CYP3A4 Expression in Breast Cancer and its Association with Risk Factors in Mexican Women

Background: In Mexico, breast cancer (BCa) is the leading type of cancer in women. Cytochrome P450(CYP450) is a superfamily of major oxidative enzymes that metabolize carcinogens and many antineoplasticdrugs. In addition, these enzymes have influence on tumor development and tumor response to therapy. Inthis report, we analyzed the protein expression in patients with BCa and in healthy women. Links with someclinic-pathological characteristic were also assessed. Materials and
Methods: Immunohistochemical analyseswere conducted on 48 sets of human breast tumors and normal breast tissues enrolled in Hospital Militar deEspecialidades de la Mujer y Neonatologia and Hospital Central Militar, respectively, during the time periodfrom 2010 to 2011. Informed consent was obtained from all participants. Statistical analysis was performed usingχ2 or Fisher exact tests to estimate associations and the Mann Whitney U test for comparison of group means.
Results: We found a significant CYP3A4 overexpression in BCa stroma and gland regions in comparison withhealthy tissue. A significant association between protein expression with smoking, alcoholism and hormonalcontraceptives use was also observed. Additionally, we observed estrogen receptor (ER) and progesterone receptor(PR) positive association in BCa.
Conclusions: We suggest that CYP3A4 expression promotes BCa developmentand can be used in the prediction of tumor response to different treatments. One therapeutic approach may thusbe to block CYP3A4 function.