Asian Pacifc Journal of Cancer Prevention, Vol 15, 2014 6121 DOI:http://dx.doi.org/10.7314/APJCP.2014.15.15.6121 Roles of AhR and EDCs in PSA Levels in Prostate Cancer Cases Asian Pac J Cancer Prev, 15 (15), 6121-6125 Introduction Prostate Cancer (PCa) is one of the most prevalent malignancies worldwide with a 16% lifetime risk. It is also considered as the second leading cause of cancer death in men in many parts of the world (Obort et al., 2013). While the recent incidence rates are markedly higher than rates observed three decades ago and some lifestyle and occupational factors could be considered as strong predictors of the occurrence of prostate cancer (Subahir, 2009), the most recent statistics show that prostate cancer incidence rates have now been stabilized which is thought to refect changes in utilization of prostate-specifc antigen (PSA) testing as a potential biomarker of early detection of PCa (Wright and long, 2007), Utility of Digital Rectal Examination, Serum Prostate Specific Antigen, and Transrectal Ultrasound (Kash, 2014). Although the only widely accepted screening tool for PCa are prostate-specifc antigen (PSA) and digital rectal examination, PSA is considered to be prostate specifc, but not PCa specifc, and hence lacks the sensitivity to 1 Department of Toxicology and Pharmacology, Pharmaceutical Sciences Branch (IAUPS) , Islamic Azad University, 2 Department of Pathology, Faculty of Medicine, Tehran University of Medical Sciences (TUMS),Tehran, Iran *For correspondence: sepideharbabi@ yahoo.com Abstract Background: Prostate-specifc antigen (PSA) is a potential biomarker for early detection of prostate cancer (PCa) but its level is known to be affected by many background factors and roles of ubiquitous toxicants have not been determined. Endocrine disrupting chemicals (EDCs) are ubiquitous reproductive toxicants used in consumer products, which promote tumor formation in some reproductive model systems by binding to AhR, but human data on its expression in prostate cancer as well as its association with PSA levels are not clear. This study aimed to evaluate the expression levels of AhR and its association with serological levels of PSA and to detect possible effects of background factors and EDC exposure history on PSA levels in PCa cases. Materials and Methods: A cross-sectional study was conducted on the tissue levels of AhR and serum levels of PSA in 53 PCa cases from 2008-2011 and associations between each and background and lifestyle related factors were determined. Results: Although the AhR was overexpressed in PCa and correlated with the age of patients, it did not correlate with PSA levels.Of nutritional factors, increased intake of polysaturated fats and fsh in the routine regimen of PCa cases increased the PSA levels signifcantly. Conclusions: AhR overexpression in PCa pontws to roles of EDCs in PCa but without any direct association with PSA levels. However, PSA levels are affected by exposure to possible toxicants in foods whichneed to be assessed as possible risk factors of PCa in future studies. Keywords: Prostate cancer - PCa - PSA - endocrine disrupting chemicals - EDCs - AhR - environmental factors RESEARCH ARTICLE Prostate-Specifc Antigen Levels in Relation to Background Factors: Are there Links to Endocrine Disrupting Chemicals and AhR Expression? Sepideh Arbabi Bidgoli 1 *, Nasim Jabari 1 , Mansour Djamali Zavarhei 2 detect a large number of tumors, especially during the early stages (Jason and Crawford, 2011). Moreover the PSA level is known to be affected by many factors, such as therapeutic regimens, previous infammation (benign prostate hyperplasia and prostatitis),nutritional and occupational factors and urologic manipulation; hence, the controversy regarding the role of environmental factors on the incidence of PCa, (Segev and Nativ, 2006; van Weerden and Schroder, 2008; Kaba, 2014) as well as the possible role of environmental factors on PSA levels (Prins, 2008) and background factors (Ozbek, 2014) has been remained inconclusive. Epidemiological evidence suggests that environmental factors, such as diet (Ho et al., 2011), occupation (Koifman et al., 2002; Karimi et al., 2012), metrological parameters (St-Hilaire et al., 2010) and other lifestyle factors may play signifcant roles on the development and progression of PCa. Out of these wide range of factors a great deal of interest is being directed towards the supposition that excessive exposure to endocrine disruptors or modulators and elevated polycyclic aromatic hydrocarbon-DNA