Expression of p53 protein in pancreatic adenocarcinoma. Relationship to cigaret smoking

Adenocarcinoma of the pancreas

Infiltrating ductal adenocarcinoma of the pancreas is a real enigma. On one hand, it is one of the most deadly of all of the solid malignancies. On the other hand, the neoplastic glands can be remarkably well-differentiated, and it can be difficult to distinguish between a reactive non-neoplastic gland and a gland of invasive adenocarcinoma. In this review, we will present diagnostic criteria that one can "hang your hat on" when establishing the diagnosis of infiltrating ductal adenocarcinoma of the pancreas. We will also review clinically important features of the disease, and, with the impending incorporation of molecular genetics into everyday practice, we will emphasize clinical applications of cancer genetics.

Meta-analysis of immunohistochemical prognostic markers in resected pancreatic cancer

BACKGROUND

The potential prognostic value of several commonly investigated immunohistochemical markers in resected pancreatic cancer is variably reported. The objective of this study was to conduct a systematic review of literature evaluating p53, p16, smad4, bcl-2, bax, vascular endothelial growth factor (VEGF) and epidermal growth factor receptor (EGFR) expression as prognostic factors in resected pancreatic adenocarcinoma and to conduct a subsequent meta-analysis to quantify the overall prognostic effect.

METHODS

Relevant literature was identified using Medline, EMBASE and ISI Web of Science. The primary end point was overall survival assessed on univariate analysis. Only studies analysing resected pancreatic adenocarcinoma were eligible for inclusion and the summary log(e) hazard ratio (logHR) and variance were pooled using an inverse variance approach. Evidence of heterogeneity was evaluated using the χ(2) test for heterogeneity and its impact on the meta-analysis was assessed by the I(2) statisic. Hazard ratios greater than one reflect adverse survival associated with positive immunostaining.

RESULTS

Vascular endothelial growth factor emerged as the most potentially informative prognostic marker (11 eligible studies, n=767, HR=1.51 (95% confidence interval, CI=1.18-1.92)) with no evidence of any significant publication bias (Egger's test, P=0.269). Bcl-2 (5 eligible studies, n=314, HR=0.51 (95% CI=0.38-0.68)), bax (5 studies, n=274, HR=0.63 (95% CI=0.48-0.83)) and p16 (3 studies, n=229, HR=0.63 (95% CI=0.43-0.92)) also returned significant overall survival differences, but in smaller patient series due to a lack of evaluable literature. Neither p53 (17 studies, n=925, HR=1.22 (95% CI=0.96-1.56)), smad4 (5 studies, n=540, HR=0.88 (95% CI=0.61-1.27)) nor EGFR (4 studies, n=250, HR=1.35 (95% CI=0.80-2.27)) was found to represent significant prognostic factors when analysing the pooled patient data. There was evidence of significant heterogeneity in four of the seven study groups.

CONCLUSION

These results support the case for immunohistochemical expression of VEGF representing a significant and reproducible marker of adverse prognosis in resected pancreatic cancer.

Molecular prognostic markers in pancreatic cancer

BACKGROUND

Pancreatic cancer is one of the most aggressive human tumors and is virtually incurable. Its incidence in the United States has tripled in the past 50 years. The tumor is a frequent cause of cancer death in both men and women. The current treatment options are inadequate and probably reflect the fact that the etiologic factors and the pathogenesis of pancreatic cancer are unknown.

METHODS

The author reviewed recent studies describing some of the molecular alterations that may play a role in pancreatic carcinogenesis.

RESULTS

Most pancreatic tumors arise in the ductal epithelium. Cytogenetic abnormalities and alterations in proliferation, oncogenes and tumor suppressor genes, cell receptors, and growth factors are described.

CONCLUSIONS

Preliminary studies have implicated, among others, the insulin-like growth factor-1 receptor, Src, and Stat3 proteins in human pancreatic carcinogenesis. These molecules may represent important predictors of tumor behavior and targets of novel therapeutic modalities in human pancreatic cancer.