We conclude that sporadic gastrinomas at multiple sites are monoclonal and that MEN1 gene alterations in gastrinomas occur before the development of tumor metastases.
To assess whether the MEN1 region is involved in tumour initiation and progression, we analysed 23 primary cutaneous melanomas and 17 metastases for loss of heterozygosity (LOH) using two informative polymorphic markers closely linked to the MEN1 gene (PYGM and D11S449).
We used tissue microdissection to analyze 95 archival pancreatic and duodenal ETs and metastases from 50 patients for loss of heterozygosity (LOH) on 11q13 with 10 polymorphic markers spanning the area of the putative MEN1 gene.
In patients with ZES, increased PP levels were not related to the presence of MEAI or metastases; nor was there a correlation between serum PP and gastrin concentrations.