Expression patterns of biologic markers in small breast cancers and preneoplastic breast lesions

Analysis of EGFR and HER-2 expressions in ductal carcinomas in situ in canine mammary glands

Biomolecular evidence has shown that ductal carcinoma in situ(DCIS) may develop into invasive carcinoma of the canine mammary gland, and mutations in proto-oncogenes HER2 and EGFR; two members of the family of epidermal growth factor receptors, may be involved in this process. The purpose of this study was the characterization of the immunohistochemical expression of the EGFR and HER2 proteins in the process of neoplastic transformation, supposedly present in ductal carcinomas in situin canine mammary glands. Fifteen cases of DCIS were evaluated, with a higher expression of HER2 and EGFR being observed in low-grade carcinomas when compared with high-grade neoplasms, and with a high positive statistical correlation in the latter. Results suggest that aggressive tumors tend to lose the expression of EGFR and HER2 simultaneously. The loss of the expression of these markers may be related to the process of neoplastic progression in canine mammary tumors.

Precursors and preinvasive lesions of the breast: the role of molecular prognostic markers in the diagnostic and therapeutic dilemma

Precursors and preinvasive lesions of the breast include atypical ductal hyperplasia (ADH), ductal carcinoma in situ (DCIS), and lobular neoplasia (LN). There is a significant debate regarding the classification, diagnosis, prognosis and management of these lesions. This review article describes the current theories regarding the pathogenesis and molecular evolution of these lesions. It reviews the implication of a variety of molecules in the continuum of breast lesions: estrogen receptors (ER-alpha and ER-beta), c-erb-B2 (Her2/neu), p53, Ki-67, bcl-2, E-cadherin, transforming growth factor-beta (TGF-beta), p27 (Kip1), p16 (INK4a), p21 (Waf1), vascular endothelial growth factor (VEGF). With respect to the aforementioned molecules, this article reviews their pathophysiological importance, and puts the stress on whether they confer additional risk for invasive breast cancer or not. This knowledge has the potential to be of importance in the therapeutic decisions presenting in the common clinical practice.

CD44s is useful in the differentiation of benign and malignant papillary lesions of the breast

BACKGROUND/AIMS

CD44s, the standard form of CD44, has been shown to be downregulated during malignant transformation of breast cancers. It has also been reported recently to be a useful marker in differentiating between benign and malignant papillary lesions of the breast, with high expression in the former. CD44s expression in benign and malignant papillary lesions was evaluated.

METHODS

CD44s expression was assessed by immunohistochemistry in 101 benign papillomas and 59 papillary carcinomas (seven invasive papillary carcinomas, 41 papillary ductal carcinomas in situ, and 11 ductal carcinomas involving papillomas).

RESULTS

Patients' age and tumour size were significantly different between the papilloma and papillary carcinoma groups (p < 0.0001). CD44s showed positive staining in 45 papillomas (45%) and five papillary carcinomas (8%), and the difference was significant (p < 0.0001). The myoepithelial cells, when present, were also positive for CD44s in both groups, with no observable differences. Using CD44s positive staining to differentiate between benign and malignant papillary lesions gives a sensitivity, specificity, and accuracy of 45%, 92%, and 62%, respectively.

CONCLUSIONS

CD44s may be useful as an adjunct in the evaluation of morphologically problematic cases of papillary lesion of the breast.