Yield of Staging Laparoscopy and Lavage Cytology for Radiologically Occult Peritoneal Carcinomatosis of Gastric Cancer

Background: This study aimed to identify the yield of staging laparoscopy with peritoneal lavage cytology for gastric cancer patients and to track it over time. Methods: The medical records of patients with gastric or gastroesophageal adenocarcinoma who underwent pretreatment staging laparoscopy at the authors’ institution from 1995 to 2012 were reviewed. The yield of laparoscopy was defined as the proportion of patients who had positive findings on laparoscopy, including those with macroscopic carcinomatosis, positive cytology, or other clinically important findings. To compare the yield of laparoscopy over time, the patients were divided into three 6-year ranges based on the date of diagnosis. Associations between clinicopathologic factors and peritoneal disease were examined using uni- and multivariate analyses. Results: The study included 711 patients. Among these patients, 43.5 % had gastroesophageal junction tumors, 72.9 % had poorly differentiated adenocarcinoma, and 53 % had signet ring cell morphology. Endoscopic ultrasound had most commonly identified T3 (83.9 %) and N-positive (66.4 %) tumors. At laparoscopy, 148 (20.8 %) patients had been found to have macroscopic peritoneal carcinomatosis. Among 514 macroscopically negative patients who underwent peritoneal lavage cytologic analysis, 68 (13.2 %) had positive cytology results for malignancy. The total laparoscopy yield was 36 %, which did not change over time (p = 0.58). Multivariate analysis demonstrated that positive cytology or carcinomatosis was associated with poorly differentiated histology, linitis plastica, and equivocal computed tomography findings. Conclusions: Laparoscopy remains a useful staging procedure to evaluate for peritoneal spread when treatment or surgery is considered, even with the current availability of high-quality imaging.