bcl2, p53 and bax in thyroid tumors and their relation to apoptosis

Twenty five thyroid tumors were investigated by immunohistochemistry for the presence of apoptosis, expression of p53, bax and bcl(2). In nine adenomas (average age 40) the rate of p53 positive cells was 5.7%, while it was 13.3% for bax and 41.7% for bcl(2) in the tumor cells. In six follicular carcinomas (average age 56) p53 positivity was obtained for 71.1%, while bax and bcl(2) positivity constituted 3.4 to and 2.5 to, respectively. In ten papillary adenocarcinomas (average age 42) p53 was positive in 39.6%, but bax and bcl(2) were positive in 3.4% and 3% of the tumor cells, respectively. Almost no signs of spontaneous apoptosis were found in any of the cases. Determination of p53, bax and bcl(2) ratio in thyroid tumors may contribute to the differentiation between follicular adenomas and carcinomas.