Diagnostic staging laparoscopy in gastric cancer: a prospective cohort at a cancer institute in Japan

There have been many studies that describe the value of diagnostic staging laparoscopy (DSL) in gastric cancer. However, different studies use different indications, making study results difficult to compare. This study aimed to clarify the diagnostic feasibility of DSL for gastric cancer in a prospective manner and investigated the impact of DSL on clinical decision-making in gastric cancer treatment. The study was a prospective cohort study based at a single institution between January 2010 and December 2013. We treated 2213 patients with potentially resectable gastric cancer during this period. DSL was primarily indicated for asymptomatic patients with: (1) large Borrmann type 3 tumours >= 8 cm, (2) Borrmann type 4 tumours (linitis plastica), (3) bulky lymph nodes or paraaortic lymph node swelling, or (4) clinical suspicion of peritoneal disease. The primary outcome is change in treatment strategy, and the secondary outcomes are diagnostic accuracy of the indications and false negative rate of DSL. DSL was performed on 156 (7%) of 2213 patients. Of these, peritoneal disease was found in 74 (47%) patients: (1) 56% for large type 3, (2) 54% for type 4, (3) 21% for bulky lymph nodes or paraaortic lymph node swelling, and (4) 20% for suspected peritoneal disease. The diagnostic accuracy of our indication for DSL was 92% for all patients and 74% for patients with cT3/T4 tumours. Among 82 patients without peritoneal disease, 66 patients (81%) underwent subsequent radical gastrectomy; peritoneal disease was discovered intraoperatively for 7 patients at laparotomy, indicating a false negative rate of 11%. We confirmed that DSL performed according to our indication, in the context of gastric cancer, possesses diagnostic feasibility. Approximately half of the patients who underwent DSL consequently avoided unnecessary laparotomy and were able to receive appropriate alternative treatment.