Breast Conservation After Neoadjuvant Chemotherapy for Triple-Negative Breast Cancer: Surgical Results From the BrighTNess Randomized Clinical Trial

Systemic Therapy De-Escalation in Early-Stage Triple-Negative Breast Cancer: Dawn of a New Era?

Simple Summary

Triple-negative breast cancer is a life-threatening disease, even when identified at early stages. Recent advances have allowed the improvement of life expectancy via a personalized approach with the addition of newer chemotherapies, immunotherapies, and targeted therapies, but at the cost of added side effects. It has become increasingly clear that not all patients need such aggressive treatment. Here, we provide an overview of emerging opportunities to use less toxic therapies in patients at lower risk of recurrence or with mutations that can be effectively targeted using novel approaches. We provide a comprehensive review of completed and ongoing clinical trials with information on how to best stratify these patients for treatments to obtain maximum benefit without unnecessary toxicities.

Abstract

Early-stage triple negative breast cancer (TNBC) has been traditionally treated with surgery, radiation, and chemotherapy. The current standard of care systemic treatment of early-stage II and III TNBC involves the use of anthracycline-cyclophosphamide and carboplatin-paclitaxel with pembrolizumab in the neoadjuvant setting followed by adjuvant pembrolizumab per KEYNOTE-522. It is increasingly clear that not all patients with early-stage TNBC need this intensive treatment, thus paving the way for exploring opportunities for regimen de-escalation in selected subgroups. For T1a tumors (≤5 mm), chemotherapy is not used, and for tumors 6–10 mm (T1b) in size with negative lymph nodes, retrospective studies have failed to show a significant benefit with chemotherapy. In low-risk patients, anthracycline-free chemotherapy may be as effective as conventional therapy, as shown in some studies where replacing anthracyclines with carboplatin has shown non-inferior results for pathological complete response (pCR), which may form the backbone of future combination therapies. Recent advances in our understanding of TNBC heterogeneity, mutations, and surrogate markers of response such as pCR have enabled the development of multiple treatment options in the (neo)adjuvant setting in order to de-escalate treatment. These de-escalation studies based on tumor mutational status, such as using Poly ADP-ribose polymerase inhibitors (PARPi) in patients with BRCA mutations, and new immunotherapies such as PD1 blockade, have shown a promising impact on pCR. In addition, the investigational use of (bio)markers, such as high levels of tumor-infiltrating lymphocytes (TILs), low levels of tumor-associated macrophages (TAMs), and complete remission on imaging, also look promising. In this review, we cover the current standard of care systemic treatment of early TNBC and review the opportunities for treatment de-escalation based on clinical risk factors, biomarkers, mutational status, and molecular subtype.

Neoadjuvant approach in patients with early breast cancer: patient assessment, staging, and planning

Neoadjuvant treatment (NAT) has become an option in early stage (stage I-II) breast cancer (EBC). New advances in systemic and targeted therapies have increased rates of pathologic complete response increasing the number of patients undergoing NAT. Clear benefits of NAT are downstaging the tumor and the axillary nodes to de-escalate surgery and to evaluate response to treatment. Selection of patients for NAT in EBC rely in several factors that are related to patient characteristics (i.e, age and comorbidities), to tumor histology, to stage at diagnosis and to the potential changes in surgical or adjuvant treatments when NAT is administered.

Imaging and histologic confirmation is performed to assess extent of disease y to confirm diagnosis. Besides mammogram and ultrasound, functional breast imaging MRI has been incorporated to better predict treatment response and residual disease. Contrast enhanced mammogram (CEM), shear wave elastography (SWE), or Dynamic Optical Breast Imaging (DOBI) are emerging techniques under investigation for assessment of response to neoadjuvant therapy as well as for predicting response. Surgical plan should be delineated after NAT taking into account baseline characteristics, tumor response and patient desire.

In the COVID era, we have witnessed also the increasing use of NAT in patients who may be directed to surgery, unable to have it performed as surgery has been reserved for emergency cases only.

A Canadian national guideline on the neoadjuvant treatment of invasive breast cancer, including patient assessment, systemic therapy, and local management principles

Purpose

The neoadjuvant treatment of breast cancer (NABC) is a rapidly changing area that benefits from guidelines integrating evidence with expert consensus to help direct practice. This can optimize patient outcomes by ensuring the appropriate use of evolving neoadjuvant principles.

Methods

An expert panel formulated evidence-based practice recommendations spanning the entire neoadjuvant breast cancer treatment journey. These were sent for practice-based consensus across Canada using the modified Delphi methodology, through a secure online survey. Final recommendations were graded using the GRADE criteria for guidelines. The evidence was reviewed over the course of guideline development to ensure recommendations remained aligned with current relevant data.

Results

Response rate to the online survey was almost 30%; representation was achieved from various medical specialties from both community and academic centres in various Canadian provinces. Two rounds of consensus were required to achieve 80% or higher consensus on 59 final statements. Five additional statements were added to reflect updated evidence but not sent for consensus.

Conclusions

Key highlights of this comprehensive Canadian guideline on NABC include the use of neoadjuvant therapy for early stage triple negative and HER2 positive breast cancer, with subsequent adjuvant treatments for patients with residual disease. The use of molecular signatures, other targeted adjuvant therapies, and optimal response-based local regional management remain actively evolving areas. Many statements had evolving or limited data but still achieved high consensus, demonstrating the utility of such a guideline in helping to unify practice while further evidence evolves in this important area of breast cancer management.

A Retrospective Cohort Study Comparing Traditional Breast Conservation With Oncoplastic Surgery in Breast Cancer Patients After Neoadjuvant Chemotherapy

BACKGROUND

To better understand the difference between traditional breast-conserving surgery (BCS) and oncoplastic surgery (OPS), we conducted a retrospective cohort study involving breast cancer patients who received neoadjuvant chemotherapy (NAC) and then underwent breast conservation at the Fudan University Shanghai Cancer Center.

METHODS

A retrospective chart review was conducted. All breast cancer patients who received NAC and then underwent traditional BCS or OPS at the Fudan University Shanghai Cancer Center from January 1, 2008, to December 31, 2019, were included.

RESULTS

Three hundred ninety-nine breast cancer patients received NAC and underwent traditional BCS, and 99 patients underwent OPS. The average age of the patients in the OPS group was younger than that in the BCS group (43 vs 48 years, P = 0.017). The size of the tumor assessed by ultrasonography at baseline in the OPS group was larger than that in the BCS group (31.3 vs 28.1 mm, P = 0.013). The same trend was observed in the clinical T stage and overall staging assessments before the administration of NAC in these 2 groups. Oncoplastic techniques were more frequently applied when tumors were located in areas with relatively few glands, such as the upper inner quadrant. There were no significant differences in the margins and distributions of pathological types and molecular subtypes between these 2 groups. The rates of pathological complete response were similar in the traditional BCS and OPS groups.

CONCLUSIONS

Unlike traditional BCS, in breast cancer patients after NAC, the adoption of oncoplastic techniques makes breast conservation feasible, even in patients with large tumors, late stages, and unfavorable tumor locations.

Laser activatable nanographene colloids for chemo-photothermal combined gene therapy of triple-negative breast cancer

This investigation reports the green approach for developing laser activatable nanoscale-graphene colloids (nGC-CO-FA) for chemo-photothermal combined gene therapy of triple-negative breast cancer (TNBC). The nano colloid was found to be nanometric as characterized by SEM, AFM, and zeta sizer (68.2 ± 2.1 nm; 13.8 ± 1.2 mV). The doxorubicin (Dox) loaded employing hydrophobic interaction/π-π stacking showed >80% entrapment efficiency with a sustained pH-dependent drug release profile. It can efficiently incorporate siRNA and Dox and successfully co-localize them inside TNBC cells to obtain significant anticancer activity as evaluated using CCK-8 assay, apoptosis assay, cell cycle analysis, cellular uptake, fluorescence assay, endosomal escape study, DNA content analysis, and gene silencing efficacy studies. nGC-CO-FA/Dox/siRNA released the Dox in temperature- and a pH-responsive manner following NIR-808 laser irradiation. The synergistic photo-chemo-gene therapy using near infrared-808 nm laser (NIR-808) irradiation was found to be more effective as compared to without NIR-808 laser-treated counterparts (∆T: 37 ± 1.1 °C → to 49.2 ± 3.1 °C; 10 min; 0.5 W/cm²), suggesting the pivotal role of photothermal combined gene-therapy in the treatment of TNBC.

Oncologic outcomes of immediate breast reconstruction in young women with breast cancer receiving neoadjuvant chemotherapy

BACKGROUND

Oncologic safety of postmastectomy breast reconstruction in young women with breast cancer is not well-defined, especially in the setting of neoadjuvant chemotherapy (NACT). We retrospectively compared the oncologic outcomes following nipple-sparing (NSM)/skin-sparing mastectomy (SSM) with immediate breast reconstruction (IBR) and conventional mastectomy (CM) alone in young breast cancer patients after NACT.

METHODS

A total of 1266 women with primary breast cancer who underwent NACT followed by total mastectomy with or without IBR were reviewed. Of these, only young patients (age ≤ 40 years at diagnosis) were included in the outcome analysis (n = 375). After propensity score-matching by clinical T and N stage, molecular subtype, response to NACT, and adjuvant radiotherapy status, 228 patients were 1:1 matched, comprising balanced IBR group (with NSM/SSM) and CM-alone group.

RESULTS

The 5-year locoregional recurrence-free, disease-free, distant metastasis (DM)-free, and breast cancer-specific survival (BCSS) rates for the entire cohort of young patients were 83.4%, 65.3%, 71.7%, and 85.4%, respectively. Locoregional recurrence rates between the matched groups were similar (14% vs. 15.8%; p = 0.710); however, IBR group had significantly lower DM rate (27.2% vs. 40.4%; p = 0.036) and breast cancer mortality (14.9% vs. 27.2%; p = 0.023) than CM-alone group. IBR group showed significantly improved 5-year DM-free survival (74.1% vs. 62.6%; p = 0.043) and BCSS (89.1% vs. 77.6%; p = 0.048) rates than CM-alone group.

CONCLUSIONS

Our results indicated that IBR with NSM/SSM does not negatively affect long-term oncologic outcomes compared to CM alone in young women with breast cancer receiving NACT.

Pan-cancer analysis reveals homologous recombination deficiency score as a predictive marker for immunotherapy responders

The immune context of the tumor microenvironment (TME) is critical for effective immunotherapy. Nonetheless, DNA-based biomarkers for the immune-sensitive TME and the identification of immune checkpoint inhibitor (ICI) responders are under-explored. This study aims to comprehensively landscape the homologous recombination deficiency (HRD) score, an emerging hallmark for tumor genome instability that triggers immune responsiveness across major cancer types, and to unveil their link to the TME and immunotherapeutic response. The HRD-associated genomic scars were characterized in 9088 tumor samples across 32 cancer types from TCGA. We evaluated the HRD score's performance in classifying ICI responders using an independent breast cancer cohort (GSE87049) and 11 in vivo murine mammary tumor models treated with anti-PD1/CTLA4 regimen (GSE124821). This study revealed a broad association between HRD-high genotype and neoantigenesis in the major cancer types including bladder cancer, breast cancer, head and neck squamous carcinoma, lung adenocarcinoma, lung squamous cell carcinoma, ovarian cancer, and sarcoma. Tumors with high HRD score bears increased leukocyte infiltration and lymphocyte fraction and demonstrated immune-sensitive microenvironment. The tumor immune dysfunction and exclusion (TIDE) model further confirmed HRD score-high genotype as a potential predictor for ICI immunotherapy responders in breast cancer. In conclusion, tumors with high HRD score exhibit an immune-sensitive TME. The HRD-high genotype is a promising marker for identifying ICI therapy responders among breast cancer patients.

Choosing Between Mastectomy and Breast-Conserving Therapy: Is Patient Distress an Influencing Factor?

BACKGROUND

Breast-conserving therapy (BCT) offers oncologic outcomes similar to those of mastectomy, yet many patients, when provided the option, choose mastectomy. This study aimed to evaluate the relationship between patient-reported distress and surgical decisions and to determine factors predictive of choosing BCT versus mastectomy.

METHODS

Patients with newly diagnosed breast cancer deemed candidates for BCT who completed a distress screen at their initial visit to an academic institution between 2016 and 2019 were retrospectively reviewed. This screening tool captures distress in emotional, social, health, and practical domains on a scale of 0 to 10. The distress scores were compared against surgical decisions using nonparametric Wilcoxon rank-sum tests. Patient factors associated with surgical choice were analyzed using chi-square, Fisher's exact, and Student's t tests. A two-sided p value lower than 0.05 was considered significant.

RESULTS

Of 506 patients deemed eligible for BCT, 430 (85%) chose BCT and 76 (15%) pursued mastectomy. The distress levels did not differ significantly between the surgical options. The patients who underwent mastectomy were on the average younger (50.7 vs 60.4 years; p < 0.0001), presented with palpable masses (p < 0.0001), had stage 0, 2, or 3 versus stage 1 disease (p < 0.0001), sought consultation for second opinions (19.7% vs 8.6%; p = 0.0032), received neoadjuvant chemotherapy (31.6% vs 16.3%; p = 0.0016), or had deleterious gene mutations (21.1% vs 5.1%; p < 0.0001).

CONCLUSIONS

Distress was not associated with the pursuit of surgical treatment. Rather, younger age, search for a second opinion, and a palpable mass present at presentation were associated with more aggressive surgical decisions. Understanding factors that influence surgical decision-making is critical in guiding informed decisions that reflect patient values.

Approaching Neoadjuvant Therapy in the Management of Early-Stage Breast Cancer

Neoadjuvant therapy is integral to the treatment of early-stage breast cancer. Goals of treatment include surgical downstaging of the tumor, rendering inoperable tumors resectable, and de-escalating axillary surgery in those with clinically positive nodes. Additionally, response to treatment provides important prognostic information regarding risk of recurrence and guides future adjuvant treatment. Although chemotherapy serves as the backbone of neoadjuvant treatment, an increased understanding of the tumor's clinical course as well as its molecular and genetic make-up aids in individualizing treatment and developing novel agents. This review summarizes current clinical approaches and the future direction to the management of breast cancer patients in the neoadjuvant setting.

Case Report: A 3D-Printed Surgical Guide for Breast-Conserving Surgery After Neoadjuvant Chemotherapy

Background

A challenging problem for patients undergoing breast-conserving surgery after neoadjuvant chemotherapy (NACT) is the accuracy of preoperative tumor localization. After chemotherapy, the original tumor is likely to shrink or scatter dramatically or even show complete remission. For breast-conserving surgery, the development of a guidance device to accurately estimate the resection area is imperative.

Case Presentation

We produced a three-dimensional (3D)-printed breast surgical guide (BSG) based on prone and supine magnetic resonance imaging (MRI). This device was tested on a patient who underwent breast-conserving surgery after NACT. Both ultrasonography and MRI revealed that the tumor shrank substantially after NACT. Identifying the target tumor area using pre-NACT MRI was feasible, and the tumor was safely removed with clear resection margins.

Conclusion

The BSG has several advantages over conventional methods for tumor localization after NACT. In particular, the BSG provided precise quantitative MRI information about the tumor area.

Margin Assessment and Re-excision Rates for Patients Who Have Neoadjuvant Chemotherapy and Breast-Conserving Surgery

BACKGROUND

Neoadjuvant chemotherapy (NAC) has enabled more patients to be eligible for breast-conservation surgery (BCS). Achieving negative lumpectomy margins, however, is challenging due to changes in tissue composition and potentially scattered residual carcinoma in the tumor bed. Data regarding BCS after NAC have shown variable re-excision rates. MarginProbe (Dilon Technologies, Newport News, VA, USA) has been shown to identify positive resection margins intraoperatively and to reduce the number of re-excisions in primary BCS, but has not been studied in NAC+BCS cases. This study aimed to investigate the clinicopathologic characteristics, margin status, and re-excision rates for NAC+BCS patients with and without the use of MarginProbe.

METHODS

The Institutional Breast Cancer Database was queried for patients who received NAC and had BCS from 2010 to 2019. The variables of interest were demographics, tumor characteristics, pathologic complete response (pCR), MarginProbe use, and re-excision rates.

RESULTS

The study population consisted of 214 patients who had NAC, 61 (28.5 %) of whom had NAC+BCS. The median age of the patients was 53.5 years. A pCR was achieved for 19 of the patients (31.1 %). Of the remaining 42 patients, 9 (21 %) had close or positive margins that required re-excision. Re-excision was associated with a larger residual tumor size (p = 0.025) and estrogen receptor (ER)-positive disease before NAC (p = 0.041). MarginProbe use was associated with a lower re-excision rate for the patients who had NAC+BCS (6 % vs. 31 %, respectively).

CONCLUSION

The patients with a larger residual tumor burden and ER-positive disease had a greater risk for inadequate margins at surgery. MarginProbe use was associated with a lower re-excision rate. Techniques to reduce the need for re-excision will support the use of BCS after NAC.

Breast-Conserving Surgery after Neoadjuvant Chemotherapy Using a Three-Dimensional-Printed Surgical Guide Based on Supine Magnetic Resonance Imaging: A Case Report

Tumor localization in patients receiving neoadjuvant chemotherapy (NACT) is challenging because substantial therapeutic remission of the original tumor after NACT is often noted. Currently, there is no guidance device that allows for an accurate estimation of the resection range in breast-conserving surgery after NACT. To increase the accuracy of tumor resection, we used a 3-dimensional-printed breast surgical guide based on magnetic resonance imaging (MRI) in the supine position for a breast cancer patient who underwent breast-conserving surgery after NACT. Using this device, the breast tumor with apparent therapeutic changes after NACT on imaging was successfully removed with clear resection margins by identifying the original tumor site in the affected breast. Irrespective of whether the residual tumor area after NACT is well defined, it is possible to confirm and target the tumor area on pre-NACT MRI using this device.

Local and regional therapy considerations after preoperative therapy in patients with breast cancer

PURPOSE OF REVIEW

The starting point of neoadjuvant therapy was to use preoperative chemotherapy in order to provide surgeons and radiotherapists with the possibility of local treatment in patients with locally advanced, primary inoperable or inflammatory disease. Since then, this treatment approach has dramatically evolved and is now a standard of care in patients with high-risk early breast cancer.

RECENT FINDINGS

The role of surgery after neoadjuvant therapy is to remove residual disease in the breast and or in the lymph nodes and to provide further treatment possibilities according to pathohistologic findings at surgery.

SUMMARY

Innovative medical treatments are now being used for neoadjuvant treatment in order to reduce the extent of locoregional surgery in the breast and the axilla and also to adjust further medical treatment after neoadjuvant therapy and surgery.

Neoadjuvant Chemotherapy, Endocrine Therapy, and Targeted Therapy for Breast Cancer: ASCO Guideline

PURPOSE

To develop guideline recommendations concerning optimal neoadjuvant therapy for breast cancer.

METHODS

ASCO convened an Expert Panel to conduct a systematic review of the literature on neoadjuvant therapy for breast cancer and provide recommended care options.

RESULTS

A total of 41 articles met eligibility criteria and form the evidentiary basis for the guideline recommendations.

RECOMMENDATIONS

Patients undergoing neoadjuvant therapy should be managed by a multidisciplinary care team. Appropriate candidates for neoadjuvant therapy include patients with inflammatory breast cancer and those in whom residual disease may prompt a change in therapy. Neoadjuvant therapy can also be used to reduce the extent of local therapy or reduce delays in initiating therapy. Although tumor histology, grade, stage, and estrogen, progesterone, and human epidermal growth factor receptor 2 (HER2) expression should routinely be used to guide clinical decisions, there is insufficient evidence to support the use of other markers or genomic profiles. Patients with triple-negative breast cancer (TNBC) who have clinically node-positive and/or at least T1c disease should be offered an anthracycline- and taxane-containing regimen; those with cT1a or cT1bN0 TNBC should not routinely be offered neoadjuvant therapy. Carboplatin may be offered to patients with TNBC to increase pathologic complete response. There is currently insufficient evidence to support adding immune checkpoint inhibitors to standard chemotherapy. In patients with hormone receptor (HR)-positive (HR-positive), HER2-negative tumors, neoadjuvant chemotherapy can be used when a treatment decision can be made without surgical information. Among postmenopausal patients with HR-positive, HER2-negative disease, hormone therapy can be used to downstage disease. Patients with node-positive or high-risk node-negative, HER2-positive disease should be offered neoadjuvant therapy in combination with anti-HER2-positive therapy. Patients with T1aN0 and T1bN0, HER2-positive disease should not be routinely offered neoadjuvant therapy.Additional information is available at www.asco.org/breast-cancer-guidelines.

Breast conservation and axillary management after primary systemic therapy in patients with early-stage breast cancer: the Lucerne toolbox

Primary systemic therapy is increasingly used in the treatment of patients with early-stage breast cancer, but few guidelines specifically address optimal locoregional therapies. Therefore, we established an international consortium to discuss clinical evidence and to provide expert advice on technical management of patients with early-stage breast cancer. The steering committee prepared six working packages to address all major clinical questions from diagnosis to surgery. During a consensus meeting that included members from European scientific oncology societies, clinical trial groups, and patient advocates, statements were discussed and voted on. A consensus was reached in 42% of statements, a majority in 38%, and no decision in 21%. Based on these findings, the panel developed clinical guidance recommendations and a toolbox to overcome many clinical and technical requirements associated with the diagnosis, response assessment, surgical planning, and surgery of patients with early-stage breast cancer. This guidance could convince clinicians and patients of the major clinical advancements purported by primary systemic therapy, the use of less extensive and more targeted surgery to improve the lives of patients with breast cancer.

A Decision-Making Supporting Prediction Method for Breast Cancer Neoadjuvant Chemotherapy

Neoadjuvant chemotherapy (NAC) may increase the resection rate of breast cancer and shows promising effects on patient prognosis. It has become a necessary treatment choice and is widely used in the clinical setting. Benefitting from the clinical information obtained during NAC treatment, computational methods can improve decision-making by evaluating and predicting treatment responses using a multidisciplinary approach, as there are no uniformly accepted protocols for all institutions for adopting different treatment regiments. In this study, 166 Chinese breast cancer cases were collected from patients who received NAC treatment at the First Bethune Hospital of Jilin University. The Miller–Payne grading system was used to evaluate the treatment response. Four machine learning multiple classifiers were constructed to predict the treatment response against the 26 features extracted from the patients’ clinical data, including Random Forest (RF) model, Convolution Neural Network (CNN) model, Support Vector Machine (SVM) model, and Logistic Regression (LR) model, where the RF model achieved the best performance using our data. To allow a more general application, the models were reconstructed using only six selected features, and the RF model achieved the highest performance with 54.26% accuracy. This work can efficiently guide optimal treatment planning for breast cancer patients.

Local Treatment of Triple-Negative Breast Cancer

ABSTRACT

Triple-negative breast cancer, compared with other molecular subtypes, poses particular challenges for optimizing the timing and the extent of locoregional treatments. In the past, the combination of increased rates of both locoregional and distant recurrences led to a preference of radical surgery and extensive radiation therapy; however, since the introduction of more effective chemotherapy, a sharp de-escalation in the extent of locoregional treatments followed. Current evidence confirms that less aggressive surgery in combination with tailored radiation therapy offers improved oncological outcomes combined with better quality of life. However, further research is required to optimize locoregional treatments, considering the significant heterogeneity in biological behavior and tumor response to systemic treatments.

The impact of neoadjuvant systemic therapy on breast conservation rates in patients with HER2-positive breast cancer: Surgical results from a phase II randomized controlled trial

BACKGROUND

Neoadjuvant systemic therapy (NST) induces tumor shrinkage and boosts the chance of breast-conserving thearpy (BCT) in patients with breast cancer. However, only a few trials have evaluated the effect of NST in conversion from BCT ineligibility to BCT eligibility in HER2-positive breast cancer.

METHODS

We conducted the surgical sub-study of a phase II randomized trial, which compared standard neoadjuvant treatment or an experimental treatment modified according to the interim Ki-67 evaluation in women with stage II or III HER2-positive breast cancer. The treating surgeons assessed eligibility for BCT before and after NST. We evaluated the change in BCT eligibility following NST. We also analyzed the type of surgery performed and the success rate of BCT.

RESULTS

Two hundred six patients were included in this study. Of these, 44.0% were considered BCT candidates at baseline, while 69.8% were deemed eligible for BCT after NST (P < 0.001). Among non-BCT candidates at baseline, 46% successfully converted to BCT candidates. Of 139 patients deemed eligible for BCT following NST, 84.2% attempted BCT, and successful BCT, defined as tumor-free at all surgical margins, was achieved in 96.8% of patients. Different treatment arms did not affect the rate of post-NST BCT eligibility (70.0% vs 69.7%).

CONCLUSIONS

This study demonstrated that NST resulted in an absolute increase of 25.8% in the rate of BCT eligibility in HER2-positive breast cancer. About a half of non-BCT candidates converted to BCT candidates. BCT was successful in most patients who attempted BCT. There were still patients who chose mastectomy even though they were deemed eligible for BCT. Patients considered BCT-ineligible due to large tumor size most likely converted to BCT-eligible with NST. On the other hand, NST had less impact on the surgical indication of patients with multicentric disease or probable poor cosmetic outcome.

Leveraging the increased rates of pathologic complete response after neoadjuvant treatment in breast cancer to de-escalate surgical treatments

INTRODUCTION

Breast conservative surgery (BCS) and sentinel lymph node biopsy (SLNB) after neoadjuvant treatment (NAT) is safe and effective for selected patients. This aim of this study is to evaluate the impact of anatomic site of response on outcomes and to assess the real population who may benefit from nonsurgical approaches after NAT.

MATERIAL AND METHODS

From a prospectively maintained database, patients with T1-4 N0-2 breast cancer undergoing NAT were identified. Clinicopathological and survival rates were compared in relation to response and anatomic site of response.

RESULTS

Six hundred and forty-six patients were included in the study. Pathologic complete response (pCR) was an independent factor for BCS and SLN. HER2 positive and TN tumors with cN0 achieving a breast pCR remain ypN0 (p = .002). Residual axillary disease was associated with breast residual tumor (p = .05) and subtype (p = .001). With a median follow up of 35.25 months, patients with any pCR had improved survival when compared with partial response, but not significant differences between pCR, axillary pCR, or breast pCR.

CONCLUSION

Achieving a pCR increases BCS and SLN. In selected subgroups, sparing any axillary surgery after NAT maybe feasible. In cN+ patients, any pCR was associated with survival, but not the anatomic site of response.

How Often Does Modern Neoadjuvant Chemotherapy Downstage Patients to Breast-Conserving Surgery?

BACKGROUND

Neoadjuvant chemotherapy (NAC) has been proven to increase breast-conserving surgery (BCS) rates, but data are limited on conversion rates from BCS-ineligible (BCSi) to BCS-eligible (BCSe), specifically, in patients with large tumors.

METHODS

Consecutive patients with stage I-III breast cancer treated with NAC from November 2013 to March 2019 were identified. BCS eligibility before and after NAC was prospectively determined. Patients deemed BCSi before NAC due to large tumor size were studied. Statistical analyses were conducted using Student's t-test, Wilcoxon rank sum test, Chi-square test, Fisher's test, and logistic regression.

RESULTS

In this study, 600 of 1353 cancers were BCSi with large tumors; 69% were non-BCS candidates, 31% were borderline-BCS (bBCS) candidates. Of non-BCS candidates, 69% became BCSe after NAC; 66% chose BCS, and 90% were successful. Among bBCS candidates, 87% were BCSe after NAC, 73% chose BCS, and 96% were successful. On univariate analysis, bBCS candidacy, lower cT stage, cN0 status, absence of calcifications, human epidermal growth factor receptor 2 positive (HER2+)/triple negative (TN) receptor status, poor differentiation, ductal histology, and breast pCR were associated with conversion to BCS eligibility. On multivariable analysis, receptor status (hormone receptor positive [HR+]/HER2- ref; odds ratio [OR] HER2+ 1.63, P = 0.047; HR-/HER2- OR, 2.26, P = 0.003) and breast pCR (OR 2.62, P < 0.001) predicted successful downstaging, while larger clinical tumor size (OR 0.86, P = 0.003), non-BCS candidacy (OR 0.46, P = 0.003), cN+ status (OR 0.54, P = 0.008), and calcifications (OR 0.56, P = 0.007) predicted lower downstaging rates.

CONCLUSION

In patients with large tumors precluding BCS, conversion to BCS eligibility was high with NAC, particularly in bBCS candidates. HER2+/TN receptor status predicted successful downstaging, while lower downstaging rates were observed with larger tumors, cN+ status, and calcifications. These factors should be considered when selecting patients for NAC.

PARP Inhibitors in the Treatment of Early Breast Cancer: The Step Beyond?

Exquisitely exploiting defects in homologous recombination process, poly(ADP-ribose) polymerase (PARP) inhibitors have recently emerged as a promising class of therapeutics in human epidermal growth factor receptor 2 (HER2)-negative advanced breast cancer with germline breast cancer 1 (BRCA1) or breast cancer 2 (BRCA2) mutations (gBRCA1/2m). In this setting, PARP inhibitors, either as single agent or in combination with platinum-based chemotherapy, significantly increased progression-free survival, as compared to conventional chemotherapy. Accordingly, further therapeutic advances are expected at an earlier stage of the disease. In the neoadjuvant setting, veliparib failed to increase the pathological complete response rate when added to a carboplatin-based regimen, in unselected triple-negative breast cancer patients. Similarly, when administered before anthracycline-cyclophosphamide, the neoadjuvant olaparib-paclitaxel combination was not superior to carboplatin–paclitaxel, in patients with HER2-negative breast cancer and BRCA1/2 mutation, or homologous recombination defect. Yet, neoadjuvant talazoparib, administered as a single-agent in patients with HER2-negative breast cancer and germline BRCA1/2 mutation, achieved an impressive pathological complete response rate of nearly 50%. In the adjuvant setting, the results from the OlympiA phase III study, evaluating adjuvant olaparib in HER2-negative early breast cancer and germline BRCA1/2 mutations, are eagerly awaited. Ongoing trials should clarify whether PARP inhibitors might improve outcome when administered in the adjuvant or neoadjuvant setting in early breast cancer patients with BRCA1/2 mutation or homologous recombination defect.

Is breast conserving therapy better than mastectomy? Surgeons must speak out

Several population-based studies suggest that breast conserving surgery followed by radiotherapy (BCT) may provide longer overall survival than mastectomy. Better locoregional control after BCT due to improvements of preoperative imaging, oncoplastic surgery and radiotherapy, as well as the recent trend towards surgical de-escalation may be involved. Alternatively, modern radiotherapy may have such an improved benefit/risk ratio that its survival advantage now stands out more clearly. However, since the therapeutic equivalence of BCT and mastectomy was demonstrated by several randomised trials, this information cannot be disregarded, nor radiotherapy should be used to compensate for inadequate surgery. Both BCT and mastectomy are likely here to stay as clinical presentation of breast cancer is highly variable, and women desires may transcend a rational balance of pros and cons between the two surgical approaches. Our duty as surgeons is to lead the multidisciplinary board and accompany the patients along this difficult decision-making process.