A case-control study of the HER2 Ile655Val polymorphism and risk of breast cancer in Taiwan.

OBJECTIVES: To investigate the HER2 Ile655Val polymorphism in relation to risk of breast cancer in a case-control study in Taiwan. DESIGN AND METHODS: The HER2 polymorphism at codon 655 was analyzed in 424 patients with breast cancer and 318 controls by using the polymerase chain reaction methodology, followed by the restriction fragment-length polymorphism (PCR-RFLP) analysis. RESULTS: There was a 1.48-fold (95% CI=1.00-2.24) increase in the risk of patients with breast cancer who are Val carrier (Ile/Val and Val/Val genotypes). Furthermore, for the early onset (less than 45 years old) breast cancers with Val carrier, there was a 2.24-fold (95% CI=1.17-4.34) increase in the risk of breast cancer. CONCLUSIONS: Our results indicate that the Val carrier was associated with increased risks in patients with breast cancer in Taiwan. The association was more apparent in patients who were younger than or equal to 45 years of age.

Expression of epidermal growth factor receptor in human middle ear cholesteatoma.

Middle ear cholesteatoma is destructive to auditory ossicles and temporal bone, and treatment usually includes surgical removal of all epithelial content in the tympanomastoid cavity. Epidermal growth factor receptor (EGFR) is a 170 kd to 180 kd transmembrane glycoprotein and its distribution density is related to the ability of the keratinocytes to differentiate and their state of differentiation. We used the avidin-biotin complex technique and EGFR monoclonal antibody to evaluate the expression of EGFR in 29 cases of cholesteatoma and 34 samples of normal postauricular skin. Of patients with cholesteatoma, 79% (23 cases) had EGFR-positive cells in the basal layer, 66% (19 cases) in the parabasal layer, and 62% (18 cases) in the upper layer of the epithelial tissue. Among patients with normal postauricular skin, 85% (29 cases) had EGFR-positive cells in the basal layer, 79% (27 cases) in the parabasal layer, and 79% (27 cases) in the upper layer of the epithelial tissue. No statistical difference in EGFR expression between each layer of cholesteatoma and postauricular skin was noted. However, there was an intensity gradient of positive EGFR immunoreactivity from the basal to the higher layers in cholesteatoma. Our results showed that the distribution of EGFR in middle ear cholesteatoma is not deranged, but is similar to that in normal skin tissue.

Epidermal growth factor expression in middle ear cholesteatoma.

Middle ear cholesteatoma is destructive to auditory ossicles and temporal bone, and treatment usually requires surgical removal of all epithelial content. Epidermal growth factor (EGF) can stimulate the growth and differentiation of a variety of mammalian cells, including epithelial cells. Our study used the avidin-biotin complex technique to evaluate the expression of EGF in 40 cases of middle ear cholesteatoma (active cholesteatoma, 31 cases; inactive cholesteatoma, 9 cases) and 34 normal postauricular skin samples. In middle ear cholesteatoma, EGF was expressed in squamous epithelium in 21 cases (53%), fibroblasts in two cases (5%), and cholesteatoma endothelium in two cases (5%). In normal postauricular skin, EGF was expressed in squamous epithelium in 14 samples (41%), fibroblasts in one sample (3%), and endothelium in none. No statistical difference in EGF expression was found between cholesteatoma and normal postauricular skin samples. These results show that the distribution of EGF in middle ear cholesteatoma is not deranged and that the progression of cholesteatoma might be induced by the release of factors from the cholesteatoma matrix via autocrine stimulation, or by inflammatory cells of the subepithelial tissue through paracrine stimulation, or in both of these ways.