WELL-DIFFERENTIATED THYROID CARCINOMAS - P53 MUTATION STATUS AND MICROVESSEL DENSITY

Background. Risk-stratification schemes exist for well-differentiated thyroid carcinoma and include prognostic factors such as age, sex, ext ent of tumor, size Of tumor, and presence of metastasis. Controversy c ontinues, however, over the aggressiveness of initial surgical interve ntion because of anecdotal experiences of poor clinical outcomes in lo w-risk patients. Our objective is to determine the prognostic signific ance of two biologic tumor markers, the p53 gene mutation and CD34 mic rovessel density (MVD) count, in well-differentiated tumors of thyroid gland. Methods. We selected 38 patients with well-differentiated thyr oid carcinomas from the University of Illinois Tumor Registry. Patient s had an ave-rage clinical follow-up of 10 years. Paraffin embedded tu mor specimens were available for all patients. Immunohistochemistry wa s performed to identify mutations of the p53 gene (Ab 1801) and to det ermine the MVD count (CD34). Results. There were significant increases in MVD counts within thyroid tumor tissue, when compared with surroun ding, normal thyroid tissue. There was no significant correlation note d, however, between increased MVD and histology or recurrence rates, T here was a trend toward higher MVD counts in tumor specimens of patien ts initially seen with metastatic lymphadenopathy. The incidence of p5 3 mutation expression was 28%, and there was no correlation between p5 3 status and histology, sex, recurrence rate, or survival, Conclusions . This study supports the concept of tumor neovascularization but fail s to correlate MVD with clinical behavior or pathologic features in we ll-differentiated thyroid carcinoma, Furthermore, we found that the p5 3 mutation status was not an independent prognosticator of tumor behav ior in these lesions. (C) 1998 John Wiley & Sons, Inc.