Association between Obesity and Tumor Size in Patients with Papillary Thyroid Cancer

Abstract

Purpose: Many observational studies have reported a correlation between obesity and increased risk of thyroid malignancy. However, the relationship of obesity with aggressive features in papillary thyroid cancer (PTC) is controversial. We aimed to investigate whether the clinicopathological features of PTC are associated with obesity. Methods: We reviewed the medical records of 210 PTC patients who were followed up over a period of 10 years and examined body mass index (BMI) and other biochemical and clinicopathological parameters. The relationships between BMI and these parameters were assessed by logistic regression models based on BMI quartile (Q). The mean follow-up duration was 135.6±14.8 (range, 120–151) months. Results: BMI had a strong positive correlation with age (r=0.208; P=0.002) and tumor size (r=0.177; P=0.01). We also found that patients with a higher BMI tended to be older (P=0.011) and have elevated triglyceride concentration (P=0.006), fasting plasma glucose (P<0.001), and thyroid-stimulating hormone (P=0.035). According to pair-wise comparisons of BMI, tumor size was remarkably higher in patients in Q4 (overweight and obese) than in patients in Q2 (normal weight) (P=0.01). In a multivariable-adjusted model, higher BMI was consistently significantly associated with larger tumor size (odds ratio, 1.433; 95% confidence interval, 1.097–2.053; P=0.041). However, there was no significant difference in long-term disease status, such as recurrence, persistent disease, and disease-free status, by BMI (P=0.781). Conclusion: Higher BMI (>26.4 kg/m2) was significantly correlated with larger tumor size, but not long-term disease status, in patients with PTC.