HR positive

This case represents a rare report of surgical resection for breast cancer liver metastasis after CDK4/6 inhibitor-based therapy. It suggests that local treatment may be effective even in cases with suspected endocrine-resistant disease and provides practical insight into patient selection and treatment strategies, as the case fulfilled previously reported criteria for local therapy.

We consider ET suitability to be the clinical assessment of whether a patient could benefit from ET, where benefit is defined not solely by tumor response but by a clinically relevant constellation of characteristics and markers possibly predicting the durability of disease response and symptom control. Several unresolved questions remain regarding issues such as disease heterogeneity, optimal treatment sequencing, and biomarker precision, but further work and ongoing studies will help to support the evolution of guidelines and provide clarity around the effective application of this quickly developing field to daily clinical practice.

Immunotherapy showed substantial benefits in improving pCR rates in both TNBC and HR+HER2- patients when combined with neoadjuvant chemotherapy, especially in lymph node-positive breast cancer patients.

P=N/A, N=43, Not yet recruiting, KU Leuven

We review the current epidemiologic, mechanistic, and clinical evidence on how the gut microbiome influences TNBC biology, with particular attention to the tumor immune microenvironment and response to therapy. We highlight protective and pro-tumorigenic microbial signatures, the impact of antibiotics and obesity, and emerging strategies, such as dietary modulation and microbiome-targeted interventions, that may ultimately be used to optimize TNBC management and improve patient outcomes.

This study demonstrates that adjuvant abemaciclib+ET is being used at the labeled dosage in most Japanese patients. Furthermore, 2-year completion rates in patients with 2-year follow-up were comparable to the clinical trial data from monarchE (69%).

P=N/A, N=200, Active, not recruiting, Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins | Trial completion date: Jun 2026 --> Jun 2027

The majority of patients (72%) were treated in the first-line setting; 11 received ribociclib, 15 received palbociclib, and 3 received abemaciclib. Whether this translates into deferring disease progression requires randomized studies with larger treatment groups. To our knowledge, this study represents the first analysis evaluating 18F-FDG-PET/CT-guided SBRT in combination with CDK4/6 inhibitor-based therapy in patients with metastatic breast cancer.

Palbociclib, ribociclib, and abemaciclib, which are FDA-approved CDK4/6 inhibitors, constitute the standard first-line treatment for advanced hormone receptor-positive (HR+) breast cancers. Collectively, this study deepens the understanding of shared and drug-specific molecular characteristics and mechanisms of CDK4/6 inhibitors at multi-omic levels. Moreover, it provides an experimental basis and potential directions for customizing combination therapies based on pathway vulnerabilities, as well as exploration of novel therapeutic modes and drugs.

P1, N=90, Recruiting, Cogent Biosciences, Inc. | Not yet recruiting --> Recruiting | Initiation date: Feb 2026 --> Jun 2026

P=N/A, N=6150, Recruiting, iOMEDICO AG | Active, not recruiting --> Recruiting | Trial completion date: Apr 2029 --> Jun 2032 | Trial primary completion date: Apr 2029 --> Jun 2032

In this single-specimen controlled experiment, non-buffered formaldehyde preserved tissue biomarkers with small but measurable differences relative to neutral buffered formaldehyde for IHC analysis, although these findings require validation in multi-patient studies. Consistent with current guidelines, a cold ischemia time of up to 1 hour maintained adequate biomarker preservation. These preliminary results may be relevant for pathology laboratories in resource-limited settings where neutral buffered formalin may not be easily accessible, and warrant further investigation across diverse tumor types and baseline expression levels, particularly tumors with ER-low-positive (1-10%) or heterogeneous expression.