ESMO Congress 2026

In oncology, "practice-changing" is a documented reality. In breast cancer surgery, for example, sentinel lymph node biopsy has supplanted axillary lymph node dissection (ALND) in clinically node-negative disease and select node-positive disease ^[3]; an analysis of 1,131,363 women with clinical Stage I-III breast cancer in the National Cancer Data Base (2004-2014) showed ALND rates declined from 32% in 2004 to 16% in 2014, with 255,306 receiving ALND and 876,057 undergoing non-ALND management, and resident procedural volume declining in parallel; the authors caution that ALNDs are increasingly performed in more challenging oncologic scenarios by potentially less-experienced surgeons ^[3]. This is the concrete referent of the "practice-changing" language recurring at #ESMO26: evidence strong enough to shift real-world practice rates ^[3].

The live posts disclosed no actual trial readout. The first post by @Alfdoc2 announces that ESMO Congress 2026 officially kicks off today, that he attends as one of the #ESMOAmbassadors, and that he will share highlights, key findings and his perspectives over the next few days, stating verbatim "Will we see practice-changing data? I suspect we will"; the second post addresses a separate item — the Plenary Session: he sits in the front row with colleagues @AndrearicFili, @MehrpouyaMobin, @RobertoFerrara_, @DrJNaidoo and @bensolomon1, describes the room as packed and expectations sky-high, and flags what could be "truly practice-changing data". As for which specific trial is being reported, drug names, tumor types, sample sizes or any efficacy figures, both posts leave them undisclosed and to be confirmed.

Relative to existing knowledge, these posts advance nothing at the evidence level, because they contain no data; their increment is temporal and logistical: ESMO 2026 opened that day, and the Plenary Session is explicitly framed as the focal venue where practice-changing data may emerge. Compared with the quantified practice shift in ^[3] (from 32% down to 16%), the posts offer no comparable numbers, so whether this year's data could drive a shift of similar magnitude cannot be judged before the results are formally presented; the author himself only expresses expectation with "I suspect" and plans to follow up throughout the congress.

The limitation lies exactly here: these are anticipatory posts from an ambassador account at the congress opening, with no trial identifiers, endpoints, sample sizes or result figures, and the background literature ^[3] covers only US breast cancer surgical practice from 2004-2014 rather than ESMO trials; any assessment of a specific readout must wait for formal disclosure, with details to be confirmed.