DEMONSTRATION BY RESTRICTION ENZYME MISMA TCH POLYMERASE CHAIN-REACTION OF POINT MUTATIONS OF THE KI-RAS ONCOGENE IN CARCINOMA OF THE PANCREAS

A pilot study was undertaken to test whether combining the polymerase chain reaction with restriction fragment length polymorphism is suitab le for the routine diagnosis of carcinoma of the pancreas. The method makes it possible to recognize point mutations in codon 12 of the Ki-r as oncogene. 60 cytological specimens from the pancreatobiliary tract, the bronchopulmonary system (by bronchoalveolar lavage or from pleura l effusion) and ascites were tested. Results from nine pancreas carcin oma cell lines served as control. A PCR product was successfully ampli fied in all cell lines and 47 of the clinical specimens. In all eight samples in which a mutated Ki-ras oncogene was demonstrated, there was at least a suspicion of malignancy by cytological examination. A muta tion was also found in four of five pancreas carcinomas. But no mutati on was found in one, clinically certain, case of pancreas carcinoma. T he described method is an elegant and, most of all, rapid means to com plement and optimize any cytological diagnosis.