Patient Journey and Treatment Patterns of Gastric and Gastroesophageal Junction Cancer in Two Mexican Reference Centers

Background: Gastric and gastroesophageal junction cancers (GC/GEJC) represent leading causes of cancer-related mortality in Mexico. Outcomes remain poor, partly because of delayed and non-guideline-concordant care. Objectives: To describe the clinical profile, diagnostic and treatment intervals, and treatment patterns of newly diagnosed GC/GEJC in two Mexican reference centers according to stage at diagnosis. Methods: Retrospective, non-interventional study of patients treated at INCan and INCMNSZ, Mexico City, between 2005 and 2019. Results: Among the 1386 patients analyzed, the median interval from symptom onset to confirmed diagnosis was 123 days, and the median interval from diagnosis to treatment initiation was 50 days. Stage IV disease was recorded in 67.3% (n = 926/1376) of patients with available stage. Surgery was performed in 40.8% (n = 566/1386) of patients and gastrectomy in 18.3% (n = 254/1386); in stage IV disease, 85.0% (n = 233/274) of operated patients did not undergo gastrectomy. First-line systemic therapy for advanced disease was administered to 44.5% (n = 617/1386) of patients. Neoadjuvant chemotherapy was administered to 18.8% (n = 78/416) of candidates for perioperative chemotherapy (stage IB–IIIC). Adjuvant therapy was delivered to 24.0% (n = 332/1386) of the cohort, and adjuvant chemotherapy alone to 13.0% (n = 180/1386). HER2 status was undocumented in 67.0% (n = 928/1386) of patients; among patients with available results, 9.9% (n = 45/453) were HER2-positive. Conclusions: This study identifies substantial obstacles to timely diagnosis and optimal management of GC/GEJC in Mexico. Standardized protocols, early detection strategies, and routine biomarker testing are needed.