Dynamic risk stratification in the follow-up of thyroid cancer: what is still to be discovered in 2017?

Abstract

The adequate risk stratification in thyroid carcinoma is crucial to avoid on one hand the overtreatment of low-risk and on the other hand the undertreatment of high-risk patients. The question how to properly assess the risk of relapse has been discussed during recent years and resulted in a substantial change in our approach to risk stratification in differentiated thyroid cancer, proposed by the newest ATA guidelines. First initial risk stratification, based on histopathological data is carried out just after primary surgery. It should be emphasized, that a high quality of histopathological report is crucial for proper risk stratification. Next, during the follow-up, patients are restratified considering their response to treatment applied and classified to one of the following categories: excellent response, biochemical incomplete response, structural incomplete or indeterminate response. This new approach is called dynamic risk stratification as, in contrary to the previous rigid evaluation performed at diagnosis, reflects a real-time prognosis and thereby substantially influences and personalizes disease management. In this review, we raise some unresolved questions, among them the lack of prospective studies, fulfilling evidence-based criteria, necessary to validate this model of risk stratification. We also provided some data concerning the use of dynamic risk stratification in medullary thyroid cancer, not yet reflected in ATA guidelines. In conclusion, dynamic risk stratification allows for better prediction of the risk of recurrence in thyroid carcinoma, what has been demonstrated in numerous retrospective analyses. However, the validation of this approach in prospective studies seems to be our task for near future.

Unexplained Hyperthyroglobulinemia in Differentiated Thyroid Cancer Patients as an Indication for Radioiodine Adjuvant Therapy: A Prospective Multicenter Study

“…These novel findings may play a vital role in elucidating the indication for RAT, facilitating nuclear medicine practice and interdisciplinary communications.Instead of the latest version, the original risk stratification protocol derived from 2009insufficient detailed data on lymph node involvement and molecular features, which have been additionally suggested by 2015 ATA guidelines. In addition, the risks were merely assessed before and soon post RAT, evading potentially replacement by response categorization, so-called dynamic risk stratification in some previous studies(13,14).As a result, up to 93.3% TT-DTC patients with unexplained postoperative hyperthyroglobulinemia were initially classified as ATA intermediate-high risk during the interval between surgery and RAT. Unexpectedly, the distributions of risk before and after RAT were similar, indicating a stable and intermediate-high risk-predominant stratification in this commonly encountered entity.…”

American Head and Neck Society Endocrine Section clinical consensus statement: North American quality statements and evidence‐based multidisciplinary workflow algorithms for the evaluation and management of thyroid nodules

“…The American Joint Committee on Cancer (AJCC) Staging and Dynamic Risk Stratification systems for DTC bring value when predicting disease mortality or recurrence, as well as for guiding decisions about treatment and surveillance. A substantial proportion of patients with DTC who are initially classified as intermediate and high risk have an excellent response to therapy and become low risk for developing recurrent disease . Initial risk estimates should be continually modified during ongoing follow‐up in a dynamic process of risk stratification.…”

“…A substantial proportion of patients with DTC who are initially classified as intermediate and high risk have an excellent response to therapy and become low risk for developing recurrent disease. 57 Initial risk estimates should be continually modified during ongoing follow-up in a dynamic process of risk stratification. The risk of cancer recurrence and disease-specific mortality may change over time as a function of a specific patients' clinical course and response to therapy.…”

Usefulness of dynamic risk stratification in pediatric patients with differentiated thyroid carcinoma

“…The DRS system classified pediatric patients into 4 groups, as shown in previous studies: excellent response, indeterminate response, biochemical incomplete response, and structural incomplete response [ 18 19 20 21 ]. The best response to the initial treatment was evaluated between 1 and 2 years after diagnosis of DTC with Tg level, TgAb level, and imaging findings.…”