Amy Andersen, MD

BRCA1 vs BRCA2 — simplified • BRCA1 → early, TNBC, ovarian risk ↑, aggressive • BRCA2 → HR+, broader cancers (prostate, pancreas) • Both → PARP sensitive Know the pattern → guide screening & therapy #MVOnco #BreastCancer #Oncology

A ready-to-go OPD algorithm for adjuvant chemo in HR+/HER2– early breast cancer. Clinical risk + tumor biology + Recurrence Score + age + menopausal status → clear, practical decisions. Avoid overtreatment. #BreastCancer #RecurrenceScore #OncotypeDX #PrecisionOncology

Immunotherapy and Targeted Therapy for Advanced Gastroesophageal Cancer: ASCO Guideline Update ascopubs.org/doi/10.1200/JC…

Algorithm of ET ± targeted treatment options after ET + CDK4/6 inhibitors. Some options are not yet approved— caution! From Dr. Alessandra Gennari’s excellent discussion at #ESMO25👇

This distinction is important: In HER2-positive mCRC, if a RAS mutation is present, T-DXd should be preferred. If RAS is wild-type, either T-DXd or other anti-HER2 agents can be used. Excellent summaries👇

HR+/HER2– metastatic breast cancer management is changing fast! In this piece👇 @elmayermd and I share our perspective on how targeted agents, oral SERDs, & molecularly informed sequencing are reshaping decision-making @DFCI_BreastOnc @OncoAlert

Interesting move in the new NCCN guidelines: ADCs are now listed as a first-line option in mTNBC, even before FDA approval. Highlights how rapidly the treatment landscape is evolving. #sabcs25 @ASCO @SABCSSanAntonio #MedTwitter @OncBrothers @TotalHealthConf @PTarantinoMD @drsarahsam

Schematic representation of MSI testing based on ESMO and ASCO recommendations

🚨 Gastric Cancer 2026 – Evidence That Should Change Practice The new JAMA Review (Jan 2026) pulls together the trials that now define modern gastric cancer care. Here is the trial-led snapshot every oncologist should know 👇 🌍 Why this matters Gastric cancer remains the 5th leading cause of cancer death worldwide, with most patients still presenting at advanced stages. Outcomes are now tightly linked to trial-backed biomarker selection. 🦠 Prevention evidence • Community H. pylori eradication trial (Pan et al., Nat Med 2024) showed significant long-term reduction in gastric cancer incidence. Prevention is still the most powerful intervention. 🔪 Perioperative and locally advanced disease • FLOT4 – Established perioperative FLOT as the global standard (OS 50 vs 35 months). • MATTERHORN – FLOT + durvalumab improved 2-year event-free survival (67.4% vs 58.5%). • NEONIPIGA – MSI-H/MMR-deficient tumors showed striking pCR rates with neoadjuvant ipilimumab + nivolumab, challenging chemotherapy altogether. 🧬 First-line metastatic disease – biomarker driven • CheckMate 649 – Nivolumab + chemo improved OS in PD-L1 CPS ≥5. • KEYNOTE-859 – Pembrolizumab + chemo improved OS across PD-L1 strata. • ToGA – Trastuzumab + chemo established HER2-positive standard. • KEYNOTE-811 – Pembrolizumab + trastuzumab + chemo pushed median OS beyond 20 months in HER2+ disease. • SPOTLIGHT & GLOW – Zolbetuximab + chemo improved OS and PFS in CLDN18.2-positive tumors. 🎯 Second-line and beyond • DESTINY-Gastric01 – Trastuzumab deruxtecan improved OS in HER2+ disease post progression. • RAINBOW – Ramucirumab + paclitaxel improved survival and quality of life. • TAGS – Trifluridine-tipiracil showed modest but real benefit in later lines. 🤝 Supportive care is evidence-based • Interdisciplinary supportive care trial – Early nutrition and psychosocial support improved OS by ~3 months, rivaling many systemic therapies. 📌 Take-home message Gastric cancer in 2026 is no longer chemo-first. It is trial-defined, biomarker-led, and multidisciplinary. Skipping biomarkers or evidence-based sequencing is no longer defensible. #OncoTwitter #MedTwitter #GastricCancer #GI26 @ASCO @ESMO_Open @OncoAlert @myESMO

🚨 New pooled safety data for T-DXd across DESTINY trials Largest safety analysis to date of trastuzumab deruxtecan (T-DXd) across doses and tumor types is out in The Oncologist 🧬 🔍 What was analyzed 9 phase I-III DESTINY trials N = 1,678 patients Breast, gastric, lung cancers Doses: 5.4 mg/kg vs 6.4 mg/kg Q3W 📊 Key safety signals •Most common TEAEs: nausea, fatigue, neutropenia •GI + hematologic toxicities dominate, mostly grade 1–2 •Dose modifications common, discontinuation relatively infrequent 🫁 ILD remains the key concern •Adjudicated ILD: ~11–12% overall •Grade ≥3 ILD: ~1.7–1.8% •ILD-related mortality: ~1% •Median onset: ~3–6 months → vigilance over time matters 👵 Who needs closer monitoring •Age ≥65 years •Renal impairment •Longer treatment duration 💊 Practice-changing nuance •NCCN now classifies T-DXd as highly emetogenic •Proactive triple antiemetic strategies likely needed upfront 🧠 Bottom line T-DXd toxicities are largely manageable, but require anticipation, early intervention, and structured monitoring, especially for ILD and nausea, to keep patients on this highly effective drug. #OncoTwitter #MedTwitter #BreastCancer #HER2 #ADC #Enhertu @DFCI_BreastOnc @stolaney1 @PTarantinoMD @OncoAlert @ASCO @myESMO @ESMO_Open

Why can’t 𝐩𝐚𝐜𝐥𝐢𝐭𝐚𝐱𝐞𝐥 run through plastic tubing? 🚫
Because 𝐂𝐫𝐞𝐦𝐨𝐩𝐡𝐨𝐫 𝐄𝐋 leaches 𝐃𝐄𝐇𝐏—an avoidable toxicity. 𝐃𝐫𝐮𝐠–𝐝𝐞𝐯𝐢𝐜𝐞 𝐢𝐧𝐭𝐞𝐫𝐚𝐜𝐭𝐢𝐨𝐧𝐬 𝐦𝐚𝐭𝐭𝐞𝐫. 🧠 #Paclitaxel #PatientSafety
#OncologyEducation #ExamPearls #MVOnco

Are All Aromatase Inhibitors Really the Same? A French nationwide cohort study just published in JAMA Network Open (n=148,436) challenges the clinical equivalence of the three main aromatase inhibitors (AIs) in postmenopausal HR+ early breast cancer. Here’s what they found in a decade of real-world data: 🔬 Exemestane underperformed compared to anastrozole and letrozole in both Disease-Free Survival (DFS) and Overall Survival (OS) at 8 years, even after adjusting for persistence. 📉 8-Year DFS (Natural persistence): - Exemestane: 79.1% - Anastrozole: 81.0% - Letrozole: 81.1% 📉 8-Year OS (Natural persistence): - Exemestane: 88.8% - Anastrozole: 90.5% - Letrozole: 89.9% More alarming: The difference persisted under a "perfect adherence" scenario, meaning it’s not just about patients stopping treatment—it seems to be a drug-specific effect. 🧠 Why might this happen? - Pharmacologic potency: Letrozole achieves more profound estrogen suppression. - Exemestane’s unique metabolism: Its androgenic metabolite may activate residual ER/AR pathways, potentially driving resistance. - Higher discontinuation rates with exemestane (39.3% at 5y vs ~35% for others), though not the sole explanation. 💡 Clinical takeaway for LATAM & global practice: We’ve long considered these AIs interchangeable. Guidelines don’t favor one. But this large, rigorous emulated target trial suggests anastrozole or letrozole may be preferable upfront over exemestane for adjuvant therapy. However — exemestane showed a slightly better lipid profile, a nuance important for patients with metabolic comorbidities. ⚠️ Critical point: This is observational but methodologically robust. It fills the gap left by underpowered RCTs (FATA-GIM3, MA.27) and reflects *real-world* effectiveness, not just efficacy. Bottom line: In the absence of predictive biomarkers for AI selection, this evidence nudges us toward **letrozole or anastrozole as first choice**, especially in higher-risk cases. We need more translational research to understand why and for whom exemestane might still be suitable. REF: JAMA Network Open.2025;8(12):e2550842. DOI: 10.1001/jamanetworkopen.2025.50842 @OncoAlert @hoperugo

𝐇𝐢𝐠𝐡-𝐯𝐨𝐥𝐮𝐦𝐞 𝐝𝐢𝐬𝐞𝐚𝐬𝐞 𝐧𝐞𝐞𝐝𝐬 𝐞𝐚𝐫𝐥𝐲 𝐢𝐧𝐭𝐞𝐧𝐬𝐢𝐟𝐢𝐜𝐚𝐭𝐢𝐨𝐧.
𝐋𝐨𝐰-𝐯𝐨𝐥𝐮𝐦𝐞 𝐝𝐢𝐬𝐞𝐚𝐬𝐞 𝐝𝐨𝐞𝐬𝐧’𝐭 𝐚𝐥𝐰𝐚𝐲𝐬. Here's a 𝐬𝐢𝐦𝐩𝐥𝐞, 𝐞𝐯𝐢𝐝𝐞𝐧𝐜𝐞-𝐛𝐚𝐬𝐞𝐝 𝐟𝐫𝐚𝐦𝐞𝐰𝐨𝐫𝐤 to choose 𝐝𝐨𝐮𝐛𝐥𝐞𝐭 𝐯𝐬 𝐭𝐫𝐢𝐩𝐥𝐞𝐭 in mHSPC—
guided by 𝐏𝐄𝐀𝐂𝐄-𝟏 𝐚𝐧𝐝 𝐀𝐑𝐀𝐒𝐄𝐍𝐒. #OncologyEducation #mHSPC #PEACE1 #ARASENS
#ProstateCancer #MVOnco

𝐃𝐅𝐒, 𝐏𝐅𝐒, 𝐄𝐅𝐒 — 𝐬𝐚𝐦𝐞 𝐥𝐞𝐭𝐭𝐞𝐫𝐬. 𝐕𝐞𝐫𝐲 𝐝𝐢𝐟𝐟𝐞𝐫𝐞𝐧𝐭 𝐪𝐮𝐞𝐬𝐭𝐢𝐨𝐧𝐬. 🔹 𝐃𝐅𝐒: Did the disease come back?
🔹 𝐏𝐅𝐒: Did the disease grow?
🔹 𝐄𝐅𝐒: Did anything go wrong? Endpoints matter.
𝐂𝐨𝐧𝐭𝐞𝐱𝐭 𝐦𝐚𝐭𝐭𝐞𝐫𝐬 𝐦𝐨𝐫𝐞. 🧠 #Oncology #ClinicalTrials
#EvidenceBasedMedicine #MVOnco

2025 approvals: Summary of 7 new drugs/indications in GI malignancies by @FDAOncology 1. #Sotorasib 2. #Pembrolizumab 3. #Cabozantinib in NET 4. #Ipilimumab & #Nivolumab x2 5. #Retifanlimab in Anal Ca 6. #Durvalumab GEJ/Gastric Ca #gism #OncTwitter #MedTwitter

The Paclitaxel + Carboplatin "CarboTaxol" doublet is the bread and butter of oncology for a reason. 🍞🧈 But why does this specific combo work so well? It’s all about the "Freeze and Snap" synergy. ❄️💥 1️⃣ The Freezer (Paclitaxel): Paclitaxel stabilizes microtubules, preventing depolymerization. It freezes the cell’s skeleton in the M-phase (Mitosis). The cell tries to divide but gets stuck. 🛑  2️⃣ The Snap (Carboplatin): While the cell is arrested and stressed, Carboplatin slides in. It acts as an alkylating agent, forming reactive platinum complexes that bind to DNA (cross-linking). 🧬🔗  🤝 The Synergy (Why 1+1 = 3): The magic lies in the timing. Paclitaxel arrests cells in the G2/M phase. Cells in this phase are less efficient at repairing the DNA damage caused by Carboplatin. The "Freeze" prevents the "Repair," leading to accumulation of DNA damage ➡️ Apoptosis (Cell Death). ☠️  💡 Clinical Pearl (The Sequence Matters): This is why we often administer Taxane before Platinum. Giving Paclitaxel first avoids the antagonistic effect where Carboplatin might inhibit the uptake or cytotoxicity of the taxane. It also reduces thrombocytopenia! 📉🩸 #Oncology #MedTwitter #OncTwitter @OncoAlert @myesmo @esmo_open @asco

What’s new in the space of antibody-drug conjugates (ADCs) for metastatic castration-resistant prostate cancer (mCRPC)? Congratulations to Bene @bcarneiro7,  Claire, and colleagues @weldeiry for publishing this outstanding state-of-the-art review in NPJ Precision Oncology @Nature_NPJ  PMID:41238753  DOI: 10.1038/s41698-025-01131-0 ADCs represent a rapidly evolving class of biotherapeutics, combining the tumor-targeting specificity of monoclonal antibodies with the cytotoxic potency of small-molecule payloads. This comprehensive review outlines advances in cytotoxic payload and linker chemistry, and synthesizes emerging evidence on membrane antigens overexpressed in prostate cancer - including PSMA, B7-H3, STEAP1, TROP2, CD46, TF, DLL3, SLC44A4, HER2/HER3, Nectin-4, 5T4, KAAG1, ASCT2, LYPD3, Tag-72, TM4SF1, CDH3, ROR1, and PSCA. Although no ADC has yet been approved for prostate cancer due to challenges related to safety, specificity, and therapeutic window, progress in antigen selection, linker design, and next-generation payloads is accelerating development. These innovations hold significant promise to reshape the treatment paradigm for mCRPC and improve patient outcomes.

🧬🍽️ Hereditary Diffuse Gastric Cancer (HDGC) 🆚 Lynch SD 🔹 HDGC: CDH1/CTNNA1 → early diffuse GC 🔹 Lynch: decades of progress, clear surveillance. 📚 Lessons from LS: new genes, better variant interpretation, refined surveillance ➡️ Time to accelerate HDGC care & research 🔗 doi.org/10.1038/s41431… @OncoAlert

2025 approvals: Summary of 5 new drugs/indications in #BreastCancer & #GynOnc by Santa aka @US_FDA 1. #DatoDXd 2. #TDXd x2 3. #Imlunestrant 4. #Avutometinib/#Defactinib: Ovarian Ca #bcsm #OncTwitter #MedTwitter #HappyHolidays #MerryChristmas

T-DXd: Mechanism of Action — Visualized A few years ago, we were actively looking for professional illustrators to create figures like these. Now, a single-line prompt is often enough to generate high-fidelity, scientifically accurate visuals💥