RARRES2 functions as a tumor suppressor by promoting ß-catenin phosphorylation/degradation and inhibiting p38 phosphorylation in adrenocortical carcinoma.

Tumor suppressor genes and the immune system are critical players in inhibiting cancer initiation and/or progression. However, little is known about whether a tumor suppressor gene can function through both immune-dependent and -independent mechanisms. Retinoic acid receptor responder 2 (RARRES2) is transcriptionally downregulated in multiple cancer types. Previous studies suggested that it can serve as an immune-dependent tumor suppressor by acting as a chemoattractant to recruit anticancer immune cells expressing its receptor, the chemerin chemokine receptor 1 (CMKLR1), to sites of tumor. In this study, we investigated the role of RARRES2 in adrenocortical carcinoma (ACC), a rare lethal malignancy in which aberrant Wnt/ß-catenin signaling is frequently detected. We show that RARRES2 expression is downregulated in ACC as compared with normal and benign adrenocortical tissues, which is a result of CpG hypermethylation. Despite minimal CMKLR1 expression and lack of phenotypic tumor-suppressive effect with exogenous RARRES2 treatment, RARRES2 overexpression in ACC cell lines not only reduced cell proliferation, cell invasion and tumorigenicity in vitro, but also inhibited tumor growth in vivo in two immunodeficient mouse xenograft models. Mechanistically, RARRES2 overexpression in ACC cells inhibited Wnt/ß-catenin pathway activity by promoting ß-catenin phosphorylation and degradation, it also inhibited the phosphorylation of p38 mitogen-activated protein kinase. Thus our study identifies RARRES2 as a novel tumor suppressor for ACC, which can function through an immune-independent mechanism.

Neuroendocrine Tumor of the Pancreas as a Manifestation of Cowden Syndrome: A Case Report.

CONTEXT: Germline mutations in the phosphatase and tensin homolog (PTEN) tumor suppressor gene are found in the majority of patients with Cowden syndrome (CS), who have an increased risk of breast, thyroid, and endometrial cancer. According to our current understanding of genetic changes in the PTEN gene and the resultant phenotypic features of CS, pancreatic neuroendocrine tumors (NETs) are not considered part of the clinical spectrum of CS. CASE DESCRIPTION: We report a unique case of an advanced NET of the pancreas in a patient with CS. The germline DNA sequencing confirmed the clinical diagnosis of CS and revealed a PTEN mutation c.697C→T (p.R233*) causing a premature stop codon in exon 7. The tumor DNA sequencing showed no loss of heterozygosity or any copy number changes and no other deleterious genetic alterations, including those commonly mutated in sporadic pancreatic NETs: MEN1, ATRX, DAXX, TP53, and genes involved in the mammalian target of rapamycin pathway. In addition, the high-throughput transcriptome analyzed by RNA-seq did not reveal any missed genetic alterations, aberrant splicing variants, gene fusions, or gene expression alterations. The immunohistochemical staining of the tumor for PTEN revealed an abnormal, uniformly strong cytoplasmic staining of tumor cells with virtually absent nuclear staining. CONCLUSION: The results from genetic testing and histopathological techniques used to confirm CS diagnosis and characterize this unusual tumor tempted us to believe that in this case, the pancreatic NET was not a sporadic malignancy that occurred by coincidence, but rather represented a new entity in the spectrum of malignancies associated with CS.

Vandetanib successfully controls medullary thyroid cancer-related Cushing syndrome in an adolescent patient.

CONTEXT: Ectopic Cushing syndrome due to ACTH secretion from metastatic medullary thyroid cancer (MTC) is associated with significant morbidity and mortality. OBJECTIVE: The aim of the study was to describe the first case of Cushing syndrome associated with MTC in a pediatric patient and the successful reversal of Cushing syndrome with tyrosine kinase inhibitor (vandetanib) therapy. PATIENT AND METHODS: A 17-year-old Brazilian adolescent presented with metastatic MTC and associated ACTH-dependent ectopic Cushing syndrome in the context of multiple endocrine neoplasia type 2B. When the patient was treated with the tyrosine kinase inhibitor vandetanib, rapid decrease in serum cortisol and improvement of clinical symptoms were observed. CONCLUSION: We describe the first pediatric case of clinical and biochemical improvement of paraneoplastic MTC-related Cushing syndrome after treatment with vandetanib. Vandetanib and possibly other tyrosine kinase inhibitors may be a novel beneficial option in patients with neuroendocrine tumor-related ectopic Cushing syndrome.

Functional thermogenic beige adipogenesis is inducible in human neck fat.

BACKGROUND: Recent studies suggest human neck brown adipose tissue (BAT) to consist of 'brown adipocyte (BA)-like' or beige adipocytes. However, little is known about their thermogenic function. Within the beige adipocyte transcriptome, fibroblast growth factor-21 (FGF21) is a gene whose protein product acts as an adipokine, regulating cold-induced thermogenesis in animals. Here, we explored (i) the adipogenic potential, thermogenic function and FGF21 secretory capacity of beige adipocytes derived from human neck fat and (ii) the role of FGF21 in modulating adipose bioenergetics. METHODS: Progenitors isolated from human cervical fat were differentiated into adipocytes with either a BA-like or white adipocyte (WA) phenotype. FGF21 secretion was measured by enzyme-linked immuosorbent assay. Real-time PCR/western blotting was used to determine cellular mRNA/protein levels. Extracellular flux bioanalyzer was used to quantify adipocyte oxygen consumption and fatty acid oxidation. Adipocyte heat production was measured by infrared thermography. RESULTS: Under hormonal manipulation, primary human neck pre-adipocytes differentiated into adipocytes with either BA-like or WA phenotypes, on gene/protein and functional levels. BA-like cells expressed beige but not classic BA markers. During BA differentiation, FGF21 gene expression and secretion were increased, and were augmented following norepinephrine exposure (a cold mimic in vitro). Differentiated WA expressed ß-klotho, a critical co-factor mediating FGF21 action. Treatment of WA with FGF21-induced UCP1 expression and increased oxygen consumption, respiratory uncoupling, norepinephrine-mediated thermogenesis, fatty acid oxidation and heat production, thus recapitulating the association between cold-induced FGF21 secretion and cold-induced thermogenesis in vivo. CONCLUSION: Beige adipocytes are thermogenic in humans. FGF21 is a beige adipokine capable of promoting a brown fat-like thermogenic program in WAs. SIGNIFICANCE: This study provides first evidence of inducible functional thermogenic beige adipogenesis in human neck fat. FGF21 holds promise as a cold-induced beige adipokine with metabolic benefits of therapeutic relevance through browning of white adipose tissue.

KCNJ5 mutations in the National Institutes of Health cohort of patients with primary hyperaldosteronism: an infrequent genetic cause of Conn's syndrome.

KCNJ5 mutations were recently described in primary hyperaldosteronism (PH or Conn's syndrome). The frequency of these mutations in PH and the way KCNJ5 defects cause disease remain unknown. A total of 53 patients with PH have been seen at the National Institutes of Health over the last 12 years. Their peripheral and tumor DNAs (the latter from 16 that were operated) were screened for KCNJ5 mutations; functional studies on the identified defects were performed after transient transfection. Only two mutations were identified, and both in the tumor DNA only. There were no germline sequencing defects in any of the patients except for known synonymous variants of the KCNJ5 gene. One mutation was the previously described c.G451C alteration; the other was a novel one in the same codon: c.G451A; both lead to the same amino acid substitution (G151R) in the KCNJ5 protein. Functional studies confirmed previous findings that both mutations caused loss of channel selectivity and a positive shift in the reversal potential. In conclusion, the KCNJ5 protein was strongly expressed in the zona glomerulosa of normal adrenal glands but showed variable expression in the aldosterone-producing adenomas with and without mutation. The rate of KCNJ5 mutations among patients with PH and/or their tumors is substantially lower than what was previously reported. The G151R amino acid substitution appears to be the most frequent one so far detected in PH, despite additional nucleotide changes. The mutation causes loss of this potassium channel's selectivity and may assist in the design of new therapies for PH.

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.

Laparoscopic bilateral adrenalectomy: results for 30 consecutive cases.

BACKGROUND: Most patients requiring bilateral adrenalectomy have adrenocorticotropin hormone (ACTH)-dependent Cushing's syndrome. Some of these patients are severely debilitated from the chronic effects of cortisol overproduction. This study aimed to analyze the indications, safety, efficacy, and outcomes for laparoscopic bilateral adrenalectomy from the authors' experience. METHODS: A retrospective review was conducted at a university tertiary referral center. Between March 1996 and August 2006, 30 consecutive patients underwent simultaneous laparoscopic bilateral adrenalectomy. The patient records were analyzed to obtain patient demographics, disease etiology, surgical approach, operating room information, postoperative complications (30 days), hospital length of stay (LOS), and follow-up information. RESULTS: The 30 participants (22 women and 8 men) had a mean age of 44 years. The indications for bilateral adrenalectomy were refractory Cushing's disease (n = 16), occult ectopic ACTH syndrome (n = 9), and bilateral pheochromocytoma (n = 5). A mean of 53 months elapsed between onset of symptoms and adrenalectomy. Laparoscopic bilateral adrenalectomy was completed for all the patients with no intraoperative complications. Four patients (13%) experienced six complications. The mean postoperative LOS was 3.5 days (range, 1-12 days). Seven patients required a preoperative LOS, for a mean of 7.1 days (range, 1-20 days), and a postoperative LOS, for a mean of 5 days (range, 2-12 days). The 23 patients who did not require preoperative hospitalization had a mean postoperative LOS of 3 days (range, 1-7 days). All the patients received postoperative steroid replacement and appropriate follow-up assessment with an endocrinologist. At this writing, the patients with Cushing's syndrome available for follow-up evaluation continue to receive steroid replacement, and all the pheochromocytoma patients have experienced a documented postoperative biochemical cure. CONCLUSIONS: Laparoscopic bilateral adrenalectomy is safe and effective for this high-risk patient population. Although patients should be monitored closely in the postoperative period, most are discharged with glucocorticoid and mineralocorticoid replacement in a short time without complications.

Good blood pressure control on antihypertensives, not only response to spironolactone, predicts improved outcome after adrenalectomy for aldosteronoma.

BACKGROUND: Spironolactone is frequently used before adrenalectomy for hyperaldosteronism to control blood pressure. Response to spironolactone has been suggested to predict a better outcome. However, whether using other antihypertensive medications to control blood pressure predicts outcome remains unknown. We sought to determine the relationship between preoperative normalization of blood pressure with antihypertensive medications and response to adrenalectomy for hyperaldosteronism. METHOD: A retrospective cohort study of 102 patients who underwent adrenalectomy for hyperaldosteronism at a tertiary medical center were included. Blood pressures were measured at first clinical presentation, preoperatively, postoperatively, and at 1 and 6 months postoperatively. The primary outcome measure was complete resolution of hypertension (blood pressure <140/90) without antihypertensive medications, versus incomplete resolution requiring antihypertensive medications. RESULTS: Hypertension resolved and medications were discontinued in 39% of patients. Hypertension resolved without medications in 53% of patients who were normotensive preoperatively versus 24% of patients who were hypertensive (P = .006). In contrast, hypertension resolved without medications in only 45% of patients who were normotensive on spironolactone preoperatively versus 34% of patients who were hypertensive (P = .38). CONCLUSIONS: Patients with good preoperative control of hypertension on antihypertensive medications, irrespective of response to spironolactone, are more likely to have complete resolution.

How to localize parathyroid tumors in primary hyperparathyroidism?

The management of primary hyperparathyroidism (PHPT) has dramatically changed in the last 5 yr. Many more patients now undergo focused, limited or minimally invasive parathyroidectomy instead of traditional bilateral neck exploration. This change has taken place because of the improved accuracy of pre-operative localizing studies in selecting patients who have single-gland parathyroid disease (single adenoma) and can therefore have a minimally invasive parathyroidectomy. Sestamibi scanning followed by ultrasound, magnetic resonance imaging (MRI) and computed tomography (CT) scans are most accurate for localizing parathyroid tumors in patients with PHPT. Selective venous catheterization for PTH levels is useful when other localizing studies are negative or discordant in patients with persistent or recurrent PHPT. The routine use of one or more localizing studies commonly identifies the parathyroid tumor in patients with single-gland disease; but if localizing studies are negative or discordant, patients should have intra-operative PTH levels monitored or have a bilateral neck exploration to ensure a high rate of biochemical cure.

Selective modified radical neck dissection for papillary thyroid cancer-is level I, II and V dissection always necessary?

BACKGROUND: There is ongoing controversy as to the indications for and extent of lateral cervical lymphadenectomy for patients with papillary thyroid cancer (PTC). While most now agree that prophylactic lymph node dissections (LND) play no role, at the University of California, San Francisco (UCSF) we limit LND selectively on a level by level basis, and resect only the levels thought to harbor disease or to be at increased risk of metastases. This initial 'selective LND' usually includes levels III and IV (due to the well-documented increased likelihood of metastases to these levels) and levels I, II, and V are included when there is clinical or radiological evidence of disease or increased risk of it. METHODS: A retrospective review of the clinical charts and hospital records of 106 consecutive patients who had metastatic PTC and who underwent at least one lateral cervical LND at UCSF between January 1995 and December 2003 was carried out. Data were collected to assess which patients had levels I, II, and/or V included in their initial ipsilateral and/or contralateral LND and to determine the recurrence rates at these levels if they had previously been excised compared with if they had not. Chi-squared and Fisher exact tests were utilized for statistical comparison, where appropriate. RESULTS: A total of 140 initial lateral LND were performed: 104 ipsilateral and 36 contralateral. In these initial LND, 3.9%, 72.5%, and 18.6% of patients had levels I, II, and V resected on the ipsilateral side, and 2.9%, 60.0%, and 37.1% of patients had levels I, II, and V resected on the contralateral side. Recurrence at levels I and V was uncommon in all patient populations. Recurrence at level II was 19% ipsilaterally and 10% contralaterally when the level was previously resected and 21% ipsilaterally and 14% contralaterally when the level was not previously resected. There was no statistically significant difference in recurrence at level II when the level had previously been resected compared with when it had not. CONCLUSIONS: If utilized in the appropriate patient population, a selective approach to lateral cervical LND for PTC can be a successful alternative to the routine modified radical LND. Levels I and V do not require resection unless there is clinical or radiological evidence of disease. Guidelines for which patients may be considered for this less aggressive approach to level II nodal metastases are suggested.

Prognostic scoring systems in patients with follicular thyroid cancer: a comparison of different staging systems in predicting the patient outcome.

BACKGROUND: The use of prognostic scoring systems is important for predicting the survival of individuals with thyroid carcinoma. Relatively few studies have addressed this issue for patients with follicular thyroid cancer. The goal of this retrospective study was to establish the best and most pertinent prognostic scoring system to predict survival in patients with follicular thyroid cancer. METHODS: We selected 86 patients with follicular thyroid cancer treated at University of California, San Francisco (UCSF) hospitals from January 1954 to April 1998. The mean follow-up time was 11.5 years. There were 60 women (70%) and 26 men (30%), with a mean age if 48.6 years. Prognostic scoring systems included tumor, node, metastases (TNM), European Organization for Research and Treatment of Cancer (EORTC), Age, Grade, Extent, Size (AGES), Age, Metastases, Extent, Size (AMES), and the Metastases, Age, Completeness of resection, Invasion, Size (MACIS). Survival time was calculated using the Kaplan-Meier method. Using Cox proportional hazards analysis, the relative importance of each scoring method was determined by calculating the proportion of variation in survival time explained (PVE). RESULTS: Kaplan-Meier analysis indicated that all scoring systems were significant predictors of survival time (p < 0.0001). The PVE associated with each system was (from highest to lowest) 0.48 for MACIS, 0.46 for AGES, 0.44 for EORTC, 0.40 for AMES, and 0.33 for TNM. These results indicate that the MACIS scoring system accounted for a great proportion of explained variance in survival and is a more precise predictor of survival compared to the other scoring systems. CONCLUSIONS: TNM, EORTC, AGES, AMES, and MACIS, all provided useful prognostic information about the survival in our 86 patients with follicular thyroid cancers. The MACIS classification, however, was the most accurate predictor using PVE as a method of evaluation. Future scoring systems considering additional prognostic factors, may obtain a higher PVE.

Intraoperative parathyroid hormone assay and parathyroid reoperations.

BACKGROUND: The purpose of this study was to determine whether intraoperative parathyroid hormone (IOPTH) assay improved results of reoperations. METHODS: One hundred two patients with persistent/recurrent sporadic primary hyperparathyroidism underwent 108 reoperations (1996-2002). IOPTH was not used (n=58) from 1996-1998 (group 1). IOPTH was used (n=50) from 1999-2002 (group 2). Sensitivity and positive predictive value of IOPTH and its influence on surgical strategy were analyzed. A 50% decrease occurring 10 minutes after removal of parathyroid tumor was used to determine if all abnormal tissue had been removed. RESULTS: Groups 1 (58 patients) and 2 (50 patients) were comparable except for duration of follow-up. The cure rate was 84% (group 1, 87%; group 2, 82%, P=0.7). Hypocalcemia developed in 20 patients (permanent in 2 patients). There was 1 permanent vocal cord paralysis and 1 patient died of toxic shock syndrome. IOPTH successfully predicted cure in 44 of 49 patients (sensitivity, 90%); the positive predictive value was 90%. Values for parathyroid hormone level and the ratio parathyroid hormone/calcium at day 1 were at least as accurate as IOPTH in predicting cure. IOPTH was helpful in 1 patient but misleading in 4 patients. It failed to modify intraoperative strategy in most other patients. CONCLUSIONS: IOPTH testing was relatively reliable in patients with persistent or recurrent sporadic primary hyperparathyroidism, but the test unfortunately failed to improve the overall success rate at reoperation.

Localization and reoperation results for persistent and recurrent parathyroid carcinoma.

HYPOTHESIS: Reoperation is safe and benefits patients with persistent and recurrent parathyroid carcinoma. DESIGN: Retrospective study. The mean follow-up time was 8.1 years (median, 7 years; range, 1-23 years). SETTING: A university tertiary referral center. PATIENTS: Eighteen patients treated for parathyroid carcinoma from 1966 to 1999. RESULTS: The mean serum calcium level was 13.7 mg/dL (3.43 mmol/L), and the parathyroid hormone (PTH) level was 1.6 to 20 times the upper limit of normal. Fourteen of 18 patients had persistent or recurrent parathyroid carcinoma and underwent 54 reoperations (28 at our institution). Mean time to recurrence was 4.8 years (range, 1-20 years). Symptoms of hyperparathyroidism were relieved in 86% of patients who had reoperation (P<.05). Reoperation for parathyroid carcinoma (25 locoregional and 3 distant) significantly reduced and normalized the serum calcium and PTH levels in 75% and 62% of the cases, respectively (P<.001). The preoperative serum calcium level was a significant predictor of postreoperative normalization of the serum calcium level but not extent of initial resection, PTH level, time to recurrence, concordance of localization studies, or patient age and sex (P<.01). Surgical complications consisted of 5 unilateral and 1 bilateral permanent recurrent laryngeal nerve palsies (2 intentionally resected en bloc), 1 transient hypoparathyroidism, 1 wound seroma, and 1 tracheoesophageal fistula. The sensitivity rates of sestamibi scan (n = 14), magnetic resonance imaging (n = 15), computed tomographic scan (n = 6), ultrasound (n = 13), and selective venous catheterization with PTH measurement (n = 6) were 79%, 93%, 67%, 69%, and 83%, respectively. CONCLUSIONS: Recurrence is common in patients with parathyroid carcinoma. Patients with this disease should have frequent, lifelong follow-up to ensure early detection of recurrence. Although reoperation for persistent or recurrent parathyroid carcinoma provides significant symptomatic relief and normalizes serum calcium and PTH levels in most patients, it is associated with some morbidity. Localizing studies of parathyroid carcinoma are helpful but do not detect all tumor foci.

Coexisting chronic lymphocytic thyroiditis and papillary thyroid cancer revisited.

The effect of chronic lymphocytic thyroiditis (CLT) on the behavior of papillary thyroid cancer (PTC) remains unclear. In recent studies the presence of CLT in patients with PTC was reported to be associated with a lower recurrence rate and an improved survival rate. Furthermore, patients with PTC and tumor infiltrating lymphocytes (TILs) have been reported to have lower recurrence rates and a lower frequency of distant metastases. Because of these and other observations, a tumor immune response in PTC has been suggested. The aim of our study was to determine: (1) the relative frequency of CLT in PTC; (2) the prognostic significance of CLT in patients with PTC; and (3) if TIL occurs independently or in association with CLT. A 10-year retrospective study of patients who underwent initial thyroidectomy for PTC from 1986 to 1996 was completed. The extent of thyroid lymphocytic infiltration was determined within the tumor, surrounding the tumor, and in the distant parenchyma by two independent observers blinded to the clinical data. Dense focal/diffuse lymphoid aggregates throughout the thyroid gland were diagnostic of CLT and when present within or surrounding the tumor were designated TILs. A total of 136 patients with PTC (typical and follicular variant of PTC histologic subtypes) were identified with a mean follow-up of 4.4 years and a 8% mortality rate at 10 years. Thirty percent of the patients with PTC had coexisting CLT, and 65% of these patients with CLT had positive anti-thyroglobulin antibodies. Patients with coexisting CLT and PTC were younger (p < 0.05), more likely to be female (p < 0.05), and more likely to have multicentric tumors (p < 0.001) compared to patients without CLT. Only 5% of patients had TILs without CLT, but 82.5% of patients with CLT had TILs identified (p < 0.0001). By univariate analysis CLT, age, gender, stage of PTC, tumor multicentricity, and tumor size were significant prognostic factors. Only age and TNM stage of PTC remained independent prognostic factors by multivariate analysis. We found a similar frequency (30%) of coexisting CLT and PTC as reported by others; but, more importantly, the presence of TILs primarily occurred in association with CLT. The presence of CLT in patients with PTC correlated with an improved prognosis. It was not an independent prognostic factor, however, and was not associated with a lower recurrence rate or a lower frequency of distant metastasis.

Laparoscopic adrenalectomy: the optimal surgical approach.

BACKGROUND AND PURPOSE: Laparoscopic adrenalectomy has emerged as the treatment of choice for most adrenal surgical disorders. We describe our experience with 176 laparoscopic operations. PATIENTS AND METHODS: The patients were treated for hyperaldosteronism (N = 62), pheochromocytoma (N = 43), "incidentaloma" (N = 21), Cushing's syndrome (N = 20), suspected adrenal metastasis (N = 16), Cushing's disease (N = 8), adrenal hemorrhage (N = 3), or virilizing tumor (N = 1). In 154 of the 176 laparoscopic operations, a lateral transabdominal approach (15 bilateral, 76 left, and 63 right) was used. In the remaining 22, a posterior laparoscopic approach (3 bilateral, 10 left, and 9 right) was used. RESULTS: The average total operating time for unilateral laparoscopic adrenalectomy was 2.8 hours, and for bilateral adrenalectomy, it was 5.2 hours. The mean tumor size was 4.6 cm (range 1-15 cm). There was no significant difference in operating time according to the tumor size. The average length of hospitalization was 1.7 days (range 1-9 days). The perioperative complication rate was 5.1%. There were no conversions to an open procedure. The operating time, length of hospitalization, and perioperative complication rate were stable over the period. Although we used the posterior laparoscopic approach only for smaller tumors (<6 cm), we found no differences in patient outcome between the lateral and posterior laparoscopic approaches. CONCLUSION: For almost all adrenal surgical disorders, an initial laparoscopic approach is optimal. It is safe and is associated with the best patient outcome.

Parathyroid carcinoma.

Although parathyroid neoplasms are common and cause primary hyperparathyroidism, parathyroid carcinoma is a rare entity. At times it can be difficult to diagnose. Patients with parathyroid carcinoma usually present with profound symptoms of hyperparathyroidism and highly elevated serum calcium and parathyroid hormone (PTH) levels. At the time of neck exploration, a large, gray-white, locally invasive tumor is commonly encountered. The course of patients with parathyroid carcinoma is variable; unfortunately, more than 50% have persistent or recurrent disease due to regional or distant disease. Surgical resection is the principal treatment for patients with parathyroid carcinoma. The optimal surgical treatment is en bloc tumor resection with ipsilateral thyroid lobectomy when the diagnosis is suspected and until it is proven otherwise. Patients who have persistent or recurrent parathyroid carcinoma should have localizing studies to identify loco-regional or distant tumor sites. Reoperation in patients with localized parathyroid carcinoma is recommended because it relieves symptoms of hypercalcemia, and it normalizes serum calcium and PTH levels in most patients. For patients who have unresectable parathyroid carcinoma, a protocol-based treatment with chemotherapy and external radiotherapy should be considered. Additionally, second-generation bisphosphonates and the NPS R-568 calcimimetic agent may be useful in normalizing the serum calcium and improving symptoms of hypercalcemia. However, they do not treat the tumor and are rarely effective in the long term.

The helix-loop-helix transcription factor, Id-1, is overexpressed in medullary thyroid cancer.

BACKGROUND: The Id-1 helix-loop-helix protein inhibits differentiation and enhances cell proliferation. It is required for cell cycle progression. The Id-1 gene is highly expressed in a variety of tumor-derived cell lines. It increases after mitogen stimulation and is overexpressed in some human neoplasms. Therefore, we hypothesized that the Id-1 gene may play a role in medullary thyroid carcinogenesis. METHODS: The expression of the Id-1 protein in human medullary thyroid cancer (MTC) and the corresponding normal thyroid tissue was determined by Id-1 immunohistochemistry. In a human MTC cell line (TT), the effects of growth stimulation and redifferentiation on Id-1 expression were determined by Northern blot analysis. RESULTS: Id-1 immunostaining intensity in 9 MTC samples (6 sporadic, 2 familial, and 1 MEN 2A) was moderate to strong. However, it was absent or faint in the corresponding normal thyroid tissue. The Id-1 protein was significantly overexpressed in MTC compared with corresponding normal thyroid tissue on the basis of the percentage of positive cells and immunostaining intensity (P =.002). In the TT cell line, Id-1 messenger RNA (mRNA) expression was increased 4-fold after growth stimulation with serum. Phorbol ester (which induces redifferentiation in the TT cell line) downregulated Id-1 mRNA expression. CONCLUSIONS: Id-1 is overexpressed in MTC. The Id-1 gene may play a role in the regulation of MTC differentiation and proliferation.

Total thyroidectomy or thyroid lobectomy in patients with low-risk differentiated thyroid cancer: surgical decision analysis of a controversy using a mathematical model.

There is a general consensus that total or near-total thyroidectomy is the optimal treatment for patients with high risk differentiated thyroid cancer (DTC), but the optimal extent of thyroidectomy in patients with low risk DTC continues to be controversial. To determine the optimal extent of thyroidectomy in patients with low risk DTC, we used decision analysis to compare the trade-offs of total thyroidectomy (TT) to thyroid lobectomy (TL). The decision analysis model included the probabilities of thyroidectomy complications, risk of DTC recurrence, and death from DTC. This information was obtained from the literature and from outcome data for patients with low risk DTC from our institution. In addition, the concept of utilities was used in the analysis. To determine the utility of each health outcome state (thyroidectomy complication, DTC recurrence, and DTC mortality for low risk patients) a survey was conducted. Overall, prospective patients viewed DTC recurrence as less desirable than thyroidectomy complication. The utilities assigned by the survey participants varied over a wide range, with 61.5% of the individuals viewing the occurrence of a thyroidectomy complication as better than DTC recurrence. At baseline utilities and probabilities, TT had a higher expected utility than TL. One-way sensitivity analysis varying the rates of (1) thyroidectomy complication, (2) DTC recurrence, and (3) DTC mortality over the possible range showed that complication from initial thyroidectomy was the most important factor that determined the preferred extent of thyroidectomy. TL was the preferred surgical approach only if a complication rate of > 33:1, TT/TL complication rate ratio, was assumed. When no differences in DTC recurrence between the two approaches was assumed in the model, TL had a higher expected utility using the baseline utilities of thyroidectomy complication and DTC mortality. The analysis indicates that TT in patients with low risk DTC is preferable to TL. However, TL is preferred if (1) no difference in the DTC recurrence rate between the two approaches is assumed, (2) a higher complication rate for TT is used (> 33 times higher), or (3) the utility ratio of thyroidectomy complication to DTC recurrence is < 0.8 TL. We believe this decision analysis model provides an objective approach that others can use to select the optimal extent of thyroidectomy based on patient preference of health outcome states, institution-specific outcome data for DTC recurrence or mortality, and the surgeon-specific complication rate.

Long-term results of reoperation and localizing studies in patients with persistent or recurrent medullary thyroid cancer.

HYPOTHESIS: Reoperation benefits patients with locoregional, persistent, or recurrent medullary thyroid cancer (MTC). Currently available localizing studies have limited utility for detecting all foci of residual MTC. DESIGN: A retrospective study with a mean follow-up time of 7.5 years (median, 13 years; range, 2.2-29 years). SETTING: A tertiary referral medical center. PATIENTS: Thirty-three patients who underwent 46 reoperations for locoregional residual MTC. RESULTS: Sixty-four percent of residual MTC was located in the lateral cervical nodes, 22% in the central cervical nodes or thyroid bed, and 14% in the anterior mediastinum (197 of 1128 nodes resected were positive for MTC). After reoperation, basal calcitonin levels were undetectable in 2 patients, reduced by greater than 50% in 10 patients, and either increased or were not reduced by greater than 50% in the remaining patients. On reoperation, one patient had a thoracic duct injury that required reexploration and ligation. Patients who had a greater than 50% decrease in calcitonin levels after reoperation were less likely to develop distant metastases compared with patients who did not have a greater than 50% decrease (P<.05). The sensitivities of magnetic resonance imaging (n = 31), computed tomographic scan (n = 16), ultrasound (n = 9), and dimercaptosuccinic acid scan (n = 3) were 91%, 86%, 88%, and 100%, respectively. CONCLUSIONS: Although reoperation in patients with residual MTC rarely results in biochemical cure, cervical reexploration is safe and in selected patients may limit MTC progression. Lateral cervical node dissection could be beneficial at the time of initial surgical treatment because of the high frequency of residual MTC in the lateral cervical nodes. Noninvasive imaging studies were helpful but far from perfect for guiding the reexploration for locoregional residual MTC.

Differentiated thyroid cancer: "complete" rational approach.

Controversy continues regarding the optimal management of patients with differentiated thyroid cancer because no prospective randomized studies evaluating the merits of (1) extent of thyroidectomy, (2) postoperative radioactive iodine ablation, or (3) thyroid-stimulating hormone (TSH) suppressive therapy exist. Patients with low risk differentiated thyroid cancer enjoy a relatively good prognosis with a mortality rate of about 2% to 5% and a recurrence rate of about 20%. Despite the excellent prognosis in patients considered to be at low risk, total or near-total thyroidectomy in patients with differentiated thyroid cancer has the advantages that: (1) postoperative radioactive iodine can be used to detect and treat residual normal thyroid tissue and local or distant metastases; (2) follow-up serum thyroglobulin levels are a more sensitive marker of persistent or recurrent disease when all thyroid tissue has been removed; and (3) total or near-total thyroidectomy with postoperative (131)I ablation and TSH suppressive therapy is associated with better survival and lower recurrence rates. Patients with occult papillary thyroid cancer and minimally invasive follicular thyroid cancer can be treated by thyroid lobectomy because they have a near-normal life expectancy. Virtually all other patients with differentiated thyroid cancer appear to benefit from more extensive initial treatment.