Endocrine Abstracts

Purpose: The primary aim of this study was to evaluate changes in the diameter and volume of thyroid cancer nodules identified using fine-needle aspiration biopsy (FNAB) or surgery, and to compare the changes in size between thyroid cancer nodules and benign nodules. The secondary aim was to analyze the risk factors associated with thyroid cancer nodule growth.

Methods: A total of 96 patients with 102 nodules were enrolled in the cancer group, and 98 patients with 101 nodules were included in the benign group. All patients underwent thyroid ultrasonography at least twice at ≥1-year intervals.

Results: The initial mean age, gender, thyroid-stimulating hormone (TSH) levels, thyroid autoantibody levels, number of FNABs, initial maximum diameter, and initial volume did not differ between the two groups. The mean follow up durations in the cancer group and benign group were 29.5±18.8 and 31.9±15.8 months (P=0.32), respectively. The maximum diameter change in nodule length per year was 0.40±1.00 mm in the cancer group and -0.07±0.77 mm in the benign group (P=<0.01). The volume change (in mL and percent) per year was increased significantly in the cancer group compared with the benign group (0.06±0.14 ml vs. 0.003±0.05 ml, respectively, P<0.01; 26.9±57.9% vs. 1.72±26.0% P=<0.01). The initial maximum diameter and initial volume were independent risk factors for thyroid cancer nodule growth in multiple regression analysis.

Conclusion: In conclusion, the present study suggested that thyroid cancer nodules progress rapidly compared with benign nodules, as exhibited by the ~30% volume increase per year. Initial nodule size was an independent risk factor for cancer nodule growth.