Assessment of the prognostic value and N1b changes of the eighth TNM/AJCC staging system for differentiated thyroid carcinoma
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The aim of this study was to evaluate the prognostic veracity for disease-specific survival (DSS) of the eighth edition of the American Joint Committee on Cancer/Union for International Cancer Control tumor-node-metastasis staging system (TNM-8) compared with the seventh edition (TNM-7) in a Chinese population of patients with differentiated thyroid carcinoma (DTC) and to evaluate the impact of N1b redefinition and reclassification on prediction of survival.
A total of 569 DTC patients who underwent thyroid surgery in two Chinese hospitals were included in analysis to assess the predictive accuracy and N1b changes of TNM-8. Data from the Surveillance, Epidemiology and End Results (SEER) program were applied to validate the findings on N1b changes of TNM-8. Unadjusted DSS was calculated using the Kaplan–Meier method. Multivariable Cox proportional hazards models were used to evaluate the association of stage and lymph node metastasis (LNM) status with survival. The proportion of variation explained (PVE), Akaike information criterion (AIC), and Bayesian information criterion (BIC) were evaluated to compare model performance.
When TNM-8 was applied, 39.7% of patients were downstaged relative to TMN-7. In comparison of TNM-7 and TMN-8, the PVE was 18.68% and 22.33%, the AIC was 704.22 and 680.50, and the BIC was 702.98 and 679.24, respectively. In 569 Chinese patients with DTC, levels I–V LNM was significantly related to poorer DSS compared with N0 and level VI LNM. Among patients aged ≥ 55 years, those with levels I–V and VII LNM had significantly worse DSS than those with N0 and Level VI LNM. In the SEER dataset, patients with levels I–V and VII LNM had significantly worse DSS compared with those with N0 and Level VI LNM, especially in older patients (age ≥ 55 years).
TNM-8 staged a significant number of Chinese patients into lower stages and improved the accuracy of predicting DSS compared with TNM-7. However, changes in lateral LNM definition and classification of TNM-8 have a significant prognostic implication for patients with DTC, especially older patients (≥ 55 years). Our data suggest that a modified TNM staging system would be more useful for predicting mortality and determining a proper treatment strategy in patients with DTC.
KeywordsTNM-7 TNM-8 N1b Prognostic value Differentiated thyroid carcinoma
This work was partially supported by grants from National Natural Science Foundation of China (Grant nos. 81472580, 81872169, 81702629).
Compliance with ethical standards
Conflict of interest
The authors declare no conflict of interest.
- 1.Haugen BR, Alexander EK, Bible KC et al (2016) 2015 American Thyroid Association Management guidelines for adult patients with thyroid nodules and differentiated thyroid cancer: the American Thyroid Association guidelines task force on thyroid nodules and differentiated thyroid cancer. Thyroid 26(1):1–133. https://doi.org/10.1089/thy.2015.0020 Google Scholar
- 4.Pontius LN, Oyekunle TO, Thomas SM et al (2017) Projecting survival in papillary thyroid cancer: a comparison of the seventh and eighth editions of the American Joint Commission on cancer/union for international cancer control staging systems in two contemporary national patient cohorts. Thyroid 27(11):1408–1416. https://doi.org/10.1089/thy.2017.0306 Google Scholar
- 5.van Velsen EFS, Stegenga MT, van Kemenade FJ et al (2018) Comparing the prognostic value of the eighth edition of the American Joint Committee on cancer/tumor node metastasis staging system between papillary and follicular thyroid cancer. Thyroid 28(8):976–981. https://doi.org/10.1089/thy.2018.0066 Google Scholar
- 8.Leboulleux S, Rubino C, Baudin E et al (2005) Prognostic factors for persistent or recurrent disease of papillary thyroid carcinoma with neck lymph node metastases and/or tumor extension beyond the thyroid capsule at initial diagnosis. J Clin Endocrinol Metab 90(10):5723–5729. https://doi.org/10.1210/jc.2005-0285 Google Scholar
- 9.Verburg FA, Mader U, Tanase K et al (2013) Life expectancy is reduced in differentiated thyroid cancer patients %3e/= 45 years old with extensive local tumor invasion, lateral lymph node, or distant metastases at diagnosis and normal in all other DTC patients. J Clin Endocrinol Metab 98(1):172–180. https://doi.org/10.1210/jc.2012-2458 Google Scholar
- 10.Kim HI, Kim K, Park SY et al (2018) Refining the eighth edition AJCC TNM classification and prognostic groups for papillary thyroid cancer with lateral nodal metastasis. Oral oncol 78:80–86. https://doi.org/10.1016/j.oraloncology.2018.01.021 Google Scholar
- 20.Beal SH, Chen SL, Schneider PD et al (2010) An evaluation of lymph node yield and lymph node ratio in well-differentiated thyroid carcinoma. Am Surg 76(1):28–32Google Scholar