Altered expression of p53 and its regulated proteins in phyllodes tumours of the breast

p53 and c-kit (CD117) protein expression as prognostic indicators in breast phyllodes tumors: a tissue microarray study

“…In breast phyllodes tumors, the role of p53 has been fairly well investigated, 1,[16][17][18][19] with some authors suggesting a possible prognostic function, 16,18,19 while its predictive utility has not been validated by others. 1,17 It is stated that p53 immunohistochemical expression in stromal cells can be relied upon as an adjunctive tool in the diagnosis of malignancy in phyllodes tumors.…”

“…Interestingly, p53 immunohistochemical positivity was also noted in a proportion of luminal epithelial and myoepithelial cells in our series. Studies of p53 expression in phyllodes tumors have focused primarily on stromal cells, 14,[16][17][18]25 with observation of perithelial accentuation of stromal cell staining. 14, 18 Feakins et al 1 mentioned that the epithelial component in their cases usually stained negatively, while in another two reports, p53 reactivity was described in the breast epithelium in conjunction with stromal staining, 26,27 and it was postulated that dual expression of p53 protein in both the epithelium and stroma reflected the existence of an interaction between these components, 26 akin to the conclusion of Sawyer et al, 28 who believed that both epithelium and stroma of phyllodes tumors were participants in the neoplastic process.…”

“…While studies on p53 and c-kit have predominantly dealt with protein expression using immunohistochemistry, it will be useful to validate these findings at the molecular level in order to determine specific genetic abnormalities in the responsible genes. Sequencing of the p53 gene carried out by various authors has discovered mostly mutations, 16,24 although one study disclosed a wild-type gene sequence in a malignant phyllodes tumor. 32 Proliferative activity using Mib-1 and S-phase fraction, 19,27 microvessel density, 25 CD34 and factor XIIIa stromal positivity 33 are also believed to be potentially helpful in predicting phyllodes tumor behavior, although their clinical relevance remains to be further ratified.…”

“…1,[16][17][18][19] p53 expression has been described as being associated with malignant histological features, but does not appear to predict recurrent likelihood. 1,17 Recently, c-kit (CD117) expression was also observed in malignant phyllodes tumors, although its impact on recurrence was not addressed.…”

Immunohistochemical expression of heparan sulfate correlates with stromal cell proliferation in breast phyllodes tumors

“…18 Several biological molecules such as p53, MIB1, and CD34 have been demonstrated to be possible prognostic indicators in phyllodes tumors. 16,[20][21][22] As heparan sulfate has been shown to be differentially expressed in many forms of cancers including breast cancers, we aimed to investigate its relationship with malignant progression in phyllodes tumors by immunohistochemistry using the 10E4 monoclonal antibody. The epitope of 10E4 has been shown to consist of mixed N-sulfated and N-acetylated heparan sulfate.…”