Optimizing Postoperative Management in Deficient Mismatch Repair/Microsatellite Instability-High Gastric or Gastroesophageal Junction Adenocarcinoma: A Multicenter Retrospective Study
The study aims to identify optimal postoperative management strategies for patients with dMMR/MSI-H gastric or gastroesophageal junction adenocarcinoma.
Included 156 patients with pathologically confirmed stage II-IVA dMMR/MSI-H adenocarcinoma who underwent D2 gastrectomy from 2015 to 2022.
Evaluated postoperative management strategies including observation, chemotherapy, immune checkpoint inhibitors (ICIs), or ICI-chemo.
Primary endpoint was 2-year event-free survival; secondary endpoints included event-free and overall survival.
The ICI-chemo group demonstrated the highest 2-year event-free survival at 87.5%.
Younger stage patients had significantly lower risk of progression (HR 0.29, 95% CI 0.16-0.53) and death (HR 0.30, 95% CI 0.14-0.64).
Event-free survival progressively improved from chemotherapy to observation and then to ICI-containing regimens.