Prediagnostic serum concentrations of per- and polyfluoroalkyl substances and risk of papillary thyroid cancer in the Finnish Maternity Cohort

Human exposure to per- and polyfluoroalkyl substances (PFAS) occurs globally through contaminated food, dust, and drinking water. Studies of PFAS and thyroid cancer have been limited. We conducted a nested case-control study of prediagnostic serum levels of 19 PFAS and papillary thyroid cancer (400 cases, 400 controls) in the Finnish Maternity Cohort (pregnancies 1986-2010; follow-up through 2016), individually matched on sample year and age. We used conditional logistic regression to estimate odds ratios (OR) and 95% confidence intervals (CI) for log2 transformed and categorical exposures, overall and stratified by calendar period, birth cohort, and median age at diagnosis. We adjusted for other PFAS with Spearman correlation rho = 0.3-0.6. Seven PFAS, including perfluoroctanoic acid (PFOA), perfluorooctanesulfonic acid (PFOS), N-ethyl-perfluorooctane sulfonamidoacetic acid (EtFOSAA), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), and perfluorohexane sulfonic acid (PFHxS) were detected in >50% of women. These PFAS were not associated with risk of thyroid cancer, except for PFHxS, which was inversely associated (OR log2  = 0.82, 95% CI: 0.70-0.97). We observed suggestive but imprecise increased risks associated with PFOA, PFOS, and EtFOSAA for those diagnosed at ages <40 years, whereas associations were null or inverse among those diagnosed at 40+ years (P-interaction: .02, .08, .13, respectively). There was little evidence of other interactions. These results show no clear association between PFAS and papillary thyroid cancer risk. Future work would benefit from evaluation of these relationships among those with higher exposure levels and during periods of early development when the thyroid gland may be more susceptible to environmental harms.

Cancer overdiagnosis: a challenge in the era of screening

"Screening" is a search for preclinical, asymptomatic disease, including cancer. Widespread cancer screening has led to large increases in early-stage cancers and pre-cancers. Ubiquitous public messages emphasize the potential benefits to screening for these lesions based on the underlying assumption that treating cancer at early stages before spread to other organs should make it easier to treat and cure, using more tolerable interventions. The intuition is so strong that public campaigns are sometimes launched without conducting definitive trials directly comparing screening to usual care. An effective cancer screening test should not only increase the incidence of early-stage preclinical disease but should also decrease the incidence of advanced and metastatic cancer, as well as a subsequent decrease in cancer-related mortality. Otherwise, screening efforts may be uncovering a reservoir of non-progressive and very slowly progressive lesions that were not destined to cause symptoms or suffering during the person's remaining natural lifespan: a phenomenon known as "overdiagnosis." We provide here a qualitative review of cancer overdiagnosis and discuss specific examples due to extensive population-based screening, including neuroblastoma, prostate cancer, thyroid cancer, lung cancer, melanoma, and breast cancer. The harms of unnecessary diagnosis and cancer therapy call for a balanced presentation to people considering undergoing screening, even with a test of accepted benefit, with a goal of informed decision-making. We also discuss proposed strategies to mitigate the adverse sequelae of overdiagnosis.

Fine Needle Aspiration Cytology vs. Core Needle Biopsy for Thyroid Nodules: A Prospective, Experimental Study Using Surgical Specimen

PURPOSE

To evaluate and compare the diagnostic outcomes of ultrasonography (US)-guided fine needle aspiration (FNA) and core needle biopsy (CNB) performed on the same thyroid nodule using a surgical specimen for direct comparison.

MATERIALS AND METHODS

We included 89 thyroid nodules from 88 patients from February 2015 to January 2016. The inclusion criterion was thyroid nodules measuring ≥ 20 mm (mean size: 40.0 ± 15.3 mm). Immediately after surgical resection, FNA and subsequent CNB were performed on the surgical specimen under US guidance. FNA and CNB cytopathologic results on the specimen were compared with the surgical diagnosis.

RESULTS

Among the 89 nodules, 30 were malignant and 59 were benign. Significantly higher inconclusive rates were seen in FNA for malignant than benign nodules (80.0% vs. 39.0%, p < 0.001). For CNB, conclusive and inconclusive rates did not differ between benign and malignant nodules (p = 0.796). Higher inconclusive rates were seen for FNA among cancers regardless of US features, and in the subgroup of size ≥ 40 mm (62.5% vs. 22.9%, p = 0.028). Eleven cancers were diagnosed with CNB (36.7%, 11/30), while none was diagnosed using FNA.

CONCLUSION

In this experimental study using surgical specimens, CNB showed a potential to provide improved diagnostic sensitivity for thyroid cancer, especially when a conclusive diagnosis is limited with FNA.

Position paper from the Japan Thyroid Association task force on the management of low-risk papillary thyroid microcarcinoma (T1aN0M0) in adults

The incidence of thyroid carcinoma has been increasing worldwide. This is interpreted as an increase in the incidental detection of papillary thyroid microcarcinomas (PTMCs). However, mortality has not changed, suggesting overdiagnosis and overtreatment. Prospective clinical trials of active surveillance for low-risk PTMC (T1aN0M0) have been conducted in two Japanese institutions since the 1990s. Based on the favorable outcomes of these trials, active surveillance has been gradually adopted worldwide. A task force on the management of PTMC in adults organized by the Japan Thyroid Association therefore conducted a systematic review and has produced the present position paper based on the scientific evidence concerning active surveillance. This paper indicates evidence for the increased incidence of PTMC, favorable surgical outcomes for low-risk PTMC, recommended criteria for diagnosis using fine needle aspiration cytology, and evaluation of lymph node metastasis (LNM), extrathyroidal extension (ETE) and distant metastasis. Active surveillance has also been reported with a low incidence of disease progression and no subsequent recurrence or adverse events on survival if conversion surgery was performed at a slightly advanced stage. Active surveillance is a safe and valid strategy for PTMC, because it might preserve physical quality of life and reduce 10-year medical costs. However, some points should be noted when performing active surveillance. Immediate surgery is needed for PTMC showing high-risk features, such as clinical LNM, ETE or distant metastasis. Active surveillance should be performed under an appropriate medical team and should be continued for life.

Risk Factors of Central Lymph Node Metastasis in Papillary Thyroid Microcarcinoma and the Value of Sentinel Lymph Node Biopsy

Objective: The present study aims to investigate the risk factors of central lymph node metastasis (CNM) in papillary thyroid microcarcinoma (PTMC) and evaluate the predictive value of sentinel lymph node biopsy (SLNB) during surgery.

Methods: The clinicopathological data of 179 patients with PTMC staging in cN0 and with SLNB performed were analyzed retrospectively. Positive sentinel lymph node ratio (PSLNR) and additional positive lymph node (APLN) were analyzed in cases with positive SLNB. The efficiency of SLNB was investigated. ROC curves were plotted to evaluate the predictive value of PSLNR for APLN.

Results: Cumulative maximum diameter of tumors (CMD) (P = 0.041) and capsule involvement (CI) (P = 0.014) were independent risk factors for central lymph node metastasis. The SLNB success rate was 97.28%, and the incidence of CNM was 31.28%. The sensitivity, specificity, false positive rate (FPR), false negative rate (FNR), positive predictive value (PPV), and negative predictive value (NPV) of SLNB to evaluate CNM and APLN were 82.14 vs. 61.54%, 100 vs. 80.39%, 0 vs. 19.61%, 17.86 vs. 38.46%, 100 vs. 34.78%, and 92.48 vs. 92.48%, respectively. For cases with positive SLNB, subgroup analysis was performed according to APLN. The PSLNRs of true and false positive groups were 0.4620 ± 0.1744 and 0.2425 ± 0.1355, respectively (P < 0.001). Analyzing the predictive value of PSLNR by the ROC curve, the optimal diagnostic cutoff point was 0.2917 [AUC = 0.861 (95% CI: 0.757, 0.966), P < 0.001], and the sensitivity, specificity, FPR, FNR, PPV, and NPV of PSLNR were 87.50, 73.33, 26.67, 12.50, 63.64, and 91.67%, respectively.

Conclusion: CMD and CI are independent risk factors for central lymph node metastasis in PTMC. SLNB has good predictive value for CNM. For cases with positive SLNB, PSLNR could be used to predict the presence of APLN, which may provide a theoretical basis for intraoperative lymph node dissection.

Papillary thyroid microcarcinoma with lung metastases: a case report and review of the literature

BACKGROUND

Distant metastasis from papillary thyroid microcarcinoma (PTMC) is rare. Here we report a case of PTMC with multiple lung metastases.

CASE PRESENTATION

A 64-year-old man presented to our hospital with abdominal pain. Computed tomography incidentally revealed multiple lung nodules. The lung tumor was histologically diagnosed as metastasis of papillary thyroid carcinoma (PTC) by core needle biopsy via thoracoscopy. The patient was referred to our department for further examination. Neck ultrasonography revealed a 0.9 cm hypoechoic nodule in the right lobe of the thyroid gland, which was diagnosed as PTC by fine-needle aspiration cytology. Subsequently, total thyroidectomy was performed, followed by radioiodine therapy. Iodine-131 (131-I) scintigraphy showed a strong accumulation in the lung metastasis. The patient presented no evidence of progression of lung metastasis for 25 months after the operation.

CONCLUSIONS

Lymph node metastasis or extraglandular extension has been reported in the few published cases of metastatic PTMC, including the present case, and the average age of these cases was 58.8 ± 12.0 years. Although active surveillance without surgical resection is expected to become a standard of care for PTMC, this case indicates that a subset of PTMC patients with risk factors may develop distant metastases. Hence, careful preoperative screening is required to avoid complications associated with completion thyroidectomy.

Clinicopathological Characteristics of Thyroid Cancer in a Saudi Academic Hospital

Background

The global incidence of thyroid cancer (TC) has increased significantly over the past decades. In Saudi Arabia, it is the third most common cancer among adults. This study aims to review the clinical and histopathological characteristics of TC in Saudi Arabia and analyze the size trend over the years.

Methods

We conducted a retrospective chart review of all differentiated and poorly differentiated TC patients following up at a tertiary care center in the Western region of Saudi Arabia. All patients 11 years and older, diagnosed between 2004 - 2018, and with sufficient histopathological data were included.

Follicular and poorly differentiated TC were categorized and tumor stage was allocated. We performed descriptive and size trend analysis.

Results

We had a total of 285 patients who qualified for inclusion. The mean age at diagnosis was 40.6 years, and 81.05% of patients were females. Papillary TC comprised 88.07% of these neoplasms, and most patients (89.12%) were at Stage I. Only papillary TC showed a gender difference in the age of the diagnosis. In men, the mean age at diagnosis of papillary TC was 46.98 ± 15.4 years, while in female patients, it was 39.02 ± 12.8 years (p-value = 0.0001).

We did not find a trend toward smaller tumours in the more recent years in comparison to the early years (r = -0.083, p-value = 0.168).

Conclusions

TC is diagnosed at a younger age and larger sizes in Saudi Arabia in comparison to other countries. A gender difference was only noted with papillary TC in regard to the age of diagnosis. There was no trend toward smaller sizes of TC over the years.

Thyroid Cancer Epidemiology in South Spain: a population-based time trend study

PURPOSE

Thyroid cancer (TC) is the most common malignant disease of the endocrine system. The aim of this study was to analyze incidence and mortality trends of TC (C73 according to ICD-O-3) in Granada (Southern Spain) during the period 1985-2013, by sex, age, and histological type.

METHODS

This is a population-based cross-sectional study. Incidence data were obtained from the population-based Cancer Registry of Granada. All newly diagnosed cases of thyroid cancer over the period 1985-2013 were included. Joinpoint regression analysis with age-standardized rates were used to estimate annual percentage change (APC), CI 95% and turning points in trends. Results are presented by sex, age group, and histological type.

RESULTS

During the study period there were 1265 diagnosed cases of TC in Granada (72.6% in women). Incidence trends significantly increased in both men (APC: + 5.4%) and women (APC: + 4.7%). The most common histological types in both sexes were papillary (74.8%) and follicular (16.8%). The incidence has increased during the study period mainly due to papillary carcinoma, which has increased annually around 6% in both sexes. TC mortality trend during this period decreased in men (APC: -0.3%) and women (APC: -2.3%).

CONCLUSION

Our data showed an increasing trend in incidence of thyroid cancer in Granada, especially in women between 55-64 years. Mortality showed a slight decrease trend during the study period in both sexes. Papillary carcinoma was the most common histological type, with an increase of the relative weight of papillary microcarcinomas. Our study is in accordance with the European and worldwide trends in thyroid cancer incidence and mortality and sex differences.

Inhibitory roles of miR‑9 on papillary thyroid cancer through targeting BRAF

MicroRNA‑9 (miR‑9) is reported to be underexpressed in papillary thyroid carcinoma (PTC) tissues; however, the molecular mechanisms underlying the implication of miR‑9 in PTC have yet to be elucidated. The present study aimed to explore the potential roles of miR‑9 in PTC. PTC tissue samples and paired non‑cancerous adjacent tissues were collected from 60 patients with PTC. The human TPC‑1 thyroid gland papillary carcinoma cell line was used to investigate the molecular mechanisms underlying the roles of miR‑9 in PTC. The levels of miR‑9 and its downstream target gene BRAF were detected through reverse transcription‑quantitative polymerase chain reaction. MTT assay and flow cytometry were performed to evaluate cell viability and apoptosis, respectively. A mouse xenograft tumor model was established to observe the effects of miR‑9 on thyroid gland tumorigenesis in vivo. The present study revealed that the expression of miR‑9 was significantly reduced in PTC tissues compared with paired normal tissues. In addition, miR‑9 upregulation suppressed the expression of BRAF in TPC‑1 cells in vitro. Luciferase reporter assay demonstrated that BRAF may be a direct target gene of miR‑9 in TPC‑1 cells. In addition, following transfection with miR‑9 mimics, the viability of TPC‑1 cells was suppressed and their apoptosis was enhanced; conversely, transfection with miR‑9 inhibitor exerted the opposite effects in vitro. miR‑9 overexpression or downregulation also affected in vivo PTC tumorigenesis in athymic mice. The present findings suggested that miR‑9 may suppress the viability of PTC cells and inhibit tumor growth through directly targeting the expression of BRAF in PTC.

Long-term cardiovascular morbidity and mortality in patients treated for differentiated thyroid cancer

OBJECTIVES

Thyroid hormone suppression therapy has been widely used in the treatment of thyroid cancer, but concerns have been raised about the cardiovascular risks of this treatment. The objective of this study was to evaluate long-term cardiovascular morbidity and mortality in patients treated for differentiated thyroid cancer (DTC) and to assess the effect of TSH suppression and radioiodine (RAI) treatment on the cardiovascular outcome.

DESIGN

Retrospective cohort study.

PATIENTS AND MEASUREMENTS

Patients (n = 901) treated for DTC between 1981 and 2002 at 2 Finnish University hospitals were compared with a randomly chosen reference group (n = 4485) matched for age, gender and the place of residence. Kaplan-Meier and Cox regression analyses were used to estimate the risk of morbidity or death due to different cardiovascular diseases (CVD) after the diagnosis of DTC.

RESULTS

Morbidity due to any CVD (hazard ratio [HR] 1.16, 95% confidence interval [CI] 1.05-1.28) and due to all arrhythmias (HR 1.25, CI 1.06-1.48) and atrial fibrillation (AF) (HR 1.29, CI 1.06-1.57) was more frequent in the DTC patients than in the controls. The increased cardiovascular morbidity was confined to patients with a mean TSH level below 0.1 mU/L (HR 1.27, CI 1.03-1.58) and to those treated with RAI (HR 1.18, CI 1.05-1.31). Cardiovascular mortality, however, was lower among the patients than the controls (HR 0.73, CI 0.58-0.92), due to a lower mortality from coronary artery disease.

CONCLUSIONS

Differentiated thyroid cancer patients have an increased CVD morbidity, which is mostly accountable to AF and to TSH suppression below 0.1 mU/L.

No considerable changes in papillary thyroid microcarcinoma characteristics over a 30-year time period

Background

The prevalence of papillary thyroid microcarcinoma (PTMC) is continuously increasing but its clinical significance and management is still debatable. The aim of this study was to investigate possible changes in the clinical presentation, tumor characteristics, treatment modalities and long-term outcome during the last three decades in patients with PTMC.

Methods

We studied 335 patients with PTMC who were followed up for at least 5 years, from 1982 to 2015, and treated in accordance with the current literature or guidelines at each time-period. Patients were classified according to year of diagnosis into two time periods, TP1 from 1982–2000 and TP2 from 2001–2010.

Results

The mean follow-up of the whole cohort was 10.6 ± 5.3 (median 9) years. No change was noted in the mean age at diagnosis or the female to male ratio during the two time periods. In regard to tumor characteristics, multifocality and non-encapsulated follicular variant of PTMC was more often present while classic PTMC was less common in patients in the TP2, compared to patients in the TP1 (p = 0.007, p < 0.001 and p = 0.043 respectively). The prevalence of incidental PTMC was high but similar in both time periods (84.6 vs 80 %, p = 0.286). The majority of patients in TP2 underwent a total or near total thyroidectomy compared to patients in TP1 (91.7 vs 80 %, p = 0.001). However, more patients underwent thyroidectomy for toxic multinodular disease and less for Graves’ disease during TP1 compared to patients in the TP2 (p = 0.02 and 0.043 respectively). A significant percentage of patients underwent adjuvant radioiodine ablation, yet no difference was found between the two time periods (73.8 vs 79.5 %, p = 0.228). The rate of persistence was very low and not significant (3.1 vs 6.6 %, p = 0.165), while disease recurrence was observed in only 2 (0.6 %) patients, one from each time period.

Conclusions

We did not observe any important changes regarding the clinical presentation or tumor characteristics of PTMCs during a 30-year period. With applied interventions a favorable course was confirmed in the majority of patients without differences in recurrence or persistence during the last three decades.

Histopathological patterns of thyroid disease in Al-Madinah region of Saudi Arabia

OBJECTIVES

This study aimed to characterize the histopathological pattern of thyroid lesions among Saudi patients and to highlight the age and gender variations of these lesions as base line data.

MATERIALS AND METHODS

We retrospectively analyzed the data from thyroid specimens received at the Department of Pathology, King Fahad Hospital, Madinah, Saudi Arabia from January 2006 to December 2013.

RESULTS

The 292 thyroidectomy specimens received during the study period came from 230 (78.8%) females and 62 (21.2%) males giving a female: male ratio of 3.7:1. Age of the patients ranged from 14 to 95 years with a mean age 39.7 years. Two hundred and eleven (72.3%) cases were found to be non-neoplastic and 81 (27.7%) cases were neoplastic. The non-neoplastic group included: colloid goiter, including both diffuse and nodular goiter (170 cases; 58.2%), nodular hyperplasia (28 cases; 9.6%), Hashimoto/chronic lymphocytic thyroiditis (12 cases; 4.1%), and Grave's disease (1 case; 0.3%). In neoplastic lesions, there were 7 benign tumors and 74 malignant tumors. Among the benign tumors, 5 were follicular adenomas and 2 were Hurthle cell adenomas. Papillary carcinoma was the commonest malignant tumor accounting for 87.8% of all thyroid malignancies, followed by lymphoma, follicular carcinoma and medullary carcinoma. The size of papillary carcinoma was more than 2 cm in 40 cases (76.9%).

CONCLUSIONS

Non-neoplastic thyroid lesions were more common than neoplastic ones. Colloid goiter was the most common lesion. Follicular adenoma was the commonest benign tumor and papillary carcinoma was the commonest malignant lesion. There appears to be a slightly increased trend of papillary carcinoma diagnosis, most being diagnosed at an advanced stage.

Recurrent thyroid cancers have more peritumoural lymphatic vasculature than nonrecurrent thyroid cancers

BACKGROUND

The goal of the study was to evaluate angiogenesis and lymphangiogenesis in differentiated thyroid cancer and recurrences.

METHODS

Twenty-seven patients with recurrent differentiated thyroid cancer (20 papillary and seven follicular thyroid carcinomas) and 24 nonrecurrent thyroid cancers were included in this study. Additionally, 24 thyroid adenomas were included as benign controls. All thyroid cancer recurrences were operatively managed, and local recurrences in cervical lymph nodes or cervical soft tissue were histologically confirmed. Altogether, a total of 108 samples were evaluated using CD31 and D2-40 immunohistochemical staining and microscopy.

RESULTS

As measured in primary tumours, the median density of CD31-positive vascular structures was 327 vessels (v)/mm(2) for recurrent cancers, 362 v/mm(2) for nonrecurrent cancers and 484 v/mm(2) for thyroid adenomas (P = 0·017). Among the subgroups, the lowest median vascular density of 316 v/mm(2) was found in recurrent papillary cancers and the highest vascular density of 604 v/mm(2) was observed in nonrecurrent follicular cancers (P = 0·018). The median density of D2-40-positive peritumoural lymphatic vessels was 101/mm(2) in recurrent cancers, 56·1/mm(2) in nonrecurrent cancers and 53·9/mm(2) for adenomas (P = 0·015). In the subgroups, peritumoural lymphatic vascular density was 102 v/mm(2) in recurrent papillary cancers and 56·0 v/mm(2) in nonrecurrent papillary cancers (P = 0·044).

CONCLUSIONS

Recurrent thyroid cancers expressed less intratumoural microvessels than thyroid adenomas. A high density of peritumoural lymphatic vessels was found in recurrent papillary cancers. High blood vessel density may be a marker for less aggressive tumours, while high peritumoural lymphatic vasculature is a marker for more aggressive and recurrence-prone tumours.

Co-occurrence of papillary thyroid carcinoma and mucosa-associated lymphoid tissue lymphoma in a patient with long-standing hashimoto thyroiditis

Papillary thyroid carcinoma (PTC) is a common affliction of the thyroid gland, accounting for 70% to 80% of all thyroid cancers, whereas mucosa-associated lymphoid tissue (MALT) lymphoma of the thyroid gland is uncommon. The simultaneous occurrence of both malignancies is extremely rare. We report the case of a patient with both PTC and MALT lymphoma in the setting of Hashimoto thyroiditis. An 81-year-old female patient was first admitted with goiter and hoarseness, which was attributed to an ultrasonographic thyroid nodule. Subsequent fine-needle aspirate, interpreted as suspicious of papillary thyroid cancer, prompted total thyroidectomy. MALT lymphoma was an incidental postsurgical finding, coexisting with PTC in the setting of Hashimoto thyroiditis. Although the development of MALT lymphoma is very rare, patients with longstanding Hashimoto thyroiditis should undergo careful surveillance for both malignancies.

A core needle biopsy provides more malignancy-specific results than fine-needle aspiration biopsy in thyroid nodules suspicious for malignancy

BACKGROUND AND AIMS

The most commonly used diagnostic method for the preoperative diagnosis of thyroid nodules is ultrasound-guided fine-needle aspiration biopsy (FNA), which often yields non-diagnostic or non-definitive results and seldom produces definite malignant diagnoses. To improve upon the malignancy-specific sensitivity, we tested core needle biopsies (CNBs) of thyroid lesions taken from surgical specimens.

MATERIAL AND METHODS

52 consecutive patients with malignant or malignant-suspicious thyroid nodules were referred to Tampere University Hospital between May 2010 and December 2011. Preoperative FNAs were categorised as follicular neoplasm (48%), suspicion for malignancy (46%) or malignancy (6%). Intraoperative FNA and CNB samples were acquired from surgical specimens removed during surgery. The results of the needle biopsies were compared with the final pathological diagnosis.

RESULTS

CNBs had a high definitive sensitivity for malignancy (61%, CI 41% to 78%) whereas the definitive sensitivity for malignancy of FNAs was significantly lower (22%, CI 10% to 42%). CNB was not beneficial in the diagnosis of follicular thyroid lesions. When all suspected follicular tumours were excluded, the definitive sensitivity of CNB rose to 70% (CI 48% to 86%).

CONCLUSIONS

CNB may be beneficial for the diagnosis of papillary thyroid carcinoma and other non-follicular thyroid lesions. CNB may be considered as an additional diagnostic procedure in cases with FNA suspicious for malignancy.