Effects of Laparoscopic Radical Gastrectomy on Peritoneal Micrometastases of Gastric Cancer

Background: Some reports asserted that the stimulation of ultrasonic scalpel and the persistent state of carbon dioxide (CO2) pneumoperitoneum in laparoscopic surgery may affect the adhesion and invasion of gastric cancer (GC) cells. This study aimed to reveal the effects of laparoscopic radical gastrectomy on peritoneal micrometastases (PM) of GC. Materials and Methods: Fifty-three patients who underwent laparoscopic radical gastrectomy for GC were enrolled in the study. The expressions of carcinoembryonic antigen (CEA) mRNA and dopa decarboxylase (DDC) mRNA in peritoneal lavage fluid were detected by reverse transcription-polymerase chain reaction. The positive rates of CEA mRNA and DDC mRNA in preoperative peritoneal lavage fluid (pre-CEA, pre-DDC) were compared with those in postoperative lavage fluid (post-CEA, post-DDC). The correlation between the expressions of pre-CEA and pre-DDC and clinicopathologic factors and disease-free survival was analyzed. Results: There was no significant difference in the positive rates of pre-CEA and pre-DDC compared with those of post-CEA and post-DDC (all P>0.05). The positive rates of pre-CEA and pre-DDC increased with the increase of TNM stage, deepening of invasion, lymph node metastasis, and serosal invasion (all P<0.05), but had no correlation with tumor location, size, degree of differentiation, nerve invasion, and vascular invasion (all P>0.05). The disease-free survival in the combined positive patients was lower than that in the negative patients. Conclusions: Laparoscopic radical gastrectomy for GC is safe and feasible, without increasing the risk of PM. The PM of GC may be associated with late tumor stage, deep infiltration, lymph node metastasis, and serosal invasion.