Role of immunosuppressive JNK pathway in the tumor microenvironment among TNBC subtypes in IBCSG trial 22-00.

Phosphorylation of the JNK (pJNK) protein promotes an immunosuppressive tumor microenvironment (TME), enhancing aggressiveness in inflammatory triple-negative breast cancer (TNBC). This study evaluated the role of JNK signaling using a gene signature. RNA sequencing was performed on 347 TNBC tumors from the phase 3 International Breast Cancer Study Group (IBCSG) 22-00 trial, which evaluated adjuvant low-dose cyclophosphamide and methotrexate (CM).

Invasive lobular carcinoma: Strategies and perspectives from the lobular breast cancer research group.

Invasive lobular carcinoma (ILC) represents approximately 10-15% of all breast cancers and is defined by a unique discohesive morphology due to loss of E-cadherin. Despite its prevalence, ILC has been historically underrepresented in clinical and translational research, contributing to diagnostic, therapeutic, and prognostic uncertainties. This narrative review, conducted by the Invasive Lobular Carcinoma Research Group, synthesizes current evidence on ILC with expert perspectives to inform future research and clinical strategies.

Hormonal factors predictive of fertility in patients with breast cancer interrupting adjuvant endocrine therapy to attempt pregnancy in POSITIVE trial.

Purpose: The POSITIVE trial showed that premenopausal women with breast cancer (BC) can safely pause adjuvant endocrine treatment (ET) to attempt conception. 74 % of patients conceived spontaneously or through assisted reproductive technology (ART); Investigating hormonal factors that predict fertility was a key secondary endpoint.

Methods: Hormonal factors were assessed in non-pregnant women at months 3, 6, and 12 after ET interruption.

Prognostic relation of body mass index on extended aromatase inhibition treatment in postmenopausal patients with estrogen receptor positive breast cancer: A retrospective analysis of the SOLE trial.

Background: Obesity is associated with a greater risk of developing distant recurrences in patients with estrogen receptor-positive (ER+) breast cancer. This association is however poorly investigated in patients treated with extended endocrine treatment (ET). We therefore evaluated the prognostic role of BMI in the SOLE trial, where postmenopausal patients, after having completed 4-6 years of adjuvant ET, were treated with 5 additional years of continuous or intermittent letrozole.

Determinants of response and molecular dynamics in HER2+ER+ breast cancers from the NA-PHER2 trial receiving HER2-targeted and endocrine therapies.

Improved outcomes in HER2+ female breast cancer have resulted from chemotherapy and anti-HER2 therapies. However, HER2+ER+ cancers exhibit lower response rates. The phase 2 NA-PHER2 trial (NCT02530424) investigated chemo-free preoperative HER2 blockade (trastuzumab + pertuzumab) and CDK4/6 inhibition (palbociclib) with or without endocrine therapy (fulvestrant) in HER2+ER+ breast cancer.

Genomic Characterization and Prognostic Significance of Human Epidermal Growth Factor Receptor 2-Low, Hormone Receptor-Positive, Early Breast Cancers From the BIG 1-98 and SOFT Clinical Trials.

Purpose: To investigate whether hormone receptor-positive, human epidermal growth factor receptor 2-low (HR+HER2-low) versus HR+HER2-zero early breast cancers have distinct genomic and clinical characteristics.

Methods: This study included HR+, HER2-negative early breast cancers from patients enrolled in the phase III, randomized BIG 1-98 and SOFT clinical trials that had undergone tumor genomic sequencing. Tumors were classified HR+HER2-low if they had a centrally reviewed HER2 immunohistochemistry (IHC) score of 1+ or 2+ with negative in situ hybridization and HR+HER2-zero if they had an HER2 IHC score of 0.

Metastasis-directed stereotactic radiotherapy and systemic treatment continuation for patients with oligoprogressive metastatic breast cancer.

Background: About 15-20 % of patients with metastatic breast cancer (mBC) can experience oligoprogressive disease (OPD) in ≤ 5 sites of disease. Patients with OPD may benefit from metastasis-directed stereotactic radiotherapy (SBRT) to all sites of cancer progression while maintaining the same systemic treatment, aiming to prolong the time to next systemic treatment (NEST). This study aims to assess the outcomes provided by this multimodal strategy.

Trastuzumab Duocarmazine in Pretreated Human Epidermal Growth Factor Receptor 2-Positive Advanced or Metastatic Breast Cancer: An Open-Label, Randomized, Phase III Trial (TULIP).

Purpose: Human epidermal growth factor receptor 2 (HER2)-targeted therapy is standard of care for HER2-positive (HER2+) breast cancer, but most patients develop progressive disease with persistent HER2 expression. No definitive treatment guidance currently exists beyond second line. Trastuzumab duocarmazine (T-Duo) is a third-generation, HER2-targeted antibody-drug conjugate that demonstrated efficacy and acceptable safety in phase I studies of heavily pretreated patients with HER2+/HER2-low breast cancer.

The Immune-Related 27-Gene Signature DetermaIO Predicts Response to Neoadjuvant Atezolizumab plus Chemotherapy in Triple-Negative Breast Cancer.

Purpose: We assessed the 27-gene RT-qPCR-based DetermaIO assay and the same score calculated from RNA sequencing (RNA-seq) data as predictors of sensitivity to immune checkpoint therapy in the neoTRIPaPDL1 randomized trial that compared neoadjuvant carboplatin/nab-paclitaxel chemotherapy (CT) plus atezolizumab with CT alone in stage II/III triple-negative breast cancer. We also assessed the predictive function of the immuno-oncology (IO) score in expression data of patients treated with pembrolizumab plus paclitaxel (N = 29) or CT alone (N = 56) in the I-SPY2 trial.

Experimental Design: RNA-seq data were obtained from pretreatment core biopsies from 242 (93.

Breast Cancer Index in Premenopausal Women With Early-Stage Hormone Receptor-Positive Breast Cancer.

Importance: Adjuvant ovarian function suppression (OFS) with oral endocrine therapy improves outcomes for premenopausal patients with hormone receptor-positive (HR+) breast cancer but adds adverse effects. A genomic biomarker for selecting patients most likely to benefit from OFS-based treatment is lacking.

Objective: To assess the predictive and prognostic performance of the Breast Cancer Index (BCI) for OFS benefit in premenopausal women with HR+ breast cancer.

HER2DX Genomic Assay in HER2-Positive Early Breast Cancer Treated with Trastuzumab and Pertuzumab: A Correlative Analysis from the PHERGain Phase II Trial.

Purpose: The purpose of this study was to assess the predictive capability of HER2DX assay following (neo)adjuvant trastuzumab-pertuzumab (HP)-based therapy in HER2-positive (HER2+) early breast cancer.

Experimental Design: HER2DX was analyzed in baseline pretreatment tumors from the PHERGain trial. Patients with stage I-IIIA HER2+ early breast cancer were randomized to group A [docetaxel, carboplatin, and HP (TCHP)] and group B (HP ± endocrine therapy).

3-year invasive disease-free survival with chemotherapy de-escalation using an F-FDG-PET-based, pathological complete response-adapted strategy in HER2-positive early breast cancer (PHERGain): a randomised, open-label, phase 2 trial.

Background: PHERGain was designed to assess the feasibility, safety, and efficacy of a chemotherapy-free treatment based on a dual human epidermal growth factor receptor 2 (HER2) blockade with trastuzumab and pertuzumab in patients with HER2-positive early breast cancer (EBC). It used an fluorine-fluorodeoxyglucose-PET-based, pathological complete response (pCR)-adapted strategy.

Methods: PHERGain was a randomised, open-label, phase 2 trial that took place in 45 hospitals in seven European countries.

Optimal [F]FDG PET/CT Cutoff for Pathologic Complete Response in HER2-Positive Early Breast Cancer Patients Treated with Neoadjuvant Trastuzumab and Pertuzumab in the PHERGain Trial.

The PHERGain trial investigated the potential of metabolic imaging to identify candidates for chemotherapy deescalation in human epidermal growth factor receptor 2 (HER2)-positive, invasive, operable breast cancer with at least 1 breast lesion evaluable by [F]FDG PET/CT. [F]FDG PET/CT responders were defined as patients with an SUV reduction (ΔSUV) of at least 40% in all of their target lesions after 2 cycles of trastuzumab and pertuzumab (HP) (with or without endocrine therapy). In total, 227 of 285 patients (80%) included in the HP arm showed a predefined metabolic response and received a total of 8 cycles of HP (with or without endocrine therapy).

Fine-Tuning Adjuvant Endocrine Therapy for Early-Stage Breast Cancer: An Expert Consensus on Open Issues for Future Research.

After decades of research, improving the efficacy of adjuvant endocrine therapy (ET) for early-stage breast cancer becomes increasingly difficult. Beyond technological breakthroughs and the availability of new classes of drugs, further improvement of adjuvant ET will require applying a rigorous research approach in poorly investigated areas. We critically discuss some key principles that should inform future research to improve ET efficacy, including identifying specific subgroups of patients who can benefit from escalating or de-escalating approaches, optimizing available and new treatment strategies for different clinical contexts, and dissecting the direct and indirect biological effects of therapeutic interventions.

Differential Benefit of Metronomic Chemotherapy Among Triple-Negative Breast Cancer Subtypes Treated in the IBCSG Trial 22-00.

Purpose: To explore whether specific triple-negative breast cancer (TNBC) molecular subtypes are predictive for a benefit from maintenance low-dose cyclophosphamide and methotrexate (CM) in the adjuvant IBCSG 22-00 phase III clinical trial.

Experimental Design: RNA sequencing was performed on a selection of 347 TNBC formalin-fixed paraffin-embedded (FFPE) tumor samples following a case-cohort-like sampling. TNBC subtypes were computed on gene expression data.

Spatial predictors of immunotherapy response in triple-negative breast cancer.

Immune checkpoint blockade (ICB) benefits some patients with triple-negative breast cancer, but what distinguishes responders from non-responders is unclear. Because ICB targets cell-cell interactions, we investigated the impact of multicellular spatial organization on response, and explored how ICB remodels the tumour microenvironment. We show that cell phenotype, activation state and spatial location are intimately linked, influence ICB effect and differ in sensitive versus resistant tumours early on-treatment.

Efficacy of Metronomic Oral Vinorelbine, Cyclophosphamide, and Capecitabine vs Weekly Intravenous Paclitaxel in Patients With Estrogen Receptor-Positive, ERBB2-Negative Metastatic Breast Cancer: Final Results From the Phase 2 METEORA-II Randomized Clinical Trial.

Importance: In spite of the effectiveness of endocrine therapy plus cyclin-dependent kinase (CDK) 4/6 inhibitors as the first-line treatment for estrogen receptor (ER)-positive, erb-b2 receptor tyrosine kinase 2 (ERBB2 [formerly HER2/neu])-negative (ER+/ERBB2-) metastatic breast cancer (MBC), patients eventually develop resistance, and eventually most will receive chemotherapy. The METEORA-II trial compared a metronomic all-oral treatment with intravenous (IV) chemotherapy.

Objective: To compare the efficacy of the oral vinorelbine plus cyclophosphamide plus capecitabine (VEX) regimen vs weekly IV paclitaxel among patients with ER+/ERBB2- MBC who are candidates for chemotherapy.

Interrupting Endocrine Therapy to Attempt Pregnancy after Breast Cancer.

Background: Prospective data on the risk of recurrence among women with hormone receptor-positive early breast cancer who temporarily discontinue endocrine therapy to attempt pregnancy are lacking.

Methods: We conducted a single-group trial in which we evaluated the temporary interruption of adjuvant endocrine therapy to attempt pregnancy in young women with previous breast cancer. Eligible women were 42 years of age or younger; had had stage I, II, or III disease; had received adjuvant endocrine therapy for 18 to 30 months; and desired pregnancy.

Serum thymidine kinase activity in patients with HR-positive/HER2-negative advanced breast cancer treated with ribociclib plus letrozole: Results from the prospective BioItaLEE trial.

Background: Thymidine kinase 1 (TK1) is an enzyme downstream of the CDK4/6 pathway, with a critical role in DNA synthesis; serum TK1 activity (sTKa) is a novel liquid biopsy biomarker of tumour cell proliferation.

Methods: The phase IIIb, BioItaLEE trial (NCT03439046) collected sera from postmenopausal patients with hormone receptor-positive (HR+), HER2-negative (HER2-) advanced breast cancer (ABC) treated with first-line ribociclib plus letrozole at baseline, day 15 of cycle 1 (C1D15), day 1 of cycle 2 (C2D1), and at first imaging. Associations between sTKa assessed at different time points or sTKa dynamic patterns, and progression-free survival (PFS) were evaluated using multivariate Cox models.

Tailoring the optimal duration of the extended adjuvant endocrine therapy in patients with early-stage breast cancer. A systematic review and meta-analysis of randomized clinical trials.

Background: Controversy exists regarding the optimal duration of the extended adjuvant endocrine treatment (ET) in patients with early-stage breast-cancer (eBC). We performed a systematic review and trial-level meta-analysis of all randomized clinical trials (RCTs) comparing a "limited-extended" adjuvant ET (defined as more than 5 but less than 7.5 years of treatment overall) versus a "full-extended" adjuvant ET (defined as more than 7.