title: 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).
  
  
  CONCLUSIONS
  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.
authors.affiliation: Department of Nuclear Medicine, Shaukat Khanum Memorial Cancer Hospital and Research Centre, Lahore, Pakistan.
authors.forename: Aamna
authors.initials: A
authors.lastname: Hassan
authors.affiliation: Department of Nuclear Medicine, Shaukat Khanum Memorial Cancer Hospital and Research Centre, Lahore, Pakistan.
authors.forename: Madeeha
authors.initials: M
authors.lastname: Khalid
authors.affiliation: Department of Nuclear Medicine, Shaukat Khanum Memorial Cancer Hospital and Research Centre, Lahore, Pakistan.
authors.forename: Saima
authors.initials: S
authors.lastname: Riaz
authors.affiliation: Department of Nuclear Medicine, Shaukat Khanum Memorial Cancer Hospital and Research Centre, Lahore, Pakistan.
authors.forename: M Khalid
authors.initials: MK
authors.lastname: Nawaz
authors.affiliation: Department of Nuclear Medicine, Shaukat Khanum Memorial Cancer Hospital and Research Centre, Lahore, Pakistan.
authors.forename: Humayun
authors.initials: H
authors.lastname: Bashir
keywords: Follicular thyroid carcinoma; Radioactive iodine; Response evaluation; Risk assessment; Thyroidectomy
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