Relationship of body mass index with BRAF (V600E) mutation in papillary thyroid cancer

Association of Body Mass Index With Clinicopathological Features of Papillary Thyroid Carcinoma: A Retrospective Study

OBJECTIVE

We examined the effect of body mass index (BMI) on clinicopathological features of papillary thyroid carcinoma (PTC).

METHODS

The clinical data of 4476 patients with PTC who underwent surgical treatment were retrospectively analyzed. According to the different BMI of patients, it can be divided into underweight (BMI < 18.5 kg/m²), normal weight (18.5 ≤ BMI < 24.0 kg/m²), overweight (24 ≤ BMI < 28 kg/m²), and obese (BMI ≥ 28 kg/m²). Spearman correlation analysis was performed to assess the relationship between the BMI and the size of PTC tumor. Multivariate binary logistic regression analysis was performed to estimate the association of overweight and obesity with clinicopathological features of PTC.

RESULTS

There was a positive correlation between the BMI and PTC tumor size (r = 0.087, P < .001). As compared with normal weight patients with PTC, overweight and obese patients with PTC had a greater risk of bilaterality (odds ratio [OR] = 1.295, OR = 1.669), multifocality (OR = 1.273, OR = 1.617), extrathyroidal extension (OR = 1.560, OR = 2.477), T (3 + 4) stage (OR = 1.482, OR = 2.392), and recurrence risk (intermediate-high risk) (OR = 1.215, OR = 1.718) (P < .05 for all). As compared with normal weight patients with papillary thyroid microcarcinoma (PTMC), overweight and obese patients with PTMC had a greater risk of bilaterality (OR = 1.341, OR = 1.737), multifocality (OR = 1.244, OR = 1.640), extrathyroidal extension (OR = 1.992, OR = 2.080), T (3 + 4) stage (OR = 1898, OR = 2.039), and recurrence risk (intermediate-high risk) (OR = 1.458, OR = 1.536) (P < .05 for all).

CONCLUSION

Overweight and obesity were significantly associated with aggressive clinicopathological features of PTC and PTMC. The impact of overweight and obesity should be considered when choosing treatment decisions for PTC and PTMC.

Understanding the effect of obesity on papillary thyroid cancer: is there a need for tailored diagnostic and therapeutic management?

INTRODUCTION

Several studies have focused on the relationship between obesity and differentiated thyroid carcinoma (DTC), particularly papillary histotype (PTC). However, the association of obesity with both incidence and aggressiveness of PTC is still incompletely understood.

AREAS COVERED

We reviewed the mechanisms underlying the cross talk between obesity and thyroid carcinomas and described the most recent evidence evaluating the effect of obesity on the development of PTC, as well as the impact of excessive body weight on the clinicopathologic features and outcome of this type of cancer.

EXPERT OPINION

Available evidence suggests that excessive body weight is linked with a higher risk of getting PTC, while its impact on the aggressiveness of the disease, if present, is still not clear. Therefore, while attention should be paid to discover thyroid cancer in patients with obesity earlier, once diagnosed it should be managed following a conventional workup as in normal weight patients, based on the clinical presentation of the disease and including active surveillance if appropriate, as recommended by referral guidelines.

The Combined Utility of HBME-1 and Galectin-3 Immunohistochemistry and BRAF V600E Mutations in the Diagnosis of Papillary Thyroid Carcinoma

Newer diagnostic modalities have revolutionized the pathologist’s approach to diagnosing thyroid malignancies. Molecular characterization of these malignancies has helped circumvent common morphologic diagnostic difficulties by integrating their genotypic, phenotypic, and immunohistochemical features. BRAF V600E mutation has been characterized as highly specific for thyroid carcinoma, especially papillary thyroid carcinoma (PTC); human bone marrow endothelial marker-1 (HBME-1) and galectin-3 are also such markers that are highly specific for PTC. We propose to study HBME-1 and galectin-3 expression and BRAF V600E mutation in thyroid neoplasms and do a comparative analysis to determine whether there is a correlation between BRAF V600E expression and that of HBME-1 and galectin-3. We further propose to analyze the individual and combined diagnosed utility of the above-mentioned ancillary diagnostic techniques.

Influence of Nomenclature Changes on Trends in Papillary Thyroid Cancer Incidence in the United States, 2000 to 2017

CONTEXT

US papillary thyroid carcinoma (PTC) incidence recently declined for the first time in decades, for reasons that remain unclear.

OBJECTIVE

This work aims to evaluate PTC incidence trends, including by histologic subtype and size, and noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP).

DESIGN

This descriptive study uses US Surveillance, Epidemiology, and End Results-18 cancer registry data (2000-2017).

PATIENTS

Participants included individuals diagnosed with PTC (2000-2017) or NIFTP (2016-2017).

RESULTS

During 2000 to 2015, PTC incidence increased an average 7.3% per year, (95% CI, 6.9% to 7.8%) during 2000 to 2009, and 3.7% per year (95% CI, 0.2% to 7.3%) during 2009 to 2012, before stabilizing in 2012 to 2015 (annual percentage change [APC] = 1.4% per year, 95% CI, -1.8% to 4.7%) and declining in 2015 to 2017 (APC = -4.6% per year, 95% CI, -7.6% to -1.4%). The recent declines were observed for all sizes of PTC at diagnosis. Incidence of follicular variant of PTC (FVPTC) sharply declined in 2015 to 2017, overall (APC = -21.1% per year; 95% CI, -26.5% to -15.2%) and for all tumor sizes. Observed increases in encapsulated papillary carcinoma (classical PTC subtype) and NIFTP each accounted for 10% of the decline in FVPTC. Classical PTC incidence continuously increased (2000-2009, APC = 8.7% per year, 95% CI, 8.1% to 9.4%; 2009-2017, APC = 1.0% per year, 95% CI, 0.4% to 1.5%), overall and for all sizes except smaller than 1 cm, as did incidence of other PTC variants combined (2000-2017, APC = 5.9% per year, 95% CI, 4.0% to 7.9%).

CONCLUSION

The reasons underlying PTC incidence trends were multifactorial. Sharp declines in FVPTC incidence during 2015 to 2017 coincided with clinical practice and diagnostic coding changes, including reclassification of noninvasive encapsulated FVPTC from a malignant to in situ neoplasm (NIFTP). Observed increases in NIFTP accounted for 10% of the decline in FVPTC.

Obesity Is Associated with BRAFV600E-Mutated Thyroid Cancer

Background: Thyroid cancer incidence has increased in many parts of the world since the 1980s, as has the prevalence of obesity. Evidence suggests that people with greater body size have higher thyroid cancer risk. However, it is unclear whether this association is causal or is driven by over-diagnosis of indolent cancers, because overweight/obese people use health services more frequently than those of normal weight, thus conferring greater opportunity for incidental diagnosis. Assessing whether obesity is associated with higher-risk thyroid cancers might help clarify this issue. Methods: We recruited 1013 people diagnosed with thyroid cancer between 2013 and 2016 and 1057 population controls, frequency matched by sex and age group. We used logistic regression to assess the association between body mass index (BMI) and overall thyroid cancer risk as well as by tumor BRAF mutational status as a marker of potentially higher-risk cancer. Results: Overall, obesity was associated with greater risk of thyroid cancer (odds ratio [OR] = 1.72; 95% confidence interval [CI 1.37-2.16] for obese vs. normal BMI). The association with obesity was significantly stronger for BRAF-mutation positive than BRAF-negative papillary thyroid cancers (PTCs; OR = 1.71 [CI 1.17-2.50] for BRAF-positive vs. BRAF-negative cancers). The increased risks associated with overweight/obesity did not vary by histological subtypes or presence/absence of adverse tumor histologic features. Conclusions: Greater risk of BRAF-mutated PTCs among those with high BMI suggests that the association may not merely reflect greater health care service use and indicates an independent relationship between obesity and clinically important thyroid cancer.

Effect of MALAT1 Polymorphisms on Papillary Thyroid Cancer in a Chinese Population

Background: Long noncoding RNA MALAT1 has been previously reported in the carcinogenesis of several tumors, and its potential functional polymorphisms have also been investigated in various diseases. However, the relationship between these polymorphisms and the susceptibility of thyroid cancer has still been largely unknown. In the present study, we aimed to explore the association between MALAT1 polymorphisms and thyroid cancer (TC) susceptibility, as well as potential biological function in TC.

Methods: We conducted a case-control study with 1134 papillary thyroid cancer (PTC) patients and 1228 controls to evaluate the potential correlation between MALAT1 genetic variations (single nucleotide polymorphism, SNP) and the risk of PTC. More detailed molecular mechanisms were explored by luciferase assay, cell counting kit-8 (CCK-8), and flow cytometry.

Results: MALAT1 SNP rs619586 was identified as a significantly protective factor of PTC susceptibility (P = 0.017, OR= 0.76, 95%CI = 0.60-0.95). Further functional experiments of rs619586 indicated that G allele of rs619586 could significantly decrease MALAT1expression, reduce PTC proliferation, and directly increase PTC apoptosis.

Conclusions: Our findings suggested that MALAT1 SNP rs619586 could serve as a potential indicator for PTC susceptibility and pathogenesis.

Diagnostic significance of CK19, galectin-3, CD56, TPO and Ki67 expression and BRAF mutation in papillary thyroid carcinoma

The aim of the present study was to examine the rate of BRAF mutation and the expression profiles of CK19, galectin-3, CD56, thyroid peroxidase (TPO) and Ki67 in papillary thyroid carcinoma (PTC) and papillary thyroid micro-carcinoma (PTMC). A total of 246 cases of thyroid disease were collected, including PTC, PTMC, nodular goiter (NG) and Hashimoto thyroiditis (HT). The results revealed that CK19 expression was 116/120 in PTC, 61/64 in PTMC, 2/34 in NG and 1/28 in HT. Galectin-3 positive expression was 115/120 in PTC, 60/64 in PTMC, 6/34 in NG and 4/28 in HT. TPO positive expression was 8/120 in PTC, 1/64 in PTMC, 30/34 in NG and 25/28 in HT. CD56-positive expression was 12/120 in PTC, 3/64 in PTMC, 33/34 in NG and 26/28 in HT. Ki67 labeling index was 2.52±0.46% in PTC (120 cases), 2.62±0.52% in PTMC (64 cases), 2.55±0.44% in NG (34 cases) and 2.58±0.48% in HT (28 cases). BRAF mutation rate was 93/120 in PTC, 47/64 in PTMC, 3/34 in NG and 2/28 in HT. These results suggested that expression patterns of CK19, galectin-3, CD56 and TPO and BRAF mutation exhibit diagnosis value in thyroid disease. However, Ki67-positive rate exhibits no notable diagnosis value in thyroid disease.