Trends in use of neoadjuvant systemic therapy in patients with clinically node-positive breast cancer in Europe: prospective TAXIS study (OPBC-03, SAKK 23/16, IBCSG 57-18, ABCSG-53, GBG 101).

PURPOSE: The aim of this study was to evaluate clinical practice heterogeneity in use of neoadjuvant systemic therapy (NST) for patients with clinically node-positive breast cancer in Europe. METHODS: The study was preplanned in the international multicenter phase-III OPBC-03/TAXIS trial (ClinicalTrials.gov Identifier: NCT03513614) to include the first 500 randomized patients with confirmed nodal disease at the time of surgery. The TAXIS study's pragmatic design allowed both the neoadjuvant and adjuvant setting according to the preferences of the local investigators who were encouraged to register eligible patients consecutively. RESULTS: A total of 500 patients were included at 44 breast centers in six European countries from August 2018 to June 2022, 165 (33%) of whom underwent NST. Median age was 57 years (interquartile range [IQR], 48-69). Most patients were postmenopausal (68.4%) with grade 2 and 3 hormonal receptor-positive and human epidermal growth factor receptor 2-negative breast cancer with a median tumor size of 28 mm (IQR 20-40). The use of NST varied significantly across the countries (p < 0.001). Austria (55.2%) and Switzerland (35.8%) had the highest percentage of patients undergoing NST and Hungary (18.2%) the lowest. The administration of NST increased significantly over the years (OR 1.42; p < 0.001) and more than doubled from 20 to 46.7% between 2018 and 2022. CONCLUSION: Substantial heterogeneity in the use of NST with HR+/HER2-breast cancer exists in Europe. While stringent guidelines are available for its use in triple-negative and HER2+ breast cancer, there is a need for the development of and adherence to well-defined recommendations for HR+/HER2-breast cancer.

Use of sentinel lymph node biopsy in elderly patients with breast cancer - 10-year experience from a Swiss university hospital.

BACKGROUND: The Choosing Wisely initiative recommended the omission of routine sentinel lymph node biopsy (SLNB) in patients ≥ 70 years of age, with clinically node-negative, early stage, hormone receptor (HR) positive and human epidermal growth factor receptor 2 (Her2) negative breast cancer in August 2016. Here, we assess the adherence to this recommendation in a Swiss university hospital. METHODS: We conducted a retrospective single center cohort study from a prospectively maintained database. Patients ≥ 18 years of age with node-negative breast cancer were treated between 05/2011 and 03/2022. The primary outcome was the percentage of patients in the Choosing Wisely target group who underwent SLNB before and after the initiative went live. Statistical significance was tested using chi-squared test for categorical and Wilcoxon rank-sum tests for continuous variables. RESULTS: In total, 586 patients met the inclusion criteria with a median follow-up of 2.7 years. Of these, 163 were ≥ 70 years of age and 79 were eligible for treatment according to the Choosing Wisely recommendations. There was a trend toward a higher rate of SLNB (92.7% vs. 75.0%, p = 0.07) after the Choosing Wisely recommendations were published. In patients ≥ 70 years with invasive disease, fewer received adjuvant radiotherapy after omission of SLNB (6.2% vs. 64.0%, p < 0.001), without differences concerning adjuvant systemic therapy. Both short-term and long-term complication rates after SLNB were low, without differences between elderly patients and those < 70 years. CONCLUSIONS: Choosing Wisely recommendations did not result in a decreased use of SLNB in the elderly at a Swiss university hospital.

Association of relative resection volume with patient-reported outcomes applying different levels of oncoplastic breast conserving surgery - A retrospective cohort study.

INTRODUCTION: The American Society of Breast Surgeons (ASBrS) recently classified oncoplastic breast conserving surgery (OBCS) into two levels. The association of resection ratio during OBCS with patient-reported outcomes (PRO) is unclear. MATERIALS AND METHODS: Patients with stage 0-III breast cancer undergoing OBCS between 01/2011-04/2023 at a Swiss university hospital, who completed at least one postoperative BREAST-Q PRO questionnaire were identified from a prospectively maintained institutional database. Outcomes included differences in PROs between patients after ASBrS level I (<20 % of breast tissue removed) versus level II surgery (20-50 %). RESULTS: Of 202 eligible patients, 129 (63.9 %) underwent level I OBCS, and 73 (36.1 %) level II. Six patients (3.0 %) who underwent completion mastectomy were excluded. The median time to final PROs was 25.4 months. Patients undergoing ASBrS level II surgery were more frequently affected by delayed wound healing (p < 0.001). ASBrS level was not found to independently predict any BreastQ domain. However, delayed wound healing was shown to reduce short-term physical well-being (estimated difference -26.27, 95 % confidence interval [CI] -39.33 to -13.22, p < 0.001). Higher age was associated with improved PROs. CONCLUSION: ASBrS level II surgery allows the removal of larger tumors without impairing PROs. Preventive measures for delayed wound healing and close postoperative follow-up to promptly treat wound healing disorders may avoid short-term reductions in physical well-being.

Extracellular Vesicle DNA Extraction and Sequencing in Ancient Serum Samples From Patients With Breast Cancer.

BACKGROUND/AIM: Extracellular vesicle DNA (EV-DNA) has emerged as a novel biomarker for tumor mutation detection using liquid biopsies, exhibiting biological advantages compared to cell-free DNA (cfDNA). This study assessed the feasibility of EV-DNA and cfDNA extraction and sequencing in old serum samples of patients with breast cancer (BC). PATIENTS AND METHODS: A total of 28 serum samples of 27 patients with corresponding clinical information were collected between 1983 and 1991. EV-DNA was extracted using Exo-GAG kit (Nasabiotech) and cfDNA using QIAsymphony DSP Virus/Pathogen Midi Kit (Qiagen), respectively. Subsequently, 10 matched samples (EV-DNA n=5, cfDNA n=5) of five patients were subjected to sequencing using the Oncomine™ Breast cfDNA Research Assay v2 (Thermo Fisher Scientific). RESULTS: Samples were collected on median 1.9 years after primary diagnosis [interquartile range (IQR)=0.2-7.2]. Median follow-up was 9.5 years (IQR=5.2-14.2). Median age of serum samples was 36.1 years (IQR=34.5-37.3). EV-DNA and cfDNA were extracted from 100% (28/28) of the included samples. Both, DNA quantity and concentration were comparable between EV-DNA and cfDNA. Sequencing was successfully performed in 100% (10/10) of the included samples. Two matched analyses yielded equivalent results in EV-DNA and cfDNA (no mutations, n=1; PIK3CA mutation, n=1), whilst in two analyses, PIK3CA mutation was only found in cfDNA, and in one analysis, a TP53 mutation was only found in EV-DNA. CONCLUSION: EV-DNA extraction and sequencing in old serum samples of patients with BC is feasible and has the potential to address clinically relevant questions in longitudinal studies.

Omission of Axillary Dissection Following Nodal Downstaging With Neoadjuvant Chemotherapy.

Importance: Data on oncological outcomes after omission of axillary lymph node dissection (ALND) in patients with breast cancer that downstages from node positive to negative with neoadjuvant chemotherapy are sparse. Additionally, the best axillary surgical staging technique in this scenario is unknown. Objective: To investigate oncological outcomes after sentinel lymph node biopsy (SLNB) with dual-tracer mapping or targeted axillary dissection (TAD), which combines SLNB with localization and retrieval of the clipped lymph node. Design, Setting, and Participants: In this multicenter retrospective cohort study that was conducted at 25 centers in 11 countries, 1144 patients with consecutive stage II to III biopsy-proven node-positive breast cancer were included between April 2013 and December 2020. The cumulative incidence rates of axillary, locoregional, and any invasive (locoregional or distant) recurrence were determined by competing risk analysis. Exposure: Omission of ALND after SLNB or TAD. Main Outcomes and Measures: The primary end points were the 3-year and 5-year rates of any axillary recurrence. Secondary end points included locoregional recurrence, any invasive (locoregional and distant) recurrence, and the number of lymph nodes removed. Results: A total of 1144 patients (median [IQR] age, 50 [41-59] years; 78 [6.8%] Asian, 105 [9.2%] Black, 102 [8.9%] Hispanic, and 816 [71.0%] White individuals; 666 SLNB [58.2%] and 478 TAD [41.8%]) were included. A total of 1060 patients (93%) had N1 disease, 619 (54%) had ERBB2 (formerly HER2)-positive illness, and 758 (66%) had a breast pathologic complete response. TAD patients were more likely to receive nodal radiation therapy (85% vs 78%; P = .01). The clipped node was successfully retrieved in 97% of TAD cases and 86% of SLNB cases (without localization). The mean (SD) number of sentinel lymph nodes retrieved was 3 (2) vs 4 (2) (P < .001), and the mean (SD) number of total lymph nodes removed was 3.95 (1.97) vs 4.44 (2.04) (P < .001) in the TAD and SLNB groups, respectively. The 5-year rates of any axillary, locoregional, and any invasive recurrence in the entire cohort were 1.0% (95% CI, 0.49%-2.0%), 2.7% (95% CI, 1.6%-4.1%), and 10% (95% CI, 8.3%-13%), respectively. The 3-year cumulative incidence of axillary recurrence did not differ between TAD and SLNB (0.5% vs 0.8%; P = .55). Conclusions and Relevance: The results of this cohort study showed that axillary recurrence was rare in this setting and was not significantly lower after TAD vs SLNB. These results support omission of ALND in this population.

The American Society of Breast Surgeons classification system for oncoplastic breast conserving surgery independently predicts the risk of delayed wound healing.

INTRODUCTION: Oncoplastic breast conserving surgery (OBCS) aims to provide safe and satisfying surgery for breast cancer patients. The American Society of Breast Surgeons (ASBrS) classification system is based on volumetric displacement cut-offs (level I for <20% of breast volume; level II for 20-50%). It aims to facilitate communication among treating physicians and patients. Here, we investigate whether the extent of OBCS as classified by ASBrS independently predicts postoperative complications. MATERIALS AND METHODS: This retrospective analysis of a prospectively maintained database included patients with stage I-III breast cancer who underwent OBCS between 03/2011 and 12/2020 at a Swiss university hospital. Outcomes included short-term (≤30 days) complications and chronic (>30 days) pain after surgery. Multivariate logistic regression models were used to identify independent predictors. RESULTS: In total, 439 patients were included, 314 (71.5%) received ASBrS level I surgery, and 125 (28.5%) underwent ASBrS level II surgery. ASBrS level II was found to be an independent predictor of delayed wound healing (odds ratio [OR] 9.75, 95% confidence intervals (CI) 2.96-32.10). However, ASBrS level did not predict chronic postoperative pain (incidence rate ratio [IRR] 1.20, 95%CI 0.85-1.70), as opposed to age (IRR 1.19, 95%CI 1.11-1.27 per 5 years decrease), and weight disorders (underweight [BMI <18.5] vs. normal weight [BMI 18.5 < 25]: IRR 4.02, 95%CI 1.70-9.54; obese [BMI ≥30] vs. normal weight: IRR 2.07, 95%CI 1.37-3.13). CONCLUSION: ASBrS level II surgery predicted delayed wound healing, warranting close clinical follow-up and prompt treatment to avoid delays in adjuvant therapy.

Association of Axillary Dissection With Systemic Therapy in Patients With Clinically Node-Positive Breast Cancer.

Importance: The role of axillary lymph node dissection (ALND) to determine nodal burden to inform systemic therapy recommendations in patients with clinically node (cN)-positive breast cancer (BC) is currently unknown. Objective: To address the association of ALND with systemic therapy in cN-positive BC in the upfront surgery setting and after neoadjuvant chemotherapy (NACT). Design, Setting, and Participants: This was a prospective, observational, cohort study conducted from August 2018 to June 2022. This was a preplanned study within the phase 3 randomized clinical OPBC-03/TAXIS trial. Included were patients with confirmed cN-positive BC from 44 private, public, and academic breast centers in 6 European countries. After NACT, residual nodal disease was mandatory, and a minimum follow-up of 2 months was required. Exposures: All patients underwent tailored axillary surgery (TAS) followed by ALND or axillary radiotherapy (ART) according to TAXIS randomization. TAS removed suspicious palpable and sentinel nodes, whereas imaging-guidance was optional. Systemic therapy recommendations were at the discretion of the local investigators. Results: A total of 500 patients (median [IQR] age, 57 [48-69] years; 487 female [97.4%]) were included in the study. In the upfront surgery setting, 296 of 335 patients (88.4%) had hormone receptor (HR)-positive and Erb-B2 receptor tyrosine kinase 2 (ERBB2; formerly HER2 or HER2/neu)-negative disease: 145 (49.0%) underwent ART, and 151 (51.0%) underwent ALND. The median (IQR) number of removed positive lymph nodes without ALND was 3 (1-4) nodes compared with 4 (2-9) nodes with ALND. There was no association of ALND with the proportion of patients undergoing adjuvant chemotherapy (81 of 145 [55.9%] vs 91 of 151 [60.3%]; adjusted odds ratio [aOR], 0.72; 95% CI, 0.19-2.67) and type of systemic therapy. Of 151 patients with NACT, 74 (51.0%) underwent ART, and 77 (49.0%) underwent ALND. The ratio of removed to positive nodes was a median (IQR) of 4 (3-7) nodes to 2 (1-3) nodes and 15 (12-19) nodes to 2 (1-5) nodes in the ART and ALND groups, respectively. There was no observed association of ALND with the proportion of patients undergoing postneoadjuvant systemic therapy (57 of 74 [77.0%] vs 55 of 77 [71.4%]; aOR, 0.86; 95% CI, 0.43-1.70), type of postneoadjuvant chemotherapy (eg, capecitabine: 10 of 74 [13.5%] vs 10 of 77 [13.0%]; trastuzumab emtansine-DM1: 9 of 74 [12.2%] vs 11 of 77 [14.3%]), or endocrine therapy (eg, aromatase inhibitors: 41 of 74 [55.4%] vs 36 of 77 [46.8%]; tamoxifen: 8 of 74 [10.8%] vs 6 of 77 [7.8%]). Conclusion: Results of this cohort study suggest that patients without ALND were significantly understaged. However, ALND did not inform systemic therapy recommendations.

Uncertainties and controversies in axillary management of patients with breast cancer.

The aims of this Oncoplastic Breast Consortium and European Breast Cancer Research Association of Surgical Trialists initiative were to identify uncertainties and controversies in axillary management of early breast cancer and to recommend appropriate strategies to address them. By use of Delphi methods, 15 questions were prioritized by more than 250 breast surgeons, patient advocates and radiation oncologists from 60 countries. Subsequently, a global virtual consensus panel considered available data, ongoing studies and resource utilization. It agreed that research should no longer be prioritized for standardization of axillary imaging, de-escalation of axillary surgery in node-positive cancer and risk evaluation of modern surgery and radiotherapy. Instead, expert consensus recommendations for clinical practice should be based on current evidence and updated once results from ongoing studies become available. Research on de-escalation of radiotherapy and identification of the most relevant endpoints in axillary management should encompass a meta-analysis to identify knowledge gaps, followed by a Delphi process to prioritize and a consensus conference to refine recommendations for specific trial designs. Finally, treatment of residual nodal disease after surgery was recommended to be assessed in a prospective register.

Axillary surgery in node-positive breast cancer.

Long-term follow-up data from multicenter phase III non-inferiority trials confirmed the safety of omission of axillary dissection in selected patients with clinically node-negative, sentinel node-positive breast cancer. Several ongoing trials investigate extended eligibility of the Z0011 protocol in the adjuvant setting. De-escalation of axillary surgery in patients with clinically node-positive breast cancer is currently limited to the neoadjuvant setting, where the sentinel procedure is used to determine nodal pathological complete response. Targeted axillary dissection lowers the false-negative rate of the sentinel procedure, which, however, is consistently associated with a very low risk of axillary recurrence in several recent single-center series. Axillary dissection remains standard care in patients with residual disease after neoadjuvant chemotherapy while the results of Alliance A011202 are pending. The TAXIS trial investigates the role of tailored axillary surgery in patients with clinically node-positive breast cancer, a novel concept designed to selectively remove positive nodes in the adjuvant and neoadjuvant setting.

Exposure to escalating olaparib does not induce acquired resistance to PARPi and to other chemotherapeutic compounds in ovarian cancer cell lines.

Poly (ADP­ribose) polymerase (PARP)­inhibitors (PARPi) such as olaparib and niraparib are currently used as a treatment option for BRCA­deficient tumors and also show efficacy in platinum­sensitive tumors. However, resistance to PARPi occurs in numerous patients and in particular acquired PARPi resistance presents a major obstacle in the treatment of these tumors. In the present study, it was investigated whether stepwise exposure of ovarian cancer cells to escalating concentrations of olaparib produced subcells with acquired resistance to PARPi and/or acquired cross­resistance to platinum compounds, paclitaxel, and doxorubicin. To this aim, the sensitivity of fourteen ovarian cancer cell lines, including nine with TP53­mutations and five carrying BRCA­mutations, to olaparib and niraparib was determined and a subset of seven cell lines was selected to investigate the potential of olaparib to produce resistance. It was identified that escalating olaparib did neither produce subcells with acquired PARPi­resistance nor did it produce acquired cross­resistance to platinum compounds, doxorubicin, and paclitaxel. This finding was independent of the cells' TP53 and BRCA mutation status. CRISPR­Cas9 mediated deletion of PARP1 did not affect sensitivity to PARPi, platinum compounds, doxorubicin, and paclitaxel. In addition, olaparib sensitivity correlated with niraparib sensitivity, but BRCA­mutated cells were not more sensitive to PARPi. Moreover, PARPi sensitivity associated with cross­sensitivity not only to platinum compounds but also to anthracylines, paclitaxel, and inhibitors of histone deacetylases. These in vitro data indicated that olaparib exposure is unlikely to produce an acquired resistance phenotype and that PARPi­sensitive ovarian cancer cells are also cross­sensitive to non­platinum and even to compounds not directly interacting with the DNA.

Prepectoral implant-based breast reconstruction with TiLOOP® Bra Pocket - a single-centre retrospective study.

BACKGROUND: Prepectoral implant-based reconstruction using synthetic meshes is feasible with good outcomes. We present our data using TiLOOP® Bra Pocket, a novel ready-to-use mesh pocket which acts as an internal bra and prevents the implant from dislocating or twisting. MATERIALS AND METHODS: A single-centre retrospective cohort study was performed to assess short-term complication rates and cosmetic outcomes in patients with prepectoral implant-based reconstruction using the TiLOOP® Bra Pocket. The primary endpoint was complication rates during the first 6 months. The secondary endpoint was the cosmetic outcome after 6 to 12 months, which was judged by two breast surgeons using the Harvard score. RESULTS: A total of 63 breasts (43 patients) were reconstructed using the TiLOOP® Bra Pocket between 2018 and 2020, 57 were immediate reconstructions. The overall complication rate was 30,2% (n = 19/63). Major complications occurred in seven breasts (n = 7/63; 11,1%) and minor complications occurred in 12 breasts (12/63; 19,0%). The unplanned revision rate was 12,7%. The cosmetic outcome was good (Harvard score: mean 3, range 1-4; SD 0,75). Seventeen cosmetic complications were observed (17/63; 27,0%) and six cosmetic revision surgeries were performed (6/63; 9,5%). CONCLUSION: The use of the TiLOOP® Bra Pocket is convenient and standardized because the pocket is preformed and does not require to be sewn first. Cosmetic outcome is good; however, the surgical morbidity needs to be addressed in future reconstructions. Careful patient selection and preparation techniques are vital in order to achieve acceptable complication rates and satisfying cosmetic results.

The impact of delayed wound healing on patient-reported outcomes after breast cancer surgery.

PURPOSE: Postoperative complications after breast cancer surgery may be associated with decreased quality of life. It remains unclear whether oncoplastic breast-conserving surgery or mastectomy with reconstruction lead to more postoperative complications than conventional breast surgery (CBS). As delayed wound healing (DWH) is one of the most frequent minor complications, we sought to investigate the significance of DWH for patient-reported outcomes after oncoplastic, reconstructive, and CBS. METHODS: Our study is a retrospective cohort study of consecutive patients with stage I-II breast cancer who underwent oncoplastic or CBS performed by three breast surgeons at a single tertiary referral hospital from June 2011 until May 2019. Patient-reported outcomes were evaluated postoperatively using the BREAST-Q questionnaire. Comparisons were made between patients with and without DWH. RESULTS: A total of 229 patients who met the inclusion criteria and 28 (12%) of them developed DWH, 27/158 (17%) in the oncoplastic breast-conserving surgery and reconstruction group and 1/71 (1%) in the CBS group. The mean time from surgery to BREAST-Q assessment was comparable in both groups (29 months in the DWH vs. 33 months in the normal wound healing group). No statistically significant difference for any BREAST-Q scale was detected between patients with and without DWH. This includes physical (p = 0.183), psychosocial (p = 0.489), sexual well-being (p = 0.895), and satisfaction with breasts (p = 0.068). CONCLUSION: Our study confirms that oncoplastic breast-conserving surgery and mastectomy with reconstruction lead to significantly more DWH than CBS. However, neither quality of life nor patient-reported outcomes following state-of-the-art reconstructive or oncoplastic breast-conserving surgery at a specialized center seem to be compromised.

Tailored axillary surgery in patients with clinically node-positive breast cancer: Pre-planned feasibility substudy of TAXIS (OPBC-03, SAKK 23/16, IBCSG 57-18, ABCSG-53, GBG 101).

AIM: We developed tailored axillary surgery (TAS) to reduce the axillary tumor volume in patients with clinically node-positive breast cancer to the point where radiotherapy can control it. The aim of this study was to quantify the extent of tumor load reduction achieved by TAS. METHODS: International multicenter prospective study embedded in a randomized trial. TAS is a novel pragmatic concept for axillary surgery de-escalation that combines palpation-guided removal of suspicious nodes with the sentinel procedure and, optionally, imaging-guided localization. Pre-specified study endpoints quantified surgical extent and reduction of tumor load. RESULTS: A total of 296 patients were included at 28 sites in four European countries, 125 (42.2%) of whom underwent neoadjuvant chemotherapy (NACT) and 71 (24.0%) achieved nodal pathologic complete response. Axillary metastases were detectable only by imaging in 145 (49.0%) patients. They were palpable in 151 (51.0%) patients, of whom 63 underwent NACT and 21 had residual palpable disease after NACT. TAS removed the biopsied and clipped node in 279 (94.3%) patients. In 225 patients with nodal disease at the time of surgery, TAS removed a median of five (IQR 3-7) nodes, two (IQR 1-4) of which were positive. Of these 225 patients, 100 underwent ALND after TAS, which removed a median of 14 (IQR 10-17) additional nodes and revealed additional positive nodes in 70/100 (70%) of patients. False-negative rate of TAS in patients who underwent subsequent ALND was 2.6%. CONCLUSIONS: TAS selectively reduced the tumor load in the axilla and remained much less radical than ALND.