Anja Wild

p16INK4a is a Prognostic Marker in Resected Ductal Pancreatic Cancer: An Analysis of p16INK4a, p53, MDM2, an Rb

ObjectiveTo 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 DataThe 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. MethodsSixty-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. ResultsSignificantly 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. ConclusionsThe 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.

Low Frequency of p16INK4a Alterations in Insulinomas

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.

Tumor-suppressing pathways in cystic pancreatic tumors.

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.

Prevalence of multiple endocrine neoplasia type 1 in young patients with apparently sporadic primary hyperparathyroidism or pancreaticoduodenal endocrine tumours.

The appropriate treatment for a sporadic endocrine tumour 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.

Multiple endokrine Neoplasie Typ 1

ZusammenfassungDer 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.AbstractPrimary hyperparathyroidism (pHPT) occurs in about 90% of patients with multiple endocrine neoplasia type 1 (MEN1). In contrast to sporadic pHPT, multiple gland disease is most common in MEN1. The appropriate surgical approach is still controversial. The aim of this study was to analyze the results of surgical therapy of pHPT in patients with genetically confirmed MEN1. In an observational study, preoperative data, operative procedures, long-term results, and a possible genotype-phenotype correlation were analyzed in patients with pHPT and genetically confirmed MEN1. According to our results, tPTX+T (total parathyroidectomy+thymectomy+autotransplantation) seems to be a more favorable surgical approach in patients with MEN1 pHPT than sDE (selective gland exstirpation) and stPTX (subtotal parathyroidectromy) without cervical thymectomy, because recurrences or persistence of the disease are rare. A prospective randomized trial is needed to compare stPTX including cervical thymectomy vs tPTX+T. A genotype-phenotype correlation could not be identified.

Multiple endocrine neoplasia type 1. Surgical therapy of primary hyperparathyroidism

ZusammenfassungDer 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.AbstractPrimary hyperparathyroidism (pHPT) occurs in about 90% of patients with multiple endocrine neoplasia type 1 (MEN1). In contrast to sporadic pHPT, multiple gland disease is most common in MEN1. The appropriate surgical approach is still controversial. The aim of this study was to analyze the results of surgical therapy of pHPT in patients with genetically confirmed MEN1. In an observational study, preoperative data, operative procedures, long-term results, and a possible genotype-phenotype correlation were analyzed in patients with pHPT and genetically confirmed MEN1. According to our results, tPTX+T (total parathyroidectomy+thymectomy+autotransplantation) seems to be a more favorable surgical approach in patients with MEN1 pHPT than sDE (selective gland exstirpation) and stPTX (subtotal parathyroidectromy) without cervical thymectomy, because recurrences or persistence of the disease are rare. A prospective randomized trial is needed to compare stPTX including cervical thymectomy vs tPTX+T. A genotype-phenotype correlation could not be identified.

Predictive Genetic Screening and Clinical Findings in Multiple Endocrine Neoplasia Type I Families

Abstract. 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 as an indicator for p16INK4a germline mutations in pancreatic cancer patients

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.

Ergebnisse der chirurgischen Therapie des primären Hyperparathyreoidismus bei Patienten mit Multipler Endokriner Neoplasie Typ 1

Einleitung: Der primare 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 uberprufen. Methoden: Bei unseren Patienten mit nachgewiesener MEN1 -Keimbahnmutation und pHPT wurden Daten zum Verlauf prospektiv bei regelmasigen 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 durchgefuhrt, 2 Patienten lehnten bisher eine Operation ab. Als Ersteingriff wurden 12 selektive Drusenextirpationen (sDE), 3 subtotale (3,5 Drusen) Parathyreoidektomien (sPTX) und 13 totale Parathyreoidektomien mit cervicaler Thymektomie und Autotransplantation von Nebenschilddrusengewebe in den Unterarm (PTX + T) vorgenommen.