Iain Macpherson

Med Onc, Professor of Breast Oncology, University of Glasgow @UofGCancerSci

[COR2ED @COR2EDMedEd]

📣#BreastCancer highlights from #ASCO26!

Dr @PtarantinoMD shares his expert insights on key #trialdata from #ASCENT-03, ASCENT-04, #TROPION-Breast02, #SERENA-6, #VIKTORIA-1, & #OPTIMA

How will these data impact clinical practice? Watch his update to find out!

🤝 Programme endorsed by @WarOnCancer

📺See more updates from @ASCO in 𝘏𝘌𝘙2-mutant #NSCLC, #LungCancer, #GIcancer & #ProstateCancer
⬇️
https://t.co/jaRxEyx6Pg

This educational programme is supported by COR2ED

#MedEd #BCSM

[OncologyEducation @OncEd]

📈 Dr. Robert Stein discusses the OPTIMA trial, demonstrating that genomic testing can identify many patients with ER+/HER2− early breast cancer who may safely avoid chemotherapy.

https://t.co/QIGl0NPbxP

#ASCO2026

[Elisa Agostinetto @ElisaAgostinett]

Probably one of the most awaited abstracts of #ASCO26 - the results of the OPTIMA trial
Important results showing that pts with Prosigna ROR score < 60 in HR+HER2-neg EBC could safely avoid chemotherapy
Practice changing for premenopausal women >40yo treated with OFS
@OncoAlert

[Breast Cancer Trials @BCTrialsANZ]

Results from the OPTIMA trial show many patients aged 40+ with a low Prosigna score can safely avoid chemotherapy without increasing their risk of recurrence.

A significant step forward for personalised treatment.

🔗 https://t.co/Ooa6dxvykc

#ASCO2026

[Iain Macpherson @IR_Macpherson]

Fantastic evening discussing the landmark OPTIMA trial results! #optimabstudy

[TxMaverickMH @Hensley1552]

What a LEGENDARY Week!!! #OPTIMA

[TxMaverickMH @Hensley1552]

Prosigna #OPTIMA Trial, Game-Changing for Patients with Breast Cancer! 🔥🔥🔥

https://t.co/01NtYGqXZe

[PathforYoung @PathforYoung]

Stay tuned for #ASCO2026! OPTIMA trial results — including first insights in premenopausal population — will be presented. These data will contribute to the PATH-FOR-YOUNG / OPTIMA-YOUNG joint analysis on genomic assay–guided chemotherapy de-escalation. #PathForYoung #OptimaYoung

[Dr Rishabh Jain @DrRishabhOnco]

#ASCO26

Can genomic testing safely spare chemotherapy in high-risk ER+/HER2- early breast cancer?

The phase III OPTIMA trial says yes.

🧬 4,429 pts
🧪 Prosigna (PAM50)-guided strategy
🎯 Majority node-positive disease

Key finding:
Low-risk ROR (≤60) patients had excellent outcomes with endocrine therapy alone.

📉 5-year IBCFS:
• Standard chemo strategy: 94.9%
• Test-directed strategy: 93.7%
• HR 1.06 → met non-inferiority

👩 Premenopausal women on OFS also appeared to safely avoid chemotherapy.

This could expand genomic-guided de-escalation beyond the traditionally “low-clinical-risk” population.

Practice-changing signal for ER+ early breast cancer. 🌸

📖 Full abstract in comment ⬇️

#OncoTwitter #MedTwitter #BreastCancer #ASCO26 @OncoAlert @myesmo @esmo_open @ASCO @larvol

[PathforYoung @PathforYoung]

Great news! 🎉 OPTIMA-Young is moving fast towards opening its first centers in France 🇫🇷
The first centers are expected to start enrolling patients in the coming months — an important step forward for the project and for young breast cancer patients. #PathForYoung #OptimaYoung

[Mirrors of Medicine @mirrorsmed]

First results from the OPTIMA phase III randomized non-inferiority trial of test-directed chemotherapy in patients with high clinical risk ER-positive HER2-negative early breast cancer.
#ASCO26 Abstract Preview

https://t.co/WaYZYp5PXg

The OPTIMA trial evaluated Prosigna (PAM50)-guided chemotherapy🧪 decisions in over 4,400 patients with ER-positive, 🧬HER2-negative early #BreastCancer , most with node-positive disease. Patients with low recurrence-of-risk (ROR ≤60) tumors received endocrine therapy alone, while high-risk patients received chemotherapy plus endocrine therapy.

After 3.9 years median follow-up, test-directed treatment demonstrated non-inferior invasive breast cancer-free survival compared with standard chemotherapy, supporting safe omission of chemotherapy in low-ROR patients, including premenopausal and node-positive populations.

To be presented at #ASCO26

@IR_Macpherson
@IR_Macpherson @BelindaKiely @PeterHall001 @AdrienneICPV @StuartAMcI @CarmelConefrey

[OncoAlert @OncoAlert]

🚨 The OncoAlert #BreastCancer faculty’s TOP 10 abstracts for #ASCO26 — selected by our leads and finalized through a Delphi voting process with senior breast cancer experts.

1️⃣ 500 — OPTIMA
Test-directed chemotherapy in high-risk ER+/HER2- early BC
2️⃣ LBA1006 — PERSEVERA BC
Giredestrant + palbociclib vs letrozole + palbociclib in 1L ER+/HER2- LA/MBC
3️⃣ 507 — KEYNOTE-522 final analysis
Perioperative pembrolizumab in high-risk early TNBC
4️⃣ LBA1007 — SERENA-6
1L camizestrant for emergent ESR1 mutations — final PFS2
5️⃣ 502 — LIDERA BC
Giredestrant in ER+/HER2- early BC by menopausal status
6️⃣ LBA1000 — ASCENT-04
SG + pembrolizumab vs chemo + pembrolizumab in 1L PD-L1+ mTNBC
7️⃣ 501 — NATALEE biomarker analysis
Baseline gene expression and adjuvant ribociclib benefit
8️⃣ LBA503 — SENOMAC
Omission of axillary dissection: OS + arm morbidity
9️⃣ 1001 — ASCENT-03
SG vs chemotherapy in 1L mTNBC — PFS2
🔟 LBA1003
Izalontamab brengitecan vs physician’s choice chemo in metastatic TNBC

Leads🚨
@ElisaAgostinett
@to_be_elizabeth
@WeOncologists

Senior Faculty
@ErikaHamilton9
@E_de_Azambuja
@matteolambe
@DrSGraff
@hoperugo
@BianchiniGP
Dr. Bidard
@Icro_Meattini

Participating AF
@Lucarecco
@GaiaGriguolo

Ping Faculty
@aftimosp @double_whammied @stage4kelly @coffeemommy @itsnot_pink @maryam_lustberg @IBCResearch @kevinpunie @nicolobattisti @raalbany @teamoncology @stolaney1 @LoiSher @SirohiBhawna @chemobrainfog @jamecancerdoc @JavierCortesMD @JaniceTNBCmets @Prof_Nadia_H @paspears88 @MammaMiaMagazin @itrisabel

[MV Chandrakanth @ChandrakanthMv]

Clinical high risk does not always mean genomic high risk.

In the OPTIMA trial, many ER+/HER2− early breast cancer patients with node-positive disease — including premenopausal women — maintained excellent outcomes without routine chemotherapy when Prosigna/PAM50 ROR scores were low.

A major step toward biology-guided chemotherapy de-escalation.

Study: Stein et al, #ASCO2026

#BreastCancer #Oncology #MedEd #MVOnco

[Mali Barbi, MD MSc | Breast & Gyn Oncologist @DrBarbiOnc]

#ASCO26 | We've been sparing node-negative #breastcancer patients from chemo using #Oncotype. #OPTIMA just did it in the population we've been most afraid to touch. 4,400+ patients. ER+/HER2−. Node-positive, up to pN2.
#Prosigna_ROR: ≤60 → no chemo. 5-year IBCFS: 90.4% vs 91.5%. HR 0.99. Non-inferiority met!!!
No difference by nodal status. No difference by menopausal status, including premenopausal women on OFS. Here's what makes this more than a replication of #TAILORx or #RxPONDER: #Oncotype is driven by estrogen signaling. #Prosigna is driven by proliferation. Same tumor, different biology measured, different patients reclassified. >> This is the first RCT validating a proliferation-weighted test for chemo de-escalation in high-risk, node-positive disease.The question is no longer "does genomic testing work." It's which biology matters more for which patient.

More from Chicago next week. Follow along.
#ASCO26
@ASCO

[Iain Macpherson @IR_Macpherson]

Very exciting time for everyone involved. Looking forward to much discussion of the results and hopefully rapid implementation for real patient benefit

[Paolo Tarantino @PTarantinoMD]

The most important breast abstract from #ASCO26 is out. 4429 pts with ER+/HER2- BC randomized to SoC vs PAM50-directed adjuvant treatment. 19% had N2 dz (4-9 nodes), premenopausal pts received LHRHa. No benefit from chemo if ROR≤60. Looking forward to the full presentation.

[OncoDailyBreast @OncoDailyBreast]

Patient Journey in Chemotherapy De-Escalation Trials for Breast Cancer - Tanja Spanic

@TanjaSpanic @PathforYoung @MarziaZambon @Carmela_surgery @IR_Macpherson @ines_vazluis @AliceFranzoi

https://t.co/XVf9gLsPVb

#OncoDaily #Oncology #Cancer #Health #Medicine #BreastCancer #MedX #MedTwitter #PatientJourney

[Iain Macpherson @IR_Macpherson]

Honoured to be part of this fascinating and wide-ranging session. Communication, shared decision making and research characterised by prominent involvement of patient partners is key.

[Tanja Spanic @TanjaSpanic]

Survivorship starts at diagnosis.
#EBCC15, we highlighted how surgeons, radiation therapists, medical oncologists & patient advocates must work together to tailor early breast cancer treatment—around both clinical needs and patient voices.
@OncoAlert
@europadonna
@EORTC_BCG

[PathforYoung @PathforYoung]

On Jan 28th, the Path-for-Young General Assembly brought together investigators from all participating centers to share updates and plan the next steps toward the study launch. We also heard the latest progress from the OPTIMA trial, now nearing completion.

[Europa Donna @EuropaDonnaEUR]

💙 On #RareDiseaseDay, we highlight breast cancer in men: rare but real (1% of cases). Symptoms dismissed, stigma delays diagnosis. Awareness, info, listening—no one should face this alone. #MaleBreastCancer #BreastCancerAwareness @rarediseaseday @OncoAlert

[PathforYoung @PathforYoung]

Recruitment for the OPTIMA trial closed on 12 Dec 2025, reaching 98.5% of the 4,500-participant target. Around 1,650–1,660 premenopausal patients will contribute to Optima-young analysis. Thanks to all participants and teams for making this milestone possible. #PathforYoung