Objectives: The pathogenetic mechanisms that regulate the aggressive behavior of pancreatic cancer still remain to be clarified. Alterations in the apoptotic pathway and proliferative activity of tumor cells as well as mechanisms contributing to the intrinsic drug resistance of pancreatic tumors have been investigated. Survivin is a recently described antiapoptotic protein, which, when overexpressed, is associated with worse prognosis in a majority of tumors. P-glycoprotein, a product of multidrug resistance gene-1 (MDR-1) was reported to be expressed in drug-resistant tumors. The purpose of this study was to investigate whether apoptosis, its regulation by survivin, tumor cell proliferation, and P-glycoprotein expression have a significant role on the biologic behavior of pancreatic adenocarcinoma.
Methods: Tumors of 45 patients with pancreatic adenocarcinoma were studied for the detection of survivin, P-glycoprotein, and Ki-67 expression by immunohistochemical method and apoptotic index by TUNEL method. Immunohistochemical staining was scored and Ki-67 and apoptotic indices were expressed as percentage of stained cells.
Results: Immunohistochemistry for survivin and P-glycoprotein revealed positive staining in 7 (15.4%) and 36 (79.5%) of the 45 tumors, respectively. The mean Ki-67 proliferative index was 43.75 +/- 25.30%. The mean apoptotic index evaluated with the TUNEL method was 37.12 +/- 34.55% for the whole group. We found no significant association between apoptotic index, expressions of survivin and P-glycoprotein, and clinicopathologic variables and survival.
Conclusions: Apoptotic activity, survivin, and P-glycoprotein expression failed to predict the disease extent and biologic behavior in pancreatic adenocarcinoma in our cases.