Der primäre Hyperparathyreoidismus (pHPT) tritt bei etwa 90% der Patienten mit multipler endokriner Neoplasie Typ 1 (MEN1) auf. Im Gegensatz zum sporadischen pHPT sind üblicherweise mehrerer Drüsen betroffen. Das geeignete Operationsverfahren ist Gegenstand kontroverser Diskussionen. Ziel der vorliegenden Studie war, die Ergebnisse der chirurgischen Therapie des pHPT bei Patienten mit genetisch gesicherter MEN1 zu analysieren. Hierzu wurden präoperative Befunde, operatives Vorgehen und Therapieergebnisse mit Langzeitverlauf des pHPT sowie mögliche Genotyp-Phänotyp-Korrelationen bei 34 Patienten mit genetisch gesicherter MEN1 im Rahmen einer Beobachtungsstudie analysiert. Nach diesen Ergebnisse scheint tPTX+T (total parathyroidectomy+thymectomy) mit Autotransplantation gegenüber der sDE (selektive Drüsenexstirpation) und der stPTX (subtotal parathyroidectromy) ohne zervikale Thymektomie bei Patienten mit MEN1-pHPT das überlegene Operationsverfahren zu sein, da hierbei Rezidive oder eine Persistenz der Erkrankung selten sind. Zur definitiven Beurteilung ist jedoch ein Vergleich der stPTX mit zervikaler Thymektomie und der tPTX mit zervikaler Thymektomie und Autotransplantation im Rahmen einer prospektiven randomisierten Multicenterstudie erforderlich. Eine Genotyp-Phänotyp-Korrelation wurde nicht gefunden.

Introduction and Aims Serous and mucinous cystic pancreatic tumors have different clinical behavior. We evaluated whether they also have genotypic differences by analyses of the tumor suppressor genes p16INK4a, p53, and DPC4. Methodology Seven serous cystadenomas (SCA) and seven malignant mucinous cystadenocarcinomas (MCC) were analyzed for alterations in the tumor suppressor genes p16INK4a, p53, and DPC4 by single-strand conformational variant analysis, direct sequencing, and immunohistochemical analysis. Methylation-specific polymerase chain reaction analysis was performed to identify p16INK4a promoter hypermethylation. Clinical data were compared with genetic data. Results None of the seven patients with SCAs but five of the seven patients with MCCs died of the tumor after a median follow-up of 44.5 months (range, 4–169 months). All seven MCCs had alterations in at least one tumor suppressor gene compared with none of the seven SCAs. Of the seven MCCs, three had inactivating p16INK4a promoter hypermethylation, five had p53 alterations, and three had DPC4 mutations. Conclusions The tumor suppressor genes p16INK4a, p53, and DPC4 appear to play an important role in the tumorigenesis of MCCs but not SCAs. These molecular data underscore the clinical and histologic differences of serous and mucinous cystic pancreatic tumors.

Molecular mechanisms contributing to the tumorigenesis of pancreatic endocrine tumors (PETs) are still not well understood. Allelic deletions at chromosome 22q12.3 were detected in about 30-60% of PETs, suggesting that inactivation of one or more tumor suppressor genes on this chromosomal arm is important for their pathogenesis. Because the putative tumor suppressor gene tissue inhibitor of metalloproteinase-3 (TIMP-3) has been located at 22q12.3, we undertook a genetic analysis of TIMP-3 to determine its role in the tumorigenesis of PETs. Single-strand conformational polymorphism analysis, methylation-specific PCR, RNA expression analysis, and immunchistochemistry of TIMP-3 were performed in 21 sporadic PETs. Thirteen of 21 PETs (62%) revealed TIMP-3 alterations, including promoter hypermethylation and homozygous deletion. The predominant TIMP-3 alteration was promoter hypermethylation, identified, in 8 of 18 (44%) PETs. It was tumor-specific and corresponded to loss or strong reduction of TIMP-3 protein expression. Notably, 11 of 14 (79%) PETs with metastases had TIMP-3 alterations, compared with only 1 of 7 (14%) PETs without metastases (P < 0.02). These data suggest a possibly important role of TIMP-3 in the tumorigenesis of human PETs, especially in the development of metastases, which has to be further evaluated in large-scale studies.

Background: The appropriate treatment for a sporadic endocrine turnout may be different from those that present as part of the multiple endocrine neoplasia type 1 (MEN1) syndrome. As primary hyperparathyroidism (pHPT) and pancreaticoduodenal endocrine tumours (PETs) are the most common organ manifestations of MEN1, the prevalence of germline mutations in the MEN1 gene was determined in young patients with apparently sporadic pHPT or PETs.Methods: Eighteen of 705 patients with pHPT and 11 of 93 patients with PETs operated on between 1987 and 2001 had no family history of MEN1, only one organ manifestation and were aged 40 years or less at the time of diagnosis. Fifteen patients with pHPT and eight with PETs agreed to MEN1 gene mutation analysis, which was performed by single-strand conformational variant analysis and direct DNA sequencing.Results: Two of 15 patients (13.3 (95 per cent confidence interval (c.i.) 1.6 to 40.4) per cent) with apparently sporadic pHPT had a MEN1 germline mutation. Both mutations were found in patients with pHPT due to multiglandular disease, whereas the remaining 13 patients had a solitary adenoma. None of the eight patients with PETs carried a MEN1 germline mutation.Conclusion: Sporadic pHPT due to multiglandular disease in patients younger than 40 years may represent the first organ manifestation of MEN1 despite a negative family history.

OBJECTIVEA variety of human tumors frequently show allelic deletions of chromosome 22q, suggesting that inactivation of one or more tumor suppressor genes in this region is important for their tumorigenesis.METHODSIn this study, 23 patients with pancreatic endocrine tumors (PETs), including gastrinomas, VIPomas and non-functioning islet cell carcinomas, were analyzed for loss of heterozygosity (LOH) on chromosome 22q with 12 microsatellite and 7 sequence tagged site markers.RESULTSLOH on chromosome 22q was identified in 22 of 23 (96%) PETs. Markers in the chromosomal region 22q12.1 revealed LOH rates up to 85%. Notably, one tumor revealed a homozygous deletion in a second region at 22q12.3. LOH at this locus occurred more frequently in tumors with distant metastases (10 of 11) compared with tumors without distant metastases (3 of 12; P=0.0057) and, overall, allelic loss of 22q is positively correlated with distant metastases (r=0.78; P<0.0001).CONCLUSIONSThese findings are suggestive for novel tumor suppressor gene loci at chromosome 22q that might contribute to the pathogenesis of PETs, especially to the development of distant metastases.

Einleitung: Der primäre Hyperparathyreoidismus (pHPT) tritt bei 80 – 100% der Patienten mit Multipler Endokriner Neoplasie Typ 1 (MEN 1) auf. Die operative Therapie wird kontrovers diskutiert. Ziel der Studie war, die eigenen Ergebnisse bei MEN 1-Patienten zu überprüfen. Methoden: Bei unseren Patienten mit nachgewiesener MEN1 -Keimbahnmutation und pHPT wurden Daten zum Verlauf prospektiv bei regelmäßigen Verlaufs- und Vorsorgeuntersuchungen erfasst (klinischer Befund, Serum-Calcium, Parathormon). Ergebnisse: Von 34 Patienten waren 30 an einem pHPT erkrankt (88%). Das mediane Follow-Up betrug 60 (2 -228) Monate. Insgesamt wurden bei 28 Patienten 40 Operationen durchgeführt, 2 Patienten lehnten bisher eine Operation ab. Als Ersteingriff wurden 12 selektive Drüsenextirpationen (sDE), 3 subtotale (3,5 Drüsen) Parathyreoidektomien (sPTX) und 13 totale Parathyreoidektomien mit cervicaler Thymektomie und Autotransplantation von Nebenschilddrüsengewebe in den Unterarm (PTX + T) vorgenommen.

Objective To identify the prognostic relevance of the G1/S cell cycle regulator genes p16INK4a, p53, MDM2, and Rb in patients with resected ductal pancreatic cancer (PC). Summary Background Data The tumor suppressor genes p16INK4a, p53, and Rb are altered in PC in 27% to 95%, 40% to 70%, and 5%, respectively. The role of MDM2 is not clearly defined in PC. The prognostic value of these cell cycle regulators has not been clarified. Methods Sixty-two patients with PC with complete follow-up who underwent potentially curative resections were included in the study. An extreme group analysis was performed including the 20 patients with the shortest survival and the 20 patients with the longest survival. Protein expression of p16, p53, MDM2, and Rb was investigated, and mutation analysis of p16INK4a and p53 was performed. p16INK4a promoter hypermethylation was examined by methylation-specific polymerase chain reaction. Results Significantly more tumors in the shortest-surviving patients had p16INK4a alterations compared with tumors of the longest-surviving patients. In contrast, the frequency of p53 alterations was not significantly higher in the shortest-surviving versus the longest-surviving groups. Stabilization of MDM2 and loss of Rb expression were identified in a minority of tumors, independent of survival length. Conclusions The presence of p16INK4a alterations in resected tumors of patients with PC is connected with a worse prognosis, indicating patients that might benefit from adjuvant therapy regimens. p53 alterations, MDM2 overexpression, and loss of Rb expression could not be identified as prognostic markers from this study, but a larger study with greater statistical power might show a different result with regard to p53.

The molecular mechanisms contributing to the tumorigenesis of insulinomas are still poorly understood. As moderate to high rates of LOH have been found on chromosome 22q in gastrinomas, we performed a finer deletion mapping study of chromosome 22q with 8 microsatellite markers in 15 insulinomas (4 malignant and 11 benign). Fourteen of 15 (93%) insulinomas revealed LOH on chromosome 22q, whereas the shortest region of overlap implicated a deletion of approximately 700 kb at 22q12.1-q12.2 with an LOH rate of up to 57% (8 of 14). Although the expressed sequence tag marker A006E25 that is localized in the hSNF5/INI1 gene on 22q11.2 revealed LOH in 50% of informative cases (7 of 14), no alterations in this gene could be identified by single strand conformational polymorphism analysis, direct DNA sequencing, or RNA expression analysis. Remarkably, the four malignant tumors showed a common deleted region between markers D22S345 and D22S1144 compared with none of the 11 benign insulinomas. The observed high frequency of chromosome 22q12 deletions in insulinomas is suggestive for a region compatible with harboring a tumor suppressor gene. The hSNF5/INI1 gene is most likely not the candidate gene, because no alterations could be identified. The distinct pattern of allelic loss identified in this chromosomal region appears to be an attractive candidate marker for further evaluation with regard to the discrimination between benign and malignant insulinomas.

Tumor suppressors that are known to be altered in ductal pancreatic adenocarcinoma (p16 INK4a , TP53 and DPC4) are also identified to be altered in malignant cystic pancreatic tumors in contrast to benign tumors by the present study. Thus alterations of tumor suppressors in cystic pancreatic tumors could be identified as strong indicators of malignancy in the tumor panel of the study.

Background.p16INK4a alterations are considered to be an early event in pancreatic tumorigenesis and have been described in duct lesions adjacent to pancreatic cancers. This study evaluates whether duct lesions in chronic pancreatitis tissues of patients without pancreatic cancer also harbor genetic alterations in the p16INK4a tumor-suppressor gene, and thus represent high-risk precursors for pancreatic cancer. Methods. Tissues were obtained from 20 pancreatic specimens taken from patients operated on for histologically verified chronic pancreatitis. Pancreatic intraductal neoplasias (PanIN) were identified in hematoxylin-and-eosin-stained slides. p16 protein expression was investigated immunohistochemically in all specimens. DNA from PanIN and non-PanIN tissue was analyzed genetically for p16INK4a mutations by single-strand conformation variation analysis and direct sequencing of the encoding region. Additionally, p16INK4a promoter methylation was analyzed by a methylation specific polymerase test. Results. PanIN-1a lesions were identified in 10 of the 20 chronic pancreatitis specimens. Four of these 10 PanIN specimens (40%), but none of the 20 non-PanIN tissues, revealed a loss of p16 expression in immunohistochemistry. The mutational analysis of the p16INK4a gene showed 1 known polymorphism (c.442G > A; A148T) but no mutations. Two of the 10 specimens with PanIN revealed an inactivating hypermethylation of the p16INK4a promoter. Conclusions. This study shows for the first time that p16INK4a alterations can be observed in a considerable number of PanIN1 in chronic pancreatitis tissues not associated with pancreatic cancer. Therefore, p16INK4a alterations, especially promoter methylation, might indicate high-risk precursors in chronic pancreatitis that might progress to cancer. (Surgery 2001;129:490-7.)

Background: Use of a standardized meal stimulation test has been recommended for the early diagnosis of pancreaticoduodenal endocrine tumours (PETs) in patients with multiple endocrine neoplasia type 1 (MEN 1). The diagnostic value of this test was re-evaluated.Methods: In a prospective, controlled trial 58 standardized meal stimulation tests (563 kcal) were performed in 12 patients with MEN 1 and histologically, biochemically and/or radiologically confirmed PETs (group 1), 11 carriers of an MEN 1 mutation with no evidence of PETs (group 2) and in 27 healthy controls (group 3). Serum pancreatic polypeptide (PP) and gastrin concentrations were measured before and during the test meal.Results: Patients in group 1 had significantly higher mean basal serum PP and gastrin concentrations than patients in group 2 and controls (P < 0.05). In all three groups an increase in serum PP was observed after meal stimulation, but there was no significant difference between the groups. No increase in gastrin level was found in any of the groups after meal stimulation.Conclusion: The standardized meal stimulation test does not reliably indicate the presence of PETs in patients with MEN 1, whereas raised basal serum PP and gastrin levels do. The expensive and time-consuming meal test can be excluded from MEN 1 screening programmes.

Germline mutations of the MEN1 gene have been identified as the causative genetic defect of multiple endocrine neoplasia type I (MEN-I), an autosomal dominantly inherited condition. To establish the basis for predictive family screening we evaluated the spectrum of MEN1 gene mutations in MEN-I patients treated at our institution. Relatives at risk were subjected to predictive genetic screening after genetic counseling. Gene carriers were subjected to extensive clinical screening for MEN-I, including biochemical tests for basal hormone concentrations in blood and urine, a standardized meal stimulation test and imaging procedures (ultrasonography, computed tomography, magnetic resonance imaging). Among index patients of 15 independent MEN-I kindreds, 14 heterozygous MEN1 germline mutations were identified by single-strand conformational variant analysis (SSCV) and direct DNA sequence analysis. Of 51 individuals at risk, 26 predictively tested relatives with the wild-type MEN1 gene could be excluded from further screening procedures because they had not inherited the disease. In all previously presumed unaffected relatives with the mutant gene, our extensive clinical screening program revealed at least one manifestation of MEN-I. Furthermore, 22 additional diagnoses could be established in identified MEN-I patients. We show that mutation analysis enables predictive genetic screening for MEN-I families, providing a valuable tool for genetic counseling and clinical management. An extensive clinical screening program focusing on genetically proven individuals at risk allows detection of MEN-I manifestations at an early, asymptomatic stage of the disease. Controlled, prospective studies are now required to prove whether timely appropriate treatment on the basis of predictive screening might help improve disease-related quality of life and prolong life expectancy in MEN-I kindreds.

Multiple primary tumors in pancreatic cancer patients might indicate a genetic predisposition to the development of malignancies. In this study we evaluated whether the mutation rate of the TP53 and p16INK4a genes of pancreatic cancers differs in pancreatic cancer patients with and without multiple primaries. Furthermore, we investigated whether pancreatic cancer patients with multiple primaries carry germline mutations in either p16INK4a, TP53, or BRCA2 tumor suppressor genes to detect a genetic alteration that predisposes to the development of different primaries. Fourteen (23%) of 60 pancreatic cancer patients developed histologically verified additional primaries during their lifetimes. Normal constitutional and tumor DNA of the 14 patients with a positive cancer history, but negative family history, were analyzed for p16INK4a, TP53, and BRCA2 mutations by single-strand conformational variant (SSCV) analysis and direct sequencing. Hypermethylation of the p16INK4a promoter region in pancreatic cancers was identified by methylation-specific polymerase chain reaction (PCR; MSP). Four of 14 pancreatic carcinomas carried somatic intragenic p16INK4a mutations, and another four tumors revealed hypermethylation of the p16INK4a promoter region. Somatic intragenic TP53 mutations were identified in six of 14 tumors. None of the pancreatic cancer patients carried TP53 or BRCA2 germline mutations. In contrast, one of 14 pancreatic cancer patients with multiple primaries carried the p16INK4a mutation A68V in his germline. This mutation was localized in the conserved second ankyrin repeat of p16INK4a and did not occur in 100 control patients. The frequency of somatic TP53 and p16INK4a mutations in pancreatic cancer is similar in patients with and without multiple primaries. TP53 and BRCA2 germline mutations seem not to be significantly associated with the occurrence of multiple primaries in pancreatic cancer patients. However, p16INK4a germline mutations might be causative for tumor development in some pancreatic cancer patients with multiple primaries. The genetic investigation of patients with accumulation of different cancers even without a positive family history may be a new approach for the understanding of the relation of different cancers.

BACKGROUND:The genetic basis of several familial cancers including breast and colon cancers has been identified recently. The occurrence of multiple cancers in one individual is also suggestive of a genetic predisposition. To evaluate inherited predisposition in pancreatic cancer we compared the clinical data of pancreatic cancer patients with and without multiple primaries as well as the frequency of malignancies among their relatives.METHODS:Detailed data on 69 pancreatic cancer patients included survival time and TNM-classification. Index case data were separated into two groups. The first group (group 1) developed only pancreatic cancer during their lifetime, whereas the second group (group 2) developed additional primary tumours. A systematic family history was taken from 59 of these pancreatic cancer patients using a standardized questionnaire. The pancreatic cancers and the multiple primaries of the 59 patients were histologically proven.RESULTS:Of the 69 pancreatic cancer patients, 13 (18.8%) had multiple primaries. Neither the clinical data nor the survival data of the index cases revealed differences between the two groups (all nominal P-values >0.05). In the family history study blood relatives developed a malignancy in 51% (24 of 47) of the families in group 1 compared to 75% (9 of 12) in group 2. The risk of relatives in group 2 of developing a malignant tumour was significantly higher (P = 0.034) than in group 1 after adjustments for family size and age of disease onset of the index case. The cancer spectrum of the 59 families mainly included tumours of the digestive tract and the reproductive organs.CONCLUSIONS:A multiple primary cancer history is a common condition among pancreatic cancer patients. Relatives of these patients seem to have an increased risk for the development of distinct malignant solid tumours, which might be caused by an inherited predisposition. Clinical and genetic investigation of pancreatic cancer patients with multiple primaries and their families might lead to the identification of predisposing gene defects providing a new goal for the understanding of a shared genetic basis of different solid tumours.

Background/Aims: The molecular mechanisms contributing to the tumorigenesis of insulinomas are poorly understood. Disruption of the cell cycle due to inactivation of the p16INK4a tumor-suppressor gene was identified in a variety of human tumors, including gastrinomas and nonfunctioning endocrine pancreatic carcinomas. In this study the role of p16INK4a in the tumorigenesis of insulinomas was evaluated. Methods: Seventeen insulinomas (14 benign, 3 malignant) were analyzed for genetic alterations in the p16INK4a tumor-suppressor gene by SSCP, PCR-based deletion and methylation-specific assays. p16 expression was determined by immunohistochemistry. Results: One malignant insulinoma showed a homozygous deletion of p16INK4a and another two benign insulinomas revealed aberrant methylation of the p16INK4a promoter region. All three tumors lacked p16 expression according to immunohistochemistry. None of the insulinomas carried intragenic p16INK4a mutations. In total, 17% of insulinomas had p16INK4a alterations. Conclusions: The p16INK4a tumor-suppressor gene contributes to tumorigenesis in only a small subset of insulinomas.