Role of diagnostic laparoscopy in gastric cancer staging

Despite declining incidence, gastric cancer remains one of the most common cancers worldwide and one of the most common causes of cancer-related mortality. Accurate staging forms the basis for making appropriate decisions on treatment strategies for patients with gastric cancer; whether to select curative intent resection, palliative resection and/or referral for neo-adjuvant therapies. The importance of pre-operative staging is highlighted by the significant morbidity and mortality rates associated with an exploratory laparotomy for unresectable disease. Radiological investigations are performed preoperatively, however, there is a reported considerable rate of under-staging by non-invasive imaging modalities. The addition of diagnostic laparoscopy for certain patients improves clinical staging of patients with gastric cancer as it enables better detection of peritoneal seeding, tumor deposits to non-local lymph nodes and liver metastasis, which may not be detected by available imaging modalities. A complete staging laparoscopy should include the inspection of the stomach, diaphragm, liver and ovaries. Peritoneal washings for cytological analysis during staging laparoscopy have been advocated for the identification of free intraperitoneal cancer cells, despite the absence of any evidence of gross peritoneal disease, as the length of time added to the procedure is not significant. Positive cytology of peritoneal washings is a poor prognostic indicator and a strong predictor of recurrence even after an R0 resection and may impact treatment decisions with regards to perioperative therapy. This chapter will discuss the role of diagnostic laparoscopy in the staging of gastric cancer.