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Pheochromocytomas (PCC) are catecholamine-producing tumors arising from the adrenal medulla that occur either sporadically or in the context of hereditary cancer syndromes, such as multiple endocrine neoplasia type 2 (MEN2), von Hippel-Lindau disease (VHL), neurofibromatosis type 1, and the PCC-paraganglioma syndrome. Conventional comparative genomic hybridization studies have shown loss of 1p and 3q in the majority of sporadic and MEN2-related PCC, and 3p and 11p loss in VHL-related PCC. The development of a submegabase tiling resolution array enabled us to perform a genome-wide high-resolution analysis of 36 sporadic benign PCC. The results show that there are two distinct patterns of abnormalities in these sporadic PCC, one consisting of loss of 1p with or without concomitant 3q loss in 20/36 cases (56%), the other characterized by loss of 3p with or without concomitant 11p loss in 11/36 (31%). In addition, we found loss of chromosome 22q at high frequency (35%), as well as the novel finding of high frequency chromosome 21q loss (21%). We conclude that there appear to be two subgroups of benign sporadic PCC, one of which has a pattern of chromosomal abnormalities that is comparable with PCC from patients with MEN2 and the other that is comparable with the PCC that arise in patients with VHL disease. In addition, genes on 21q and 22q might play a more important role in PCC pathogenesis than had been assumed thus far. more...

The treatment of choice for non-metastatic pheochromocytoma is surgical resection. Its goals are to abolish catecholamine hypersecretion, normalize blood pressure, and prevent further tumor growth or progression to metastatic disease. Data on long-term mortality and morbidity after pheochromocytoma surgery are limited. We here report a retrospective study on the long-term outcome after surgery for apparently benign pheochromocytoma at the Radboud University Nijmegen Medical Centre. Data on clinical presentation, treatment, post-surgical blood pressure and recurrence, metastasis and death were collected of 69 consecutive patients (January 1966-December 2000; follow-up: until death or January 2006). Survival was compared with survival of a matched reference population. Two patients died of surgical complications. All ten patients with metastatic disease (including three diagnosed at first surgery) died. At follow-up, 40 patients were alive and recurrence free and three patients were lost to follow up. Two patients experienced a benign recurrence. Mean+/-s.d. follow-up was 10.2+/-7.5 (median 9, range 1-38) years. Kaplan-Meier estimates for 5- and 10-year survival since surgery were 85.8% (95% CI: 77.2-94.4%) and 74.2% (95% CI: 62.0-86.4%) for patients versus 95.5 and 89.4% in the reference population (P<0.05). Sixty-four percent of all patients with hypertension prior to surgery showed a significant decrease in blood pressure, but remained hypertensive after surgery. In conclusion, compared with the general population patients have a reduced life expectancy following pheochromocytoma surgery, due to their risk of developing metastatic disease. Only one-third becomes normotensive without antihypertensive medication. Therefore, lifelong follow-up is warranted. more...

The clinical behavior of endocrine pancreatic tumors (EPTs) is difficult to predict in the absence of metastases or invasion to adjacent organs. Several markers have been indicated as potential predictors of metastatic disease, such as tumor size > or =2 cm, Ki67 proliferative index > or =2%, cytokeratin (CK) 19 status, and recently in insulinomas, chromosomal instability (CIN). The goal of this study was to evaluate the value of these markers, and in particular of the CIN, to predict tumor recurrence or progression and tumor-specific death, using a series of 47 insulinomas and 24 non-insulinoma EPTs. From these EPT cases, a genomic profile has been generated and follow-up data have been obtained. The proliferative index has been determined in 68 tumors and a CK19 expression pattern in 50 tumors. Results are statistically analyzed using Kaplan-Meier plots and the log-rank statistic. General CIN, as well as specific chromosomal alterations such as 3p and 6q loss and 12q gain, turned out to be the most powerful indicators for poor tumor-free survival (P< or =0.0004) and tumor-specific death (P< or =0.0113) in insulinomas. The CIN, chromosome 7q gain, and a proliferative index > or =2% were reliable in predicting a poor tumor-free survival in non-insulinoma EPTs (P< or =0.0181, whereas CK19 expression was the most optimal predictor of tumor-specific death in these tumors. In conclusion, DNA copy number status is the most sensitive and efficient marker of adverse clinical outcome in insulinomas and of potential interest in non-insulinoma EPTs. As a consequence, this marker should be considered as a prognosticator to improve clinical diagnosis, most practically as a simple multi-target test. more...

Pheochromocytomas (PCCs) are rare tumors that arise from chromaffin tissue in the adrenal medulla, but can also occur in the abdomen outside the adrenals and are then called sympathetic paragangliomas (sPGLs). According to the literature, between 15 and 25% of apparently sporadic adrenal PCC and sPGL are caused by germline mutations in RET, von Hippel-Lindau disease (VHL), succinate dehydrogenase subunit B (SDHB), or subunit D SDHD. However, few studies have addressed the mutationfrequency of these candidate genes in selected subgroups of PCC andsPGL, such as bilateral adrenal PCC or extra-adrenal sPGL, and none have looked at somatic mutations by analyzing tumor tissue. Therefore, we have investigated the occurrence of germline and somatic mutations in RET, VHL, SDHB, and SDHD in comparatively large series of bilateral adrenal PCC (n = 33 patients) and sPGL (n = 26 patients), with the aim of determining the mutation frequency of each of these genes and to establish a genetic testing algorithm. Twenty-one RET, two VHL germline, and one SDHD mutations were found in the patients with bilateral adrenal PCC. In sPGL, one novel SDHB germline and one novel SDHB somatic mutation were observed. In addition, two SDHD germline mutations were found. We conclude that germline RET mutations are predominantly found in bilateral PCC, and that somatic and germline SDHB and SDHD mutations usually occur in sPGL, which has practical consequences for genetic testing algorithms. We suggest that sequential mutation analysis should be directed first at RET, followed by VHL and SDHD for patients with bilateral adrenal PCC at diagnosis, and at SDHB and SDHD for patients with sPGL. more...

Endocrine pancreatic tumors (EPTs) comprise a highly heterogeneous group of tumors with different clinical behavior and genetic makeup. Insulinomas represent the predominant syndromic subtype of EPTs. The metastatic potential of insulinomas can frequently not be predicted using histopathological criteria, and also molecular markers indicating malignant progression are unreliable because of the small number of cases per subtype studied so far. For the identification of reliable indicators of metastatic disease, we investigated 62 sporadic insulinomas (44 benign and 18 tumors with metastases) by means of comparative genomic hybridization (CGH). In addition, the role of MEN1 (multiple endocrine neoplasia type 1) gene mutations was determined to assess specific chromosomal alterations associated with dysfunction of this endocrine tumor-related tumor suppressor gene. Only one case with a somatic MEN1 mutation was identified (1527del7bp), indicating that the MEN1 gene plays a minor pathogenic role in sporadic insulinomas. CGH analysis revealed that the total number of aberrations per tumor differs strongly between the benign and the malignant group (4.2 vs 14.1; P<0.0001). Furthermore, chromosome 9q gain was found to be the most frequent aberration in both benign and malignant insulinomas, whereas chromosome 6q losses and 12q, 14q and 17pq gains are strongly associated with metastatic disease. Our study shows that chromosomal instability, as defined by > or =5 gains together with > or =5 losses, or total number of gains and losses > or =8, rather than parameters such as tumor size and proliferation index, is the most powerful indicator for the development of metastatic disease in patients with sporadic insulinoma. more...