Patterns of recurrence after curative resection and adjuvant chemotherapy in gastric and gastroesophageal junction cancer.

Distinct recurrence patterns of gastric cancer (GC) and Siewert II/III gastroesophageal junction cancer (GEJC) following curative resection and adjuvant chemotherapy remain unclear. We aimed to investigate the initial recurrence patterns of GC/GEJC following curative resection and adjuvant chemotherapy. We retrospectively analyzed recurrence sites and timing in 1255 patients with GC/GEJC (338 with GEJC; 917 with GC) treated with curative resection and adjuvant chemotherapy (2011-2018). Univariate and multivariate analyses were used to identify predictors of recurrence patterns. Of the 430 patients who experienced recurrence, complete data were available for 352 (124 with GEJC; 228 with GC). In GEJC, distant recurrence was predominant (47.6%), followed by multifocal (22.6%), peritoneal (15.3%), and locoregional (14.5%) recurrence. Peritoneal metastases occurred primarily within four postoperative years, with two late exceptions. In GC, multifocal recurrence was the most frequent (36.8%), followed by distant (29.8%), peritoneal (26.8%), and locoregional (6.6%) recurrence. A notable proportion of patients with GC developed peritoneal and distant metastases annually after surgery, even beyond 5 years postoperatively. Most recurrences occurred within 3 years (81.5% GEJC; 77.2% GC). Multivariate analysis identified GEJC as an independent risk factor for locoregional (hazard ratio [HR], 1.953; p = .008) and distant recurrences (HR, 1.618; p = .004). Recurrence patterns after curative resection and adjuvant chemotherapy vary significantly between patients with GEJC and those with GC, and surveillance strategies should be tailored according to their respective characteristics. Intensive follow-up within the first 3 years is recommended for patients with GC/GEJC.