Naris Nilubol

Prospective Study of 68Ga-DOTATATE Positron Emission Tomography/Computed Tomography for Detecting Gastro-Entero-Pancreatic Neuroendocrine Tumors and Unknown Primary Sites

PURPOSE Gastro-entero-pancreatic neuroendocrine tumors (GEPNETs) are increasing in incidence, and accurate staging is important for selecting the appropriate treatment. (68)Ga-DOTATATE imaging is a promising approach for detecting GEPNETs and could help in selecting optimal therapeutic strategies. The aim of this study was to prospectively determine the clinical utility of (68)Ga-DOTATATE positron emission tomography (PET)/computed tomography (CT) in detecting unknown primary and metastatic GEPNETs. PATIENTS AND METHODS One hundred thirty-one patients were enrolled in a prospective study of patients undergoing (68)Ga-DOTATATE PET/CT, (111)In-pentetreotide single-photon emission computed tomography (SPECT)/CT and multiphasic CT scan, and/or magnetic resonance imaging in a blinded fashion with comprehensive biochemical testing. The primary outcome measure was the detection of lesions by each imaging study. RESULTS (68)Ga-DOTATATE PET/CT imaging detected 95.1% of lesions (95% CI, 92.4% to 96.8%) with an average maximum standardized uptake value of 65.4 ± 47 (range, 6.9 to 244), anatomic imaging detected 45.3% of lesions (95% CI, 37.9% to 52.9%), and (111)In-pentetreotide SPECT/CT detected 30.9% of lesions (95% CI, 25.0% to 37.5%), with a significant difference between imaging modalities (P < .001). In four of 14 patients (28.6%), (68)Ga-DOTATATE PET/CT found a previously unknown primary tumor, and detected primary GEPNET, lymph node, and distant metastases correctly in 72 of 113 lesions (63.7%) when compared with histopathology, with 22.1% and 38.9% detected by using (111)In-pentetreotide SPECT/CT and anatomic imaging, respectively. On the basis of findings with (68)Ga-DOTATATE PET/CT, 43 of 131 patients (32.8%) had a change in management recommendation. In patients with carcinoid symptoms but negative biochemical testing, (68)Ga-DOTATATE PET/CT detected lesions in 65.2% of patients, 40% of which were detected neither by anatomic imaging nor by (111)In-pentetreotide SPECT/CT. CONCLUSION (68)Ga-DOTATATE PET/CT imaging provides important information for accurate staging of GEPNETs and selection of appropriate treatment interventions even in the absence of biochemical evidence of disease in symptomatic patients.

MiR-34a and miR-483-5p are candidate serum biomarkers for adrenocortical tumors

BACKGROUND Nonfunctioning adrenal incidentalomas are common and many patients undergo adrenalectomy to exclude adrenocortical carcinoma (ACC). Recent studies have shown dysregulated microRNA (miRNA) expression in ACC. The objective of this study was to determine the feasibility and diagnostic accuracy of measuring serum miRNAs in patients with benign and malignant adrenocortical neoplasms. METHOD Five miRNAs were selected from miRNA profiling studies in ACC (miR-let-7d, -34a, -195, -214, and 483-5p). Total miRNA was extracted from serum samples in patients with malignant and benign adrenal neoplasms. miRNAs levels were measured by quantitative reverse transcript polymerase chain reaction and normalized to miR-16. To determine if miRNAs were secreted from ACC cells, we measured miRNA levels in culture. RESULTS Serum samples from 22 patients with cortical adenomas and 17 patients with ACC were analyzed, and all 5 miRNAs were detected. We found greater levels of miR-34a (P = .001) and miR-483-5p (P = .011) in patients with ACC. The area under the receiver operating characteristic curve was 0.81 for miR-34a and 0.74 for miR-438-5p. MiR-34a and miR-483-5p levels in ACC cells were greater in the supernatant at 48 hours compared with intracellular levels. CONCLUSION We show that dysregulated miRNAs in ACC are detectable in human serum samples. MiR-34a and miR-483-5p are candidate serum biomarkers for distinguishing between benign and malignant adrenocortical tumors.

miR-145 suppresses thyroid cancer growth and metastasis and targets AKT3.

The expression and function of miR-145 in thyroid cancer is unknown. We evaluated the expression and function of miR-145 in thyroid cancer and its potential clinical application as a biomarker. We found that the expression of miR-145 is significantly downregulated in thyroid cancer as compared with normal. Overexpression of miR-145 in thyroid cancer cell lines resulted in: decreased cell proliferation, migration, invasion, VEGF secretion, and E-cadherin expression. miR-145 overexpression also inhibited the PI3K/Akt pathway and directly targeted AKT3. In vivo, miR-145 overexpression decreased tumor growth and metastasis in a xenograft mouse model, and VEGF secretion. miR-145 inhibition in normal primary follicular thyroid cells decreased the expression of thyroid cell differentiation markers. Analysis of indeterminate fine-needle aspiration samples showed miR-145 had a 92% negative predictive value for distinguishing benign from malignant thyroid nodules. Circulating miR-145 levels were significantly higher in patients with thyroid cancer and showed a venous gradient. Serum exosome extractions revealed that miR-145 is secreted. Our findings suggest that miR-145 is a master regulator of thyroid cancer growth, mediates its effect through the PI3K/Akt pathway, is secreted by the thyroid cancer cells, and may serve as an adjunct biomarker for thyroid cancer diagnosis.

The microRNA expression changes associated with malignancy and SDHB mutation in pheochromocytoma

Currently, the diagnosis of malignant pheochromocytoma can only be made when there is clinical evidence of metastasis or extensive local invasion. Thus, there is a need for new diagnostic marker(s) to identify tumors with malignant potential. The purpose of this study was to identify microRNAs (miRNAs) that are differentially expressed between benign and malignant pheochromocytomas and assess their diagnostic accuracy. Toward this aim, we analyzed miRNA expression in benign and malignant pheochromocytoma tumor samples using whole genome microarray profiling. Microarray analysis identified eight miRNAs that were significantly differentially expressed between benign and malignant pheochromocytomas. We measured a subset of these miRNAs directly by RT-PCR and found that miR-483-5p, miR-183, and miR-101 had significantly higher expression in malignant tumors as compared to their benign counterparts. Area under the receiver operating curve (AUC) analysis indicated that miR-483-5p, miR-101, and miR-183 could be useful diagnostic markers for distinguishing malignant from benign pheochromocytomas. In addition, these miRNAs could be detected in pheochromocytoma patient serum. Overall our data suggest that misexpression of miR-483-5p, miR-101, and miR-183 is associated with malignant pheochromocytoma.

Resection of primary tumor site is associated with prolonged survival in metastatic nonfunctioning pancreatic neuroendocrine tumors

BACKGROUND Nonfunctioning pancreatic neuroendocrine tumors (NFpNET) present with distant metastases in up to 50% of patients. It is unknown whether removal of the primary tumor in patients with NFpNET and metastases is beneficial. METHODS We used the Surveillance, Epidemiology, and End Results database to identify patients with NFpNET and distant metastases. The primary outcome measure in this study was overall survival. RESULTS We identified 882 patients with metastatic NFpNET who had survival data; 303 (34%) patients had operative removal of their primary tumor of which 243 (80%) were grade I or II. Median survival of patients undergoing resection of the primary site was 65 (95% confidence interval 60-86) versus 10 (8-12) months for those without resection (P < .0001). Patients diagnosed after 2003 (n = 625, 71%) were more likely to undergo an operation than those diagnosed earlier (P = .001). Multivariable analysis showed that a lesser tumor grade (P < .0001), younger age (P < .0001), diagnosis during or after 2003 (P = .0003), tumor site in the body/tail (P = .009), and operative resection of the primary tumor site (P < .0001) were associated with prolonged survival of patients with NFpNET and distant metastases. CONCLUSION This study suggests that resection of the site of the primary NFpNET is associated with greater survival in patients with distant metastases and could therefore be considered as a additional treatment option in this patient population.

Genome-Wide Methylation Patterns in Papillary Thyroid Cancer Are Distinct Based on Histological Subtype and Tumor Genotype

CONTEXT Aberrant DNA methylation is known to be a major factor in oncogenesis and cancer progression, but effects of methylation in papillary thyroid cancer (PTC) are not well defined. OBJECTIVE The objective of the study was to identify altered methylation patterns, which may be associated with PTC disease behavior. DESIGN This study was a genome-wide methylation analysis of PTC. SETTING The study was conducted at the National Institutes of Health Clinical Center. PATIENTS PTC tissue from 51 patients were analyzed and compared with normal thyroid tissue from seven patients. INTERVENTIONS CpG methylation status was assessed using advanced genome-wide methylation bead chips. OUTCOME MEASURES Altered methylation patterns in PTC were analyzed by stage, recurrence, histological subtype of tumor, and tumor genotype. RESULTS PTC is globally hypomethylated compared with normal thyroid with 2837 differentially methylated CpG sites. The follicular variant of PTC demonstrated less differential methylation with only 569 differentially methylated CpG sites. Tumors with mutations in BRAF, RET/PTC, and RAS demonstrated a 3.6-fold increase in the number of differentially methylated sites compared with wild-type tumors. The differentially methylated genes were associated with oncological pathways including cellular movement, growth, and proliferation. CONCLUSION PTC is epigenetically distinct from the follicular variant of PTC and by gene mutation status (BRAF, RET/PTC, and RAS).

miR30a Inhibits LOX Expression and Anaplastic Thyroid Cancer Progression

Anaplastic thyroid cancer (ATC) is one of the most lethal human malignancies, but its genetic drivers remain little understood. In this study, we report losses in expression of the miRNA miR30a, which is downregulated in ATC compared with differentiated thyroid cancer and normal tissue. miR30a downregulation was associated with advanced differentiated thyroid cancer and higher mortality. Mechanistically, we found miR30a decreased cellular invasion and migration, epithelial-mesenchymal transition marker levels, lysyl oxidase (LOX) expression, and metastatic capacity. LOX was identified as a direct target of miR30a that was overexpressed in ATC and associated with advanced differentiated thyroid cancer and higher mortality rate. Consistent with its role in other cancers, we found that LOX inhibited cell proliferation, cellular invasion, and migration and metastasis in vitro and in vivo. Together, our findings establish a critical functional role for miR30a downregulation in mediating LOX upregulation and thyroid cancer progression, with implications for LOX targeting as a rational therapeutic strategy in ATC.

Hyperparathyroidism-jaw tumor syndrome: Results of operative management.

BACKGROUND Hyperparathyroidism-jaw tumor syndrome (HPT-JT) is a rare, autosomal-dominant disease secondary to germline-inactivating mutations of the tumor suppressor gene HRPT2/CDC73. The aim of the present study was to determine the optimal operative approach to parathyroid disease in patients with HPT-JT. METHODS A retrospective analysis of clinical and genetic features, parathyroid operative outcomes, and disease outcomes in 7 unrelated HPT-JT families. RESULTS Seven families had 5 distinct germline HRPT2/CDC73 mutations. Sixteen affected family members (median age, 30.7 years) were diagnosed with primary hyperparathyroidism (PHPT). Fifteen of the 16 patients underwent preoperative tumor localization studies and uncomplicated bilateral neck exploration at initial operation; all were in biochemical remission at most recent follow-up. Of these patients, 31% had multiglandular involvement; 37.5% of the patients developed parathyroid carcinoma (median overall survival, 8.9 years; median follow-up, 7.4 years). Long-term follow-up showed that 20% of patients had recurrent PHPT. CONCLUSION Given the high risk of malignancy and multiglandular involvement in our cohort, we recommend bilateral neck exploration and en bloc resection of parathyroid tumors suspicious for cancer and life-long postoperative follow-up.

Prospective screening in familial nonmedullary thyroid cancer

BACKGROUND Approximately 8% of nonmedullary thyroid cancers are familial. The optimal age for screening in familial nonmedullary thyroid cancer (FNMTC) is unknown. METHODS Kindreds with FNMTC (2 or more first-degree relatives affected) were screened prospectively with thyroid ultrasonography. RESULTS Fifteen kindreds showed an overall prevalence of thyroid nodule(s) ≥5 mm of 44% at screening; 19% in the second generation, and 90% in the generation anterior to the index case. The youngest age of detection was 10 years for thyroid nodules and 18 years for thyroid cancer. Microcalcification of thyroid nodules at screening was associated with a greater risk of cancer (P < .05). Family members diagnosed with thyroid cancer by ultrasonographic screening were diagnosed at a younger age and had a lower rate of extra thyroidal invasion (P < .05). CONCLUSION In FNMTC, first-degree relatives 10 years or older, including the generation anterior to the index case, should have thyroid screening by ultrasonography, which may result in earlier diagnosis.

Response after Surgical Resection of Metastatic Pheochromocytoma and Paraganglioma: Can Postoperative Biochemical Remission Be Predicted?

BACKGROUND Aggressive surgical resection with intent to cure and surgical debulking procedures are commonly recommended in patients with metastatic pheochromocytoma and paraganglioma. To date there are no data on operative outcomes of patients after surgical resection of metastatic pheochromocytoma and paraganglioma to determine if such an approach is appropriate and what factors may be associated with a favorable outcome. STUDY DESIGN We performed a retrospective analysis of 30 patients with metastatic pheochromocytoma/paraganglioma who underwent surgical treatment. Clinical characteristics and genetic factors were analyzed as predictors of biochemical response to surgery. RESULTS Thirty patients underwent a total of 42 operations, with a median follow-up time of 24 months (range 1 to 114 months). Complete disease resection (R0/R1) was achieved in 18 (42.9%) cases; 24 cases (57.1%) were debulking (R2) procedures without intent to cure. Complete biochemical remission was achieved in 10 (23.8%) cases and partial biochemical response was achieved in 23 (54.8%) cases. Patients with disease confined to the abdomen were more likely to achieve and maintain a biochemical response postoperatively than those with extra-abdominal disease (p = 0.0003). Debulking operations were significantly less likely to achieve or maintain biochemical palliation, with only 1 patient maintaining a biochemical response 12 months postoperatively (p < 0.0001). Patients were less likely to obtain pharmacologic independence after debulking (p = 0.0003), with only 2 (8.3%) not requiring pharmacotherapy 6 months after the intervention. Factors not associated with biochemical response to surgery include sex, family history, SDHB mutation status, systemic therapy, and preoperative biochemical profile. CONCLUSIONS Depending on the extent of disease, patients with metastatic pheochromocytoma/paraganglioma can benefit from aggressive operative intervention and resection with intent to cure. Debulking procedures are unlikely to achieve clinically significant biochemical response, with any biochemical response achieved being very short-lived.