Dynamic risk assessment in patients with differentiated thyroid cancer

Abstract

The stratification of patients with differentiated thyroid cancer based on their initial risk of recurrence, according to specific clinical, histopathological and perioperative data, is an important starting point for tailoring the follow-up during the first 1–2 years after initial therapy (surgery with or without radioiodine ablation). However, risk of recurrence re-stratification based on new clinical data that becomes available after considering the response to treatment (dynamic risk assessment) provides a more accurate prediction of the status at final follow-up and a more individualized approach. In this review, we summarized the available data regarding dynamic risk of recurrence and the suggested management of differentiated thyroid cancer patients according to the response to treatment. The use of this strategy is crucial to avoid overtreatment and intensive follow-up of the vast majority of patients who will have a very good prognosis and, on the other hand, focus therapeutic efforts on those patients who will have a worse prognosis. In the future, molecular biology analysis of the tumors and well-designed prospective studies will probably refine the risk of recurrence prediction.

Natural Course of the American Thyroid Association Response to Therapy Statuses (Dynamic Risk Stratification) in Differentiated Thyroid Cancer

“…The ATA and AJCC TNM staging systems are excellent tools to assess the risk of recurrence and mortality and their predictive power has been demonstrated in many studies from around the world [8,9,[14][15][16][17][18]. This is again demonstrated in this study from a Middle Eastern population (Table 2).…”

“…However, these staging systems are static systems that utilize clinicopathological features and radiological information available at the time of initial management and do not consider the possible changes in the clinical course over time and the additional biochemical and radiological data that become available during follow-up. This is where the concept of dynamic risk stratification was introduced which is based on the fact that the disease status may change over time, and the risk is a dynamic process that should be assessed at each visit [6,8,10,17]. Initially, dynamic risk stratification was suggested to be used during the first 2 years after the initial management [10].…”

How to identify indolent thyroid tumors unlikely to recur and cause cancer death immediately after surgery—Risk stratification of papillary thyroid carcinoma in young patients—

“…Most PTCs have a Ki-67 labeling index of ≤5% based on the author's experience (Table 1). It can be further confirmed with a dynamic risk assessment proposed by Tuttle et al and Rosario et al in patients who achieve an excellent response (absence of elevated serum thyroglobulin or structural disease detected by imaging tests) during clinical follow-up [41,65,66].…”

“…After the re-stratification based on the dynamic risk stratification system, among patients who had an initial excellent response, the probability of having structural incomplete response was reduced from 3 to 2% in ATA low-risk patients and from 18 to 2% in ATA intermediate risk patients by a thorough review by Pitoia and Jerkovich [41]. Their conclusion is in good agreement with our conclusion, that is integrating four clinical features, (young age, early-stage (T1-2 M0), curatively treated, and low Ki-67 labeling index of <5%), to identify very low-risk PTCs that are unlikely to recur, metastasize, or cause cancer death immediately after initial thyroid surgery.…”

Thyroid cancer in the Era of COVID-19

“…Patients with an excellent, indeterminate, or biochemical incomplete response to treatment do not constitute a risk group for COVID-19 infection, and the frequency of structural disease is less than 4%, 15%, and 20%, respectively [14]. Consequently, annual monitoring may be postponed for a further 6-8 months.…”