In pancreatic adenocarcinoma, the presence of CD4+ TILs together with CD8+ TILs serves as a good indicator of the patient's outcome after surgical treatment.

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 þ or CD4 þ lymphocyte infiltration. Although the level of infiltration by CD8 þ T cells alone had no prognostic significance, the survival rate for patients with both 'high' CD8 þ and 'high' CD4 þ T-cell infiltration was significantly higher than that for the other groups (log-rank test, P ¼ 0.006). Multivariate analysis indicated that concomitant high CD8 þ and high CD4 þ T-cell infiltration was an independent favourable prognostic factor (P ¼ 0.0092). In conclusion, the presence of high levels of both CD8 þ T cells and CD4 þ 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.

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.

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 þ T cells, CD8 þ T cells, natural killer cells (NKCs), and dendritic cells (DCs). High levels of CD4 þ T cell, CD8 þ 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 þ and CD8 þ 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 þ and CD8 þ 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 cancerspecific activity of CD4 þ and CD8 þ T cells and DCs. In this study, we demonstrate that CD4 þ and CD8 þ tumour-infiltrating lymphocyte and DCs, but not NKCs, are important factors in the accurate prognosis of survival after surgical removal of gallbladder adenocarcinoma.

The infiltration of a cancer cell nest by CD8+ T cells is a reliable marker predicting increased survival of patients with EBDC.