LOW FREQUENCY OF MICROSATELLITE INSTABILITY
AMONG EUROPEAN PATIENTS WITH PANCREATIC CANCER
Antonino Spinelli1, Anna Brecht2, Gianluca Basso1, Paolo Bianchi1, Guido Schumacher2, Christoph Röcken3, Ilona Gräntzdörffer3, Massimo Roncalli4,5, Peter
Neuhaus2, Marco Montorsi1,6, Luigi Laghi1, Alberto Malesci1,7
Depts. of Gastroenterology, IRCCS-Istituto Clinico Humanitas, Rozzano
Depts. of General Surgery and Trasplantation, Charitè Campus Virchow, University of Berlin
3
Depts. of Pathology, Charitè Campus Virchow, University of Berlin
4
Depts. of Pathology, IRCCS-Istituto Clinico Humanitas, Rozzano
5
Depts. of Pathology, University of Milan
6
Depts. of Surgery, University of Milan
7
Depts. of Internal Medicine, University of Milan
1
2
ABSTRACT
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Background: Inherited and acquired defects of the mismatch repair (MMR)
genes are responsable for gastrointestinal cancers with microsatellite instability (MSI), which account for 10-15% of the cases. However, the reported prevalence of the MSI phenotype among pancreatic tumors varies widely from
1% to 10%, and the contribution to the inherited burden of pancreatic tumors
remains to be determined. AIM. To assess the prevalence of tumors with the
MSI phenotype among pancreatic neoplasms in Caucasian patients.
Materials and methods: We studied the prevalence of the MSI phenotype
among 135 consecutive pancreatic tumor resections performed at an Italian
and at a German referral center. Speci mens from Italy comprised 10 ampullary cancers, 6 endocrine tumors and 57 pancreatic ductal adenocarcinoma
(PDAC), and those from Germany 62 PDAC. MS-status was determined by taking advantage of mononucleotide repeat markers (BAT25 and BAT26), which
are almost monomorphic in Caucasians.
Results: Only one out 119 (0.8%) PDAC showed MSI, and was identified in a
77 years old Italian patient (1.7%), as compared to 1 out 10 ampullary cancers
(10%, P=0.2) arising in a member of a family diagnosed with Hereditary NonPolyposis Colorectal Cancer (HNPCC) due to germ-line hMSH2 defect.
Conclusions: The prevalence of MSI was higher in pancreatic tumors other
than PDAC in European patients. In PDAC MSI is a rare phenomenon, which
does not contribute to the burden of pancreatic cancer, while it is encountered in less frequent, susceptible to radical surgery, pancreatic neoplasms
which might arise in the context of HNPCC.
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Atti del congresso - TUMORI EREDITARI: dalla biologia molecolare al trattamento