Predicting factors of unexpected peritoneal seeding in locally advanced gastric cancer: Indications for staging laparoscopy

Background and Objectives: The aim of this study is to investigate predictive factors for unexpected peritoneal seeding from clinically resectable advanced gastric cancers to suggest the indications for staging laparoscopy (SL). Methods A total of consecutive 589 gastric cancer patients who were clinically diagnosed with advanced gastric cancer with no metastatic disease underwent operations at Seoul St. Mary's Hospital. Results A total of 72 patients (including 35 patients with seeding to distant peritoneum) were surgically diagnosed with peritoneal seeding. Borrmann type 3 (OR: 4.475) or type 4 (OR: 8.243) cancer, tumor invasion of T3 (OR: 2.794) or T4 (OR: 6.841) and tumor size (4a ≤ tumor size < OR: 3.723 and 8 cm ≤ tumor size; OR: 6.971) were predictive factors for overall peritoneal seeding. Borrmann type 3 (OR: 3.524) or 4 (OR: 4.695) cancer, tumor invasion of T3 (OR: 4.378) or T4 (OR: 15.817), and tumors involving the anterior wall (OR: 2.762) also turned out to be predictive factors for distant peritoneal seeding. Conclusions If SL were performed by these predictive factors, this should have been performed in 42.4% of advanced gastric cancers and the detection rates for overall peritoneal seeding would have been 24.0%.