Impact of Imaging-Guided Localization on Performance of Tailored Axillary Surgery in Patients with Clinically Node-Positive Breast Cancer: Prospective Cohort Study Within TAXIS (OPBC-03, SAKK 23/16, IBCSG 57-18, ABCSG-53, GBG 101)

BACKGROUND

Tailored axillary surgery (TAS) is a novel surgical concept for clinical node-positive breast cancer. It consists of the removal of the sentinel lymph nodes (LNs), as well as palpably suspicious nodes. The TAS technique can be utilized in both the upfront and neoadjuvant chemotherapy (NACT) setting. This study assessed whether/how imaging-guided localization (IGL) influenced TAS.

PATIENTS AND METHODS

This was a prospective observational cohort study preplanned in the randomized phase-III OPBC-03/TAXIS trial. IGL was performed at the surgeon's discretion for targeted removal of LNs during TAS. Immediate back-up axillary lymph node dissection (ALND) followed TAS according to TAXIS randomization.

RESULTS

Five-hundred patients were included from 44 breast centers in six countries, 151 (30.2%) of whom underwent NACT. IGL was performed in 84.4% of all patients, with significant variation by country (77.6-100%, p < 0.001). No difference in the median number of removed (5 vs. 4, p = 0.3) and positive (2 vs. 2, p = 0.6) LNs by use of IGL was noted. The number of LNs removed during TAS with IGL remained stable over time (p = 0.8), but decreased significantly without IGL, from six (IQR 4-6) in 2019 to four (IQR 3-4) in 2022 (p = 0.015). An ALND was performed in 249 patients, removing another 12 (IQR 9-17) LNs, in which a median number of 1 (IQR 0-4) was positive. There was no significant difference in residual nodal disease after TAS with or without IGL (68.0% vs. 57.6%, p = 0.2).

CONCLUSIONS

IGL did not significantly change either the performance of TAS or the volume of residual nodal tumor burden.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03513614.

PI3K inhibition circumvents resistance to SHP2 blockade in metastatic triple-negative breast cancer

The protein tyrosine phosphatase SHP2 activates oncogenic pathways downstream of most receptor tyrosine kinases (RTK) and has been implicated in various cancer types, including the highly aggressive subtype of triple-negative breast cancer (TNBC). Although allosteric inhibitors of SHP2 have been developed and are currently being evaluated in clinical trials, neither the mechanisms of the resistance to these agents, nor the means to circumvent such resistance have been clearly defined. The PI3K signaling pathway is also hyperactivated in breast cancer and contributes to resistance to anticancer therapies. When PI3K is inhibited, resistance also develops for example via activation of RTKs. We therefore assessed the effect of targeting PI3K and SHP2 alone or in combination in preclinical models of metastatic TNBC. In addition to the beneficial inhibitory effects of SHP2 alone, dual PI3K/SHP2 treatment decreased primary tumor growth synergistically, blocked the formation of lung metastases, and increased survival in preclinical models. Mechanistically, transcriptome and phospho-proteome analyses revealed that resistance to SHP2 inhibition is mediated by PDGFRβ-evoked activation of PI3K signaling. Altogether, our data provide a rationale for co-targeting of SHP2 and PI3K in metastatic TNBC.

Abstract P2-14-08: Trends in neoadjuvant systemic therapy rates in Europe: Pre-planned substudy of TAXIS (OPBC-03, SAKK 23/16, IBCSG 57-18, ABCSG-53, GBG 101)

Introduction: Even though randomized controlled trials could not show a significant survival benefit for the use of neoadjuvant systemic therapy (NST), it is increasingly recommended for patients with clinically node-positive breast cancer due to its implications on prognosis, locoregional downstaging and response-driven adjuvant systemic therapy. The aim of this study was to assess the need for international standardization of treatment recommendations by evaluating clinical practice heterogeneity in use of 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) after randomization of the first 500 patients with clinically node-positive breast cancer who underwent axillary lymph node dissection (ALND) or axillary radiation (ART) without ALND after tailored axillary surgery (TAS) in the context of extended regional nodal irradiation. Clinically node-positive breast cancer was defined by confirmed nodal disease at the time of initial diagnosis; in case of neoadjuvant therapy, residual nodal disease was mandatory. Investigators were encouraged to enroll all eligible patients consecutively. However, TAXIS is unique inasmuch as its pragmatic design allows both the neoadjuvant and adjuvant setting according to the preferences of the treating physicians and institutions and thus provides an excellent opportunity to study patterns and trends in use of NST in patients with clinically positive nodes in Europe. Results: A total of 500 patients with a median age of 57 years (IQR: 48-69 years) were included at 44 breast centers in 6 European countries from August 2018 to June 2022. Subtype was hormone receptor (HR) positive (+) and human epidermal growth factor receptor 2 (HER2) negative (-) in 393 (80.0%), HR+/HER2+ in 52 (10.6%), HR-/HER2+ in 5 (1.0%) and HR-/HER2- in 34 (6.9%) patients. The rate of patients undergoing NST was 31.4% with a significant upward trend over time during the study period (from 20.0% in 2018 to 38.1% in 2022; p=0.044). The use of NST varied significantly by country (p=&lt; 0.001) and by site (p=0.015). For patients with clinical AJCC tumor stage II and III, the rates of patients undergoing NST in Switzerland were 26.5% (18 of 68) and 35.9% (92 of 256), in Germany 22.2% (2 of 9) and 30.4% (7 of 23), in Austria 50% (7 of 14) and 60% (9 of 15) and in Hungary 0% (0 of 15) and 20.7% (18 of 87), respectively (p=0.019 and 0.004). Large differences by country were found for ER+/HER2- breast cancer, ranging from 13.1% (11 of 84) in Hungary to 47.8% (11 of 23) in Austria (p=0.007). Within Switzerland, which was the country with most included patients (328 of 500) and participating sites (n=25), the rate of patients undergoing NST for ER+/HER2- breast cancer varied considerably by site, ranging from 10% (2 of 20) to 50% (11 of 22). Discussion: This study revealed substantial heterogeneity in clinical practice in Europe, indicating the need for development of and adherence to consistent guidelines to standardize the international use of NST.

Citation Format: Walter P. Weber, Zoltan Matrai, Stefanie Hayoz, Guido Henke, Daniel R. Zwahlen, Günther Gruber, Frank Zimmermann, Thomas Ruhstaller, Simone Muenst, Markus Ackerknecht, Christian Kurzeder, Sherko Küemmel, Vesna Bjelic-Radisic, Viktor Smanykó, Conny Vrieling, Rok Satler, Inna Meyer, Charles Becciolini, Susanne Bucher, Colin Simonson, Peter M. Fehr, Natalie Gabriel, Robert Maráz, Dimitri Sarlos, Konstantin J. Dedes, Cornelia Leo, Gilles Berclaz, Hisham Fansa, Christopher Hager, Klaus Reisenberger, Ákos Sávolt, Christian F. Singer, Roland Reitsamer, Jelena Winkler, Giang Thanh Lam Lam, Mathias K. Fehr, Tatiana Naydina, Magdalena Kohlik, Karine Clerc, Valerijus Ostapenko, Florian Fitzal, Martin Heidinger, Nadia Maggi, Alexandra Schulz, Pagona Markellou, Loïc Lelièvre, Daniel Egle, Jörg Heil, Michael Knauer, Christoph Tausch. Trends in neoadjuvant systemic therapy rates in Europe: Pre-planned substudy of TAXIS (OPBC-03, SAKK 23/16, IBCSG 57-18, ABCSG-53, GBG 101) [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P2-14-08.

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.

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Tailored axillary surgery is a novel concept for clinically node-positive breast cancer

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Tailored axillary surgery selectively removes positive lymph nodes

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Tailored axillary surgery is much less radical than axillary dissection

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Tailored axillary surgery removes the clipped node in the vast majority of patients

Abstract OT-04-03: Tailored axillary surgery with or without axillary lymph node dissection followed by radiotherapy in patients with clinically node-positive breast cancer (SAKK 23/16 / IBCSG 57-18 / ABCSG-53 / GBG 101 - TAXIS): A multicenter randomized phase III trial

Background Main weaknesses of neoadjuvant chemotherapy (NACT) to avoid axillary dissection (ALND) in patients with clinically node-positive breast cancer are frequent failure of achieving nodal pathologic complete response (pCR) and administration of chemotherapy even though not indicated otherwise in many cases. Tailored axillary surgery (TAS) was designed to selectively remove positive nodes and omit ALND in patients with clinically node-positive breast cancer either in the upfront surgery setting or in case of residual nodal disease after neoadjuvant therapy, which distinguishes this trial from all others ongoing and published. Trial design In this international, multi-center, phase-III, non-inferiority randomized controlled trial, including 61 study sites from six countries, we plan to randomize 1500 patients to either receive TAS followed by ALND and regional nodal irradiation excluding the dissected axilla, or receive TAS only followed by regional nodal irradiation including the full axilla. TAS consists of selective removal of the sentinel lymph nodes (SLNs) and all palpably suspicious findings, thereby tailoring the extent of axillary surgery to the extent of axillary disease, followed by specimen radiography to document removal of the clip placed in the sampled node. Imaging-guided localization is encouraged to increase the chances of clip removal. All patients undergo adjuvant whole-breast irradiation after breast conserving surgery and chest wall irradiation after mastectomy. Inclusion of internal mammary nodes is recommended irrespective of treatment arm. ClinicalTrials.gov Identifier: NCT03513614. Inclusion criteria - Clinically node-positive breast cancer (all molecular subtypes allowed) - Node-positivity palpable or detectable only by imaging at time of initial diagnosis - Newly diagnosed or isolated in-breast recurrence or second ipsilateral breast cancer after previous breast conserving surgery and sentinel procedure and at least 3 years disease free and no prior axillary dissection or axillary RT. - In case of prior neoadjuvant treatment: residual disease (including residual ITCs) confirmed by pathology at the time of surgery - Clipping of sampled axillary lymph node Exclusion criteria - Absence of clip in the specimen radiography - Palpable disease left behind in the axilla after TAS - No SLN identified in the axilla Specific aims To test the hypothesis that treatment with TAS and axillary radiotherapy is non-inferior to ALND in terms of disease-free survival (DFS) of clinically node-positive breast cancer patients. Secondary objective is to test if quality of life is significantly better with TAS and axillary radiotherapy compared to ALND. Statistical methods With type I error 5% and power 80%, 385 events will be needed to show non-inferiority of TAS and axillary RT in comparison to ALND with a non-inferiority hazard ratio (HR) of 1.289 (corresponding to a DFS at 5 years of 80% in the ALND arm and 75% in the TAS and axillary RT arm), including one interim analysis for efficacy/futility after 20% of the required events have occurred. The sample size needed is 1500 patients (750 per arm). The HR and one-sided 95% confidence interval will be calculated using a Cox regression model based on the per-protocol set. Present accrual and target accrual The trial was activated on 31 July 2018 and the first patient was randomized on 07 August 2018. As of 03 July 2020, 291 patients have been randomized. Accrual is currently running according to protocol and is planned until end of 2023 with the primary endpoint analysis expected in 2029. Contact information Prof. Dr. Walter Paul Weber, University Hospital Basel; Tel: +41 61 328 61 49; Walter.Weber@usb.ch

Citation Format: Walter Paul Weber, Guido Henke, Stefanie Hayoz, Karin Ribi, Stefanie Seiler, Charlotte Maddox, Thomas Ruhstaller, Daniel Rudolf Zwahlen, Simone Muenst, Markus Ackerknecht, Florian Fitzal, Mihály Újhelyi, Christian Kurzeder, Loïc Lelièvre, Christoph Tausch, Daniel Egle, Jörg Heil, Zoltan Matrai, Michael Knauer. Tailored axillary surgery with or without axillary lymph node dissection followed by radiotherapy in patients with clinically node-positive breast cancer (SAKK 23/16 / IBCSG 57-18 / ABCSG-53 / GBG 101 - TAXIS): A multicenter randomized phase III trial [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr OT-04-03.

Abstract PD4-04: Tailored axillary surgery to omit axillary lymph node dissection independently from the use of neoadjuvant chemotherapy in patients with clinically node-positive breast cancer: Pre-specified subproject within TAXIS (SAKK 23/16 / IBCSG 57-18 / ABCSG-53 / GBG 101)

Introduction: We developed tailored axillary surgery (TAS) to selectively remove positive nodes and omit axillary lymph node dissection (ALND) in patients with clinically node-positive breast cancer irrespective of the use of neoadjuvant chemotherapy. In this study, we evaluate the performance of this novel surgical concept that tailors the extent of axillary surgery to the extent of axillary disease. Methods: A prospective study was pre-specified to assess the performance of TAS in the international multicenter phase-III TAXIS trial randomizing patients with clinically node-positive breast cancer to undergo ALND or axillary radiation after TAS. TAS consists of selective removal of all palpably suspicious findings and the SLNs followed by specimen radiography to document removal of the clip placed in the sampled node. Imaging-guided localization is encouraged to increase the chances of clip removal. Only patients with confirmed nodal disease at the time of surgery can be randomized in TAXIS; the first 200 randomized patients were analyzed together with the ones achieving nodal pCR in this study. ClinicalTrials.gov Identifier: NCT03513614. Results: A total of 296 patients with a median age of 56.5 years (range: 25-88 years) were included at 28 breast centers from four European countries, 125 (42.3%) of whom underwent NACT and 75 (25.3%) of whom had nodal pCR. Subtype was hormone receptor (HR) positive (+) and human epidermal growth factor receptor 2 (HER2) negative (-) in 194 (65.5%), HR+/HER2+ in 40 (13.5%), HR-/HER2+ in 17 (5.7%) and HR-/HER2- in 39 (13.2%) patients. Breast-conserving surgery was performed in 178 patients (60%) and mastectomy in 117 (40%). Imaging-guided localization was attempted in 258 patients (87.2%) and was successful in 243 (82.1%). TAS removed a median of two (interquartile range [IQR] 0-3) palpably suspicious lesions and two (IQR 1-3) SLNs, thereby successfully removing the clip in 279 (94.3%) patients. There were no significant differences by use of imaging-guided localization (94.6% with vs 92.1% without, p=0.47) or type of clip (p=0.19), but a trend toward lower rate of clip removal after NACT (91.2% with vs 96.5% without NACT, p=0.075). Palpable disease was left behind after TAS in two (2.1%) patients and no SLN was detected in three (3.1%). In the 200 randomized patients with confirmed nodal disease at the time of surgery, lymph node metastases were palpable at the time of initial diagnosis in 102 (51%) patients and detectable only by imaging in 98 (49%). The median number of lymph nodes removed by TAS was four (IQR 2-8), two (IQR 1-4) of which were positive. Completion ALND following TAS removed additional positive nodes in 71 of 100 (71%) patients in the control group (20% with one additional node, 9% with 2, 8% with 3, 6% with 4, and 28% with &gt;4). The median number of additional lymph nodes removed by ALND was 14 (IQR 10-18), two (IQR 0-6) of which were positive. Of the 200 randomized patients, one in the TAS group received a radiotherapy boost and one in the ALND group returned to the operating room for residual suspicious findings on imaging. Discussion: The present results suggest that TAS has the potential to become the new axillary surgery standard in patients with clinically node-positive breast cancer. TAS was successfully performed in the vast majority of patients, with no further improvement by imaging-guided localization, which makes the procedure feasible at most breast centers. TAS selectively removed positive lymph nodes and was much less radical than ALND, but ALND removed additional positive nodes in more than two thirds of patients. Disease-free survival and quality of life will be assessed in the randomized trial.

Citation Format: Walter Paul Weber, Guido Henke, Stefanie Hayoz, Karin Ribi, Stefanie Seiler, Charlotte Maddox, Thomas Ruhstaller, Daniel Rudolf Zwahlen, Simone Muenst, Markus Ackerknecht, Florian Fitzal, Mihály Újhelyi, Christian Kurzeder, Loïc Lelièvre, Christoph Tausch, Daniel Egle, Jörg Heil, Zoltan Matrai, Michael Knauer. Tailored axillary surgery to omit axillary lymph node dissection independently from the use of neoadjuvant chemotherapy in patients with clinically node-positive breast cancer: Pre-specified subproject within TAXIS (SAKK 23/16 / IBCSG 57-18 / ABCSG-53 / GBG 101) [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PD4-04.

Tailored axillary surgery with or without axillary lymph node dissection followed by radiotherapy in patients with clinically node-positive breast cancer (TAXIS): study protocol for a multicenter, randomized phase-III trial

Background

Complete lymph node removal through conventional axillary dissection (ALND) has been standard treatment for breast cancer patients for almost a century. In the 1990s, however, and in parallel with the advent of the sentinel lymph node (SLN) procedure, ALND came under increasing scrutiny due to its association with significant patient morbidity. Several studies have since provided evidence to suggest omission of ALND, often in favor of axillary radiation, in selected clinically node-negative, SLN-positive patients, thus supporting the current trend in clinical practice. Clinically node-positive patients, by contrast, continue to undergo ALND in many cases, if only for the lack of studies re-assessing the indication for ALND in these patients. Hence, there is a need for a clinical trial to evaluate the optimal treatment for clinically node-positive breast cancer patients in terms of surgery and radiotherapy. The TAXIS trial is designed to fill this gap by examining in particular the value of tailored axillary surgery (TAS), a new technique for selectively removing positive lymph nodes.

Methods

In this international, multicenter, phase-III, non-inferiority, randomized controlled trial (RCT), including 34 study sites from four different countries, we plan to randomize 1500 patients to either receive TAS followed by ALND and regional nodal irradiation excluding the dissected axilla, or receive TAS followed by regional nodal irradiation including the full axilla. All patients undergo adjuvant whole-breast irradiation after breast-conserving surgery and chest-wall irradiation after mastectomy. The main objective of the trial is to test the hypothesis that treatment with TAS and axillary radiotherapy is non-inferior to ALND in terms of disease-free survival of clinically node-positive breast cancer patients in the era of effective systemic therapy and extended regional nodal irradiation. The trial was activated on 31 July 2018 and the first patient was randomized on 7 August 2018.

Discussion

Designed to test the hypothesis that TAS is non-inferior to ALND in terms of curing patients and preventing recurrences, yet is significantly superior in reducing patient morbidity, this trial may establish a new worldwide treatment standard in breast cancer surgery. If found to be non-inferior to standard treatment, TAS may significantly contribute to reduce morbidity in breast cancer patients by avoiding surgical overtreatment.

Trial registration

ClinicalTrials.gov, ID: NCT03513614. Registered on 1 May 2018.

www.kofam.ch, ID: NCT03513614. Registered on 17 June 2018.

EudraCT No.: 2018–000372-14.

Electronic supplementary material

The online version of this article (10.1186/s13063-018-3021-9) contains supplementary material, which is available to authorized users.

In vivo TCR Signaling in CD4(+) T Cells Imprints a Cell-Intrinsic, Transient Low-Motility Pattern Independent of Chemokine Receptor Expression Levels, or Microtubular Network, Integrin, and Protein Kinase C Activity

Intravital imaging has revealed that T cells change their migratory behavior during physiological activation inside lymphoid tissue. Yet, it remains less well investigated how the intrinsic migratory capacity of activated T cells is regulated by chemokine receptor levels or other regulatory elements. Here, we used an adjuvant-driven inflammation model to examine how motility patterns corresponded with CCR7, CXCR4, and CXCR5 expression levels on ovalbumin-specific DO11.10 CD4⁺ T cells in draining lymph nodes. We found that while CCR7 and CXCR4 surface levels remained essentially unaltered during the first 48–72 h after activation of CD4⁺ T cells, their in vitro chemokinetic and directed migratory capacity to the respective ligands, CCL19, CCL21, and CXCL12, was substantially reduced during this time window. Activated T cells recovered from this temporary decrease in motility on day 6 post immunization, coinciding with increased migration to the CXCR5 ligand CXCL13. The transiently impaired CD4⁺ T cell motility pattern correlated with increased LFA-1 expression and augmented phosphorylation of the microtubule regulator Stathmin on day 3 post immunization, yet neither microtubule destabilization nor integrin blocking could reverse TCR-imprinted unresponsiveness. Furthermore, protein kinase C (PKC) inhibition did not restore chemotactic activity, ruling out PKC-mediated receptor desensitization as mechanism for reduced migration in activated T cells. Thus, we identify a cell-intrinsic, chemokine receptor level-uncoupled decrease in motility in CD4⁺ T cells shortly after activation, coinciding with clonal expansion. The transiently reduced ability to react to chemokinetic and chemotactic stimuli may contribute to the sequestering of activated CD4⁺ T cells in reactive peripheral lymph nodes, allowing for integration of costimulatory signals required for full activation.