Breast and axillary surgery after neoadjuvant systemic treatment - A review of clinical routine recommendations and the latest clinical research

Axillary Surgery for Patients With Residual Isolated Tumor Cells (ypN0i+) After Neoadjuvant Systemic Therapy for Early Breast Cancer

The Oncology Grand Rounds series is designed to place original reports published in the Journal into clinical context. A case presentation is followed by a description of diagnostic and management challenges, a review of the relevant literature, and a summary of the authors' suggested management approaches. The goal of this series is to help readers better understand how to apply the results of key studies, including those published in Journal of Clinical Oncology, to patients seen in their own clinical practice.

Predicting axillary residual disease after neoadjuvant therapy in breast cancer using baseline MRI and ultrasound

OBJECTIVES

To predict axillary node residual disease in women treated for node-positive breast cancer (BC) by neoadjuvant therapy (NAT), using breast BI-RADS MRI features and axillary ultrasound at baseline.

MATERIAL AND METHODS

In this single-center, retrospective study, women with node-positive BC who underwent NAT between 2016 and 2021 were included. Pre-treatment axillary US and breast MRIs were evaluated using the BI-RADS lexicon and T2 features, including Breast Edema Score. Univariate and multivariate logistic regression analyses were conducted for the prediction of axillary residual disease (ARD). A multivariable model based on logistic regression was trained and evaluated on randomly split train and test sets (7:3 ratio).

RESULTS

Out of the 141 women, 41% had post-NAT ARD. Axillary metastasis was independently associated with luminal subtype (odds ratio (OR), 25.5; p < 0.001), anterior tumor location (OR, 14.1; p = 0.008), and cortical thickening ≥ 7 mm (OR, 6.09; p = 0.002). Intratumoral T2 high signal intensity was protective (OR, 0.16; p = 0.006), while Ki67 had a marginal association (p = 0.064). In the training and test sets, the model, which is available online, achieved AUCs of 0.860 (95% CI: 0.783-0.936) and 0.843 (95% CI: 0.714-0.971), respectively. Anterior depth location and cortical thickening greater than 7 mm were also independently associated with post-NAT axillary burden.

CONCLUSION

Adjusting for BC subtype and KI-67 index, the anterior third location of BC, a cortical thickness greater than 7 mm, and the absence of intratumoral T2 hyperintensity is predictive of ARD after NAT.

KEY POINTS

Question What baseline imaging-based predictive models can identify patients at risk of persistent nodal disease after neoadjuvant therapy? Findings Baseline US cortical thickness superior to 7 mm, anterior tumor location, and absence of an intratumoral high signal on T2-weighted MRI predict residual axillary disease. Clinical relevance Our predictive model, available online at: litoic.shinyapps.io/LNPred_Apps , including breast cancer subtype, Ki-67 index level, breast cancer location, intratumoral signal intensity on T2WI, and initial lymph node thickness, could guide post-NAT axillary management.

Surgical treatment after neoadjuvant systemic therapy for HER2-positive invasive breast cancer in the Netherlands: 10-Year trends and the influence an accompanying DCIS component

BACKGROUND

The presence of a DCIS component accompanying invasive breast cancer (IBC) is associated with a higher rate of primary mastectomy compared to IBC without DCIS. After neoadjuvant systemic therapy (NST), HER2+ IBC patients show high response rates, allowing for increasing breast-conserving surgery rates. The aim of this study was to examine surgical trends after NST in a Dutch nationwide HER2+ cohort, and the influence of a DCIS component on mastectomy rate.

METHODS

Women with HER2+ IBC, diagnosed between 2010 and 2019 and treated with NST and surgery were included from the Netherlands Cancer Registry. Mastectomy rate was examined over the years, and compared between patients with and without a DCIS component in the pre-NST biopsy. Multivariable logistic regression analysis was used to investigate the association of the DCIS component with mastectomy rate and likelihood of achieving ypT0.

RESULTS

In total, 5289 patients were included. Over 10 years, mastectomy rate significantly decreased from 62.6 % in 2010 to 35.1 % in 2019. Patients with IBC+DCIS more often underwent mastectomy, with a rate of 48.4 % in 2019, compared to 30.0 % in IBC only (p < 0.001). Percentage of ypT0 was significantly lower in patients with IBC+DCIS (38.7 %), compared to IBC only (47.3 %, p < 0.001) Multivariable logistic regression analyses showed presence of DCIS (OR 1.69, 95%CI 1.47-1.95, p < 0.001) to be independently associated with mastectomy.

CONCLUSION

Rate of mastectomy decreased significantly in HER2+ IBC treated with NST between 2010 and 2019. Presence of DCIS in the biopsy remained associated with higher mastectomy rate, yet 38.7 % of these patients do achieve ypT0.

Neoadjuvant chemotherapy for breast cancer in Italy: A Senonetwork analysis of 37,215 patients treated from 2017 to 2022

BACKGROUND

Adoption of neoadjuvant chemotherapy (NACT) in the "real world" has been poorly investigated. Aim of this study was to examine the rate of NACT in Italy, trends over time and determinants of therapeutic choices.

METHODS

Senonetwork, the recognized network of Breast Centers in Italy, has developed a voluntary national data warehouse with the aim to monitor and improve treatments quality. A retrospective analysis was conducted among 58,661 breast cancer (BC) patients treated between 2017 and 2022 by 24 high-volume Breast Centers participating in the project.

RESULTS

After subset exclusion, 37,215 primary BC patients were analysed, 32,933 underwent primary-breast-surgery and 4,282 underwent NACT. From 2017 to 2022, the overall NACT incidence increased particularly for HR-/HER2+, Triple-Negative, and HR+/HER2+ BC (p < 0.001). In cN + patients the recommendation to axillary lymph-node dissection after NACT decreased over time along with an increase of <4 lymph-nodes removed (p < 0.001). Immediate breast reconstruction and indication for nipple sparing mastectomy increased significantly over time (OR = 1.10, p = 0.011 and OR 1.14, p < 0.001, respectively). On multivariate analysis, there was a trend towards an increased adoption of conservative treatment for HR-/HER2+ (p = 0.01) and Triple Negative tumors (p = 0.06). Implementation of NACT varied significantly among Breast-Centers from 3.8 to 17.7 % (p < 0.001).

CONCLUSION

The impact of NACT on the subsequent surgical management is substantial and continues to evolve over time, resulting in less-extensive surgery. Even among high-volume Centers NACT implementation rate is still highly variable. Although we registered a significant increase in its use during the study period, these results need to be further improved.

Breast and axillary marking in the neoadjuvant setting: survey results from experts of the Brazilian society of mastology

Introduction/objectives

The precise location of the tumor site is essential for the success of surgical treatment. Neoadjuvant chemotherapy (NAC) is a challenge for preoperative tumor and node localization. Thus, the knowledge and attitudes of the affiliated members of the Brazilian Society of Mastology (SBM) regarding breast and axilla marking were evaluated and a consensus regarding management and treatment was reached.

Methods

This was an online survey conducted between June and December 2022. All 1,742 active mastologists affiliated to the SBM were invited anonymously. The online form contained 28 objective questions, of which 22 were formulated on a Likert scale. These questions addressed relevant aspects related to breast and axilla marking in the neoadjuvant setting. Responses that reached 70% agreement were considered consensual. Statistical analysis was performed using the SPSS program version 26.0. Post hoc analysis was performed when appropriate and the significance level was set at p < 0.05. Polychoric regression analyses were conducted using `VGAM` package.

Results

In total, 468 mastologists answered the questionnaire (26.8%), with a predominance of professionals aged between 40-49 years (32.1%). Most professionals were board-certified (84,8%). The indication of tumor marking in the breast prior to NAC was consensual (96.4%) and the metal clip was the preferred method (69.7%). There was no consensus regarding the indication of pre-NAC histologically positive lymph node marking (49.8% disagree and 42.8% agree). However, there was consensus that the clinical and imaging evaluation was insufficient for staging the axilla as N1 (71.6%). The contraindication of breast and node marking in T4b tumors (71.2%) was consensual. There was consensus on the indication of sentinel lymph node biopsy (SLNB) for initially cN1 (92.3%) or cN2 (72.7%) tumors that became cN0 after NAC, with 67.5% opting for dual staining with technetium and patent blue. When <3 lymph nodes were retrieved 41.0% of mastologists performed axillary lymphadenectomy. Among the 28 questions, consensus was reached on only 11 (39.3%).

Conclusion

The indication of pre-NAC breast marking is consensual among Brazilian mastologists, although axillary nodal marking is not. There is a great divergence of attitudes among Brazilian surgeons in relation to the many issues related to pre-NAC breast and axilla marking.

The Role of Level III Dissection in Locally Advanced Breast Cancer following Neoadjuvant Chemotherapy-A Prospective Study

Nisha Prasannan Breast cancer is the most common female cancer in India, with a significant number presenting as locally advanced breast cancer (LABC). Level III clearance is routinely performed in our institute in LABC following neoadjuvant chemotherapy (NACT). In our previous retrospective study, level III positivity rate was 15.5%. We aim to prospectively assess level III positivity rate in LABC patients post-NACT. This is a prospective study of female patients with LABC (defined as cT3N1-3M0 or cT4N0-3M0 or cT any N2,3M0) who received NACT and underwent surgery including level III dissection from November 2019 to October 2021. Data collected included age, menopausal status, TNM stage at presentation, grade, hormone receptor and HER2 status, treatment response, ycT and ycN stage, and final histopathology. Univariate and multivariate analysis was undertaken. p -Value less than or equal to 0.05 was considered significant. Study recruited 598 patients. Level III node positivity rate was 8.4%. The clinical complete response rate (cCR) was 36% (215/598). On univariate analysis, significant association was present between level III node and cCR ( p  < 0.01), ycT0 stage ( p  = 0.001), ycN0 stage ( p  = 0.028), level II node positivity ( p  = 0.001), ypT stage ( p  = 0.001), and ypN stage ( p  = 0.001). On multivariate analysis, significant association was present between level III node and ycT stage ( p  < 0.001), ypT stage ( p  = 0.001), and ypN stage ( p  = 0.001). Level III positivity rate in LABC post-NACT is high. In patients with advanced ycT stage, it would be advisable to offer complete axillary dissection including level III. Level III dissection may be avoided in patients with ycT0 or ycN0 or with cCR.

Is contrast-enhanced mammography (CEM) an alternative to MRI in assessing the response to primary systemic therapy of breast cancer?

PURPOSE

To evaluate the accuracy of contrast-enhanced mammography (CEM) and magnetic resonance imaging (MRI) in the assessing radiological response to primary systemic therapy (PST).

METHOD

Prospective study between February 2021 and October 2022. Women with breast cancer and indication of PST were enrolled. CEM and MRI were performed before and after PST, and the findings, including size and radiological response pattern, were compared with the size of the residual lesion measured in surgical specimens and its Miller-Payne classification (considered the gold standard). Two of four independent radiologists, with 2 years of CEM experience and 10 years of MRI experience, reviewed the images while being blinded to the results of the other technique. The agreement between measurements was evaluated using the Pearson correlation coefficient (r) and Lin's coefficient.

RESULTS

Forty-eight women with breast cancer who required PST were enrolled in the study, with a mean age of 57.21 ± 10.14 years. A total of thirty-three participants (68.75 %) completed the study. The correlation between CEM and MRI measurements was high before PST (r: 0.97), and local staging was identical for 45 out of 48 patients. MRI demonstrated better accuracy in predicting residual tumor size than CEM, with Lin's coefficient 0.91 and 0.73, respectively. However, no significant differences were observed in predicting response to therapy. Both methods tended to overestimate the size and degree of response in our study, with mean overestimations of 2.87 mm in CEM and 0.51 mm in MRI.

CONCLUSION

CEM was found to be as accurate as MRI in predicting response to PST, indicating its potential as an alternative imaging technique, but further research is necessary.

Prospective Pilot Study of 18F-Fluoroestradiol PET/CT in Patients With Invasive Lobular Carcinomas

BACKGROUND. PET/CT with 18F-fluoroestradiol (FES) (FDA-approved in 2020) depicts tissues expressing estrogen receptor (ER). Invasive lobular carcinoma (ILC) is commonly ER positive. OBJECTIVE. The primary aim of this study was to assess the frequency with which sites of histologically proven ILC have abnormal uptake on FES PET/CT. METHODS. This prospective single-center pilot study, conducted from December 2020 to August 2021, enrolled patients with histologically confirmed ILC to undergo FES PET/CT; patients optionally underwent FDG PET/CT. Two nuclear radiologists assessed FES PET/CT and FDG PET/CT studies for abnormal uptake corresponding to known ILC sites at enrollment and for additional sites of abnormal uptake, resolving differences by consensus. The primary endpoint was percentage of known ILC sites showing abnormal FES uptake. The alternative to the null hypothesis was that more than 60% of sites would have abnormal FES uptake, exceeding the percentage of ILC with abnormal FDG uptake described in prior literature. A sample size of 24 biopsied lesions was preselected to provide 81% power for the alternative hypothesis (one-sided α = .10). Findings on FES PET/CT and FDG PET/CT were summarized for additional secondary endpoints. RESULTS. The final analysis included 17 patients (mean age, 59.1 ± 13.2 years) with 25 sites of histologically confirmed ILC at enrollment (22 breast lesions, two axillary lymph nodes, one distant metastasis). FES PET/CT showed abnormal uptake in 22 of 25 (88%) lesions, sufficient to reject the null hypothesis (p = .002). Thirteen patients underwent FDG PET/CT. Four of 23 (17%) sites of histologically confirmed ILC, including additional sites detected and confirmed after enrollment, were identified with FES PET/CT only, and 1 of 23 (4%) was identified only with FDG PET/CT (p = .18). FES PET/CT depicted additional lesions not detected with standard-of-care evaluation in 4 of 17 (24%) patients (two contralateral breast cancers and two metastatic axillary lymph nodes, all with subsequent histologic confirmation). Use of FES PET/CT resulted in changes in clinical stage with respect to standard-of-care evaluation in 3 of 17 (18%) patients. CONCLUSION. The primary endpoint of the trial was met. The frequency of abnormal FES uptake among sites of histologically known ILC was found to be to be significantly greater than 60%. CLINICAL IMPACT. This pilot study shows a potential role of FES PET/CT in evaluation of patients with ILC. TRIAL REGISTRATION. ClinicalTrials.gov NCT04252859.

Neoadjuvant Therapy in Nonmetastatic Breast Cancer in Kurdistan, Iraq

PURPOSE

The core management of nonmetastatic breast cancer includes surgical tumor removal by either breast-conserving surgery (BCS) or mastectomy. The use of neoadjuvant chemotherapy (NACT) has shown the potential to downstage locally advanced breast cancer (LABC) and reduce the extent of breast or axillary surgery. This study aimed to assess the treatment approach for nonmetastatic breast cancer in the Kurdistan region of Iraq and to compare its alignment with the current international recommendations for cancer treatment.

METHODS

We retrospectively reviewed the records of 1,000 patients with prespecified eligible inclusion criteria who underwent either BCS or mastectomy for nonmetastatic invasive breast cancer at oncology centers in the Kurdistan region of Iraq between the period 2016 and 2021.

RESULTS

Of 1,000 patients (median age, 47 years [range, 22-85 years]), 60.2% underwent mastectomy and 39.8% underwent BCS. The proportion of patients treated with NACT has increased over time, with 8.3% of patients receiving neoadjuvant treatment in 2016 compared with 14.2% in 2021. Similarly, BCS increased from 36.3% in 2016 to 43.7% in 2021. Most patients who underwent BCS had early breast cancer with low nodal involvement burden.

CONCLUSION

The increasing trends of BCS practice in LABC along with the increased use of NACT in the Kurdistan region in recent years comply with international guidelines. Our large multicenter, real-life series emphasizes the need to implement and discuss more conservative surgical approaches, enhanced with the broader use of NACT, through education and information programs for health providers and patients, in the context of multidisciplinary team discussions, to deliver high-quality, patient-centric breast cancer care.

Breast surgery after neoadjuvant therapy

PURPOSE OF REVIEW

The standard of care in breast surgery has changed, from mastectomy to breast conserving surgery whenever possible, and from axillary dissection to sentinel node biopsy. Neoadjuvant systemic approaches have broadened the indications for organ-conserving and less mutilating surgery, but also raise important questions of balancing locoregional treatment de-escalation and protecting excellent long-term outcomes.

RECENT FINDINGS

Recent studies have aimed at investigating the safety of de-escalating surgical approaches not only in the upfront breast surgery situation but also after neoadjuvant systemic therapy. This pertains to both the safety of breast conserving surgery - including more complex oncoplastic approaches - within the new (posttherapeutic) anatomical extent of the residual disease, but more controversially to de-escalating surgical treatment of the axilla. While sentinel node biopsy appears to be the standard of care for node-negative disease also after primary systemic therapy, the optimal procedure in situations of posttherapeutic node-positive disease remains highly controversial.

SUMMARY

Both breast and axillary surgery after neoadjuvant systemic therapy for women with breast cancer has undergone multiple paradigm changes in recent years. For the primary tumor in the breast, breast-conserving surgery constitutes the standard of care, and unnecessary mastectomies should be strongly discouraged. For axillary surgery, sentinel-node biopsy should be aimed at, and completion axillary dissections minimized for situations of extensive disease and or poor neoadjuvant treatment response. Additional techniques such as targeted axillary dissection are currently under evaluation in clinical trials.