Appropriateness of splenectomy for advanced cancer located in the upper third of the stomach

Abstract

In cases of total gastrectomy for cancer located in the upper third of the stomach, the appropriateness of performing a splenectomy as a preventive dissection for spleen hilum lymph node (station number 10) has been broadly discussed in terms of both oncological principle and operational safety; however, no conclusions have yet been reached. Regarding our report [1], Hanisch and Ziogas [2] questioned whether or not it was appropriate, based on oncological principles, to select a surgical procedure of spleen preservation for advanced cancer located in the upper third of the stomach, in particular for cases of pathologically advanced serosa-positive (pT3) and nodepositive disease. Certainly, in terms of oncological concerns, it is correct to point out that not performing a spleen hilum lymph node dissection for pT3 cases involves the risk of increasing the possibility of postoperative recurrence. This is because a surgical spleen hilum lymph node dissection can be expected to be effective because the spleen is an organ adjacent to the stomach, connected to the stomach via short gastric arteries, and also having a close relationship with the stomach through lymphatic routes. In fact, in Japan, for cases of advanced stomach cancer with wall invasion of pT2 or higher (pT2, T3, T4), gastrectomy together with a D2 lymph node dissection has been recommended as a standard therapy [3, 4]. The purpose of our present study is to compare the surgical results of laparoscopy-assisted total gastrectomy (LATG), which preserves the spleen, and open total gastrectomy (OTG). Candidates for LATG comprised cases of clinical T1 (cT1) early-stage stomach cancer, while candidates for OTG comprised cases of advanced cancers with lower potential for spleen hilum lymph node metastasis. Specifically, we conducted a retrospective analysis of cases with lesions sized 5 cm or less in which there was no infiltration of the serosa and the spleen was preserved for those in which the lesion did not come into contact with the greater curvature. In such cases, we believed that the risk of postoperative recurrence through spleen hilum lymph node metastasis was low. On the other hand, in cases in which the lesion-occupied region is the greater curvature or in which the diameter of the tumor is large, spleen hilum lymph node metastasis is highly likely to occur and total gastrectomy with splenectomy is therefore more likely to be necessary. For the OTG group in our present study, cases of up to cT2 in the preoperative diagnosis were selected as candidates; however, pathologically, pT3 was present in 13/44 cases (29.5%), thus indicating the difficulty in obtaining preoperative diagnosis of wall invasion. We hope there will be more progress in diagnostic techniques of wall invasion in the future. In retrospective studies of cases of splenectomy for cancer located in the upper third of the stomach in Europe and the USA [5, 6], in many cases, the 5-year survival rate of splenectomy cases is lower by 10% or more compared with cases of spleen preservation. However, it is believed that this reflects the fact that the splenectomy group contains more cases with high levels of advancement, or that these results are due to the poor short-term surgical results of the splenectomy group, and therefore, these results do not accurately reflect the oncological appropriateness of a splenectomy (i.e., the effects of lymph node dissection). On the other hand, in studies conducted in Japan, there are few reports in which the 5-year survival rate is improved by S. Sakuramoto (&) K. Yamashita M. Watanabe Department of Surgery, Kitasato University School of Medicine, 2-1-1 Asamizodai, Sagamihara, Kanagawa 228-8520, Japan e-mail: sakura@med.kitasato-u.ac.jp