Seiji Ito1, Mitsuro Kanda2, Yoshinari Mochizuki3, Hitoshi Teramoto4, Kiyoshi Ishigure5, Toshifumi Murai6, Takahiro Asada7, Akiharu Ishiyama8, Hidenobu Matsushita9, Chie Tanaka2, Daisuke Kobayashi3, Michitaka Fujiwara2, Kenta Murotani10, Yasuhiro Kodera2. 1. Department of Gastroenterological Surgery, Aichi Cancer Center Hospital, 1-1 Kanokoden, Chikusa-ku, Nagoya, 464-8681, Japan. seito@aichi-cc.jp. 2. Department of Gastroenterological Surgery (Surgery II), Nagoya University Graduate School of Medicine, Nagoya, Japan. 3. Department of Surgery, Komaki Municipal Hospital, Komaki, Japan. 4. Department of Surgery, Yokkaichi Municipal Hospital, Yokkaichi, Japan. 5. Department of Surgery, Konan Kosei Hospital, Konan, Japan. 6. Department of Surgery, Ichinomiya Municipal Hospital, Ichinomiya, Japan. 7. Department of Surgery, Gifu Prefectural Tajimi Hospital, Tajimi, Japan. 8. Department of Surgery, Okazaki City Hospital, Okazaki, Japan. 9. Department of Surgery, Tosei General Hospital, Seto, Japan. 10. Biostatistics Center, Graduate School of Medicine, Kurume University, Kurume, Japan.
Abstract
BACKGROUND: Splenectomy for proximal gastric cancer was found to have no survival benefit in a randomized trial clarifying the role of splenectomy (JCOG0110 study). However, since tumor with invasion to the greater curvature and Type 4 tumor were excluded in JCOG0110, the benefit of splenectomy for these tumors is not known. METHODS: A multicenter dataset of patients with gastric cancer who underwent gastrectomy between 2010 and 2014 was created. From the dataset, 114 eligible patients with proximal advanced gastric cancer with invasion to the greater curvature or Type 4 tumor were enrolled. There were 60 patients in the gastrectomy with splenectomy (Spx) group and 54 patients in the spleen-preserving (Prs) group. To balance the essential variables, propensity score analysis was performed, estimating the propensity score with a logistic regression model. Adjusted overall survival (OS) and adjusted disease-free survival (DFS) were estimated using the inverse probability of treatment weighting (IPTW) method. RESULTS: There were significant differences in age, performance status, comorbidity, macroscopic type, and clinical T stage between the Spx and Prs groups. The model for estimating the propensity score was well adapted (c-statistic: 0.830, 95%CI: 0.754-0.906). Adjusted OS was identical between the two groups (HR = 1.089, 95%CI: 0.759-1.563; p = 0.644). The DFS curve of Prs group was consistently tended to be lower than Spx, but the difference was not significant (HR = 0.813, 95%CI: 0.572-1.156; p = 0.249). CONCLUSIONS: The efficacy of splenectomy was minimal for proximal advanced gastric cancer even with invasion to the greater curvature or Type 4 tumor.
BACKGROUND: Splenectomy for proximal gastric cancer was found to have no survival benefit in a randomized trial clarifying the role of splenectomy (JCOG0110 study). However, since tumor with invasion to the greater curvature and Type 4 tumor were excluded in JCOG0110, the benefit of splenectomy for these tumors is not known. METHODS: A multicenter dataset of patients with gastric cancer who underwent gastrectomy between 2010 and 2014 was created. From the dataset, 114 eligible patients with proximal advanced gastric cancer with invasion to the greater curvature or Type 4 tumor were enrolled. There were 60 patients in the gastrectomy with splenectomy (Spx) group and 54 patients in the spleen-preserving (Prs) group. To balance the essential variables, propensity score analysis was performed, estimating the propensity score with a logistic regression model. Adjusted overall survival (OS) and adjusted disease-free survival (DFS) were estimated using the inverse probability of treatment weighting (IPTW) method. RESULTS: There were significant differences in age, performance status, comorbidity, macroscopic type, and clinical T stage between the Spx and Prs groups. The model for estimating the propensity score was well adapted (c-statistic: 0.830, 95%CI: 0.754-0.906). Adjusted OS was identical between the two groups (HR = 1.089, 95%CI: 0.759-1.563; p = 0.644). The DFS curve of Prs group was consistently tended to be lower than Spx, but the difference was not significant (HR = 0.813, 95%CI: 0.572-1.156; p = 0.249). CONCLUSIONS: The efficacy of splenectomy was minimal for proximal advanced gastric cancer even with invasion to the greater curvature or Type 4 tumor.