Study of immunohistochemical expression of insulin-like growth factor I and proliferating cell nuclear antigen in thyroid gland papillary carcinoma and its metastasis

Background. Several tumor factors are associated with papillary thyroid can cer. Most studies do not compare the expressions of these factors in the pr imary tumors and in their associated cervical metastasis. Methods. Paraffin sections of 20 patients with papillary carcinoma of the t hyroid gland with lymph node metastasis were studied. The presence and dist ribution of insulin-like growth factor I (IGF-I) and proliferating cell nuc lear antigen (PCNA) was analyzed, through immunohistochemical technique, in both primaries and lymph node metastasis. The results were correlated with clinical-pathologic data (sex, age, size of primary, multicentricity, thyr oid capsule invasion, lymphatic and blood vessels invasion, development of distant metastasis, and associated thyroid diseases). Results. The qualitative analysis showed the reaction for IGF-I was present in more than 90% of the neoplastic cells in both primaries and lymph node metastasis. No correlation with the clinical-pathlogical features was obser ved. Regarding the PCNA, the mean percentage of nuclei stained showed no st atistical difference between primaries and metastasis (p = 0.598). Except f or age, clinicopathologic data had no influence on the mean percentage of n uclei stained. A correlation was verified between the percentage of cells s tained by PCNA in primary tumors and the patients' age (p < 0.01). Conclusions. The expressions of these tumor factors are equally intense for both primary and metastatic tissue in papillary thyroid cancer. Despite th e small size of the sample, the expressions of ICE-I and PCNA could not be associated to clinical-pathologic features, except for the age. As patients over 40 years old had higher expression of PCNA, this marker may have prog nostic significance for patients with papillary thyroid cancer. (C) 1999 Jo hn Wiley & Sons, Inc. Head Neck 21: 723-727, 1999.