HER2-Positive Early Breast Cancer: Time for Ultimate De-Escalation?

De-escalation is currently taking place in both the surgical and systemic treatment of breast cancer. The introduction of trastuzumab, the first monoclonal antibody against the HER2 receptor, over 20 years ago was a milestone in the treatment of HER2-positive breast cancer and marked the beginning of a new era in targeted tumor therapy. In the sense of de-escalation, omitting non-targeted cytotoxic chemotherapy altogether is often hailed as the ultimate goal of oncological research. Especially in cases of small, node-negative, HER2-positive early breast cancer, it remains a challenge for clinicians to establish the safest and most efficient treatment plan while considering the significant potential for toxic side effects associated with chemotherapy and HER2-targeted therapy, and the generally excellent prognosis. In this context, several ongoing studies are currently assessing chemotherapy-free regimens as part of strategies aimed at de-escalating therapy in the field of HER2-positive early breast cancer. Despite the promising early results of these studies, the combination of anti-HER2 treatment with a chemotherapy backbone remains the standard of care.

Efficacy of Lapatinib in Patients with HER2-Negative Metastatic Breast Cancer and HER2-Positive Circulating Tumor Cells-The DETECT III Clinical Trial.

BACKGROUND: The phenotypes of tumor cells change during disease progression, but invasive rebiopsies of metastatic lesions are not always feasible. Here we aimed to determine whether initially HER2-negative metastatic breast cancer (MBC) patients with HER2-positive circulating tumor cells (CTCs) benefit from a HER2-targeted therapy. METHODS: The open-label, interventional randomized phase III clinical trial (EudraCT Number 2010-024238-46, CliniclTrials.gov Identifier: NCT01619111) recruited from March 2012 until September 2019 with a follow-up duration of 19.5 months. It was a multicenter clinical trial with 94 participating German study centers. A total of 2137 patients with HER2-negative MBC were screened for HER2-positive CTCs with a final modified intention-to-treat population of 101 patients. Eligible patients were randomized to standard therapy with or without lapatinib. Primary study endpoints included CTC clearance (no CTCs at the end of treatment) and secondary endpoints were progression-free survival, overall survival (OS), and safety. RESULTS: In both treatment arms CTC clearance at first follow-up visit-although not being significantly different for both arms at any time point-was significantly associated with improved OS (42.4 vs 14.1 months; P = 0.002). Patients treated additionally with lapatinib had a significantly improved OS over patients receiving standard treatment (20.5 vs 9.1 months, P = 0.009). CONCLUSIONS: DETECT III is the first clinical study indicating that phenotyping of CTCs might have clinical utility for stratification of MBC cancer patients to HER2-targeting therapies. The OS benefit could be related to lapatinib, but further studies are required to prove this clinical observation. ClinicalTrials.gov Registration Number: NCT01619111.

Latissimus dorsi flap for breast reconstruction: a large single-institution evaluation of surgical outcome and complications.

PURPOSE: The use of autologous tissues is considered gold standard for patients undergoing breast reconstruction and is the preferred method in the post-radiation setting. Although the latissimus dorsi flap (LDF) has been replaced by abdominal flaps as technique of choice, it remains a valuable option in several specific clinical situations and its use has been regaining popularity in recent years. In this work, we present an 18-year retrospective analysis of a single-institution single-surgeon experience with LDF-based reconstruction with focus on early complications and reconstructive failures. METHODS: Hospital records of all patients undergoing breast surgery for any reason in the Certified Breast Cancer Center, Regio Klinikum Pinneberg, Germany between April, 1st 2005 and October, 31st 2022 were reviewed. 142 consecutive LDF-based reconstructive procedures were identified. Detailed information was gathered on patient characteristics, treatment-related factors, and complications. RESULTS: One hundred forty patients (139 female, 1 male) received 142 LDF-based surgeries. The flap was used mainly for immediate breast reconstruction with or without implant (83% of patients), followed by defect coverage after removal of a large tumor (7%), implant-to-flap conversion with or without placement of a new implant (6%), and delayed post-mastectomy reconstruction (4%). The use of LDF decreased between 2005 and 2020 (2005: 17, 2006: 13, 2007: 14, 2008: 16, 2009: 5, 2010: 9, 2011: 8, 2012: 3, 2013: 10, 2014: 8, 2015: 8, 2016: 7, 2017: 7, 2018: 4, 2019: 4, 2020: 2, 2021: 6, 2022: 4). Surgery was performed for invasive breast cancer in 78%, ductal carcinoma in situ in 20% and other reasons such as genetic mutation in 1% of patients. Ipsilateral radiation therapy was received by 12% of patients prior to LDF surgery and by 37% after the surgery. 25% of patients were smokers. The median duration of surgery, including all procedures conducted simultaneously such as e.g., mastectomy, axillary surgery, or implant placement, was 117 min (range 56-205). Patients stayed in the hospital for a median of 7 days (range 2-23 days). The most common complication was seroma (26%), followed by wound dehiscence (8%), surgical site infection (7%), partial skin and/or nipple necrosis of any size (7%) and hematoma requiring surgical evacuation (2%). 19% of all patients required seroma aspiration or drainage, mostly at the donor site and performed under ultrasound guidance in the ambulatory setting. Flap loss due to necrosis occurred in 2% of patients. CONCLUSIONS: Latissimus dorsi flap is a well-established surgical technique commonly used for immediate breast reconstruction as well as defect coverage in locally advanced breast cancer. To the best of our knowledge, this is one of the largest single-surgeon analyses of early complications in patients receiving LDF. As expected, seroma was the most common complication observed in nearly one third of patients and requiring a therapeutic intervention in every fifth patient. Serious adverse events occurred rarely, and flap loss rate was very low.

Determination of the androgen receptor status of disseminated tumor cells in primary breast cancer patients.

PURPOSE: Androgen receptor (AR) can serve as a new therapeutic target since it was shown to play a proliferative role in several breast cancer (BC) subtypes. Moreover, AR positivity has been suggested to reflect the metastatic potential of tumor cells in some BC subtypes. The aim of this study was to determine the AR expression on disseminated tumor cells (DTCs) as a surrogate marker of minimal residual disease (MRD) and potential precursor of metastasis in early BC. METHODS: Bone marrow (BM) aspirates from 62 DTC-positive early BC patients were included into this study and analyzed by immunofluorescence staining for the presence of AR-positive DTCs. CK-positive, CD45-negative cells containing an intact nucleus (DAPI positive) were identified as DTCs. AR expression of the primary tumor (PT) was assessed by immunohistochemistry on formalin-fixed, paraffin-embedded (FFPE) tumor sections from core biopsies and surgical specimens. RESULTS: AR status of DTCs could be determined in 21 patients. We detected AR-positive DTCs in nine samples (43%). AR expression of DTCs and corresponding PT showed a concordance rate of 33%. The DTC-AR status did not correlate with clinicopathological factors, nor did we observe a significant correlation between the AR status of the PT and other established prognostic factors for BC. CONCLUSION: AR-positive DTCs can be detected in BM of early BC patients with a marked discordance of the AR status between DTCs and corresponding PTs. The clinical significance of these findings needs further investigation.

Locoregional Therapy: From Mastectomy to Reconstruction, Targeted Surgery, and Ultra-Hypofractionated Radiotherapy.

Background: The past 3 decades have seen an unprecedented shift toward treatment de-escalation in surgical therapy of breast cancer. Summary: Radical mastectomy has been replaced by breast-conserving and oncoplastic approaches in most patients, and full axillary lymph node dissection by less radical staging procedures, such as sentinel lymph node biopsy and targeted axillary dissection. Further, attempts have been made to spare healthy tissue while increasing the probability of removing the tumor with clear margins, thus improving cosmetic results and minimizing the risk of local recurrence. In this context, modern probe-guided localization techniques have been introduced to guide surgical excision. This progress was accompanied by the development of targeted systemic therapies. At the same time, radiotherapy for breast cancer has undergone significant changes. The use of hypofractionation has decreased the typical length of a treatment course from 5-6 weeks to 1-3 weeks. Partial breast irradiation is now a valid option for de-escalation in patients with low-risk features. Axillary radiotherapy achieves similar recurrence rates and decreases the risk of lymphedema in patients with limited sentinel node involvement. Key Messages: Taken together, these advances are important steps toward individualization of locoregional management strategies. This highlights the importance of interdisciplinary approaches for de-escalation of locoregional therapies.

Whole Exome Analysis to Select Targeted Therapies for Patients with Metastatic Breast Cancer - A Feasibility Study.

Introduction: The purpose of this feasibility study was to select targeted therapies according to "ESMO Scale for Clinical Actionability of molecular Targets (ESCAT)". Data interpretation was further supported by a browser-based Treatment Decision Support platform (MH Guide, Molecular Health, Heidelberg, Germany). Patients: We applied next generation sequencing based whole exome sequencing of tumor tissue and peripheral blood of patients with metastatic breast cancer (n = 44) to detect somatic as well as germline mutations. Results: In 32 metastatic breast cancer patients, data interpretation was feasible. We identified 25 genomic alterations with ESCAT Level of Evidence I or II in 18/32 metastatic breast cancer patients, which were available for evaluation: three copy number gains in HER2 , two g BRCA1 , two g BRCA2 , six PIK3CA, one ESR1 , three PTEN , one AKT1 and two HER2 mutations. In addition, five samples displayed Microsatellite instability high-H. Conclusions: Resulting treatment options were discussed in a tumor board and could be recommended in a small but relevant proportion of patients with metastatic breast cancer (7/18). Thus, this study is a valuable preliminary work for the establishment of a molecular tumor board within the German initiative "Center for Personalized Medicine" which aims to shorten time for analyses and optimize selection of targeted therapies.

Is the (Neo)adjuvant Therapy of Patients with Primary HER2-positive Breast Cancer Cost-Covering?: Process Cost Analysis of Neoadjuvant and Post-Neoadjuvant Systemic Therapy of Patients with Primary HER2-positive Breast Cancer.

Introduction HER2 positivity is one of the most important predictive factors in the treatment of breast cancer patients. Thanks to new targeted anti-HER2 drugs, the prognosis for HER2-positive breast cancer patients has been significantly improved, and the treatment can now be designed according to the risk situation and the response to treatment. At the same time, these innovative targeted anti-HER2 drugs are associated with high costs and require long and involved patient care. Materials and Methods In this paper, we compare the treatment costs of three post-neoadjuvant treatment regimens (trastuzumab vs. trastuzumab/pertuzumab vs. T-DM1) in early stage HER2-positive breast cancer from the perspective of the oncological outpatient clinic of a certified breast center at a university hospital, and evaluate the cost coverage. Results The highest costs in systemic therapy were the material costs. These were the highest for dual blockade with trastuzumab/pertuzumab, followed by T-DM1 and trastuzumab monotherapy. According to our study, all three of these post-neoadjuvant therapy variants achieve a positive contribution margin. While all three models have similar contribution margins, the treatment pathway with T-DM1 is associated with a 30% lower contribution margin. Conclusions Although these model calculations are associated with limitations in view of the introduction of biosimilar antibodies, it can be shown that modern therapeutic approaches do not always have to be associated with lower profits.

Localization Techniques for Non-Palpable Breast Lesions: Current Status, Knowledge Gaps, and Rationale for the MELODY Study (EUBREAST-4/iBRA-NET, NCT 05559411).

BACKGROUND: Surgical excision of a non-palpable breast lesion requires a localization step. Among available techniques, wire-guided localization (WGL) is most commonly used. Other techniques (radioactive, magnetic, radar or radiofrequency-based, and intraoperative ultrasound) have been developed in the last two decades with the aim of improving outcomes and logistics. METHODS: We performed a systematic review on localization techniques for non-palpable breast cancer. RESULTS: For most techniques, oncological outcomes such as lesion identification and clear margin rate seem either comparable with or better than for WGL, but evidence is limited to small cohort studies for some of the devices. Intraoperative ultrasound is associated with significantly higher negative margin rates in meta-analyses of randomized clinical trials (RCTs). Radioactive techniques were studied in several RCTs and are non-inferior to WGL. Smaller studies show higher patient preference towards wire-free localization, but little is known about surgeons' and radiologists' attitudes towards these techniques. CONCLUSIONS: Large studies with an additional focus on patient, surgeon, and radiologist preference are necessary. This review aims to present the rationale for the MELODY (NCT05559411) study and to enable standardization of outcome measures for future studies.

Comparative analysis of EpCAM high-expressing and low-expressing circulating tumour cells with regard to their clonal relationship and clinical value.

BACKGROUND: Circulating tumour cells (CTCs) are mainly enriched based on the epithelial cell adhesion molecule (EpCAM). Although it was shown that an EpCAM low-expressing CTC fraction is not captured by such approaches, knowledge about its prognostic and predictive relevance and its relation to EpCAM-positive CTCs is lacking. METHODS: We developed an immunomagnetic assay to enrich CTCs from metastatic breast cancer patients EpCAM independently using antibodies against Trop-2 and CD-49f and characterised their EpCAM expression. DNA of single EpCAM high expressing and low expressing CTCs was analyzed regarding chromosomal aberrations and predictive mutations. Additionally, we compared CTC-enrichment on the CellSearch system using this antibody mix and the EpCAM based enrichment. RESULTS: Both antibodies acted synergistically in capturing CTCs. Patients with EpCAM high-expressing CTCs had a worse overall and progression-free survival. EpCAM high- and low-expressing CTCs presented similar chromosomal aberrations and mutations indicating a close evolutionary relationship. A sequential enrichment of CTCs from the EpCAM-depleted fraction yielded a population of CTCs not captured EpCAM dependently but harbouring predictive information. CONCLUSIONS: Our data indicate that EpCAM low-expressing CTCs could be used as a valuable tumour surrogate material-although they may be prognostically less relevant than EpCAM high-expressing CTCs-and have particular benefit if no CTCs are detected using EpCAM-dependent technologies.

Current trends in diagnostic and therapeutic management of the axilla in breast cancer patients receiving neoadjuvant therapy: results of the German-wide NOGGO MONITOR 24 survey.

PURPOSE: In the last 2 decades, the optimal management of the axilla in breast cancer patients receiving neoadjuvant chemotherapy (NACT) has been one of the most frequently discussed topics. Little is known about the attitudes of surgeons/radiologists towards new developments such as targeted axillary dissection. Therefore, the NOGGO conducted a survey to evaluate the current approach to axillary management. METHODS: A standardized digital questionnaire was sent out to > 200 departments in Germany between 7/2021 and 5/2022. The survey was supported by EUBREAST. RESULTS: In total, 116 physicians completed the survey. In cN0 patients scheduled to receive NACT, 89% of respondents recommended sentinel lymph node biopsy (SLNB) after NACT. In case of ypN1mi(sn), 44% advised no further therapy, while 31% proposed ALND and 25% axillary irradiation. 64% of respondents recommended a minimally invasive axillary biopsy to cN + patients. TAD was used at the departments of 82% of respondents and was offered to all cN + patients converting to ycN0 by 57% and only to selected patients, usually based on the number of suspicious nodes at time of presentation, by 43%. The most common marking technique was a clip/coil. 67% estimated that the detection rate of their marker was very good or good. CONCLUSION: This survey shows a heterogenous approach towards axillary management in the neoadjuvant setting in Germany. Most respondents follow current guidelines. Since only two-thirds of respondents experienced the detection rate of the marker used at their department as (very) good, future studies should focus on the comparative evaluation of different marking techniques.

New treatment strategies for human epidermal growth factor receptor 2-positive breast cancer in 2023.

PURPOSE OF REVIEW: Taxanes in combination with trastuzumab and pertuzumab are the established first-line standard in the treatment of human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer. In the last years, several new HER2-targeted therapies, including antibody-drug conjugates (ADCs) and tyrosine kinase inhibitors, have been approved for therapy after trastuzumab or dual blockade. In this review, the current treatment algorithms are discussed, including these new treatment options. RECENT FINDINGS: The ADC T-DM1 was the established second-line standard based on the results of the EMILIA trial. Recently, the DESTINY-Breast03 trial compared T-DM1 with the new ADC trastuzumab deruxtecan (T-DXd) in patients with disease progression after treatment with taxanes and trastuzumab. T-DXd was associated with an improved progression-free survival and a trend toward improved overall survival, establishing T-DXd as a new second-line standard. The HER2CLIMB trial demonstrated a significant progression-free survival and overall survival benefit for the tyrosine kinase inhibitor tucatinib in combination with trastuzumab and capecitabine after T-DM1 and trastuzumab/pertuzumab. This benefit was also observed in patients with active brain metastases defining this combination as the preferred second or third-line option in these patients. SUMMARY: New treatment strategies in HER2-positive metastatic breast cancer have substantially improved the clinical outcome of these patients, including those with active brain metastases.

Evaluation of Intraoperative Frozen Section Analysis with Final Histopathology Results for Sentinel Lymph Node Biopsy: Z0011 Criteria Eligible Versus Ineligible Breast Cancer Patients.

Background Intraoperative frozen section analysis (FSA) of sentinel lymph nodes (SLNs) declined in the post American College of Surgeons Oncology Group Z0011 (ACOSOG Z0011) trial era. However, for those patients who do not meet the ACOSOG Z0011 criteria, FSA continues to be a valuable tool in intraoperative decision-making for axillary lymph node dissection (ALND). The aim of this study was therefore to retrospectively evaluate the benefit and accuracy of FSA of Z0011 criteria eligible versus ineligible patients and identify possible predictive factors for false negative results. Methods Intraoperative FSA was performed on SLNs of 522 cT1-T3 breast cancer patients between 2008 and 2013. Clinicopathologic characteristics were retrospectively assessed by chart review. Results Overall FSA sensitivity and specificity was 67.8% and 100%. Sensitivity was generally higher for macrometastasis than for micrometastasis. The Z0011 eligible group showed a sensitivity and specificity of 72.7% and 100% versus 62.1% and 100% in the Z0011 ineligible group. Importantly, subgroup analysis of ≤ 2 versus > 2 positive SLNs of the Z0011 eligible group demonstrated both a 100% specificity and sensitivity. Several clinicopathologic factors were associated with a higher rate of false negative results in the Z0011 ineligible patient group. FSA was beneficial for 22.2% of Z0011 ineligible patients and for only 0.6% of Z0011 eligible patients regarding intraoperative decision-making for ALND. Conclusions FSA continues to be especially beneficial in the intraoperative assessment of SLNs in the Z0011 ineligible group to prevent second stage ALND. Despite an overall lower FSA sensitivity in the Z0011 eligible patient group, FSA offers in both groups a comparable high sensitivity and diagnostic accuracy for macrometastasis.

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

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.

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.

Malignancy Rate and Malignancy Risk Assessment in Different Lesions of Uncertain Malignant Potential in the Breast (B3 Lesions): An Analysis of 192 Cases from a Single Institution.

Background: The question of how to deal with B3 lesions is of emerging interest. Methods: In the breast diagnostics of 192 patients between 2009 and 2016, a minimally invasive biopsy revealed a B3 lesion with subsequent resection. This study investigates the malignancy rate of different B3 subgroups and the risk factors that play a role in obtaining a malignant finding. Results: The distribution of B3 lesions after minimally invasive biopsy was as follows: atypical ductal hyperplasia (ADH), 7.3%; flat epithelial atypia (FEA), 7.8%; lobular neoplasia (LN), 7.8%; papilloma (Pa), 49.5%; phylloidal tumour (PT), 8.9%; radial sclerosing scar (RS), 3.1%; mixed findings, 10.4%; and other B3 lesions, 5.2%. Most B3 lesions were detected by stereotactic vacuum-assisted biopsy (44.3%), 36.5% by ultrasound-assisted biopsy, and 19.3% by magnetic resonance imaging-assisted biopsy. Most B3 lesions (55.2%) were verified by surgical resection, whereas 30.7% were downgraded to a benign lesion. About 14.1% of the cases were upgraded to malignant lesions, 9.4% to ductal carcinoma in situ and 4.7% to invasive carcinoma. In relation to individual B3 lesions, the following malignancy rates were found: 28.6% (ADH), 13.3% (FEA), 33.3% (LN), 12.6% (Pa), 5.9% (PT), and 0% (RS). The most important risk factor was increasing age. Postmenopausal status was considered an increased risk for an upgrade (p = 0.015). A known malignancy in the ipsilateral breast was a significant risk factor for a malignant upgrade (p = 0.003). Conclusion: Increasing knowledge about B3 lesions allows us to develop a "lesion-specific" therapy approach in the heterogeneous group of B3 lesions, with follow-up imaging for some lesions with less malignant potential and concordance with imaging or further surgical resection in cases of disconcordance with imaging or higher malignant potential.

Invasive Breast Carcinoma with Neuroendocrine Differentiation: A Single-Center Analysis of Clinical Features and Prognosis.

Introduction Invasive breast cancer with neuroendocrine differentiation is a rare subtype of breast malignancy. Due to frequent changes in the definition of these lesions, the correct diagnosis, estimation of exact prevalence, and clinical behaviour of this entity may be challenging. The aim of this study was to evaluate the prevalence, clinical features, and outcomes in a large cohort of patients with breast cancer with neuroendocrine differentiation. Patients Twenty-seven cases of breast cancer with neuroendocrine differentiation have been included in this analysis. Twenty-one cases were identified by systematic immunohistochemical re-evaluation of 465 breast cancer specimens using the neuroendocrine markers chromogranin A and synaptophysin, resulting in a prevalence of 4.5%. A further six cases were identified by a review of clinical records. Results Median age at the time of diagnosis was 61 years. 70% of patients had T2 - 4 tumors and 37% were node-positive. The most common immunohistochemical subtype was HR-positive/HER2-negative (85%). 93% were positive for synaptophysin and 48% for chromogranin A. Somatostatin receptor type 2A status was positive in 12 of 24 analyzed tumors (50%). Neuroendocrine-specific treatment with somatostatin analogues was administered in two patients. The 5-year survival rate was 70%. Conclusions Breast cancer with neuroendocrine differentiation is mostly HR-positive/HER2-negative and the diagnosis is made at a higher TNM stage than in patients with conventional invasive breast carcinoma. Moreover, breast cancer with neuroendocrine differentiation was found to be associated with impaired prognosis in several retrospective trials. Due to somatostatin receptor 2A expression, somatostatin receptor-based imaging can be used and somatostatin receptor-targeted therapy can be offered in selected cases.

Liquid Biopsy in Metastatic Breast Cancer: Current Role of Circulating Tumor Cells and Circulating Tumor DNA.

BACKGROUND: In metastatic breast cancer (MBC), blood-based diagnostics have become a major focus of oncological research in the last 2 decades. Detection of circulating tumor cells (CTCs) and circulating tumor DNA (ctDNA) has the potential to improve prognosis assessment and complement standard therapy monitoring tools. SUMMARY: To date, several large analyses have confirmed high CTC counts as an independent prognostic factor. Persistently high CTC numbers during systemic treatment are associated with early progression, but it remains to be clarified which therapeutic options should be offered to such patients since the SWOG 0500 trial failed to show benefit from early switch to another chemotherapy regimen in patients with CTC persistence. In comparison, evidence on the prognostic value of ctDNA is still limited. Most importantly, liquid biopsy-guided treatment interventions have been investigated in several trials. In patients with hormone receptor-positive and HER2-negative MBC, CTC-driven therapy choices resulted in similar PFS to physician's choice treatment. Recently, the DETECT III trial has shown that patients with HER2-negative MBC and HER2-positive CTCs may benefit from targeted anti-HER2 treatment with lapatinib. ctDNA-driven therapy selection has already been approved in clinical routine: alpelisib is the first targeted treatment indicated on the basis of a ctDNA test. Key Messages: CTCs and ctDNA predict clinical outcome and have a potential to improve therapy choices in MBC.

Multiparametric Circulating Tumor Cell Analysis to Select Targeted Therapies for Breast Cancer Patients.

BACKGROUND: The analysis of liquid biopsies, e.g., circulating tumor cells (CTCs) is an appealing diagnostic concept for targeted therapy selection. In this proof-of-concept study, we aimed to perform multiparametric analyses of CTCs to select targeted therapies for metastatic breast cancer patients. METHODS: First, CTCs of five metastatic breast cancer patients were analyzed by whole exome sequencing (WES). Based on the results, one patient was selected and monitored by longitudinal and multiparametric liquid biopsy analyses over more than three years, including WES, RNA profiling, and in vitro drug testing of CTCs. RESULTS: Mutations addressable by targeted therapies were detected in all patients, including mutations that were not detected in biopsies of the primary tumor. For the index patient, the clonal evolution of the tumor cells was retraced and resistance mechanisms were identified. The AKT1 E17K mutation was uncovered as the driver of the metastatic process. Drug testing on the patient's CTCs confirmed the efficacy of drugs targeting the AKT1 pathway. During a targeted therapy chosen based on the CTC characterization and including the mTOR inhibitor everolimus, CTC numbers dropped by 97.3% and the disease remained stable as determined by computer tomography/magnetic resonance imaging. CONCLUSION: These results illustrate the strength of a multiparametric CTC analysis to choose and validate targeted therapies to optimize cancer treatment in the future. Furthermore, from a scientific point of view, such studies promote the understanding of the biology of CTCs during different treatment regimens.

DCIS in Male and Aged Women with Comorbidities.

The incidence rates of ductal carcinoma in situ (DCIS) have increased rapidly over the last two decades in all patient groups including older women and men. DCIS in aged women has an excellent prognosis and the risk of local recurrence is lower compared to younger patients. Since adjuvant radiation after lumpectomy and endocrine treatment do not significantly influence overall survival a de-escalation of treatment especially in case of grade 1 lesions in women with comorbidities can be considered. Pure DCIS in men is a very rare disease representing approximately 5% of all male breast cancers. The most common type of DCIS in men is a papillary carcinoma mostly of low or intermediate grade developing from large central ducts, since male breast typically lacks lobules and terminal duct-lobular units (TDLU). A male DCIS of high grade is rare and mostly associated with severe hyperestrogenism, e.g., in case of gynecomastia. The most common risk factors in men are increasing age, high estrogen levels and positive family history. DCIS in men is usually a clinically apparent disease. The most common symptoms described in the literature are palpable, often cystic mass, coexisting or isolated nipple discharge (mostly bloody, in rare cases watery) or nipple alteration. A standard treatment among men with DCIS is a simple mastectomy without radiation. The prognosis is excellent.

Disseminated tumour cells from the bone marrow of early breast cancer patients: Results from an international pooled analysis.

PURPOSE: Presence of disseminated tumour cells (DTCs) in the bone marrow (BM) has been described as a surrogate of residual disease in patients with early breast cancer (EBC). PADDY (Pooled Analysis of DTC Detection in Early Breast Cancer) is a large international analysis of pooled data that aimed to assess the prognostic impact of DTCs in patients with EBC. EXPERIMENTAL DESIGN: Individual patient data were collected from 11 centres. Patients with EBC and available follow-up data in whom BM sampling was performed at the time of primary diagnosis before receiving any anticancer treatment were eligible. DTCs were identified by antibody staining against epithelial cytokeratins. Multivariate Cox regression was used to compare the survival of DTC-positive versus DTC-negative patients. RESULTS: In total, 10,307 patients were included. Of these, 2814 (27.3%) were DTC-positive. DTC detection was associated with higher tumour grade, larger tumour size, nodal positivity, oestrogen receptor and progesterone receptor negativity, and HER2 positivity (all p < 0.001). Multivariate analyses showed that DTC detection was an independent prognostic marker for overall survival, disease-free survival and distant disease-free survival with hazard ratios (HR) and 95% confidence intervals (CI) of 1.23 (95% CI: 1.06-1.43, p = 0.006), 1.30 (95% CI: 1.12-1.52, p < 0.001) and 1.30 (95% CI: 1.08-1.56, p = 0.006), respectively. There was no association between locoregional relapse-free survival and DTC detection (HR 1.21; 95% CI 0.68-2.16; p = 0.512). CONCLUSIONS: DTCs in the BM represent an independent prognostic marker in patients with EBC. The heterogeneous metastasis-initiating potential of DTCs is consistent with the concept of cancer dormancy.