Ola Hessman

Chromosome 18 deletions are common events in classical midgut carcinoid tumors.

Classical midgut carcinoids are rare intestinal neuroendocrine tumors that often present with metastases at diagnosis. In contrast to foregut carcinoids, midgut carcinoids are not related to the multiple endocrine neoplasia type 1 syndrome, and the mechanisms involved in their tumorigenesis are unknown. Eight classical midgut carcinoids were analyzed by genome‐wide screening for loss of heterozygosity. Deletions on chromosome 18 were found in 88% of the tumors. DNA sequencing and immunohistochemical staining for Smad4/DPC4, which often is homozygously mutated in pancreatic and colon carcinomas, revealed no aberrations. In 1 tumor, a region telomeric to the Smad4/DPC4/DCC genes at 18q21 was deleted. Other chromosomes were affected in 3 lesions only. The high frequency of chromosome 18 deletions strongly indicates a genetic alteration of importance in classical midgut carcinoid tumorigenesis, apparently not involving the Smad4/DPC4 gene.

Genetic alterations on 3p, 11q13, and 18q in nonfamilial and MEN 1-associated pancreatic endocrine tumors.

Pancreatic endocrine tumors occur sporadically and as part of the multiple endocrine neoplasia type 1 (MEN 1) and von Hippel‐Lindau (VHL) syndromes. The MEN1 locus on 11q13 and a candidate tumor suppressor locus on 3p are known to be hemi‐ or homozygously mutated in a subset of these tumors. Chromosome arm 18q harbors the SMAD4/DPC4 tumor suppressor gene that is frequently deleted and inactivated in tumors of the exocrine pancreas. We have analyzed 22 nonfamilial and 16 MEN 1‐associated pancreatic endocrine tumors for loss of heterozygosity (LOH) at 3p, 11q13, and 18q. LOH at 3p was revealed in 45% and 36% of tumors from 31 patients with nonfamilial and MEN 1‐associated disease, respectively. The corresponding proportions for 11q13 were 55% and 91%, and for 18q 27% and 25%, respectively. A striking relation between LOH at 11q13 and 3p and a malignant phenotype was found for the nonfamilial tumors. None of the six benign tumors (all of them insulinomas) had allelic loss at 3p or 11q13, whereas 92% (P < 0.01) of the malignant tumors (including malignant insulinomas) had such deletions. Besides the 11q13 abnormality, more than half of the MEN 1‐associated tumors had additional genetic lesions affecting 3p or 18q. LOH analysis of several tumors from two MEN 1 patients suggested different clonal origin of the lesions. Sequencing of the SMAD4/DPC4 gene did not identify mutations in coding regions or at exon/intron boundaries in tumors with LOH at 18q. The data indicate involvement of tumor suppressor genes on 3p and 18q, in addition to the MEN1 gene at 11q13, in the tumorigenesis of both nonfamilial and MEN 1‐associated pancreatic endocrine tumors. Genes Chromosomes Cancer 26:258–264, 1999.

High Success Rate of Parathyroid Reoperation may be Achieved with Improved Localization Diagnosis

IntroductionBecause of the difficulty of reoperative parathyroid surgery, preoperative imaging studies have been increasingly adopted. We report the use of consistently applied localization diagnosis to yield high success rates in parathyroid reoperations.MethodsParathyroid reoperation was performed after previous parathyroid surgery in 144 patients with nonmalignant hyperparathyroidism (HPT) between 1962 and 2007. From the year 2000, 46 patients who underwent parathyroid reoperation and 14 patients who were subjected to thyroid surgery before primary parathyroid operation were investigated with sestamibi scintigraphy (MIBI), 11C-methionine PET/CT (met-PET), surgeon-performed ultrasound (US), US-guided fine-needle aspiration biopsy (US-FNA), and selective venous sampling (SVS) with rapid PTH (Q-PTH) analyses. When imaging was considered adequate, additional studies were generally not obtained.ResultsReversal of hypercalcemia was achieved by reoperation in 134 of 144 (93%) of all patients with previous parathyroid surgery. In patients operated from year 2000, MIBI had 90% sensitivity and 88% predictive value, met-PET 79% sensitivity and 87% predictive value, and US 72% sensitivity and 93% predictive value. SVS with Q-PTH analyses provided accurate localization or regionalization in 11 of 11 recently selected patients. Q-PTH analyses in fine-needle aspirations verified parathyroid origin of excised specimens, and intraoperative Q-PTH helped decide when operations could be terminated. In patients subjected to the algorithm of imaging procedures, reversal of hypercalcemia and apparent cure was obtained after the reoperation in 45 of 46 patients with previous parathyroid surgery, implying a success rate of 98%, and in all patients with previous thyroid surgery.ConclusionsReoperative parathyroid surgery is challenging. Results can be improved by consistently applied sensitive methods of preoperative imaging, and reoperative procedures may then achieve nearly the same success rates as primary operations.

Surgical Treatment of Graves’ Disease: Evidence-Based Approach

BackgroundThe optimal treatment of Graves´ disease (GD) is still controversial. Surgery is one treatment option along with radioactive iodine (RAI) and antithyroid medication. In this evidence-based review, we examine four issues: (1) Is surgery better than RAI or long-term antithyroid medication? (2) What is the recommended surgical approach? (3) How does the presence of Graves’ ophthalmopathy (GO) influence the role of surgery? (4) What is the role of surgery in children with GD?MethodsWe conducted a systematic review of the literature using evidence-based criteria regarding these four issues. Results(1) There are no recommendations reaching any grade of evidence for which treatment to choose for adults with GD. (2) Total thyroidectomy has complication rates equal to those seen with lesser resections but it has higher cure rates and negligible recurrence rates (Level I–IV data leading to a grade A recommendation). (3) Data support surgery when severe GO is present, but RAI combined with glucocorticoids may be equally safe (Level II–IV data, grade B recommendation). The extent of thyroid resection does not influence the outcome of GO (Level II data, grade B recommendation). (4) Based on the available data, definitive treatment can be advocated for children (Level IV data, grade C recommendation) using either RAI or surgery. No recommendation can be given as to whether RAI or surgery is preferred owing to the lack of studies addressing this issue. Increased cancer risk with RAI in children below the age of 5 years supports surgery in this setting (Level I data, grade A recommendation).ConclusionIf surgery is considered for definitive management, evidence-based criteria support total thyroidectomy as the surgical technique of choice for GD. Available evidence also supports surgery in the presence of severe endocrine GO. Children with GD should be treated with an ablative strategy. Whether this is achieved by total thyroidectomy or RAI may still be debatable. Data on long-term cancer risk are missing or conflicting; and until RAI has proven harmless in children, we continue to recommend surgery in this group.

25-Hydroxyvitamin D3 1α-hydroxylase expression in breast cancer and use of non-1α-hydroxylated vitamin D analogue

IntroductionThe cytochrome P450 mitochondrial enzyme 25-hydroxyvitamin D3 1α-hydroxylase (1α-hydroxylase) of renal tubule cells hydroxylates the major circulating form of vitamin D (25(OH)D3) to the active systemic hormone 1,25(OH)2D3. Local production of 1,25(OH)2D3 appears to occur also at other sites where 1α-hydroxylase is expressed for autocrine/paracrine regulation. To reduce risks of hypercalcemia during treatment with vitamin D, we have previously suggested use of non-1α-hydroxylated vitamin D analogues to target tissues where 1α-hydroxylase is expressed, including the parathyroid glands in secondary hyperparathyroidism. The present study was undertaken to examine expression of 1α-hydroxylase in breast cancer and to investigate whether a non-1α-hydroxylated vitamin D analogue displayed biological function. In addition, expression of the 25-hydroxyvitamin D3 24-hydroxylase (24-hydroxylase) and the vitamin D receptor (VDR) was investigated.MethodsThe expression of 1α-hydroxylase, 24-hydroxylase and VDR was investigated in breast cancer specimens (n = 19) and normal breast tissues (n = 10) by immunohistochemistry and/or RT-PCR. Consecutive cryosections of 6 μm essentially free of immune cells were used in the analyses. The effect of vitamin D analogues on transcriptional activation was analyzed in transiently transfected MCF-7 breast cancer cells.Results1α-hydroxylase protein was demonstrated in 79% and 100% of breast cancer specimens and normal breast, respectively. The overall relative mRNA levels of 1α-hydroxylase and 24-hydroxylase in normal breast compared to breast tumors were: 1α-hydroxylase, 1 ± 0.07 versus 0.7 ± 0.05, respectively (p < 0.001); 24-hydroxylase, 1 ± 0.08 verus 2.1 ± 0.2, respectively (p < 0.001). The VDR was expressed in 95% of the tumors as expected, with mRNA levels of 1 ± 0.09 and 1.4 ± 0.12 (p < 0.05) in breast cancer and normal breast, respectively. The ketoconazole-sensitive transcription activation potential of the non-1α-hydroxylated vitamin D analogue prodrug of EB1089 (EB1285) was demonstrated in MCF-7 cells, which express 1α-hydroxylase. The activity of EB1285 was about 20% of 1,25(OH)2D3.ConclusionThese results demonstrate nearly normal expression levels of 1α-hydroxylase, 24-hydroxylase and VDR in the majority of investigated breast cancer specimens. A non-1α-hydroxylated vitamin D analogue displayed activity in breast cancer cells. Such analogues may present future therapeutic options for proliferative disorders where 1α-hydroxylase is expressed.

Upregulated expression of PDGF receptor beta in endocrine pancreatic tumors and metastases compared to normal endocrine pancreas

Platelet-derived growth factor receptor (PDGFR) beta signaling is involved in autocrine growth stimulation of tumor cells, tumor angiogenesis and regulation of tumor interstitial fluid pressure. Development of PDGFR antagonists has further increased the interest for PDGFR as targets for anticancer treatments. Malignant endocrine pancreatic tumors (EPTs) express PDGFR beta both in stroma and on tumor cells. To investigate the role of PDGFR beta signaling in EPTs we compared PDGFR beta expression in normal endocrine pancreas to malignant EPTs and metastases. PDGFR beta expression was examined by immunohistochemistry using specific polyclonal antibodies in ten tissue samples from normal endocrine pancreas, 21 from primary EPTs and 19 from metastases. In eight patients we compared the expression in normal endocrine pancreas to the corresponding primary tumor and metastases, in two patients normal tissue to the primary tumor and in 11 patients primary tumors to the corresponding metastases. Six of ten tissues containing normal pancreas stained negative for PDGFR beta on endocrine cells, while seven of ten stained positive in the stroma. Eighteen of 21 (86%) primary tumors stained positive for PDGFR beta on tumor cells and all had positive stroma stainings. All 19 metastases stained positive for PDGFR beta on tumor cells and in evaluable stroma (n=16). We have found that PDGFR beta is more frequently expressed in primary EPTs and metastases as compared to normal endocrine pancreatic tissue. This is also true for PDGFR beta expression in the corresponding stroma. We suggest that new therapeutic options to inhibit the growth and spread of EPTs could include targeting of PDGFR beta.

Surgical Treatment of Endocrine Pancreatic Tumours

Endocrine pancreatic tumours (EPTs) are uncommon, with a major challenge to alert physicians to their recognition and requirements of treatment. Functioning EPTs cause well-known clinical syndromes of hormone excess. Insulinomas, gastrinomas and glucagonomas are most common; vipomas and somatostatinomas are rare. EPTs also occur as non-functioning lesions without symptoms of hormone excess occasionally with ectopic hormone, such as ACTH and Cushing syndrome as a late complication. The majority of EPTs are sporadic, but they may also be part of a multiple endocrine neoplasia type 1 syndrome or rarely the von Hippel-Lindau syndrome. EPTs have been of great interest to endocrine surgeons and we have, during recent years, witnessed continuing advances in diagnosis, imaging and treatment of the different tumour entities. It has become obvious that surgical treatment of these tumours is of increased concern and can have a marked impact on symptoms and survival.

Parathyroid Glands in Calcium Regulation and Human Disease

Abstract: In humans and other land‐living vertebrates, the parathyroids are known to have an overall regulatory role with action as a thermostat in the systemic calcium homeostasis to ensure tight regulation of serum calcium concentrations and appropriate skeletal mineralization. Parathyroid hormone (PTH) is an 84‐amino‐acid peptide, synthesized and released by parathyroid chief cells in response to hypocalcemia. PTH mobilizes calcium by increasing calcium resorption from bone and by raising calcium reabsorption in the proximal kidney tubule. Treatment with active vitamin D can increase vitamin D receptor expression, inhibit growth of parathyroid tumors, and reduce PTH levels in patients with hyperparathyroidism (HPT). Newly developed vitamin D analogues with reduced calcemic effects and with more pronounced antiproliferative effect may provide new favorable treatment for reversal of HPT.

Recurrent genomic alterations in benign and malignant pheochromocytomas and paragangliomas revealed by whole-genome array comparative genomic hybridization analysis

Pheochromocytomas and abdominal paragangliomas are adrenal and extra-adrenal catecholamine-producing tumours. They arise due to heritable cancer syndromes, or more frequently occur sporadically due to an unknown genetic cause. The majority of cases are benign, but malignant tumours are observed. Previous comparative genomic hybridization (CGH) and loss of heterozygosity studies have shown frequent deletions of chromosome arms 1p, 3q and 22q in pheochromocytomas. We applied high-resolution whole-genome array CGH on 53 benign and malignant pheochromocytomas and paragangliomas to narrow down candidate regions as well as to identify chromosomal alterations more specific to malignant tumours. Minimal overlapping regions (MORs) were identified on 16 chromosomes, with the most frequent MORs of deletion (> or = 32%) occurring on chromosome arms 1p, 3q, 11p/q, 17p and 22q, while the chromosome arms 1q, 7p, 12q and 19p harboured the most common MORs of gain (> or = 14%). The most frequent MORs (61-75%) in the pheochromocytomas were identified at 1p, and the four regions of common losses encompassed 1p36, 1p32-31, 1p22-21 and 1p13. Tumours that did not show 1p loss generally demonstrated aberrations on chromosome 11. Gain of chromosomal material was significantly more frequent among the malignant cases. Moreover, gain at 19q, trisomy 12 and loss at 11q were positively associated with malignant pheochromocytomas, while 1q gain was commonly observed in the malignant paragangliomas. Our study revealed novel and narrow recurrent chromosomal regions of loss and gain at several autosomes, a prerequisite for identifying candidate tumour suppressor genes and oncogenes involved in the development of adrenal and extra-adrenal catecholamine-producing tumours.

Bilateral Adrenalectomy for Ectopic Cushing’s Syndrome—Discussions on Technique and Indication

BackgroundTumors producing adrenocorticotropic hormone (ACTH) or corticotropin releasing hormone (CRH) often remain undiagnosed until severe Cushing’s syndrome appears, and it may be difficult to distinguish from Cushing’s syndrome due to pituitary tumors. Many patients suffer from disease spread, with metastases in the liver or other locations, and the main symptoms may be mineral disturbances, diabetes mellitus, or psychological symptoms from the severe hypercortisolism. Bilateral adrenalectomy may alleviate this situation, but is sometimes a troublesome procedure in these severely ill patients.MethodsWe have retrospectively investigated 8 patients with ectopic Cushing’s syndrome who have undergone bilateral adrenalectomy at the University Hospital in Uppsala. In addition, another 5 patients who underwent bilateral adrenalectomy for other reasons (recurrent pituitary Mb Cushing or bilateral hyperplasia) were scrutinized for technical considerations. Indications, timing of surgery, and operative procedures were studied to identify signs that may support our approach to management in the future.ResultsCurative surgery was not possible in any of the cases with ectopic Cushing’s syndrome. Of the 13 operated patients, handport-assisted laparoscopic adrenalectomy was successfully performed bilaterally in 5 patients and unilaterally in combination with contralateral open surgery in 1 patient; conventional open surgery was performed on 7 patients, 3 of which were conversions from intitial handport-assisted procedures. Non-fatal complications occurred in 4 out of 10 patients.ConclusionsWe conclude that bilateral handport-assisted laparoscopic adrenalectomy is safe, and that all surgical techniques in these severely ill patients may be troublesome and technically demanding. Early surgical intervention may reduce the technical disadvantages. Moreover, bilateral adrenalectomy can substantially reduce the symptoms of Cushing’s syndrome, although effects on mortality are not obvious.