Fumarate Hydratase Variants and Their Association With Paraganglioma/Pheochromocytoma

OBJECTIVE

To clarify the link between germline variants in fumarate hydratase (FH), hereditary leiomyomatosis and renal cell cancer (HLRCC), and paraganglioma (PGL) and pheochromocytoma (PCC) we utilize a well-annotated hereditary cancer testing database.

METHODS

Records of 120,061 patients receiving germline testing were obtained. FH variants were classified into 4 categories: autosomal dominant (AD) HLRCC variants, autosomal recessive (AR) fumarase deficiency (FMRD), variants, previously reported as PGL/PCC FH variants, and variants of unknown significance (VUS) not previously associated with PGL/PCC (NPP-VUS). Rates of PGL/PCC were compared with those with negative genetic testing.

RESULTS

About 1.3% of individuals carried FH variants which were more common among individuals with PGL/PCC compared to those without (3.1% vs 1.3%, P < .0001). PGL/PCC rates were higher among individuals with PGL/PCC FH variants compared to those with negative genetic testing (22.2% vs 0.9%, P < .0001). Neither AD HLRCC variants (0.3% vs 0.9%, P = .35) nor AR FMRD variants (1.4% vs 0.9%, P = .19) carried an increased prevalence of PGL/PCC. An increased prevalence of PGL/PCC was detected in those with NPP-VUS (2.0% vs 0.9%, P = .0023).

CONCLUSIONS

Certain FH variants confer an increased risk of PGL/PCC, but not necessarily HLRCC. While universal screening for PGL/PCC among all individuals with FH variants does not appear warranted, it should be considered in select high-risk PGL/PCC FH variants.

The effect of α-linolenic acid enrichment in perinatal diets in preventing high fat diet-induced SCD1 increased activity and lipid disarray in adult offspring of low density lipoprotein receptor knockout (LDLRKO) mice

The present study examined the effects of maternal perinatal dietary ALA enrichment on the high fat diet (HFD)-induced lipid disarray in the adult offspring of low density lipoprotein receptor knock-out (LDLRKO) mice. Female LDLRKO mice received, during pregnancy and lactation, isocaloric diets with either corn oil, RD, or flax oil, ALA. The weaning offspring was given a regular chow diet for a washout period of eight weeks, which was followed by HFD for eight weeks. Plasma and liver lipids and SCD1 activity were then analyzed. The HFD-fed RD adult offspring had substantially higher plasma cholesterol levels than the HFD-fed ALA offspring (15.7 versus 9.7 mmole/l, p<0.00001) and non-alcoholic fatty liver disease (NAFLD) (65.0 versus 23.9 mg/g lipids, p<0.00001). Liver lipids oleic acid (OA) content and monounsaturated to saturated fatty acids (MUFA/SAT) ratio, were two times lower in RD compared to ALA (p<0.0001). The threefold HFD-induced SCD1 raised activity (p<0.00001), and OA produced from SA, observed in RD adult offspring were prevented by perinatal ALA. In conclusion, the resilience of SCD1 to HFD- induced increased activity may account for the beneficial effects of perinatal ALA dietary enrichment in preventing NAFLD and hypercholesterolemia from occurring in adult LDLRKO offspring mice.

Thyroid Cancer and Pesticide Use in a Central California Agricultural Area: A Case Control Study

OBJECTIVE

To examine environmental factors that influence risk of thyroid cancer.

METHODS

We performed a case-control study utilizing thyroid cancer cases from the California Cancer Registry (1999-2012) and controls sampled in a population-based manner. Study participants were included if they were diagnosed with thyroid cancer, lived in the study area at their time of diagnosis, and were ≥35 years of age. Controls were recruited from the same area and eligible to participate if they were ≥35 years of age and had been living in California for at least 5 years prior to the interview. We examined residential exposure to 29 agricultural use pesticides, known to cause DNA damage in vitro or are known endocrine disruptors. We employed a validated geographic information system-based system to generate exposure estimates for each participant.

RESULTS

Our sample included 2067 cases and 1003 controls. In single pollutant models and within a 20-year exposure period, 10 out of 29 selected pesticides were associated with thyroid cancer, including several of the most applied pesticides in the United States such as paraquat dichloride [odds ratio (OR): 1.46 (95% CI: 1.23, 1.73)], glyphosate [OR: 1.33 (95% CI: 1.12, 1.58)], and oxyfluorfen [OR: 1.21 (95% CI: 1.02, 1.43)]. Risk of thyroid cancer increased proportionately to the total number of pesticides subjects were exposed to 20 years before diagnosis or interview. In all models, paraquat dichloride was associated with thyroid cancer.

CONCLUSIONS

Our study provides first evidence in support of the hypothesis that residential pesticide exposure from agricultural applications is associated with an increased risk of thyroid cancer.

Three Patients with Lithium-Associated Hyperparathyroidism: Literature Review Regarding Medical and Surgical Management

Lithium (Li) carbonate has been established as a mood stabilizer and an efficacious treatment for bipolar disorder since its discovery by Dr. John Cade in 1948. Li interacts significantly with organ systems and endocrine pathways. One of the most challenging side effects of Li to manage is its effect on the parathyroid glands. Dysregulation of parathyroid signaling due to Li results in hypercalcemia due to increased vitamin D₃ generation, increased calcium absorption from the gut, and bone resorption, occasionally resulting in concomitant hypercalciuria. However, hypercalciuria is not a definitive feature for hyperparathyroidism, and normal calcium excretion might be seen in these patients. Hypercalcemia may also result from volume contraction and decreased renal clearance, which are commonly seen in these patients. Anatomically the parathyroid abnormalities can present as single or multiglandular disease. We report 3 cases where the patients developed multiple side effects of Li therapy as well as hypercalcemia due to hyperparathyroidism. The literature is reviewed with regard to medical and surgical management of Li-associated hyperparathyroidism in the context of these 3 presented cases.

Sustained Growth of a University-Based Endocrine Surgery Program Over 10 Years

BACKGROUND

Endocrine surgery continues to mature as a subspecialty field. We describe the clinical performance of an academic endocrine surgery program (ESP) over its first 10 years.

METHODS

We examined all endocrine procedures performed during the 10-year period (2006-2015) following the inception of the ESP. Institutional and state-level data on case volume, patient geographic origin, and hospital-side costs were obtained.

RESULTS

Endocrine case volume increased by approximately ninefold over the study period (from 102 cases in 2006 to 919 cases in 2015). The rate of growth remained approximately linear, and was driven by geographic expansion of referral regions coupled with transitioning low- to moderate-acuity operations to venues outside of the main tertiary care hospital. Market share across the eight-county Southern California region grew by more than twofold over the study period. Increased utilization of outpatient surgery led to cost reductions, averaging 11.1% per case by 2015.

CONCLUSIONS

Establishment of an academic ESP can lead to sustained clinical growth and a fundamental shift in regional referral patterns. The nation's continued need for skilled high-volume endocrine surgeons represents opportunities for medical centers to institute their own dedicated endocrine surgery programs.

Adipocyte Browning and Higher Mitochondrial Function in Periadrenal But Not SC Fat in Pheochromocytoma

CONTEXT

Patients with pheochromocytoma (pheo) show presence of multilocular adipocytes that express uncoupling protein 1 within periadrenal (pADR) and omental (OME) fat depots. It has been hypothesized that this is due to adrenergic stimulation by catecholamines produced by the pheo tumors.

OBJECTIVE

To characterize the prevalence and respiratory activity of brown-like adipocytes within pADR, OME, and SC fat depots in human adult pheo patients.

DESIGN

This was an observational cohort study.

SETTING

The study took place in a university hospital.

PATIENTS

We studied 46 patients who underwent surgery for benign adrenal tumors (21 pheos and 25 controls with adrenocortical adenomas).

MAIN OUTCOME MEASURE

We characterized adipocyte browning in pADR, SC, and OME fat depots for histological and immunohistological features, mitochondrial respiration rate, and gene expression. We also determined circulating levels of catecholamines and other browning-related hormones.

RESULTS

Eleven of 21 pheo pADR adipose samples, but only one of 25 pADR samples from control patients exhibited multilocular adipocytes. The pADR browning phenotype was associated with higher plasma catecholamines and raised uncoupling protein 1. Mitochondria from multilocular pADR fat of pheo patients exhibited increased rates of coupled and uncoupled respiration. Global gene expression analysis in pADR fat revealed enrichment in β-oxidation genes in pheo patients with multilocular adipocytes. No SC or OME fat depots exhibited aspects of browning.

CONCLUSION

Browning of the pADR depot occurred in half of pheo patients and was associated with increased catecholamines and mitochondrial activity. No browning was detected in other fat depots, suggesting that other factors are required to promote browning in these depots.

Medical Students' Perceptions of Surgeons: Implications for Teaching and Recruitment

OBJECTIVE

The purpose of this study was to assess first-year medical students' implicit perceptions of surgeons, focusing on the roles of gender and demeanor (communal = supportive, associated with women; agentic = assertive, associated with men).

DESIGN

Survey study. Each survey had 1 of 8 possible scenarios; all began with a short description of a surgeon who was described as accomplished and well trained, then varied by surgeon gender (male/female), surgeon demeanor (agentic/communal), and type of surgery (breast cancer/lung cancer). Using a 0 to 5 scale, respondents rated their perception of the surgeon through 5 questions. These 5 items were averaged to create a composite perception score scaled from 0 to 5.

SETTING

Surveys were administered at the University of California, San Francisco, and the University of California, Los Angeles.

PARTICIPANTS

We administered surveys to 333 first-year medical students who could read English and voluntarily agreed to participate.

RESULTS

A total of 238 students responded (71.5%). They preferred the communal vs agentic surgeon (4.2 ± 0.7 vs 3.9 ± 0.7, p = 0.002) and male medical students perceived surgeons more favorably than female medical students did (4.2 ± 0.6 vs 4.0 ± 0.8, p = 0.036). The preference score did not differ according to surgeon gender (female 4.12 vs male 3.98, p = 0.087). There were no significant interactions between the factors of student gender, surgeon gender, or demeanor. Students who reported an interest in surgery as a career did not perceive surgeons more favorably than the students interested in other fields (4.3 ± 0.7 vs 4.0 ± 0.7 respectively, p = 0.066).

CONCLUSIONS

Based on our findings, surgeon educators would likely find success in teaching and recruiting medical students by employing a communal demeanor in their interactions with all students, regardless of the students' gender or stated interest in surgery.

Dynamic Parathyroid Computed Tomography (4DCT) Facilitates Reoperative Parathyroidectomy and Enables Cure of Missed Hyperplasia

BACKGROUND

Four-dimensional computed tomography (4DCT) is an emerging imaging modality in the evaluation of primary hyperparathyroidism (PHPT). We assessed the role of 4DCT in patients presenting for reoperative parathyroidectomy.

METHODS

A prospective database of patients with persistent or recurrent PHPT undergoing reoperative parathyroidectomy during the years 2006-2014 was analyzed. Patients treated before versus after the advent of 4DCT were compared for operative eligibility, operative success, operative time, and concordance of imaging results with surgical findings.

RESULTS

Ninety patients were included in the study (61 before 4DCT, 29 after 4DCT). The post-4DCT group had a higher rate of surgical concordance with imaging results (63 vs. 90 %, p < 0.01) and shorter operative time (114 vs. 76 min, p < 0.05). The operative success rate was not different (87 vs. 86 %). A similar pattern was observed in the subset of sestamibi-negative patients, with post-4DCT patients having a higher rate of surgical concordance (12 vs. 83 %, p < 0.0001) and shorter operative time (181 vs. 89 min, p < 0.05). Among patients ultimately found to have parathyroid hyperplasia, 4DCT correctly identified multiple enlarged glands in 80 % (4 of 5) and correctly lateralized one or more glands in 100 % (5 of 5) of cases, facilitating successful subtotal parathyroidectomy in the reoperative setting.

CONCLUSIONS

4DCT enables successful and efficient reoperative parathyroidectomy. These benefits extend to difficult cases, including sestamibi-negative patients and those with missed hyperplasia.

Predictors of Multigland Disease in Primary Hyperparathyroidism: A Scoring System with 4D-CT Imaging and Biochemical Markers

BACKGROUND AND PURPOSE

Multigland disease represents a challenging group of patients with primary hyperparathyroidism. Additional lesions may be missed on imaging because they are not considered or are too small to be seen. The aim of this is study was to identify 4D-CT imaging and biochemical predictors of multigland disease.

MATERIALS AND METHODS

This was a retrospective study of 155 patients who underwent 4D-CT and successful surgery with a biochemical cure that compared patients with multigland and single-gland disease. Variables studied included the size of the largest lesion on 4D-CT, the number of lesions prospectively identified on 4D-CT, serum calcium levels, serum parathyroid hormone levels, and the Wisconsin Index (the product of serum calcium and parathyroid hormone levels). Imaging findings and the Wisconsin Index were used to calculate a composite multigland disease scoring system. We evaluated the predictive value of individual variables and the scoring system for multigland disease.

RESULTS

Thirty-six patients with multigland disease were compared with 119 patients with single-gland disease. Patients with multigland disease had significantly lower Wisconsin Index scores, smaller lesion size, and a higher likelihood of having either multiple or zero lesions identified on 4D-CT (P ≤ .01). Size cutoff of <7 mm had 85% specificity for multigland disease, but including other variables in the composite multigland disease score improved the specificity. Scores of ≥4, ≥5, and 6 had specificities of 81%, 93%, and 98%, respectively.

CONCLUSIONS

The composite multigland disease scoring system based on 4D-CT imaging findings and biochemical data can identify patients with a high likelihood of multigland disease. Communicating the suspicion for multigland disease in the radiology report could influence surgical decision-making, particularly when considering re-exploration in a previously operated neck or initial limited neck exploration.

Reproductive outcomes and nononcologic complications after radioactive iodine ablation for well-differentiated thyroid cancer

BACKGROUND

Radioactive iodine (RAI) ablation is frequently performed after initial surgery for well-differentiated thyroid cancer (WDTC). We examined the frequency and timing of childbirth as well as nononcologic complications after RAI ablation for WDTC on a population level.

METHODS

A retrospective cohort study of 25,333 patients (18,850 women) with WDTC was performed using the California Cancer Registry and California Office of Statewide Health Planning and Development database, 1999-2008. The primary outcomes were birthrate and median time to first live birth among women of childbearing age. Secondary outcomes were nononcologic diagnoses occurring outside the acute setting (>30 days) after ablation.

RESULTS

RAI ablation did not affect birthrate among women in the full dataset. However, in subgroup analyses, birthrate among women age 35-39 was significantly decreased in those who received RAI versus those who did not (11.5 versus 16.3 births per 1000 woman-years, p<0.001). Median time to first live birth after diagnosis of WDTC was prolonged among women who received RAI compared to those who did not (34.5 versus 26.1 months; p<0.0001). When 5-year age groups were examined individually, delay to first live birth was observed in women age 20-39 (p<0.05). This remained significant after adjustment for tumor characteristics, socioeconomic status, and marital status. The only nononcologic, nonreproductive adverse effect associated with RAI ablation was an increased rate of nasolacrimal stenosis (RR 3.44, p<0.0001).

CONCLUSIONS

RAI ablation is associated with delayed childbearing in women across most of the reproductive lifespan, and with decreased birthrate in the late reproductive years. The underlying mechanism likely involves physician recommendation to delay pregnancy, as well as a potential impact of RAI on both reproductive choice and reproductive health. Further investigation is merited.

Surgery is associated with improved survival for adrenocortical cancer, even in metastatic disease

BACKGROUND

Adrenocortical carcinoma (ACC) is a rare but lethal tumor. Predictors of survival include earlier stage at presentation and complete operative resection. We assessed effect of treatment and demographic variables on survival.

METHODS

ACC cases were abstracted from the California Cancer Registry and Office of Statewide Health Planning and Development (1999-2008). Predictors included patient demographics, comorbidities, tumor size, stage, and treatment (none, surgery, chemotherapy and/or radiation [CRT], and surgery plus CRT).

RESULTS

We studied 367 patients with median tumor size of 10 cm. At presentation, 37% had localized, 17% had regional, and 46% had metastatic disease. Median survival was 1.7 years (7.4 years local, 2.6 years regional, and 0.3 years metastatic, P < .0001). One-year and 5-year survival was: 92%/62% (local); 73%/39% (regional); and 24%/7% (metastatic). Increased age (hazard ratio [HR] 1.16) and Cushing's syndrome (HR 1.66) worsened survival (P < .05). Low socioeconomic status worsened survival in local and regional disease (P < .05). In multivariable regression, both surgery (regional HR 0.13; metastatic HR 0.52) and surgery plus CRT (regional HR 0.15; metastatic HR 0.31) improved survival compared with no treatment (P < .02).

CONCLUSION

In ACC, surgery is associated with improved survival, even in metastatic disease. Surgery should be considered for select patients as part of multimodality treatment.

Thyroglobulin antibody levels do not predict disease status in papillary thyroid cancer

BACKGROUND

Thyroglobulin antibodies (TgAb) are present in approximately 20% of patients with papillary thyroid cancer (PTC) and invalidate the serum thyroglobulin (Tg) level as a tumour marker. We examined whether trends in the TgAb level could serve as a surrogate marker of disease status in the surveillance of patients with PTC.

METHODS

All patients found to have a least one positive postoperative TgAb level (determined by the Beckman-Coulter Access Assay) after undergoing initial surgery for PTC from 2000 to 2010 at a single institution were included. Log-log transformation and linear regression were applied to longitudinal TgAb levels, yielding patient-specific regression coefficients that categorized as follows: highly negative, moderately negative and positive/no trend. The recurrence rate in each category was then assessed.

RESULTS

Ninety-three of 967 patients with PTC were included. Recurrent disease was detected in 19 patients (20%) after a mean follow-up time of 51 months. Regression coefficients in the highly negative and moderately negative groups were not different, and hence these groups were pooled. The proportion of recurrent cases in the negative trend group was similar to that in the positive/no trend group (19.7% vs 21.9%, NS). The mean regression coefficients were similar for recurrent and nonrecurrent cases within both the negative trend group (-0.89 vs -0.80, NS) and the positive/no trend group (0.08 vs 0.33, NS).

CONCLUSION

Trends in the TgAb level do not predict disease status in PTC in our experience. In the context of most commercially available TgAb assays, surveillance of TgAb-positive patients will hinge on high-quality imaging until a valid alternative serum marker to Tg is identified.

Utility of serum thyroglobulin measurements after prophylactic thyroidectomy in patients with hereditary medullary thyroid cancer

INTRODUCTION

Prophylactic thyroidectomy can be curative for patients with hereditary medullary thyroid cancer (MTC) caused by RET proto-oncogene mutations. Calcitonin is a sensitive tumor marker used to follow patients. We suggest that thyroglobulin (Tg) levels should also be monitored postoperatively in these patients.

METHODS

We reviewed patients with RET mutations who underwent prophylactic thyroidectomy between 1981 and 2011 at an academic endocrine surgery center. Patients were excluded if they had no postoperative Tg levels recorded.

RESULTS

Of the 22 patients who underwent prophylactic thyroidectomy, 14 were included in the final analysis. The average age at thyroidectomy was 9.8 years (range, 4-29). Tg levels were detectable 1.5 months to 31 years postoperatively in 11 patients (79%), all of whom were <15 years old at thyroidectomy. Median thyroid-stimulating hormone (TSH) was 2.5 mIU/L and 13.4 mIU/L in patients with undetectable and detectable Tg, respectively. Of those with detectable Tg, 5 had cervical ultrasonographic examination: Two showed no residual tissue in the thyroid bed, and 3 showed remnant thyroid tissue.

CONCLUSION

Tg levels can identify patients with remnant thyroid tissue after prophylactic thyroidectomy. Ultrasonography can determine whether thyroid tissue remains posterolaterally that is at risk of MTC recurrence. Maintaining normal TSH may prevent growth of remaining thyroid follicular cells.

Risk-based ultrasound screening for thyroid cancer in obese patients is cost-effective

BACKGROUND

A higher body mass index (BMI) is associated with more advanced stages of thyroid cancer. Screening obese patients for thyroid cancer has been proposed but has yet to be examined for cost-effectiveness. The objective of this study was to assess the cost-effectiveness of ultrasound (US) screening of obese patients for thyroid cancer.

METHODS

A decision-tree model compared cost savings for the following: (i) base case scenario of an obese patient with thyroid nodule found by palpation, (ii) universal US screening of all obese patients, and (iii) risk-based US screening in obese patients. Risk-based screening consisted of patients who had at least one of four major identified risk factors for thyroid cancer (family history of thyroid cancer, radiation exposure, Hashimoto's thyroiditis, and/or elevated thyrotropin). Patients with nodules underwent established treatment and management guidelines. The model accounted for recurrence, complications, and long-term treatment/follow-up for five years. Outcome probabilities were identified from a literature review. Costs were estimated using a third-party payer perspective. Sensitivity analyses were performed to examine the impact of risk factor prevalence and US cost on the model.

RESULTS

The resulted costs per patient were $210.73 in the base case scenario, $434.10 in the universal US screening arm, and $166.72 in the risk-based screening arm. Risk-based screening remained cost-effective until more than 14% of obese patients had risk factors and with a wide variation of US costs ($0-$1113).

CONCLUSION

Risk-based US screening in selected obese patients with risk factors for thyroid cancer is cost-effective. Recommendations for screening this subgroup will result in cost savings and a likely decreased morbidity and mortality in this subpopulation with more aggressive disease.

Racial and socioeconomic disparities in presentation and outcomes of well-differentiated thyroid cancer

CONTEXT

Racial/ethnic minorities suffer disproportionate morbidity and mortality from chronic diseases.

OBJECTIVE

Our objective was to assess racial and socioeconomic status (SES) disparities in well-differentiated thyroid cancer (WDTC) patients.

DESIGN AND PARTICIPANTS

We conducted a retrospective cohort study on 25 945 patients with WDTC (1999-2008) from the California Cancer Registry (57% white, 4% black, 24% Hispanic, and 15% Asian-Pacific Islander [API]).

MAIN OUTCOMES

We evaluated effect of race and SES variables on stage of cancer presentation and overall/disease-specific survival.

RESULTS

Significant differences in stage of presentation between all racial groups were found (P<.001), with minority groups presenting with a higher percentage of metastatic disease as compared with white patients (black, odds ratio [OR]=1.36 with confidence interval [CI] 1.01-1.84; Hispanic, OR=1.89 [CI, 1.62-2.21], API, OR=1.82 [CI, 1.54-2.15]). Hispanic (OR=1.59, [CI, 1.48-1.72]) and API (OR=1.32 [1.22-1.44]) patients also presented with higher odds of regional disease. Patients with the lowest SES presented with metastatic disease more often than those with the highest SES (OR=1.45 [CI, 1.16-1.82]). Those that were poor/uninsured and/or with Medicaid insurance had higher odds of presenting with metastatic disease as compared with those with private insurance (OR=2.41, [CI, 2.10-2.77]). Unadjusted overall survival rates were higher among API and Hispanic patients and lower among black patients (P<.001 vs white patients). Adjusted overall survival also showed a survival disadvantage for black patients (hazard ratio=1.4, [CI, 1.10-1.73]) and survival advantage for API patients (hazard ratio=0.83, [CI, 0.71-0.97]). In disease-specific survival analyses, when only those patients with metastatic disease were analyzed separately, black patients again had the lowest survival rates, and Hispanic/API patients had the highest survival rates (P<.04).

CONCLUSION

Black patients and those with low SES have worse outcomes for thyroid cancer. API and Hispanic patients may have a protective effect on survival despite presenting with more advanced disease.

Incidence and prevalence of primary hyperparathyroidism in a racially mixed population

CONTEXT

The epidemiology of primary hyperparathyroidism (PHPT) has generally been studied in Caucasian populations.

OBJECTIVE

The aim was to examine the incidence and prevalence of PHPT within a racially mixed population.

DESIGN

A descriptive epidemiologic study was performed.

PATIENTS/SETTING

The study population included 3.5 million enrollees within Kaiser Permanente Southern California.

METHODS

All patients with at least one elevated serum calcium level (>10.5 mg/dL, 2.6 mmol/L) between 1995 and 2010 were included. Cases of PHPT were identified by electronic query of laboratory values using biochemical criteria, after exclusion of secondary or renal and tertiary hyperparathyroidism cases. The incidence and prevalence rates of PHPT were calculated according to sex, race, age group by decade, and year.

RESULTS

Initial case finding identified 15,234 patients with chronic hypercalcemia, 13,327 (87%) of which had PHPT as defined by elevated or inappropriately normal parathyroid hormone levels. The incidence of PHPT fluctuated from 34 to 120 per 100,000 person-years (mean 66) among women, and from 13 to 36 (mean 25) among men. With advancing age, incidence increased and sex differences became pronounced (incidence 12-24 per 100,000 for both sexes younger than 50 y; 80 and 36 per 100,000 for women and men aged 50-59 y, respectively; and 196 and 95 for women and men aged 70-79 y, respectively). The incidence of PHPT was highest among blacks (92 women; 46 men, P < .0001), followed by whites (81 women; 29 men), with rates for Asians (52 women, 28 men), Hispanics (49 women, 17 men), and other races (25 women, 6 men) being lower than that for whites (P < .0001). The prevalence of PHPT tripled during the study period, increasing from 76 to 233 per 100,000 women and from 30 to 85 per 100 000 men. Racial differences in prevalence mirrored those found in incidence.

CONCLUSIONS

PHPT is the predominant cause of hypercalcemia and is increasingly prevalent. Substantial differences are found in the incidence and prevalence of PHPT between races.

Endocrine surgery as a model for value-based health care delivery

Background:

Experts advocate restructuring health care in the United States into a value-based system that maximizes positive health outcomes achieved per dollar spent. We describe how a value-based system implemented by the University of California, Los Angeles UCLA Section of Endocrine Surgery (SES) has optimized both quality and costs while increasing patient volume.

Methods:

Two SES clinical pathways were studied, one allocating patients to the most appropriate surgical care setting based on clinical complexity, and another standardizing initial management of papillary thyroid carcinoma (PTC). The mean cost per endocrine case performed from 2005 to 2010 was determined at each of three care settings: A tertiary care inpatient facility, a community inpatient facility, and an ambulatory facility. Blood tumor marker levels (thyroglobulin, Tg) and reoperation rates were compared between PTC patients who underwent routine central neck dissection (CND) and those who did not. Surgical patient volume and regional market share were analyzed over time.

Results:

The cost of care was substantially lower in both the community inpatient facility (14% cost savings) and the ambulatory facility (58% cost savings) in comparison with the tertiary care inpatient facility. Patients who underwent CND had lower Tg levels (6.6 vs 15.0 ng/mL; P = 0.024) and a reduced need for re-operation (1.5 vs 6.1%; P = 0.004) compared with those who did not undergo CND. UCLA maintained its position as the market leader in endocrine procedures while expanding its market share by 151% from 4.9% in 2003 to 7.4% in 2010.

Conclusions:

A value-driven health care delivery system can deliver improved clinical outcomes while reducing costs within a subspecialty surgical service. Broader application of these principles may contribute to resolving current dilemmas in the provision of care nationally.

Parathyroid carcinoma: update and guidelines for management

Parathyroid carcinoma is one of the rarest known malignancies that may occur sporadically or as a part of a genetic syndrome. It accounts for approximately 1% of patients with primary hyperparathyroidism. The majority (90%) of parathyroid cancer tumors are hormonally functional and hypersecrete parathyroid hormone (PTH). Thus, most patients exhibit strong symptomatology of hypercalcemia at presentation. Sometimes, it can be difficult to diagnose parathyroid cancer preoperatively due to clinical features shared with benign causes of hyperparathyroidism. Imaging techniques such as neck ultrasound and 99mTc sestamibi scan can help localize disease, but they are not useful in the assessment of malignancy potential. Fine needle aspiration (FNA) prior to initial operation is not recommended due to technical difficulty in differentiating benign and malignant disease on cytology specimens and the possible associated risk of tumor seeding from the needle track. Complete surgical resection with microscopically negative margins is the recommended treatment and offers the best chance of cure. Persistent or recurrent disease occurs in more than 50% of patients with parathyroid carcinoma. Surgical resection is also the primary mode of therapy for recurrence since it can offer significant palliation for the metabolic derangement caused by hyperparathyroidism and allows hypercalcemia to become more medically manageable. However, reoperation is rarely curative and eventual relapse is likely. Chemotherapy and external beam radiation treatments have been generally ineffective in the treatment of parathyroid carcinoma. Typically, these patients require repeated operations that predispose them to accumulated surgical risks with each intervention. In inoperable cases, few palliative treatment options exist, although treatment with calcimimetics can effectively control hypercalcemia in some patients. Most patients ultimately succumb to complications of hypercalcemia rather than from tumor burden or infiltration.

Parathyroid carcinoma: a 43-year outcome and survival analysis

CONTEXT

Parathyroid carcinoma is a rare but ominous cause of primary hyperparathyroidism. OBJECTIVES AND MAIN OUTCOME MEASURES: The objective of the study was to review the outcomes of parathyroid cancer patients and to evaluate the factors associated with mortality.

DESIGN, SETTING, AND PATIENTS

This was a retrospective review performed on 37 patients with parathyroid cancer treated at a single university tertiary care center between 1966 and 2009.

RESULTS

The average age at cancer diagnosis was 53 yr (range 23-75 yr), and 23 patients (62%) were men. Eighteen patients (49%) recurred after their initial cancer operation. The average number of neck dissections done for cancer was three (range 1-11). After initial diagnosis, 22 patients (60%) eventually developed complications, including unilateral (n = 11) or bilateral (n = 3) vocal cord paralysis (38%). Eight patients (22%) had, at some point, an associated benign parathyroid adenoma. Median overall survival was 14.3 yr (range 10.5-25.7 yr) from the date of diagnosis. Factors associated with increased mortality included lymph node or distant metastases, number of recurrences, higher calcium level at recurrence, and a high number of calcium-lowering medications. Factors not associated with mortality included age, race, tumor size, time to first recurrence, and extent of initial operation. Initial operations done at our center had improved survival (P = 0.037) and decreased complication rates (P < 0.001) vs. those done elsewhere.

CONCLUSION

Parathyroid cancer patients typically have a long survival, which often includes multiple reoperations for recurrence and thus a high rate of surgical complications. Patients in whom there is a high index of suspicion for parathyroid cancer should be referred to a dedicated endocrine surgery center for their initial operation.

Classification and nomenclature system for human Alphapapillomavirus variants: general features, nucleotide landmarks and assignment of HPV6 and HPV11 isolates to variant lineages

BACKGROUND

Papillomaviruses constitute a family of viruses that can be classified into genera, species and types based on their viral genome heterogeneity. Currently circulating infectious human Alphapapillomaviruses (alpha-PVs) constitute a set of viral genomes that have evolved from archaic times and display features of host co-speciation. Viral variants are more recently evolved genomes that require a standardized classification and nomenclature.

OBJECTIVES

To describe a system for the classification and nomenclature of HPV viral variants and provide landmarks for the numbering of nucleotide positions.

METHODS

The complete 8 kb genomes of the alpha-9 species group and HPV6 and 11 types, collected from isolates throughout the world were obtained from published reports and GenBank. Complete genomes for each HPV type were aligned using the E1 start codon and sequence divergence was calculated by global and pairwise alignments using the MUSCLE program. Phylogenetic trees were constructed from the aligned sequences using a maximum likelihood method (RAxML).

RESULTS

Pairwise comparisons of nucleotide differences between complete genomes of each type from alpha-9 HPV isolates (HPV16, 31, 33, 35, 52, 58 and 67) revealed a trimodal distribution. Maximum heterogeneity for variants within a type varied from 0.6%-2.3%. Nucleotide differences of approximately 1.0%-10.0% and 0.5%-1.0% of the complete genomes were used to define variant lineages and sublineages, respectively. Analysis of 43 HPV6 complete genomes indicated the presence of 2 variant lineages, whereas 32 HPV11 isolates were highly similar and clustered into 2 sublineages. A table was constructed of the human alpha-PV landmark nucleotide sequences for future reference and alignments.

CONCLUSIONS

A proposed nomenclature system for viral variants and coordination of nucleotide positions will facilitate the comparison of variants across geographic regions and amongst different populations. In addition, this system will facilitate study of pathogenic, tissue tropism and functional differences amongst variant lineages of and polymorphisms within HPV variants.

Primary hyperparathyroidism patients with positive preoperative sestamibi scan and negative ultrasound are more likely to have posteriorly located upper gland adenomas (PLUGs)

Background

Standard preoperative imaging for primary hyperparathyroidism usually includes sestamibi scanning (MIBI) and ultrasound (US). In a subset of patients with a positive MIBI and a negative US, we hypothesize that the parathyroid adenomas are more likely to be located posteriorly in the neck, where anatomically they are more difficult to detect by US.

Methods

We retrospectively reviewed the records of 661 patients treated for primary hyperparathyroidism between 2004 and 2009 at a tertiary referral center. We included patients who for their first operation had a MIBI that localized a single lesion in the neck and an US that found no parathyroid adenoma. We excluded patients with persistent or recurrent hyperparathyroidism, and patients with MIBIs that were negative, that had more than one positive focus, or that had foci outside of the neck. Sixty-six cases were included in the final analysis.

Results

A total of 54 patients (83%) had a single adenoma, 4 (6%) had double adenomas, and 7 (11%) had hyperplasia. Thirty-three patients (51%) had a single upper gland adenoma; 19 of these (58%) were posteriorly located upper gland adenomas (PLUGs). PLUGs occurred more often on the right side than on the left (P = 0.048, Fisher’s test). PLUGs were also larger than other single adenomas (mean 1.85 vs. 1.48 cm, P = 0.021, t-test). Seventy-six percent of patients successfully underwent a unilateral or focused exploration. Six patients (9%) had persistent disease, which is double our group’s overall average (4–5%).

Conclusions

Primary hyperparathyroid patients with preoperative positive MIBI and negative US are more likely to have PLUGs.

Malignant pheochromocytoma: a review

BACKGROUND

Pheochromocytomas are rare catecholamine-secreting tumors. Approximately 10 percent of pheochromocytomas are malignant. Traditionally, there has been no reliable method available to predict the malignant potential of pheochromocytoma. However, recent research has increased focus on differentiating at the time of surgery/diagnosis those pheochromocytoma tumors which have malignant potential. In this review, we discuss the current information known of malignant pheochromocytomas.

DATA SOURCES

The PubMed database was searched for articles on malignant pheochromocytoma published between 1993 and 2010.

CONCLUSIONS

The difficult task of predicting the malignant potential of a pheochromocytoma has yet to be answered definitively. However, all the studies presented give an idea of what we may look for in these tumors at the time of diagnosis. We have provided an algorithm based on the most current information known. A much larger study should be performed to test many of these theories with enough power to determine a standard of care.

Adrenal incidentaloma: does an adequate workup rule out surprises?

BACKGROUND

Adrenal incidentaloma remains a diagnostic challenge. Despite well-established management guidelines, the long-term results of following these guidelines are unknown. We sought to determine how accurately these guidelines identify functioning incidentalomas and how often these guidelines result in adrenalectomy for benign tumors.

METHODS

We catalogued adrenal incidentalomas from a retrospective review of 500 consecutive adrenalectomies at a single institution. The outcome measures studied were patient demographics, preoperative biochemical analysis, imaging characteristics, tumor size, type of operation performed, and postoperative histologic diagnosis.

RESULTS

Eighty-one of the 500 adrenalectomies performed were for incidentalomas. Size was the only significant characteristic that distinguished cortical cancers from benign adenomas. Only 1 out of 26 functioning tumors was incorrectly identified on preoperative workup. We also found that 25% of cortisol-secreting incidentalomas were cystic, and that benign adenomas accounted for 42% of all tumors resected.

CONCLUSION

Current guidelines accurately predict the functional status of adrenal incidentalomas. Some cystic lesions may be functioning and should therefore be screened for hormonal hypersecretion. However, even with the most up-to-date diagnostic tools available, most adrenal incidentalomas resected are benign tumors.

Negative preoperative localization leads to greater resource use in the era of minimally invasive parathyroidectomy

BACKGROUND

Successful preoperative localization plays an important role in patient selection for focused parathyroidectomy.

METHODS

The case records of 499 consecutive patients with presumed hyperparathyroidism who underwent neck exploration were reviewed. Positive imaging patients (n = 373) had a localizing study that clearly showed a single abnormal parathyroid gland whereas negative imaging patients (n = 44) failed to localize or had discordant imaging results.

RESULTS

Positive imaging patients were more likely to have a single adenoma (93.0% vs 72.1%; P < .001), and were less likely to require a bilateral exploration (8.1% vs 70.4%; P < .001). Negative imaging patients required more frozen sections (.9 +/- 1.3 vs .2 +/- .7; P < .001), and longer surgical time (77.3 +/- 52.5 min vs 48.4 +/- 34.6 min; P < .001). The cure rate was significantly higher in the positive imaging group (96.0% vs 87.1%; P < .03), with no difference in the incidence of complications (3.2% vs 2.3%; P value was not significant).

CONCLUSIONS

Patients with unsuccessful or discordant preoperative localization have a higher incidence of multigland disease, lower cure rate, and consume more institutional resources than patients with successful preoperative localization.

[Specific interferon-gamma assays: a modern tool for tuberculosis diagnosis]

Compared with the tuberculin skin test, the antigen-specific interferon-gamma assays, using a combination of two antigens ESAT-6 and CFP-10, has higher specificity for the diagnosis of latent tuberculosis, better correlation with exposure to M. tuberculosis, no cross-reactivity due to BCG vaccination and less towards nontuberculous mycobacterial infection. Fewer false positive results in uninfected persons avoid the costs of unnecessary therapy and its possible side effects. In low endemic areas, interferon-y assays are useful in addition of diagnostic algorithm for individuals with suspected tuberculosis. Further studies are required to evaluate the utility of the interferon-gamma assays in specialised subgroups of patients (immunocompromised, young children, patients with extrapulmonary disease,...) and as a marker of disease activity.

Respiratory effects of intrathecal morphine after upper abdominal surgery

The effects of intrathecal (IT) administration of two doses of morphine (Group 1: 2 mg, n = 9; Group 2: 5 mg, n = 10) were studied in 19 patients after upper abdominal surgery. The ventilatory variables and occlusion pressure (P0.1) were recorded during room air breathing and during CO2 rebreathing tests prior to surgery, 24 h after surgery before IT morphine (n = 12), and 3, 5, 7, 11, and 24 h after injection. During room air breathing, minute ventilation (VE) did not change significantly in Group 1 and decreased significantly 3, 5, 7, and 11 h after injection in Group 2. During the rebreathing tests, there was a significant shift to the right of the ventilatory response to CO2 in both groups. The peak of the ventilatory depression was delayed, occurring 7 h and 11 h postinjection in Groups 1 and 2, respectively. Two patients in Group 2 developed clinically significant ventilatory depression. The shallow breathing observed after surgery was not changed after analgesia. In group 2, 5, mg IT morphine was responsible for a significant decrease in f60 (respiratory frequency for a PETCO2 of 60 mmHg). P0.1 increased markedly after surgery during both room air breathing and the rebreathing tests. After IT morphine, compared with the postoperative preanalgesic values, P0.1(60) (P0.1 at a PETCO2 of 60 mmHg) did not change in Group 1 and decreased significantly in Group 2. It is concluded that IT morphine is responsible for a ventilatory depression that is delayed and seems to be dose related and that analgesia does not abolish the shallow breathing observed after upper abdominal surgery.