Obesity and Overweight Are Associated with Minimal Extrathyroidal Extension, Multifocality and Bilaterality of Papillary Thyroid Cancer

Analysis of Body Mass Index and Clinicopathological Factors in Patients with Papillary Thyroid Carcinoma

Objective

To analyze the correlation between body mass index (BMI) and clinicopathological factors of papillary thyroid cancer (PTC).

Methods

The clinical data of patients with PCT who were hospitalized in the Department of Thyroid Surgery of the Affiliated Hospital of Guizhou Medical University from March 2023 to September 2023 were retrospectively collected, including age, gender, height, weight, BMI, v-raf murine sarcoma viral oncogene homolog B (BRAF) gene mutation, tumor size, multifocus, Hashimoto's thyroiditis, lymph node metastasis and other clinicopathological factors. According to the World Health Organization (WHO) definition for Asian population, BMI≥25kg/m2 was obese group, 23≤BMI≤24.9kg/m2 was overweight group, 18.5≤BMI≤22.9kg/m2 was normal weight group, and BMI≤18.5kg/m2 was low weight group. The clinicopathological factors of overweight and obese patients with PTC were analyzed.

Results

A total of 164 PTC patients were included, with an average BMI of (24.44±3.57) kg/m2. Age of overweight and obese PTC patients (Z=1.978, p=0.083); Gender of overweight and obese PTC patients (χ2 value: 11.570, p=0.004); Tumor size in overweight and obese PTC patients (Z=0.894, p=0.411); BRAF gene mutation in overweight and obese PTC patients (χ2 value: 1.452, p =0.623); Multifocal lesions were found in overweight and obese patients (χ2 value: 1.653, p =0.201). Hashimoto's thyroiditis was found in overweight and obese PTC patients (χ2 value: 1.147, p=0.298). Overweight and obese patients with PTC had lymph node metastasis (χ2 value: 1.690, p =0.251).

Conclusion

Overweight and obesity in PTC patients are correlated with male, but not with age, tumor size, BRAF mutation, multifocality, Hashimoto's thyroiditis and lymph node metastasis.

Overweight as a biomarker for concomitant thyroid cancer in patients with Graves' disease

The incidence of concomitant thyroid cancer in Graves' disease varies and Graves' disease can make the diagnosis and management of thyroid nodules more challenging. Since the majority of Graves' disease patients primarily received non-surgical treatment, identifying biomarkers for concomitant thyroid cancer in patients with Graves' disease may facilitate planning the surgery. The aim of this study is to identify the biomarkers for concurrent thyroid cancer in Graves' disease patients and evaluate the impact of being overweight on cancer risk. This retrospective cohort study analyzed 122 patients with Graves' disease who underwent thyroid surgery at Seoul St. Mary's Hospital (Seoul, Korea) from May 2010 to December 2022. Body mass index (BMI), preoperative thyroid function test, and thyroid stimulating hormone receptor antibody (TR-Ab) were measured. Overweight was defined as a BMI of 25 kg/m² or higher according to the World Health Organization (WHO). Most patients (88.5%) underwent total or near-total thyroidectomy. Multivariate analysis revealed that patients who were overweight had a higher risk of malignancy (Odds ratios, 3.108; 95% confidence intervals, 1.196-8.831; p = 0.021). Lower gland weight and lower preoperative TR-Ab were also biomarkers for malignancy in Graves' disease. Overweight patients with Graves' disease had a higher risk of thyroid cancer than non-overweight patients. A comprehensive assessment of overweight patients with Graves' disease is imperative for identifying concomitant thyroid cancer.

Exploring the Link between BMI and Aggressive Histopathological Subtypes in Differentiated Thyroid Carcinoma-Insights from a Multicentre Retrospective Study

Obesity's role in thyroid cancer development is still debated, as well as its association with aggressive histopathological subtypes (AHSs). To clarify the link between Body Mass Index (BMI) and AHS of differentiated thyroid carcinoma (DTC), we evaluated patients who underwent thyroidectomy for DTC from 2020 to 2022 at four European referral centres for endocrine surgery. Based on BMI, patients were classified as normal-underweight, overweight, or obese. AHSs were defined according to 2022 WHO guidelines. Among 3868 patients included, 34.5% were overweight and 19.6% obese. Histological diagnoses were: 93.6% papillary (PTC), 4.8% follicular (FTC), and 1.6% Hürthle cell (HCC) thyroid carcinoma. Obese and overweight patients with PTC had a higher rate of AHSs (p = 0.03), bilateral, multifocal tumours (p = 0.014, 0.049), and larger nodal metastases (p = 0.017). In a multivariate analysis, BMI was an independent predictor of AHS of PTC, irrespective of gender (p = 0.028). In younger patients (<55 years old) with PTC > 1 cm, BMI predicted a higher ATA risk class (p = 0.036). Overweight and obese patients with FTC had larger tumours (p = 0.036). No difference was found in terms of AHS of FTC and HCC based on BMI category. Overweight and obese patients with PTC appear to be at an increased risk for AHS and aggressive clinico-pathological characteristics.

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.

Bilaterality as a Risk Factor for Recurrence in Papillary Thyroid Carcinoma

Previous studies suggested that the multifocality of papillary thyroid carcinoma (PTC) would increase the risk of recurrence; however, the impact of its bilaterality remains unclear. Between 2011 and 2018, 1258 patients with PTC underwent total thyroidectomy at Ewha University Medical Center. The 5-year recurrence-free survival rate was 95.7% in patients with bilateral PTC, while those with unilateral multifocal PTC and a unifocal tumor showed a 5-year event-free survival rate of 97.0% and 97.8%, respectively (p = 0.004). A multivariable Cox proportional hazards model indicated that bilaterality (HR 2.550, 95% CI 1.354-4.800), male sex (HR 2.010, 95% CI 1.007-4.013), and tumor size (HR 1.748, 95% CI 1.316-2.323) were associated with recurrence, although unilateral multifocality did not increase the risk of recurrence (HR 1.211, 95% CI 0.348-4.213). In conclusion, bilaterality was associated with aggressive features, including tumor size and microscopic ETE. Moreover, bilaterality was an independent predictor of recurrence in patients with PTC. Patients with bilateral PTC might require careful treatment and follow-up approaches.

Obesity and thyroid cancer risk

PURPOSE OF REVIEW

This review explores recent evidence assessing the relationship between obesity and thyroid cancer.

RECENT FINDINGS

Consistent evidence from observational studies suggests that obesity increases the risk of thyroid cancer. The relationship persists when alternative measures of adiposity are used, but the strength of association may vary according to the timing and duration of obesity and how obesity or other metabolic parameters are defined as exposures. Recent studies have reported an association between obesity and thyroid cancers that are larger or have adverse clinicopathologic features, including those with BRAF mutations, thus providing evidence that the association is relevant for clinically significant thyroid cancers. The underlying mechanism for the association remains uncertain but may be driven by disruption in adipokines and growth-signaling pathways.

SUMMARY

Obesity is associated with an increased risk of thyroid cancer, although further research is required to understand the biological mechanisms underpinning this relationship. Reducing the prevalence of obesity is predicted to lessen the future burden of thyroid cancer. However, the presence of obesity does not impact current recommendations for screening or management of 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.

Impact of Multifocality on the Recurrence of Papillary Thyroid Carcinoma

The incidence of thyroid cancer has dramatically increased over the last few decades, and up to 60% of patients have multifocal tumors. However, the prognostic impact of multifocality in patients with papillary thyroid carcinoma (PTC) remains unestablished and controversial. We evaluate whether multifocality can predict the recurrence of PTC. A total of 1249 patients who underwent total thyroidectomy for PTC at the Ewha Medical Center between March 2012 and December 2019 were reviewed. In this study, multifocality was found in 487 patients (39.0%) and the mean follow-up period was 5.5 ± 2.7 years. Multifocality was associated with high-risk features for recurrence, including extrathyroidal extension, lymph node metastasis, and margin involvement. After adjustment of those clinicopathological features, 10-year disease-free survival was 93.3% in patients with multifocal tumors, whereas those with unifocal disease showed 97.6% (p = 0.011). Multivariate Cox regression analysis indicated that male sex (HR 2.185, 95% CI 1.047–4.559), tumor size (HR 1.806, 95% CI 1.337–2.441), N1b LN metastasis (HR 3.603, 95% CI 1.207–10.757), and multifocality (HR 1.986, 95% CI 1.015–3.888) were independent predictors of recurrence. In conclusion, multifocality increased the risk of recurrence in patients with PTC. Patients with multifocal PTCs may need judicious treatment and follow-up approaches.