<p>Obesity and Waist Circumference are Possible Risk Factors for Thyroid Cancer: Correlation with Different Ultrasonography Criteria</p>

Abstract

Background: Obesity has an important role in the pathogenesis of cancer; however, there are no clear mechanisms explaining the association between obesity and risk of thyroid cancer (TC). Methods: It is a cross-sectional study including 184 patients with benign thyroid nodules (BN) and 19 patients with TC. Body mass index (BMI), waist circumference (WC), hip circumference (HC), waist/hip (W/H) ratio were assessed and correlated to relevant clinico-pathological features of the patients, different ultra-sonographic (U/S) criteria and risk of malignancy. Results: There was a significant increase in BMI, WC and W/H ratio in TC patients compared to BN group (P=0.001, 0.011 and 0.003). Increased BMI, WC and HC were associated significantly with solid nodules (P<0.05). WC increased in hypoechoic (103.1 ±15.4cm) and heterogeneous (103.8±16.7cm) nodules, compared to isoechoic (97.3±15.5cm) and hyperechoic (96.1±10cm) nodules (P=0.046). It also increased with lymph nodes enlargement (P=0.04). There was a significant association between WC and TIRADS classification (P=0.032), as it increased with TR4b (118.5 ± 12.9 cm) and TR5 (117.3 ± 13.9 cm) compared to TR2 (114.1 ± 15.7 cm, P=0.025 and 0.008, respectively). WC is an independent predictor for TC [OR: 1.092, CI: 1.020-1.170, P=0.012]. It achieved sensitivity, specificity and AUC (71.4%, 68.7% and 0.750; respectively), at a cutoff value of 108.5 cm (P=0.003), and when combined with BMI at a cutoff value of 32.59 (77.8% and 68.4%, respectively, AUC: 0.780, P<0.001). Conclusion: Central adiposity is strongly associated with the risk of TC. WC is more superior to BMI when correlated with TIRADS classification and also is an independent predictor for TC.

Thyroid Nodules and Obesity

“…However, T2DM may be a risk factor for thyroid cancer independent of obesity [ 11 , 52 ]. A 5 kg/m 2 increase in BMI is correlated with a significant increase in the incidence of PTC [ 54 ]. Several studies have suggested a strong association between central adiposity and thyroid cancer [ 54 , 55 ].…”

“…A 5 kg/m 2 increase in BMI is correlated with a significant increase in the incidence of PTC [ 54 ]. Several studies have suggested a strong association between central adiposity and thyroid cancer [ 54 , 55 ]. Waist circumference is an independent predictor of thyroid cancer [ 54 ].…”

“…Several studies have suggested a strong association between central adiposity and thyroid cancer [ 54 , 55 ]. Waist circumference is an independent predictor of thyroid cancer [ 54 ]. An increase in BMI and waist-to-hip ratio also increases the risk of thyroid cancer.…”

The association of obesity with thyroid carcinoma risk

“…In addition to BMI, WC (109 cm or more) was considered a strong predictor of TC with a sensitivity of 77.8% and specificity of 68.4% in a cross‐sectional study 43 . WC is superior to BMI and reflects a specific index of abdominal adipose tissue distribution.…”