Endocrine Abstracts

The discussion which prognostic factors are the most reliable to adequately assess the risk of cancer related death and relapse in differentiated thyroid cancers [DTC] is ongoing. To date, age at diagnosis and distant metastases were considered as the most important risk factors. Among other factors, that may influence both overall and disease free survival, were male sex, some histopathological features such as: tumor diameter, tumor grade, aggressive histotype, extrathyroidal extension, angioinvasion, and lymph node involvement. However, the results of different analyses, evaluating the role of any particular factor, are distinct. These divergent data were the reason leading to a significant change in the approach to DTC risk stratification. Currently, it is based on a continuous dynamic evaluation conducted through the whole follow-up, because a rigid risk assessment at DTC diagnosis does not reflect the real prognosis. The first evaluation, based according to the ATA criteria only on histopathological findings and TNM classification, stratifies a patient as low, intermediate or high risk. Next, during the further follow-up, the risk is re-stratified on the basis of the treatment outcomes (classified as one of the following categories: excellent response, incomplete biochemical response, incomplete structural response or indeterminate response). On the one hand, thanks to this re-stratification, patients demonstrating an excellent response to therapy have a minimal risk of DTC recurrence, regardless of an initial risk class. On the other hand, an incomplete response to initial therapy increases the probability of persistent disease or DTC recurrence. Thus, the new approach allows to avoid the over-treatment in subjects with an excellent response to the initial therapy and simultaneously to select patients requiring a more intensive monitoring due to a higher risk of DTC relapse.