Analysis of thyroid carcinoma based on material registered in Japan during 1977-1986 with special reference to predominance of papillary type

Demographic, clinical, and surgical features of patients undergoing thyroidectomy due to thyroid lesions in Southern Iran: A cross-sectional study

Background and Aims

The incidence of thyroid cancer has witnessed a significant global increase and stands as one of the most prevalent cancers in Iran. This surge is primarily attributed to the escalating incidence of papillary thyroid cancer (PTC), with overdiagnosis emerging as an equally noteworthy factor. Consequently, this study aims to ascertain the incidence of thyroid cancer, along with its clinical presentation, demographic characteristics, and surgical features in patients undergoing thyroid surgery.

Methods

This cross-sectional study involved the evaluation of patient files from referral centers in Shiraz spanning the years 2015-2020. Demographic and clinical information pertaining to thyroid cancer was extracted and subsequently analyzed using SPSS software.

Results

A total of 533 documented cases of thyroid cancer undergoing surgery revealed an annual rate of 89 cases in our location. The average age of the patients was 43.9 ± 13.4 years (ranging from 13 to 92), with females constituting 429 (83.5%) of the cases, and 278 (54.1%) being malignant. Conventional PTC emerged as the most prevalent pathology, accounting for 239 (45.0%) of the cases. Patients with thyromegaly exhibited significantly higher incidences of nonmalignant tumors (p = 0.01), while those with malignant tumors were notably younger than those with nonmalignant tumors (p = 0.001).

Conclusion

Our study revealed a progressive rise in the number of patients undergoing thyroidectomy over the years, with PTC constituting the majority of cases. Malignant cases were more frequently observed in younger patients, and in smaller lesion sizes, highlighting the importance of early screening and optimizing detection methods, especially in high-risk populations.

Multikinase Inhibitor Treatment Patterns for Advanced Thyroid Cancer in Japan: An Administrative Claims Database Study

BACKGROUND

The multikinase inhibitors (MKIs) sorafenib, lenvatinib, and vandetanib are approved for advanced thyroid cancer (TC) in Japan. How sequential treatment with MKIs is conducted in Japanese clinical practice is unknown.

METHODS

This retrospective observational cohort study used a Japanese administrative claims database (April 2008-September 2021). Patients with a confirmed TC subtype diagnosis of papillary (PTC), follicular (FTC), medullary (MTC), or anaplastic (ATC), who received MKI treatment after TC diagnosis within the index period (June 2014-August 2021), were included. Overall MKI treatment duration was estimated by Kaplan-Meier analysis.

RESULTS

The analysis population included 795 patients (PTC, N = 447; FTC, N = 86; MTC, N = 32; ATC, N = 230). Median age was ≥ 64 years; most patients (> 60%) were female except for the MTC subgroup (43.8%). First-line (1L) MKI treatment was mainly lenvatinib for PTC (81.7%), FTC (83.7%), and ATC (97.8%), and vandetanib for MTC (62.5%). Among patients discontinuing 1L MKI treatment and evaluable for subsequent therapy [PTC: 57.9% (259/447); FTC: 48.8% (42/86); MTC: 62.5% (20/32); ATC: 70.4% (162/230)], 26.3% (68/259), 21.4% (9/42), 50.0% (10/20), and 4.9% (8/162) of PTC, FTC, MTC, and ATC patients, respectively, received second-line (2L) treatment. Median (95% CI) overall MKI treatment duration was 21.2 (17.9-27.5), 43.9 (30.9-not assessable), 39.0 (17.7-not assessable), and 4.0 (3.0-4.8) months for PTC, FTC, MTC, and ATC, respectively.

CONCLUSION

Advanced TC treatment options are limited. In this study, most patients received only 1L MKI treatment; of those who discontinued 1L, ≤ 50% progressed to 2L.

Predictive value of calcium test for preoperative diagnosis of medullary thyroid carcinoma in patients with moderately elevated basal calcitonin

INTRODUCTION

Medullary thyroid carcinoma (MTC) can be very aggressive, and the early diagnosis is based on the routine measurement of serum calcitonin (CT) and on the RET genetic testing for hereditary forms. Basal serum CT concentrations (bCT) are helpful in the early detection of MTC, while it is still unclear whether they can be used also for the differential diagnosis between MTC and C cell hyperplasia (CCH). Since false-positive results can be gained with the basal measurement of calcitonin, a provocative test to evaluate stimulated calcitonin (sCT) is often needed.

AIM

The objective of this study was to investigate the utility of calcium gluconate test for CT in distinguishing MTC from CCH, a precancerous condition in hereditary forms of MTCs, but with unclear significance in sporadic MTCs.

METHOD

A total of 74 patients underwent the calcium loading test before thyroidectomy, and basal and stimulated calcitonin levels were compared with histological results by receiver operating characteristic (ROC) plot analyses.

RESULTS

A peak of calcitonin after stimulation with calcium gluconate of 388.4 pg/ml was able to significantly distinguish patients with MTC from patients with CCH and patients without C cell pathology, with 81.8% sensitivity and 36.5% specificity. Basal calcitonin of 16.1 pg/ml was able to distinguish these two group of patients with 90% sensitivity.

CONCLUSION

High dose calcium test is potent procedure that can be applied for differential diagnosis of MTC and CCH. Reference ranges for calcium sCT levels and CT thresholds in different group of patients have been identified.

Pyruvate carboxylase promotes thyroid cancer aggressiveness through fatty acid synthesis

Background

Pyruvate carboxylase (PC) is an important anaplerotic enzyme in the tricarboxylic acid cycle (TCA) in cancer cells. Although PC overexpression has been observed in thyroid cancer (TC), the mechanisms involved in the carcinogenic effects of PC are still unclear.

Methods

Bioinformatics analysis and clinical specimens were used to analyze the relationship of PC expression with clinicopathological variables in TC. Fatty acid synthesis was monitored by LC/MS, Nile red staining, and triglyceride analysis. Mitochondrial oxygen consumption was evaluated by the Seahorse XF Mito Cell Stress Test. The correlation of PC with FASN and SREBP1c was assessed by qRT-PCR and IHC in 38 human TC tissues. Western blotting was used to evaluate the protein expression of PC, FASN, and SREBP1c and members of the AKT/mTOR and EMT pathways in TC cell lines. Wound-healing, CCK-8, and Transwell assays and a nude mouse xenograft model were used to verify the regulatory effects of PC and SREBP1c on thyroid tumor cell proliferation, migration and invasion.

Results

We demonstrated that PC increased fatty acid synthesis, which then promoted TC progression and metastasis. Analysis of GEO data showed that the overexpression of PC in papillary thyroid cancer (PTC) was associated with PTC invasion and the fatty acid synthesis pathway. Analysis of clinical tissue specimens from PTC patients revealed that PC was more highly expressed in specimens from PTC patients with lymph node metastasis than in those from patients without metastasis. Multiple genes in the fatty acid synthesis signaling pathway, including FASN and SREBP1c, were downregulated in PC-knockdown TC cells compared to control cells. Lipid levels were also decreased in the PC-knockdown TC cells. Moreover, the ability of cells to grow, invade, and metastasize was also suppressed upon PC knockdown, suggesting that PC-mediated lipogenesis activation increases the aggressiveness of TC cells. In addition, PC was found to activate the AKT/mTOR pathway, thus improving FASN-mediated de novo lipogenesis in TC cells by upregulating SREBP1c expression. Studies in a nude mouse xenograft model showed that PC knockdown decreased tumor weight, but this effect was attenuated by forced expression of SREBP1c.

Conclusions

Our results demonstrate that PC is strongly involved in the tumor aggressiveness of TC via its stimulation of fatty acid synthesis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08499-9.

Neutrophil-to-Lymphocyte Ratio as a Prognostic Marker for Anaplastic Thyroid Cancer Treated With Lenvatinib

BACKGROUND/AIM

Lenvatinib is one of the few options for patients with anaplastic thyroid cancer (ATC). However, tumor markers for ATC treated with lenvatinib is lacking. The aim of this study was to explore whether the neutrophil-to-lymphocyte ratio (NLR) can be a tumor marker for ATC treated with lenvatinib.

PATIENTS AND METHODS

We retrospectively analyzed the prognostic significance of the NLR in 13 ATC patients treated with lenvatinib.

RESULTS

The disease control rate was better in patients with lower NLR (<8; 89%) than higher NLR (≥8; 25%) (p=0.05). Median progression-free survival and overall survival were longer in patients with lower NLR than higher NLR (4.0 vs. 1.6 months, p<0.05; and 10.2 vs. 3.8 months, p<0.05, respectively). Patients whose NLR on day 14 decreased compared to baseline had a slightly higher overall response rate than patients without NLR decrease (42.9% vs. 0%, p=0.19).

CONCLUSION

The baseline NLR is a potential prognostic marker, and the change of NLR can be an early indicator of response for ATC patients treated with lenvatinib.

Synergy of GSK-J4 With Doxorubicin in KRAS-Mutant Anaplastic Thyroid Cancer

Background

Anaplastic thyroid cancer is the most aggressive thyroid cancer and has a poor prognosis. At present, there is no effective treatment for it.

Methods

Here, we used different concentrations of GSK-J4 or a combination of GSK-J4 and doxorubicin to treat human Cal-62, 8505C, and 8305C anaplastic thyroid cancer (ATC) cell lines. The in vitro experiments were performed using cell viability assays, cell cycle assays, annexin-V/PI binding assays, Transwell migration assays, and wound-healing assays. Tumor xenograft models were used to observe effects in vivo.

Results

The half maximal inhibitory concentration (IC50) of GSK-J4 in Cal-62 cells was 1.502 μM, and as the dose of GSK-J4 increased, more ATC cells were blocked in the G2-M and S stage. The combination of GSK-J4 and doxorubicin significantly increased the inhibitory effect on proliferation, especially in KRAS-mutant ATC cells in vivo (inhibition rate 38.0%) and in vitro (suppresses rate Fa value 0.624, CI value 0.673). The invasion and migration abilities of the KRAS-mutant cell line were inhibited at a low concentration (p < 0.05).

Conclusions

The combination of GSK-J4 with doxorubicin in KRAS-mutant ATC achieved tumor-suppressive effects at a low dose. The synergy of the combination of GSK-J4 and doxorubicin may make it an effective chemotherapy regimen for KRAS-mutant ATC.

Analysis of Malignant Thyroid Neoplasms with a Striking Rise of Papillary Microcarcinoma in an Endemic Goiter Region

According to National Cancer Registry Program, Thiruvananthapuram district of Kerala, has the highest relative frequency of thyroid carcinomas; nevertheless, limited data exist regarding its socio-demographic and clinico-pathological characteristics. The aims of the study were to assess the: (1) demographic characteristics, (2) histopathological features and the relative frequency of various thyroid carcinoma cases and papillary thyroid carcinoma (PTC) subtypes, (3) rising trend of papillary microcarcinomas, and (4) associated lesions. A retrospective study wherein 170 cases of thyroid malignancies reported in our single institution over a period of 8 years period was reviewed. PTC accounted for 97% cases, followed by medullary (n = 4; 2.4%) and follicular carcinoma (n = 1; 0.6%). There was female preponderance (p = 0.0379) with a lower median age in females (p = 0.0275). Among the PTCs, conventional type constituted 53.4% cases (n = 87), followed by microcarcinomas (n = 34; 20.9%), follicular variant (n = 28; 17.2%), and others 14 cases (8.5%). Thirty-three cases (19.4%) showed multifocality, 5 cases (2.9%) extra-thyroid extension, and 19 cases (11.2%) lymph node metastasis. Two cases developed recurrences and three cases, metastasis. The associated lesions were significantly higher in females (p = 0.0059); most common being multinodular goiter (MNG; n = 67; 41.1%), followed by Hashimoto thyroiditis (n = 44; 27%) and lymphocytic thyroiditis (n = 28; 17.2%); MNG being associated with follicular (p = 0.0129), and Hashimoto thyroiditis with conventional variant (p = 0.0475). The frequency of microcarcinomas significantly increased in the past 4 years (p = 0.0291) and was associated with MNG (p = 0.0055), Hurthle cell nodule (p = 0.0315) and absent lymph node metastasis (p = 0.0147). The primary treatment modality was total thyroidectomy. Papillary microcarcinoma cases increased significantly in the past 4 years and were significantly associated with MNG and Hurthle cell nodule. It is challenging to distinguish the various PTC subtypes as recognition of these histological variants warrants better patient management.

Static Prognostic Factors and Appropriate Surgical Designs for Patients with Medullary Thyroid Carcinoma: The Second Report from a Single-Institution Study in Japan

Background

Medullary thyroid carcinoma (MTC) originates from calcitonin-producing cells of the thyroid. In 2009, we published our first report on the biological characteristics and prognosis of 118 MTC patients. Herein, we enrolled a larger number of patients with longer follow-up periods to further study the biological characteristics and appropriate therapies for MTC.

Methods

In general, hemithyroidectomy and total thyroidectomy were performed for sporadic MTC confined to the thyroid lobe and for hereditary MTC with central node dissection, respectively. Moreover, prophylactic modified radical neck dissection was performed on the side of macroscopic tumors.

Results

In total, 233 patients (99 hereditary and 134 sporadic) were enrolled. The median follow-up time was 128 months (range 7–445 months). Biochemical cure was obtained in 36 (62%) of the 58 patients who underwent prophylactic MND and were pathologically positive for lateral node metastasis. None of the patients had recurrence in the preserved thyroid. Distant recurrence was detected in 19 patients, and 12 died of MTC. Preoperative calcitonin and carcinoembryonic antigen levels, tumor size (T) > 4 cm, the male sex, clinical and pathological node metastases (N1), distant metastasis (M1), extrathyroid extension (Ex), and a lack of biochemical cure had prognostic impacts on distant recurrence and/or carcinoma-related mortality on univariate analysis. On multivariate analysis, Ex was independently correlated with distant recurrence, and Ex, T > 4 cm, and M1 independently affected carcinoma-related mortality.

Conclusion

MTC patients had excellent prognosis in our institutions, indicating that our surgical strategies were appropriate.

Thyroid Cancer in Children and Adolescents

Aims and background

It was the aim of this paper to report clinical and pathologic characteristics and outcome of treatment in terms of relapse-free and overall survival in 36 patients under 20 years of age and treated for thyroid cancer at Padua University Hospital from January 1968 to December 1988 and followed until December 1992.

Methods

The median follow-up was 112 months (range 3 to 228 months). Age at diagnosis ranged from 4 to 20 years with a mean age of 15 years and a male/female ratio of 1:2.9. A thyroid nodule or a laterocervical mass was the most frequent sign of presentation. The routine diagnosis schedule included thyroid scintigram, neck echotomography and in the last decade fine needle aspiration biopsy.

Results

Sixteen (28%) patients had a family history of thyroid disease. Histology revealed that papillary carcinoma was present in 43 patients (76.8%), follicular carcinoma in 9 (16%), medullary carcinoma in 2 (3.6%) and lymphoma in 2 (3.6%). Fifty-four patients were treated with total thyroidectomy, of these 34 had bilateral neck dissection and 20 unilateral nodal dissection; 2 patients underwent simple lobectomy with unilateral dissection. Nodal involvement was present in 41 (73%) cases, and synchronous visceral metastases were detected with scan and/or chest X-ray in 10 (18%) cases. In the case of differentiated thyroid carcinoma, patients with residual disease or thyroid remnants were treated with 131I metabolic therapy. All patients were put on suppressive hormone therapy. At this writing, 52 (93%) patients were in complete remission and 4 (7%) had persistent disease. Recurrences developed in 2 (3.5%) patients: one presented lung metachronus metastases and one local recurrence; no deaths have occurred.

Conclusions

From this experience, total thyroidectomy appears to be the appropriate approach for differentiated tumors in children and adolescents because the disease is often diffuse, secondary deposits may be easily detected, and the value of thyroglobulin measurement can be improved. Following this strategy, overall recurrence risk was low and 131I therapy was curative in patients with nodal and lung metastases.

The Clinical Relevance of Psammoma Body and Hashimoto Thyroiditis in Papillary Thyroid Carcinoma: A Large Case-control Study

This study aims to investigate the impact of psammoma body (PB) on papillary thyroid carcinoma (PTC), and evaluate the association among PB, Hashimoto thyroiditis (HT), and other clinicopathologic characteristics in PTC patients.We conducted a retrospective case-control study involving 1052 PTC patients who underwent total thyroidectomy or lobectomy with lymph node dissection.Psammoma body was observed in 324 out of 1052 PTC (30.8%) patients. Ultrasonographic (US) calcification (P < 0.001), multifocality of the tumor (P = 0.047), lymph node metastasis (LNM) (P < 0.001), HT (P < 0.001), and Primary tumor (T), Regional lymph nodes (N), Distant metastasis (M) staging (P = 0.001) were significantly related to the presence of PB. The presence of PB was significantly associated with US microcalcification (P < 0.001). In the subgroup with HT, compared with the patients without PB, the patients with PB exhibited a higher frequency of central LNM (54.7% vs 32.1%; P < 0.001) and US microcalcification (94.7% vs 38.8%; P < 0.001), as well as smaller tumors (0.9 ± 0.6 vs 1.3 ± 0.9 cm; P < 0.001). In the subgroup without HT, the patients with PB displayed a higher incidence of lateral LNM (25.8% vs 14.6%; P < 0.001), US microcalcification (87.3% vs 52.5%; P < 0.001), and extrathyroidal extension (47.2% vs 34.8%; P = 0.001), as well as larger tumors (1.3 ± 0.9 vs 1.0 ± 0.8 cm; P < 0.001) than without PB. Moreover, in the subgroup with PB, the PTC patients with HT showed a higher LNM (77.9% vs 57.2%; P < 0.001) and a lower frequency of extrathyroidal extension (20.0% vs 47.2%; P < 0.001) than without HT.Psammoma body is a useful predictor of aggressive tumor behavior in PTC patients. HT with PB shows more aggressive behaviors than non-HT with PB in PTC patients.

B-RafV600E inhibits sodium iodide symporter expression via regulation of DNA methyltransferase 1

B-RafV600E mutant is found in 40-70% of papillary thyroid carcinoma (PTC) and has an important role in the pathogenesis of PTC. The sodium iodide symporter (NIS) is an integral plasma membrane glycoprotein that mediates active iodide transport into the thyroid follicular cells, and B-RafV600E has been known to be associated with the loss of NIS expression. In this study, we found that B-RafV600E inhibited NIS expression by the upregulation of its promoter methylation, and that specific regions of CpG islands of NIS promoter in B-RafV600E harboring PTC were highly methylated compared with surrounding normal tissue. Although DNA methyltransferase 3a and 3b (DNMT3a,3b) were not increased by B-RafV600E, DNMT1 expression was markedly upregulated in PTC and B-RafV600E expressing thyrocytes. Furthermore, DNMT1 expression was upregulated by B-RafV600E induced NF-κB activation. These results led us to conclude that NIS promoter methylation, which was induced by B-RafV600E, is one of the possible mechanisms involved in NIS downregulation in PTC.

Clinical outcome after bone metastasis (BM) surgery in patients with differentiated thyroid carcinoma (DTC): a retrospective study of 40 cases

OBJECTIVE

The purpose of this study is to identify factors that affect survival of patients with differentiated thyroid carcinoma with bone metastases and to optimize surgical treatment modality for bone metastatic lesion by comparing duration of patient survival and local control.

METHODS

We examined 52 bone metastatic lesions from 40 patients with differentiated thyroid carcinoma who were treated surgically between 1994 and 2008 at Keio University Hospital. Median follow-up time was 46 months (range: 4-233 months). Patients' disease-specific survival, local control duration and factors that potentially affected disease-specific survival after bone metastasis surgery were statistically analyzed.

RESULTS

The 2-, 5- and 10-year disease-specific survival rates were 77.2, 64.3 and 45.7%, respectively. Factors that were significantly associated with poor survival rates in multivariate analyses included age at bone metastasis surgery ≥65 years (P = 0.0068), time from diagnosis of primary cancer to bone metastasis surgery ≥5 years (P = 0.0018) and presence of visceral metastases (P = 0.0092). The 2-, 5- and 10-year local control rates in our series were 91.4, 72.7 and 63.6%, respectively. The 5-year local control rates for radical and palliative surgery were 84.4 and 55.3%, respectively, and differed significantly (P = 0.019).

CONCLUSIONS

Because disease-specific survival of patients with differentiated thyroid carcinoma is fairly good, inadequate treatment of bone metastatic lesions can result in severe disabilities. Therefore, radical surgery for bone metastatic lesions should be considered, especially for those with favorable prognostic factors.

A newly identified missense mutation in RET codon 666 is associated with the development of medullary thyroid carcinoma

A 38-year-old woman with a thyroid nodule measuring approximately 2 cm was suspected to have medullary thyroid carcinoma (MTC) because of markedly elevated serum calcitonin and carcinoembryonic antigen levels. There were no signs of pheochromocytoma, whereas primary hyperparathyroidism was suspected based on the findings of inappropriate hypersecretion of parathyroid hormone although no parathyroid tumor was detected with imaging studies. RET mutation analysis revealed a novel germline missense mutation in codon 666, c.1997A>G (p.K666R). She underwent total thyroidectomy with lymphadenectomy and simultaneous total parathyroidectomy with autotransplantation of parathyroid tissue. She was given calcium lactate and alfacalcidol to prevent postoperative hypocalcemia. Pathological findings of the thyroid tumor were compatible with MTC, but the resected parathyroid glands were intact. To our knowledge, c.1997A>G (p.K666R) is a new RET mutation. This is a minor variant, but it is significant because of the possible pathogenicity in tumor formation. It is often difficult to determine whether MTC is generated as part of MEN2-related disease or familial MTC when it is a unique manifestation. In addition, it is still unclear whether all missense mutations in this codon reported previously will lead to the same clinical course and prognosis. Further careful observations of clinical presentation are required to determine the clinical features associated with this variant.

Spatial autocorrelation of cancer incidence in Saudi Arabia

Little is known about the geographic distribution of common cancers in Saudi Arabia. We explored the spatial incidence patterns of common cancers in Saudi Arabia using spatial autocorrelation analyses, employing the global Moran's I and Anselin's local Moran's I statistics to detect nonrandom incidence patterns. Global ordinary least squares (OLS) regression and local geographically-weighted regression (GWR) were applied to examine the spatial correlation of cancer incidences at the city level. Population-based records of cancers diagnosed between 1998 and 2004 were used. Male lung cancer and female breast cancer exhibited positive statistically significant global Moran's I index values, indicating a tendency toward clustering. The Anselin's local Moran's I analyses revealed small significant clusters of lung cancer, prostate cancer and Hodgkin's disease among males in the Eastern region and significant clusters of thyroid cancers in females in the Eastern and Riyadh regions. Additionally, both regression methods found significant associations among various cancers. For example, OLS and GWR revealed significant spatial associations among NHL, leukemia and Hodgkin's disease (r² = 0.49-0.67 using OLS and r² = 0.52-0.68 using GWR) and between breast and prostate cancer (r² = 0.53 OLS and 0.57 GWR) in Saudi Arabian cities. These findings may help to generate etiologic hypotheses of cancer causation and identify spatial anomalies in cancer incidence in Saudi Arabia. Our findings should stimulate further research on the possible causes underlying these clusters and associations.

Aberrantly methylated genes in human papillary thyroid cancer and their association with BRAF/RAS mutation

Cancer arises through accumulation of epigenetic and genetic alteration. Aberrant promoter methylation is a common epigenetic mechanism of gene silencing in cancer cells. We here performed genome-wide analysis of DNA methylation of promoter regions by Infinium HumanMethylation27 BeadChip, using 14 clinical papillary thyroid cancer samples and 10 normal thyroid samples. Among the 14 papillary cancer cases, 11 showed frequent aberrant methylation, but the other three cases showed no aberrant methylation at all. Distribution of the hypermethylation among cancer samples was non-random, which implied existence of a subset of preferentially methylated papillary thyroid cancer. Among 25 frequently methylated genes, methylation status of six genes (HIST1H3J, POU4F2, SHOX2, PHKG2, TLX3, HOXA7) was validated quantitatively by pyrosequencing. Epigenetic silencing of these genes in methylated papillary thyroid cancer cell lines was confirmed by gene re-expression following treatment with 5-aza-2′-deoxycytidine and trichostatin A, and detected by real-time RT-PCR. Methylation of these six genes was validated by analysis of additional 20 papillary thyroid cancer and 10 normal samples. Among the 34 cancer samples in total, 26 cancer samples with preferential methylation were significantly associated with mutation of BRAF/RAS oncogene (P = 0.04, Fisher's exact test). Thus, we identified new genes with frequent epigenetic hypermethylation in papillary thyroid cancer, two subsets of either preferentially methylated or hardly methylated papillary thyroid cancer, with a concomitant occurrence of oncogene mutation and gene methylation. These hypermethylated genes may constitute potential biomarkers for papillary thyroid cancer.

Undifferentiated (anaplastic) thyroid carcinoma and iodine intake in Salta, Argentina

This study was conducted to investigate the natural history of undifferentiated thyroid carcinoma (UTC) in the iodine-deficient province of Salta, Argentina, in relation to salt iodization and health care standards. Five hundred ninety-three thyroid cancers diagnosed from 1958 to2012 were reviewed based mainly on the WHO classification and grouped into three periods, one before and two after iodine prophylaxis. The incidence of UTC was analyzed in relation to changing concentrations of potassium iodide (KI) in salt during the prophylaxis period (from 40 to 33.3 mg KI/kg salt), establishment of primary health care centers throughout the region, and use of fine needle aspiration (FNA) cytology. Twenty-nine UTCs were found in the whole series. The frequency of UTC decreased from 15.2 % (9/59 cases) in the first period to 2.6 % (10/381 cases) well after salt iodination (x (2) Fisher's test, p < 0.0002), and the incidence from 1.4/10(6)/year to 0.1/10(6)/year (Student's t test, p < 0.06), respectively. The decline of UTC after iodine prophylaxis occurred even after decreasing concentrations of KI in salt and timely coincided with the establishment of primary health care centers throughout the region and routine use of FNA. The lower rate of UTC after iodine prophylaxis in the province of Salta is mostly related to earlier detection of more differentiated thyroid tumors rather than higher salt iodization.

Increasing incidence of thyroid cancer: controversies explored

Thyroid cancer is the most common endocrine malignancy and its incidence has been increasing considerably in the past few decades. Many studies have been published providing evidence for this increase; however, why thyroid cancer incidence keeps rising is still debated and there are conflicting reports of factors leading to the increase in its incidence. In this article, Nature Reviews Endocrinology asks four experts their opinions on some of the controversies surrounding the changing trends in thyroid cancer incidence.

Lung metastases in patients with differentiated thyroid carcinoma and evaluation of response to radioiodine therapy

INTRODUCTION

The most common site of metastases in differentiated thyroid carcinomas is the lungs. In our study, we aimed to determine the ratios of lung metastases in patients with differentiated thyroid carcinoma and response to radioiodine therapy.

MATERIAL AND METHODS

A total of 542 patients with differentiated thyroid carcinoma who were admitted to our clinic were included in the study. High doses of (131)I were administered to the patients with lung metastases. Response to therapy were evaluated with (131)I scans and stimulated serum Tg levels were examined at least 6 months after therapy.

RESULTS

Lung metastases were detected in 17 (3.1%) of 542 patients with differentiated thyroid carcinoma. Of these patients to whom high doses of (131)I therapy were administered, complete response to therapy was obtained in 5 (29.4%), partial response was obtained in 3 (17.6%) and no response could be obtained in 9 (53%) patients.

CONCLUSION

Although lung metastases from differentiated thyroid carcinomas are rare, those are more common in advanced ages and in males. High doses of (131)I therapy may be partially beneficial in these patients. Thus repetition of therapy is frequently required.

Changes in TNM stage, reoperation and 131-I ablation rate during the use of newer methods for the preoperative diagnosis of differentiated thyroid carcinoma

OBJECTIVE

To define and discuss the changes of important risk factors and TNM staging over the last 40 years in patients operated on for differentiated thyroid carcinoma (DTC), resulting from the introduction of newer sensitive diagnostic procedures in the preoperative evaluation of thyroid nodules.

PATIENTS

We reviewed the medical records of 1251 patients with postoperative diagnosis of DTC who had undergone initial diagnosis, before surgery, at our unit, between 1971 and 2010. According to the period of diagnosis, the patients were divided into four groups (I, II, III, IV) corresponding to the four decades.

RESULTS

The mean age at diagnosis was unchanged over time for both papillary (PTC) and follicular thyroid cancer (FTC). A decrease in the proportion of FTC (group I vs group IV P < 0·01) and a concomitant increase in PTC/FTC ratio was observed particularly in group IV. The significant decrease in the proportion of tumour size of PTC (group I vs group IV, P < 0·01), the increase in the proportion of microcarcinomas, from 22·4% in group I to 53·0% in group IV, P < 0·001, and the decrease in the number of cases with features of aggressiveness have changed the TNM stage towards stages I and II. The overall frequency of patients at high risk was significantly decreased, from 8·0% in group I to 1·8% in group IV. The number of patients who underwent reoperation for the completion of tumour resection and/or radioiodine therapy significantly decreased over time.

CONCLUSIONS

The evaluation of thyroid nodules using the newer diagnostic methods was useful in identifying DTC early. Consequently, the reoperation and thyroid remnant ablation rates were reduced.

Anaplastic transformation of follicular thyroid carcinoma in a metastatic skeletal lesion presenting with paraneoplastic leukocytosis

BACKGROUND

Anaplastic transformation of differentiated thyroid carcinoma (DTC) is a rare event with a poor clinical outcome. It usually occurs in the primary site or in regional lymph nodes, but rarely in distant metastatic lesions.

SUMMARY

A 55-year-old woman with persistent pain in the left hip joint visited our hospital. She had a history of DTC that had been surgically removed 12 years earlier. Clinical images showed a tumorous mass in the left pelvis, indicative of bone metastasis. The patient underwent surgery to remove the tumor and remained stable until local recurrence was found 5 weeks after the surgery. The patient subsequently underwent radiation therapy; however, she died of respiratory failure due to lung metastases 2 months after the surgery for the recurrent lesion. The surgical specimens were diagnosed as anaplastic thyroid carcinoma, indicating that anaplastic transformation of thyroid follicular carcinoma occurred in the metastatic skeletal lesion. In addition, the patient had an unusually high white blood cell count throughout the course. Based on elevated serum granulocyte colony-stimulating factor (G-CSF) levels and positive immunostaining for G-CSF in the surgical specimens, the patient was diagnosed with paraneoplastic leukocytosis.

CONCLUSION

To our knowledge, this is the first case of anaplastic transformation of DTC arising in a metastatic bone lesion described in the literature. In addition, the present case also exhibited severe leukocytosis accompanied by elevated serum G-CSF levels. Clinicians should be aware of the possibility of this occurring in their patients with DTC, as this development calls for a rapid change from observational follow-up to aggressive treatment.

Validity of 6(th) edition of UICC TNM classification system for medullary thyroid carcinoma: a proposal for intraoperative evaluation of T category

Medullary thyroid carcinoma (MTC) accounts for 1.4% of all thyroid malignancies in Japan. Here, we studied the validity of a staging system evaluated preoperatively (Stage), intraoperatively (intra-Stage), and pathologically (pStage) based on the 6(th) and 7(th) UICC TNM classifications. One hundred and nineteen MTC patients who did not show distant metastasis at diagnosis and underwent locally curative surgery were enrolled in this study (average follow-up period: 173.4 months). Twenty-year clinical (not biochemical) disease-free survival (DFS) rates of Stage I, II, III, and IVA patients based on the 6(th) edition were 100, 88.2, 66.8, and 38.9%, respectively. DFS of Stage IVA patients was significantly poorer than that of Stage III patients (p = 0.03137). However, using the 7(th) edition, only 1 patient was classified with Stage III. Intra-Stage III patients based on the 6th edition showed a significantly poorer DFS (20-year DFS 50.0%) than intra-Stage II patients (92.9%) (p = 0.02668), and DFS of intra-Stage IVA patients (38.9%) tended to be poorer than that of intra-Stage III patients (p = 0.05439). Only one patient was classified with intra-Stage III using the 7(th) edition. In pStage, as many as 56 patients (47.1%) were classified with pStage IVA employing both editions. Taken together, Stage and intra-Stage were more useful to accurately discriminate high-risk patients than pStage, and their 6(th) editions were better than 7(th) editions. Although the number of patients was small, our data showed the possibility that intra-Stage in the 6(th) edition was the best staging system for MTC patients.

Anaplastic thyroid cancer: a review of epidemiology, pathogenesis, and treatment

Anaplastic thyroid cancer (ATC) is an uncommon malignancy of the thyroid. Only 1-2% of thyroid cancers are anaplastic, but the disease contributes to 14–50% of the mortality with a median survival of 3 to 5 months. Most patients diagnosed with this disease are 65 years of age or older. The incidence of anaplastic thyroid cancer is decreasing worldwide. Most patients present with a rapidly growing neck mass, dysphagia, or voice change. We performed a comprehensive literature search using PubMed focusing on the treatment of anaplastic thyroid cancer including historical review of treatment and outcomes and investigations of new agents and approaches. A total of sixteen chart review and retrospective studies and eleven prospective studies and/or clinical trials were reviewed. The current standard therapeutic approach is to consider the disease as systemic at time of diagnosis and pursue combined modality therapy incorporating cytoreductive surgical resection where feasible and/or chemoradiation either concurrently or sequentially. Doxorubicin is the most commonly used agent, with a response rate of 22%. Several new agents are currently under investigation. Referral of patients for participation in clinical trials is needed.

Alternative surgical strategies and favorable outcomes in patients with medullary thyroid carcinoma in Japan: experience of a single institution

BACKGROUND

Medullary thyroid carcinoma (MTC) accounts only for 1.4% of all thyroid malignancies in Japan. Since 1996, we have performed hemithyroidectomy, instead of total thyroidectomy, for sporadic nonhereditary MTC when the primary lesion is located in only one lobe. Regarding lymph node dissection, modified radical neck dissection (MND) at least ipsilateral to the tumor has been routinely performed, even if there is no clinically apparent metastasis. We investigated the clinical outcomes of MTC patients in our department.

METHODS

A series of 118 patients with MTC who underwent initial surgery between 1975 and 2005 were enrolled in this study. The RET gene mutations were analyzed for all patients and 46 had germline RET gene mutations. Of those 46 patients, 26 were diagnosed as MEN 2A and 2 were diagnosed as MEN 2B. Postoperative follow-up periods averaged 141 months.

RESULTS

Of 115 patients who did not have distant metastasis at surgery and who underwent locally curative surgery, 78 (67.8%) were biochemically cured. All patients without pathological lymph node metastasis were biochemically cured, and 44.8% of patients with node metastasis were also biochemically cured. The 10-year and 20-year disease-free survival rates were 89.0% and 82.5%, respectively. None of the patients who did not show lymph node metastasis and only 2 (2.6%) of 78 patients who were biochemically cured showed clinically apparent carcinoma recurrence. The 10-year and 20-year cause-specific survival rates were 96.6% and 91.7%, respectively. Lymph node metastasis, tumor size>4 cm, extrathyroid and extranodal tumor extensions significantly affected cause-specific survival of patients.

CONCLUSIONS

Clinical outcomes of MTC patients in our series were better than those in Western countries, a result that might have resulted in part because of our routine MND regardless of whether clinically apparent node metastasis was detected.

Prognostic factors and therapeutic strategies for differentiated carcinomas of the thyroid

Differentiated thyroid carcinoma originates from thyroid follicular cells and is the most prominent malignancy of the endocrine organs. There are two histological types of differentiated carcinoma, namely, papillary and follicular carcinoma. According to reports from Western countries, papillary carcinoma comprises 85.3% of thyroid malignancies in whites, and 72.3% in blacks. In Japan, a previous study showed that the prevalence of papillary carcinoma was 78.4% based on material registered between 1977 and 1986, but according to recent findings reported in 2004 by Japanese Society of Thyroid Surgeons (JSTS), papillary carcinoma accounted for as much as 93% of all thyroid carcinomas. Papillary carcinoma frequently metastasizes to the regional lymph node and shows multicentricity in the thyroid gland. It usually shows a typical ultrasonographic appearance and can be rather easily diagnosed by fine needle aspiration biopsy (FNAB). Follicular carcinoma accounts for 10.9-20.5% of the patients in the United States. In Japan, the prevalence of follicular carcinoma was reported to be 17.2%, but it decreased to 5% in a report by JSTS in 2004. This carcinoma is only occasionally diagnosed preoperatively, because it is hard to discriminate follicular carcinoma from benign adenoma on imaging studies and cytologic findings. In contrast to papillary carcinoma, follicular carcinoma more often metastasizes to distant organs than regional lymph nodes. In Japan, the prevalence of papillary carcinoma increased and that of follicular carcinoma decreased between reports from 1977 to 1986 and that in 2004, which may be because follicular variant of papillary carcinoma was classified into follicular carcinoma in the previous results. Generally, these carcinomas show an indolent character, but when the lesion dedifferentiates and becomes undifferentiated carcinoma, it displays very rapid growth with an adverse prognosis and is regarded even as the most aggressive malignancy among human solid carcinomas. Furthermore, cases showing certain characteristics are likely to be constantly progressive and even become life-threatening. Such cases should be regarded as "high-risk" requiring careful and extensive surgical treatment and postoperative follow-up. Indeed, it is most important for physicians to correctly distinguish high-risk cases from those with an indolent character, although how to evaluate the biological characteristics of thyroid carcinoma and how to identify high-risk cases remains highly controversial. In this review, the methods of distinguishing high-risk cases and the appropriate therapeutic strategies for papillary and follicular carcinomas predominantly based on our experience are emphasized and our proposals for therapies including surgical treatment are demonstrated.

Anaplastic thyroid cancer

Anaplastic thyroid cancer is an uncommon, typically lethal malignancy of older adults with no effective systemic therapy. The mean survival time is usually less than 6 months from the time of diagnosis and, unfortunately, this outcome is not fundamentally altered by available treatments. Histologic tissue confirmation is recommended if the diagnosis is not absolutely certain to exclude tumors with better prognosis or that require different treatment. Patency of the airway should be kept in mind throughout the patient's course and individuals with impending airway obstruction, in the absence of imminent death from other sites of disease, should be considered for a tracheostomy to secure the airway. Enrollment in meaningful clinical trials should be given the highest priority at all decision points.

Thyroid cancer, thyroiditis and dietary iodine: a review based on the Salta, Argentina model

Factors that should be considered when studying the effect of dietary iodine in the development of thyroid cancer include pathological criteria, diagnostic techniques, screening programs, radioactive fallout, and standard of medical care in the studied population. In most surveys, papillary carcinoma forms the largest group of thyroid malignancies, both before and after iodine prophylaxis where an increase in the papillary:follicular carcinoma ratio is also noted. Undifferentiated carcinomas decrease after salt prophylaxis. In Salta, Argentina, the increasing incidence of clinically significant papillary thyroid cancer and the decrease of undifferentiated carcinoma after iodine prophylaxis are probably due to better access to health centers and consequent earlier detection of differentiated precursor tumors. Autoimmune focal and diffuse or Hashimoto's thyroiditis are linked to dietary iodine. Pathological studies made in different regions indicate that these types of thyroiditis occur more frequently in areas of iodine sufficiency than in areas of iodine deficiency, and increase after iodine prophylaxis both in non-goitrous and iodine-deficient areas like Salta, Argentina. An increase of lymphocytic thyroiditis could be linked to an increased incidence of primary thyroid lymphoma, and thyroiditis is more commonly associated with papillary carcinoma than with other types of thyroid follicular or C-cell derived carcinomas regardless of iodine intake.

A case-control study in Hiroshima and Nagasaki examining non-radiation risk factors for thyroid cancer

BACKGROUND

Because little is known about the etiology of thyroid cancer in Japan, we conducted a case-control study of thyroid cancer and lifestyle and other risk factors. The present report focuses on medical history, family history, smoking and alcohol drinking, and their interactions with radiation exposure.

METHODS

Thyroid cancer cases reported to the Hiroshima and Nagasaki tumor registries during 1970-1986 were histologically reviewed by pathologists. For each of 362 cases with papillary or follicular adenocarcinoma diagnosed at <75 years of age, one control without cancer matched on city, sex, year of birth, and atomic-bomb radiation exposure was selected from the Life Span Study cohort or the offspring cohort. The cohort subjects were residents of Hiroshima and Nagasaki with or without atomic-bomb radiation exposure. Information on risk factors was obtained through a pre-structured interview carried out in 1986-1988.

RESULTS

Analysis using conditional logistic regression showed history of goiter or thyroid nodule and family history of cancer to be significantly associated with an increased odds ratio for thyroid cancer. Smoking and alcohol drinking were significantly and independently associated with a reduced odds ratio. Interaction between smoking and alcohol drinking was not evident based on either an additive model or a multiplicative model. Radiation exposure did not significantly modify the associations between these factors and thyroid cancer risk.

CONCLUSION

History of goiter/nodule and family history of cancer were risk factors for thyroid cancer. Smoking and alcohol drinking were independently associated with reduced risk. Self-reported retrospective information presents some limitations in interpretation of the data.

A review of 227 cases of small papillary thyroid carcinoma

AIMS

To review differences in biological aggressiveness, clinical behaviors or selected surgical treatments between the PMC and the slightly larger PTC of 1.0<T<or=2.0 cm.

METHODS

Two hundred and twenty-seven cases of papillary thyroid carcinoma not larger than 2.0 cm, diagnosed and treated at the Kuma Hospital, Kobe, Japan, with a 10-year follow-up from 1992 to 2003, were reviewed.

RESULTS

The small PTCs demonstrated excellent outcomes, and persistent/recurrent disease was identified in only nine patients (4%). None of the patients died of the disease. A multivariate analysis revealed that massive extrathyroidal extension at presentation was the only independent prognostic factor for locoregional recurrence. Subdivision into PMCs and slightly larger tumors (1<T<or=2 cm) did not affect the excellent outcomes, but the patients in the latter subgroup received more lymph node surgery and displayed more aggressive clinico-histological features such as higher rates of extrathyroidal extension, lymph node metastasis, loss of polarity, invasive growth pattern and loss of cohesiveness.

CONCLUSIONS

Small PTC not larger than 2.0 cm could be considered as favorable a prognosis as PMC.

Anaplastic Thyroid Carcinoma: Biology, Pathogenesis, Prognostic Factors, and Treatment Approaches

BACKGROUND

Anaplastic thyroid carcinoma (ATC) is one of the most aggressive solid tumors known to affect humans and carries a dismal prognosis. Our primary aim was to review its epidemiology, biology, risk factors, and prognostic indicators. We also reviewed the individual and combined roles of surgery, radiotherapy, chemotherapy, and newer therapeutic options in the management of ATC.

METHODS

An extensive literature review was conducted to include all published reports on ATC. The changing trends in the management of anaplastic thyroid cancer were analyzed to summarize the current practice of management of ATC.

RESULTS

Although ATC is rare, there has been a decline in its incidence worldwide. ATC accounts for more than half of the 1200 deaths per year attributed to thyroid cancer. Long-term survivors are rare, with >75% and 50% of patients harboring cervical nodal disease and metastatic disease, respectively, at presentation. ATC can arise de novo or from preexisting well-differentiated thyroid cancer. Surgical management has shifted from tracheostomy only for palliation to curative resection when possible. Tracheostomy is performed for impending obstruction rather than for prophylaxis. Radiotherapy has evolved from postoperative administration only to preoperative treatment, combining preoperative and postoperative treatment and using higher doses, along with hyperfractionating and accelerating dose schedules. Chemotherapy has changed from monotherapy to combination therapy, and newer drugs such as paclitaxel show promise. Similarly, novel angiogenesis-inhibiting agents are currently being used, with early reports of some benefit.

CONCLUSIONS

Despite multimodality approaches, ATC still carries a dismal prognosis. This should provoke innovative strategies beyond conventional methods to tackle this uniformly lethal disease.

RET gene rearrangements (RET/PTC1 andRET/PTC3) in papillary thyroid carcinomas from an iodine-rich country (Japan)

BACKGROUND

The frequency of RET rearrangements (RET/PTC) in papillary thyroid carcinomas varies significantly according to geographic area, with the greatest incidence reported in the Belarus region, which is iodine-deficient and was contaminated severely after the Chernobyl reactor accident, and with the lowest incidence in iodine-rich, nonirradiated Japan. The authors investigated the prevalence of RET/PTC in a large number of thyroid tumors from Japanese patients.

METHODS

Fresh and paraffin embedded tumor tissues from 215 Japanese patients were examined for RET rearrangements (RET/PTC1 and RET/PTC3) by means of reverse transcriptase-polymerase chain reaction analysis, with primers flanking the chimeric region, followed by direct-sequence analysis.

RESULTS

RET/PTC was found only in papillary carcinomas and was not observed in other histologic types of thyroid tumors. The overall frequency of RET/PTC in papillary carcinomas was 28.4%, with a greater frequency in younger patients, including 41.9% of younger patients age < 20 years, 27.6% of patients age 20-40 years, and 24.8% of patients age > 40 years. Among the patients in these 3 age groups, the prevalence rate of RET/PTC1 was similar, but RET/PTC3 was observed most frequently among patients age < 20 years. When the tumors were grouped further according to histologic subtypes, the prevalence of RET/PTC3 was greater in solid/solid-follicular papillary carcinomas than in classic papillary carcinomas.

CONCLUSIONS

The results indicated that RET/PTC may be useful as a specific molecular marker for papillary thyroid carcinomas. Furthermore, its incidence in such tumors was not low in Japanese patients, and it seemed to be associated with patient age. Therefore, the current results raise questions regarding the belief that the frequency of RET/PTC differs geographically and is especially low in Japan.

Immunohistochemical and sequencing analyses of the Wnt signaling components in Japanese anaplastic thyroid cancers

We investigated the status of the components and target genes of the Wnt signaling pathway in Japanese anaplastic thyroid cancers (ATCs) in the present study. Nuclear and cytoplasmic positive staining of beta-catenin, which might indicate the existence of alterations in the Wnt signaling pathway, were found in 40.9% and 63.6% of the 22 ATC samples, respectively. The beta-catenin, adenomatous polyposis coli (APC) and Axin 1 gene mutations were observed in 4.5%, 9.0%, and 81.8% of the 22 ATC samples, respectively. Overexpression of cyclin D1 and c-myc, which are the target genes of the Wnt signaling pathway, was observed in 27.3% and 59.1% of the ATC samples, respectively. There was no significant correlation between nuclear or cytoplasmic positive staining of beta-catenin and nuclear positive staining of cyclin D1 or c-myc. Taken together, the results of beta-catenin immunohistochemistry suggest that alterations in the Wnt signaling pathway are associated with carcinogenesis of ATC, but the frequency of beta-catenin gene mutation in our series is lower than that previously reported. Furthermore, cyclin D1 and c-myc frequently accumulated in ATC, independently of dysfunction in the Wnt signaling pathway.

Benign follicular thyroid lesions versus follicular variant of papillary carcinoma: differentiation by architectural pattern

Differentiation between benign and malignant follicular lesions is one of the difficult diagnostic areas in thyroid fine needle aspiration (FNA). Nuclear criteria are usually used to distinguish between them. In this study the microarchitectural pattern of common benign follicular lesions, namely nodular hyperplasia (NH) and follicular adenoma (FA) were analysed in comparison with those of follicular variant of papillary carcinoma (FVPC) in order to aid in their differentiation. The FNA smears of histologically proven cases of FVPC, NH and FA were reviewed and compared. The microarchitectural features of FVPC, NH and FA were described. Three cytological features--multi-layered rosettes, branching monolayered sheets and balls of thick pinkish colloid--were exclusively observed in FVPC. Hyperplastic papillae with intact follicles and colloid were frequently seen in NH, 83% and 100%, respectively. Albeit less frequently, they were also noted in FVPC, 25% and 75% of cases, respectively. These overlapping features make the distinction between FVPC and NH sometimes difficult; however, assessing the smears for the specific features of FVPC may help in their differentiation. None of the aforementioned microscopic findings with the exception of the seldom presence of colloid were documented in FA. The crowded clusters of follicular cells were seen both in FA and FVPC; however, they were complex and branching in the latter and round to oval in the former. Finally, smears with good recovery of material are indispensable for the identification of these helpful microarchitectural patterns.

A novel classification system for patients with PTC: addition of the new variables of large (3 cm or greater) nodal metastases and reclassification during the follow-up period

BACKGROUND

Several factors have been proven to be useful for classifying patients with papillary thyroid carcinoma (PTC) into either low- or high-risk groups. However, the relative importance of prognostic factors, including lymph nodal metastasis, remains unclear.

METHODS

A total of 604 patients who underwent initial surgery for PTC (diameter of tumor>1 cm) were analyzed. The mean duration of follow-up was 10.7 years.

RESULTS

By multivariate analysis for disease-specific survival, distant metastasis was the only significant risk factor (risk ratio=65.1) for younger patients (age<50). For older patients (age> or =50), distant metastasis (risk ratio=6.7), extrathyroidal invasion (risk ratio=2.4), and large nodal metastasis (> or =3 cm; risk ratio=5.3) had relative importance. From the results, younger patients with distant metastasis and older patients with any of the 3 factors were defined as at high risk, whereas the other patients were defined as at low risk. Overall, 106 patients at high risk (18%) and 498 patients at low risk (83%) had 10-year survival rates of 69% and 99%, respectively. Only 3 patients of the low-risk group died from the disease. Among postoperative factors, recurrence within 3 years after initial surgery was the most important risk factor for cancer death. Of the high-risk group, patients with a disease-free interval of >3 years showed an excellent outcome (96% of a 10-year survival rate), similar to patients in the low-risk group.

CONCLUSIONS

A novel classification system, in which large nodal metastases and postoperative reclassification were added, was devised. This was useful for choosing proper therapeutic strategies, offering rational information, and determining adequate postoperative follow-up schemes for individual patients with PTC.

Changing trends of incidence and prognosis of thyroid carcinoma in lower Franconia, Germany, from 1981-1995

BACKGROUND

A population-based registry (PBR) in Lower Frankonia in southern Germany was conducted to evaluate the changes of incidence and prognosis of thyroid carcinoma (TC) in this area.

METHODS

The study comprised 476 patients with differentiated thyroid carcinoma (DTC) from Lower Franconia (1.3 x 10(6) inhabitants) registered between 1981 and 1995 at the Regional Tumor Center. The incidence was assessed with respect to gender, age, histology, tumor stage, lymph node involvement and distant metastases in 5-year intervals (1981-1985, 1986-1990, and 1991-1995).

RESULTS

An increasing rate of papillary thyroid carcinoma PTC and a decreasing rate of follicular thyroid carcinoma (FTC) were observed over the three time periods (1981-1985, 1986-1990, and 1991-1995). The overall incidence revealed no significant change with time for both females from 3.22 to 3.25 and 3.73 and males (1.07 to 1.54 and 1.69) between the three time periods. There was a significant improvement in outcome of patients with DTC with respect to life expectancy.

CONCLUSIONS

Iodine prophylaxis does influence the distribution of the histologic types of thyroid cancer and leads to an increase in the ratio of papillary versus follicular carcinoma. Our study supports the hypothesis that the benefits of correcting iodine deficency outweigh the risks of iodine supplementation.

Changes in Clinical Presentation, Management and Outcome in 1348 Patients with Differentiated Thyroid Carcinoma: Experience in a Single Institute in Hong Kong, 1960–2000

The clinical features, management and outcome of 1348 patients diagnosed with differentiated thyroid carcinoma in Queen Elizabeth Hospital, Hong Kong, were analysed according to the period of diagnosis: A (before 1980), B (1981-1990) and C (1991-2000). As time advanced, ratio of papillary carcinoma (PTC) to follicular carcinoma (FTC) increased (A:B:C = 1.6: 3.1: 7.2). The mean size of the primary tumour decreased (A:B:C = 3.5 cm: 2.8 cm: 2.5 cm), with a greater percentage of microcarcinoma of 1 cm or less (A:B:C = 5.1%: 16.1%: 21.7%). At presentation, the incidence of lymph-node metastasis decreased (A:B:C = 32.7%: 31.6%: 24.8%) and that of distant metastasis decreased (A:B:C = 9%: 6.1%: 5.3%). Bilateral surgical resection was more commonly used (A:B:C = 62.8%: 89.1%: 94.8%) than lobectomy (A:B:C = 26.3%: 2.8%: 1.8%). Radiation treatment, radioactive iodine (131I; RAI) and external radiotherapy (EXT), was more commonly used (A:B:C = 53.2%: 74.7%: 85.1%). RAI was used in 84.3% (A:B:C = 50%: 71.2%: 84.3%) and EXT in 14.5% of patients in the past decade (A:B:C = 10.9%: 8.7%: 14.5%). The proportion of patients who adopted a bilateral surgery and RAI treatment increased gradually with time (A:B:C = 33%: 68%: 83.8%). The 5-year cause-specific survival (A:B:C = 90.2%: 93.7%: 95.7%), locoregional failure-free survival (A:B:C = 72.6%: 82.9%: 91.6%) and distant metastasis failure-free survival (A:B:C = 84.5%: 89.1%: 92.6%) were improved. However, the period of diagnosis was not found to be an important explanatory variable (i.e. P > 0.05) in Cox regression after adjusting for other factors, indicating that the improvement was probably related to the temporal trend of other factors: presentation at earlier stage, increased ratio of PTC:FTC and more aggressive management by bilateral surgery and radiation therapy.

The role of FNA in the initial management of thyroid lesions: 7-year experience in a district general hospital

Fine needle aspiration (FNA) cytology plays a major role in the diagnosis of the thyroid lesions in university hospitals and tertiary referral institutions. Our aim was to find out if this was possible in small district hospitals with limited resources. Over a 7-year period, from October 1994 to April 2002, 303 patients with thyroid swellings underwent FNA with an overall adequacy rate of 97.7%. FNAs were performed specifically by the pathologists, so that our inadequacy rate, 2.3% was far lower than 11-29% reported elsewhere. The FNA findings were compared with subsequent histology results in 67 cases. The diagnosis of benign and neoplastic lesions was predicted accurately by FNA in 93% and 94.7% of cases, respectively. The latter reached 100% if results of FNA in follicular neoplasms were excluded. Sensitivity and specificity were 85.6% and 97.6%, respectively, which is comparable with results from tertiary institutions. The commonest thyroid lesions in our hospital were nodular goitre (52.4%), followed by thyroiditis (17.6%) and neoplasia (13.9%). We conclude that, with the availability of appropriate personnel, FNA is feasible as the major modality in district general hospitals. FNA in follicular lesions remains challenging but could be overcome in part by recognizing the criteria to differentiate follicular variant of papillary carcinoma and other follicular proliferations. Aspiration, smearing, staining and interpretation should be left to pathologists or other well-trained personnel to ensure good quality and consistency.

Elevation of serum pro-gastrin-releasing peptide in patients with medullary thyroid carcinoma and small cell lung carcinoma

Medullary thyroid carcinoma (MTC) arises from parafollicular or C cells of the thyroid gland and produces a variety of peptides such as calcitonin (CT) and gastrin-releasing peptide (GRP). Here we measured serum levels of pro-gastrin-releasing peptide (Pro-GRP), a more stable precursor of GRP, in 15 patients with MTC (4 males, 11 females) who did not show any clinical or radiologic signs of small cell lung cancer. Serum Pro-GRP levels were elevated in 80% (12/15) patients. Significant correlation was observed between serum Pro-GRP and CT (r = 0.52) and carcinoembryonic antigen (CEA) (r = 0.56). Serum Pro-GRP levels also correlated with tumor size (r = 0.70). Serum Pro-GRP levels also decreased below the cut-off range in one patient after surgical resection. Our data suggest that Pro-GRP, which is considered to be a specific marker for small cell lung carcinoma, seems to be also helpful and additional marker for the diagnosis and monitoring the response to therapy in patients with MTC in addition to calcitonin as the main tumor marker.

Immediate causes of death in thyroid carcinoma: clinicopathological analysis of 161 fatal cases

Most patients with thyroid carcinoma have a good prognosis. Due to the small number of fatal cases, it has not been clarified what conditions result in death for patients with thyroid carcinoma. To provide appropriate management for advanced thyroid carcinoma patients, we analyzed causes of death in 161 fatal cases. Clinical characteristics and immediate (final) causes of death based on pathological conditions were analyzed in 62 anaplastic carcinomas and 99 fatal differentiated carcinomas. Single fatal conditions could not be specified in 55 patients. In the remaining 106 patients, respiratory insufficiency (43%) was the most common specific fatal condition, followed by circulatory failure (15%), hemorrhage (15%), and airway obstruction (13%). Respiratory insufficiency due to remarkable pulmonary metastasis replacing lung tissue, massive hemorrhage and airway obstruction due to uncontrolled local tumors, and circulatory failure resulting from compression of the vena cava by extensive mediastinal or sternal metastases were found to be the most important immediate causes of death. Based on this knowledge, several palliative procedures may be worth considering to improve survival and quality of life in patients with advanced thyroid carcinoma.

Evaluation of routine basal serum calcitonin measurement for early diagnosis of medullary thyroid carcinoma in seven hundred seventy-three patients with nodular goiter

The aims of the study were to identify medullary thyroid cancer (MTC) in its earliest stages by screening patients with basal calcitonin measurements and to determine whether basal serum calcitonin measurements should be a part of the routine evaluation of a nodular goiter. Basal serum calcitonin levels were obtained from 75 patients (female:male 57:18, mean age 42.8 years, range with 18-76 years) with nonnodular thyroid disease as controls. Their mean basal calcitonin level was 7.8+/-0.4 pg/mL with a range of 5-27 pg/mL. Seven hundred seventy-three patients with nodular goiter were included in the study (female:male 586:187) with the mean age of 46.1 years (range 17-78). Four patients had elevated basal serum calcitonin levels ranging between 150-1000 pg/mL. These 4 patients underwent surgery. MTC was confirmed by histopathology in all 4. One patient's mother and brother were also diagnosed as MTC as a result of family screening. Basal serum calcitonin levels were higher than 150 pg/mL in these patients. Fine needle aspiration biopsy (FNAB) of 2 of 4 MTC patients were incorrectly diagnosed as papillary carcinoma; another had malignant cytology and the fourth had benign cytology. None were diagnosed as MTC on the basis of FNAB. In conclusion, calcitonin measurement is an effective method for the diagnosis of MTC. Measurement of basal calcitonin levels in patients with malignant or suspicious FNAB may be a cost-effective approach to screen for MTC. High basal serum calcitonin levels increase the chance of curative therapy by diagnosing MTC in the early stages. It is superior to FNAB for diagnosis of MTC.

Epidemiology of thyroid diseases in iodine sufficiency

Epidemiology of thyroid diseases in iodine-sufficient areas (ISA) deals with sporadic goiter, thyroid autoimmune diseases, and thyroid cancer. A comparison between the different studies performed is difficult because methods have changed over time and selection criteria and definitions such as prevalence or incidence were not used consistently by some authors. Sporadic goiter: in ISA, autoimmune processes play a major role in the development of sporadic goiter. In adults, sporadic diffuse goiter is most frequent in young women (16%), perhaps due to additional relative iodine deficiency especially in pregnancy, and declines with age (<10%). Sporadic nodular goiter increases from 5% in young women to 9% in older women. Autoimmune thyroid disease (AITD): thyroid autoantibodies (TAb) and histopathological lymphocytic infiltration of the thyroid is much more common in ISA (4.6% in women; 1.1% in men) than in iodine-deficient areas (IDA). The prevalence and incidence of hypothyroidism and hyperthyroidism varies, depending on whether overt and subclinical forms are included and whether newly or previously diagnosed dysfunction is considered. In an overview of the literature, the prevalence is 2 in 1000 for overt and 6 in 1000 for subclinical hyperthyroidism in ISA. The values for hypothyroidism are 5 in 1000 and 15 in 1000, respectively. Change from IDA to ISA: in former IDA, the percentage of hyperthyroidism increases up to 4 years after salt iodination. Whereas this effect is transient for Plummer's disease, a change from IDA to ISA seems to lead to a permanent increase in overt and subclinical Graves' disease. Thyroid cancer: most studies demonstrate that the histopathological types of thyroid cancer are different in IDA and ISA. There is a tendency toward an increase in differentiated and decrease of anaplastic cancer. The ratio of papillary to follicular thyroid cancer ranges from 6.5:1 to 3.4:1 in areas with high iodine intake, decreases 3.7:1 to 1.6:1 in areas with moderate iodine intake, and ranges from 1.7:1 to 0.19:1 in IDA.

Sporadic medullary microcarcinoma of the thyroid: a retrospective analysis of eighty cases

Clinical characteristics and prognosis of 80 patients (53 women and 27 men) with sporadic medullary thyroid carcinomas (MTC), less than 1 cm in size (micro-MTC), operated on between 1971 and 1996 are reported (73 total and 7 partial thyroidectomies). These patients, obtained from a national database of 899 patients with MTC, were compared with 357 cases of sporadic MTC greater than 1 cm and 149 subjects with familial MTC less than 1 cm (familial micro-MTC). Median age at surgery was 52.5 years, a distribution similar to larger sporadic MTC. Micro-MTC was identified due to elevated calcitonin (47.5%), clinically identified lymph node (10.0%), distant metastases (6.3%) or pathologic finding at surgery (36.2%). Diarrhea and/or flushing were observed in 6 patients including 4 with clinically identified lymph node. Among patients who had lymph node dissection at surgery (68.8%), lymph node involvement with tumor was observed in 30.9%, and was significantly more frequent in multifocal (7/11) than in unifocal micro-MTC (p < 0.03). All sporadic micro-MTC were unilateral. Survival rate was 93.9% +/- 4.4% (SE) at 10 years, greater than that observed in sporadic macro-MTC (p = 0.04). Normal postoperative basal calcitonin (CT) was obtained in 71.1% of micro-MTC patients versus 33.6% in sporadic macro-MTC (p < 0.01). Sporadic micro-MTC is much more frequent than expected, 15% of MTC in our series. Although specific survival rate and percentage of biological cure in micro-MTC are significantly better than for larger tumors, the frequency of lymph node involvement, however, justifies an aggressive surgical approach including total thyroidectomy and bilateral central lymph node dissection.

Postoperative outcome of insufficient surgery for small differentiated thyroid carcinoma

We performed conservative surgery for small differentiated thyroid carcinoma, but also inadvertently carried out minimal insufficient surgery, such as enucleation (Ex) or partial lobectomy (pLx) without regional node dissection for malignant thyroid nodules. In this study, the long-term postoperative outcome after such insufficient surgical treatment was evaluated. Of 348 patients with differentiated thyroid carcinoma who underwent initial surgery between 1953 and 1976, 84 underwent either Ex or pLx and their records are herein reviewed. The frequency of recurrence from the remnant gland or regional lymph nodes was examined in relation to the tumor diameter (< or = 1.0 cm, tis; 1.0 cm-2.0 cm, t1; > 2.0 cm, t2). After Ex/pLx, the recurrence rate in the tis group was 13.3% and not significantly different from that (13.6%) in the t1 group. The recurrence rate was notably increased in the t2 group. Moreover, there was no significant difference between the recurrence rate in the tis and t1 groups after Ex/pLx and that after lobectomy with nodal dissection. These results suggest that a reoperative procedure with a more extensive thyroidectomy and neck dissection might not necessarily be required immediately after minimal insufficient surgery is inadvertently carried out in patients with small differentiated thyroid carcinoma measuring 2.0 cm in diameter or less.

Normal human intrathyroidal iodine

Excessive or deficient iodine intake results in a variety of human thyroid dysfunction and disorder. The main part in the etiology of these disorders relates to the concentrations of intrathyroidal iodine which is important to regulate thyroid function and state. Instrumental neutron activation and X-ray fluorescent analyses were used to study the age dynamics of intrathyroidal iodine. Concentration and the total content of iodine in the thyroid were estimated in necropsy samples of 70 men and 20 women aged 2-87. Both thyroid lobes were weighed, lyophilised and homogenised. Iodine was analysed in approximately 50-mg samples. The mean intrathyroidal iodine concentration (mean +/- S.E.) of a normal subject aged 26-65 averaged 345 +/- 21 micrograms g-1 dry tissue in non-endemic goitre region with no obligatory salt iodination. Maximum iodine concentration was found to be 494 +/- 65 micrograms g-1 (P < 0.05) for the age of 16-25. A statistically reliable second increase of iodine was shown for the elderly which was 668 +/- 60 micrograms g-1 (P < 0.001) for the age over 65. Human intact thyroid weight for the age over 15 does not change and averages 14.2 +/- 0.4 g. Both left and right lobes of intact thyroid do not differ in weight, iodine concentration and the total content. An inverse correlation was found between thyroid weight and intrathyroidal iodine concentration (-0.32, P < 0.01). The range of intrathyroidal iodine parameters is wide enough to provide a possible explanation for the particular sensitivity of some population to both excessive and deficient iodine intake. Similarity of intrathyroidal iodine age dynamics and incidence of new cases of thyroid carcinoma were to confirm the hypothesis of intrathyroidal iodine importance in cancer etiologies suggested before.

Incidence and clinical characteristics of thyroid carcinoma after iodine prophylaxis in an endemic goiter country

Iodized salt prophylaxis has been performed in Austria since 1963. Through this approach, mean urinary iodine excretion has been normalized to 144+/-23.5 microg/g creatinine per day. Thus Tyrol is no longer an endemic goiter area. We have analyzed the impact of iodized salt prophylaxis on thyroid cancer (TC) comparing data from the early 1960s with those corresponding to the period 1986 to 1995, when iodine supply was normalized. The study included 439 patients from Tyrol and Southern Tyrol. The incidence of TC in Tyrol has risen during the past decades from 3.07 between in 1957 and 1970 to 7.8 between 1990 and 1994 (CR/100000/year). We observed a rise in the percentage of differentiated adenocarcinomas (56% to 91.5%) with a predominance of papillary TC (54.4%) along with a decrease of anaplastic TC. In addition to these histological features, a shift to less advanced TNM stages, eg, T1-3, N0-1a, M0, was obvious, increasing from 29% to 72.2%, whereas advanced tumors, ie, T4 or N1b or M1, decreased from 71% to 28%. These changes have significantly improved prognosis. The current 5-year survival rate is 90.7% as compared with a rate of 73% in the 1960s; the values for 7-year survival are 89% and 48%, respectively. The marked effects of age, tumor stages, and histology on prognosis were confirmed with the Kaplan-Meier method. We conclude that together with normalization of iodine supply in an endemic goiter region the epidemiological profile of TC has changed. Even though the incidence of TC has risen, prognosis has significantly improved due to a shift towards differentiated forms of TC that are diagnosed at earlier stages.

Thyroid cancer histotype changes as observed in a major general hospital in a 21-year period

The existing registries of thyroid carcinoma are seldom comparable as far as epidemiological data, diagnostic criteria and histopatological description are concerned. Epidemiological studies report a progressive increase in the incidence of thyroid carcinoma in the last twenty years and in both sexes this increase of incidence has been referred to papillary histotype. Data collected from surgical series show a rate of thyroid carcinomas from 7 to 20% of total thyroid surgeries. The present study was designed in order to obtain a retrospective review of the distribution of thyroid carcinoma's different histotypes in the last 21 years in a major General Hospital. Detailed analysis of patients with histologically confirmed thyroid carcinoma admitted between 1974 and 1994 to the Surgery Department of Mauriziano Hospital of Torino, Italy showed an overall 11.8% prevalence of thyroid cancer out of the total thyroid surgeries. The rate of papillary carcinoma was the highest (54.3%) followed by follicular carcinoma (27.6%), anaplastic carcinoma (11.1%), medullary carcinoma (4.6%) and others (2.4%). The papillary-to-follicular ratio varied from 0.60 in 1974-76 to 6.88 in 1992-94. Female to male ratio of all thyroid carcinoma histotypes was 2.0 or more; papillary and follicular histotypes had the highest ratio. The variations of the histotype rate observed may be consequence of the silent increase of daily iodine intake throughout the subsequent years, while improved diagnostic tools available and increased experience of the medical staff have probably increased the number on thyroid ablations performed. Our data confirm the changing epidemiology of thyroid carcinoma, reported by international literature.