Bryan Tran1,2, David Roshan1, Earl Abraham1, Laura Wang1, Natalia Garibotto1, James Wykes1,2, Peter Campbell1, Ardalan Ebrahimi1,2,3. 1. Department of Head and Neck Surgery, Liverpool Hospital, New South Wales, Australia. 2. Department of Medicine, University of New South Wales, New South Wales, Australia. 3. Australian School of Advanced Medicine, Macquarie University, Sydney, New South Wales, Sydney, Australia.
Abstract
Background: The American Joint Committee on Cancer (AJCC) removed microscopic extrathyroidal extension (ETE) from the 8th edition T staging for papillary thyroid cancer (PTC) based on increasing evidence that it is not an independent prognostic factor. Objectives: We compared the prognostic performance of AJCC 7th (pT7) and 8th (pT8) edition T stage systems, particularly in patients ≥55 years old without macroscopic ETE or distant metastases in whom T classification affects AJCC Tumor Node Metastasis (TNM) stage. Method: A retrospective analysis of disease-free survival (DFS) in 577 patients with PTC comparing pT8 vs pT7 using the Akaike information criterion (AIC), Harrell's C-index, and Proportion of Variation Explained (PVE). Results: Of 105 patients with AJCC7 T3 disease, 74 were down-staged. Overall, the prognostic performance of pT7 and pT8 was similar. However, in patients ≥55 years old without macroscopic ETE or distant metastases, pT8 was inferior to pT7 on the basis of higher AIC, lower C-index (0.67 vs 0.76), and lower PVE (30% vs 45%). In this subset, microscopic ETE was associated with multiple other adverse prognostic features and reduced DFS (hazard ratio, 2.8; 95% confidence interval, 1.5 to 5.2; P = 0.002), irrespective of tumor size. Discussion: In our cohort, pT8 was inferior to pT7 in patients ≥55 years old without macroscopic ETE or distant metastases in whom T classification affects TNM stage. Microscopic ETE was strongly associated with other adverse prognostic factors and reduced DFS in this patient subgroup and may be an effective surrogate for disease biology in PTC, irrespective of whether it is an independent prognostic factor.
Background: The American Joint Committee on Cancer (AJCC) removed microscopic extrathyroidal extension (ETE) from the 8th edition T staging for papillary thyroid cancer (PTC) based on increasing evidence that it is not an independent prognostic factor. Objectives: We compared the prognostic performance of AJCC 7th (pT7) and 8th (pT8) edition T stage systems, particularly in patients ≥55 years old without macroscopic ETE or distant metastases in whom T classification affects AJCC Tumor Node Metastasis (TNM) stage. Method: A retrospective analysis of disease-free survival (DFS) in 577 patients with PTC comparing pT8 vs pT7 using the Akaike information criterion (AIC), Harrell's C-index, and Proportion of Variation Explained (PVE). Results: Of 105 patients with AJCC7 T3 disease, 74 were down-staged. Overall, the prognostic performance of pT7 and pT8 was similar. However, in patients ≥55 years old without macroscopic ETE or distant metastases, pT8 was inferior to pT7 on the basis of higher AIC, lower C-index (0.67 vs 0.76), and lower PVE (30% vs 45%). In this subset, microscopic ETE was associated with multiple other adverse prognostic features and reduced DFS (hazard ratio, 2.8; 95% confidence interval, 1.5 to 5.2; P = 0.002), irrespective of tumor size. Discussion: In our cohort, pT8 was inferior to pT7 in patients ≥55 years old without macroscopic ETE or distant metastases in whom T classification affects TNM stage. Microscopic ETE was strongly associated with other adverse prognostic factors and reduced DFS in this patient subgroup and may be an effective surrogate for disease biology in PTC, irrespective of whether it is an independent prognostic factor.
Authors: Robert Seifert; Michael Andreas Schäfers; Barbara Heitplatz; Laura Kerschke; Burkhard Riemann; Benjamin Noto Journal: J Nucl Med Date: 2021-03-26 Impact factor: 11.082
Authors: Victoria Harries; Marlena McGill; Avery Yuan; Laura Y Wang; R Michael Tuttle; Ashok R Shaha; Jatin P Shah; Richard J Wong; Snehal G Patel; Ian Ganly Journal: Surgery Date: 2021-09-30 Impact factor: 4.348