Tissue Microarray Analysis of the Expression of p53, c-kit and CD34 in Sarcomas

ABSTRACT

BACKGROUND: Our objectives in this study were to (1) evaluate the possible role of p53, c-kit and CD34 proteins in sarcomas and to determine their potential relationship; (2) use a tissue microarray to compare the immunohistochemical staining results on both the tissue microarrays and the corresponding whole tissue sections. METHODS: Whole sections from 85 sarcomas were studied for the immunohistochemical expression of p53, c-kit and CD34. Tissue microarrays consisting of triplicate 2 mm cores from the corresponding blocks were constructed and stained according to the same protocols as those used for the whole sections. RESULTS: On whole section analysis, p53 protein was expressed in 25 cases (29.4%). Expression of c-kit was observed in 31 specimens (36.5%), whereas CD34 expression was noted in 11 tumors (12.9%). The overall concordance between triplicates was 96% (217/226). The consensus score from the combined triplicates agreed with the results on the whole sections at 91.4% (233/255). The correlations between p53 and CD34, and between c-kit and CD34, were statistically significant (p=.028 and p=.010 respectively). CONCLUSIONS: p53 and c-kit express relatively frequently in sarcomas. Tissue microarrays are an effective alternative to whole sections; however, the presence of triplicate punches seems to improve the yield but not the concordance of data.