discuss the pivotal trials which led to the adoption of this approach, as well as the benefit of these neoadjuvant strategies for guiding appropriate adjuvant therapy. De-escalation strategies are currently being investigated to avoid over treatment, and aim to safely reduce chemotherapy, while optimizing HER2-targeted therapies. The development and validation of a reliable biomarker is essential to enable these de-escalation strategies and personalization of treatment. In addition, promising novel therapies are currently being explored to further improve outcomes in HER2-positive breast cancer.

Recent Advances in Optimizing Radiation Therapy Decisions in Early Invasive Breast Cancer

Adjuvant whole breast irradiation after breast-conserving surgery is a well-established treatment standard for early invasive breast cancer. Screening, early diagnosis, refinement in surgical techniques, the knowledge of new and specific molecular prognostic factors, and now the standard use of more effective neo/adjuvant systemic therapies have proven instrumental in reducing the rates of locoregional relapses. This underscores the need for reliably identifying women with such low-risk disease burdens in whom elimination of radiation from the treatment plan would not compromise oncological safety. This review summarizes the current evidence for radiation de-intensification strategies and details ongoing prospective clinical trials investigating the omission of adjuvant whole breast irradiation in molecularly defined low-risk breast cancers and related evidence supporting the potential for radiation de-escalation in HER2+ and triple-negative clinical subtypes. Furthermore, we discuss the current evidence for the de-escalation of regional nodal irradiation after neoadjuvant chemotherapy. Finally, we also detail the current knowledge of the clinical value of stromal tumor-infiltrating lymphocytes and liquid-based biomarkers as prognostic factors for locoregional relapse.

Linac-Based Ultrahypofractionated Partial Breast Irradiation (APBI) in Low-Risk Breast Cancer: First Results of a Monoinstitutional Observational Analysis

Purpose: For adjuvant radiotherapy of low-risk breast cancer after breast-conserving surgery, there have been many trials of hypofractionation and partial breast irradiation (PBI) over the years, with proven mild long-term toxicity. The aim of this study was to introduce a short-course dose-adapted concept, proven in whole breast irradiation (WBI) for use in accelerated partial breast irradiation (APBI), while monitoring dosimetric data and toxicity. Methods: From April 2020 to March 2022, 61 patients with low-risk breast cancer or ductal carcinoma in situ (DCIS) were treated at a single institution with percutaneous APBI of 26 Gy in five fractions every other day after breast-conserving surgery. Dosimetric data for target volume and organs at risk were determined retrospectively. Acute toxicity was evaluated. Results: The target volume of radiotherapy comprised an average of 19% of the ipsilateral mamma. The burden on the heart and lungs was very low. The mean cardiac dose during irradiation of the left breast was only 0.6 Gy. Two out of three patients remained without any acute side effects. Conclusions: Linac-based APBI is an attractive treatment option for patients with low-risk breast cancer in whom neither WBI nor complete omission of radiotherapy appears to be an adequate alternative.

[Triple-negative breast cancer : Classification, current concepts, and therapy-related factors]

Triple-negative breast cancer (TNBC) accounts for about 10% of all breast cancer cases and is defined by the lack of expression of estrogen and progesterone receptors and the lack of overexpression or amplification of HER2. It differs with regard to the younger age of the patients, an increased association with a mutation of BRCA1 and a mostly low differentiation from hormone receptor-positive breast cancer. The spectrum of triple-negative breast cancer shows considerable heterogeneity both at the morphological and at the molecular level. It includes most commonly TNBC of no special type, with and without basal phenotype, triple-negative metaplastic breast carcinomas, triple-negative breast carcinomas with apocrine differentiation and rare triple-negative tumor types. At the gene-expression level, TNBC most commonly is associated with a basal phenotype, with rarer molecular variants of TNBC involving the Claudin-low, molecular apocrine types, and other rarer subtypes. Therefore, a critical use of the term TNBC, considering the histopathological tumor differentiation, is recommended.

Effects of exercise interventions on cancer-related fatigue in breast cancer patients: an overview of systematic reviews

OBJECTIVE

This overview of systematic reviews aims to critically appraise and consolidate evidence from current systematic reviews (SRs)/meta-analyses on the effects of exercise interventions on cancer-related fatigue (CRF) in breast cancer patients.

METHODS

SRs/meta-analyses that explored the effects of exercise interventions on CRF in breast cancer patients compared with the routine methods of treatment and care were retrieved from nine databases. The methodological quality of the included SRs was appraised using A MeaSurement Tool to Assess systematic Reviews II (AMSTAR II). The Grading of Recommendations Assessment, Development and Evaluation (GRADE) was used to calculate the grading of outcomes in the included SRs. The exercise type, frequency, duration, and inclusion/absence of supervision were further evaluated with subgroup analyses. The Stata 16.0 software was utilized for data analysis.

RESULTS

Twenty-nine reviews were included. The overall methodological quality and level of evidence of the included reviews were unsatisfactory, with only three reviews rated as high methodological quality and no review identified as high-quality evidence. Moderate certainty evidence indicated that exercise could improve fatigue in breast cancer patients (SMD = - 0.40 [95%CI - 0.58, - 0.22]; P = 0.0001). Subgroup analysis based on the types of exercise showed that yoga (SMD = - 0.30 [95%CI - 0.56, - 0.05]; I2 = 28.7%) and aerobic exercise (SMD = - 0.29 [95%CI - 0.56, - 0.02]; I2 = 16%) had a significantly better effect on CRF in breast cancer patients; exercising for over 6 months (SMD = - 0.88 [95%CI - 1.59, - 0.17]; I2 = 42.7%; P = 0.0001), three times per week (SMD = - 0.77 [95%CI - 1.04, - 0.05]; I2 = 0%; P = 0.0001), and for 30 to 60 min per session (SMD = - 0.81 [95%CI - 1.15, - 0.47]; I2 = 42.3%; P = 0.0001) can contribute to a moderate improvement of CRF. Supervised exercise (SMD = - 0.48 [95%CI - 0.77, - 0.18]; I2 = 87%; P = 0.001) was shown to relieve CRF.

CONCLUSION

Exercise played a favorable role in alleviating CRF in breast cancer. Yoga was recommended as a promising exercise modality for CRF management in the majority of the included studies. Exercising for at least three times per week with 30 to 60 min per session could be recommended as a suitable dosage for achieving improvement in CRF. Supervised exercise was found to be more effective in alleviating CRF than unsupervised exercise. More rigorously designed clinical studies are needed to specify the exact exercise type, duration, frequency, and intensity to have an optimal effect on CRF in breast cancer patients.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: CRD42020219866.

Recurrence Score® Result Impacts Treatment Decisions in Hormone Receptor-Positive, HER2-Negative Patients with Early Breast Cancer in a Real-World Setting-Results of the IRMA Trial

BACKGROUND

Patients with hormone receptor-positive (HR+), HER2-negative (HER2-) early breast cancer (eBC) with a high risk of relapse often undergo adjuvant chemotherapy. However, only a few patients will gain benefit from chemotherapy. Since classical tumor characteristics (grade, tumor size, lymph node involvement, and Ki67) are of limited value to predict chemotherapy efficacy, multigene expression assays such as the Oncotype DX® test were developed to reduce over- and undertreatment. The IRMA trial analyzed the impact of Recurrence Score® (RS) assessment on adjuvant treatment recommendations.

MATERIALS AND METHODS

The RS result was assessed in patients with HR+/HER2- unilateral eBC with 0-3 pathologic lymph nodes who underwent primary surgical treatment at the Department for Women's Health of Tuebingen University, Germany. Therapy recommendations without knowledge of the RS result were compared to therapy recommendations with awareness of the RS result.

RESULTS

In total, 245 patients underwent RS assessment. Without knowledge of the RS result, 92/245 patients (37.6%) would have been advised to receive chemotherapy. After RS assessment, 56/245 patients (22.9%) were advised to undergo chemotherapy. Chemotherapy was waived in 47/92 patients (51.1%) that were initially recommended to receive it. Chemotherapy was added in 11/153 patients (7.2%) that were recommended to not receive it initially.

SUMMARY

Using the RS result to guide adjuvant treatment decisions in HR+/HER2- breast cancer led to a substantial reduction of chemotherapy. In view of the results achieved in prospective studies, the RS result is among other risk-factors suitable for the individualization of adjuvant systemic therapy.

Anti-Hormonal Therapy in Breast Cancer and Its Effect on the Blood-Brain Barrier

The molecular receptor status of breast cancer has implications for prognosis and long-term metastasis. Although metastatic luminal B-like, hormone-receptor-positive, HER2−negative, breast cancer causes brain metastases less frequently than other subtypes, though tumor metastases in the brain are increasingly being detected of this patient group. Despite the many years of tried and tested use of a wide variety of anti-hormonal therapeutic agents, there is insufficient data on their intracerebral effectiveness and their ability to cross the blood-brain barrier. In this review, we therefore summarize the current state of knowledge on anti-hormonal therapy and its intracerebral impact and effects on the blood-brain barrier in breast cancer.

Intraoperative Ultrasound-Guided Excision of Non-Palpable and Palpable Breast Cancer: Systematic Review and Meta-Analysis

Wire-guided localization (WGL) is the most frequently used localization technique in non-palpable breast cancer (BC). However, low negative margin rates, patient discomfort, and the possibility of wire dislocation have been discussed as potential disadvantages, and re-operation due to positive margins may increase relapse risk. Intraoperative ultrasound (IOUS)-guided excision allows direct visualization of the lesion and the resection volume and reduces positive margins in palpable and non-palpable tumors. We performed a systematic review on IOUS in breast cancer and 2 meta-analyses of randomized clinical trials (RCTs). In non-palpable BC, 3 RCTs have shown higher negative margin rates in the IOUS arm compared to WGL. Meta-analysis confirmed a significant difference between IOUS and WGL in terms of positive margins favoring IOUS (risk ratio 4.34, p < 0.0001, I2 = 0%). 41 cohort studies including 3291 patients were identified, of which most reported higher negative margin and lower re-operation rates if IOUS was used. In palpable BC, IOUS was compared to palpation-guided excision in 3 RCTs. Meta-analysis showed significantly higher rates of positive margins in the palpation arm (risk ratio 2.84, p = 0.0047, I2 = 0%). In 13 cohort studies including 942 patients with palpable BC, negative margin rates were higher if IOUS was used, and tissue volumes were higher in palpation-guided cohorts in most studies. IOUS is a safe noninvasive technique for the localization of sonographically visible tumors that significantly improves margin rates in palpable and non-palpable BC. Surgeons should be encouraged to acquire ultrasound skills and participate in breast ultrasound training.

Hair safe study: Effects of scalp cooling on hair preservation and hair regrowth in breast cancer patients receiving chemotherapy - A prospective interventional study

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Scalp cooling significantly reduced chemotherapy-induced-alopecia in breast cancer patients.

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No significant effect regarding regrowth after chemotherapy in scalp cooling group.

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Scalp cooling is more effective in preventing alopecia in patients receiving taxane monotherapy.

Incidental irradiation of the regional lymph nodes during deep inspiration breath-hold radiation therapy in left-sided breast cancer patients: a dosimetric analysis

Background

Radiotherapy using the deep inspiration breath-hold (DIBH) technique compared with free breathing (FB) can achieve substantial reduction of heart and lung doses in left-sided breast cancer cases. The anatomical organ movement in deep inspiration also cause unintended exposure of locoregional lymph nodes to the irradiation field.

Methods

From 2017–2020, 148 patients with left-sided breast cancer underwent breast conserving surgery (BCS) or mastectomy (ME) with axillary lymph node staging, followed by adjuvant irradiation in DIBH technique. Neoadjuvant or adjuvant systemic therapy was administered depending on hormone receptor and HER2-status.

CT scans in FB and DIBH position with individual coaching and determination of the breathing amplitude during the radiation planning CT were performed for all patients. Intrafractional 3D position monitoring of the patient surface in deep inspiration and gating was performed using Sentinel and Catalyst HD 3D surface scanning systems (C-RAD, Catalyst, C-RAD AB, Uppsala, Sweden). Three-dimensional treatment planning was performed using standard tangential treatment portals (6 or 18 MV). The delineation of ipsilateral locoregional lymph nodes was done on the FB and the DIBH CT-scan according to the RTOG recommendations.

Results

The mean doses (D_mean) in axillary lymph node (AL) level I, II and III in DIBH were 32.28 Gy (range 2.87–51.7), 20.1 Gy (range 0.44–53.84) and 3.84 Gy (range 0.25–39.23) vs. 34.93 Gy (range 10.52–50.40), 16.40 Gy (range 0.38–52.40) and 3.06 Gy (range 0.21–40.48) in FB (p < 0.0001). Accordingly, in DIBH the D_mean for AL level I were reduced by 7.59%, whereas for AL level II and III increased by 22.56% and 25.49%, respectively.

The D_mean for the supraclavicular lymph nodes (SC) in DIBH was 0.82 Gy (range 0.23–4.11), as compared to 0.84 Gy (range 0.22–10.80) with FB (p = 0.002). This results in a mean dose reduction of 2.38% in DIBH.

The D_mean for internal mammary lymph nodes (IM) was 12.77 Gy (range 1.45–39.09) in DIBH vs. 11.17 Gy (range 1.34–44.24) in FB (p = 0.005). This yields a mean dose increase of 14.32% in DIBH.

Conclusions

The DIBH technique may result in changes in the incidental dose exposure of regional lymph node areas.

Post-Neoadjuvant Treatment in HER2-Positive Breast Cancer: Escalation and De-Escalation Strategies

Simple Summary

The response to neoadjuvant treatment is strongly associated with the clinical outcome of breast cancer patients, especially in the HER2-positive subtype of the disease. In HER2-positive patients with a residual tumor burden, an escalation of post-neoadjuvant therapy leads to the improvement of survival, while (post)-neoadjuvant treatment de-escalation is currently being discussed in low-risk settings in order to avoid unnecessary toxicities.

Abstract

Patients with high-risk non-metastatic breast cancer are recommended for chemotherapy, preferably in the neoadjuvant setting. Beyond advantages such as a better operability and an improved assessment of individual prognosis, the preoperative administration of systemic treatment offers the unique possibility of selecting postoperative therapies according to tumor response. In patients with HER2-positive disease, both the escalation of therapy in the case of high-risk features and the de-escalation in patients with a low tumor load are currently discussed. Patients with small node-negative tumors receive primary surgery and, upon confirmation of pathological T1 N0 status, de-escalated adjuvant therapy with paclitaxel and trastuzumab. For those with a large tumor and/or nodal involvement, neoadjuvant polychemotherapy with a dual antibody blockade is recommended. Patients with invasive residual disease benefit from switching postoperative therapy to the antibody-drug-conjugate trastuzumab emtansine (T-DM1). In this review, we discuss current evidence and controversies regarding post-neoadjuvant treatment strategies in HER2-positive breast cancer.

Update Breast Cancer 2022 Part 1 – Early Stage Breast Cancer

Evidence relating to the treatment of breast cancer patients with early-stage disease has increased significantly in the past year. Abemaciclib, olaparib, and pembrolizumab are new drugs with good efficacy in the relevant patient groups. However, some questions remain unanswered. In particular, it remains unclear which premenopausal patients with hormone receptor-positive breast cancer should be spared unnecessary treatment. The question of the degree to which chemotherapy exerts a direct cytotoxic effect on the tumor or reduces ovarian function through chemotherapy could be of key importance. This group of patients could potentially be spared chemotherapy. New, previously experimental biomarker analysis methods, such as spatial analysis of gene expression (spatial transcriptomics) are gradually finding their way into large randomized phase III trials, such as the NeoTRIP trial. This in turn leads to a better understanding of the predictive factors of new therapies, for example immunotherapy. This review summarizes the scientific innovations from recent congresses such as the San Antonio Breast Cancer Symposium 2021 but also from recent publications.

Practice-Changing Perspectives regarding Systemic Therapy in Early Breast Cancer: Opinions of German Experts regarding the 17th St. Gallen International Consensus Conference

The general topic of this year's 17th St. Gallen (SG) International Consensus Conference on the treatment of patients with early breast cancer (SG-BCC) was "Customizing local and systemic therapies for women with early breast cancer." This topic considers that each treatment decision must also consider the cancer-specific situation of the individual patient. This year, the votes of the SG-BCC were again discussed taking into account the multidisciplinary German S3 Guidelines and the recommendations of the Breast Cancer Working Group of the AGO (Arbeitsgemeinschaft Gynäkologische Onkologie; AGO Mamma). As the international panel of the SG-BCC consists of experts from different countries, the votes do represent an international cross-section of opinions. Therefore, it is useful to discuss the voting results with respect to the German evidence-based treatment guidelines. This publication focuses mainly on systemic treatment.

The heparan sulphate proteoglycan Syndecan-1 (CD138) regulates tumour progression in a 3D model of ductal carcinoma in situ of the breast

Ductal carcinoma in situ (DCIS) is a form of breast cancer that is restricted to the lactiferous ducts and has not yet invaded the surrounding breast tissue. Dysregulation of the transmembrane heparan sulphate proteoglycan Syndecan-1 (Sdc-1) plays a role in tumour progression of invasive breast cancer (IBC). In DCIS, Sdc-1, c-Met and E-cadherin are part of a proangiogenic expression signature. In this study, we employed a siRNA knockdown approach in the DCIS model cell line MCF10A DCIS.com to investigate a potential connection between Sdc-1 and epithelial mesenchymal transition (EMT), proteolysis and the Rho kinase pathway. Analysis of gene expression data of the TNMplot.com database revealed that Sdc-1 expression was higher in primary breast tumours compared to metastases. The impact of Sdc-1-depletion on the cellular phenotype was investigated in a Matrigel-based three-dimensional cell culture model. Sdc-1 depletion resulted in the formation of larger spheroids and the formation of invasive protrusions. Application of matrix metalloproteinase (MMP) and Rho kinase inhibitors could block the Sdc-1-induced phenotype. qPCR analysis of Sdc-1-depleted cells in two-dimensional culture revealed upregulated expression of the EMT-markers CDH1, FN-1, CLDN1, the proteolysis markers MMP3, and MMP9, and HPSE, while MMP2, VIM and ROCK-2 were downregulated. Immunocytochemistry confirmed upregulation of MMP9 and fibronectin, the latter being particular prominent after ROCK inhibition. STRING analysis confirmed an interaction of the investigated gene products at the protein level. Our results suggest that diminished Sdc-1 expression plays a role in DCIS progression to IBC through deregulation of proteolytic factors and a partial EMT.

Pyrotinib-Containing Neoadjuvant Therapy in Patients With HER2-Positive Breast Cancer: A Multicenter Retrospective Analysis

Background

Pyrotinib, a small-molecule tyrosine kinase inhibitor, has been investigated as a component of neoadjuvant therapy in phase 2 trials of human epidermal growth factor receptor 2 (HER2)-positive breast cancer. This study aimed to evaluate the effectiveness and safety of pyrotinib-containing neoadjuvant therapy for patients with HER2-positive early or locally advanced breast cancer in the real-world setting.

Methods

Data of 97 patients with HER2-positive breast cancer from 21 centers across China treated with pyrotinib-containing neoadjuvant therapy were reviewed. Neoadjuvant therapy consisted of taxane/carboplatin/trastuzumab plus pyrotinib (TCbH+Py, 30 [30.9%]), anthracycline/cyclophosphamide followed by taxane/trastuzumab plus pyrotinib (AC-TH+Py) or taxane followed by anthracycline/cyclophosphamide/trastuzumab plus pyrotinib (T-ACH+Py, 29 [29.9%]), taxane/trastuzumab plus pyrotinib (TH+Py, 23 [23.7%]), and other pyrotinib-containing neoadjuvant treatment (15 [15.5%]). The primary outcome was breast pathological complete response (bpCR, ypT0/is) rate. Secondary outcomes included total pathological complete response (tpCR, ypT0/is ypN0) rate, objective response rate (ORR), and the incidence of preoperative adverse events.

Results

The ORR of pyrotinib-containing neoadjuvant therapy was 87.6% (85/97). The bpCR and tpCR rates were 54.6% (95% confidence interval [CI], 44.2%-64.7%) and 48.5% [95% CI, 38.2%-58.8%], respectively. The most common grade 3 or 4 treatment-related adverse events included diarrhea (15 [15.5%]), decreased hemoglobin (nine [9.3%]), and decreased neutrophil count (eight [8.2%]). No treatment-related deaths occurred.

Conclusion

Pyrotinib-containing neoadjuvant therapy for patients with HER2-positive early or locally advanced breast cancer shows favorable effectiveness with manageable toxicity in the real-world setting. Trastuzumab plus pyrotinib may be a novel option of dual HER2-targeted blockade.

Synthesis and Evaluation of Radioiodine-Labeled pH (Low) Insertion Peptide Variant 7-Like Peptide as a Noninvasive Tumor Microenvironment Imaging Agent in a Mouse MDA-MB-231 Triple-Negative Breast Cancer Model

PURPOSE

The pH (low) insertion peptide (pHLIP) family can target the tumor microenvironment (TME). If pHLIP can be labeled with radioiodine, the imaging and treatment of tumors can be considered. However, tyrosine and tryptophan can bind with iodine in the insertion region of pHLIP, and radioiodine labeling may affect the formation of α-helix structures in acidic environments; therefore, it is necessary to adjust the structure of pHLIP. This study aims to develop an ¹²⁵I-labeled pH (low) insertion peptide variant 7-like peptide (pHLIP (Var7) LP) for imaging the TME in MDA-MB-231 triple-negative breast cancer (TNBC) xenograft tumor models.

PROCEDURES

Based on pHLIP (Var7), a new peptide sequence, pHLIP (Var7) LP, was obtained by the sequence modification method and then characterized. The binding of pHLIP (Var7) LP to MDA-MB-231 cells was analyzed. pHLIP (Var7) LP was labeled with ¹²⁵I by the iodogen iodination method. Serial biodistribution studies and small-animal single photon emission computed tomography (SPECT)/computed tomography (CT) imaging in subcutaneous MDA-MB-231 TNBC-bearing mice were performed using [¹²⁵I] I-pHLIP (Var7) LP.

RESULTS

A novel peptide, pHLIP (Var7) LP, has the characteristics of an α-helix structure, electronegativity, and amphiphilicity. Circular dichroism (CD) spectroscopy showed that the peptide presented a typical pH-dependent transition from an unstructured conformation to an α-helix structure when the pH was reduced from 8.0 to 4.0. The relative fluorescence intensities of 5-carboxytetramethylrhodamine (5-TAMRA)-pHLIP(var7) LP at pH = 6.0, 6.6, and 7.4 were 100.00 ± 5.98%, 72.10 ± 4.65%, and 13.72 ± 1.41%, respectively. The distribution of [¹²⁵I] I-pHLIP (Var7) LP in tumors reached the highest level (8.7 ± 1.6% ID/g) at 2 h after injection, and the tumor-to-muscle ratios and tumor-to-blood ratios increased with time. Of the measured off-target organs, the stomach, kidney, and bladder showed higher uptake levels. SPECT imaging revealed rapid and sustained tumor uptake of [¹²⁵I] I-pHLIP (Var7) LP in breast cancer-bearing mice.

CONCLUSIONS

This study showed that [¹²⁵I]I-pHLIP (Var7)LP had rapid and sustained tumor uptake in MDA-MB-231 TNBC and provided a new method for TNBC imaging and further treatment.

PIK3CA-mutations in breast cancer

PURPOSE

Phosphatidylinositide-3-kinase (PI3K) regulates proliferation and apoptosis; somatic PIK3CA-mutations may activate these processes. Aim of this study was to determine the prevalence of PIK3CA-mutations in a cohort of early stage breast cancer patients and the association to the course of disease.

PATIENTS AND METHODS

From an unselected cohort of 1270 breast cancer patients (PiA, Prognostic Assessment in routine application, NCT01592825) 1123 tumours were tested for the three PIK3CA hotspot-mutations H1047R, E545K, and E542K by qPCR. Primary objectives were the prevalence of somatic PIK3CA-mutations and their association to tumour characteristics. Secondary objective was the association of PIK3CA-mutations to recurrence-free interval (RFI) and overall survival.

RESULTS

PIK3CA-mutation rate was 26.7% (300 of 1123). PIK3CA-mutations were significantly more frequent in steroid hormone-receptor (SHR)-positive HER2-negative (31.4%), and G1 and G2 tumours (32.8%). Overall, we did not observe a significant association of PIK3CA-mutations to RFI. In SHR-positive BCs with PIK3CA-mutations, a strong trend for impaired  RFI was observed (adjusted HR 1.64, 95% CI 0.958-2.807), whilst in SHR-negative BCs PIK3CA-mutations were insignificantly associated with improved RFI (adjusted HR 0.49; 95% CI 0.152-1.597). Of note, we observed a significantly detrimental prognostic impact of PIK3CA-mutations on RFI in SHR-positive, HER2-negative BCs if only aromatase inhibitors were administered as adjuvant therapy (adjusted HR 4.44, 95% CI 1.385-13.920), whilst no impact was observed in tamoxifen treated patients.

CONCLUSION

This cohort study speficies the overall mutation rate of PIK3CA in early breast cancer. The impact of PIK3CA-mutations on RFI and OS was heterogeneous. Our results suggest that estrogen deprivation failes to be active in case of PIK3CA-mutation.

Expert Discussion: Hypofractionated Radiation Therapy - Standard for All Indications?

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Integrating CDK4/6 inhibitors in the treatment of patients with early breast cancer

CDK4/6 inhibitors have an established role in the treatment of hormone receptor positive HER2-negative advanced breast cancer. All studies conducted in metastatic breast cancer showed a benefit in delaying progression when added to standard endocrine therapy, regardless of therapy line, pretreatment, menopausal status, site of metastasis, CDK4/6 inhibitor used and associated endocrine therapy. A benefit in overall survival has also been demonstrated. In early breast cancer, only the MonarchE study has shown an improved invasive disease-free survival with abemaciclib taken for 2 years, whereas the Penelope-B did not meet the primary endpoint and the PALLAS study was terminated early for futility. Studies conducted in the neoadjuvant setting might help to explain the discordant results.

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CDK4/6 inhibitors increase PFS in advanced breast cancer in all subgroups.

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2-years abemaciclib added to endocrine therapy improves invasive disease-free survival in high-risk breast cancer.

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Palbociclib did not improve invasive disease-free survival in early breast cancer.

Endocrine Treatment for Breast Cancer Patients Revisited-History, Standard of Care, and Possibilities of Improvement

PURPOSE OF REVIEW

Due to the findings of current studies and the approval of novel substances for the therapy of hormone-receptor-positive breast cancer patients, the established standards of endocrine treatment are changing. The purpose of this review is to give an overview of the history of endocrine treatment, to clarify its role in the present standard of care, and to discuss the possibilities of improvement.

RECENT FINDINGS

Tamoxifen, aromatase inhibitors, and fulvestrant are the main drugs that have been used for decades in the therapy of hormone-receptor-positive breast cancer patients. However, since a relevant number of women suffer at some point from disease recurrence or progression, several novel substances are being investigated to overcome resistance mechanisms by interfering with certain signaling pathways, such as the PI3K/AKT/mTOR or the CDK4/6 pathways. mTOR and CDK4/6 inhibitors were the first drugs approved for this purpose and many more are in development.

SUMMARY

Endocrine treatment is one of the best tolerable cancer therapies available. Continuous investigation serves to improve patients' outcomes and modernize the current standard of care. Considering the resistance mechanisms and substances analyzed against these, endocrine treatment of hormone-receptor-positive breast cancer is on the brink of a new era.

AGO Algorithms for the Treatment of Breast Cancer: Update 2021

Therapy options shown in the algorithms are based on the current AGO recommendations, but cannot represent all evidence-based treatment options, since prior therapies, performance status, comorbidities, patient preference, etc. must be taken into account for the actual treatment choice. In individual cases, other evidence-based treatment options may also be appropriate and justified. Regardless of approval status, the algorithms only take into account drugs that were available in Germany at the time the algorithm was last updated. Here we present the 2021 update of AGO treatment algorithms for early and metastatic breast cancer, which are intended to intensify structured treatment decision by providing reproducible and evidence-based treatment paths and may be helpful for a broad treatment landscape.

AGO Recommendations for the Surgical Therapy of the Axilla After Neoadjuvant Chemotherapy: 2021 Update

For many decades, the standard procedure to treat breast cancer included complete dissection of the axillary lymph nodes. The aim was to determine histological node status, which was then used as the basis for adjuvant therapy, and to ensure locoregional tumour control. In addition to the debate on how to optimise the therapeutic strategies of systemic treatment and radiotherapy, the current discussion focuses on improving surgical procedures to treat breast cancer. As neoadjuvant chemotherapy is becoming increasingly important, the surgical procedures used to treat breast cancer, whether they are breast surgery or axillary dissection, are changing. Based on the currently available data, carrying out SLNE prior to neoadjuvant chemotherapy is not recommended. In contrast, surgical axillary management after neoadjuvant chemotherapy is considered the procedure of choice for axillary staging and can range from SLNE to TAD and ALND. To reduce the rate of false negatives during surgical staging of the axilla in pN+ _CNB stage before NACT and ycN0 after NACT, targeted axillary dissection (TAD), the removal of > 2 SLNs (SLNE, no untargeted axillary sampling), immunohistochemistry to detect isolated tumour cells and micro-metastases, and marking positive lymph nodes before NACT should be the standard approach. This most recent update on surgical axillary management describes the significance of isolated tumour cells and micro-metastasis after neoadjuvant chemotherapy and the clinical consequences of low volume residual disease diagnosed using SLNE and TAD and provides an overview of this yearʼs AGO recommendations for surgical management of the axilla during primary surgery and in relation to neoadjuvant chemotherapy.