Prognostic significance of natural killer cell activity in patients with gastric carcinoma: a multivariate analysis

OBJECTIVE: Natural cytotoxicity, mediated by natural killer (NK) cells, has been believed to play an important role in inhibiting experimental tumor metastasis, and diminished NK cell activities leads to a high incidence of tumor occurrence. Despite convincing evidence from experimental studies, the role of NK cells in the immunological surveillance against cancer in human is poorly defined. METHODS: The present study was based on a retrospective analysis of data on 156 patients with gastric cancer, who were surgically treated in the Department of Surgery II, Kyushu University Hospital from 1993 to 1996. All patients were examined for NK cell activity based on a peripheral blood sampling done preoperatively. RESULTS: Significant association between NK cell activity and clinicopathological parameters including tumor size, lymphatic involvement, vascular involvement, and lymph node metastases was evident. When comparing the two groups according to NK cell activity, tumors with low NK cell activity tend to have lymphatic involvement. The 5-yr survival rates were 94.6% and 72.3% for those with NK cell activity > 25% lysis and < or = 25% lysis, respectively, the value being statistically significant (p < 0.05). The independent risk factors for prognosis examined by logistic regression analysis were lymphatic involvement. NK cell activity, depth of tumor invasion, and lymph node dissection. CONCLUSIONS: These current data showed that NK cell activity may be related to tumor volume and dissemination. Measurement of preoperative NK cell activity may be pertinent for the prognosis of patients with gastric cancer and for follow-up clinical management.     

Two-field lymph-node dissection may be enough to treat patients with submucosal squamous cell carcinoma of the thoracic esophagus

Significance of extended radical surgical treatment including three-field lymph node dissection for squamous cell carcinoma (SCC) of the esophagus remains debatable. The aim of the current study was to reconsider the merits and demerits obtained by three-field lymph node dissection for esophageal carcinoma and also to attempt to elucidate an appropriate surgical strategy for submucosal SCC of the thoracic esophagus. Thirty-one patients with SCC of the thoracic esophagus who had been treated with esophagectomy and two-field (thoracic and abdominal) lymph node dissection without preoperative therapies were enrolled. Five-year survival rate was 75.0% and the incidence proportion of postoperative complication was 9.7%. These data regarding postoperative outcome of patients were by no means inferior to those in the previous reports referring the prognosis of patients with esophageal carcinoma who had been treated with three-field lymph node dissection. Authors would like to mention that two-field lymph node dissection associated with reduced incidence of postoperative complications might be enough to treat the submucosal SCC of the thoracic esophagus.     

Oxidative DNA damage in human esophageal cancer: clinicopathological analysis of 8‐hydroxydeoxyguanosine and its repair enzyme

Both internal and external oxidative stresses act on DNA and can induce carcinogenesis. 8‐hydroxydeoxyguanosine (8‐OHdG) is an indicator of oxidative stress and it leads to transversion mutations and carcinogenesis. 8‐OHdG is excision‐repaired by 8‐OHdG DNA glycosylase (OGG1). The purpose of this study is to clarify the effect of oxidative DNA damage and repair enzymes on esophageal carcinogenesis. The levels of 8‐OHdG and OGG1 were immunohistochemically evaluated in resected specimens, including squamous cell carcinoma (SCC) in 97 patients with esophageal cancer. Higher levels of 8‐OHdG in normal esophageal epithelium were associated with a higher smoking index (P = 0.0464). The 8‐OHdG level was higher in cancerous areas than in normal epithelia (P = 0.0061), whereas OGG1 expression was weaker in cancerous areas than in normal epithelia (P < 0.0001). An increase of OGG1 expression in normal epithelium was observed as 8‐OHdG levels increased (P = 0.0011). However, this correlation was not observed in cancerous areas. High OGG1 expression in the cytoplasm was related to deeper tumors (P = 0.0023), node metastasis (P = 0.0065) and stage (P = 0.0019). Oxidative DNA damage, which is attributable to smoking as well as disturbances in DNA repair systems, appears to be closely related to esophageal carcinogenesis and its progression.     

Laparoscopic trans-peritoneal hernioplasty (TAPP) is useful for obturator hernias: report of a Case

A 71-year-old female presented to our hospital due to pain from the right hip joint to the lower abdomen. The pain had suddenly appeared and spontaneously disappeared more than 10 times during the past 2 years. She had visited many hospitals, but remained undiagnosed. The patient underwent a computed tomography (CT) scan of the pelvis, and a soft tissue shadow was seen between the external obturator and pectineal muscles. She was diagnosed with a right obturator hernia and underwent elective repair by laparoscopic trans-peritoneal hernioplasty (TAPP). 1 year has passed since the surgery, without any recurrence of the abdominal pain. Obturator hernias are rare, and most cases are found as incarcerated hernias. It is rare to find an obturator hernia without intestinal obstruction, or with the recurrent pain as in our case. We herein report a case in which an obturator hernia was undiagnosed and intermittent pain was experienced for 2 years prior to TAPP, which appears to have successfully treated the hernia.