Follicular Thyroid Carcinoma: Disease Response Evaluation Using American Thyroid Association Risk Assessment Guidelines

Abstract

Objective: To evaluate the overall and progression-free survival for follicular thyroid carcinoma (FTC) based on the American Thyroid Association (ATA) staging system for recurrence risk assessment and the TNM staging system. Methods: A clinical review of FTC patients between 1995 and 2014 was conducted at a single center. The data was classified using the TNM staging system into low, intermediate, and high risk of recurrence as per the ATA risk assessment. Results: Over the course of 19 years, 114 (11.9%) of all of the thyroid cancer patients presenting to our hospital had FTC (i.e. 78 females and 36 males). The age range was 15-80 years. Ninety-four tumors were resectable and 18 were unresectable. Sixteen patients were excluded due to insufficient information on their recurrence risk. Based on the ATA categorization, 36 patients had a low recurrence risk. All patients were alive at the time of categorization, and 1 showed progressive disease. Thirty-eight patients had an intermediate recurrence risk. One patient died and 2 showed progression. Twenty-four had a high recurrence risk. Seven patients died and 6 showed progression. In terms of TNM stages, 2 (3.2%) stage I, 3 (17.6%) stage II, 1 (14%) stage III, and 2 (12.5%) stage IV patients died during follow-up. Both ATA risk classification and TNM staging were significant predictors of disease-free survival. On bivariate analysis, the ATA classification (HR 4.67; 95% CI 1.74-12.5, p = 0.002) was a better predictor of survival compared to the TNM classification (HR 1.26; 95% CI 0.98-1.62, p = 0.063). Conclusion: ATA risk stratification predicts the disease recurrence rate and survival better than TNM staging. Age does not have an association; the risk category with dynamic reassessment effectively better predicts the course of disease in FTC.

Survival Analysis of Papillary Thyroid Carcinoma in Relation to Stage and Recurrence Risk

“…We have also reported a similar trend for follicular thyroid cancer at our center. 6 The follicular variant of PTC did significantly better in terms of overall and disease-free survival compared with the classical variant. We did not have a large enough sample of the other variants to make a reliable comparison.…”

“…This is contrary to what we reported in follicular carcinoma thyroid, where age did not have a significant effect on the overall survival. 6 Over the recent years, we have been discharging low-risk patients from active follow-up if the initial 5 years show no biochemical or structural evidence of disease. This is in keeping with Garas et al 13 who after review of literature concluded that low-risk patients younger than 45 years of age with stage I disease show no survival benefit from lifelong follow-up after primary treatment and can be safely discharged to primary care.…”

Differentiated Thyroid Carcinoma: Distant Metastasis as an Unusual Sole Initial Manifestation

“…Distant metastasis at the time of initial presentation has a significant prognostic implication as the 10-year survival rate falls significantly to 50%. Factors including age, gender and distant metastasis are associated with survival outcomes in patients with WDTC ( 12 , 14 , 15 ). Metastasis to organs other than the bones and the lungs is not well understood and usually missed in clinical settings because of the rarity of such cases.…”

Can the American Thyroid Association Risk of Recurrence Predict Radioiodine Refractory Disease in Differentiated Thyroid Cancer?

“…Details of the overall survival of our DTC population have already been published [4,5]. In the present study, although 18 F-FDG PET/CT played an instrumental role in detecting sites of disease in RRD, there was no clear-cut prediction of the development of RRD using the TNM staging or ATA risk assessment systems.…”