Human Epidermal Growth Factor Receptor-2 gene polymorphism and breast cancer risk in women from the Northeastern region of Brazil.

OBJECTIVES: In the Human Epidermal Growth Factor Receptor-2 (HER2) rs1136201 variant, the presence of the G allele may promote cellular alterations and increase breast cancer risk, in addition to enhanced cellular proliferation, tumor aggressiveness, and metastases. The aim of this study was to investigate the presence of the single-nucleotide polymorphism (SNP) variant, rs1136201, within the HER2 gene in women from the Northeastern region of Brazil and breast cancer risk. METHODS: The study included 140 women who were divided into two groups, case (breast cancer) and control (without breast cancer), with 70 women in each group. Peripheral blood of each woman was drawn for the study of genomic Deoxyribonucleic acid (DNA) extracted from leukocytes using the genotyping technique by real-time polymerase chain reaction. RESULTS: The GG genotype occurred in 1 woman in both groups (1.4%) (p=0.32), while the AG genotype occurred in 19 (27.2%) and 13 (18.6%) women in the case and control (p=1.00) groups, respectively. No statistically significant difference in GG and AG genotypes was observed between the case and control groups in premenopausal women (p=1.00). Furthermore, no significant difference in genotypes was observed between the groups, among postmenopausal women (p=0.14). CONCLUSION: In this study, the HER2 rs1136201 polymorphism did not show any statistically significant association with breast cancer, both in premenopausal and postmenopausal women. Nevertheless, further studies with a larger sample size should be performed to assess the association of HER2 polymorphism with breast cancer risk in women from the Northeastern region of Brazil.

Bcl-2 antigen expression in luminal A and triple-negative breast cancer.

Biomarkers for the prognosis of breast cancer have been routinely used in clinical practice, including the expression of hormone receptors, Ki-67 and HER-2. More recently, Bcl-2 has been recognized as an important prognostic factor in breast cancer, although controversies persist with respect to the significance of its expression. The aim of the present study was to evaluate Bcl-2 antigen expression in luminal A and triple-negative breast cancer. Sixty women with invasive ductal carcinoma were included in the study and divided into two groups: Group A (luminal A) and Group B (triple-negative), with 30 cases in each group. Immunohistochemistry was performed on tissue sections to evaluate Bcl-2 antigen expression. Fisher's exact test was used to compare the proportions of cases with cells expressing Bcl-2 between the two subtype cancer groups, with statistical significance being established at p < 0.05. The number of cases with cells expressing Bcl-2 in Groups A and B was 26 (86.7%) and 12 (40.0%), respectively (p < 0.0003). In the present study, the expression of the anti-apoptotic protein Bcl-2 was greater in luminal A breast cancer tissue samples compared to triple-negative breast cancer.

Human Epidermal Growth Factor Receptor-2 gene polymorphism and breast cancer risk in women from the Northeastern region of Brazil

OBJECTIVES: In the Human Epidermal Growth Factor Receptor-2 (HER2) rs1136201 variant, the presence of the G allele may promote cellular alterations and increase breast cancer risk, in addition to enhanced cellular proliferation, tumor aggressiveness, and metastases. The aim of this study was to investigate the presence of the single-nucleotide polymorphism (SNP) variant, rs1136201, within the HER2 gene in women from the Northeastern region of Brazil and breast cancer risk. METHODS: The study included 140 women who were divided into two groups, case (breast cancer) and control (without breast cancer), with 70 women in each group. Peripheral blood of each woman was drawn for the study of genomic Deoxyribonucleic acid (DNA) extracted from leukocytes using the genotyping technique by real-time polymerase chain reaction. RESULTS: The GG genotype occurred in 1 woman in both groups (1.4%) (p=0.32), while the AG genotype occurred in 19 (27.2%) and 13 (18.6%) women in the case and control (p=1.00) groups, respectively. No statistically significant difference in GG and AG genotypes was observed between the case and control groups in premenopausal women (p=1.00). Furthermore, no significant difference in genotypes was observed between the groups, among postmenopausal women (p=0.14). CONCLUSION: In this study, the HER2 rs1136201 polymorphism did not show any statistically significant association with breast cancer, both in premenopausal and postmenopausal women. Nevertheless, further studies with a larger sample size should be performed to assess the association of HER2 polymorphism with breast cancer risk in women from the Northeastern region of Brazil.