Prediction of Peritoneal Recurrence in Patients with Gastric Cancer: a Multicenter Study.

PURPOSE: The peritoneum is the common recurrence site of gastric cancer (GC) presenting with worse survival. Although some predictive clinicopathological factors have been identified, there is no comprehensive assessment of peritoneal recurrence risk prediction for patients treated with adjuvant chemotherapy (CR) or chemoradiotherapy (CRT) after surgery. We aimed to predict peritoneal recurrence and develop a new scoring model in GC.

METHODS: This retrospective study included 274 GC patients who presented with recurrence after curative gastrectomy followed by adjuvant chemotherapy (CT) or chemoradiotherapy (CRT). Risk factors for peritoneal recurrence were analyzed using the following parameters: age, gender, tumor location and characteristics, and differences between treatment modalities. All parameters were assessed by binary logistic regression analysis to compare the patients with and without peritoneal recurrence. Then, a new risk scoring model was developed.

RESULTS: Peritoneal recurrence was observed in 115 (44.1%) patients. Peritoneal recurrence was higher in female gender (odds ratio (OR), 1.93; 1.07-3.49, P = 0.030, 1 point), T4a-b stage (OR, 2.47; 1.14-5.36, P = 0.022, 1 point), poor/undifferentiated (OR, 2.04; 1.31-4.06, P = 0.004, 1 point), and signet cell carcinoma (OR, 2.04; 1.04-4.02, P = 0.038, 1 point) after adjusted for resection and dissection types. The risk scoring model was developed using the related parameters: Peritoneal recurrence rates were 24.6%, 42.6%, and 71.4% for group 1 (0 point), group 2 (1-2 points), and group 3 (3-4 points), respectively.

CONCLUSION: Female gender, T4 tumor stage, undifferentiated histopathology, and signet cell type had a tendency to peritoneal recurrence after adjusted for treatment modalities. Patients with 3 or 4 risk factors had an 8.8-fold increased risk for the development of peritoneal recurrence.