Yannick Buccella, Gastrointestinal and Molecular Oncologist at City Hospital Zurich, shared on X:
“There’s a test that costs about as much as a taxi ride. In a trial reported today, it decided whether patients with esophageal and gastric cancer kept their esophagus or stomach.
Some cancers can’t fix copying errors in their own DNA, so mistakes pile up in the thousands. They are called dMMR.
This sounds catastrophic. It’s actually the opposite: a cell riddled with errors looks utterly foreign to the immune system. It only survives because the immune system is held back, and immunotherapy releases that brake.
So in this trial, patients weren’t operated on first. They got immunotherapy and were watched.
At one year, 62.5% had no detectable cancer. None of them has relapsed, they still have their stomachs. And that matters in terms of life quality and surgery risks.
This is an evolving field, we see similar and even more successful approaches in colorectal cancer, unfortunately it only applies to a small subset of patients, but it is definitely meaningful to the patients, who qualify.
And it all starts with a cheap stain on a biopsy. So if someone you love has stomach, esophageal or colorectal cancer, ask: ‘Has my/your tumor been tested for mismatch repair?’ For most, the answer changes nothing. For a few, it’s the difference between surgery and organ preservation.”
You can also read: ESMO 2026 Guideline: Key Updates in Gastric and Esophageal Cancer Management
