Clinical characteristics and outcomes of adrenal hemorrhage

BACKGROUND

Although uncommon, adrenal hemorrhage has multiple etiologies. Because clinical characteristics, management, and outcomes of patients with adrenal hemorrhage are inadequately described, we examined the underlying etiology, need for intervention, evolution of imaging characteristics, and adequacy of subsequent evaluation.

METHODS

We performed a retrospective review of patients diagnosed with adrenal hemorrhage (radiologist-confirmed density consistent with hemorrhage on computed tomography) from 2005 to 2021 at a university-based institution. Demographic characteristics, hemorrhage etiology, and subsequent follow-up were analyzed.

RESULTS

Of 193 adrenal hemorrhage patients, the mean age was 49.2 ± 18.3 years, and 35% were female. Clinical presentations included trauma (47%), abdominal or flank pain (28%), incidental findings on imaging acquired for other reasons (12%), postoperative complication (8%), or shock (3%). Hemorrhage outside of the gland was present in 62% of patients. Unilateral hemorrhage was more frequent (93%) than bilateral (7%). A total of 12% of patients had nodules, but only 70% of these were identified on initial imaging, and only 43% had hormonal evaluation. Of 7 patients who had adrenalectomy or biopsy, pathology was either benign (57%) or nonadrenal malignancy (43%). No adrenocortical carcinomas were identified. Follow-up imaging was performed in 56% of patients and revealed decreased, stable, resolved, or increased adrenal hemorrhage size in 39%, 19%, 30%, and 12% of patients, respectively.

CONCLUSION

Adrenal hemorrhage is secondary to multiple etiologies, most commonly trauma. In the setting of adrenal hemorrhage, many adrenal nodules were not identified on initial imaging. Only a minority of patients with nodules underwent "complete" biochemical evaluation. Follow-up imaging may improve the identification of underlying nodules needing hormonal evaluation.

Heterogeneous parathyroid near-infrared autofluorescence patterns are associated with single adenomas in primary hyperparathyroidism

BACKGROUND

Primary adenoma (PA) and multi-gland hyperplasia (MGH) account for 85% and 15% of primary hyperparathyroidism (PHPT) cases, respectively. Near-infrared autofluorescence (NIRAF) enhances intraoperative parathyroid identification. We hypothesized that PA would display a more heterogeneous NIRAF pattern compared to MGH.

METHODS

Patients undergoing surgery for sporadic PHPT were categorized based on the presence of PA or MGH. To quantify heterogeneity, we utilized ratios of (1) mean parathyroid gland (PG) NIRAF over background NIRAF (mean ratio), (2) minimum and (3) maximum PG NIRAF over mean PG NIRAF (minimum and maximum ratios). Additionally, a heterogeneity score was quantified using mean ratio (mean PG NIRAF over background NIRAF), and overall NIRAF (mean NIRAF of eight random 15 × 15 pixel areas). A point was assigned to ratios <0.8 or >1.2. Images were quantified by ImageJ software. Mann-Whitney test was performed for all comparisons.

RESULTS

Of 78 patients, 63 had a single PA and 15 had MGH, totaling 102 PGs. There was no difference between their mean ratios. PA had a lower minimum ratio compared to that of MGH (0.86 ± 0.01 vs. 0.93 ± 0.01, p = 0.001) and a brighter maximum ratio (1.21 ± 0.02 vs. 1.12 ± 0.01, p = 0.0008). PA also scored higher on their heterogeneity scores compared to MGH (1.27 ± 0.23 vs. 0.33 ± 0.15, p = 0.001).

CONCLUSION

Single parathyroid adenomas display a more heterogeneous autofluorescence pattern compared to that of multi-gland hyperplasia. Intraoperative characterization of PGs by real-time NIR imaging patterns may be a beneficial adjunct during parathyroid surgery.

Efficacy and safety of near-infrared fluorescence identification of the thoracic duct during left lateral neck dissection

BACKGROUND

Thoracic duct leaks occur in up to 5% of left lateral neck dissections. No one imaging modality is routinely used to identify the thoracic duct intraoperatively. The goal of our study was to evaluate the efficacy and safety of indocyanine green lymphangiography for intraoperative identification of the thoracic duct compared to traditional methods using ambient and evaluate the optimal timing of indocyanine green administration.

METHODS

We enrolled all patients who underwent left lateral neck dissection at our institution from 2018 to 2022 in this prospective clinical trial. After indocyanine green injection into the dorsum of the foot, we performed intraoperative imaging was performed with a near-infrared fluorescence camera. We reported the data using descriptive statistics.

RESULTS

Of the 42 patients we enrolled, 14 had prior neck surgery, and 3 had prior external beam radiation. We visualized the thoracic duct with ambient light in 48% of patients and with near-infrared fluorescence visualization in 64%. In 17% of patients, we could identify the thoracic duct only using near-infrared fluorescence visualization, which occurred within 3 minutes of injection, and were required to re-dose 5 patients. We visualized the thoracic duct with near-infrared fluorescence in all patients with prior neck radiation and 77% of patients with prior neck surgery. One adverse reaction occurred (hypotension), and 5 intraoperative thoracic duct injuries occurred that were ligated. There with no chylous fistulas postoperatively.

CONCLUSION

This trial demonstrates that near-infrared fluorescence identification of the thoracic duct is feasible and safe with indocyanine green lymphangiography, even in patients with prior neck surgery or radiation.

Neoadjuvant dabrafenib and trametinib for functional organ preservation in recurrent BRAF V600E-mutated papillary thyroid cancer

OBJECTIVES

To describe the first reported use of neoadjuvant dabrafenib and trametinib specifically to permit organ conservation surgery in locally advanced recurrent differentiated thyroid carcinoma.

PATIENTS AND METHODS

A patient presented with locally recurrent, radioiodide-resistant DTC with a BRAF V600E mutation invading the laryngotrachea. Definitive treatment would require a total laryngectomy. She was offered neoadjuvant dabrafenib and trametinib prior to surgery.

RESULTS

A significant radiographic response permitted partial laryngectomy, enabling preservation of voice, early resumption of oral feeding, and avoidance of permanent tracheostomy. At 9 months, she remained free of disease.

CONCLUSION

Neoadjuvant tyrosine kinase inhibitor treatment prior to definitive surgery for locally-invasive recurrent DTC is a potential approach that may limit the degree of surgery and associated morbidity.

Converting a probe-based fluorescence system into an easy-to-use adjunct for the detection of parathyroid glands accidentally resected intraoperatively

PURPOSE

The reported threshold of a near-infrared fluorescence detection probe (FDP) for judging parathyroid glands (PGs) is based on the autofluorescence intensity relative to other non-PG tissues, making it unreliable when not enough reference tissues are measured. We aim to convert FDP into a more convenient tool for identifying accidentally resected PGs by quantitative measurements of autofluorescence in resected tissues.

METHODS

It was a prospective study approved by the Institutional Review Board. The research was divided into two stages: (1) In order to calibrate the novel FDP system, autofluorescence intensity of different in / ex vivo tissues was measured and the optimal threshold was obtained using receiver operating characteristic (ROC) curve. (2) To further validate the effectiveness of the new system, detection rates of incidental resected PGs by pathology in the control group and by FDP in the experimental group were compared.

RESULTS

Autofluorescence of PGs was significantly higher than that of non-PG tissue (43 patients, Mann-Whitney U test, p < 0.0001). An optimal threshold of sensitivity / specificity (78.8% and 85.1%) for discriminating PGs was obtained. The detection rates of experimental group (20 patients) and control group (33 patients) are 5.0% and 6.1% respectively (one-tailed Fisher's exact test, p = 0.6837), indicating the novel FDP system can achieve a similar proportion of PG detection compared with pathological examinations.

CONCLUSIONS

The novel FDP system can be used as an easy-to-use adjunct for detecting PG accidentally resected intraoperatively before the tissues are sent for frozen sections during thyroidectomy surgeries.

TRIAL REGISTRATION

Registration number: ChiCTR2200057957.

Adrenal Near-Infrared Autofluorescence

Context

Parathyroid tissue is one of the few tissues to have strong near-infrared (NIR) autofluorescence, which has been exploited to improve intraoperative parathyroid identification. The US Food and Drug Administration has approved 2 devices for this purpose. Adrenal glands can be difficult to distinguish from surrounding fat, an issue during total adrenalectomy.

Objective

We hypothesized adrenal tissue may also possess considerable NIR autofluorescence.

Methods

Resected patient adrenal specimens were examined after robotic adrenalectomy with an NIR camera intraoperatively. Patients did not receive fluorescent dye. Images were taken of both gross and sectioned specimens. Post hoc image analysis was performed with ImageJ software. Confocal microscopy was performed on selected tissues using immunofluorescence and hematoxylin-eosin staining.

Results

Resected tissue was examined from 22 patients undergoing surgery for pheochromocytomas (6), primary aldosteronism (3), adrenocorticotropin-independent hypercortisolism (10), and a growing or suspicious mass (3). Normal adrenal tissue demonstrated strong NIR autofluorescence. The intensity ratio compared to background (set as 1) for gross images was 2.03 ± 0.51 (P < .0001) compared to adjacent adipose of 1.24 ± 0.18. Autofluorescence from adrenal tumors was also detected at variable levels of intensity. Cortisol-producing tumors had the highest fluorescence ratio of 3.01 ± 0.41. Confocal imaging localized autofluorescence to the cytosol, with the highest intensity in the zona reticularis followed by the zona fasciculata.

Conclusion

Normal and abnormal adrenal tissues possess natural NIR autofluorescence. Highest autofluorescence levels were associated with cortisol-producing tumors. Confocal imaging demonstrated the highest intensity in the zona reticularis. NIR cameras may have the potential to improve identification of adrenal tissue during surgery.

Risk of malignancy in cytologically indeterminate thyroid nodules harboring thyroid stimulating hormone receptor mutations

OBJECTIVES

To evaluate the frequency and risk of malignancy of TSHRpI568T mutations discovered in indeterminate thyroid nodules (ITN) within the Veracyte CLIA laboratory undergoing Afirma^® Genomic Sequencing Classifier (GSC) testing, and to evaluate a broader cohort of TSHR variants and their categorization as Afirma GSC benign (GSC-B) or suspicious (GSC-S). Finally, we seek to assess the risk of malignancy (ROM) of this group of TSHR mutated ITN in the GSC-S category.

METHODS

ITN submitted to Veracyte for Afirma GSC testing between October 2017 and February 2022 were analyzed for TSHR variants and rates of GSC-B and GSC-S were calculated based upon BIII or IV cytology, by TSHR variant codon amino acid (AA) substitution, age, and gender. For GSC-S samples, surgical pathology reports were requested, and the rate of malignancy was calculated.

RESULTS

Five percent of the ITN samples harbored an isolated TSHR variant and 5% of those were classified as GSC-S. Among TSHRpI568T samples, 96% were GSC-B and of the GSC-S samples, 21% were malignant. Among an unselected group of TSHR, absent TSHRpI568T mutations, 16.3% of GSC-S samples were malignant, all but one with codon mutations in the transmembrane subdomains of the TSHR. This prompted a dedicated evaluation of transmembrane codons which revealed a malignancy rate of 10.7% among GSC-S nodules. In total, 13/85 (15.3%) TSHR mutated ITN with Afirma GSC-S results were found to be malignant.

CONCLUSIONS

TSHR variants are rare in ITN, and most are categorized as benign under Afirma GSC testing which carries a < 4% risk of malignancy. For GSC-S ITN with TSHR mutations, the risk of malignancy is ≥= 15%, which is clinically meaningful and may alter treatment or monitoring recommendations for patients.

Cumulative GRAS Score as a Predictor of Survival After Resection for Adrenocortical Carcinoma: Analysis From the U.S. Adrenocortical Carcinoma Database

BACKGROUND

Adrenocortical carcinoma (ACC) is a rare but aggressive malignancy, and many prognostic factors that influence survival remain undefined. Individually, the GRAS (Grade, Resection status, Age, and Symptoms of hormone hypersecretion) parameters have demonstrated their prognostic value in ACC. This study aimed to assess the value of a cumulative GRAS score as a prognostic indicator after ACC resection.

METHODS

A retrospective cohort study of adult patients who underwent surgical resection for ACC between 1993 and 2014 was performed using the United States Adrenocortical Carcinoma Group (US-ACCG) database. A sum GRAS score was calculated for each patient by adding one point each when the criteria were met for tumor grade (Weiss criteria ≥ 3 or Ki67 ≥ 20%), resection status (micro- or macroscopically positive margin), age (≥ 50 years), and preoperative symptoms of hormone hypersecretion (present). Overall survival (OS) and disease-free survival (DFS) by cumulative GRAS score were analyzed by the Kaplan-Meier method and log-rank test.

RESULTS

Of the 265 patients in the US-ACCG database, 243 (92%) had sufficient data available to calculate a cumulative GRAS score and were included in this analysis. The 265 patients comprised 23 patients (10%) with a GRAS of 0, 52 patients (21%) with a GRAS of 1, 92 patients (38%) with a GRAS of 2, 63 patients (26%) with a GRAS of 3, and 13 patients (5%) with a GRAS of 4. An increasing GRAS score was associated with shortened OS (p < 0.01) and DFS (p < 0.01) after index resection.

CONCLUSION

In this retrospective analysis, the cumulative GRAS score effectively stratified OS and DFS after index resection for ACC. Further prospective analysis is required to validate the cumulative GRAS score as a prognostic indicator for clinical use.

Prevalence of cancer and the benign call rate of afirma gene classifier in 18 F-Fluorodeoxyglucose positron emission tomography positive cytologically indeterminate thyroid nodules

BACKGROUND

18 F-Fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) positive (PET+) cytologically indeterminate thyroid nodules (ITNs) have variable cancer risk in the literature. The benign call rate (BCR) of Afirma Gene Classifier (Gene Expression Classifier, GEC, or Genome Sequence Classifier, GSC) in (PET +) ITNs is unknown.

METHODS

This is a retrospective study at our institution of all patients with (PET+) ITNs (Bethesda III/IV) from 1 January 2010 to 21 May 2019 who underwent Afirma testing and/or surgery or repeat FNA with benign cytology.

RESULTS

Forty-five (PET+) ITNs were identified: 31 Afirma-tested (GEC = 20, GSC = 11) and 14 either underwent surgery (n = 13) or repeat FNA (Benign cytology) (n = 1) without Afirma. The prevalence of cancer and noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) including only resected nodules and ITN with repeat benign FNA (n = 33) was 36.4% (12/33). Excluding all Afirma "suspicious" non-resected ITNs and assuming all Afirma "benign" ITNs were truly benign, that prevalence was 28.6% (12/42). The BCR with GSC was 64% compared to 25% with GEC (p = 0.056). Combining GSC/GEC-tested ITNs, the BCR was higher in ITNs demonstrating low/very low-risk sonographic pattern by the American Thyroid Association (ATA) classification and ITNs scoring <4 by the American College of Radiology Thyroid Imaging, Reporting and Data System (ACR-TI-RADS) than ITNs with higher sonographic pattern/score (p = 0.025).

CONCLUSIONS

The prevalence of cancer/NIFTP in (PET+) ITNs was 28.6-36.4% depending on the method of calculation. The BCR of Afirma GSC was 64%. Combining Afirma GEC/GSC-tested ITNs, BCR was higher in ITNs with a lower risk sonographic pattern.

Features of Cytologically Indeterminate Molecularly Benign Nodules Treated With Surgery

BACKGROUND

Most cytologically indeterminate thyroid nodules (ITNs) with benign molecular testing are not surgically removed. The data on clinical outcomes of these nodules are limited.

METHODS

We retrospectively analyzed all ITNs where molecular testing was performed either with the Afirma gene expression classifier or Afirma gene sequencing classifier between 2011 and 2018 at a single institution.

RESULTS

Thirty-eight out of 289 molecularly benign ITNs were ultimately resected. The most common reason for surgery was compressive symptoms (39%). In multivariable modeling, patients aged <40 years, nodules ≥3 cm, presence of an Afirma suspicious nodule other than the index nodule, and compressive symptoms were associated with higher surgery rates with hazard ratios for surgery of 3.5 (P < 0.001), 3.2 (P < 0.001), 16.8 (P < 0.001), and 7.31 (P < 0.001), respectively. Of resected nodules, 5 were malignant. False-negative rate (FNR) was 1.7%, presuming all unresected nodules were truly benign and 13.2% restricting analysis to resected cases. The FNR was significantly higher in nodules with a high-risk sonographic appearance for cancer (American Thyroid Association high-risk classification and American College of Radiology Thyroid Imaging Reporting and Data Systems score of 5) compared with nodules with all other sonographic categories (11.8% vs 1.1%; P = 0.03 and 11.1% vs 1.1%; P = 0.02, respectively).

CONCLUSIONS

Younger age, larger nodule size, presence of an Afirma suspicious nodule other than the index nodule, and compressive symptoms were associated with a higher rate of surgery. The FNR of benign Afirma was significantly higher in nodules with high-risk sonographic features.

Update on Pheochromocytoma and Paraganglioma from the SSO Endocrine/Head and Neck Disease-Site Work Group. Part 1 of 2: Advances in Pathogenesis and Diagnosis of Pheochromocytoma and Paraganglioma

This first part of a two-part review of pheochromocytoma and paragangliomas (PPGLs) addresses clinical presentation, diagnosis, management, treatment, and outcomes. In this first part, the epidemiology, prevalence, genetic etiology, clinical presentation, and biochemical and radiologic workup are discussed. In particular, recent advances in the genetics underlying PPGLs and the recommendation for genetic testing of all patients with PPGL are emphasized. Finally, the newer imaging methods for evaluating of PPGLs are discussed and highlighted.

Update on Pheochromocytoma and Paraganglioma from the SSO Endocrine and Head and Neck Disease Site Working Group, Part 2 of 2: Perioperative Management and Outcomes of Pheochromocytoma and Paraganglioma

This is the second part of a two-part review on pheochromocytoma and paragangliomas (PPGLs). In this part, perioperative management, including preoperative preparation, intraoperative, and postoperative interventions are reviewed. Current data on outcomes following resection are presented, including outcomes after cortical-sparing adrenalectomy for bilateral adrenal disease. In addition, pathological features of malignancy, surveillance considerations, and the management of advanced disease are also discussed.

Intraoperative Autofluorescence Parathyroid Identification in Patients With Multiple Endocrine Neoplasia Type 1

Importance

Intrinsic near-infrared (NIR) autofluorescence of the parathyroid gland enables intraoperative gland identification without the need for contrast agent injection. However, whether real-time autofluorescence imaging is useful in patients with multiple endocrine neoplasia type 1 (MEN1) and primary hyperparathyroidism is unknown.

Objective

To compare quantified intraoperative parathyroid autofluorescence imaging results for patients with MEN1-associated vs those with non-MEN1 sporadic primary hyperparathyroidism.

Design, Setting, and Participants

A retrospective analysis of prospectively collected data on a cohort of 71 consecutive patients undergoing surgery for primary hyperparathyroidism by 2 experienced endocrine surgeons between June 1, 2017, and July 31, 2018, was conducted. Intraoperative imaging was performed with a handheld NIR autofluorescence device and images were captured for analysis. Post hoc blinded imaging analysis was conducted with Image J software to quantify representative areas of greatest autofluorescence from the parathyroid, thyroid, and adjacent soft tissue.

Main Outcomes and Measures

Primary end points were parathyroid autofluorescence and background thyroid and soft tissue autofluorescence, reported as median values with interquartile ranges. Rates of false-negative (lack of significant parathyroid gland autofluorescence compared with background autofluorescence, defined as parathyroid autofluorescence-background autofluorescence ratio <1.10) and false-positive autofluorescence (aberrant autofluorescence of nonparathyroid tissue confirmed by pathologic testing) were analyzed.

Results

Of the 71 consecutive patients with primary hyperparathyroidism who underwent parathyroidectomy during the study period, 6 patients had genetically or clinically diagnosed MEN1 and 65 had sporadic non-MEN1 hyperparathyroidism. Most patients were women (MEN1: 4 [67%]; non-MEN1: 51 [78%]). Median (interquartile range) age was 49.0 (38.0-53.8) years in the MEN1 cohort and 61.0 (54.0-67.0) years in the non-MEN1 cohort. No clinically significant differences in serum preoperative parathyroid hormone level or parathyroid gland size or weight on pathologic examination were observed between the 2 cohorts. The median absolute value of in situ parathyroid autofluorescence was significantly lower in the MEN1 cohort than the non-MEN1 cohort (54.4 vs 74.3; Hedges g = -1.03; 95% CI, -1.89 to -0.17), as was the ratio of parathyroid to background autofluorescence (1.08 vs 1.59; g = -1.59; 95% CI, -2.23 to -0.96). Three patients (50%) with MEN1 had false-negative nonfluorescent parathyroid adenomas vs 6 patients (9%) without MEN1. Nonparathyroid fibroadipose tissue of patients with MEN1 exhibited greater background autofluorescence, leading to high false-positive rates (5 of 6 patients [83%]) vs only 3 of 65 (5%) false-positive autofluorescence nonparathyroid specimens among patients without MEN1.

Conclusions and Relevance

Intraoperative identification of parathyroid glands using their autofluorescence by real-time NIR imaging appears to have utility in patients with primary hyperparathyroidism. In this initial cohort of patients with MEN1, decreased parathyroid autofluorescence and increased background autofluorescence of nonparathyroid tissue may be associated with high rates of false-negative and false-positive fluorescence, potentially limiting the utility of this adjunct in this specific subset of patients.

Afirma Gene Sequencing Classifier Compared with Gene Expression Classifier in Indeterminate Thyroid Nodules

Background: The Afirma Gene Expression Classifier (GEC) has been used to further characterize cytologically indeterminate (cyto-I) thyroid nodules into either benign or suspicious categories. However, its relatively low positive predictive value (PPV) limited its use as a classifier for patients with suspicious results. The Afirma Gene Sequencing Classifier (GSC) was developed to improve PPV while maintaining a high negative predictive value (NPV), yet real-world assessment of its performance is lacking. Methods: We analyzed all patients who had cyto-I nodules and molecular testing with either GEC or GSC between 2011 and 2018 at a single academic medical center. Clinical information was obtained for 343 GEC-tested nodules and 164 GSC-tested nodules. Results: The GSC had a statistically significant higher benign call rate (76.2% vs. 48.1%, p < 0.001), PPV (60.0% vs. 33.3%, p = 0.01), and specificity (94.3% vs. 61.4%, p < 0.001) than the GEC. Improvement was statistically significant in both Bethesda III and Bethesda IV nodules. In particular, the benign call rate of GSC was significantly higher in nodules with Hürthle cell changes (88.8% vs. 25.7%, p < 0.01). The rate of surgical intervention in the indeterminate nodule cohort has decreased by 66.4% since switching to the GSC; 52.5% of indeterminate nodules went to surgery while using the GEC compared with 17.6% with the GSC (p < 0.001). This reduction was statistically significant in nodules with Bethesda III diagnoses, demonstrating a 70.9% decrease (GEC 51.3% vs. GSC 14.9%, p < 0.001), and in nodules with Bethesda IV cytology, a 39.2% decrease was noted (GEC 54.8% vs. GSC 33.3%, p = 0.003). Conclusions: Data from a single academic tertiary center show an improved specificity and PPV while maintaining high sensitivity and NPV for GSC compared with GEC. A statistically significant increase in benign call rates was observed in GSC compared with GEC, likely indicating fewer false positive results. After implementation of GSC, surgical interventions have been reduced by 68%.

Features of synchronous versus metachronous metastasectomy in adrenal cortical carcinoma: Analysis from the US adrenocortical carcinoma database

BACKGROUND

Adrenocortical carcinoma is a rare, aggressive cancer. We compared features of patients who underwent synchronous versus metachronous metastasectomy.

METHODS

Adult patients who underwent resection for metastatic adrenocortical carcinoma from 1993 to 2014 at 13 institutions of the US adrenocortical carcinoma group were analyzed retrospectively. Patients were categorized as synchronous if they underwent metastasectomy at the index adrenalectomy or metachronous if they underwent resection after recurrence of the disease. Factors associated with overall survival were assessed by univariate analysis.

RESULTS

In the study, 84 patients with adrenocortical carcinoma underwent metastasectomy; 26 (31%) were synchronous and 58 (69%) were metachronous. Demographics were similar between groups. The synchronous group had more T4 tumors at the index resection (42 vs 3%, P < .001). The metachronous group had prolonged median survival after the index resection (86.3 vs 17.3 months, P < .001) and metastasectomy (36.9 vs 17.3 months, P = .007). Synchronous patients with R0 resections had improved survival compared to patients with R1/2 resections (P = .008). Margin status at metachronous metastasectomy was not associated with survival (P = .452).

CONCLUSION

Select patients with metastatic adrenocortical carcinoma may benefit from metastasectomy. Patients with metachronous metastasectomy have a more durable survival benefit than those undergoing synchronous metastasectomy. This study highlights need for future studies examining differences in tumor biology that could explain outcome disparities in these distinct patient populations.

Microsatellite Instability Occurs in a Subset of Follicular Thyroid Cancers

BACKGROUND

Inactivation of DNA mismatch repair (MMR) and the resulting microsatellite instability (MSI) are frequently observed in endometrial, stomach, and colorectal cancers, as well as more rarely in other solid tumor types. The prevalence of MSI in thyroid cancer has not been explored in depth, although recent studies utilizing data from large cancer sequencing efforts such as The Cancer Genome Atlas indicate that MSI is absent or at least very rare in the most common and most well studied histologic subtype, papillary thyroid carcinoma. This study aimed to determine the prevalence of MSI in thyroid cancer by using a large series comprising all major histological subtypes.

METHODS

A total of 485 thyroid cancer patients were screened for MSI/MMR deficiency, including all major histologic subtypes (195 papillary thyroid carcinoma, 156 follicular thyroid carcinoma [FTC], 50 anaplastic thyroid carcinoma, 65 medullary thyroid carcinoma, and 17 poorly differentiated thyroid carcinomas) by using a combination of polymerase chain reaction-based detection, immunohistochemistry, and next-generation sequencing.

RESULTS

A total of four tumors were MSI-high and had loss of MMR protein expression, all of which were from FTC patients. Whole-exome sequencing was performed on two MSI-high FTCs and revealed a hemizygous loss of function mutation in MSH2 in one tumor.

CONCLUSIONS

Based on these data, it is estimated that the overall prevalence of MSI in FTC is 2.5%, and MSI is either entirely absent or rare in other histology subtypes of thyroid carcinoma. These findings highlight the importance of testing for MSI in FTC.

Developing a Clinical Prototype to Guide Surgeons for Intraoperative Label-Free Identification of Parathyroid Glands in Real Time

BACKGROUND

Patients undergoing thyroidectomy may have inadvertent damage or removal of the parathyroid gland(s) due to difficulty in real-time parathyroid identification. Near-infrared autofluorescence (NIRAF) has been demonstrated as a label-free modality for intraoperative parathyroid identification with high accuracy. This study presents the translation of that approach into a user-friendly clinical prototype for rapid intraoperative guidance in parathyroid identification.

METHODS

A laboratory (lab)-built spectroscopy system that measures NIRAF in tissue was evaluated for identifying parathyroid glands in vivo across 162 patients undergoing thyroidectomy and/or parathyroidectomy. Based on these results, a clinical prototype called PTeye was designed with a user-friendly interface and subsequently investigated in 35 patients. The performance of the lab-built system and the clinical prototype were concurrently compared side by side by a single user with 20 patients in each group. The influence of (i) intrapatient and interpatient variability of NIRAF in thyroid and parathyroid glands and (ii) thyroid and parathyroid pathology on intraoperative parathyroid identification were investigated. The effect of blood on NIRAF intensity of parathyroid and thyroid was tested ex vivo with the PTeye system to assess if a hemorrhagic surgical field would affect parathyroid identification. Accuracy of both systems were determined by correlating the acquired data with either visual confirmation by a surgeon for unexcised parathyroid glands or histology reports for excised parathyroid glands.

RESULTS

The overall accuracy of the lab-built system in guiding parathyroid identification was 92.5%, while the PTeye system achieved an accuracy of 96.1%. Unlike the lab-built system, the PTeye could guide parathyroid identification even as the operating room lights remained on and required only 25% of the laser power used by the lab-built setup. Parathyroid glands had elevated NIRAF intensity compared to thyroid and other neck tissues, regardless of thyroid or parathyroid pathology. Blood did not seem to affect tissue NIRAF measurements obtained with both systems.

CONCLUSION

In this study, the clinical prototype PTeye demonstrated high accuracy for label-free intraoperative parathyroid identification. The intuitive interface of the PTeye that can guide in identifying parathyroid tissue in the presence of ambient room lights suggests that it is a reliable and easy-to-use tool for surgical personnel.

Evidence of aldosterone synthesis in human myocardium in acute myocarditis

BACKGROUND

Myocarditis may be self-limited but has been identified as an important contributor to downstream cardiomyopathy. Aldosterone mediates myocardial damage in various conditions, but has not been considered specifically as a therapeutic target for inflammatory damage in acute myocarditis. We sought to demonstrate local aldosterone synthesis in human myocardium affected by acute myocarditis.

METHODS

We evaluated myocardial samples obtained via endomyocardial biopsy (EMB) for expression of CYP11B2, the final and key enzyme for aldosterone synthesis, from patients with acute myocarditis and from stable heart transplant recipients with no evidence of rejection as negative controls. Excised adrenal glands from patients with aldosterone-secreting adenomas were used as positive controls. An experienced cardiovascular pathologist blinded to clinical information rated CYP11B2 stains as negative, positive, or borderline, also recording location of any CYP11B2-positivity.

RESULTS

Sixteen patients' EMB samples showing definite acute myocarditis were identified (50% female). CYP11B2 was positive in 13/16 cases (81%), typically showing diffuse intracardiomyocyte cytoplasmic staining, vs. 2/16 borderline stains in transplant controls (p < 0.001 myocarditis vs. negative controls). All 3 adrenalectomy samples stained positive for CYP11B2 (diffuse intracellular staining). Importantly, no myocarditis or transplant patients were on aldosterone antagonist therapy at the time of biopsy.

CONCLUSIONS

In this proof-of-concept study, myocardium from patients with acute myocarditis demonstrates evidence and high prevalence of local aldosterone synthesis by immunohistochemistry that showed high accuracy, specificity, and sensitivity. Aldosterone warrants consideration as a specific target for therapy in patients with myocardial damage due to inflammation towards strategies that reduce downstream complications.

Identification of the Thoracic Duct Using Indocyanine Green During Cervical Lymphadenectomy

BACKGROUND

Injury to the thoracic duct (TD) is the most common complication after a left lateral neck dissection, and it carries a high degree of morbidity. Currently, no routine diagnostic imaging is used to assist with TD identification intraoperatively. This report describes the first clinical experience with lymphangiography using indocyanine green (ICG) during lateral neck dissections.

METHODS

In six patients undergoing left lateral neck dissection (levels 2-4) for either thyroid cancer or melanoma, 2.5-5 mg of ICG was injected in the dorsum of the left foot 15 min before imaging. Intraoperative imaging was performed with a hand-held near infrared (NIR) camera (Hamamatsu, PDE-Neo, Hamamatsu City, Japan).

RESULTS

In five patients, the TD was visualized using NIR fluorescence, with a time of 15-90 min from injection to identification. Imaging was optimized by positioning the camera at the angle of the mandible and pointing into the space below the clavicle. No adverse reactions from the ICG injection occurred, and the time required for imaging was 5-10 min. No intraoperative TD injury was identified, and no chyle leak occurred postoperatively. For the one patient in whom the TD was not identified, it is unclear whether this was related to the timing of the injection or to duct obliteration from a prior dissection.

CONCLUSION

This is the first described application of ICG lymphangiography to identify the thoracic duct during left lateral neck dissection. Identification of TD with ICG is technically feasible, simple to perform with NIR imaging, and safe, making it a potential important adjunct for the surgeon.

The Role of NRG1 in the Predisposition to Papillary Thyroid Carcinoma

Context

Previous genome-wide association studies have shown that single-nucleotide polymorphism (SNP) rs2439302 in chromosome 8p12 is significantly associated with papillary thyroid carcinoma (PTC) risk and dysregulated NRG1 expression. The underlying mechanisms remain to be discovered.

Objective

To evaluate the expression of NRG1 isoforms, candidate functional variants, and potential genes downstream of NRG1 in thyroid tissue.

Methods

Quantitative reverse transcription polymerase chain reaction was applied for gene expression analysis. SNaPshot assay, haplotype, and computer analyses were performed to evaluate candidate functional variants. Other functional assays [chromatin immunoprecipitation (ChIP) assay, luciferase assay, small interfering RNA knockdown, and RNA sequencing] were performed.

Results

Three NRG1 isoforms (NM_004495, NM_013958, and NM_001160008) tested were highly expressed in thyroid tissue. The expression levels of the three isoforms were significantly correlated with the genotypes of rs2439302. A DNA block of ~32 kb containing the risk G allele of rs2439302 was revealed, harboring multiple candidate functional variants. ChIP assay for active chromatin markers indicated at least nine regions in the DNA block showing strong H3Kme1 and H3K27Ac signals in thyroid tissue. Luciferase reporter assays revealed differential allelic activities associated with seven SNPs. Knocking down NRG1 in primary thyroid cells revealed downstream or interacting genes related to NRG1.

Conclusions

Our data suggest a role for transcriptional regulation of NRG1 in the predisposition to PTC.

The role of SMAD3 in the genetic predisposition to papillary thyroid carcinoma

PURPOSE

To identify and characterize the functional variants, regulatory gene networks, and potential binding targets of SMAD3 in the 15q22 thyroid cancer risk locus.

METHODS

We performed linkage disequilibrium (LD) and haplotype analyses to fine map the 15q22 locus. Luciferase reporter assays were applied to evaluate the regulatory effects of the candidate variants. Knockdown by small interfering RNA, microarray analysis, chromatin immunoprecipitation (ChIP) and quantitative real-time polymerase chain reaction assays were performed to reveal the regulatory gene network and identify its binding targets.

RESULTS

We report a 25.6-kb haplotype within SMAD3 containing numerous single-nucleotide polymorphisms (SNPs) in high LD. SNPs rs17293632 and rs4562997 were identified as functional variants of SMAD3 by luciferase assays within the LD region. These variants regulate SMAD3 transcription in an allele-specific manner through enhancer elements in introns of SMAD3. Knockdown of SMAD3 in thyroid cancer cell lines revealed its regulatory gene network including two upregulated genes, SPRY4 and SPRY4-IT1. Sequence analysis and ChIP assays validated the actual binding of SMAD3 protein to multiple SMAD binding element sites in the region upstream of SPRY4.

CONCLUSION

Our data provide a functional annotation of the 15q22 thyroid cancer risk locus.

A Novel T-Stage Classification System for Adrenocortical Carcinoma: Proposal from the US Adrenocortical Carcinoma Study Group

BACKGROUND

The 7th AJCC T-stage system for adrenocortical carcinoma (ACC), based on size and extra-adrenal invasion, does not adequately stratify patients by survival. Lymphovascular invasion (LVI) is a known poor prognostic factor. We propose a novel T-stage system that incorporates LVI to better risk-stratify patients undergoing resection for ACC.

METHOD

Patients undergoing curative-intent resections for ACC from 1993 to 2014 at 13 institutions comprising the US ACC Group were included. Primary outcome was disease-specific survival (DSS).

RESULTS

Of the 265 patients with ACC, 149 were included for analysis. The current T-stage system failed to differentiate patients with T2 versus T3 disease (p = 0.10). Presence of LVI was associated with worse DSS versus no LVI (36 mo vs. 168 mo; p = 0.001). After accounting for the individual components of the current T-stage system (size, extra-adrenal invasion), LVI remained a poor prognostic factor on multivariable analysis (hazard ratio 2.14, 95% confidence interval 1.05-4.38, p = 0.04). LVI positivity further stratified patients with T2 and T3 disease (T2: 37 mo vs. median not reached; T3: 36 mo vs. 96 mo; p = 0.03) but did not influence survival in patients with T1 or T4 disease. By incorporating LVI, a new T-stage classification system was created: [T1: ≤ 5 cm, (-)local invasion, (+/-)LVI; T2: > 5 cm, (-)local invasion, (-)LVI OR any size, (+)local invasion, (-)LVI; T3: > 5 cm, (-)local invasion, (+)LVI OR any size, (+)local invasion, (+)LVI; T4: any size, (+)adjacent organ invasion, (+/-)LVI]. Each progressive new T-stage group was associated with worse median DSS (T1: 167 mo; T2: 96 mo; T3: 37 mo; T4: 15 mo; p < 0.001).

CONCLUSIONS

Compared with the current T-stage system, the proposed T-stage system, which incorporates LVI, better differentiates T2 and T3 disease and accurately stratifies patients by disease-specific survival. If externally validated, this T-stage classification should be considered for future AJCC staging systems.

Biological Evaluation of a Fluorescent-Imaging Agent for Medullary Thyroid Cancer in an Orthotopic Model

Context

The primary and definitive treatment of medullary thyroid cancer (MTC) is surgical resection. Recurrent or residual disease is typically a result of incomplete surgical removal.

Objective

Our objective is to develop a compound that assists in intraoperative visualization of cancer, which would have the potential to improve surgical cure rates and outcomes.

Results

We report the biological characterization of Compound-17, which is labeled with IRdye800, allowing fluorescent visualization of MTC mouse models. We found that the agent has high affinity for two human MTC cell lines (TT and MZ-CRC1) in vitro and in vivo. We further tested the affinity of the compound in a newly developed MTC orthotopic xenograft model and found that Compound-17 produces fluorescent signals within MTC-derived orthotopic xenografts in comparison with a sequence-jumbled control compound and surrounding normal tissues.

Conclusions

Compound-17 is a unique and effective molecule for MTC identification that may have therapeutic potential.

Blood Transfusion and Survival for Resected Adrenocortical Carcinoma: A Study from the United States Adrenocortical Carcinoma Group

Perioperative blood transfusion is associated with decreased survival in pancreatic, gastric, and liver cancer. The effect of transfusion in adrenocortical carcinoma (ACC) has not been studied. Patients with available transfusion data undergoing curative-intent resection of ACC from 1993 to 2014 at 13 institutions comprising the United States Adrenocortical Carcinoma Group were included. Factors associated with blood transfusion were determined. Primary and secondary end points were recurrence-free survival (RFS) and overall survival (OS), respectively. Out of 265 patients, 149 were included for analysis. Out of these, 57 patients (38.3%) received perioperative transfusions. Compared to nontransfused patients, transfused patients more commonly had stage 4 disease (46% vs 24%, P = 0.01), larger tumors (15.8 vs 10.2 cm, P < 0.001), inferior vena cava involvement (24.6% vs 5.4%, P = 0.002), additional organ resection (78.9% vs 36.3%, P < 0.001), and major complications (29% vs 2%, P < 0.001). Transfusion was associated with decreased RFS (8.9 vs 24.7 months, P = 0.006) and OS (22.8 vs 91.0 months, P < 0.001). On univariate Cox regression, transfusion, stage IV, hormonal hypersecretion, and adjuvant therapy were associated with decreased RFS. On multivariable analysis, only transfusion [hazard ratio (HR) = 1.7, 95% confidence interval (CI) 51.0–2.9, P = 0.04], stage IV (HR = 3.2, 95% CI = 1.7–5.9, P < 0.001), and hormonal hypersecretion (HR = 2.6, 95% CI = 1.5–4.2, P < 0.001) were associated with worse RFS. When applying this model to OS, similar associations were seen (transfusion HR = 2.0, 95% CI = 1.1–3.8, P = 0.02; stage 4 HR = 6.2, 95% CI = 3.1–12.4, P < 0.001; hormonal hypersecretion HR = 3.5, 95% CI = 1.9–6.4, P < 0.001). There was no difference in outcomes between patients who received 1 to 2 units versus >2 units of packed red blood cells in median RFS (8.9 vs 8.4 months, P = 0.95) or OS (26.5 vs 18.6 months, P = 0.63). Peri-operative transfusion is associated with earlier recurrence and decreased survival after curative-intent resection of ACC. Strategies and protocols to minimize blood transfusion should be developed and followed.

Blood Transfusion and Survival for Resected Adrenocortical Carcinoma: A Study from the United States Adrenocortical Carcinoma Group

Perioperative blood transfusion is associated with decreased survival in pancreatic, gastric, and liver cancer. The effect of transfusion in adrenocortical carcinoma (ACC) has not been studied. Patients with available transfusion data undergoing curative-intent resection of ACC from 1993 to 2014 at 13 institutions comprising the United States Adrenocortical Carcinoma Group were included. Factors associated with blood transfusion were determined. Primary and secondary end points were recurrence-free survival (RFS) and overall survival (OS), respectively. Out of 265 patients, 149 were included for analysis. Out of these, 57 patients (38.3%) received perioperative transfusions. Compared to nontransfused patients, transfused patients more commonly had stage 4 disease (46% vs 24%, P = 0.01), larger tumors (15.8 vs 10.2 cm, P < 0.001), inferior vena cava involvement (24.6% vs 5.4%, P = 0.002), additional organ resection (78.9% vs 36.3%, P < 0.001), and major complications (29% vs 2%, P < 0.001). Transfusion was associated with decreased RFS (8.9 vs 24.7 months, P = 0.006) and OS (22.8 vs 91.0 months, P < 0.001). On univariate Cox regression, transfusion, stage IV, hormonal hypersecretion, and adjuvant therapy were associated with decreased RFS. On multivariable analysis, only transfusion [hazard ratio (HR) = 1.7, 95% confidence interval (CI) =1.0-2.9, P = 0.04], stage IV (HR = 3.2, 95% CI = 1.7-5.9, P < 0.001), and hormonal hypersecretion (HR = 2.6, 95% CI = 1.5-4.2, P < 0.001) were associated with worse RFS. When applying this model to OS, similar associations were seen (transfusion HR = 2.0, 95% CI = 1.1-3.8, P = 0.02; stage 4 HR = 6.2, 95% CI = 3.1-12.4, P < 0.001; hormonal hypersecretion HR = 3.5, 95% CI = 1.9-6.4, P < 0.001). There was no difference in outcomes between patients who received 1 to 2 units versus >2 units of packed red blood cells in median RFS (8.9 vs 8.4 months, P = 0.95) or OS (26.5 vs 18.6 months, P = 0.63). Perioperative transfusion is associated with earlier recurrence and decreased survival after curative-intent resection of ACC. Strategies and protocols to minimize blood transfusion should be developed and followed.

The Role of Central Neck Lymph Node Dissection in the Management of Papillary Thyroid Cancer

Papillary thyroid cancer (PTC) is the most common thyroid malignancy, and cervical nodal metastases are frequent at presentation. The most common site for nodal metastases from PTC is the central compartment of the ipsilateral neck in the paratracheal and pretracheal regions. The decision to resect these lymph nodes at the time of thyroidectomy often depends on if nodes with suspected malignancy can be identified preoperatively. If nodal spread to the central neck nodes is known, then the consensus is to remove all nodes in this area. However, there remains significant controversy regarding the utility of removing central neck lymph nodes for prophylactic reasons. Herein, we review the potential utility of central neck lymph node dissection as well as the risks of performing this procedure. As well, we review the potential of molecular testing to stratify patients who would most benefit from this procedure. We advocate a selective approach in which patients undergo clinical neck examination coupled with ultrasound to detect any concerning lymph nodes that warrant additional evaluation with either fine needle aspiration or excisional biopsy in the operating room. In lieu of clinical lymphadenopathy, we suggest the use of patient and disease characteristics as identified by multiple groups, such as the American Thyroid Association and European Society of Endocrine Surgeons, which include extremes of ages, large primary tumor size, and male gender, when deciding to perform central neck lymph node dissection. Patients should be educated on the potential long-terms risks versus the lack of known long-term benefits.

Outcomes of metastatic adrenocortical carcinoma (ACC): A 16-year single institutional experience

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Background: ACC is a rare malignancy with limited data to guide management of metastatic disease. Prior research regarding survival has focused on pts with locoregional disease, but has not offered insight into the management and outcomes of pts with metastatic disease. Methods: We retrospectively reviewed patients (pts) with metastatic ACC who were treated with systemic therapy between January 2000 and October 2016 at The Ohio State University Comprehensive Cancer Center. Kaplan-Meier and Cox proportional hazards regression models were used for survival analysis. Results: A total of 18 pts received systemic therapy for distant metastatic disease. Median age at diagnosis was 51 (range 31 – 72). Median overall survival (OS) from time of diagnosis of ACC was 15.5 months (95% CI 4.8 – 28.2), and from time of systemic treatment (ST) was 7.1 months (95% CI 3.3 – 26). A germline variant of uncertain significance in MSH2 (c.138C > G) was identified in one patient. Baseline FDG-PET scans were obtained in 11/18 pts, and demonstrated avidity in all patients. Maximum SUV ranged from 4.1 to 47.6, with a median of 15. First line therapy was etoposide, doxorubicin, cisplatin, and mitotane (EDPM) in 13/18 pts and clinical trial with IMC-A12 (IGF-1 receptor antibody) in four pts. Median duration of first line therapy was 1.8 months (95% CI 0.9 – 2.8). Survival was not statistically different for patients receiving EDPM as first or second line therapy (median OS 23.3 vs 12.0 months, p = 0.96). Additional lines of therapy included EDPM, IMC-A12, AT-101, mifepristone, OSI-906 (IGF-1R inhibitor), and nivolumab. Median lines of therapy given were 2. The presence of bone metastases (p = 0.69) or lung metastases (p = 0.21) at the time of initiation of ST was not associated with OS from ST. Conclusions: In our experience, the prognosis of pts with metastatic ACC receiving systemic therapy is poor with most pts receiving ≤ 2 lines of therapy. Patients receiving first or second line EDPM seemed to have worse outcomes than noted in previously published trials, possibly due to our patients being sicker at baseline. Metastasis to the lung or bone at initiation of ST did not impact OS.

A novel t-stage classification system for adrenocortical carcinoma: Proposal from the U.S. Adrenocortical Carcinoma Study Group

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Background: The 7th AJCC T-stage classification system for adrenocortical carcinoma (ACC), based on size and extra-adrenal invasion, does not adequately stratify patients by survival. Lymphovascular invasion (LVI) is a known poor prognostic factor. We propose a novel T-stage system that incorporates LVI to better risk-stratify patients undergoing resection for ACC. Methods: Patients undergoing curative-intent resections for ACC from 1993-2014 at 13 institutions comprising the US ACC Study Group were included. Primary outcome was disease-specific survival (DSS). Results: Of 265 patients with ACC, 149 had complete data for analysis. The current T-stage system failed to differentiate patients with T2 vs T3 disease ( p= 0.10). Presence of LVI was associated with worse DSS compared to no LVI (36 vs. 168mos; p= 0.001). After accounting for the individual components of the current T-stage system (size and extra-adrenal invasion), LVI persisted as a poor prognostic factor on multivariable analysis (HR 2.14, 95% CI 1.05-4.38, p= 0.04). LVI positivity further stratified patients with T2 and T3 disease, (T2: 37mos vs median not reached; T3: 36 vs 96mos; p =0.03), but did not influence survival in patients with T1 or T4 disease. By incorporating LVI, a new T-stage classification system was created: [T1: < 5cm, (-)local invasion, (+/-)LVI; T2: > 5cm, (-)local invasion, (-)LVI OR any size, (+)local invasion, (-)LVI; T3: > 5cm, (-)local invasion, (+)LVI OR any size, (+)local invasion, (+)LVI; T4: any size, (+)adjacent organ invasion, (+/-)LVI]. Each progressive new T-stage group was associated with worse median DSS (T1: 167mos; T2: 96mos; T3: 37mos; T4: 15mos; p< 0.001). Conclusions: The current AJCC T-stage system for ACC does not adequately stratify patients by survival, particularly for T2 and T3 disease. The proposed T-stage classification system, which incorporates lymphovascular invasion, better differentiates T2 and T3 disease and accurately stratifies patients by disease-specific survival. If externally validated, this novel T-stage classification should be considered for future AJCC staging systems.

Minimally Invasive Resection of Adrenocortical Carcinoma: a Multi-Institutional Study of 201 Patients

BACKGROUND AND OBJECTIVES

Minimally invasive surgery for adrenocortical carcinoma (ACC) is controversial. We sought to evaluate the perioperative and long-term outcomes following minimally invasive (MIS) and open resection (OA) of ACC in patients treated with curative intent surgery.

METHODS

Retrospective data from patients who underwent adrenalectomy for primary ACC at 13 tertiary care cancer centers were analyzed, including demographics, clinicopathological, and operative outcomes. Outcomes following MIS were compared to OA.

RESULTS

A total of 201 patients were evaluated including 47 MIS and 154 OA. There was no difference in utilization of MIS approach among institutions (p = 0.24) or 30-day morbidity (29.3 %, MIS, vs. 30.9 %, OA; p = 0.839). The only preoperatively determined predictor for MIS was smaller tumor size (p < 0.001). There was no difference in rates of intraoperative tumor rupture (p = 0.612) or R0 resection (p = 0.953). Only EBL (p = 0.038) and T stage (p = 0.045) were independent prognostic indicators of overall survival after adjusting for significant factors. The surgical approach was not associated with overall or disease-free survival.

CONCLUSION

MIS adrenalectomy may be utilized for preoperatively determined ACC ≤ 10.0 cm; however, OA should be utilized for adrenal masses with either preoperative or intraoperative evidence of local invasion or enlarged lymph nodes, regardless of size.

Actual 10-year survivors following resection of adrenocortical carcinoma

BACKGROUND

Adrenocortical carcinoma (ACC) is a rare and aggressive malignancy with limited therapeutic options beyond surgical resection. The characteristics of actual long-term survivors following surgical resection for ACC have not been previously reported.

METHOD

Patients who underwent resection for ACC at one of 13 academic institutions participating in the US Adrenocortical Carcinoma Group from 1993 to 2014 were analyzed. Patients were stratified into four groups: early mortality (died within 2 years), late mortality (died within 2-5 years), actual 5-year survivor (survived at least 5 years), and actual 10-year survivor (survived at least 10 years). Patients with less than 5 years of follow-up were excluded.

RESULTS

Among the 180 patients available for analysis, there were 49 actual 5-year survivors (27%) and 12 actual 10-year survivors (7%). Patients who experienced early mortality had higher rates of cortisol-secreting tumors, nodal metastasis, synchronous distant metastasis, and R1 or R2 resections (all P < 0.05). The need for multi-visceral resection, perioperative blood transfusion, and adjuvant therapy correlated with early mortality. However, nodal involvement, distant metastasis, and R1 resection did not preclude patients from becoming actual 10-year survivors. Ten of twelve actual 10-year survivors were women, and of the seven 10-year survivors who experienced disease recurrence, five had undergone repeat surgery to resect the recurrence.

CONCLUSION

Surgery for ACC can offer a 1 in 4 chance of actual 5-year survival and a 1 in 15 chance of actual 10-year survival. Long-term survival was often achieved with repeat resection for local or distant recurrence, further underscoring the important role of surgery in managing patients with ACC. J. Surg. Oncol. 2016;114:971-976. © 2016 Wiley Periodicals, Inc.

Incidence of Perioperative Complications Following Resection of Adrenocortical Carcinoma and Its Association with Long-Term Survival

BACKGROUND

The association of postoperative complications with long-term oncologic outcomes remains unclear. We sought to determine the incidence of complications among patients who underwent surgery for adrenocortical carcinoma (ACC) and define the relationship of morbidity with long-term survival.

METHODS

Patients who underwent surgery for ACC between 1993 and 2014 were identified from 13 academic institutions participating in the US ACC group study. The incidence and type of the postoperative complications, the factors associated with them as well their association with long-term survival were analyzed.

RESULTS

A total of 265 patients with median age of 52 years (IQR 44-63) were identified; at surgery, the majority of patients underwent an open abdominal procedure (n = 169, 66.8%). A postoperative complication occurred in 99 patients for a morbidity of 37.4%; five patients (1.9%) died in hospital. Factors associated with morbidity included a thoraco-abdominal operative approach (reference: open abdominal; OR 2.85, 95% CI 1.00-8.18), and a hormonally functional tumor (OR 3.56, 95% CI 1.65-7.69) (all P < 0.05). Presence of any complication was associated with a worse long-term outcome (median survival: no complication, 58.9 months vs. any complication, 25.1 months; P = 0.009). In multivariate analysis, after adjusting for patient- and disease-related factors postoperative infectious complications independently predicted shorter overall survival (hazard ratio (HR) 5.56, 95% CI 2.24-13.80; P < 0.001).

CONCLUSION

Postoperative complications were independently associated with decreased long-term survival after resection for ACC. The prevention of complications may be important from an oncologic perspective.

Nomograms to Predict Recurrence-Free and Overall Survival After Curative Resection of Adrenocortical Carcinoma

IMPORTANCE

Adrenocortical carcinoma (ACC) is a rare but aggressive endocrine tumor, and the prognostic factors associated with long-term outcomes after surgical resection remain poorly defined.

OBJECTIVES

To define clinicopathological variables associated with recurrence-free survival (RFS) and overall survival (OS) after curative surgical resection of ACC and to propose nomograms for individual risk prediction.

DESIGN, SETTING, AND PARTICIPANTS

Nomograms to predict RFS and OS after surgical resection of ACC were proposed using a multi-institutional cohort of patients who underwent curative-intent surgery for ACC at 13 major institutions in the United States between March 17, 1994, and December 22, 2014. The dates of our study analysis were April 15, 2015, to May 12, 2015.

MAIN OUTCOMES AND MEASURES

The discriminative ability and calibration of the nomograms to predict RFS and OS were tested using C statistics, calibration plots, and Kaplan-Meier curves.

RESULTS

In total, 148 patients who underwent surgery for ACC were included in the study. The median patient age was 53 years, and 65.5% (97 of 148) of the patients were female. One-third of the patients (35.1% [52 of 148]) had a functional tumor, and the median tumor size was 11.2 cm. Most patients (77.7% [115 of 148]) underwent R0 resection, and 8.8% (13 of 148) of the patients had N1 disease. Using backward stepwise selection of clinically important variables with the Akaike information criterion, the following variables were incorporated in the prediction of RFS: tumor size of at least 12 cm (hazard ratio [HR], 3.00; 95% CI, 1.63-5.70; P < .001), positive nodal status (HR, 4.78; 95% CI, 1.47-15.50; P = .01), stage III/IV (HR, 1.80; 95% CI, 0.95-3.39; P = .07), cortisol-secreting tumor (HR, 2.38; 95% CI, 1.27-4.48; P = .01), and capsular invasion (HR, 1.96; 95% CI, 1.02-3.74; P = .04). Factors selected as predicting OS were tumor size of at least 12 cm (HR, 1.78; 95% CI, 1.00-3.17; P = .05), positive nodal status (HR, 5.89; 95% CI, 2.05-16.87; P = .001), and R1 margin (HR, 2.83; 95% CI, 1.51-5.30; P = .001). The discriminative ability and calibration of the nomograms revealed good predictive ability as indicated by the C statistics (0.74 for RFS and 0.70 for OS).

CONCLUSIONS AND RELEVANCE

Independent predictors of survival and recurrence risk after curative-intent surgery for ACC were selected to create nomograms predicting RFS and OS. The nomograms were able to stratify patients into prognostic groups and performed well on internal validation.

Clinical Score Predicting Long-Term Survival after Repeat Resection for Recurrent Adrenocortical Carcinoma

BACKGROUND

Adrenocortical carcinoma (ACC) is an aggressive malignancy typically resistant to chemotherapy and radiation. Surgery, even in the setting of locally recurrent or metastatic disease, remains the only potentially curative option. However, the subset of patients who will benefit from repeat resection in this setting remains ill defined. The objective of this study was to propose a prognostic clinical score that facilitates selection of patients for repeat resection of recurrent ACC.

STUDY DESIGN

Patients who underwent curative-intent repeat resection for recurrent ACC at 1 of 13 academic medical centers participating in the US ACC Study Group were identified. End points included morbidity, mortality, and overall survival.

RESULTS

Fifty-six patients underwent repeat curative-intent resection for recurrent ACC (representing 21% of 265 patients who underwent resection for primary ACC) from 1997 to 2014. Median age was 52 years. Sites of resected recurrence included locoregional only (54%), lung only (14%), liver only (12%), combined locoregional and lung (4%), combined liver and lung (4%), and other distant sites (12%). Thirty-day morbidity and mortality rates were 40% and 5.4%, respectively. Cox regression analysis revealed that the presence of multifocal recurrence, disease-free interval <12 months, and extrapulmonary distant metastases were independent predictors of poor survival. A clinical score consisting of 1-point each for the 3 variables demonstrated good discrimination in predicting survival after repeat resection (5-year: 72% for 0 points, 32% for 1 point, 0% for 2 or 3 points; p = 0.0006, area under the curve = 0.78).

CONCLUSIONS

Long-term survival after repeat resection for recurrent ACC is feasible when 2 of the following factors are present: solitary tumor, disease-free interval >12 months, and locoregional or pulmonary recurrence.

Lymphadenectomy for Adrenocortical Carcinoma: Is There a Therapeutic Benefit?

BACKGROUND

Lymph node metastasis is an established predictor of poor outcome for adrenocortical carcinoma (ACC); however, routine lymphadenectomy during surgical resection of ACC is not widely performed and its therapeutic role remains unclear.

METHODS

Patients undergoing margin-negative resection for localized ACC were identified from a multi-institutional database. Patients were stratified into 2 groups based on the surgeon's effort or not to perform a lymphadenectomy as documented in the operative note. Clinical, pathologic, and outcome data were compared between the 2 groups.

RESULTS

Of 120 patients who met inclusion criteria from 1993 to 2014, 32 (27 %) underwent lymphadenectomy. Factors associated with lymphadenectomy were tumor size (12 vs. 9.5 cm; p = .007), palpable mass at presentation (26 vs. 12 %; p = .07), suspicious lymph nodes on preoperative imaging (44 vs. 7 %; p < .001), and need for multivisceral resection (78 vs. 36 %; p < .001). Median number of lymph nodes harvested was higher in the lymphadenectomy group (5.5 vs. 0; p < .001). In-hospital mortality (0 vs. 1.3 %; p = .72) and grade 3/4 complication rates (0 vs. 12 %; p = .061) were not significantly different. Patients who underwent lymphadenectomy had improved overall survival (5-year 76 vs. 59 %; p = .041). The benefit of lymphadenectomy on overall survival persisted on multivariate analysis (HR = 0.17; p = .006) controlling for adverse preoperative and intraoperative factors associated with lymphadenectomy, such as tumor size, palpable mass, irregular tumor edges, suspicious nodes on imaging, and multivisceral resection.

CONCLUSIONS

In this multicenter study of adrenocortical carcinoma patients undergoing R0 resection, the surgeon's effort to dissect peritumoral lymph nodes was independently associated with improved overall survival.

Primary Cell Culture Systems for Human Thyroid Studies

BACKGROUND

Cell models are key instruments for in vitro studies of the thyroid. Permanent thyroid cell lines that are widely used in laboratory research typically originate from tumors. For many purposes, it is desirable to compare tumor cells with cells originating from normal tissue. However, such cultures grow slowly, have a highly limited life-span, and are known to lose their thyroid characteristics. The aim of the present study was to type coding and noncoding thyroid markers in different culture systems in an attempt to determine the optimal conditions for in vitro experimentation.

METHODS

Human primary thyroid cells were isolated from histologically non-tumorous tissues. Two alternative media (6H and h7H) were used. The morphology and behavior of the ensuing monolayer (two-dimensional) cultures was monitored by microscopy. The expression of key thyroid-related genes (n = 9) was monitored by reverse transcription polymerase chain reaction on days 8, 21, and 43 after initiation. As a pilot study, the same markers were studied in a three-dimensional hanging-drop culture system.

RESULTS

In the cultures with 6H or h7H medium, the primary thyroid cells displayed growth in numbers and size. Most cells retained the main morphological characteristics of thyroid cells throughout the first two weeks of culture, and fibroblast-like cells appeared around day 19. By day 21, most thyroid gene markers were retained, but by day 43, several markers were no longer present. The lncRNA transcripts PTCSC2 (spliced) and PTCSC3 were the first to disappear. There were no fundamental differences between the two media in the early period of culture. In the three-dimensional system, most thyroid markers were retained by day 21.

CONCLUSION

Cultures of thyroid cells retain many thyroid characteristics up to day 21. Thereafter, fibroblast-like dedifferentiated cells begin to dominate.

Outcomes of Adjuvant Mitotane after Resection of Adrenocortical Carcinoma: A 13-Institution Study by the US Adrenocortical Carcinoma Group

BACKGROUND

Current treatment guidelines recommend adjuvant mitotane after resection of adrenocortical carcinoma with high-risk features (eg, tumor rupture, positive margins, positive lymph nodes, high grade, elevated mitotic index, and advanced stage). Limited data exist on the outcomes associated with these practice guidelines.

STUDY DESIGN

Patients who underwent resection of adrenocortical carcinoma from 1993 to 2014 at the 13 academic institutions of the US Adrenocortical Carcinoma Group were included. Factors associated with mitotane administration were determined. Primary end points were recurrence-free survival (RFS) and overall survival (OS).

RESULTS

Of 207 patients, 88 (43%) received adjuvant mitotane. Receipt of mitotane was associated with hormonal secretion (58% vs 32%; p = 0.001), advanced TNM stage (stage IV: 42% vs 23%; p = 0.021), adjuvant chemotherapy (37% vs 5%; p < 0.001), and adjuvant radiation (17% vs 5%; p = 0.01), but was not associated with tumor rupture, margin status, or N-stage. Median follow-up was 44 months. Adjuvant mitotane was associated with decreased RFS (10.0 vs 27.9 months; p = 0.007) and OS (31.7 vs 58.9 months; p = 0.006). On multivariable analysis, mitotane was not independently associated with RFS or OS, and margin status, advanced TNM stage, and receipt of chemotherapy were associated with survival. After excluding all patients who received chemotherapy, adjuvant mitotane remained associated with decreased RFS and similar OS; multivariable analyses again showed no association with recurrence or survival. Stage-specific analyses in both cohorts revealed no association between adjuvant mitotane and improved RFS or OS.

CONCLUSIONS

When accounting for stage and adverse tumor and treatment-related factors, adjuvant mitotane after resection of adrenocortical carcinoma is not associated with improved RFS or OS. Current guidelines should be revisited and prospective trials are needed.

Outcomes after resection of cortisol-secreting adrenocortical carcinoma

BACKGROUND

We sought to define the impact of cortisol-secreting status on outcomes after surgical resection of adrenocortical carcinoma (ACC).

METHODS

The U.S ACC group database was queried to identify patients who underwent ACC resection between 1993 and 2014. The short-term and long-term outcomes were assessed.

RESULTS

The incidence of all functional and cortisol-secreting tumors was 40.6% and 22.6%, respectively. On multivariable analysis, cortisol secretion remained associated with an increased risk of postoperative complications (odds ratio = 2.25, 95 % confidence interval = 1.04 to 4.88; P = .04). At a median follow-up of 17.6 months, 118 patients (50.4%) had developed a recurrence. On multivariable analysis, after adjusting for patient and disease-related factors cortisol secretion independently predicted shorter recurrence-free survival (Hazard ratio = 2.05, 95% confidence interval = 1.16 to 3.60; P = .01).

CONCLUSIONS

Cortisol secretion was associated with an increased risk of postoperative morbidity. Recurrence remains high among patients with ACC after surgery; cortisol secretion was independently associated with a shorter recurrence-free survival. Tailoring postoperative surveillance of ACC patients based on their cortisol secreting status may be important.

Adrenocortical Carcinoma: Impact of Surgical Margin Status on Long-Term Outcomes

BACKGROUND

The influence of surgical margin status on long-term outcomes of patients undergoing adrenal resection for ACC remains not well defined. We studied the impact of surgical tumor margin status on recurrence-free survival (RFS) and overall survival (OS) of patients undergoing resection for ACC.

METHODS

A total of 165 patients who underwent adrenal resection for ACC and met inclusion criteria were identified form a multi-institutional database. Clinicopathological data, pathologic margin status, and long-term outcomes were assessed. Patients were stratified into two groups based on margin status: R0 (margin >1 mm) versus R1.

RESULTS

R0 resection was achieved in 126 patients (76.4 %), whereas 39 patients (23.6 %) had an R1 resection. Median and 5-year OS for patients undergoing R0 resection were 96.3 months and 64.8 % versus 25.1 months and 33.8 % for patients undergoing an R1 resection (both p < 0.001). On multivariable analysis, surgical margin status was an independent predictor of worse OS (hazard ratio [HR] 2.22, 95 % confidence interval [CI] 1.03-4.77; p = 0.04). The incidence of recurrence also differed between the two groups; 5-year RFS was 30.3 % among patients with an R0 resection versus 13.8 % among patients who had an R1 resection (p = 0.03). Lymph node metastasis (N1) was an independent predictor of RFS (HR 2.70, 95 % CI 1.04-6.99; p = 0.04).

CONCLUSIONS

A positive margin after ACC resection was associated with worse long-term survival. Patient selection and an emphasis on surgical technique to achieve R0 margins are pivotal to optimizing the best chance for long-term outcome among patients with ACC.

Curative Resection of Adrenocortical Carcinoma: Rates and Patterns of Postoperative Recurrence

BACKGROUND

Adrenocortical carcinoma (ACC) is a rare malignancy. The aim of this study was to determine the incidence and patterns of recurrence after curative-intent surgery for ACC.

METHODS

Patients who underwent curative-intent resection for ACC between 1993 and 2014 were identified from 13 academic institutions participating in the United States ACC study group. Patients with metastasis or an R2 margin were excluded. Patterns and rates of recurrence were determined and classified as locoregional and distant recurrence.

RESULTS

A total of 180 patients with a median age of 52 years (interquartile range 43-61) were identified. Most patients underwent open surgery (n = 111, 64.5 %) and had an R0 resection margin (n = 117, 75.0 %). At last follow-up, 116 patients (64.4 %) had experienced recurrence (locoregional only, n = 41, 36.3 %; distant only, n = 51, 45.1 %; locoregional and distant, n = 21, 18.6 %). Median time to recurrence was 18.8 months. Several factors were associated with locoregional recurrence, including left-sided ACC location (odds ratio [OR] 2.71, 95 % confidence interval [CI] 1.06-6.89) and T3/T4 disease (reference T1/T2, OR 3.04, 95 % CI 1.19-7.80) (both p < 0.05). Distant recurrence was associated with larger tumor size (OR 1.11, 95 % CI 1.01-1.24) and T3/T4 disease (reference T1/T2, OR 5.23, 95 % CI 1.70-16.10) (both p < 0.05). Patients with combined locoregional and distant recurrence had worse survival (3- and 5-year survival: 39.5, 19.7 %) versus patients with distant-only (3- and 5-year survival 55.1, 43.3 %) or locoregional-only recurrence (3- and 5-year survival 81.4, 64.1 %) (p = 0.01).

CONCLUSIONS

Nearly two-thirds of patients experienced disease recurrence after resection of ACC. Although a subset of patients experienced recurrence with locoregional disease only, many patients experienced recurrence with distant disease as a component of recurrence and had a poor prognosis.

Neutrophil-lymphocyte and platelet-lymphocyte ratio as predictors of disease specific survival after resection of adrenocortical carcinoma

BACKGROUND

The systemic inflammatory response may be associated with tumor progression. We sought to analyze the impact of neutrophil-lymphocyte ratio (NLR) and platelet-lymphocyte ratio (PLR) on recurrence-free survival (RFS) and disease-specific survival (DSS) among patients who underwent surgery for adrenocortical carcinoma (ACC).

METHODS

Patients undergoing surgery for ACC were identified from a multi-center database. Cut-off values of 5 and 190 were defined as elevated NLR and PLR, respectively, and long-term outcome was assessed.

RESULTS

Among 84 patients with ACC, 29 (34.%) had NLR > 5 while 32 (40.5%) had PLR > 190. NLR and PLR were associated with larger tumors (NLR > 5: ≤ 5 cm, 0% vs. >5 cm, 39.7%; PLR > 190: ≤ 5cm, 0% vs. >5 cm, 45.7%), as well as need to resect of other organs (NLR > 5: other organ resected 48.8% vs. not resected 20.9%; PLR > 190: other organ resected 25.0% vs. not resected 56.4%)(all P < 0.05). Five-year RFS was associated with an elevated NLR (NLR ≤ 5, 14.2% vs. NLR> 5, 10.5%) and PLR (PLR ≤ 190: 19.4% vs. PLR > 190: 5.2%) (both P < 0.05). On multivariate survival analyses, PLR remained a predictor of RFS (HR 1.72), while NLR was associated with both DSS (HR 2.21) and RFS (HR 1.99) (both P < 0.05).

CONCLUSIONS

Immune markers such as NLR and PLR may be useful to stratify patients with regards to prognosis following surgery for ACC.

A novel dual AMPK activator/mTOR inhibitor inhibits thyroid cancer cell growth

CONTEXT

Activated AMP protein kinase (AMPK) is a key regulator of intracellular energy homeostasis and may also function as a tumor suppressor by inhibiting cell growth through suppression of mammalian target of rapamycin (mTOR)/p70S6K signaling. AMPK activating agents, such as metformin and 5-aminoimidazole-4-carboxamide-ribonucleoside, have been demonstrated to inhibit thyroid cancer cell growth in in vitro and in vivo models. OSU-53, a recently developed AMPK activator, was previously shown to exhibit both in vitro and in vivo antitumor activity against aggressive breast cancer cell lines and their xenografts in nude mice.

OBJECTIVE

The objective of the study was to assess the in vitro effects of OSU-53 treatment in a panel of thyroid cancer cells.

DESIGN

Experiments were performed to determine the effects of OSU-53 on cell growth, oncogenic signaling, apoptosis, autophagy, and cell rescue after selective knockdown of AMPK.

RESULTS

OSU-53 inhibited in vitro cell growth of all seven thyroid cancer cells tested and induced activation of AMPK. Cell lines with activating mutations in RAS or BRAF, compared with cells with phosphatase and tensin homolog deleted from chromosome 10 null and RET/papillary thyroid carcinoma mutations, were more sensitive to drug treatment and demonstrated a more robust AMPK activation, inhibition of mTOR signaling, and autophagy stimulation. After selective knockdown of AMPK, cell rescue from OSU-53 treatment was not observed. We demonstrated an off-target effect of direct mTOR inhibition by OSU-53. Increased autophagy was observed in cells with activation RAS or BRAF mutations.

CONCLUSIONS

OSU-53, a novel dual-AMPK activator/mTOR inhibitor, effectively inhibits growth in a variety of thyroid cancer cell lines and is most potent in cells with activating mutations in RAS or BRAF.

Label-free intraoperative parathyroid localization with near-infrared autofluorescence imaging

CONTEXT

The inability to accurately localize the parathyroid glands during parathyroidectomy and thyroidectomy procedures can prevent patients from achieving postoperative normocalcemia. There is a critical need for an improved intraoperative method for real-time parathyroid identification.

OBJECTIVE

The objective of the study was to test the accuracy of a real-time, label-free technique that uses near-infrared (NIR) autofluorescence imaging to localize the parathyroid.

SETTING

The study was conducted at the Vanderbilt University endocrine surgery center.

SUBJECTS AND METHODS

Patients undergoing parathyroidectomy and/or thyroidectomy were included in this study. To validate the intrinsic fluorescence signal in parathyroid, point measurements from 110 patients were collected using NIR fluorescence spectroscopy. Fluorescence imaging was performed on 6 patients. Imaging contrast is based on a previously unreported intrinsic NIR fluorophore in the parathyroid gland. The accuracy of fluorescence imaging was analyzed in comparison with visual assessment and histological findings.

MAIN OUTCOME MEASURE

The detection rate of parathyroid glands was measured.

RESULTS

The parathyroid glands in 100% of patients measured with fluorescence imaging were successfully detected in real time. Fluorescence images consistently showed 2.4 to 8.5 times higher emission intensity from the parathyroid than surrounding tissue. Histological validation confirmed that the high intrinsic fluorescence signal in the parathyroid gland can be used to localize the parathyroid gland regardless of disease state.

CONCLUSION

NIR fluorescence imaging represents a highly sensitive, real-time, label-free tool for parathyroid localization during surgery. The elegance and effectiveness of NIR autofluorescence imaging of the parathyroid gland makes it highly attractive for clinical application in endocrine surgery.

Metastatic mechanisms in follicular cell-derived thyroid cancer

Thyroid cancer incidence is rising annually largely related to enhanced detection and early stage well-differentiated primary tumors. The prognosis for patients with early stage thyroid cancer is outstanding with most patients being cured with surgery. In selected cases, I-131 is administered to treat known or suspected residual or metastatic disease. Even patients with loco-regional metastases typically have an outstanding long-term prognosis, albeit with monitoring and occasional intervention for residual or recurrent disease. By contrast, individuals with distant metastases from thyroid cancer, particularly older patients with larger metastatic burdens and those with poorly differentiated tumors, have a poor prognosis. Patients with metastatic anaplastic thyroid cancer have a particularly poor prognosis. Published clinical trials indicate that transient disease control and partial remissions can be achieved with kinase inhibitor therapy directed toward angiogenic targets and that in some cases I-131 uptake can be enhanced. However, the direct targets of activity in metastatic lesions are incompletely defined and clear evidence that these treatments increase the duration or quality of life of patients is lacking, underscoring the need for improved knowledge regarding the metastatic process to inform the development of new therapies. In this review, we will focus on current data and hypotheses regarding key regulators of metastatic dormancy, metastatic progression, and the role of putative cancer stem cells.

A novel optical approach to intraoperative detection of parathyroid glands

BACKGROUND

Inadvertent removal of parathyroid glands is a challenge in endocrine operations. There is a critical need for a diagnostic tool that provides sensitive, real-time parathyroid detection during procedures. We have developed an intraoperative technique using near-infrared (NIR) fluorescence for in vivo, real-time detection of the parathyroid regardless of its pathologic state.

METHODS

NIR fluorescence was measured intraoperatively from 45 patients undergoing parathyroidectomy and thyroidectomy. Spectra were measured from the parathyroid and surrounding neck tissues during the operation with the use of a portable, probe-based fluorescence system at 785-nm excitation. Accuracy was evaluated by comparison with histology or visual recognition by the surgeon.

RESULTS

NIR fluorescence detected the parathyroid in 100% of patients. Parathyroid fluorescence was stronger (1.2-18 times) than that of the thyroid with peak fluorescence at 822 nm. Surrounding tissues showed no auto-fluorescence. Disease state did not affect the ability to discriminate parathyroid glands but may account for signal variability.

CONCLUSION

NIR fluorescence spectroscopy can detect intraoperatively the parathyroid regardless of tissue pathology. The signal may be caused by calcium-sensing receptors present in the parathyroid. The signal strength and consistency indicates the simplicity and effectiveness of this method. Its implementation may limit operative time, decrease costs, and improve operative success rates.

Development of a calcium-sensing receptor molecular imaging agent

BACKGROUND

Calcium-sensing receptor (CaSR) is expressed by parathyroid cells and thyroid C-cells (from which medullary thyroid carcinoma [MTC] is derived). A molecular imaging agent localizing to the CaSR could improve the detection of parathyroids and MTC preoperatively or intraoperatively. We synthesized a novel compound containing a fluorine residue for potential future labeling and demonstrated that the compound inhibited CaSR function in vitro.

METHODS

We synthesized compound M, a derivative of a known calcilytic compound, Calhex-231. Human embryonic kidney cells transfected with green-fluorescent protein-tagged CaSR or control vector were preincubated with compound M before the addition of calcium. Immunoblotting for total mitogen-activated protein kinase (MAPK: ERK1/2), activated MAPK (phosphorylated ERK1/2), and glyceraldehyde 3-phosphate dehydrogenase was performed.

RESULTS

Synthesis of compound M was confirmed by mass spectrometry. Inhibition of the MAPK signaling pathway by compound M was demonstrated in a dose-dependent manner by a decrease in phosphorylated ERK1/2 with no change in total ERK1/2 levels. Compound M inhibited MAPK signaling slightly better than the parent compound.

CONCLUSION

We have developed a novel molecule which demonstrates functional inhibition of CaSR and has a favorable structure for labeling. This compound appears to be appropriate for further development as a molecular imaging tool to enhance the surgical treatment of parathyroid disease and MTC.