LYMPH-NODE METASTASIS OF DIFFERENTIATED T HYROID AND C-CELL CARCINOMAS - A METAANALYSIS OF PROGNOSTIC STUDIES

Surgical therapy of differentiated thyroid cancer (DTC) includes thyro idectomy plus central lymph node dissection and postoperativ radioiodi ne therapy. In cases of lymph node metastasis, T3/T4 tumors and C-cell -carcinoma (after thyroidectomy) uni- or bilateral modified radical ly mph node dissection of the neck (neck dissection) and of the mediastin um is recommended. The importance of lymph node metastasis for prognos is of survival in papillary, follicular and C-cell-carcinoma is discus sed controversial, however. Even the kind of surgical radicality is qu estioned. Thus a metaanalysis of 35 studies in 29 independent publicat ions from a pool of 2186 studies was performed. Univariate analysis de monstrates lymph node metastasis as a negativ prognostic factor in pap illary carcinoma with a 3.25/2.97, in follicular carcinoma with a 7.62 /4.0 and in C-cell-carcinoma with a 3.33/3.37 higher probability of mo rtality 5 and 10 years after operation. Modification of the present su rgical therapy can therefore only be accepted after univariate and mul tivariate analysis of all prognostic factors (age, sex, cell type, tum or extent, lymph node- and distant metastasis) and after it has proven superiority to the present strategy in prospective randomised trials.