Fig. 1.

Study flow chart. presents two distinct study flow cohorts of the same population, elucidating the prevalence of CNS metastases among patients diagnosed with GEC. The initial cohort encompasses all 3,283 patients, where 100 (3.04%) were found with BrM and 20 (0.61%) with LMC, regardless of if they were treated or followed up in our institution or not. It’s noteworthy that patients decided to received treatment in other centers, potentially impacting the accuracy of reported CNS metastasis frequencies. In the second cohort, comprising 2,230 patients actively monitored until death or achieving a disease-free survival of at least 5 years, the recalculated frequencies for BrM and LMC are 4.48% and 0.89%, respectively. This recalibration providing a more accurate representation of incidence within this specific patient group