There were 116 cases with large cell undifferentiated carcinoma in group A, 120 cases with small cell undifferentiated carcinoma in group B and 80 normal individuals from the same period in group C. The expression levels of TTF-1 and CD44v6 in the serum of group A, B and C and the cancer tissues and adjacent tissues of group A, B and C were detected using enzyme-linked immunosorbent assay (ELISA), and the levels in each group were compared.
The tumor recurrence showed a UC component (positive for cyclin D1 and p53; negative forTTF-1 and TG) with a residual HV of PTC (positive for cyclin D1, p53, TTF-1, and TG).
We evaluated the expression of TTF-1 in primary thyroid tissues (normal thyroid, papillary carcinoma and undifferentiated carcinoma) and in thyroid carcinoma cell lines using immunohistochemistry and RT-PCR.
Unexpectedly, TTF-1 expression was observed in almost all of the PTC and PDC cases and in half of the UDC cases; therefore, it was not useful to distinguish PDC from PTC or UDC.
Papillary carcinoma cells expressed TTF-1 mRNA in all but two cases, and its expression was also demonstrated in one of four undifferentiated carcinomas.