Prognostic factors in resectable pancreatic cancer: p53 and bcl-2.

The p53 tumor suppressor gene and the Bcl-2 proto-oncogene regulate cell cycle progression and apoptosis. We evaluated the expression of these molecular markers with standard pathologic prognostic variables in patients who received multimodality therapy for resectable adenocarcinoma of the pancreas to study the effect of p53 and Bcl-2 on survival duration. Immunohistochemical staining of archival material was performed to determine levels of expression of p53 and Bcl-2 proteins in 70 patients with adenocarcinoma of pancreatic origin. All patients underwent a potentially curative pancreaticoduodenectomy and standardized pathologic analysis of resected specimens. Potential pathologic and molecular prognostic variables were assessed for their effect on survival duration. Nuclear staining for p53 was observed in 33 (47%) of 70 specimens. Immunostaining for Bcl-2 was observed in 23 specimens (33%). A trend toward improved survival duration was seen in patients whose tumors stained positive for either p53 or Bcl-2. Negative staining for both markers predicted short survival (P = 0.01). By univariate and multivariate analyses, no single pathologic factor was associated with survival duration. Immunohistochemical staging using both p53 and Bcl-2 significantly predicted survival duration by univariate and multivariate analysis; patients whose tumors stained positively for p53 and/or overexpressed Bcl-2 had a significantly longer survival than those whose tumors stained negative for both proteins.

Cancer vaccines. Part 2.

Cancer vaccines are being widely studied for the purpose of immune modulation and subsequent antitumor effects. This article cites only a few examples of the many studies underway. Many vaccines have shown efficacy in eliciting systemic responses with minimal toxicities. The use of vaccines as a modality of cancer therapy in combination with chemotherapy, surgery, and radiation therapy is also being investigated. Although the routine use of approved vaccines is still a goal for the future, instituting this fourth modality of cancer therapy is not too distant. Phase III trials with both melanoma and colon cancer vaccines have been completed. Synthetic carbohydrate antigen vaccines have shown efficacy in several tumor types during Phase II trials and are also generating enthusiasm. The potential impact of vaccine therapy on the profession of pharmacy may involve patient counseling regarding management of side effects and possibly also dispensing of vaccine therapy products to patients directly for home administration. As ambulatory sites open in conjunction with pharmacy services and pharmacists obtain prescribing authority, pharmacists' active involvement in vaccine counseling and administration seems likely.

Cancer vaccines (1).

Several cancer vaccines are in various phases of clinical research. As vaccine therapy evolves, this method of treating and/or preventing cancer will become more common. Part 2 of this column will describe some of the current vaccine studies and where vaccine therapy may be headed in the future.