roidal spread and distant metastasis and histology (4—9).However, early markers able to predict patients with a low risk of suffering a poor outcome from those with a higher risk of suffering a poor

A retrospective immunohistochemical analysis ofthe adhesion molecule E-cadherin (E-CD) was performed in 112 differentiated thyroid carcino mm and 38 synchronous and 20 relapse metastases primarily from oper ations performed at the Medical School Hanover between 1982 and 1992. E-CD-speciflc antibody 5H9 was applied to paraffin-embedded tissues. All patients were clinically followed for a maximal period of 12 years. Lack of E-CD expression (i.e., <5% of tumor cells positive) occurred in 18 of 112 (16.1%)cases,whereasthe majorityshowedeitherlow (24.1%),medium (35.7%), or high (24.1%) positlvity. No difference was found between papillary (n = 88) and follicular (n = 24) carcinomas. Univariate statis tical analysis for survival (Kaplan-Meier) showed that lack of E-CD expression (P < 0.024) Is an adverse prognostic factor for differentiated thyroid carcinomas. The highest significance was seen among patients without lymph node involvement at first presentation (pN@P 0.0068) and among females (P = 0.0033). Multivariate analysis (Cox model) indicated that E-CD staining is an Independent prognostic factor (correct ed risk factor, 3.7; P < 0.03) in addition to distant metastasis (pMl) and tumor size. A comparison of E-CD stainings between prbnary tumors and their metastatic lesions showed similar results in both synchronous and relapse metastases after therapy. In conclusion, E-CD immunostaining is an independent prognostic indicator for differentiated thyroid carcino mas. It may help to uncover the small group ofpatients with differentiated thyroid carcinomas carrying a high risk of suffering an unfavorable clinical outcome.