BRAF mutation in follicular variant of papillary thyroid carcinoma is associated with unfavourable clinicopathological characteristics and malignant features on ultrasonography

Core needle biopsy and ultrasonography are superior to fine needle aspiration in the management of follicular variant papillary thyroid carcinomas

PURPOSE

Follicular variant papillary thyroid carcinoma (FVPTC) is a problematic entity. FVPTCs are often misdiagnosed by the standard fine needle aspiration (FNA); in addition, FVPTCs represent a mixed group of tumors with two biologically distinct subtypes: The indolent encapsulated FVPTC and the aggressive infiltrative FVPTC. Recent changes in guidelines suggests that FVPTC management may be improved if subtypes can be determined preoperatively. Preoperative assays, FNA, core needle biopsy (CNB), and ultrasonography (US) were compared for their ability to identify and subtype FVPTCs to determine the most appropriate test to manage FVPTCs.

METHODS

The preoperative assays and clinicopathologic variables of 255 resected FVPTCs cases at Samsung Medical Center between 2012 and 2016 were retrospectively evaluated.

RESULTS

CNB had the overall best ability to manage FVPTCs with the highest rate of diagnosis indicating surgery, lowest rate of inconclusive results, high sensitivity (88.9%), specificity (87.7%), negative predictive value (97.0%), diagnostic odds ratio (DOR; 56.9), and excellent predictive ability (AUC 0.906) for differentiating FVPTC subtypes. US had a moderate DOR (12.8), good predictive ability (AUC 0.802), high sensitivity (75.0%) and specificity (81.0%). CNB and US both had significantly higher accuracy for discriminating FVPTC subtypes than FNA (AUC 0.908 and 0.877 > 0.671; p < 0.05). The excellent performance of CNB could be attributed to distinct histologic differences between FVPTC subtypes.

CONCLUSION

CNB and US had superior performance to FNA in the identification and subtyping of FVPTC. In institutions with skilled and experienced operators, CNB is the preferred method for evaluating possible FVPTC lesions.

Proteotypic Differences of Follicular-Patterned Thyroid Neoplasms

The diagnosis of follicular-patterned thyroid tumors such as follicular thyroid adenoma (FA), follicular thyroid carcinoma (FTC), and follicular variant of papillary thyroid carcinoma (FvPTC) remains challenging. This study aimed to explore the molecular differences among these three thyroid tumors by proteomic analysis. A pressure cycling technology (PCT)-data-independent acquisition (DIA) mass spectrometry workflow was employed to investigate protein alterations in 52 formalin-fixed paraffin-embedded (FFPE) specimens: 18 FA, 15 FTC, and 19 FvPTC specimens. Immunohistochemical (IHC) analysis of 101 FA, 67 FTC, and 65 FvPTC specimens and parallel reaction monitoring (PRM) analysis of 20 FA, 20 FTC, and 20 FvPTC specimens were performed to validate protein biomarkers. A total of 4107 proteins were quantified from 52 specimens. Pairwise comparisons identified 287 differentially regulated proteins between FTC and FA, and 303 between FvPTC and FA and 88 proteins were co-dysregulated in the two comparisons. However, only 23 discriminatory proteins between FTC and FvPTC were detected. Additionally, the quantitative results for ANXA1 expression based on IHC staining and PRM-MS quantification were consistent with the proteomic results, showing that ANXA1 can be used to distinguish FvPTC from FA and FTC. The differentially regulated proteins found in this study can differentiate FA from FvPTC. In addition, ANXA1 is a promising biomarker for differentiating FvPTC from the other thyroid tumors.

Prevalence of BRAFV600E mutation in Asian series of papillary thyroid carcinoma-a contemporary systematic review

Papillary thyroid carcinoma (PTC), the most common malignancy of the endocrine system, is frequently driven by BRAFV600E mutation, which was reported in 35-60% cases in Western series. Numerous studies have recently emerged from Asian countries and regions; however sufficient summary is lacking to date. BRAF mutation serves as a diagnostic and prognostic tool in thyroid cancer, therefore establishing a rate of BRAF on the national scale could be of practical significance. We performed systematic reviews of available literature to investigate the prevalence of BRAF mutation in series of PTC from various Asian countries and regions. Out of the total 3,966 reports identified via initial screening, 138 studies encompassing over 40,000 PTCs were included for the final analysis. A vast majority (90.2%) of PTCs with known BRAF status were from East Asia, including China, South Korea, and Japan, with BRAF mutation rates of 71.2%, 75.5%, and 70.6%, respectively. Less abundant Indian and Saudi Arabian series found 45.6% and 46.3% prevalence of BRAFV600E in PTC, respectively. Much limited evidence was available from Thailand, Iran, Kazakhstan, Taiwan, Singapore, Indonesia, Hong Kong, Philippines, Vietnam, Iraq, and Myanmar. No relevant publications were found from other highly populated countries, such as Pakistan, Bangladesh, and Malaysia. After grouping by geographic region, we found that the highest rate of BRAFV600E was reported in the PTC series from East Asia (76.4%). Much lower rate (45-48%) was seen in PTC cohorts from South Asia, Central Asia, and the Middle East while the Southeast Asian series were in between (57%). Further subgroup analysis revealed that studies employing fresh frozen tissue and fine-needle aspirates showed higher rates of BRAF compared to those used formalin-fixed paraffin-embedded tissues. We found that the PTC series enrolled patients' cohorts after 2010 demonstrated a higher rate of BRAF compared to the earlier series. Finally, pediatric PTCs had lower BRAF prevalence compared to the baseline rate for the country. In conclusion, despite considerable among and within countries heterogeneity, the Asian PTC series showed a higher prevalence of BRAFV600E mutation than that in Western series. Causes of geographic heterogeneity, whether genuine (etiology, genetics) or methodology-related should be further investigated.

Can Suspicious Ultrasound Features Predict BRAFV600E Status in Papillary Thyroid Cancer?

BACKGROUND

Papillary thyroid carcinoma (PTC) can be predicted from certain suspicious ultrasound (US) features of thyroid nodules. The aim of this study was to examine if these suspicious features can predict the more aggressive PTC associated with B-type Raf kinase (BRAFV600E) mutation.

METHODS

This was a retrospective review of prospectively collected data on patients with PTC and known BRAFV600E status. All patients underwent preoperative US by the same surgeon who performed all the operations. We divided patients into BRAFV600E positive and negative groups. All ultrasonographic data were collected including nodule size, echogenicity, solid or cystic nature, presence of calcifications, irregular margins, and internal vascularity.

RESULTS

Of 141 patients with PTC, BRAFV600E mutation was detected in 48 (34.0$) patients. There was no significant difference in nodule size (2.06 cm ± 1.37 vs. 2.15 cm ±1.55, p = 0.75) between BRAFV600E positive and negative groups. BRAFV600E positivity was associated with higher rates of -hypoechogenicity (57.5$ vs. 36.6, p = 0.02), calcifications (48.9 vs. 19.4$, p < 0.01), and irregular margins (21.3 vs. 6.5$, p < 0.01). There was no significant difference in the noncystic nature or internal vascularity between BRAFV600E positive and negative groups. The presence of all suspicious US features is associated with a positive predictive value of 100.0$. In the absence of all suspicious features, the negative predictive value was 84.2$. When suspicious lymph nodes (LNs) detected by preoperative US were compared, there was no significant difference between BRAFV600E positive and negative groups (30.6 vs. 21.7$, p = 0.35).

CONCLUSION

The presence of multiple suspicious US findings of thyroid nodules can predict the BRAFV600E mutation status of papillary thyroid cancer nodules. The highest accuracy overall (93.2$) was achieved by combining calcification, irregular margins, and hypoechogenicity with extrathyroidal extension and LN metastasis. Future multi-institutional studies are warranted to help surgeons with risk stratification and operative planning for patients with papillary thyroid cancer.

Prevalence of BRAFV600E Mutation in Follicular Variant of Papillary Thyroid Carcinoma and Non-Invasive Follicular Tumor with Papillary-Like Nuclear Features (NIFTP) in a BRAFV600E Prevalent Area

BACKGROUND

BRAF^V600E mutation status and prevalence of non-invasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) has not yet been reported in Korea. The aim of this study was to investigate the significance of the BRAF^V600E mutation in the follicular variant of papillary thyroid carcinoma (FVPTC) and to determine the prevalence of NIFTP in BRAF^V600E mutation-prevalent Korean patients.

METHODS

This study retrospectively analyzed 1,417 consecutive patients who underwent total thyroidectomy with routine prophylactic central lymph node dissection for papillary thyroid carcinoma (PTC). BRAF^V600E mutation analysis was performed routinely using multiplex polymerase chain reaction by applying dual priming oligonucleotide. Clinicopathological characteristics and ultrasonographic findings were compared between BRAF^V600E mutation-positive and -negative groups for FVPTC. Pathologists reviewed the pathology slides according to consensus diagnostic criteria for the encapsulated FVPTC and NIFTP.

RESULTS

The prevalence of the BRAF^V600E mutation in all subtypes of PTC was 61.0% (861/1,411). FVPTC presented a BRAF^V600E mutation rate of 27.3%. The FVPTC patients with BRAF^V600E mutation were older than those with no BRAF^V600E mutation (P = 0.021). The prevalence of NIFTP was 0.18% among all PTC patients (2/1,411) and the proportion of NIFTP among FVPTC was 9.1% (2/22).

CONCLUSION

The BRAF^V600E mutation is prevalent in Korean patients with FVPTC in a region with high frequency of the BRAF^V600E mutation and very low prevalence of NIFTP compared with that reported in western studies.

Clinical Characteristics of Subtypes of Follicular Variant Papillary Thyroid Carcinoma

BACKGROUND

Among follicular variant papillary thyroid carcinomas (FVPTCs), the noninvasive encapsulated subtype has an excellent prognosis. For this reason, reclassification of noninvasive encapsulated FVPTC (EFVPTC) as a new entity called "noninvasive follicular thyroid neoplasm with papillary-like nuclear features" (NIFTP) has been proposed, but controversy remains. To characterize noninvasive EFVPTC in an Asian population, the clinicopathologic features of each FVPTC subtype were compared in a Korean population.

METHODS

FVPTC patients (n = 142) who underwent thyroidectomy between 2009 and 2014, and whose tumor size was >1 cm, were included in the study. The surgical pathology of each patient was reevaluated by two independent expert pathologists.

RESULTS

The percentages of noninvasive and invasive EFVPTC and infiltrative FVPTC (IFVPTC) in the study were 30%, 31%, and 39%, respectively. There was no difference in preoperative cytological diagnosis or the extent of surgery between noninvasive and invasive EFVPTC. However, the proportion of Bethesda category IV was lower in IFVPTC (16%) than in noninvasive and invasive EFVPTC (35% and 36%, respectively). Therefore, thyroid lobectomy was more common in noninvasive or invasive EFVPTC (54% or 48%, respectively) than in IFVPTC (16%). Noninvasive EFVPTC showed lower multiplicity, extrathyroidal extension, and BRAF^V600E mutation frequency (three cases; 8%) than did invasive EFVPTC, but other pathological characteristics were similar. However, IFVPTC showed significant differences in tumor size, extrathyroidal extension, lymph node metastasis, Tumor Node Metastasis stage, and American Thyroid Association high-risk category compared with noninvasive and invasive EFVPTC. In the noninvasive EFVPTC group, there were six (14%) cases with multifocality and three (7%) cases with lymph node metastasis. However, only two cases with multifocality and one case with lymph node metastasis originated from noninvasive FVPTC, while the other cases were from coexisting conventional PTCs.

CONCLUSIONS

Noninvasive EFVPTC has favorable pathological features, but lymph node metastasis or BRAF^V600E mutations were observed in some patients. Therefore, in order for the distinction between noninvasive EFVPTC and invasive EFVPTC to have more clinical significance, the criteria for NIFTP need to be more strictly revised.

Role of Ultrasound in Predicting Tumor Invasiveness in Follicular Variant of Papillary Thyroid Carcinoma

BACKGROUND

Follicular variant of papillary thyroid carcinoma (FVPTC) is traditionally divided into infiltrative and encapsulated types. Adding to this classification, noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) represents a reclassification of a subset of cases (encapsulated tumors without lymphovascular or capsular invasion). The purpose of this study was to assess the role of ultrasound (US) in predicting tumor invasiveness in FVPTC.

METHODS

From January 2014 to May 2016, preoperative US examinations were performed on 151 patients with 152 FVPTCs who underwent surgery. Based on a pathologic analysis, the FVPTCs were categorized into three groups: NIFTP, invasive encapsulated FVPTC (iE-FVPTC), or infiltrative FVPTC (I-FVPTC). Each nodule was categorized based on the US pattern according to the Korean Thyroid Imaging Reporting and Data System (K-TIRADS) and the American Thyroid Association (ATA) guidelines. The correlation between tumor invasiveness and the K-TIRADS or ATA category was investigated using Spearman's rank correlation coefficient.

RESULTS

Among the 152 FVPTCs, there were 48 (31.6%) NIFTPs, 60 (39.5%) iE-FVPTCs, and 44 (28.9%) I-FVPTCs. US characteristics of the FVPTCs differed significantly according to tumor invasiveness (p ≤ 0.030). Tumor invasiveness showed a significant positive correlation with K-TIRADS (tumors of all sizes: r = 0.591, p < 0.001; tumors ≥1.0 cm: r = 0.427, p < 0.001) and ATA categories (tumors of all sizes: r = 0.532, p < 0.001; tumors ≥1.0 cm: r = 0.466, p < 0.001). According to both K-TIRADS and ATA guidelines for all-sized tumors, the most common subtype was NIFTP in low-suspicion nodules (52.6% and 51.6%), iE-FVPTC in intermediate-suspicion nodules (52.7% and 54.2%), and I-FVPTC in high-suspicion nodules (82.5% and 69.4%). After surgery, lymph node metastases were confirmed in two (4.2%) NIFTP cases, three (5.0%) iE-FVPTC cases, and eight (18.2%) I-FVPTC cases (p = 0.001). The results of the BRAF mutation analysis were not significantly different between the groups (p = 0.507).

CONCLUSIONS

Increasing tumor invasiveness from NIFTP to iE-FVPTC to I-FVPTC is positively correlated with the level of suspicion on US using both K-TIRADS and ATA guidelines.

Predictive Factors of Lymph Node Metastasis in Follicular Variant of Papillary Thyroid Carcinoma

BACKGROUND

Compared with conventional papillary thyroid carcinoma (PTC), follicular variant of PTC (FV-PTC) shows less aggressive behavior and better prognosis. Nonetheless, regional lymph node (LN) metastasis was found in 22.8% of FV-PTC patients. Because LN metastasis is a proven predictor of recurrence in PTC, it is important to assess LN metastasis in FV-PTC patients.

METHODS

We retrospectively reviewed 134 FV-PTC patients who underwent thyroidectomy with neck dissection.

RESULTS

Central LN metastasis (CLNM) and lateral LN metastasis (LLNM) were found in 50 (37.3%) and 16 (11.9%) patients, respectively. In the multivariate analysis for CLNM, male sex (adjusted OR 4.735, p = 0.001), nonencapsulated form (adjusted OR 2.863, p = 0.022), and tumor size >1.0 cm (adjusted OR 3.157, p = 0.008) were independent predictors of high prevalence of CLNM in FV-PTC patients. In the multivariate analysis for LLNM, microscopic extrathyroidal extension (ETE) (adjusted OR 3.939, p = 0.041) and CLNM (adjusted OR 13.340, p = 0.001) were independent predictors of high prevalence of LLNM in FV-PTC patients.

CONCLUSIONS

Meticulous perioperative evaluation and prophylactic central neck dissection may be beneficial for FV-PTC patients with male sex, nonencapsulated form, and tumor size >1.0 cm. Moreover, cautious perioperative evaluation of lateral neck LN may be mandatory for FV-PTC patients with microscopic ETE and CLNM.

Preoperative differentiation between noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) and non-NIFTP

BACKGROUND

A recent concept was proposed that the noninvasive encapsulated follicular variant of papillary thyroid carcinoma reclassified as "noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP)" is benign. Our aim was to identify the differences between NIFTP and non-NIFTP preoperatively.

METHODS

This retrospective study included a total of 208 patients with 208 follicular variant of papillary thyroid carcinomas (FVPTC) that were surgically confirmed at three university hospitals from 2008 to 2014. Clinical factors, the biopsy techniques and ultrasonography (US) imaging characteristics were compared between the NIFTP and non-NIFTP groups.

RESULTS

A total of 34 NIFTP (16·3%) and 174 non-NIFTP (83·7%) were observed. For NIFTPs, the need for surgery was indicated by ultrasonography-guided fine needle aspiration (US-FNA) in 54·3% and by ultrasonography-guided core needle biopsy (US-CNB) in 100% (P = 0·008). For non-NIFTP, no significant difference was noted in the rates of surgical indication between US-FNA and US-CNB (62·6% vs 78·9%, P = 0·054). The most common biopsy diagnosis of NIFTP was Bethesda category V (28·6%) in the US-FNA group and category IV (45·5%) in the US-CNB group. US diagnosis of NIFTP had a significantly lower rate of the high suspicion of malignancy than that of non-NIFTP (14·7% vs 37·9%, P = 0·024). Central nodal metastasis was found in only one case (2·9%) of NIFTP patients, but none had distance metastasis or recurrence.

CONCLUSION

Noninvasive follicular thyroid neoplasm with papillary-like nuclear features lacks malignant US features and is better triaged using US-CNB than using US-FNA to facilitate the surgical management. US evaluation is pivotal in determining the next step of FVPTC management.

Follicular variant of papillary thyroid carcinoma: comparison of ultrasound-guided core needle biopsy and ultrasound-guided fine needle aspiration in a multicentre study

OBJECTIVE

Pre-operative diagnosis of the follicular variant of papillary thyroid carcinoma (FVPTC) by ultrasound-guided fine needle aspiration (US-FNA) remains a challenge. The goal of this study was to investigate whether ultrasound-guided core needle biopsy (US-CNB) is superior to US-FNA in refining the surgical indications for the treatment of FVPTC.

DESIGN

This retrospective study enrolled 212 patients with 218 FVPTCs who were surgically confirmed at three university hospitals from January 2008 through December 2014. All patients underwent both or either US-FNA or US-CNB. FNA and CNB results were divided into identified surgical candidates or not based on the Bethesda system. Relevant clinical information and the rate of surgical candidates were compared between US-FNA and US-CNB groups.

RESULTS

Among 218 thyroid nodules, US-FNA was performed for 200 nodules and US-CNB for 51 nodules. Thirty-three nodules underwent both US-FNA and US-CNB. The rates of surgical candidates identified by US-FNA and US-CNB were 61·5% and 86·3%, respectively (P = 0·001). The rates of surgical candidates identified by repeat US-FNA and initial US-FNA with subsequent US-CNB were 53·9% and 78·8%, respectively (P = 0·042). A precise diagnosis of FVPTC was made in 1% of the patients in the US-FNA group and in 29·4% of the patients in the US-CNB group. The predominant US findings of FVPTCs included solid tumours (89·4%), wider-than-tall shape (82·6%), no calcifications (51·3%), hypoechogenicity (46·3%) and indeterminate diagnosis on US (50·5%).

CONCLUSIONS

In patients with FVPTC, US-CNB is a superior indicator for surgery compared to US-FNA. If a FVPTC is suspected but is initially indeterminate at FNA cytology, subsequent US-CNB should be considered instead of repeat US-FNA.

Follicular and Diffuse Sclerosing Variant Papillary Thyroid Carcinomas as Independent Predictive Factors of Loco-Regional Recurrence: A Comparison Study Using Propensity Score Matching

BACKGROUND

Only about half of papillary thyroid carcinoma (PTC) cases are classified as conventional PTC (CV-PTC), whereas various histologic variants constitute the remaining cases. Since controversies about the clinical behavior and outcomes of PTC variants continue, the purpose of this study was to compare the outcomes of patients with PTC variants who were treated at a large tertiary referral center in Korea.

METHODS

The medical records for 15,598 CV-PTCs, 435 follicular variants of PTC (FV-PTCs), and 66 diffuse sclerosing variants of PTC (DSV-PTCs) were retrospectively reviewed. Loco-regional recurrences (LRR) among PTC variants were compared using propensity score matching.

RESULTS

Analysis I compared CV-PTC with FV-PTC. After rigorous matching, 367 pairs were established. Recurrence-free survival (RFS) rates in CV-PTC were 96.1% at 5 years, 92.2% at 10 years, and 92.2% at 15 years, while those for FV-PTC were 98.8% at 5 years, 98.8% at 10 years, and 98.8% at 15 years (p = 0.026). Analysis II compared CV-PTC with DSV-PTC. Rigorous matching yielded 56 pairs. RFS rates for CV-PTC were 87.4% at 5 years, 87.4% at 10 years, and 87.4% at 15 years, while those for DSV-PTC were 68.9% at 5 years, 57.5% at 10 years, and were not available at 15 years (p = 0.013).

CONCLUSIONS

Compared with CV-PTC, FV-PTC showed less aggressive behaviors and more favorable outcomes. However, DSV-PTC showed more aggressive behaviors and a less favorable outcome than CV-PTC did. Therefore, the management strategy and follow-up plan for PTC should be differentiated according to the histologic variant.

Surgical safety and oncological completeness of robotic thyroidectomy for thyroid carcinoma larger than 2 cm

BACKGROUND

The safety of robotic thyroidectomy (RT) for small-sized thyroid carcinomas has been well established. The surgical outcomes of bilateral axillo-breast approach RT for thyroid carcinomas larger than 2 cm were evaluated and compared with those of open thyroidectomy (OT).

METHODS

The medical records of patients who underwent total thyroidectomy or hemithyroidectomy followed by completion thyroidectomy for differentiated thyroid carcinomas measuring 2-4 cm were retrospectively reviewed.

RESULTS

The study included 86 patients who underwent RT (n = 21) or OT (n = 65) with mean ages of 30.8 and 51.6 years, respectively. The mean tumor size was 2.8 cm in both groups. There were no significant differences between the RT and OT groups in vocal cord palsy rate (transient, 19.0 vs. 9.2 %; permanent, 0 vs. 1.5 %), postoperative hypoparathyroidism rate (transient, 19.0 vs. 33.8 %; permanent, 4.8 vs. 1.5 %), and the number of retrieved central lymph nodes in papillary thyroid carcinoma patients (6.4 ± 3.5 vs. 6.1 ± 3.9, respectively). The proportion of the patients with serum stimulated thyroglobulin level of <1.0 ng/ml at the initial radioactive iodine treatment was 64.7 % (11/17) for RT group and 66.0 % (35/53) for OT group (p = 0.920). There were three patients (1 RT and 2 OT) who had a biochemical incomplete response, and there was no case of anatomical recurrence or mortality during the median follow-up period of 40.2 months.

CONCLUSION

RT is a safe and oncologically sound treatment option for differentiated thyroid carcinomas measuring 2-4 cm in a selected group of patients. The role of RT should be evaluated in correlation with technological advances and increased experience.

Influence of body habitus on the surgical outcomes of bilateral axillo-breast approach robotic thyroidectomy in papillary thyroid carcinoma patients

Purpose

Obesity is associated with a number of medical comorbidities and is considered a risk factor for surgical complications. The purpose of this study was to analyze the influence of body habitus including obesity on the surgical outcomes of the Bilateral axillo-breast approach (BABA) robotic thyroidectomy (RoT) in papillary thyroid carcinoma (PTC) patients.

Methods

The medical records of 456 PTC patients who underwent BABA RoT between January 2011 and December 2012 were reviewed, and 310 women PTC patients who had undergone BABA robotic total thyroidectomy with central lymph node dissection were examined. Body habitus were evaluated by measuring body mass index (BMI), body surface area, and neck circumference. We divided the patients into BMI < 25 kg/m² and BMI ≥ 25 kg/m² groups. Clinicopathological data, surgical outcomes, and postoperative complications were evaluated.

Results

Clinicopathological characteristics did not differ between the 2 BMI groups. The creation of working space time (P = 0.210) and other surgical outcomes showed no significant differences between the groups. There were no statistically significant differences between body habitus indexes and postoperative length of hospital stay, number of retrieved central lymph nodes, postoperative thyroglobulin levels, occurrence of hypoparathyoidism, recurrent laryngeal nerve injury and wound complication.

Conclusion

Patient with large body habitus undergoing BABA RoT were not at an increased risk of surgical complications and showed good surgical outcomes. BABA RoT may be a good alternative operative method for PTC patients for whom cosmetic outcome is an important consideration.

Acute High-Dose and Chronic Lifetime Exposure to Alcohol Consumption and Differentiated Thyroid Cancer: T-CALOS Korea

Background

This study evaluated the effects of acute high-dose and chronic lifetime exposure to alcohol and exposure patterns on the development of differentiated thyroid cancer (DTC).

Methods

The Thyroid Cancer Longitudinal Study (T-CALOS) included 2,258 DTC patients (449 men and 1,809 women) and 22,580 healthy participants (4,490 men and 18,090 women) who were individually matched by age, gender, and enrollment year. In-person interviews were conducted with a structured questionnaire to obtain epidemiologic data. Clinicopathologic features of the patients were obtained by chart reviews. Odds ratios (ORs) and 95% confidence intervals (95%CI) were estimated using conditional regression models.

Results

While light or moderate drinking behavior was related to a reduced risk of DTC, acute heavy alcohol consumption (151 g or more per event or on a single occasion) was associated with increased risks in men (OR = 2.22, 95%CI = 1.27–3.87) and women (OR = 3.61, 95%CI = 1.52–8.58) compared with never-drinkers. The consumption of alcohol for 31 or more years was a significant risk factor for DTC for both men (31–40 years: OR = 1.58, 95%CI = 1.10–2.28; 41+ years: OR = 3.46, 95%CI = 2.06–5.80) and women (31–40 years: OR = 2.18, 95%CI = 1.62–2.92; 41+ years: OR = 2.71, 95%CI = 1.36–5.05) compared with never-drinkers. The consumption of a large amount of alcohol on a single occasion was also a significant risk factor, even after restricting DTC outcomes to tumor size, lymph node metastasis, extrathyroidal extension and TNM stage.

Conclusion

The findings of this study suggest that the threshold effects of acute high-dose alcohol consumption and long-term alcohol consumption are linked to an increased risk of DTC.

Factors associated with the sensitivity of fine-needle aspiration cytology for the diagnosis of follicular variant papillary thyroid carcinoma

BACKGROUND

The purpose of this study was to evaluate the factors associated with diagnostic accuracy of preoperative fine-needle aspiration (FNA) for follicular variant papillary thyroid carcinoma (FVPTC).

METHODS

The patients with FVPTC who underwent thyroidectomy were divided into 2 groups: "group A" (Bethesda category II, III, or IV) versus "group B" (category V or VI).

RESULTS

A total of 225 patients (117 in group A and 108 in group B) were included. Group B was associated with older age, malignant ultrasonographic features, smaller tumor size, extrathyroidal extension, higher stage, and B-type Raf (BRAF)(V600E) mutation compared with group A. In multivariable analysis, malignant ultrasonographic features and tumor size ≤3.0 cm were independent predictive factors for group B.

CONCLUSION

FVPTCs >3.0 cm are unlikely to be diagnosed as category V or VI. Clinicians should keep FVPTC in mind and consider diagnostic lobectomy for the nodules regardless of FNA or ultrasonographic findings. © 2015 Wiley Periodicals, Inc. Head Neck 38: E1467-E1471, 2016.

The follicular variant of papillary thyroid carcinoma: characteristics of preoperative ultrasonography and cytology

PURPOSE

The goal of this study was to validate the ultrasonography (US) and cytopathological features that are used in the diagnosis of the follicular variant of papillary thyroid carcinoma (FVPTC) and to characterize the role of BRAF (V600E) mutation analysis in the diagnosis of FVPTC.

METHODS

From May 2012 to February 2014, 40 thyroid nodules from 40 patients (mean age, 56.2 years; range, 26 to 81 years) diagnosed with FVPTC were included in this study. The US features of the nodules were analyzed and the nodules were classified as probably benign or suspicious for malignancy. Twenty-three thyroid nodules (57.5%) underwent BRAF (V600E) mutation analysis. Clinical information and histopathologic results were obtained by reviewing the medical records of the patients.

RESULTS

Thirty nodules (75.0%) were classified as suspicious for malignancy, while 10 (25.0%) were classified as probably benign. Seven of the eight nodules (87.5%) with atypia of undetermined significance/follicular lesion of undetermined significance (AUS/FLUS) cytology showed suspicious US features, while one of the two nodules (50.0%) with follicular neoplasm cytology presented suspicious US features. Five of the 23 nodules (21.7%) that underwent BRAF (V600E) mutation analysis had positive results, all of which were diagnosed as suspicious for malignancy or malignant based on cytology. None of the nodules with benign, AUS/FLUS, or follicular neoplasm cytology were positive for the BRAF (V600E) mutation.

CONCLUSION

US features allow nodules to be classified as suspicious for malignancy, and the presence of suspicious US features in nodules with ambiguous cytology may aid in the diagnosis of FVPTC. BRAF (V600E) mutation analysis is of limited value in the diagnosis of FVPTC.

Follicular variant of papillary thyroid carcinoma (FVPTC): histological features, BRAF V600E mutation, and lymph node status

PURPOSE

Follicular variant of papillary thyroid carcinoma (FVPTC) is currently treated like conventional papillary thyroid carcinoma (cPTC). Recent reports indicate that encapsulated FVPTC behaves like follicular adenomas, while infiltrative FVPTC behaves like cPTC. This raises the possibility that histology and/or mutation status might help personalize management of FVPTC regarding extent of surgery, intensity of follow-up, and targeted therapy. This study correlates histological features, immunoreactivity for CK19, HBME, and Gal, and BRAF V600E mutation with lymph node (LN) metastasis and follow-up in FVPTC.

METHODS

Forty-eight FVPTC (21 with regional lymph node metastasis [LN+] and 27 with negative lymph nodes [LN-]) were reviewed. Demographics, tumor focality, size, circumscription, follicular architecture, lymphovascular invasion, extrathyroidal extension (ETE), and margin status were charted. Macrodissected formalin-fixed paraffin-embedded sections from 47 (21 LN+ and 26 LN-) cases were analyzed for BRAF V600E (1799T>A) mutation using real-time PCR. Correlations between the variables and LN status were calculated.

RESULTS

Sixty-two percent of cases with ETE demonstrated LN metastasis, while 59 % of cases with circumscribed tumors were LN-. In multivariable analysis, ETE and tumor size ≥1 cm were the best predictors of LN+ status, whereas in cases without ETE, the infiltrative pattern and tumor size provided the "best fit." Immunostains and BRAF mutation status were not helpful. All four tumors that recurred were LN+, with infiltrative borders, and lacked the BRAF mutation.

CONCLUSIONS

Tumor circumscription, extrathyroidal extension, and tumor size ≥ 1.0 cm are predictors of lymph node status in FVPTC.

Follicular variant of papillary thyroid carcinoma with B-type Raf(V600E) showing higher frequency of suspicious sonographic features and multifocality

BACKGROUND

The purpose of this study was to investigate the correlation between B-type Raf (BRAF) kinase mutation and clinicopathological features of follicular variant of papillary thyroid carcinoma (PTC).

METHODS

Eighty-four patients with pathologically confirmed follicular variant of PTC, who underwent a preoperative BRAF(V600E) study, were analyzed. Clinicopathological parameters and ultrasonographic features were compared between the BRAF(V600E) -positive and negative groups.

RESULTS

A total of 41.7% of the patients showed BRAF(V600E) . The BRAF(V600E) -positive group showed the smaller tumor size (7.3 ± 3.6 mm vs 10.7 ± 8.9 mm; p = .018) and the more frequent multifocality (25.7% vs 8.2%; p = .028). Follicular variant of PTC with BRAF(V600E) showed suspicious ultrasonographic features (88.6% vs 57.1%; p = .002) more frequently. BRAF(V600E) positivity is associated with multifocality after adjusting for age, sex, the presence of suspicious ultrasonographic features, pathological tumor size, and thyrotropin level.

CONCLUSION

BRAF(V600E) was correlated with smaller tumor size and suspicious ultrasonographic features in follicular variant of PTC. BRAF(V600E) was a significant parameter for predicting multifocality of follicular variant of PTC.