Immunohistochemical expression of p53 and bcl-2 proteins is not associated with sarcomatoid change in renal cell carcinoma.

An immunohistochemical study was conducted to examine the expression of p53 and bcl-2 proteins in RCC (renal cell carcinoma) with sarcomatoid change in order to determine whether abnormalities in those proteins are associated with an enhanced malignant potential of RCC. Paraffin-embedded tissues from 11 patients with RCC, in which sarcomatoid change was prominent, were stained using anti-p53, bcl-2 and Ki-67 antibodies. Immunoreactivities for these antibodies were compared between the sarcomatoid components and corresponding basic histologic (clear or papillary) components in individual cases. Measurement of the mean nuclear areas of each component was also performed using an image analyzer system. There was no substantial increase in immunoreactivity for p53 or bcl-2 proteins in sarcomatoid components as compared with basic components. In contrast, the percentage of Ki-67-positive cells and the mean nuclear area were significantly larger in sarcomatous components than in basic components. The expression of p53 and bcl-2 proteins was not likely to play a major role in the sarcomatoid change of RCC.