Benjamin Walbaum, Medical Oncologist at Pontifical Catholic University of Chile, shared a post on LinkedIn:
“Breast Cancer Newsletter | 23–30 Dec 2025
My weekly take.
1. CDK4/6i Reprograms the BC Immunopeptidome
Cell, 2025
CDK4/6i enhance MHC-I expression and diversify tumor antigens via RB-dependent chromatin remodeling.
- CDK4/6 inhibitors act as immune modulators, providing a strong biological rationale for combination with ICI
2. Adjuvant Chemotherapy Use After RxPONDER
JAMA Network Open, 2025
Chemotherapy use decreased in postmenopausal node-positive patients with low Recurrence Score, but remains high in premenopausal women.
- Genomic-guided de-escalation is advancing, but implementation gaps persist, especially in younger patients.
3. Datopotamab Deruxtecan vs Chemotherapy (TROPION-Breast01)
Annals of Oncology, 2025
No OS benefit despite PFS improvement; higher post-progression ADC use in the ChT arm.
- A clinically negative OS trial—Dato-DXd delays progression but does not clearly improve survival in real-world sequencing.
4. Axillary Dissection After NAC (microNAC)
The Lancet Oncology, 2025
ALND omission in ypNmi did not compromise outcomes overall, but increased axillary recurrence in TNBC.
- Axillary de-escalation is feasible in selected patients, not in TNBC.
5. Basal-Like HR+/HER2− BC
NPJ Breast Cancer, 2025
Basal-like HR+ tumors show high TILs and immune activation, resembling TNBC biology.
- Challenges classical HR+ categorization and identifies immune-rich subgroups for novel strategies.
6. Low-Dose Pembrolizumab in Early TNBC (PLANEt)
Annals of Oncology, 2025
Reduced-dose pembrolizumab achieved comparable pCR with less toxicity.
- Supports immunotherapy dose optimization, particularly relevant for resource-limited settings.
7. Oncotype DX: Biopsy vs Surgery
Journal of Clinical Oncology, 2025
High concordance overall; discordance mainly near decision thresholds.
- Core Biopsy-based testing is reliable, but caution is needed for borderline scores.
8. Antibiotic Use and Breast Cancer Survival
Nature Communications, 2025
No increased mortality with occasional antibiotics; frequent use associated with worse outcomes.
- Signals likely reflect comorbidity and infections rather than a causal microbiome effect.
9. ADC Target Expression in Metastatic Breast Cancer
Nature Communications, 2025
Marked heterogeneity of ADC targets across organs; frequent expression in normal tissues.
- Explains variable ADC efficacy and toxicity; static biomarkers are insufficient.
10. Everolimus After CDK4/6 Inhibitors
Breast Cancer Research, 2025
Reduced PFS and OS after prior CDK4/6i, with a small subgroup showing durable benefit.
- Everolimus remains an option, but reflects endocrine-resistant disease biology.
11. Gut Microbiome and Breast Cancer
Frontiers in Oncology, 2025
Enrichment of Bacteroides, Eggerthella, Blautia and depletion of Faecalibacterium converge on inflammation, reduced SCFAs, and estrogen reactivation.
- BC–associated dysbiosis is biologically coherent, linking diet, microbiota, and hormone-driven tumor biology.”
More posts featuring Benjamin Walbaum on OncoDaily.