Marina De Brot MD PhD

Pathologist/Professor @acccancercenter. Secretary @TheISBP. VP @SBPatologia. Former Fellow @Sloan_Kettering, @institut_curie and Breast Path Fellow @UofT

[Marina De Brot MD PhD @DebrotMarina]

Happy news! So honored to be a part of this group #BreastPath #ISBP

[Paolo Tarantino @PTarantinoMD]

Over the next years, we will keep seeing multiple ADCs, with variable targets, showing high efficacy for MBC

The two features that these ADCs will always have in common:
- TOP1 payload
- only a handful or no TOP1-ADC pretreated patients in the trial

Can we get out of this loop?

[Aya Mohamed | MSc, MD 🎗 @Dr_Oncologista]

Premenopausal HR+/HER2− early breast cancer: young or high-risk should not automatically mean maximal therapy.

https://t.co/KWtpn6vB12

@OncoAlert #BreastCancer #bcsm @Annals_Oncology @myESMO

[ISBP @TheISBP]

Wrapping up @TheISBP WHO Updates at #USCAP2026 Companion Society Meeting is Dr. Cecily Quinn and updates on the “so-called” neuroendocrine tumors of the breast!

@TheUSCAP

[ISBP @TheISBP]

📣 BREAKING: The pink balloons have been benched…but the pink hydrangeas have entered the chat.

ISBP poster walks are happening with floral flair and zero helium violations. 🌺

Follow the hydrangeas, find the experts, join the fun. #USCAP2026 #BreastPath

[Marina De Brot MD PhD @DebrotMarina]

@TheISBP @TheUSCAP @HannahYWen @LuisBlancoJrMD Yay, looking good 🌸🩷🌸

[ISBP @TheISBP]

Come find the pink hydrangeas! Poster walk #1 starting now! #USCAP2026 @TheUSCAP @HannahYWen @LuisBlancoJrMD

[ISBP @TheISBP]

Congratulations to @DrKimAllison for being awarded the 2026 aISBP-BCRF Larry Norton MD Award!!!

@TheUSCAP #USCAP2026

[Luis Z. Blanco Jr., MD (he/him) 🔬🌈♥️ @LuisBlancoJrMD]

Excellent presentations and enlightening discussion with our expert panel and the audience at @TheISBP Companion Society Meeting at #USCAP2026!

[Dana-Farber’s Breast Oncology Center @DFCI_BreastOnc]

New @ESMO_Open 📰Imlunestrant plus abemaciclib versus fulvestrant plus abemaciclib in ER-positive, HER2-negative advanced #BreastCancer: an indirect treatment comparison of three phase III trials
🔓https://t.co/L9TFAuapZM
@jhaveri_komal @hoperugo @stolaney1

[Eman Magdy @EmanMagdy91D]

Angiomyolipoma: Key Diagnostic Features

Soft tissue pathology

#pathology

[Carmine Valenza @ValenzaCarmine]

⚠️Whether ESR1 interception or prevention, introducing oral SERDs earlier raises the question:
➡️ How does this affect the treatment trajectory?
❓The question should be “now or later?”, not “now or never.”
This requires uniform access to SERDs >1st L
- see our editorial
8/

[Abi Siva MD @AbiSivaMD]

To me, what’s most impressive about the VICTORIA-1 study is the significant improvement seen in a PIK3CA WT population, something we really haven’t seen before. Makes you wonder what the magnitude of benefit might look like in the mutation cohort when Arm 2 reads out. @oncodaily @OncBrothers #MedTwitter #bcsm

[Dana-Farber’s Breast Oncology Center @DFCI_BreastOnc]

Here's the #BreastCancer Research Digest-a summary of last week’s publications from select high-impact journals (February 27th - March 6th, 2026). #ClinicalResearch #CancerTreatment #BCSM #BreastCancerResearch

[ISBP @TheISBP]

Look for PINK BALLOONS & join @TheISBP experts for our Poster Walks! 💕

Prepare for wandering & wondering through the #BreastPathology posters.💡

Pathologists‑in‑Training, see you @TheUSCAP meeting in San Antonio — the countdown is on! ⏳

🎀 #USCAP2026

[Aya Mohamed | MSc, MD 🎗 @Dr_Oncologista]

Phase III DESTINY-Breast06
demonstrates consistent PFS benefit with T-DXd vs TPC in HR+/HER2-low and HER2-ultralow mBC after ≥1 prior ET.

HRs ranged 0.38–0.71, uniformly favoring T-DXd across subgroups.
https://t.co/jjNgHC4BeN

@OncoAlert #bcsm #BreastCancer

[Elisa Agostinetto @ElisaAgostinett]

T-DXd has revolutionized the treatment of HER+ breast cancer, yet predictive biomarkers are critically needed

An exploratory biomarker analysis of DestinyBreast trials is now out in @Annals_Oncology 👇🏻

@OncoAlert

[Yakup Ergün @dr_yakupergun]

Evidence is accumulating.

Consistent with our meta-analysis presented at #ESMO25, this retrospective cohort shows that first-line CDK4/6 + ET leads to shorter PFS in pathogenic BRCA1/2 and PALB2 carriers!

https://t.co/JDNkbdMXrd

[Open Medicine Insights @OpenMedInsights]

🚨 #BreastCancer | Biomarker-Driven Insight
🆕 Annals of Oncology – Article of the Month 🎧
📖 Full article: https://t.co/qQsBetMszz
Pooled analysis of T-DXd response & biomarkers
DESTINY-Breast01/02/03
@SaraTolaney @ShereneLoi @hoperugo
@PedramRazaviMD
@LoiSher
@giuseppecurigl1
@matteolambe
🔬 Trastuzumab deruxtecan (T-DXd) in HER2+ metastatic breast cancer
Key insights:

▫️ Deeper confirmed responses correlate with improved clinical outcomes
▫️ Biomarker analyses reinforce HER2 dependency
▫️ Consistent activity across prior lines of therapy
▫️ Supports response depth as a meaningful surrogate in ADC era

This pooled DESTINY analysis refines how we interpret response dynamics in HER2+ mBC — moving beyond ORR toward biologically contextualized benefit.

@Annals_Oncology
@tompowles1
#HER2 #BreastCancer #ADC #PrecisionOncology #OncologyResearch

[Yakup Ergün @dr_yakupergun]

Premenopausal HR+/HER2+ eBC – Adjuvant ET

• RD after NAT → OFS + AI
• pCR after NAT → risk-adapted
 – Stage III → OFS + AI
 – Stage I–II → AI or TAM ± OFS
• Upfront surgery → baseline stage-driven ET

Principle:
RD = ER-dependent, chemo-resistant → needs ET intensification

Great editorial👇

https://t.co/AuDXPhHDoi

[Sergio Cifuentes @Onco_Cifu88]

📄 Personalizing therapies over the course of hormone receptor–positive breast cancer
DOI: 10.3322/caac.70055

This review outlines the evolving treatment landscape of HR-positive breast cancer across disease stages, emphasizing dynamic therapeutic sequencing based on tumor biology, resistance mechanisms, and prior treatments.

🔬 Key biological concepts
• HR+ breast cancer is heterogeneous and evolves under treatment pressure
• Endocrine resistance arises via ESR1 mutations, PI3K/AKT/mTOR activation, CDK pathway dysregulation, and epigenetic changes
• Clonal evolution supports reassessment of biomarkers over time

🧪 Early-stage disease
• Adjuvant endocrine therapy remains the backbone
• CDK4/6 inhibitors (abemaciclib, ribociclib) improve invasive DFS in selected high-risk patients
• Germline BRCA status and emerging genomic tools may refine risk stratification

🧬 Metastatic setting
• First-line: endocrine therapy + CDK4/6 inhibitors is standard
• Subsequent lines incorporate:
– PI3K inhibitors (alpelisib) for PIK3CA-mutant tumors
– mTOR inhibition (everolimus)
– Oral SERDs for ESR1-mutant disease
• Treatment choice depends on prior exposure, mutational profile, and disease kinetics

🧠 Treatment sequencing
• No fixed algorithm; optimal sequencing remains an unmet need
• Serial molecular testing (tissue or ctDNA) supports therapy adaptation
• Avoidance of overtreatment and preservation of endocrine sensitivity are key goals

Q: This apply for us in LATAM? 🌎

@OncoAlert
@weoncologists
@benjiwal