We focused on the impact of postoperative infection on long-term survival after potentially curative resection for gastric cancer. Postoperative surgical and medical complications have been implicated as a negative predictor of long-term outcome in various malignancies. However, there have been no published reports assessing the impact of complications arising from postoperative infection on survival in gastric cancer. We studied a population of 1,332 patients who underwent curative resection for gastric cancer. These patients were divided into two groups based on the occurrence (141 patients, 10.6%) or absence (1,191 patients, 89.4%) of postoperative complications due to infection. We investigated the demographic and clinicopathological features of each patient with and without postoperative complications from infection, and thereby the impact of postoperative infection on long-term survival. Patients with postoperative infection had significantly higher frequency of males, upper side tumor location, and total gastrectomy as a surgical procedure, more advanced stage of gastric cancer, and greater age compared with those without postoperative infection. Patients with complications due to postoperative infection had significantly more unfavorable outcome compared with those patients without postoperative infection. Multivariate analysis demonstrated that age, preoperative comorbidity, blood transfusion, tumor depth, nodal involvement, and postoperative infection correlated with overall survival. We conclude that postoperative complications from infection are a predictor of adverse clinical outcome in patients with gastric cancer. However, further immunological study and prospective trials are necessary to confirm the biological significance of these findings.

The OSNA method is feasible and acceptable for detecting LN metastases in patients with gastric cancer. This should be applied for the intraoperative diagnosis in the SN-navigation surgery in gastric cancer.

Surgical injury can be a life‐threatening complication, not only due to the injury itself, but also due to immune responses to the injury and subsequent development of infections, which readily result in sepsis. Sepsis remains the leading cause of death in most intensive care units. Unfavorable outcomes of several high‐profile trials in the treatment of sepsis have led researchers to state that sepsis studies need a new direction. The immune response that occurs during sepsis is characterized by a cytokine‐mediated hyper‐inflammatory phase, which most patients survive, and a subsequent immunosuppressive phase. Therefore, therapies that improve host immunity might increase the survival of patients with sepsis. Many mechanisms are responsible for sepsis‐induced immunosuppression, including apoptosis of immune cells, increased regulatory T cells and expression of programmed cell death 1 on CD4+ T cells, and cellular exhaustion. Immunomodulatory molecules that were recently identified include interleukin‐7, interleukin‐15, and anti‐programmed cell death 1. Recent studies suggest that immunoadjuvant therapy is the next major advance in sepsis treatment.

CD47 is an antiphagocytic molecule that acts via ligation to signal regulatory protein alpha on phagocytes; its enhanced expression and therapeutic targeting have recently been reported for several malignancies. However, CD47 expression in gastric cancer is not well documented. Immunohistochemical expression of CD47 in surgical specimens was investigated. Expression of CD47 and CD44, a known gastric cancer stem cell marker, were investigated in gastric cancer cell lines by flow cytometry. MKN45 and MKN74 gastric cancer cells were sorted by fluorescence-activated cell sorting according to CD44 and CD47 expression levels, and their in vitro proliferation, spheroid-forming capacity, and in vivo tumorigenicity were studied. In vitro phagocytosis of cancer cells by human macrophages in the presence of a CD47 blocking monoclonal antibody (B6H12) and the survival of immunodeficient mice intraperitoneally engrafted with MKN45 cells and B6H12 were compared to experiments using control antibodies. Immunohistochemistry of the clinical specimens indicated that CD47 was positive in 57 out of 115 cases, and its positivity was an independent adverse prognostic factor. Approximately 90% of the MKN45 and MKN74 cells expressed CD47 and CD44. CD47hi gastric cancer cells showed significantly higher proliferation and spheroid colony formation than CD47lo, and CD44hiCD47hi cells showed the highest proliferation in vitro and tumorigenicity in vivo. B6H12 significantly enhanced in vitro phagocytosis of cancer cells by human macrophages and prolonged the survival of intraperitoneal cancer dissemination in mice compared to control antibodies. In conclusion, CD47 is an adverse prognostic factor and promising therapeutic target in gastric cancer.

Among systemic immunoinflammatory measures, CAR was the most significant predictor of OS in patients with esophageal cancer. CRP and albumin levels were more important components of systemic immunoinflammatory measures.