The association of cyclin D1 G870A and E-cadherin C-160A polymorphisms with the risk of colorectal cancer in a case control study and meta-analysis Xiang-Lin Tan 1,2 * , Alexandra Nieters 1 , Silke Kropp 1 , Michael Hoffmeister 3 , Hermann Brenner 3 and Jenny Chang-Claude 1 1 Division of Cancer Epidemiology, German Cancer Research Center, Heidelberg, Germany 2 Laboratory of Human Toxicology and Molecular Epidemiology, Wadsworth Center, New York State Department of Health, Albany, NY 3 Division of Clinical Epidemiology and Aging Research, German Cancer Research Center, Heidelberg, Germany Cyclin D1 (CCND1) and E-cadherin (CDH1) have been shown to be important genes of the b-catenin/LEF pathway that is involved in colorectal carcinogenesis. However, epidemiological studies on relationship between genetic variants of these two genes and color- ectal cancer (CRC) have shown inconsistent results. In a popula- tion-based case-control study (498 cases and 600 controls), we assessed the association of CCND1 G870A and CDH1 C-160A polymorphisms with CRC risk. Multivariable logistic regression analysis was used to estimate the association between genotypes, environmental exposures and CRC risk, adjusting for potential confounders. Compared to common homozygotes, the OR for het- erozygous and homozygote variant genotype was 1.08 (95% CI, 0.80–1.46) in CCND1 and 0.97 (95% CI, 0.75–1.25) in CDH1. Nei- ther tumor stage nor location showed an association with genetic susceptibility. However, a significant interaction between hormone replacement therapy (HRT) and CCND1 genotypes in CRC risk was found among postmenopausal women (p interaction 5 0.02). The risk reduction associated with HRT was substantial (OR, 0.09; 95% CI, 0.02–0.35) in women who were GG homozygous. A meta- analyses including 11 published studies on CCND1 G870A in addi- tion to our study showed a slightly increased risk of CRC for carriers of the A allele (OR, 1.19; 95% CI, 1.06–1.34); however, there was some indication of publication bias. We conclude that the CCND1 G870A and CDH1 C-160A polymorphisms are not associated with the risk of CRC in the German population. How- ever, the CCND1 G870A polymorphism may modify the protective effect of postmenopausal hormone use on the development of CRC. ' 2008 Wiley-Liss, Inc. Key words: colorectal cancer; cyclin D1; E-cadherin; genetic polymorphism Aberrant activation of Wnt/b-catenin signalling, due to muta- tions in component enzyme of the pathway, is thought to be an ini- tiating event in colorectal carcinogenesis. 1 b-Catenin associates with TCF/LEF (T cell factor/lymphocyte enhancer factor) tran- scription factors to activate target genes that enhance proliferation and cell survival, and thus impact on the development of colorec- tal cancer (CRC). 2 Therefore, polymorphisms of the genes involved in Wnt/b-catenin signalling pathway are likely to play a role in determining the individual susceptibility to CRC. Cyclin D1 (CCND1) is a key cell cycle regulator from G1 to S phase. The CCND1 gene is a direct target for transactivation by the the b-catenin /LEF-1 pathway through a LEF-1 binding site in the CCND1 promoter. 3 A common G870A polymorphism in exon 4 of the CCND1 gene is known to modulate the frequency of alter- nate splicing and probably reduce transcript levels. 4 A number of studies have linked the CCND1 870A allele to increased cancer risk, but the evidence is not entirely consistent, and some con- troversy exists regarding the effects on CRC development (Table I). 5–15 E-cadherin (CDH1) is a well-characterized cell–cell adhesion molecule leading to increased cell mobility and possibly increased activity of b-catenin/TCF transcription factor complex. 17 CDH1 C-160A promoter polymorphism was shown to markedly affect CDH1 transcription, thus suppressing CDH1 expression. 18 Several studies have examined the relationship between the CDH1 C- 160A polymorphism and cancers of the stomach, 19–21 breast, 22 colon, 13,16 bladder 23–25 and prostate 26–31 with controversial results. Few studies have assessed potential interactions between dietary and other environmental risk factors and these two poly- morphisms, but it has been recently reported that CCND1 G870A genotype may enhance the protective effect of postmenopausal hormone use on the development of colorectal neoplasia. 7 To further investigate the role of the b-catenin/LEF pathway in CRC, we studied the effects of CCND1 G870A and CDH1 C- 160A polymorphisms on the risk of CRC in a German population- based case-control study. At the same time, a meta-analysis was done to systematically follow-up the prior reports. Material and methods Study subjects and data collection As previously reported, 32,33 patients who were diagnosed for the first time with invasive CRC (ICD 10 pos. C18–C20) between January 2003 and June 2004 were recruited from 22 hospitals in the Rhine-Neckar-region in the South-West of Germany. Controls were randomly selected from population registers and frequency- matched with cases by sex, residence and 5-year age groups. Con- trol individuals with a history of CRC were excluded. Cases as well as controls were eligible if they were aged 30 or older, spoke German and were physically and mentally able to participate in a personal interview of about 1 hr. The study was approved by the ethics committees of the University of Heidelberg and of the state medical associations of Baden-W€ urttemberg and Rhineland-Palat- inate. All study participants provided written informed consent. Data were collected in person by trained interviewers at the hos- pital or at the participant’s home. The questionnaire collected in- formation on demographic and lifestyle factors, a detailed medical and family history, as well as on known and suspected risk factors for CRC. For patients, we additionally requested histology reports and discharge letters. Information on prior endoscopies of the large intestine was validated by patient medical record from the physicians who carried out the examination; and the information for self-reported start, end, total duration and reason of hormone replacement therapy (HRT) use was available from the interview. Details of menstruation history and removal of the uterus and ova- ries were assessed. Menopausal status at index date was defined by reported history of the women. Postmenopausal women were those whose menstrual periods had stopped naturally or after bilat- eral oophorectomy, radiation therapy or chemotherapy, and all women older than age 55. However, menopausal state can be masked if hysterectomy was the reason for the cessation of the Grant sponsor: Deutsche Forschungsgemeinschaft (German Research Foundation; Grant numbers: BR 1704/6-1, BR 1704/6-3, CH 117/1-1. *Correspondence to: Laboratory of Human Toxicology and Molecular Epidemiology, Wadsworth Center, New York State Department of Health, E632, Empire State Plaza, Albany, NY, USA. Fax: 518-473-2895. E-mail: txlintf@hotmail.com Received 24 July 2007; Accepted after revision 14 November 2007 DOI 10.1002/ijc.23363 Published online 14 January 2008 in Wiley InterScience (www.interscience. wiley.com). Abbreviations: BMI, body mass index; CCND1, cyclin D1; CDH1, E- cadherin; CI, confidence interval; CRC, colorectal cancer; HRT, hormone replacement therapy; TCF, T cell factor; LEF, lymphocyte enhance prolif- eration; IGF, insulin-like growth factor; OR, odds ratio. Int. J. Cancer: 122, 2573–2580 (2008) ' 2008 Wiley-Liss, Inc. Publication of the International Union Against Cancer