Laparoscopic D2 gastrectomy with complete mesogastrium excision (D2+CME) to reduce cancer leak from mesogastrium in patients with advanced gastric cancer.

Abstract

18 Background: The mechanism underlying tumor recurrence following curative surgery remains unclear. It is believed that intraperitoneal free cancer cells leaked into peritoneal cavity during curative surgery play an important role. In gastric cancer, new strategies should be established towards preventing leakage of cancer cells from the primary tumor involved tissues. Our previous research demonstrated the existence of disseminated cancer cells in the mesogastrium, and we proposed laparoscopic D2 lymphadenectomy plus complete mesogastrium excision (D2+CME) as an optimized surgical procedure for advanced gastric cancer (AGC). By dissecting along the surgical planes and embryonic boundary of mesogastrium, D2+CME is repeatable with less blood lost and improved short-term surgical outcomes. In this study, we further evaluated the oncological effect of D2+CME based on the detection of “cancer leak”. Methods: The peritoneal washings were collected prior to and after tumor resection from 45 patients who underwent D2+CME (D2+CME group) and 46 patients who underwent conventional D2 lymphadenectomy (D2 group). RT-PCR was used to determine the presence of cancer cells. Positive samples are defined as those with CEA mRNA level over threshold (cutoff value). Results: Of 91 peritoneal washing samples obtained before gastrectomy, 84 (41 in D2+CME; 43 in D2 alone) showed no presence of cancer cell. After gastrectomy, CEA positive was detected in 17 of 43 (39.5%) samples with D2 group, however, only 5 of 41 (12.2%) samples in D2+CME group detected positive CEA. The average level of CEA expression in D2+CME group was also significant lower than that in D2 group after gastrectomy (p < 0.05). Presence of “cancer leak” was closely associated with pT stage and surgical procedures. The DFS of patients with CEA positive after gastrectomy was significantly poorer than that of patients with CEA negative (p < 0.05). Conclusions: LaparoscopicD2+CME could reduce the leakage of free cancer cells from the envelop of mesogastrium into the peritoneal cavity during radical gastrectomy, and thus, it might potentially increase the prognosis of AGC patients. Clinical trial information: NCT01978444.