A comparison of the clinicopathological features and genetic alterations in stage II/III gastric cancer with no recurrence, early recurrence and late recurrence after curative surgery.

Background: Few studies have explored the genetic changes and clinicopathological features of stage II/III gastric cancer (GC) patients with no tumor recurrence, early recurrence, or late recurrence after curative surgery.

Methods: In this study, 376 patients who underwent curative surgery for stage II/III GC were analyzed. The clinical and genetic features of patients with no recurrence, early recurrence (<2 years), and late recurrence (≥2 years) were compared.

Results: Among the 376 patients, 155 experienced tumor recurrence, including 116 with early recurrence and 39 with late recurrence. Patients with early recurrence had larger tumors, fewer superficial tumors, increased lymphovascular invasion, advanced T and N categories, higher TNM stages, and poorer 5-year survival (3.4% vs. 38.5% vs. 63.5%, p <0.001) than those with late recurrence or no recurrence. For intestinal-type GC, patients with early recurrence had more MSI-H tumors than those with late recurrence or no recurrence. For diffuse-type or node-positive GC, patients with early recurrence had more PIK3CA amplifications than did those with late recurrence or with no recurrence. Peritoneal dissemination and lung metastasis were associated with PIK3CA amplifications, whereas liver metastasis was associated with larger numbers of MSI-H tumors and PI3K / Akt pathway mutations. Multivariate analysis revealed that age, tumor recurrence, and pathological T and N categories were independent prognostic factors for both overall survival and disease-free survival.

Conclusion: Distinct clinical features and genetic alterations were observed in specific groups of stage II/III GC patients with differences in time to recurrence and recurrence patterns, and targeted therapy and immunotherapy may benefit these groups of patients.