Endocrine practice : official journal of the American College of Endocrinology and the American Association of Clinical Endocrinologists 2017 11 16() doi 10.4158/EP-2017-0095
Clinical stage (cStage) in thyroid cancer determines extent of surgical therapy and completeness of resection. Pathologic stage (pStage) is an important determinant of outcome. The rate of discordance between clinical and pathologic stage in thyroid cancer is unknown.
The National Cancer Data Base (NCDB) was queried to identify 27,473 patients ≥45 years old with cStage I through IV differentiated thyroid cancer undergoing surgery from 2008-2012.
There were 16,286 (59.3%) cStage I patients; 4,825 (17.6%) cStage II; 4,329 (15.8%) cStage III; and 2,013 (7.3%) cStage IV patients. The upstage rate was 15.1% and the downstage rate was 4.6%. For cStage II there was a 25.5% upstage rate. The change in cStage was a result of inaccurate T-category in 40.8%, N-category in 36.3%, and both in 22.9%. On multivariate analysis the patients more likely to be upstaged had papillary histology, tumors 2.1-4 cm, total thyroidectomy, nodal surgery, positive margins, or multifocal disease. Upstaged patients received radioiodine more frequently (75.3% vs. 48.1%, p<0.001). CONCLUSION
Approximately 20% of cStage is discordant to pStage. Certain populations are at risk for inaccurate staging including cT2 and cN0 patients. Upstaged patients are more likely to receive radioactive iodine therapy.
cStage = clinical stage; pStage = pathologic stage; NCDB = National Cancer Data Base; DTC = differentiated thyroid cancer; ATA = American Thyroid Association; AJCC = American Joint Committee on Cancer; ICD-O-3 = International Classification of Diseases for Oncology, 3rd edition; RAI = radioactive iodine.