Can Ethanol Ablation Achieve Durable Control of Neck Nodal Recurrences in Adults With Stage I Papillary Thyroid Cancer?

Objective: Results of ethanol ablation (EA) for controlling neck nodal metastases (NNM) in adult patients with papillary thyroid carcinoma (APTC) beyond 6 months have rarely been reported. We now describe outcome results in controlling 71 NNM in 40 node-positive stage I APTC patients followed for 66 to 269 months. Methods: All 40 patients were managed with bilateral thyroidectomy and radioiodine therapy and followed with neck ultrasound (US) for >48 months after EA. Cumulative radioiodine doses ranged from 30 to 550 mCi; pre-EA 27 patients (67%) had 36 additional neck surgeries. Cytologic diagnosis of PTC in 71 NNM selected for EA was confirmed by US-guided biopsy. EA technique and follow-up protocol were as previously described. Results: The 40 patients had 1 to 4 NNM; 67/71 NNM (94%) received 2 to 4 ethanol injections (total median volume 0.8 cc). All ablated 71 NNM shrank (mean volume reduction of 93%); nodal hypervascularity was eliminated. Thirty-eight NNM (54%) with initial volumes of 12-1404 mm3 (median 164) disappeared on neck sonography. Thirty-three hypovascular foci from ablated NNM (pre-EA volume range 31-636 mm3; median 147) were still identifiable with volume reductions of 45% to 97% observed (median 81%). There were no complications and no postprocedure hoarseness. Final results were considered to be ideal or near ideal in 55% and satisfactory in 45%. There was no evidence of tumor regrowth after EA. Conclusion: Our results demonstrate that for patients with American Joint Committee on Cancer stage I APTC, who do not wish further surgery or radioiodine, and are uncomfortable with active surveillance, EA can achieve durable control of recurrent NNM.

Post-COVID-19 vaccination myocarditis: a prospective cohort study pre and post vaccination using cardiovascular magnetic resonance.

BACKGROUND: Concerns about COVID-19 vaccination induced myocarditis or subclinical myocarditis persists in some populations. Cardiac magnetic resonance imaging (CMR) has been used to detect signs of COVID-19 vaccination induced myocarditis. This study aims to: (i) characterise myocardial tissue, function, size before and after COVID-19 vaccination, (ii) determine if there is imaging evidence of subclinical myocardial inflammation or injury after vaccination using CMR. METHODS: Subjects aged ≥ 12yrs old without prior COVID-19 or COVID-19 vaccination underwent two CMR examinations: first, ≤ 14 days before the first COVID-19 vaccination and a second time ≤ 14 days after the second COVID-19 vaccination. Biventricular indices, ejection fraction (EF), global longitudinal strain (GLS), late gadolinium enhancement (LGE), left ventricular (LV) myocardial native T1, T2, extracellular volume (ECV) quantification, lactate dehydrogenase (LDH), white cell count (WCC), C-reactive protein (CRP), NT-proBNP, troponin-T, electrocardiogram (ECG), and 6-min walk test were assessed in a blinded fashion. RESULTS: 67 subjects were included. First and second CMR examinations were performed a median of 4 days before the first vaccination (interquartile range 1-8 days) and 5 days (interquartile range 3-6 days) after the second vaccination respectively. No significant change in global native T1, T2, ECV, LV EF, right ventricular EF, LV GLS, LGE, ECG, LDH, troponin-T and 6-min walk test was demonstrated after COVID-19 vaccination. There was a significant WCC decrease (6.51 ± 1.49 vs 5.98 ± 1.65, p = 0.003) and CRP increase (0.40 ± 0.22 vs 0.50 ± 0.29, p = 0.004). CONCLUSION: This study found no imaging, biochemical or ECG evidence of myocardial injury or inflammation post COVID-19 vaccination, thus providing some reassurance that COVID-19 vaccinations do not typically cause subclinical myocarditis.

Long-term Effectiveness of Ethanol Ablation in Controlling Neck Nodal Metastases in Childhood Papillary Thyroid Cancer.

Context: Childhood papillary thyroid carcinoma (CPTC), despite bilateral thyroidectomy, nodal dissection and radioiodine remnant ablation (RRA), recurs within neck nodal metastases (NNM) in 33% within 20 postoperative years. These NNM are usually treated with reoperation or further radioiodine. Ethanol ablation (EA) may be considered when numbers of NNM are limited. Objective: We studied the long-term results of EA in 14 patients presenting with CPTC during 1978 to 2013 and having EA for NNM during 2000 to 2018. Methods: Cytologic diagnoses of 20 NNM (median diameter 9 mm; median volume 203 mm3) were biopsy proven. EA was performed during 2 outpatient sessions under local anesthesia; total volume injected ranged from 0.1 to 2.8 cc (median 0.7). All were followed regularly by sonography and underwent volume recalculation and intranodal Doppler flow measurements. Successful ablation required reduction both in NNM volume and vascularity. Results: Post EA, patients were followed for 5 to 20 years (median 16). There were no complications, including postprocedure hoarseness. All 20 NNM shrank (mean by 87%) and Doppler flow eliminated in 19 of 20. After EA, 11 NNM (55%) disappeared on sonography; 8 of 11 before 20 months. Nine ablated foci were still identifiable after a median of 147 months; only one identifiable 5-mm NNM retained flow. Median serum Tg post EA was 0.6 ng/mL. Only one patient had an increase in Tg attributed to lung metastases. Conclusion: EA of NNM in CPTC is effective and safe. Our results suggest that for CPTC patients who do not wish further surgery and are uncomfortable with active surveillance of NNM, EA represents a minimally invasive outpatient management option.

Radioiodine remnant ablation in stage I adult papillary thyroid carcinoma: does it improve postoperative outcome?

Objective: To determine whether radioiodine remnant ablation (RRA) reduces cause-specific mortality (CSM) or tumor recurrence rates (TRR) after potentially curative bilateral thyroidectomy (BT) in low-risk adult papillary thyroid carcinoma (APTC) patients, we compared postoperative outcomes in 1836 pTNM stage I APTC patients having BT alone with 832 having BT+RRA during two consecutive 25-year periods. Methods: The THEN cohort (consecutively managed during 1966-1990) comprised 809 patients (36% having BT+RRA) and the NOW cohort (1991-2015) comprised 1859 patients (29% BT+RRA). Analyses of differences in occurrence rates between BT alone and BT+RRA patients were performed with SAS software. Results: During 1966-1990, when RRA rates rose ten-fold, 20-year CSM after BT alone was 0.6% and after BT+RRA was 1.2% (P = 0.66); during 1991-2015, when RRA rates progressively fell, no PTC deaths occurred in 1859 patients. In the THEN cohort, RRA did not significantly improve TRR at local, regional, or distant sites (P > 0.1), when compared to BT alone. RRA in NOW cohort was administered to 49% of node-positive (pN1) patients and 17% of node-negative (pN0/NX) patients (P < 0.0001); TRR therefore, were examined separately for pN0/NX and pN1 patients. In 1157 pN0/NX cases, 20-year locoregional TRR were 3.1% after BT and were higher (P = 0.049) at 8.6% after BT+RRA. In four pN1 groups, stratified by metastatic nodal burden, RRA did not significantly reduce the locoregional TRR observed after BT with curative intent (P > 0.5). Conclusions: In a 5-decade experience, RRA administered postoperatively to stage I APTC patients did not reduce either CSM or TRR and should probably not be indicated when such patients undergo potentially curative BT.

Incidence of Clinically Relevant Thyroid Cancers Remains Stable for Almost a Century: A Population-Based Study.

OBJECTIVE: To examine the trends in incidence of clinically relevant thyroid cancers within the overall rising incidence of thyroid cancers. PATIENTS AND METHODS: This is a population-based cohort study conducted using the Rochester Epidemiology Project database to identify all new cases of thyroid cancer in Olmsted County, Minnesota, between January 1, 1935, and December 31, 2018. We extracted information about demographics and tumor pathologic type, size, and invasiveness. Clinically relevant cancers included aggressive histology or presence of metastatic disease, size larger than 4 cm, and gross extrathyroidal tumor invasion. RESULTS: Between 1935 and 2018, 596 thyroid cancer cases were diagnosed (mean age, 46.4 years; 72% female; 87% papillary cancers; and median tumor size, 1.5 cm). The sex- and age-adjusted incidence of thyroid cancer increased from 1.3 per 100,000 person-years (p-y) from 1935-1949 to 12.0 per 100,000 p-y in 2010-2018, corresponding to an absolute change per decade of 1.4 (95% CI, 0.7 to 2.2). There was a nonsignificant period absolute change for patients with tumor greater than 4 cm (0.03; 95% CI, -0.2 to 0.3), with evidence of tumor invasion (0.1; 95% CI, -0.1 to 0.4), and with aggressive histology or presence of metastatic disease (0.2; 95% CI, -0.1 to 0.6). Thyroid cancer mortality was unchanged over the observation period. CONCLUSION: Incidence rates of clinically relevant thyroid cancers, as defined by histology, size, and invasiveness, have not changed significantly in 80 years. The rising thyroid cancer incidence is driven by indolent thyroid cancers.

Inability of Radioiodine Remnant Ablation to Improve Postoperative Outcome in Adult Patients with Low-Risk Papillary Thyroid Carcinoma.

OBJECTIVE: To determine whether radioiodine remnant ablation (RRA) reduces cause-specific mortality (CSM) or tumor recurrence (TR) rate after bilateral lobar resection (BLR). PATIENTS AND METHODS: There were 2952 low-risk adult papillary thyroid cancer (LRAPTC) patients (with MACIS scores <6) who underwent potentially curative BLR during 1955-2014. During 1955-1974, 1975-1994, and 1995-2014, RRA was administered in 3%, 49%, and 28%. Statistical analyses were performed using SAS software. RESULTS: During 1955-1974, the 20-year CSM and TR rates after BLR alone were 1.0% and 6.8%; rates after BLR+RRA were 0% (P=.63) and 5.9% (P=.82). During 1975-1994, post-BLR 20-year rates for CSM and TR were 0.3% and 7.5%; after BLR+RRA, rates were higher at 0.9% (P=.31) and 12.8% (P=.01). When TR rates were examined separately for 448 node-negative and 317 node-positive patients, differences were nonsignificant. In 1995-2014, post-BLR 20-year CSM and TR rates were 0% and 9.2%; rates after BLR+RRA were higher at 1.4% (P=.19) and 21.0% (P<.001). In 890 pN0 cases, 15-year locoregional recurrence rates were 3.4% after BLR and 3.7% after BLR+RRA (P=.99). In 740 pN1 patients, 15-year locoregional recurrence rates were 10% higher after BLR+RRA compared with BLR alone (P=.01). However, this difference became nonsignificant when stratified by numbers of metastatic nodes. CONCLUSION: RRA administered to LRAPTC patients during 1955-2014 did not reduce either the CSM or TR rate. We would therefore not recommend RRA in LRAPTC patients undergoing BLR with curative intent.

Predicting Outcomes in Sporadic and Hereditary Medullary Thyroid Carcinoma over Two Decades.

Background: Medullary thyroid cancer (MTC) can be associated with significant morbidity and mortality in advanced cases. Hence, we aimed to identify factors at the time of MTC surgery that predict overall survival (OS), disease-specific survival (DSS), locoregional recurrence/persistence (LR), and distant metastases (DM). Methods: We performed a retrospective study of clinicopathologic, radiological, and laboratory data in MTC patients who underwent thyroidectomy at Mayo Clinic from January 1995 to December 2015. Results: We identified 163 patients (mean age 48.4 years, 48% males), 102 with sporadic MTC and 61 with hereditary disease (n = 46 multiple endocrine neoplasia [MEN] 2A, n = 3 MEN 2B, n = 12 familial MTC) with a median follow-up time of 5.5 years. On univariate analysis, age >55 years, male sex, DM at the time of surgery (M1), lateral neck lymph node (LN) involvement (N1b), gross extrathyroidal extension (ETE), American Joint Committee on Cancer (AJCC) stage 3/4, tumor size (T) 3/4, tumor size, and postoperative calcitonin (Ctn) and carcinoembryonic antigen (CEA) were significant predictors of worse OS and DSS. On multivariable analysis, both gross ETE (hazard ratio [HR] 4.62, 6.58) and M1 (HR 5.11, 10.45) remained significant predictors of worse OS as well as DSS, while age >55 years (HR 3.21), male sex (HR 2.42), and postoperative Ctn (HR 1.002 for every 100 pg/mL increase) were significant only for worse OS. On univariate analysis, male sex, M1, N1b, gross ETE, stage 3/4, T 3/4, tumor size, number of LNs involved, and postoperative Ctn were significant predictors of LR and DM; age >55 years was additionally significant for DM. On multivariable analysis, gross ETE (HR 3.16, 5.93) and N1b (HR 4.31, 4.64) remained significant predictors of LR and DM; ratio of resected/involved LN (HR 10.91) was additionally predictive for LR and postoperative Ctn (HR 1.003 for every 100 pg/mL increase) for DM. Conclusions: Disease burden at initial surgery, especially gross ETE, lateral neck LN involvement, and DM, as well as the biochemical response to surgery appear to be more important than demographic factors in terms of MTC prognosis. These findings highlight the importance of rigorous perioperative assessment to better predict MTC outcomes.

Long-Term Results of Treating With Ethanol Ablation 15 Adult Patients With cT1aN0 Papillary Thyroid Microcarcinoma.

BACKGROUND: Currently acceptable management options for patients with adult papillary thyroid microcarcinoma (APTM) range from immediate surgery, either unilateral lobectomy or bilateral lobar resection, to active surveillance (AS). An alternative minimally invasive approach, originally employed for eliminating neck nodal metastases, may be ultrasound-guided percutaneous ethanol ablation (EA). Here we present our experience of definitively treating with EA 15 patients with APTM. PATIENTS AND METHODS: During 2010 through 2017, the 15 cT1aN0M0 patients selected for EA were aged 36 to 86 years (median, 45 years). Tumor volumes (n = 17), assessed by sonography, ranged from 25 to 375 mm3 (median, 109 mm3). Fourteen of 15 patients had 2 ethanol injections on successive days; total volume injected ranged from 0.45 to 1.80 cc (median, 1.1 cc). All ablated patients were followed with sonography and underwent recalculation of tumor volume and reassessment of tumor perfusion at each follow-up visit. RESULTS: The ablated patients have now been followed for 10 to 100 months (median, 64 months). There were no complications and no ablated patient developed postprocedure recurrent laryngeal nerve dysfunction. All 17 ablated tumors shrank (median 93%) and Doppler flow eliminated. Median tumor volume reduction in 9 identifiable avascular foci was 82% (range, 26%-93%). After EA, 8 tumors (47%) disappeared on sonography after a median of 10 months. During follow-up no new PTM foci and no nodal metastases have been identified. CONCLUSIONS: Definitive treatment of APTM by EA is effective, safe, and inexpensive. Our results suggest that, for APTM patients who do not wish neck surgery and are uncomfortable with AS, EA represents a well-tolerated and minimally invasive outpatient management option.

Elimination of Locoregional Recurrences and Skin Metastases in Papillary Thyroid Cancer by Ethanol Ablation and Mohs Surgery.

Ultrasound-guided percutaneous ethanol ablation procedures for locoregional recurrences in papillary thyroid carcinoma (PTC) can be repeatedly performed over years. Skin metastases (SM) from PTC generally portend a lethal prognosis. Our patient case report demonstrates the innovative use in low-risk PTC (LRPTC) of treatment modalities designed to prevent neck re-explorations and capable of eliminating both locoregional recurrences and SM. In 2004, a 48-year-old man presented with neck nodal metastases due to PTC. He underwent a near-total thyroidectomy and nodal dissection, confirming an 8-mm PTC involving 2 ipsilateral node metastases. Postoperatively, he received 2 doses of radioactive iodine (RAI) for remnant uptake (cumulative dose 338 mCi); posttherapy scanning was unrevealing. In 2007, he underwent right neck dissection for further node metastases. In 2008, a guided biopsy confirmed a level IV node metastasis. He was referred to our institution for ethanol ablation. Two node metastases were ablated and subsequently disappeared. During 2010-2016, he developed an additional 6 node metastases, which were treated with ethanol ablation; all disappeared on high-resolution sonography. FDG-PET-CT scans in 2009 and 2016 were negative for distant spread. In 2016, a SM in his right neck was removed by dermatologic surgery. In 2017-2018, 2 further SM were excised with negative margins, one after Mohs surgery. He has now been disease-free for 20 months. In conclusion, despite 3 neck surgeries and 2 RAI therapies, our patient repeatedly developed both locoregional recurrences and SM. All 11 disease foci were eliminated with minimally invasive procedures which should more often be considered as effective treatment options in LRPTC.

Mild-to-Moderate Gestational Iodine Deficiency Processing Disorder.

This synopsis paper aims to identify if a common pattern of learning and social difficulties can be conceptualized across recent longitudinal studies investigating the influence of mild-to-moderate gestational iodine deficiency (GID) on offspring's optimal cognitive and psycho-social development. The main studies investigated are: The Southampton Women's Study (SWS)-United Kingdom; the Avon Longitudinal Study of Parents and Children (ALSPAC)-United Kingdom; the Gestational Iodine Cohort Longitudinal Study-Tasmania, Australia, and the Danish National Birth Cohort Case-Control Study-Denmark. In contrast to severe GID where there is a global negative impact on neurodevelopment, mild-to-moderate intrauterine iodine deficiency has subtler, but nonetheless important, permanent cognitive and psycho-social consequences on the offspring. This paper links the results from each study and maintains that mild-to-moderate GID is associated with a disorder that is characterized by speed of neural transmitting difficulties that are typically associated with working memory capacity difficulties and attention and response inhibition. The authors maintain that this disorder is better identified as Gestational Iodine Deficiency Processing Disorder (GIDPD), rather than, what to date has often been identified as 'suboptimal development'. The Autistic Spectrum Disorder (ASD), Attention Deficit, Hyperactivity Disorder (ADHD), language and literacy disorders (learning disabilities and dyslexia) are the main manifestations associated with GIDPD. GIDPD is identified on IQ measures, but selectively and mainly on verbal reasoning IQ subtests, with individuals with GIDPD still operating within the 'normal' full-scale IQ range. Greater consideration needs to be given by public health professionals, policy makers and educators about the important and preventable consequences of GID. Specifically, more emphasis should be placed on adequate iodine intake in women prior to pregnancy, as well as during pregnancy and when lactating. Secondly, researchers and others need to further extend, refine and clarify whether GIDPD, as a nosological (medical classification) entity, is a valid disorder and concept for consideration.

Correction: Hynes et al. "Reduced Educational Outcomes Persist into Adolescence Following Mild Iodine Deficiency in Utero, Despite Adequacy in Childhood: 15-Year Follow-Up of the Gestational Iodine Cohort Investigating Auditory Processing Speed and Working Memory" Nutrients 2017, 9 (12), 1354.

The authors wish to make a correction to the published version of their paper [...].

Management of Papillary Thyroid Microcarcinoma.

The worldwide incidence of thyroid cancer is increasing. A third of new thyroid cancer cases are papillary thyroid microcarcinoma (PTM), which are 1 cm or less. These tumors are mostly indolent with excellent prognosis. Although thyroid surgery is the most common management option for patients with PTM, new management options demand that treatment decisions must be individualized and based on patient's preference, context, and biology. This article describes management options for PTM patients and shared decision-making as a novel method for individualizing care.

Papillary Thyroid Carcinoma (PTC) in Children and Adults: Comparison of Initial Presentation and Long-Term Postoperative Outcome in 4432 Patients Consecutively Treated at the Mayo Clinic During Eight Decades (1936-2015).

BACKGROUND: Contemporary guidelines for managing PTC advise an approach wherein primary tumor and regional metastases (RM) are completely resected at first surgery and radioiodine remnant ablation (RRA) is restricted to high-risk patients, policies our group has long endorsed. To assess our therapeutic efficacy, we studied 190 children and 4242 adults consecutively treated during 1936-2015. SUBJECTS AND METHODS: Mean follow-up durations for children and adults were 26.9 and 15.2 years, respectively. Bilateral lobar resection was performed in 86% of children and 88% of adults, followed by RRA in 30% of children and 29% of adults; neck nodes were excised in 86% of children and 66% of adults. Tumor recurrence (TR) and cause-specific mortality (CSM) details were taken from a computerized database. RESULTS: Children, when compared to adults, had larger primary tumors which more often were grossly invasive and incompletely resected. At presentation, children, as compared to adults, had more RM and distant metastases (DM). Thirty-year TR rates were no different in children than adults at any site. Thirty-year CSM rates were lower in children than adults (1.1 vs. 4.9%; p = 0.01). Comparing 1936-1975 (THEN) with 1976-2015 (NOW), 30-year CSM rates were similar in MACIS <6 children (p = 0.67) and adults (p = 0.08). However, MACIS <6 children and adults in 1976-2015 had significantly higher recurrence at local and regional, but not at distant, sites. MACIS 6+ adults, NOW, compared to THEN, had lower 30-year CSM rates (30 vs. 47%; p < 0.001), unassociated with decreased TR at any site. CONCLUSIONS: Children, despite presenting with more extensive PTC when compared to adults, have postoperative recurrences at similar frequency, typically coexist with DM and die of PTC less often. Since 1976, both children and adults with MACIS <6 PTC have a <1% chance at 30 years of CSM; adults with higher MACIS scores (6 or more) have a 30-year CSM rate of 30%.

Reduced Educational Outcomes Persist into Adolescence Following Mild Iodine Deficiency in Utero, Despite Adequacy in Childhood: 15-Year Follow-Up of the Gestational Iodine Cohort Investigating Auditory Processing Speed and Working Memory.

There is increasing evidence that even mild gestational iodine deficiency (GID) results in adverse neurocognitive impacts on offspring. It's unclear, however, if these persist long-term and whether they can be ameliorated by iodine sufficiency in childhood. We followed a unique cohort (Gestational Iodine Cohort, n = 266) where gestation occurred during a period of mild population iodine deficiency, with children subsequently growing-up in an iodine replete environment. We investigated whether associations between mild GID and reductions in literacy outcomes, observed at age 9-years, persisted into adolescence. Comparisons were made between offspring of mothers with gestational urinary iodine concentrations (UICs) ≥ 150 µg/L and < 150 µg/L. Educational outcomes were measured using Australian National Assessment Program-Literacy and Numeracy (NAPLAN) tests. Children whose mothers had UICs < 150 µg/L exhibited persistent reductions in spelling from Year 3 (10%, -41.4 points (95% Confidence Interval -65.1 to -17.6, p = 0.001)) to Year 9 (5.6%, -31.6 (-57.0 to -6.2, p = 0.015)) compared to children whose mothers had UICs ≥ 150 µg/L. Associations remained after adjustment for biological factors, socioeconomic status and adolescent UIC. Results support the hypothesis that mild GID may impact working memory and auditory processing speed. The findings have important public health implications for management of iodine nutrition in pregnancy.

Survival in Response to Multimodal Therapy in Anaplastic Thyroid Cancer.

Context: Historical outcomes in anaplastic thyroid cancer (ATC) have been dismal. Objective: To determine whether an initial intensive multimodal therapy (MMT) is associated with improved ATC survival. Design: MMT was offered to all patients with newly diagnosed ATC treated at the Mayo Clinic from 2003 through 2015; MMT vs care with palliative intent (PI) was individualized considering clinical status and patient preferences. Outcomes were retrospectively analyzed by American Joint Committee on Cancer stage and treatments compared with patient cohort data from 1949 through 1999. Patients: Forty-eight patients (60% male; median age, 62 years); 18 treated with PI, 30 with MMT. Main Outcome Measure: Overall survival (OS) and progression-free survival determined by Kaplan-Meier method. Results: Median OS and 1-year survival for the later cohort were 9 months [95% confidence interval (CI), 4 to 22 months] and 42% (95% CI, 28% to 56%) vs 3 months and 10% for the earlier cohort. Median OS was 21 months compared with 3.9 months in the pooled MMT vs PI groups for the later cohort [hazard ratio (HR), 0.32; P = 0.0006]. Among only patients in the later cohort who had stage IVB disease, median OS was 22.4 vs 4 months (HR, 0.12; 95% CI, 0.03 to 0.44; P = 0.0001), with 68% vs 0% alive at 1 year (MMT vs PI). Among patients with stage IVC cancer, OS did not differ by therapy. Conclusion: MMT appears to convey longer survival in ATC among patients with stage IVA/B disease.

Minimal extrathyroid extension in papillary thyroid carcinoma does not result in increased rates of either cause-specific mortality or postoperative tumor recurrence.

BACKGROUND: This study assessed the influence of extrathyroid extension (EE) on cause-specific mortality (CSM) and tumor recurrence (TR) in patients treated for papillary thyroid carcinoma (PTC). METHODS: We studied outcome in 3,524 patients with PTC without distant metastases at diagnosis. CSM and TR were investigated in 422 patients with gross EE (GEE) or microscopic EE (MEE). RESULTS: The 30-year CSM rate for GEE of 25% was 12-fold greater (P < .001) than 2% seen with surgically intra-thyroid tumors (SIT); no patient who underwent MEE died of PTC. No difference (P = .36) existed in CSM rates between 127 MEE and 3,102 microscopically intra-thyroid tumors (MITs). The 20-year TR rate for GEE was 43% versus 12% with SIT (P < .001). Analyzing only 2,067 pN0 tumors, we found that GEE patients had greater TR rates (all sites), compared with SIT or MEE (P < .001). When 44 MEE were compared with 1,941 MIT cases, TR (all sites) rates were not different (P = .74). In patients aged >45 with tumors <41 mm, 20-year TR rates for MIT (stages I/II) and MEE (stage III) were not different at 4.7% and 3.8% (P = .71). CONCLUSION: MEE without concomitant GEE did not increase rates of either CSM or TR in PTC. Accordingly, these results raise concerns regarding current AJCC staging recommendations.

The Impact of Subclinical Disease and Mechanism of Detection on the Rise in Thyroid Cancer Incidence: A Population-Based Study in Olmsted County, Minnesota During 1935 Through 2012.

BACKGROUND: An ongoing epidemic of thyroid carcinoma (TC) has affected Americans since 1975. Understanding the contribution of subclinical disease and the mechanism of such disease detection may help to alter the course of this epidemic. METHODS: We used Rochester Epidemiology Project resources to examine the incidence of TC cases, disease specific mortality, and method of diagnosis during 1935 through 2012. During 2000-2012, we also extracted the mechanism of detection of clinically occult tumors. RESULTS: The age-adjusted incidence (AAI) for TC increased from 7.1 [95% confidence interval (CI) 5.5-8.8] per 100,000 person-years (p-y) during 1990-1999 to 13.7 [CI 11.8-15.6] per 100,000 p-y during 2000-2012, with no change in disease-specific mortality since 1935. The incidence trend analysis stratified by the mechanism of detection revealed the AAI of clinically recognized TC was 5.5 per 100,000 p-y [CI 3.4-7.5] in 1960-1969, a rate similar to the incidence seen during 2000-2012. However, AAI of clinically occult TC increased from 0.2 per 100,000 p-y [CI 0.0-0.6] in 1935-1949 to 1.9 per 100,000 p-y [CI 1.2-2.9] in 1990-1999 and to 7.4 per 100,000 p-y [CI 6.0-8.8] in 2000-2012. During 2000-2012, the most frequent reasons for recognition of "occult" tumors were (1) incidental discovery during diagnostic neck imaging in 40 (19%), (2) pathology review of specimens from thyroid surgery for benign conditions in 29 (14%), and (3) investigations of patients with symptoms or palpable nodules that were clearly not associated with coexistent but occult TC but triggered the use of diagnostic neck imaging in 37 (27%). CONCLUSIONS: In this population-based study conducted in Olmsted County, Minnesota, the rapid increased incidence of TC during 2000-2012 can be completely attributed to the increased diagnosis of occult TCs, which are mainly found through the use of diagnostic neck imaging. The incidence of clinical TC and disease-specific TC mortality remains stable since 1970, implying that the observed increased incidence is due to the increased detection of subclinical lesions.