BACKGROUND/PURPOSE: In general, @entity5 of the pancreas have a favorable prognosis. However, some invasive @entity189 show a rapid progression and a poor prognosis, such as @entity513 of the pancreas. The aim of this study was to clarify the genetic backgrounds underlying the evolution necessary for these @entity5 to become invasive @entity189 . METHODS: Twenty-three @entity1 with @entity5 , including 9 @entity652 , 5 borderline @entity5 , 3 noninvasive @entity189 , and 6 invasive @entity189 , along with 24 @entity1 with @entity513 were studied. After microdissection, @entity984 mutation and loss of heterozygosity (LOH) of the @entity986 and @entity876 genes were investigated. RESULTS: In the @entity5 , @entity984 mutations were frequently seen, without a relationship to histological grade. LOH of the @entity986 gene was observed increasingly with increasing degrees of histological atypia. LOH of the @entity876 gene was seen only in invasive @entity189 . The frequency of each @entity74 in invasive @entity189 was the same as that in @entity513 . The accumulation of genetic alterations was as common in invasive @entity189 , as they were in @entity513 . CONCLUSIONS: The @entity986 and @entity876 gene alterations and accumulations observed are crucial events during the carcinogenesis and malignant progression of @entity5 of the pancreas.

@entity986 and XXXX gene alterations and accumulations in the malignant evolution of @entity5 of the pancreas.

@entity1 :: ('9606', 'Species') :: ['patients'] @entity986 :: ('1029', 'Gene') :: ['p16'] @entity5 :: ('MESH:D009369', 'Disease') :: ['intraductal papillary-mucinous tumors', 'tumors'] @entity984 :: ('3845', 'Gene') :: ['K- ras'] @entity189 :: ('MESH:D002277', 'Disease') :: ['carcinomas'] @entity513 :: ('MESH:D044584', 'Disease') :: ['invasive ductal carcinomas'] @entity876 :: ('7157', 'Gene') :: ['p53'] @entity74 :: ('MESH:D030342', 'Disease') :: ['genetic alteration'] @entity652 :: ('MESH:D000236', 'Disease') :: ['adenomas']
@entity876 :: (7157,Gene) :: ['p53']
