This prospective real-world analysis shows slightly shorter median PFS and OS times compared with the pivotal trials. Patients in our analyses received alpelisib in later therapy lines, which may explain the poorer outcome.

P1/2, N=159, Not yet recruiting, Centro Di Riferimento Oncologico Di Aviano

In recent clinical trials of metastatic ER+ BC, next-generation SERDs demonstrated clinical activity, and elacestrant received an approval for advanced ESR1-mutant disease. NR tumors instead up-regulate multiple ERα-independent proliferative pathways, such as EGFR/MAPK and Hippo/TEAD, which may represent targetable dependencies in NR disease. Modeling resistance and lineage plasticity in vitro, we find that giredestrant-resistant ER+ BC cell lines exhibit profound shifts in chromatin accessibility, with the transcription factors, FOXA1 and FOXM1, implicated in gene expression of NR-upregulated proliferative pathways.

The patient had been receiving fulvestrant for known pulmonary metastasis diagnosed 14 years prior...Treatment with S-1 resulted in radiological improvement at four months. This case adds to the limited literature documenting OP-mimicking pulmonary metastasis from breast cancer and highlights the importance of maintaining a high index of suspicion and pursuing tissue diagnosis in patients with a history of breast cancer who present with new pulmonary infiltrates.

MONARCH-2 trial data are not generalisable to this real-world cohort, which had notably shorter OS, TFS and CFS that could not be explained by differences in measured patient characteristics.

In India, where patients with BC often present at advanced stages due to late diagnosis and limited access to targeted therapies, Palbociclib offers a well-tolerated and effective treatment option. Real-world data from Indian patients highlight its role in bridging treatment gaps, making personalized therapy more accessible, and aligning treatment strategies with global standards.

P1/2, N=5, Terminated, Criterium, Inc. | N=44 --> 5 | Recruiting --> Terminated; Study was terminated due to delayed recruitment.

P3, N=912, Recruiting, Shandong Suncadia Medicine Co., Ltd. | Not yet recruiting --> Recruiting | Initiation date: Dec 2026 --> Mar 2026

First-line aromatase inhibitors with CDK4/6 inhibitors enhance overall survival, while fulvestrant combinations benefit endocrine-resistant cases...Real-world data support these findings.ConclusionCDK4/6 inhibitors with endocrine therapy markedly improve survival in HR+/HER2- BC, yet ILC-focused trials and standardized reporting are limited. Future research should prioritize routine, centralized reporting of ILC subtypes to guide evidence-based, subtype-specific treatment strategies.

SIGNIFICANCE STATEMENT: Metabolite M14 of camizestrant (AZD9833), a major circulating metabolite in humans, was successfully identified as an N-glucuronide of an acid metabolite of camizestrant, and its unusual chromatographic and stability properties were characterized. The development of a novel hybrid chemical and biological synthesis for M14 has introduced a new approach to synthesizing glucuronides of compounds with acidic functional groups that otherwise interfere with their own in vitro glucuronidation.

The final analysis of the BRIGHT-2 randomized clinical trial confirms improved PFS with the addition of bireociclib to fulvestrant, with manageable safety as a treatment option for patients with HR-positive, ERBB2-negative ABC with progression after prior endocrine therapy. ClinicalTrials.gov Identifier: NCT05077449.

For triple-negative IBC, we demonstrated that neoadjuvant treatment does not benefit from addition of a PARP inhibitor, whereas for estrogen receptor-positive IBC, the combination of a CDK4/6 inhibitor and fulvestrant improved neoadjuvant treatment response. Our work provides a valuable resource of primary IBC models to study breast cancer biology and develop neoadjuvant treatments.