Poorly differentiated thyroid cancer in the context of the revised 2015 American Thyroid Association Guidelines and the Updated American Joint Committee on Cancer/Tumor-Node-Metastasis Staging System (eighth edition).

In PDTC patients, the updated AJCC/TNM staging system accurately predicts a high risk of death in stage III-IV, whereas it seems to be inadequate for predicting a very low or low risk of death expected for differentiated TC in stage I-II. The ATA initial HR may be also used to predict a high risk of PDTC-related death.