EXPRESSION OF P53 PROTEIN IN PANCREATIC ADENOCARCINOMA - RELATIONSHIPTO CIGARETTE-SMOKING

We studied the expression of p53 gene product in pancreatic adenocarci nomas of the usual ductal type to determine its relationship to cigare t smoking and its usefulness as an independent prognostic indicator. T wenty-six resection specimens of pancreatic adenocarcinoma were examin ed by immunohistochemistry using an antigen retrieval solution and mon oclonal PAb 1801 and polyclonal CM1 antibodies on paraffin-embedded ma terial. Specific nuclear p53 expression for both PAb1801 and CM1 was i dentified in seven cases (27%). In all cases immunoreaction was confin ed to neoplastic cells. Three of four (75%) tumors from patients who h ad never smoked showed immunoreaction, whereas only three of 14 (21%) tumors from smokers showed-positive staining. Cases with positive stai ning had shorter mean survival (6.3 mo) than cases that failed to stai n (9.8 mo), but the difference was not statistically significant in th is small study. There was no statistically significant association bet ween p53 immunoreactivity and other clinicopathologic parameters. Our findings indicate that abnormalities of p53 gene in pancreatic adenoca rcinomas may not be directly related to cigaret smoking. Those patient s who survived the longest tended to have tumors negative for p53 immu nostaining. p53 immunoreaction may be a useful feature in distinguishi ng adenocarcinoma from chronic pancreatitis in small biopsies.