Clinical Behaviors Of Rare Variants Of Papillary Thyroid Carcinoma Are Associated With Survival

Objective: Among all subtypes of thyroid cancer,columnar cell variant(CCV)and encapsulated variant(ECV)are particularly rare subtypes that have not been exclusively studied.ECV was formally nominated in 2017 World Health Organization(WHO)of endocrine tumors.We through the following three aspects of research to explore the clinical characteristics of two kinds of pathological subtype.(1)To explore the clinical and pathological features of columnar and capsular subtypes of papillary thyroid carcinoma;(2)To explore the risk factors associated with survival rate of the two pathological subtypes;(3)To explore the local area of the columnar subtype Risk factors associated with lymph node metastasis and distant lymph node metastasis.Methods: This study consists of three parts.The SEER database(1988–2013)was used to compare characteristics of CCV and ECV with classic papillary thyroid carcinoma(PTC).Survival was analyzed by Kaplan–Meier method,log-rank test and Cox multivariate regression.Multivariate logistic regression was used to further analysis of lymph node metastases and distant metastases.Results: There were 765 CCV,529 ECV,and 39,035 PTC patients.Compared to PTC,ECV tended to be similar on OS,DSS,age,sex and distant metastases.But ECV has lower rate on tumor size>=20mm,thyroidectomy,Lymph nodes examination,extrathyroidal extension,and nodal metastasis(P <0.0001,respectively).Compared to PTC,CCV tended to be larger on average(26.40 mm vs.17.82 mm,p...