1.5-2 cm tumor size was not associated with distant metastasis and mortality in small thyroid cancer: A population-based study

Most guidelines for the diagnosis and management of thyroid nodules have suggested fine-needle aspiration as a diagnostic tool, with some of these previously published guidelines suggesting a cutoff size of 1.5 cm. In thyroid cancers (1-2 cm), we hypothesized that tumors 1.5 cm or larger had more unfavorable clinical outcomes than ones smaller than 1.5 cm nodules. Using the Surveillance, Epidemiology, and End Results database, we identified 14,117 patients diagnosed with only primary thyroid cancer between 1988 and 2007. After multivariable adjustment, we found that having a tumor 1.5 cm or larger in size was not associated with distant metastasis [adjusted odds ratio, 1.18; 95% confidence interval (CI), 0.95 to 1.48; P = 0.14] or the two causes of death (adjusted subdistributional hazard ratio (SDHR), 1.40; 95% CI, 0.96 to 2.04; P = 0.08 for thyroid cancer mortality; adjusted SDHR, 1.06; 95% CI, 0.88 to 1.27; P = 0.55 for noncancer mortality). Using a population-based cohort, in patients with primary thyroid cancer with a tumor size of 1.5-2 cm, there was no increased association with distant metastasis or probability of death, when compared with patients with primary thyroid cancer with a tumor size of 1.0-1.5 cm.