Expression of Nrf2 and NF-κB transcription factors in breast cancer and breast fibroadenoma: Insights for a new therapeutic approach.

Background: Cancer and fibroadenoma are the most common breast tumors in women of reproductive age. Nuclear factor erythroid 2-related factor 2 (Nrf2) and the nuclear factor kappaB (NF-κB) transcription factor play an important role in the inflammatory process and in cell proliferation. However, few studies have analyzed these markers in breast cancer and fibroadenoma in women of reproductive age. Results: Light microscopy showed a higher concentration of anti-Nrf2 and anti-NF-κB-stained nuclei in breast cancer than in fibroadenoma. The mean percentage of stained nuclei for Nrf2 was 7.12 ± 5.2 and 43.21 ± 19.83 in the control and study groups, respectively (p < 0.0001). The mean percentage of anti-NF-κB was 10.75 ± 7.09 and 56.14 ± 21.19 (mean ± standard deviation) in the control and study groups, respectively (p < 0.0001). Histological grade 3 tumors showed a significantly higher expression of Nrf2 and NF-κB than grade 1 tumors (p < 0.05). Material and methods: This study was approved by the Institutional Review Board of Federal University of Piaui and all patients assigned an inform consent term prior to the study initiation. Nrf2 and NF-κB expression was evaluated by immunohistochemistry in 66 patients, divided into two groups, control (fibroadenoma, n = 36) and study (cancer, n = 30). The data were analyzed using ANOVA test and the statistical significance was established at p < 0.05. Conclusion: Nrf2 and NF-κB expression was significantly higher in breast cancer than in fibroadenoma, in addition to having a greater association with more aggressive tumors.

CYP2D6 gene polymorphisms in Brazilian patients with breast cancer treated with adjuvant tamoxifen and its association with disease recurrence.

At present, there is controversy regarding the efficacy of tamoxifen in breast cancer patients who are carriers of cytochrome P450 2D6 (CYP2D6) gene polymorphisms, in terms of recurrence and overall survival. Thus, the aim of the present study was to investigate the association of the CYP2D6 *4, *10 and *17 gene polymorphisms with breast cancer recurrence in a Brazilian population. The cohort comprised 40 receptor-positive breast cancer patients without recurrence and 40 with distant recurrence. A 3-ml sample of peripheral blood was collected from each patient to determine the presence of the *4, *10 and *17 single nucleotide polymorphisms of the CYP2D6 gene by quantitative polymerase chain reaction analysis. There was no statistically significant difference between the two groups regarding the polymorphism frequency (P=0.246). The results revealed that intermediate metabolizers occurred in 5% of patients without recurrence and in 15% of those with distant recurrence. Poor metabolizers occurred in only 1 patient (2.5%) per group, and there was no significant difference between the groups (P=0.789). The present study concluded that the CYP2D6 gene polymorphism in women with hormone-sensitive breast cancer treated with tamoxifen was not associated with disease recurrence.

Immunohistochemical expression of E-cadherin in sclerosing adenosis, ductal carcinoma in situ and invasive ductal carcinoma of the breast.

E-cadherin (EC) is an important glycoprotein cell-adhesion molecule that appears to play a significant role in the progression of breast lesions. The objective of this study was to evaluate EC expression in sclerosing adenosis, ductal carcinoma in situ and invasive ductal carcinoma. Samples of breast lesions from 44 women were used in this study, comprising cases of sclerosing adenosis (n = 11), ductal carcinoma in situ (DCIS) (n = 10) and invasive ductal carcinoma (n = 23). Immunohistochemical evaluation of EC expression was assessed semiquantitatively and considered negative (<10% of cells with stained cytoplasmic membranes), positive+ (10-50% of cells stained) or positive++ (> 50% of cells stained). Fisher's exact test was used to compare the distribution of staining intensity in the lesions (P< 0.05). There was a progressive loss of EC expression from benign to malignant lesions. This difference was statistically significant when sclerosing adenosis was compared with DCIS (P < 0.0002), when sclerosing adenosis was compared with invasive ductal carcinoma (P < 0.008) and when DCIS was compared with invasive ductal carcinoma (P < 0.007). The present findings point to a significant association between reduced EC expression and the progression and aggressivity of breast lesions. Diagn. Cytopathol. 2010. (c) 2009 Wiley-Liss, Inc.