RAD51 foci as a functional biomarker of homologous recombination repair and PARP inhibitor resistance in germline BRCA-mutated breast cancer.

Background: BRCA1 and BRCA2 (BRCA1/2)-deficient tumors display impaired homologous recombination repair (HRR) and enhanced sensitivity to DNA damaging agents or to poly(ADP-ribose) polymerase (PARP) inhibitors (PARPi). Their efficacy in germline BRCA1/2 (gBRCA1/2)-mutated metastatic breast cancers has been recently confirmed in clinical trials. Numerous mechanisms of PARPi resistance have been described, whose clinical relevance in gBRCA-mutated breast cancer is unknown. This highlights the need to identify functional biomarkers to better predict PARPi sensitivity. Patients and methods: We investigated the in vivo mechanisms of PARPi resistance in gBRCA1 patient-derived tumor xenografts (PDXs) exhibiting differential response to PARPi. Analysis included exome sequencing and immunostaining of DNA damage response proteins to functionally evaluate HRR. Findings were validated in a retrospective sample set from gBRCA1/2-cancer patients treated with PARPi. Results: RAD51 nuclear foci, a surrogate marker of HRR functionality, were the only common feature in PDX and patient samples with primary or acquired PARPi resistance. Consistently, low RAD51 was associated with objective response to PARPi. Evaluation of the RAD51 biomarker in untreated tumors was feasible due to endogenous DNA damage. In PARPi-resistant gBRCA1 PDXs, genetic analysis found no in-frame secondary mutations, but BRCA1 hypomorphic proteins in 60% of the models, TP53BP1-loss in 20% and RAD51-amplification in one sample, none mutually exclusive. Conversely, one of three PARPi-resistant gBRCA2 tumors displayed BRCA2 restoration by exome sequencing. In PDXs, PARPi resistance could be reverted upon combination of a PARPi with an ataxia-telangiectasia mutated (ATM) inhibitor. Conclusion: Detection of RAD51 foci in gBRCA tumors correlates with PARPi resistance regardless of the underlying mechanism restoring HRR function. This is a promising biomarker to be used in the clinic to better select patients for PARPi therapy. Our study also supports the clinical development of PARPi combinations such as those with ATM inhibitors.

Characterization of male breast cancer: results of the EORTC 10085/TBCRC/BIG/NABCG International Male Breast Cancer Program.

Background: Male breast cancer (BC) is rare, managed by extrapolation from female BC. The International Male BC Program aims to better characterize and manage this disease. We report the results of part I, a retrospective joint analysis of cases diagnosed during a 20-year period. Methods: Patients with follow-up and tumor samples, treated between 1990 and 2010, in 93 centers/9 countries. Samples were centrally analyzed in three laboratories (the United Kingdom, the Netherlands and the United States). Results: Of 1822 patients enrolled, 1483 were analyzed; 63.5% were diagnosed between 2001 and 2010, 57 (5.1%) had metastatic disease (M1). Median age at diagnosis: 68.4 years. Of 1054 M0 cases, 56.2% were node-negative (N0) and 48.5% had T1 tumors; 4% had breast conserving surgery (BCS), 18% sentinel lymph-node biopsy; half received adjuvant radiotherapy; 29.8% (neo)adjuvant chemotherapy and 76.8% adjuvant endocrine therapy (ET), mostly tamoxifen (88.4%). Per central pathology, for M0 tumors: 84.8% ductal invasive carcinomas, 51.5% grade 2; 99.3% estrogen receptor (ER)-positive; 81.9% progesterone receptor (PR)-positive; 96.9% androgen receptor (AR)-positive [ER, PR or AR Allred score ≥3]; 61.1% Ki67 expression low (<14% positive cells); using immunohistochemistry (IHC) surrogates, 41.9% were Luminal-A-like, 48.6% Luminal-B-like/HER-2-negative, 8.7% HER-2-positive, 0.3% triple negative. Median follow-up: 8.2 years (0.0-23.8) for all, 7.2 years (0.0-23.2), for M0, 2.6 years (0.0-12.7) for M1 patients. A significant improvement over time was observed in age-corrected BC mortality. BC-specific-mortality was higher for men younger than 50 years. Better overall (OS) and recurrence-free survival (RFS) were observed for highly ER+ (P = 0.001), highly PR+ (P = 0.002), highly AR+ disease (P = 0.019). There was no association between OS/RFS and HER-2 status, Ki67, IHC subtypes nor grade. Conclusions: Male BC is usually ER, PR and AR-positive, Luminal B-like/HER2-negative. Of note, 56% patients had T1 tumors but only 4% had BCS. ER was highly positive in >90% of cases but only 77% received adjuvant ET. ER, PR and AR were associated with OS and RFS, whereas grade, Ki67 and IHC surrogates were not. Significant improvement in survival over time was observed.

Meta-analysis of tumour burden in pre-operative axillary ultrasound positive and negative breast cancer patients.

BACKGROUND: Management of the axilla in breast cancer is becoming increasingly conservative. Patients identified with a low axillary nodal burden (two or fewer involved nodes) at sentinel node biopsy (SNB) can avoid completion axillary node clearance (cANC). 'Fast track' to ANC in patients with involved nodes on pre-operative ultrasound may be over-treating a subgroup of these patients with low nodal burden, which would have precluded their need for ANC. This systematic review assesses the proportion of patients with involved nodes on pre-operative axillary ultrasound, which would fit low axillary burden criteria. METHODS: Meta-analysis of studies comparing axillary burden of breast cancer patients identified as pre-operative ultrasound negative versus positive was performed. The primary outcome measure was the number of patients with two or fewer involved nodes (macrometastases only). Pooled odds ratio (OR), 95% confidence intervals (CIs), means and probabilities of identifying two or fewer involved nodes versus greater than two were calculated. RESULTS: Six studies reported the axillary burden in 4271 patients who were either directed straight to ANC or cANC after SNB. There was a significantly greater axillary burden in the ultrasound positive versus negative groups (OR 5.95, 95% CI 5.80-6.11) with mean nodal retrieval values of 2.9 [standard error (SE) 0.2] and 1.6 (SE 0.2) nodes, respectively. Cumulative probabilities identified 78.9% of ultrasound negative and 43.2% of ultrasound positive patients possessed low axillary burden. CONCLUSIONS: Pre-operative ultrasound positive patients have significantly higher axillary burden. However, nearly half do fit the criteria of low axillary burden and could be considered for omission of ANC.

Meta-analysis of aberrant lymphatic drainage in recurrent breast cancer.

BACKGROUND: Sentinel node biopsy (SNB) in recurrent breast cancer offers targeted axillary staging compared with axillary lymph node dissection (ALND) or no treatment. The evidence for lymphatic mapping in recurrent breast cancer is reviewed, focusing on aberrant drainage and its implications for patient management. METHODS: A meta-analysis of studies evaluating lymphatic mapping in recurrent breast cancer was performed. Outcomes included sentinel node identification, aberrant lymphatic pathways and metastatic node rates in aberrant drainage and ipsilateral axilla. Pooled odds ratios (ORs) and 95 per cent confidence intervals (c.i.) were estimated using fixed-effect analyses, or random-effects analyses in the event of statistically significant heterogeneity. RESULTS: Seven studies reported data on lymphatic mapping in 1053 patients with recurrent breast cancer. The intraoperative sentinel node identification rate was 59·6 (95 per cent c.i. 56·7 to 62·6) per cent, and significantly greater when the original axillary surgery was SNB compared with ALND (OR 2·97, 95 per cent c.i. 1·66 to 5·32). The rate of aberrant lymphatic drainage identification was 25·7 (23·0 to 28·3) per cent, and significantly greater when the original axillary surgery was ALND (OR 0·27, 0·19 to 0·38). The metastatic sentinel node rate was 10·4 (8·6 to 12·3) per cent, and a significantly greater metastatic nodal burden was identified in the ipsilateral axilla (OR 6·31, 1·03 to 38·79). CONCLUSION: Lymphatic mapping is feasible in recurrent breast cancer. It avoids ALND in over 50 per cent of patients who have undergone SNB, and allows the 4 per cent of patients with metastatically involved aberrant nodes to receive targeted surgical and adjuvant therapies.

Systematic review of axillary reverse mapping in breast cancer.

BACKGROUND: Axillary reverse mapping (ARM) assesses the lymphatic drainage of the arm simultaneously with that of the breast, enabling preservation of arm lymphatics during axillary surgery for breast cancer. This article systematically reviews the evidence on the lymphoedema rate and oncological safety of the ARM technique. METHODS: PubMed, Embase and the Cochrane Library were searched systematically for studies that addressed the use of ARM during axillary surgery in breast cancer. Studies were eligible if they performed ARM during sentinel node biopsy (SNB) or axillary node clearance (ANC) for breast cancer in prospective studies of more than 50 patients, with assessment of lymphoedema and oncological outcomes during a minimum follow-up of 6 months. RESULTS: Eight studies reported data on ARM in 1142 patients undergoing axillary surgery for breast cancer. Lymphoedema rates ranged from 0 to 6 per cent during ARM-assisted SNB, and from 5.9 to 24 per cent during ARM lymphatic preservation at ANC. Crossover nodes between the arm and breast lymphatics were identified in 0-10 per cent of patients, and metastases were present in 0-20 per cent of these patients. ARM nodes were not preserved in between 11 and 18 per cent of patients with ARM nodes identified, and metastases were detected in 0-19 per cent of these patients. CONCLUSION: ARM can achieve low rates of lymphoedema, but the risk of metastasis in crossover and clinically suspicious ARM nodes, or those in close proximity to an involved sentinel node, warrants their excision.

Factors associated with surgical management following neoadjuvant therapy in patients with primary HER2-positive breast cancer: results from the NeoALTTO phase III trial.

BACKGROUND: The NeoALTTO trial showed that dual HER2 blockade nearly doubles the rate of pathologic complete response (pCR) in patients with primary HER2-positive breast cancer. However, this did not translate into a higher rate of breast-conserving surgery (BCS). PATIENTS AND METHODS: In NeoALTTO, patients with HER2-positive breast cancer were randomly assigned to either trastuzumab, lapatinib or their combination with paclitaxel before surgery with pCR as the primary end point. We investigated the association between the surgery type and clinicopathological factors and response to treatment, adjusting for the treatment arm. RESULTS: Four hundred and twenty-nine patients were subjected to breast surgery. Two hundred and forty-two (56%) and 187 (44%) patients underwent mastectomy and BCS, respectively. In a logistic regression model, negative estrogen receptor (ER), multicentricity and the presence of a palpable mass before surgery were significantly associated with a low chance of BCS. Conversely, patients with small tumors and those eligible for BCS at diagnosis were managed more with BCS, independent of the treatment arm. Radiological response was not associated with the surgical decision. CONCLUSIONS: Tumor characteristics before neoadjuvant therapy play a main role in deciding the type of surgery calling for a clear consensus on the role of BCS in patients responding to neoadjuvant therapy.

Management of the axilla in early breast cancer patients in the genomic era.

Management of the axilla in early breast cancer (EBC) patients has dramatically evolved in recent years from more radical to increasingly conservative approaches. Classically, the EBC patients with a clinically positive axilla are offered axillary lymph node dissection (ALND) and those with a clinically negative axilla (cN0) are offered sentinel lymph node (SLN) biopsy, which obviates the complications related to ALND and provides adequate surgical staging and comparable locoregional control and survival. The need for performing ALND when the SLN is positive and contemporary adjuvant treatment is delivered has been questioned in recent years. On the other hand, ongoing trials are testing whether node-positive patients can be spared chemotherapy, based on intrinsic primary tumor biology. Because the integration of novel surgical management and tumor biology is needed, this article provides an overview of the current challenges that a more detailed knowledge of tumor biology has brought to EBC staging and treatment. We propose that breast cancer oncologists (surgeons, radiation therapists, and medical oncologists) should focus their efforts on offering therapy tailored to each patient's needs in such a way that no matter which treatment is used, no overtreatment occurs.

EUSOMA position regarding breast implant associated anaplastic large cell lymphoma (BIA-ALCL) and the use of textured implants.

During the last two decades the number of breast implants used in aesthetic, oncologic and risk reducing surgery has increased substantially mainly due to the improvement and confirmed safety of these devices. Since identification of the first case of anaplastic large cell lymphoma associated with a breast implant (BIA-ALCL) 20 years ago, there has been an increase in the number of reports of this very rare disease, demonstrating a clear association with breast implants. Whilst the majority of cases are localised and cured by implant removal and full capsulectomy, a small percentage require chemotherapy and the mortality rate is very low. The evidence linking BIA-ALCL to implant surface texturing, as the majority of cases were diagnosed in patients with textured implants, has raised concerns about the long term safety of these devices resulting in patient and regulatory authority concerns globally. We hereby present the current published knowledge about the link between BIA-ALCL and implant surface texture and a review of current regulatory and professional body advice across Europe, which may enable a better understanding of this rare disease, how to manage and ultimately prevent it. We conclude by giving EUSOMA recommendation, towards the unnecessary change in attitudes towards implant based surgery, according to the most recent available published evidence as long as patients are properly informed about the risk of BIA-ALCL.

Variability in breast cancer surgery training across Europe: An ESSO-EUSOMA international survey.

BACKGROUND: At present there is a lack of standardization of training in breast cancer surgery across Europe. The aim of this survey was to assess current practice in Europe regarding training in breast cancer (BC) surgery. MATERIAL AND METHODS: General surgeons, surgical oncologists, gynecologist, and plastic surgeons in Europe were invited to participate in this bespoke survey including 19 questions. RESULTS: The survey was sent to 3.000 surgical oncologists across Europe. A total of 671 physicians (387 general surgeons, 152 gynecologists, 126 surgical oncologist, 31 plastic surgeons) answered the survey (23% response rate). Four hundred and sixty-eight physicians devoted between 50% -100% of their job to treating breast cancer. 45% worked in a community/University hospital within a dedicated Breast Unit. Specific additional breast surgery training was not universal: 20% had undertaken an accredited breast fellowship, 30% in a Breast Unit as a trainee, 21% had done additional courses, masters or diploma and 8% had not done any additional training. The majority (61%) of respondents worked in Units treating >150 BC cases per year, while 26% of the responders treat >120 new primary cases per year, and 23% less than 50 new cases a year. Multivariate analysis showed that breast surgeons working in a Breast Unit and treating more than 50 cases/year significantly performed oncoplastic procedures. CONCLUSION: There is a great variability in breast cancer surgery training in Europe. It is imperative to develop quality standards for breast cancer surgery training to ensure that patients get standardized and certified surgical management regardless of the country in which they are treated.

European Society of Surgical Oncology's strategy for clinical research: Paving the way for a culture of research in cancer surgery.

As part of its mission to promote the best surgical care for cancer patients, the European Society of Surgical Oncology (ESSO) has been developing multiple programmes for clinical research along with its educational portfolio. This position paper describes the different research activities of the Society over the past decade and an action plan for the upcoming five years to lead innovative and high quality surgical oncology research. ESSO proposes to consider pragmatic research methodologies as a complement to randomised clinical trials (RCT), advocates for increased funding and operational support in conducting research and aims to enable young surgeons to be active in research and establish partnerships for translational research activities.

Perspectives on preoperative systemic treatment and breast conservative surgery: One step forward or two steps back?

Preoperative systemic therapy (PST) has become an accepted treatment not only for locally advanced but also for early stage breast cancer patients. Clinical trials have demonstrated that the use of PST is equally to adjuvant treatments in terms of overall survival, and has the advantage of increasing rates of breast conservative surgery and rates of pathologic complete response, a surrogate endpoint for the effectiveness of systemic therapy. Initial studies have suggested higher rates of locoregional recurrence with this approach. However, the optimization of systemic and targeted therapy and the multidisciplinary care is key to achieving optimal outcomes in this setting.

Sentinel lymph node biopsy after neoadjuvant treatment in breast cancer: Work in progress.

Sentinel lymph node biopsy has replaced axillary lymph node dissection (ALND) in those patients with clinically node negative axilla and nowadays, patients with low burden disease in the SLNs may spare an ALND without compromising their oncologic outcomes. In the last decade, indications of neoadjuvant treatment (NAT) have been extended to patients with operable disease and with the use of targeted therapies, rates of pathologic complete response (pCR) after NAT have increased. In the neoadjuvant setting, SLN after NAT is feasible and accurate in clinically node negative patients and it has been explored in different randomized prospective studies in patients with clinically positive axilla in the continuous effort to avoid the morbidity of ALND. The importance of identifying patients with residual axillary disease may serve not only as indicator for selecting patients with pCR to be spared an ALND but also for selecting patients for additional therapy. Future research is needed to more accurately identify residual axillary disease and the SLN after NAT is the driver for this achievement.

Margins in breast conserving surgery: A practice-changing process.

Margins in breast conserving surgery (BCS) have been a long standing subject debate. This largely arises from the absence of a consensus on what constitutes an adequate margin width, resulting in re-excision rates of 25-40% for close or positive margins and its consequent impact upon cosmesis, economic costs, patient dissatisfaction and lack of bearing on survival. Accepting that the increased risk of local recurrences (LR) has its influence on survival, the decrease in LR in BCS in the last decade have been motivated by better surgical techniques for assessing negative margins, use of targeted therapies and in general with the multimodal treatment in the management of breast cancer patients. Since the publication of the consensus guidelines on margins there has evolved a trend of changing attitudes towards re-excision. Surgeons are considering margins in the context of all factors including not only patient and tumor characteristics but also the regional and systemic treatment the patient is receiving.