BMC Cancer Research article BioMed Central Open Access Examination of polymorphic glutathione S-transferase (GST) genes, tobacco smoking and prostate cancer risk among Men of African Descent: A case-control study Nicole A Lavender1,2, Marnita L Benford1,2, Tiva T VanCleave1,2, Guy N Brock2,3,4,5, Rick A Kittles6, Jason H Moore7, David W Hein1,2,4,5 and La Creis R Kidd*1,2,8 Address: 1Department of Pharmacology & Toxicology, University of Louisville (UofL), School of Medicine, 500 South Preston Street, Room 1319 Research Tower, UofL Health Science Center, Louisville, KY 40202, USA, 2James Graham Brown Cancer Center, Cancer Prevention & Control Program, UofL, 529 South Jackson Street, Louisville, KY 40202, USA, 3Department of Bioinformatics & Biostatistics, UofL School of Public Health and Information Sciences, 485 East Gray Street, Louisville, KY 40202, USA, 4Center for Genetics and Molecular Medicine, UofL School of Medicine, Delia B. Baxter Biomedical Research Building, Suite 221, Louisville, Kentucky 40202, USA, 5Center for Environmental Genomics and Integrative Biology, UofL, Delia B. Baxter Biomedical Research Building, Suite 221, Louisville, Kentucky 40202, USA, 6Department of Medicine, University of Chicago, 5841 S. Maryland Ave, MC Chicago, Illinois 606037, USA, 7Dartmouth -Hitchcock Medical Center, Dartmouth Medical School, 706 Rubin Building, HB 7937 One, Medical Center Drive, Dartmouth-Hitchcock Medical Center Lebanon, NH 03756, USA and 8Department of Epidemiology and Public Health, UofL School of Public Health and Information Sciences, 485 East Gray Street, Louisville, KY 40202, USA Email: Nicole A Lavender - nalave01@louisville.edu; Marnita L Benford - mlbenf01@louisville.edu; Tiva T VanCleave - tmtemp01@louisville.edu; Guy N Brock - guy.brock@louisville.edu; Rick A Kittles - rkittles@medicine.bsd.uchicago.edu; Jason H Moore - jason.h.moore@dartmouth.edu; David W Hein - dwhein01@gwise.louisville.edu; La Creis R Kidd* - lrkidd01@gwise.louisville.edu * Corresponding author Published: 16 November 2009 BMC Cancer 2009, 9:397 doi:10.1186/1471-2407-9-397 This article is available from: http://www.biomedcentral.com/1471-2407/9/397 Received: 13 July 2009 Accepted: 16 November 2009 © 2009 Lavender et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Abstract Background: Polymorphisms in glutathione S-transferase (GST) genes may influence response to oxidative stress and modify prostate cancer (PCA) susceptibility. These enzymes generally detoxify endogenous and exogenous agents, but also participate in the activation and inactivation of oxidative metabolites that may contribute to PCA development. Genetic variations within selected GST genes may influence PCA risk following exposure to carcinogen compounds found in cigarette smoke and decreased the ability to detoxify them. Thus, we evaluated the effects of polymorphic GSTs (M1, T1, and P1) alone and combined with cigarette smoking on PCA susceptibility. Methods: In order to evaluate the effects of GST polymorphisms in relation to PCA risk, we used TaqMan allelic discrimination assays along with a multi-faceted statistical strategy involving conventional and advanced statistical methodologies (e.g., Multifactor Dimensionality Reduction and Interaction Graphs). Genetic profiles collected from 873 men of African-descent (208 cases and 665 controls) were utilized to systematically evaluate the single and joint modifying effects of GSTM1 and GSTT1 gene deletions, GSTP1 105 Val and cigarette smoking on PCA risk. Results: We observed a moderately significant association between risk among men possessing at least one variant GSTP1 105 Val allele (OR = 1.56; 95%CI = 0.95-2.58; p = 0.049), which was confirmed by MDR permutation testing (p = 0.001). We did not observe any significant single gene effects among GSTM1 (OR = 1.08; 95%CI = 0.65-1.82; p = 0.718) and GSTT1 (OR = 1.15; 95%CI = Page 1 of 10 (page number not for citation purposes)