📬 GI Cancer Intelligence Digest — Week 2026-W38

MATTERHORN final overall survival results (3-year OS 69% vs 62%, HR 0.78) establish perioperative durvalumab plus FLOT as a new standard in resectable gastric/GEJ adenocarcinoma, while the adagrasib-cetuximab withdrawal in KRAS G12C colorectal cancer and the daraxonrasib approval dominate the week's other GI conversations.

⚡ TL;DR

📄 Publications

Perioperative durvalumab plus fluorouracil, leucovorin, oxaliplatin, and docetaxel for resectable gastric and gastro-oesophageal junction adenocarcinoma (MATTERHORN): final results of overall survival and event-free survival by pathological response in a global, randomised, double-blind, placebo-controlled, multicentre, phase 3 trial. — 948 of 1258 enrolled participants were randomly assigned, 474 to durvalumab and 474 to placebo

🐦 Twitter / 🦋 Bluesky

MATTERHORN final overall survival: perioperative durvalumab plus FLOT becomes a new standard in resectable gastric/GEJ adenocarcinoma, with questions about diffuse-type and PD-L1-negative disease — MATTERHORN final results showed a 7% absolute improvement in 3-year OS with perioperative durvalumab plus FLOT (69% vs 62%; HR 0.78)

Full details below ↓

📄 What's Being Published

Manuscripts:

Perioperative durvalumab plus fluorouracil, leucovorin, oxaliplatin, and docetaxel for resectable gastric and gastro-oesophageal junction adenocarcinoma (MATTERHORN): final results of overall survival and event-free survival by pathological response in a global, randomised, double-blind, placebo-controlled, multicentre, phase 3 trial. — Janjigian Yelena Y et al., Lancet

In this phase 3 trial conducted across 147 medical centres in 20 countries, 948 of 1258 enrolled participants were randomly assigned — 474 to durvalumab and 474 to placebo — among adults with stage II–IVa resectable gastric or gastro-oesophageal junction adenocarcinoma. Overall survival significantly improved in the durvalumab versus placebo group (hazard ratio 0.78, 95% CI 0.63–0.96; p=0.021). Adverse events with the outcome of death possibly related to any trial treatment occurred in 6 (1%) of 475 participants in the durvalumab group and 2 (<1%) of 469 participants in the placebo group.

Clinical bottom line: Perioperative durvalumab plus FLOT should now be offered as standard treatment for resectable gastric and gastro-oesophageal junction adenocarcinoma, with the caveat that benefit in diffuse-type and PD-L1-negative disease remains contested.

Read full article →

🗂 Every paper considered this week, including the ones that didn’t make it →

🗣️ What People Were Discussing This Week

How these are chosen: filtered for clinical relevance, grouped by the new development discussed, then ordered by engagement (bookmarks and reposts).

MATTERHORN final overall survival: perioperative durvalumab plus FLOT becomes a new standard in resectable gastric/GEJ adenocarcinoma, with questions about diffuse-type and PD-L1-negative disease

MATTERHORN final results demonstrated a 7% absolute improvement in 3-year OS with perioperative durvalumab plus FLOT (69% vs 62%; HR 0.78), with the OS benefit reaching statistical significance (hazard ratio 0.78, 95% CI 0.63–0.96; p=0.021) across 948 patients, among whom pCR was 19% vs 7% and 2-year EFS was 67.4% vs 58.5% (HR 0.71). Notably, 67% of patients had less than a major pathological response — itself a prognostic finding — which some radiation oncologists argue supports testing adaptive radiotherapy to improve local response. The central debate is whether the 7% absolute 3-year OS gain justifies perioperative durvalumab for all comers, or whether diffuse-type and PD-L1-negative patients warrant a different treatment approach.

Discussed by: @Latinamd, @ronanhsieh, @NiuSanford

→ View representative tweet

Sources cited: The Lancet · Elsevier

🔥 Top Ranked Tweets

OncoAlert @OncoAlert

RT @OncoAlert: This week's OncoAlert 🚨 Newsletter is packed with practice-changing data: REGISTER TO GET IT 👉 https://t.co/NhtuRoIyO3

🚨 THIS WEEK IN ONCOLOGY 🚨

Zanidatamab-hrii just posted an improved OS hazard ratio in HER2+ gastroesophageal adenocarcinoma — and that's just the headline. This week's OncoAlert Newsletter also covers:

🎗️ Cemiplimab + fianlimab (dual PD-1/LAG-3 blockade) nearly doubling pCR rates in high-risk breast cancer (I-SPY2)
🫁 5-year AEGEAN data on perioperative durvalumab in resectable NSCLC
🧬 DEEPER trial's final word on FOLFOXIRI + cetuximab vs bevacizumab in left-sided mCRC
☢️ Radium-223 + enzalutamide accelerating biochemical responses in bone-metastatic mCRPC (PEACE-3)
🔬 TALENTOP: does liver resection after atezolizumab/bevacizumab extend disease control in advanced HCC?
Curated weekly, for colleagues, by colleagues — the biggest trial readouts and practice-changing data across GI, lung, breast, and GU oncology, distilled into a 2-minute read.

@matteolambe
@aftimosp
@E_de_Azambuja
@DrSGraff
@ErikaHamilton9
@double_whammied
@maryam_lustberg
@raalbany
@hoperugo
@stolaney1
@LoiSher
@JaniceTNBCmets
@montypal
@DrDanielHeng
@apolo_andrea
@DrChoueiri
@PGrivasMDPhD
@TiansterZhang
@neerajaiims
@amerseburger
@sonpavde
@drenriquegrande
@tompowles1
@cdanicas
@nataliagandur
@realbowtiedoc
@Onco_Cifu88
@scocmem
@FernandoOnco
@ElisaAgostinett
@to_be_elizabeth
@Erman_Akkus
@MarioBalsaMD
@DrMirallas
@GIMedOnc
@UOzkerim
@DrRishabhOnco
@PaulJiL
@DaisukeKotani
@DraMartinezLago
@p_ciracimd
@BenWestphalen
@CentralParkWMD
@graokane
@amandaNizamMD
@DrVilmaPBarcia