| 41. |
- Crona, Joakim, et al.
(författare)
-
Somatic Mutations and Genetic Heterogeneity at the CDKN1B Locus in Small Intestinal Neuroendocrine Tumors
- 2015
-
Ingår i: Annals of Surgical Oncology. - : Springer Science and Business Media LLC. - 1068-9265 .- 1534-4681. ; 22, s. 1428-1435
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Until recently, the genetic landscape of small intestinal neuroendocrine tumors (SI-NETs) was limited to recurrent copy number alterations, most commonly a loss on chromosome 18. Intertumor heterogeneity with nonconcordant genotype in paired primary and metastatic lesions also is described, further contributing to the difficulty of unraveling the genetic enigma of SI-NETs. A recent study analyzing 55 SI-NET exomes nominated CDKN1B (p27) as a haploinsufficient tumor suppressor gene.METHODS: This study aimed to determine the frequency of CDKN1B inactivation and to investigate genotype-phenotype correlations. It investigated 362 tumors from 200 patients. All samples were resequenced for mutations in CDKN1B using automated Sanger sequencing. The expression of p27 was investigated in 12 CDKN1B mutant and nine wild type tumors.RESULTS: Some 8.5 % (17/200) of patients had tumors with pathogenic mutations in CDKN1B including 13 insertion deletions, four nonsense variants, and one stop-loss variant. All variants with available nontumoral DNA were classified as somatic. Inter- and intratumor heterogeneity at the CDKN1B locus was detected respectively in six of ten and two of ten patients. Patients with CDKN1B mutated tumors had both heterogeneous disease presentation and diverse prognosis. Expression of the p27 protein did not correlate with CDKN1B mutation status, and no differences in the clinical characteristics between CDKN1B mutated and CDKN1B wild type tumor carriers were found.CONCLUSION: This study corroborates the finding of CDKN1B as a potential haplo-insufficient tumor suppressor gene characterized by inter- and intratumor heterogeneity in SI-NETs.
|
|
| 42. |
- Crona, Joakim, et al.
(författare)
-
Spatiotemporal Heterogeneity Characterizes the Genetic Landscape of Pheochromocytoma and Defines Early Events in Tumorigenesis.
- 2015
-
Ingår i: Clinical Cancer Research. - 1078-0432 .- 1557-3265. ; 21:19, s. 4451-4460
-
Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: Pheochromocytoma and paraganglioma (PPGL) patients display heterogeneity in the clinical presentation and underlying genetic cause. The degree of inter- and intratumor genetic heterogeneity has not yet been defined.EXPERIMENTAL DESIGN: In PPGLs from 94 patients, we analyzed LOH, copy-number variations, and mutation status of SDHA, SDHB, SDHC, SDHD, SDHAF2, VHL, EPAS1, NF1, RET, TMEM127, MAX, and HRAS using high-density SNP array and targeted deep sequencing, respectively. Genetic heterogeneity was determined through (i) bioinformatics analysis of individual samples that estimated absolute purity and ploidy from SNP array data and (ii) comparison of paired tumor samples that allowed reconstruction of phylogenetic trees.RESULTS: Mutations were found in 61% of the tumors and correlated with specific patterns of somatic copy-number aberrations (SCNA) and degree of nontumoral cell admixture. Intratumor genetic heterogeneity was observed in 74 of 136 samples using absolute bioinformatics estimations and in 22 of 24 patients by comparison of paired samples. In addition, a low genetic concordance was observed between paired primary tumors and distant metastases. This allowed for reconstructing the life history of individual tumors, identifying somatic mutations as well as copy-number loss of 3p and 11p (VHL subgroup), 1p (Cluster 2), and 17q (NF1 subgroup) as early events in PPGL tumorigenesis.CONCLUSIONS: Genomic landscapes of PPGL are specific to mutation subtype and characterized by genetic heterogeneity both within and between tumor lesions of the same patient.
|
|
| 43. |
|
|
| 44. |
|
|
| 45. |
- Daskalakis, Kosmas, et al.
(författare)
-
Association of a Prophylactic surgical approach to Stage IV Small Intestinal Neuroendocrine Tumors with Survival.
- 2018
-
Ingår i: JAMA Oncology. - : American Medical Association (AMA). - 2374-2437 .- 2374-2445. ; 4:2, s. 183-189
-
Tidskriftsartikel (refereegranskat)abstract
- Importance: Primary tumor resection and mesenteric lymph node dissection in asymptomatic patients with stage IV Small Intestinal Neuroendocrine Tumors (SI-NETs) is controversial.Objective: To determine whether locoregional surgery performed at diagnosis in asymptomatic SI-NETs patients with distant metastases affects overall survival (OS), morbidity and mortality, length of hospital stay (LOS) and re-operation rates.Design: This investigation was a cohort study of asymptomatic patients with stage IV SI-NET, diagnosed between 1985 and 2015, using the prospective Uppsala database of SI-NETs and the Swedish National Patient Register. Patients included were followed until May 2016 and divided to a first group, which underwent Prophylactic Upfront Surgery within six months from diagnosis Combined with Oncological treatment (PUSCO group) and a second group, which was either treated non-surgically or operated later (Delayed Surgery As Needed Combined with Oncological treatment [DSANCO group]).Setting: A tertiary referral center with follow-up data from the Swedish National Patient Register.Participants: We included 363 stage IV SI-NET patients without any abdominal symptoms within 6 months from diagnosis, treated either with PUSCO (n=161) or DSANCO (n=202).Exposure: PUSCO vs DSANCO.Main Outcomes and Measures: Overall survival (OS), length of hospital stay (LOS), postoperative morbidity and mortality and re-operation rates measured from baseline. Propensity score match was performed between the two groups.Results: Two isonumerical groups (n=91) occurred after propensity score matching. There was no difference between groups in OS (PUSCO median 7.9 vs DSANCO 7.6 years; [hazard ratio] HR, 0.98; [95% CI, 0.70-1.37]; log-rank P=.93) and cancer-specific survival (median 7.7 vs 7.6 years, HR, 0.99; [95%CI, 0.71-1.40]; log-rank P=.99). There was no difference in 30-day mortality (0% in both matched groups) or postoperative morbidity (2% vs 1%; P>.99), LOS (median 73 vs 76 days; P=.64), LOS due to local tumor-related symptoms (median 7 vs 11.5 days; P=.81) or incisional hernia repairs (4% in both groups; P>.99). Patients from the PUSCO group underwent more re-operative procedures (14%) compared to the DSANCO group (3%) due to intestinal obstruction (P< .001).Conclusion: Prophylactic upfront locoregional surgery confers no survival advantage in asymptomatic stage IV SI-NET patients. Delayed surgery as needed seems to be comparable in all examined outcomes, whilst offering the advantage of less re-operations for intestinal obstruction. The value of a priori locoregional surgery in the presence of distant metastases is challenged and needs to be elucidated in a randomized controlled study.
|
|
| 46. |
- Daskalakis, Kosmas, et al.
(författare)
-
Clinical signs of fibrosis in small intestinal neuroendocrine tumours
- 2017
-
Ingår i: British Journal of Surgery. - : John Wiley & Sons. - 0007-1323 .- 1365-2168. ; 104:1, s. 69-75
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: In patients with small intestinal neuroendocrine tumours (SI-NETs), serotonin and other cytokines released from tumour cells may induce fibrosis, leading to carcinoid heart disease and abdominal fibrotic reactions. The aim of this study was to assess the prevalence, clinical complications and management of this reaction in the abdomen.METHODS: This was a retrospective cohort study of patients with SI-NETs diagnosed between 1985 and 2015. Clinical data, outcomes, radiological findings, and surgical and radiological interventions were reviewed.RESULTS: A total of 824 patients were diagnosed with SI-NETs in the study interval. Clinically significant abdominal signs and symptoms of fibrosis occurred in 36 patients. Of these, 20 had critically symptomatic central mesenteric fibrosis causing obstruction of mesenteric vessels, and 16 had retroperitoneal fibrosis causing obstructive uropathy with hydronephrosis. Extensive fibrosis causing mesenteric vessel obstruction and/or obstructive uropathy was more often associated with symptomatic and advanced disease encompassing lymph node metastases in the mesenteric root, para-aortic lymph node metastases, as well as liver metastases and peritoneal carcinomatosis. Palliative intervention in terms of superior mesenteric vein stenting or resection of central mesenteric metastases and/or percutaneous nephrostomy and J stent treatment was beneficial in the majority of the patients.CONCLUSION: Extensive abdominal fibrosis associated with clinically significant symptoms of intestinal ischaemia and/or obstructive uropathy was linked to advanced disease in patients with SI-NETs. Prompt recognition and minimally invasive intervention was effective in disease palliation.
|
|
| 47. |
|
|
| 48. |
- Daskalakis, Kosmas
(författare)
-
Small Intestinal Neuroendocrine Tumors : Clinical Studies, Novel Serum Biomarkers and Sensitivity to Cytotoxic and Targeted Agents
- 2017
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Small Intestinal Neuroendocrine Tumors (SI-NETs) are indolent neoplasms with an increasing annual incidence of approximately 1/100 000 people. They are often diagnosed at a late stage, restricting treatment efficacy. The aim of this thesis was to investigate clinical aspects of patients with advanced and/or disseminated disease with regard to clinical signs and management of abdominal fibrosis, the role of locoregional surgery and liver transplantation, as well as the ex vivo sensitivity of tumor samples to cytotoxic and targeted agents. Additionally, novel serum biomarkers for the diagnosis and prognosis of SI-NETs were investigated. In Paper I, abdominal fibrosis induced by serotonin and other cytokines from tumor cells, was associated with clinically significant symptoms of intestinal ischemia and/or obstructive uropathy, and was linked to advanced disease. Prompt recognition and minimally invasive intervention with superior mesenteric vein stenting and/or percutaneous nephrostomy and J stent treatment were effective in disease palliation. Paper II challenged the role of prophylactic, upfront locoregional surgery in Stage IV, which conferred no survival advantage in asymptomatic SI-NET patients. The option of delayed surgery as needed seemed to be comparable in all the outcomes examined, whilst also offering the advantage of fewer re-operations for intestinal obstruction in patients with already disseminated disease. Paper III confirmed that most young patients (<65 years) with SI-NET and liver metastases had a favorable survival with standardized multimodality treatment and that survival figures reported after liver transplantation for NETs do not surpass these figures. In Paper IV, 145 biomarkers were analyzed in blood serum using two different multiplex proximity assays. Subsequent ELISA and immunohistochemical analyses identified DcR3, TFF3 and midkine as novel serum biomarkers for SI-NETs. In Paper V, SI-NET samples were profiled with respect to sensitivity ex vivo to a panel of standard chemotherapeutics and targeted agents using a short-term total cell kill assay. SI-NETs exhibited variable but generally intermediate sensitivity ex vivo compared with other cancer diagnoses, calling for individualized selection of therapy.
|
|
| 49. |
- Delgado Verdugo, Alberto, et al.
(författare)
-
Global DNA methylation patterns in small intestinal neuroendocrine tumors (SI-NETs)
- 2014
-
Ingår i: Endocrine-Related Cancer. - 1351-0088 .- 1479-6821. ; 21:1, s. L5-L7
-
Tidskriftsartikel (refereegranskat)abstract
- Small intestinal neuroendocrine tumors (SI-NETs) are rare hormone producing tumors and are often diagnosed at advanced stage. The genetic and epigenetic background of SI-NETs are poorly understood, but several reports have indicated chromosomal losses at 18.21-qter and 11q22-q23. The aim of this study was to characterize CpG DNA methylation status of primary SI-NETs and the corresponding lymph node metastases. We used the commercially available HumanMethylation27 Beadchip array (Illumina), which covers 27578 CpG sites spanning over 14495 genes, and analyzed a discovery cohort of 10 primary SI-NETs with matched metastases. Messenger- mRNA, were determined for selected genes in a 47 tumors. In comparison to the primary tumors, the metastases showed 2697 statistically significant differentially genes. Metastases were generally less methylated than primary tumors. The relative mRNA expression level of the differentially methylated genes AXL, CRMP1, FGF5, and APOBEC3C largely reflected the methylation status. MAPK4, RUNX3, TP73, CCND1, CHFR, AHRR, and Rb1 known to be hypermethylated in other cancer types, displayed overall high methylation level (β-value ≥ 0.9). Methylation (β -value >0,7) at 18q21-qter and 11q22-q23 were detected in genes SETBP1, ELAC1, MBD1, MAPK4, TCEB3C and ARVC1, MMP8, BTG4, APOA1, FAM89B, HSPB1, respectively. Furthermore unsupervised clustering of the tumors identified three distinct clusters, one with a highly malignant behavior. Our data supports involvement of CpG DNA methylation in metastatic progression of SI-NETs and this could present a possibility to identify more aggressive tumors based on DNA methylation.
|
|
| 50. |
- Dumanski, Jan P., et al.
(författare)
-
A MUTYH germline mutation is associated with small intestinal neuroendocrine tumors
- 2017
-
Ingår i: Endocrine-Related Cancer. - 1351-0088 .- 1479-6821. ; 24:8, s. 427-443
-
Tidskriftsartikel (refereegranskat)abstract
- The genetics behind predisposition to small intestinal neuroendocrine tumors (SI-NETs) is largely unknown, but there is growing awareness of a familial form of the disease. We aimed to identify germline mutations involved in the carcinogenesis of SI-NETs. The strategy included next-generation sequencing of exome- and/or whole-genome of blood DNA, and in selected cases, tumor DNA, from 24 patients from 15 families with the history of SI-NETs. We identified seven candidate mutations in six genes that were further studied using 215 sporadic SI-NET patients. The result was compared with the frequency of the candidate mutations in three control cohorts with a total of 35,688 subjects. A heterozygous variant causing an amino acid substitution p.(Gly396Asp) in the MutY DNA glycosylase gene (MUTYH) was significantly enriched in SI-NET patients (minor allele frequencies 0.013 and 0.003 for patients and controls respectively) and resulted in odds ratio of 5.09 (95% confidence interval 1.56-14.74; P value = 0.0038). We also found a statistically significant difference in age at diagnosis between familial and sporadic SI-NETs. MUTYH is involved in the protection of DNA from mutations caused by oxidative stress. The inactivation of this gene leads to specific increase of G:C- > T:A transversions in DNA sequence and has been shown to cause various cancers in humans and experimental animals. Our results suggest that p.(Gly396Asp) in MUTYH, and potentially other mutations in additional members of the same DNA excision-repair pathway (such as the OGG1 gene) might be involved in driving the tumorigenesis leading to familial and sporadic SI-NETs.
|
|
