Unanticipated prognosis of differential thyroid cancer patients with T0 stage: analysis of the SEER database 2004-2013

The prognosis of T0 stage differentiated thyroid cancer (DTC) remains unclear. This study aimed to investigate the prognosis of T0 stage DTC patients to provide a new perspective on treatment guidelines for these patients. We investigated a large cohort of DTC patients from the Surveillance, Epidemiology, and End Results (SEER) database between 2004 and 2013. Patient survival curves were examined by Kaplan-Meier analyses with log-rank tests and Cox proportional hazards regression analyses. In the study cohort, the rate of cancer-specific mortality per 1000 person-years for T0 was higher than T1–T3, but lower than T4. The all-cause mortality for T0 patients was higher than all other stages (T1–T4). Multivariate Cox regression modeling showed that T0 had a significant risk for cancer-specific mortality when compared to T1 and T4, but not T2 or T3, after adjustment for other risk factors. For all-cause mortality, T0 showed a significant risk for all-cause mortality when compared to T4, but not T1–T3 stage patients. Similar results were obtained after matching for influential factors using propensity scored matching analysis. The unanticipated prognosis of T0 stage DTC patients was found to be not better than of other stage DTC patients, providing new implications for the treatment of T0 stage DTC patients.