p53 gene alterations in differentiated thyroid cancers

Analysis of 22 human thyroid cancers including papillary, follicular and medullary subtypes (PTC, FTC, MTC) by PCR-SSCP, and immunohistochemistry detected 4 deletions and 3 mutations. Deletions involved exons 1, 2-3 and 5-6 in 3 PTCs, mutations exons 2-3 in 2 MTCs and exons 8-9 in PTC4. p53 alterations occurred in 2/5 recurrent tumors and 2/3 tumors developing to cell lines. Immunohistochemistry detected p53 mutations in differentiated areas of papillary thyroid cancers as frequent events occurring at stage T1 to T4 in contrast to prior findings by other authors which restrict p53 alterations to undifferentiated stages.