P53 and Ki67 in Adrenocortical Tumors

Abstract

The p53 tumor-supressor gene has been reported as the most frequent genetic abnormality seen in human malignancies. Here we studied immunohistochemically the expression of p53 in a large series of adrenocortical tumors. The proliferative activity was assessed by the expression of Ki67. Tumor material consisted of 60 adrenocortical adenomas and 27 adrenocortical carcinomas. A tumor was scored as positive for p53 if more than 10% of the cells showed nuclear staining. All adrenocortical adenomas were negative for p53 and the percentage of Ki67 positive cells was mostly 1-2% but never exceeded 5%. Hormonal activity did not reflect the proliferation index. Adrenocortical carcinomas, however, behaved differently depending on hormonal activity. 10/13 of non-functional , 0/3 Conn's, 3/7 Cushing's and 3/4 virilizing carcinomas were positive for p53. The proliferative activity was also higher in non-fuctional carcinomas compared with hormonally active tumors. Our data show that majority of adrenocortical carcinomas are positive for p53, whereas all adenomas are negative. Hormonal activity of carcinomas reflects both p53 status and proliferation index. Thus, immunohistochemical levels of p53 and Ki67 are higher in hormonally inactive adrenocortical carcinomas.

A Case of Estrogen-secreting Adrenocortical Carcinoma with Subclinical Cushing's Syndrome

“…The criteria of Weiss have been extensively used to differentiate between benign and malignant adrenal tumors [12], and generally established as the only reliable method of discerning malignancy of the adrenocortical tumors. Immunohistochemical analyses of certain proliferation markers, such as p53 and Ki-67, have been demonstrated useful diagnostic markers for ACC: both proliferation indices are less than 10% in benign adrenal tumor, and correlates positively with malignant behavior in ACC [15,16]. High index greater 10% for both Ki67 and p53 in the present tumor indicates malignancy with its highly proliferative character.…”

Comparative diagnostic and prognostic performances of the hematoxylin-eosin and phospho-histone H3 mitotic count and Ki-67 index in adrenocortical carcinoma

“…Moreover, it has been also successfully applied in different neoplasms of the breast, [22][23][24][25][26] meninges, [27][28][29] brain, 30 lung, 31 soft tissues, [32][33][34] esophagus, 35 female genital tract, 36,37 prostate, 38 and urothelium, 39 as well as in cytology material from pancreatic endocrine tumors 40 and urothelial carcinoma. 41 The Ki-67 index represents an alternative method for assessing the proliferative potential in adrenocortical tumors and has already been shown to differentiate adrenocortical adenoma from carcinoma, [42][43][44][45][46][47][48][49] and to predict tumor behavior. 42,50,51 However, the use of the Ki-67 index is not officially incorporated in the diagnostic work up of adrenocortical carcinoma, which still largely relies on histomorphological parameters.…”

Clinicopathological features, biochemical and molecular markers in 5 patients with adrenocortical carcinoma

“…The Weiss's criteria on the basis of pathological characteristics are widely used for distinguishing malignant from benign adrenocortical tumors [6], while Ki-67 (MIB-1), a cell proliferative marker, and P53, a tumor suppressor gene product, are both used as diagnostic markers for ACC [7]. However, any biochemical and molecular markers most reliable for the diagnosis of ACC have not been fully identified yet.…”