title: Role of hormonal and environmental factors on early incidence of breast cancer in Iran.
abstract: Although the probability of having breast cancer increases with the age in general, this malignancy affects Iranian women at least one decade younger than their counterparts in other countries. However the underlying risk factors for the discrepancy have not been identified. The aryl hydrocarbon receptor (AhR) mediates the effects of many environmental endocrine disruptors and contributes to the loss of normal ovarian function in polluted environments. This study was aimed to compare the interactions between AhR and other fundamental genes (p53, K-Ras, ER, PgR) in a clinical setting. To conduct the immunohistochemical studies using appropriate monoclonal antibodies, 25 premenopausal invasive ductal carcinoma, 29 postmenopausal invasive ductal carcinoma and 30 breast fibroadenoma were selected retrospectively from 2004 to 2007 in the pathology department of Imam Khomeini hospital complex of Tehran University of Medical Sciences . Higher levels of AhR in epithelial cells of premenopausal patients and breast fibroadenoma emphasized the susceptibility of these cells to environmental-induced tumors. AhR overexpression contributed to ER-/PgR-immunophenotype in young/premenopausal patients but the same pattern was not observed in benign and postmenopausal malignant tumors. It seems that early incidence of breast cancer in Iran is the result of interactions between hormonal and environmental factors.
authors.affiliation: Department of Toxicology & Pharmacology, Pharmaceutical Sciences Branch, Islamic Azad University(IAUPS), Tehran, Iran. arbabi.s@iaups.ac.ir
authors.forename: Sepideh Arbabi
authors.initials: SA
authors.lastname: Bidgoli
authors.forename: Raziyeh
authors.initials: R
authors.lastname: Ahmadi
authors.forename: Mansour Djamali
authors.initials: MD
authors.lastname: Zavarhei
mesh_terms: D000293:Adolescent; D000328:Adult; D001943:Breast Neoplasms / Q000453:epidemiology* / Q000209:etiology / Q000378:metabolism; D004781:Environmental Exposure / Q000706:statistics & numerical data; D004784:Environmental Monitoring; D062665:Epidemiological Monitoring; D005260:Female; D018226:Fibroadenoma / Q000453:epidemiology / Q000209:etiology / Q000378:metabolism; D006801:Humans; D015994:Incidence; D007492:Iran / Q000453:epidemiology; D008875:Middle Aged; D015689:Oncogene Protein p21(ras) / Q000378:metabolism; D018336:Receptors, Aryl Hydrocarbon / Q000378:metabolism*; D011960:Receptors, Estrogen / Q000378:metabolism*; D011980:Receptors, Progesterone / Q000378:metabolism*; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism; D055815:Young Adult
chemical_list: D018336:Receptors, Aryl Hydrocarbon; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; D016159:Tumor Suppressor Protein p53; D015689:Oncogene Protein p21(ras)