Efficacy of the electrothermal bipolar vessel sealer in laparoscopic spleen-preserving distal pancreatectomy with conservation of the splenic artery and vein.

INTRODUCTION: Laparoscopic spleen-preserving distal pancreatectomy (LSPDP) with conservation of the splenic artery and vein has recently been performed as a minimally invasive surgery to retain splenic function in the treatment of pancreatic diseases. As the branches of the splenic vessels are very delicate, division of these branches increases the risk of bleeding. MATERIALS AND METHODS: To overcome this problem, we have used the electrothermal bipolar vessel sealer (EBVS) to divide branches of the splenic vessels in LSPDP while conserving the splenic vessels themselves. RESULTS: The EBVS reliably provided excellent and safe hemostasis, minimizing the risk of serious blood loss. CONCLUSION: Use of the EBVS is safe and efficient in LSPDP with conservation of the splenic vessels.

Transcriptional targeting of adenovirus vectors with the squamous cell carcinoma-specific antigen-2 promoter for selective apoptosis induction in lung cancer.

Squamous cell carcinoma antigens SCCA1 and SCCA2 are highly homologous serine proteinase inhibitors which have been widely utilized as serological markers for squamous cell cancers, but it has recently been demonstrated that only SCCA2 is truly specific for certain forms of lung cancer. Using a construct containing the 5'-flanking region of the SCCA2 gene between -460 and +0 bp and the luciferase reporter gene, SCCA2 promoter activity was detected in SCCA2-producing SCC cell lines (LK-2, LC-1), but not in SCCA2-nonproducing lung adenocarcinoma cell lines (A549, ABC-1, and RERF-LC-MS) or normal cells (WI-38, SAEC, and NHEK-Adult). Infection with a recombinant adenovirus vector, Ad-SCCA2-DsRed, resulted in cell-specific expression of the SCCA2 promoter-driven DsRed marker gene only in LK-2 and LC-1 cells. The same strategy was used for SCCA2-driven expression of a proapoptotic gene, (KLAKLAK)2, which can cause mitochondrial disruption by triggering mitochondrial permeabilization and swelling, resulting in the release of cytochrome c and induction of apoptosis. Infection with Ad-SCCA2-KLAKLAK2 specifically reduced the growth of the two human lung SCC cell lines compared to the SCCA2 nonproducing cell lines both in vitro and in vivo, suggesting that the SCCA2 promoter had a tumor-specific effect. These results suggest that transduction of SCCA2 promoter-controlled suicide genes by adenoviral vectors can confer transcriptionally targeted cytotoxicity in SCCA2-producing lung SCC cells, and represents a novel strategy for gene transfer specifically targeted to SCC in the lung.

Concurrent infiltration by CD8+ T cells and CD4+ T cells is a favourable prognostic factor in non-small-cell lung carcinoma.

The purpose of this study was to clarify the relationship between the number of tumour-infiltrating T lymphocytes and the clinicopathological features and clinical outcome in patients with non-small-cell lung cancer (NSCLC). Tissue specimens from 109 patients who underwent surgical resection for NSCLC were immunohistochemically analysed for CD4 and CD8 expression. Patients were classified into two groups according to whether their tumours exhibited a 'high' or 'low' level of CD8(+) or CD4(+) lymphocyte infiltration. Although the level of infiltration by CD8(+) T cells alone had no prognostic significance, the survival rate for patients with both 'high' CD8(+) and 'high' CD4(+) T-cell infiltration was significantly higher than that for the other groups (log-rank test, P=0.006). Multivariate analysis indicated that concomitant high CD8(+) and high CD4(+) T-cell infiltration was an independent favourable prognostic factor (P=0.0092). In conclusion, the presence of high levels of both CD8(+) T cells and CD4(+) T cells is a significant indicator of a better prognosis for patients with NSCLC, and cooperation between these cell populations may allow a significantly more potent antitumour response than either population alone.

Clinical significance of immune cell infiltration within gallbladder cancer.

To investigate the pathophysiological significance of infiltrating antitumour immune cells, we evaluated the quantity of immune cell intratumoral infiltration in 110 surgically resected gallbladder specimens by immunohistochemistry. We examined 45 cases of gallbladder cancer and 65 cases of benign gallbladder diseases for CD4(+) T cells, CD8(+) T cells, natural killer cells (NKCs), and dendritic cells (DCs). High levels of CD4(+) T cell, CD8(+) T cell, NKC, and DC infiltration were recognised in 51.1% (23 out of 45), 37.8% (17 out of 45), 33.3% (15 out of 45), and 48.9% (22 out of 45) of cancer specimens, respectively. High numbers of infiltrating CD4(+) and CD8(+) T cells correlated with decreasing tumour invasion, and high numbers of infiltrating DCs correlated with decreasing lymph-node tumour metastasis. Furthermore, increased infiltration of CD4(+) and CD8(+) T cells and DCs exhibited a significant correlation with prolonged survival. NKC infiltration, however, did not correlate with any of the clinicopathological factors examined. Additionally, high levels of infiltration were not identified in specimens from benign diseases, consistent with the cancer-specific activity of CD4(+) and CD8(+) T cells and DCs. In this study, we demonstrate that CD4(+) and CD8(+) tumour-infiltrating lymphocyte and DCs, but not NKCs, are important factors in the accurate prognosis of survival after surgical removal of gallbladder adenocarcinoma.

Caveolin-I overexpression is a favourable prognostic factor for patients with extrahepatic bile duct carcinoma.

Extrahepatic bile duct carcinoma (EBDC) is a malignancy well known for its poor prognosis. Some clinicopathological prognostic markers have been proposed, but genetic factors have not been well investigated. We have examined expression patterns of caveolin-1, which has been shown to function as a tumour suppressor in vitro, in EBDC using immunohistochemistry. Normal tissues adjacent to the tumour cells did not show immunoreactivity for caveolin-1. A total of 22 of the 60-carcinoma tissue samples (36.7%) studied were positive for caveolin-1. Caveolin-1 immunostaining negatively correlated with the patient's age and pathological T factor (pT) in a statistically significant manner. Multivariate analysis using Cox's proportional hazards model identified caveolin-1 expression as an independent positive prognostic factor. Thus, our study suggests that caveolin-1 expression may be a useful prognostic marker for EBDC.

Impact of caveolin-1 expression on prognosis of pancreatic ductal adenocarcinoma.

Caveolin-1 is a major component of caveolae and plays a regulatory role in several signalling pathways. Caveolin-1 was recently identified as a metastasis-related gene in prostate cancer. The clinical effects of caveolin-1 expression in pancreatic carcinoma, however, remain unknown. In this study, we have investigated the relationship between caveolin-1 expression and the clinicopathologic variables and clinical outcome in 79 patients with pancreatic adenocarcinoma undergoing surgical resection. Caveolin-1 expression was determined by immunohistochemistry, using a polyclonal anti-caveolin-1 antibody. Patients were divided into two groups based on the extent of caveolin-1 expression: a negative expression group (immunoreactivity in less than 50% of cells) and a positive expression group. Positive caveolin-1 immunostaining was detected in 32 cases (40.5% of total), while non-neoplastic ductal epithelium showed little or no staining. Positive caveolin-1 expression was correlated with tumour diameter (P=0.0079), histopathologic grade (P=0.0272) and poor prognosis (P=0.0008). Upon multivariate analysis with Cox's proportional hazards model, positive caveolin-1 expression was shown to be an independent negative predictor for survival (P=0.0358). These results suggest that caveolin-1 overexpression is associated with tumour progression, thereby indicating a poor prognosis for certain patients undergoing surgical resection for pancreatic carcinoma.

RCAS1 as a tumour progression marker: an independent negative prognostic factor in gallbladder cancer.

Receptor-binding cancer antigen expressed on SiSo cells (RCAS1) induces apoptosis in immune cells bearing the RCAS1 receptor. We sought to determine RCAS1 involvement in the origin and progression of gallbladder cancer, and also implications of RCAS1 for patient survival. RCAS1 expression was examined immunohistochemically in 110 surgically resected gallbladder specimens. The gallbladders represented 20 cases of cholecystitis with no associated pancreaticobiliary maljunction; 23 cases of cholecystitis with pancreaticobiliary maljunction; 14 cases of adenomyomatosis; 7 adenomas; and 46 cancers. High expression of RCAS1 (immunoreactivity in over 25% of cells) was observed in 32 of the 46 cancers (70%), but not in other diseases, including pre-cancerous conditions. RCAS1 immunoreactivity was associated with depth of tumour invasion (P = 0.0180), lymph node metastasis (P = 0.0033), lymphatic involvement (P = 0.0104), venous involvement (P = 0.0224), perineural involvement (P = 0.0351) and stage by the tumour, nodes and metastases (TNM) classification (P = 0.0026). Thus, RCAS1 expression may be a relatively late event in gallbladder carcinogenesis, possibly promoting tumour progression. Cox regression multivariate analysis demonstrated RCAS1 positivity to be an independent negative predictor for survival (P = 0.0337; risk ratio, 12.690; 95% confidence interval, 1.216-132.423). High expression of RCAS1 significantly correlated with tumour progression and predicted poor outcome in gallbladder cancer.