Minimally invasive surgery for gastric cancer--toward a confluence of two major streams: a review.

The minimalization of therapeutic invasiveness in order to preserve quality of life (QOL) is a major topic in the management of early gastric cancer. After laparoscopic surgery for gastric cancer was introduced by Kitano et al. in 1991, an enthusiasm to develop laparoscopic procedures has grown steadily. In the initial phase, early gastric cancer limited to the mucosal layer with no risk of lymph node metastasis was treated by laparoscopic wedge resection or intragastric mucosal resection. Since technical and instrumental advances in endoscopic treatment were achieved by gastroenterologists, these cases can be managed by intraluminal endoscopic approaches. The attention of surgeons then shifted to more radical procedures such as laparoscopic gastrectomy with lymph node dissection, which is comparable to open surgery and can be indicated even in advanced cancer. Although this paradigm shift has already been realized in the field of colorectal surgery, we must pay attention to the particular biological nature of gastric cancer in terms of the potential of peritoneal dissemination. While early-phase recovery after surgery has been improved by laparoscopic surgery, preservation of late-phase QOL by function-preserving surgery is also essential in this regard; therefore, the sentinel node (SN) concept has been a much-discussed topic in gastric cancer surgery to approach this aspect. Recently, the validity of the SN concept has been demonstrated by a number of single institutional studies, and prospective multicenter trials are currently ongoing. Theoretically, various types of function-preserving surgery could be applied in cases of early gastric cancer with negative SNs as less invasive surgery to improve long-term QOL. Although we still have to solve several remaining issues in the treatment of gastric cancers, a confluence of these two major streams, laparoscopic surgery and sentinel node navigation surgery, would enable us to apply a novel individualized minimally invasive approach, both in terms of degree of incisional access and extent of function preservation.