Correlation between obesity and clinicopathological factors in patients with papillary thyroid cancer

Sex-dependent impact of obesity on aggressiveness of papillary thyroid cancer

PURPOSE

To investigate the impact of body mass index (BMI) on the aggressiveness of papillary thyroid cancer (PTC).

METHODS

A total of 1720 PTC patients with total thyroidectomy or lobectomy, from January 2017 to April 2020, were retrospectively evaluated. Based on BMI, they were divided into two groups, as follows: control (CON, < 24 kg/m2) and overweight and obesity (OB, ≥ 24 kg/m2), each sex being analyzed separately.

RESULTS

In the whole cohort, the OB group had significantly higher rates of extrathyroidal extension (21.5 vs. 16.8%, p = 0.013), multifocality (43.2 vs. 37.7%, p = 0.018), and BRAF-V600E mutation (82.9 vs. 79.3%, p = 0.015) than the CON group. In males, the OB group had increased rates of tumor size over 1cm (54.4 vs. 42.7%, p = 0.008), extrathyroidal extension (24.9 vs. 12.4%, p = 0.001), and multifocality (42.7 vs. 33.5%, p = 0.038). The OB group had significantly higher adjusted odds ratios (ORs) of 1.63 (1.14-2.33, p = 0.008), 2.12 (1.26-3.57, p = 0.005), and 1.56 (1.07-2.29, p = 0.022) for tumor size over 1cm, extrathyroidal extension, and multifocality compared with CON. Additionally, overweight and obesity were analyzed alone and the rates of extrathyroidal extension (30/100, 30.0%, p = 0.001) and tumor size over 1cm (65/100, 65.0%, p = 0.001) were significantly higher in the obesity group than in the overweight and CON groups. The obesity group had robust higher adjusted ORs of 2.51(1.50-4.20, p < 0.001), 2.93 (1.50-5.73, p = 0.002) and 1.89 (1.11-3.22, p = 0.020) for tumor size over 1cm, extrathyroidal extension, and multifocality compared with CON.

CONCLUSIONS

Overweight and obesity were predominant independent risk factors for PTC aggressiveness in males. These data indicated that the therapeutic treatment should be based on risk stratification by BMI in males.

Drawing as a Way of Knowing: How a Mapping Model Assists Preoperative Evaluation of Patients with Thyroid Carcinoma

Background: Effective pre-surgical planning is crucial for achieving successful outcomes in endocrine surgery: it is essential to provide patients with a personalized plan to minimize operative and postoperative risks. Methods: Preoperative lymph node (LN) mapping is a structured high-resolution ultrasonography examination performed in the presence of two endocrinologists and the operating surgeon before intervention to produce a reliable "anatomical guide". Our aim was to propose a preoperative complete model that is non-invasive, avoids overdiagnosis of thyroid microcarcinomas, and reduces medical expenses. Results: The use of 'preoperative echography mapping' has been shown to be successful, particularly in patients with suspected or confirmed neoplastic malignancy. Regarding prognosis, positive outcomes have been observed both post-surgery and in terms of recurrence rates. We collected data on parameters such as biological sex, age, BMI, and results from cytologic tests performed with needle aspiration, and examined whether these parameters predict tumor malignancy or aggressiveness, calculated using a multivariate analysis (MVA). Conclusions: A standard multidisciplinary approach for evaluating neck lymph nodes pre-operation has proven to be an improved diagnostic and preoperative tool.

Potential impact of obesity on the aggressiveness of low- to intermediate-risk papillary thyroid carcinoma: results from a MASTER cohort study

PURPOSE

Obesity is associated with an increased risk of papillary thyroid carcinoma (PTC). Evidence of the impact of obesity on PTC aggressiveness is scarce. We aimed to evaluate the association between the body mass index (BMI) and the presence of aggressive features of low- to intermediate-risk PTC in a prospective cohort.

METHODS

We prospectively enrolled 1,032 patients with low- to intermediate-risk PTC who underwent lobectomy at 22 hospitals in Korea and divided into three groups according to BMI, as follows: normal/underweight ( < 23 kg/m2), overweight (23-24.9 kg/m2), and obese ( ≥ 25 kg/m2). Clinicopathological features of PTC at diagnosis were evaluated.

RESULTS

Obese patients had a higher rate of macro-PTC ( > 1 cm) and greater incidence of extra-thyroidal extension (ETE), vascular invasion, and intermediate-risk tumors than those not classified as obese. Increased BMI was positively associated with the incidence of macro-PTC, ETE, vascular invasion, and intermediate-risk category. After adjusting for age, sex, pathological features, metabolic syndrome, thyroid function test, and smoking habits, obesity was a risk factor for ETE (odds ratio [OR] = 1.7, 95% confidence interval [CI]: 1.2-2.5, p = 0.005) and intermediate-risk PTC (OR = 1.7, 95% CI: 1.1-2.5, p = 0.011) in women. The association between obesity and ETE was significant regardless of whether or not women had metabolic syndrome. There was no significant association between obesity and aggressive PTC features in men.

CONCLUSION

BMI at the time of thyroid cancer diagnosis may affect the aggressiveness of low- to intermediate-risk PTC, especially in women.

A Data-Driven Approach to Refine Predictions of Differentiated Thyroid Cancer Outcomes: A Prospective Multicenter Study

CONTEXT

The risk stratification of patients with differentiated thyroid cancer (DTC) is crucial in clinical decision making. The most widely accepted method to assess risk of recurrent/persistent disease is described in the 2015 American Thyroid Association (ATA) guidelines. However, recent research has focused on the inclusion of novel features or questioned the relevance of currently included features.

OBJECTIVE

To develop a comprehensive data-driven model to predict persistent/recurrent disease that can capture all available features and determine the weight of predictors.

METHODS

In a prospective cohort study, using the Italian Thyroid Cancer Observatory (ITCO) database (NCT04031339), we selected consecutive cases with DTC and at least early follow-up data (n = 4773; median follow-up 26 months; interquartile range, 12-46 months) at 40 Italian clinical centers. A decision tree was built to assign a risk index to each patient. The model allowed us to investigate the impact of different variables in risk prediction.

RESULTS

By ATA risk estimation, 2492 patients (52.2%) were classified as low, 1873 (39.2%) as intermediate, and 408 as high risk. The decision tree model outperformed the ATA risk stratification system: the sensitivity of high-risk classification for structural disease increased from 37% to 49%, and the negative predictive value for low-risk patients increased by 3%. Feature importance was estimated. Several variables not included in the ATA system significantly impacted the prediction of disease persistence/recurrence: age, body mass index, tumor size, sex, family history of thyroid cancer, surgical approach, presurgical cytology, and circumstances of the diagnosis.

CONCLUSION

Current risk stratification systems may be complemented by the inclusion of other variables in order to improve the prediction of treatment response. A complete dataset allows for more precise patient clustering.

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.

Association between metabolic syndrome and clinicopathological features of papillary thyroid cancer

BACKGROUND

Metabolic syndrome (MetS) was a risk factor for papillary thyroid cancer (PTC). Whether MetS impacts the aggressiveness of PTC is still unclear. We carried out this study to clarify this issue.

METHODS

We evaluated 745 consecutive PTC patients treated with surgery. Patients were divided into three groups based on their number of MetS components: patients without any MetS components, patients with 1-2 MetS components, and patients with 3-5 MetS components. The clinical features and histological aggressiveness of PTC at the time of diagnosis were evaluated.

RESULTS

A total of 745 patients were included in this study. And, 145 patients had three or more metabolic components and were diagnosed as MetS. MetS was a risk factor for larger tumors (OR = 2.29, 95% CI: 1.31-4.03), more lymph node metastasis (OR = 1.97, 95% CI: 1.11-3.51), and later clinical stage (OR = 7.92, 95% CI: 1.59-39.34) after correction for age, sex, and thyroid-stimulating hormone (TSH) level and body mass index (BMI).

CONCLUSION

In our hospital-based cohort study MetS was associated with the aggressiveness of PTC. This association was still significant after adjusting for age, sex, TSH, and BMI.

The relationship between lipotoxicity and risk of extrathyroidal extension in papillary thyroid microcarcinoma

OBJECTIVE

To explore the relationship between triglyceride (TG) levels and aggressive pathological characteristics in papillary thyroid microcarcinoma (PTMC) patients, especially the relationship between TG, BMI, age, and extrathyroidal extension (ETE).

METHODS

A retrospective analysis of 9663 patients with PTMC in a single center from 2010 to 2017 was included in this study. Binary logistic regression was used to analyze the relationship between serum TG and aggressive pathological characteristics of PTMC in different genders. Further analyzing the risk of high TG in different ages and BMI groups.

RESULTS

Even after adjustment for confounding factors, high TG is still a risk factor for ETE in women with PTMC, but not a risk factor for men. Compared with the group with lower than 0.90 mmol/L, when the TG level is higher than 1.93 mmol/L, the risk of ETE in women increased by about 1.35-fold. The remaining two variables (BMI, age) as risk factors for ETE are analyzed. In the normal BMI group, high TG is still a risk factor for ETE. The risk of ETE in women more than 55 years old is significantly increased by 1.96-fold (1.34-fold in less than 55 years).

CONCLUSION

High TG in women is positively correlated with the risk of ETE in PTMC. PTMC with high TG in elderly women (more than 55 years) has a higher risk of ETE. TG is a potential serological index for predicting the risk of ETE in women with normal BMI.

A meta-analysis of the influence of body mass index on the clinicopathologic progression of papillary thyroid carcinoma

BACKGROUND

Papillary thyroid carcinoma (PTC) incidence has been increasing worldwide. Obesity, that is, having a high body mass index, is associated with the incidence of several cancers including colon, breast, esophageal, and kidney cancer. However, the association between obesity and the clinical features of PTC is still unknown. This study aimed to determine the impact of obesity on the clinical features of PTC.

METHOD

A database search was conducted for articles published up to 2020 on obesity and clinical features of PTC. Data were extracted from articles that met the meta-analysis inclusion criteria.

RESULTS

A total of 11 retrospective cohorts and 11,729 patients were included. Obesity was associated with the following variables in PTC patients: older age (difference in means = 1.95, 95% confidence interval [CI] 0.16-3.74, P = .03), male sex (odds ratio [OR] = 3.13, 95%CI 2.24-4.38, P < .00001), tumor size ≥1 cm (OR = 1.34, 95%CI 1.11-1.61, P < .002), multifocality (OR = 1.54, 95%CI 1.27-1.88, P < .0001), extrathyroidal extension (OR = 1.78, 95%CI 1.22-2.59, P = .003) and advanced tumor, node, metastasis stage (OR = 1.68, 95%CI 1.44-1.96, P < .00001). Preoperative serum thyroid-stimulating hormone level (difference in means  = 0.09, 95%CI 0.35-0.52, P = .70), Vascular invasion (OR = 0.84, 95%CI 0.56-1.26, P = .41), lymph node metastasis (OR = 1.07, 95%CI 0.87-1.32, P = .50), distant metastasis (OR = 1.14, 95%CI 0.64-2.04, P = .66), and recurrence (OR = 1.45, 95%CI 0.97-2.15, P = .07) were not associated with obesity.

CONCLUSION

Obesity was associated with several poor clinicopathologic prognostic features: older age, male gender, tumor size ≥1 cm, extrathyroidal extension, multifocality, and advanced tumor/node/metastasis stage. However, thyroid-stimulating hormone level, vascular invasion, lymph node metastasis, distant metastasis, and recurrence were not associated with obesity in PTC.

Association of BMI with Clinicopathological Features of Papillary Thyroid Cancer: A Systematic Review and Meta-Analysis

BACKGROUND

Papillary thyroid cancer (PTC) is the most common subtype of thyroid cancer. The incidence of PTC is rising in tandem with an obesity epidemic. Associations have been demonstrated between increased body mass index (BMI) and worse oncological outcomes in a number of malignancies. However, research on this topic in PTC to date has been inconsistent, often due to limited data. This study aimed to measure the association between BMI and potentially adverse clinicopathological features of PTC.

METHODS

A meta-analysis of studies reporting outcomes after surgical treatment of PTC was performed. PubMed, Embase and the Cochrane Library were searched systematically to identify studies which provided data on BMI and clinicopathologic features of PTC. Relevant data were extracted and synthesis performed using adjusted odds ratios where available and crude values when not. Data were analysed by inverse variance using random and fixed effects models.

RESULTS

Data on 35,237 patients from 15 studies met the criteria for inclusion. Obesity was associated with larger tumour size (MD = 0.17 cm [0.05, 0.29]), increased rates of multifocality (OR = 1.41 [1.16, 1.70]), extrathyroidal extension (OR = 1.70 [1.39, 2.07]) and nodal spread (OR = 1.18 [1.07, 1.30]). Associations were more pronounced as BMI increased. There was no association between BMI and bilaterality, vascular invasion or metastatic spread.

CONCLUSION

Increased BMI is significantly associated with multiple potentially adverse features of PTC. The effect on long-term oncological outcomes requires further evaluation.

Association Between Aggressive Clinicopathologic Features of Papillary Thyroid Carcinoma and Body Mass Index: A Systematic Review and Meta-Analysis

BACKGROUND

The association between adiposity and papillary thyroid carcinoma (PTC) has been reported in several studies, but its association with aggressive clinicopathologic features is not well-recognized. Our aim is to systematically review the literature to identify whether adiposity, expressed through Body Mass Index (BMI), is related to aggressive clinicopathologic features such as tumor-node-metastasis (TNM) stage, extrathyroidal extension (ETE), lymph node (LN) metastasis and multifocality in patients with PTC.

METHODS

A systematic search for articles was performed using the PubMed, EBSCO, and Cochrane Library for all articles published in English until December 2020. Specific keywords such as "papillary thyroid carcinoma", "Body Mass Index", "clinicopathologic features" were used in the search strategy. Two independent reviewers screened all retrieved articles based on predefined inclusion and exclusion criteria. Meta-analysis was performed in the studies that reported crude and adjusted odds ratios (OR). The methodological quality was assessed using the Newcastle-Ottawa Scale.

RESULTS

A total of 11 retrospective cohort studies involving 26,196 participants included. Our findings showed that elevated BMI was significantly associated with ETE in both overweight (OR 1.26, 95% CI: 1.09-1.44) and obesity group (OR 1.45, 95% CI:1.26-1.64). Elevated BMI was also significantly associated with multifocality in overweight patients (OR 1.17, 95% CI:1.10-1.24) and obese patients (OR 1.45, 95% CI:1.29-1.62). Also, obesity was significantly associated with increased tumor size (OR 1.77, 95% CI:1.52-2.03) and with LN metastasis (OR 1.28, 95% CI: 1.12-1.44), whereas being overweight was significantly associated with advanced TNM stage (OR 1.55, 95% CI:1.27-1.83).

CONCLUSION

Our results provide strong evidence for the association between higher BMI and ETE, multifocality, and tumor size. Further studies with a larger number of participants are required to elucidate further the association of increased BMI with advanced TNM stage and LN metastasis.

Correlation between obesity and clinicopathological characteristics in patients with papillary thyroid cancer: a study of 1579 cases: a retrospective study

Objective

To explore the relationship between body mass index (BMI) and clinicopathological characteristics in patients with papillary thyroid carcinoma (PTC).

Methods

The clinical data of 1,579 patients with PTC, admitted to our hospital from May 2016 to March 2017, were retrospectively analyzed. According to the different BMI of patients, it can be divided into underweight recombination (BMI < 18.5 kg/m), normal body recombination (18.5 ≤ BMI < 24.0 kg/m²), overweight recombination (24.0 ≤ BMI < 28.0 kg/m²) and obesity group (BMI ≥ 28.0 kg/m²). The clinicopathological characteristics of PTC in patients with different BMIs group were compared.

Results

In our study, the risk for extrathyroidal extension (ETE), advanced T stage (T III/IV), and advanced tumor-node-metastasis stage (TNM III/IV) in the overweight group were higher, with OR (odds ratio) = 1.99(1.41-2.81), OR = 2.01(1.43-2.84), OR = 2.94(1.42-6.07), respectively, relative to the normal weight group. The risk for ETE and T III/IV stage in the obese group were higher, with OR = 1.82(1.23-2.71) and OR = 1.82(1.23-2.70), respectively, relative to the normal weight group.

Conclusion

BMI is associated with the invasiveness of PTC. There is a higher risk for ETE and TNM III/IV stage among patients with PTC in the overweight group and for ETE among patients with PTC in the obese group.

Influence of body mass index on the clinicopathological features of 13,995 papillary thyroid tumors

PURPOSE

This retrospective study aimed to assess the association between obesity, gender, and specific clinicopathological features in patients with papillary thyroid cancer (PTC) and whether diagnostic ultrasonography (US) is adversely affected by obesity in these patients.

MATERIALS AND METHODS

This study retrospectively analyzed 13,995 adult patients with PTC from a single medical center in China. Data stratification was performed to assess the association of obesity with US features and aggressive clinicopathological features in different models according to the World Health Organization Body Mass Index (WHO-BMI) and Chinese BMI classification (CN-BMI). The odds ratio (OR) of malignant US features and aggressive clinicopathological features was calculated from binary logistic regression models.

RESULTS

The BMI, obesity ratio, malignant US features, and aggressive pathological characteristics of males were significantly higher than those of females. After adjusting for confounding factors, the association of obesity with malignant US features and aggressive pathological characteristics was found to be sex-dependent. Next, obesity (WHO-BMI) was found to have an "interfering effect" on the US assessment of PTC (OR = 0.754, 95% CI 0.609-0.932, P = 0.009) in women. Among both sexes, obesity (WHO-BMI) increased the risk of tumor size (OR_male = 1.539 and OR_female = 1.521) and multifocality (OR_male = 1.659 and OR_female = 1.449). However, obesity did not increase the risk of capsular invasion or tumor staging in males. The above results are consistent with the CN-BMI. In addition, age was found to have an "interfering effect" on the US evaluation of malignant nodules in both sexes.

CONCLUSION

The results of our study confirm that higher BMI is significantly associated with aggressive clinicopathological features of PTC. Gender differences were present with obesity ratios and aggressive clinicopathological features being significantly higher in men.

Potential Impact of BMI on the Aggressiveness of Presentation and Clinical Outcome of Differentiated Thyroid Cancer

BACKGROUND

Obesity is a risk factor for several cancers, including differentiated thyroid cancer (DTC). Moreover, it has also been investigated as a potential risk factor for aggressiveness of DTC, but the data gathered so far are conflicting. The aim of our study was to evaluate the relationship between body mass index (BMI), aggressiveness of DTC at diagnosis, and clinical outcome.

METHODS

We evaluated 1058 consecutive DTC patients treated with total thyroidectomy and enrolled at the time of first radioactive iodine (131I) treatment. Patients were divided into 4 groups based on their BMI: underweight (< 18.5 kg/m2), normal weight (18.5-24.9 kg/m2), overweight (25-29.9 kg/m2), and obese (≥ 30 kg/m2). Histological aggressiveness of DTC at the time of diagnosis and clinical outcome according to 2015 American Thyroid Association (ATA) guidelines were evaluated.

RESULTS

No differences in histological features, ATA risk of recurrence, activity of 131I administered and prevalence of 131I avid metastatic disease after first131I treatment, have been demonstrated among the groups. Furthermore, at the end of follow up (median = 5.7 years), no differences were evident in the number of further treatments performed as well as in the clinical response.

CONCLUSIONS

In our study group of Caucasian subjects, we could not demonstrate any association between BMI and aggressiveness of DTC, neither at the time of diagnosis nor during follow-up. These data indicate that postsurgical assessment and therapeutic attitude for treatment and follow-up of DTC should be based on the class of risk applied to the general population, with no concern for BMI.

Association between subjective symptoms and obesity and postoperative recurrence in differentiated thyroid cancer: a matched-pair analysis

Several patients with thyroid cancer experience symptom distress after diagnosis and surgery. Data on the association between symptomatology and disease recurrence are limited. A retrospective review of a prospectively maintained database was performed, and 57 patients who had recurrence after operation of differentiated thyroid cancer were identified. Controlling for age, sex, surgery, and tumour stage, 114 patients without recurrent disease were selected by case-control matching. Subjective symptoms at follow-up visits were extracted from medical records and classified into three symptom clusters: pharyngolaryngeal, psychoneurological, and gastrointestinal. Compared to the control group, patients with recurrence had higher symptom totals in the pharyngolaryngeal (P < 0.001) and psychoneurological clusters (P = 0.005). Symptom score >3 yielded a sensitivity of 61.4% and a specificity of 80.7% to predict recurrence. Multivariate Cox regression analysis revealed that high symptom score (hazard ratio [HR] = 4.184), family history of thyroid cancer (HR = 2.463), and obesity (HR = 1.981) were independently associated with disease recurrence. Taken together, the likelihood of postoperative recurrence seemed to increase with high self-perceived symptom burden, family history, and obesity in patients with thyroid cancer. The results could be applied to the recurrence surveillance and symptomatic management of thyroid cancer post-operation.

Nutritional status and follicular-derived thyroid cancer: An update

The incidence of differentiated thyroid cancer has been increasing in the last decades all over the world. Such a steady growth cannot be entirely attributable to more intensive thyroid nodule screening and more sensitive diagnostic procedures. Several environmental factors have changed with sufficient rapidity in the same time frame and may represent credible candidates for this increase. They include modified iodine intake, lifestyle-associated risk factors, exposure to various toxic compounds, pollutants and xenobiotics, nutritional deficiencies, eating habits and comorbidities. Foremost, nutritional patterns have gained high interest as possible promoters and modifiable risk factors for thyroid cancer in recent years. The aim of this narrative review is to focus on the relationship between thyroid cancer and nutritional factors, dietary habits and obesity. Low iodine intake has been associated to increased risk of thyroid cancer, favoring the development of more aggressive histotypes. Moreover, correction of iodine deficiency can shift thyroid cancer subtypes toward less aggressive forms, without affecting the overall risk for cancer. Actually, evidence regarding the association between selenium and vitamin D deficiency and thyroid cancer is very limited, despite their well-known anti-cancer potentials, and the clinical usefulness of their supplementation is still uncertain in this setting. Albeit the relationship between single foods and thyroid cancer is difficult to examine, fish and iodine-rich foods, vegetables, and fruits might exert protective effects on thyroid cancer risk. Conversely, no clear association has been found for other foods to date. Lastly, a clear association between obesity and the risk of thyroid cancer, with more aggressive behavior, seems to emerge from most studies, likely involving variations in thyroid function and chronic inflammation mediated by cytokines, insulin, leptin and adiponectins. Although no definite association between dietary factors and thyroid cancer has been firmly established so far, some nutritional patterns, together with excessive weight, seem to play a relevant role in thyroid cancer carcinogenesis as well as in its severity and aggressiveness. These effects may play an additive role to the well-established one exerted by environmental carcinogens, such as pollutants and radiation exposure.

Association of obesity with the clinicopathological features of thyroid cancer in a large, operative population: A retrospective case-control study

We aimed to investigate the association between excess body mass index (BMI) and papillary thyroid cancer (PTC) in an operative population, and the impact of higher BMI on clinicopathological aggressiveness of PTC.Charts of 10,844 consecutive patients with thyroid nodules undergoing partial or total thyroidectomy between 1993 and 2015 were reviewed. Patients diagnosed with PTC were stratified in 4 groups: BMI < 18.5 (underweight), 18.5 ≤ BMI < 24 (normal-weight), 24 ≤ BMI < 28 (overweight) and BMI ≥ 28(obese). The impacts of high BMI on prevalence and clinicopathological parameters of PTC were retrospectively analyzed in both univariate and multivariate binary logistic regression analysis.For every 5-unit increase in body mass, the odds of risk-adjusted malignance increased by 36.6%. The individuals who were obese and overweight were associated with high risk of thyroid cancer [odds ratio (OR)= 1.982, P < .001; OR= 1.377, P < .001; respectively] compared to normal weight patients, and this positive association was found in both genders. Obesity was independent predictors for tumors larger than 1 cm (OR = 1.562, P < .001) and multifocality (OR = 1.616, P < .001). However, there was no difference in cervical lymph node (LN) metastasis among BMI groups. Crude analysis showed BMI was associated with advanced tumor-node-metastasis (TNM) stage (relative risk, approximately 1.23 per 5 BMI units, P < .001), but this association disappeared after adjusting for confounding factors.Obesity was significantly associated with the risk of PTC in a large, operative population. Higher BMI was significantly associated with larger tumor size and multifocal tumor.

Prediction of the Prognosis Based on Chromosomal Instability-Related DNA Methylation Patterns of ELOVL2 and UBAC2 in PTCs

Papillary thyroid carcinoma (PTC) is the most common malignant tumor of endocrine systems. Chromosomal instability (CIN) is crucial to the clinical prognoses of tumor patients. DNA methylation plays an important role in the regulation of gene expression and CIN. Based on PTC samples from The Cancer Genome Atlas database, we used multiple regression analyses to identify methylation patterns of CpG sites with the strongest correlation with gene expression. A total of 4,997 genes were obtained through combining the CpG sites, which were represented as featured DNA methylation patterns. In order to identify CIN-related epigenetic markers of PTC survival, we developed a method to characterize CIN based on DNA methylation patterns of genes using the Student’s t statistics. We found that 1,239 genes were highly associated with CIN. With the use of the log-rank test, univariate Cox regression analyses, and the Kaplan-Meier method, DNA methylation patterns of UBAC2 and ELOVL2, highly correlated with CIN, provided potential prognostic values for PTC. The higher these two genes, risk scores were correlated with worse PTC patient prognoses. Moreover, the ELOVL2 risk score was significantly different in the four stages of PTC, suggesting that it was related to the progress of PTC. The DNA methylation pattern associated with CIN may therefore be a good predictor of PTC survival.

The impact of BMI on clinical progress, response to treatment, and disease course in patients with differentiated thyroid cancer

Introduction

Obesity is a serious health problem worldwide, particularly in developed countries. It is a risk factor for many diseases, including thyroid cancer. The relationship between obesity and prognostic factors of thyroid cancer is unclear.

Aims

We sought to ascertain the relationship between body mass index (BMI) and clinicopathological features increasing the risk of poor clinical course, treatment response, and clinical outcome in patients with differentiated thyroid cancer (DTC).

Subjects & methods

The study included 1181 patients with DTC (88% women and 12% men) treated at a single center from 2000 to 2016. BMI before surgery and aggressive clinicopathological features, according to the American Thyroid Initial Risk stratification system, were analyzed. The relationship between BMI and initial risk, treatment response, and final status of the disease was evaluated, incorporating the revised 2015 American Thyroid Association guidelines and the 8^th edition of the American Joint Committee on Cancer/Tumor-Node-Metastasis (AJCC/TNM) staging system. Patients were stratified according to the World Health Organization classification of BMI. Statistical analysis was performed using univariate and multivariate logistic regression analysis.

Results

Median follow-up was 7.7 years (1–16 years). There were no significant associations between BMI and extrathyroidal extension (microscopic and gross), cervical lymph node metastasis, or distant metastasis in univariate and multivariate analyses. BMI did not affect initial risk, treatment response or disease outcome. Obesity was more prevalent in men (p = 0.035) and in patients ≥55 years old (p = 0.001). There was no statistically significant relationship between BMI and more advanced TNM stage in patients ≤55 years old (stage I vs. stage II) (p = 0.266) or in patients >55 years old (stage I–II vs. III–IV) (p = 0.877).

Conclusions

Obesity is not associated with more aggressive clinicopathological features of thyroid cancer. Obesity is not a risk factor for progression to more advanced stages of disease, nor is it a prognostic factor for poorer treatment response and clinical outcome.

Associations between body mass index and lymph node metastases of patients with papillary thyroid cancer: A retrospective study

Epidemiological studies suggest that obesity is a risk of thyroid cancer, especially papillary thyroid cancer (PTC). However, the associations of obesity and clinic-pathological features, especially the association of body mass index (BMI) and lymph node metastasis of thyroid cancer are unclear. Seven hundred ninety-six primary patients with PTC were enrolled in this retrospective cohort study. The relationships between BMI and clinic-pathological features of PTC were evaluated by logistic regression models based on the 5-point increase in BMI and BMI quartiles (underweight, normal weight, overweight, and obesity). The 5-point increase in BMI was strongly associated with extra-thyroidal invasion [odds ratio (OR) 2.201, P < 0.001], primary tumor size larger than 1 cm (OR 1.267, P = 0.027), advanced tumor node metastasis (TNM) staging (OR 1.479, P = 0.004), and multifocality (OR 1.31, P = 0.01) in multivariable-adjusted models. The relationships between BMI and lymph node metastasis of PTC were evaluated by Mann-Whitney U test. The mean number of positive central lymph nodes and lateral nodes were increased with the increase of BMI when BMI ≥18.5 kg/m. It was not shown in underweight group. The present study found that increased BMI was associated with the lymph node metastases (LNMs) of patients with PTC, and other invasive features, including large tumor size, extra-thyroidal invasion, advanced TNM staging, and multifocality. Further studies with long-term follow-up are needed to confirm this finding.

Pretreatment BMI Is Associated with Aggressive Clinicopathological Features of Papillary Thyroid Carcinoma: A Multicenter Study

OBJECTIVES

The aim of the present study was to analyze the association between pretreatment body mass index (BMI) and the aggressiveness of papillary thyroid carcinoma (PTC) along with its clinical outcomes in a Chinese population with BMI classification for Asians.

METHODS

A retrospective, observational study was conducted on patients from two teaching hospitals in China. 1622 classical PTC patients were categorized into four groups according to BMI.

RESULTS

We found that increased BMI was associated with extrathyroidal extension, multifocality, the presence of lymph node (LN) metastasis, and advancing TNM stage in PTC patients. Furthermore, compared to patients with normal weight, those in the overweight and obese group exhibited a significantly increased risk of extrathyroidal extension, multifocality, cervical LN metastasis, and advanced TNM stage. 40 and 37 patients experienced persistent and recurrent disease, respectively. No differences regarding persistent disease or recurrence were observed among the BMI groups.

CONCLUSION

A higher pretreatment BMI has been strongly associated with aggressive features of PTC according to the BMI classification for Asians. Obesity was not found to be associated with a greater risk of recurrence.

Annual Average Changes in Adult Obesity as a Risk Factor for Papillary Thyroid Cancer: A Large-Scale Case-Control Study

We evaluated the association between weight change in middle-aged adults and papillary thyroid cancer (PTC) based on a large-scale case-control study. Our study included data from 1551 PTC patients (19.3% men and 80.7% women) who underwent thyroidectomy at the 3 general hospitals in Korea and 15,510 individually matched control subjects. The subjects' weight history, epidemiologic information, and tumor characteristics confirmed after thyroidectomy were analyzed. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were determined for the annual average changes in weight and obesity indicators (body mass index (BMI), body surface area, and body fat percentage (BF%) in subjects since the age of 35 years. Subjects with a total weight gain ≥10 kg after age 35 years were more likely to have PTC (men, OR, 5.39, 95% CI, 3.88-7.49; women, OR, 3.36, 95% CI, 2.87-3.93) compared with subjects with a stable weight (loss or gain <5 kg). A marked increase in BMI since age 35 years (annual average change of BMI ≥0.3 kg/m/yr) was related to an elevated PTC risk, and the association was more pronounced for large-sized PTC risks (<1 cm, OR, 2.34, 95% CI, 1.92-2.85; ≥1 cm, OR, 4.00, 95% CI, 2.91-5.49, P heterogeneity = 0.005) compared with low PTC risks. Weight gain and annual increases in obesity indicators in middle-aged adults may increase the risk of developing PTC.

Prospective validation study of Cernea classification for predicting EMG alterations of the external branch of the superior laryngeal nerve

PURPOSES

Cernea classification is applied to describe the external branch of the superior laryngeal nerve (EBSLN). Using intraoperative neural monitoring we evaluated whether or not this classification is useful for predicting which EBSLN subtype has an increased risk of injury.

METHODS

An analysis of 400 EBSLN. The identification of EBSLN was achieved with both cricothyroid muscle twitch and the glottis evoked electromyography response. We defined S1 initial EBSLN stimulation at identification and S2 final nerve stimulation achieved in the most cranial aspect of the nerve exposed above the area of surgical dissection after superior artery ligation.

RESULTS

The mean S1 amplitude acquired was 259+/67 (180-421), 321 +/79 (192-391), 371 +/38 (200-551) μV, respectively, for type 1, 2A, 2B (p = 0.08). The S1 and S2 amplitudes were similar in type 1 (p = 0.3). The S1 and S2 determinations changed significantly in type 2A and 2B (p = 0.04 and 0.03). EBSLN which demonstrated a >25 % decreased amplitude in S2 increased significantly from Type 1 (4.9 %) to Type 2A (11.2 %) and 2B (18 %) (p = 0.01). None of type 1, 2.8 % type 2A and 3 % type 2B showed a loss of EBSLN conductivity. The latency determinations did not vary significantly for any parameter compared.

CONCLUSIONS

The Cernea classification was, therefore, found to predict the risk of EBSLN stress. We identified amplitude differences between S1 and S2 determinations in type 2A and 2B, thus confirming that surgical dissection in these subtypes is, therefore, extremely difficult to perform.