PATTERNS OF NODAL AND DISTANT METASTASIS BASED ON HISTOLOGIC VARIETIES IN DIFFERENTIATED CARCINOMA OF THE THYROID

BACKGROUND: Understanding of differentiated carcinoma of the thyroid h as improved in recent years with the definition of prognostic factors and risk group analysis, We intend to review our experience of differe ntiated thyroid cancer in relation to the risk of nodal and distant me tastasis based on various histologic subgroups. METHODS: This is a ret rospective review of a consecutive series of 1,038 previously untreate d patients with differentiated carcinoma of the thyroid treated over a period of 55 years, Univariate and multivariate analysis of various p rognostic factors was performed, The incidence of nodal and distant me tastasis was analyzed based on various histologic varieties of differe ntiated thyroid cancer. RESULTS: There were 337 male and 701 female pa tients. The various histologic subgroups included papillary (810), fol licular (169), and Hurthle cell cancer (59). The cumulative risk of no dal metastasis based on histological group was 61%, 30%, and 21% for p apillary, follicular, and Hurthle cell variety, respectively, The risk of distant metastasis for the same histologic varieties was 10%, 22%, and 33%, respectively, The 5- and 20-year survival for these histolog ic subgroups was papillary (94% and 87%, respectively), follicular (87 % and 81%), and Hurthle cell tumors (81% and 65%; P <0.001). CONCLUSIO NS: The incidence of nodal metastasis is highest in the papillary subg roup; however, the incidence of distant metatasis was 33% in the Hurth le cell variety, The risk of nodal and distant metastasis varies consi derably based on individual histologic variety. (C) 1996 by Excerpta M edica, Inc.