A case-control study of Parkinson's disease and tobacco use: gene-tobacco interactions.

A case-control study of genetic, environmental, and occupational risk factors for Parkinson's disease (PD) was carried out in five European countries (Italy, Malta, Romania, Scotland, and Sweden) to explore the possible contribution of interactions among host and environmental factors in sporadic PD. Whereas smoking habits confirmed its negative association with PD, a possible modulatory role of genetic polymorphisms was investigated to obtain further mechanistic insights. We recruited 767 cases of PD and 1989 age-matched and gender-matched controls. Participants completed an interviewer-administered questionnaire including the history of smoking habits. The polymorphisms of genes involved either in metabolism of compounds contained in tobacco smoke (CYP2D6, CYP1B1, GSTM1, GSTT1, GSTM3, GSTP1, NQO1, SOD2, EPHX and NAT2) or in dopaminergic neurotransmission (MAOA, MAOB, DAT1 and DRD2) were characterized by PCR based methods on genomic DNA. We found evidence of statistically significant gene-tobacco interaction for GSTM1, NAT2, and GSTP1, the negative association between tobacco smoking and PD being significantly enhanced in subjects expressing GSTM1-1 activity, in NAT2 fast acetylators, and in those with the GSTP1*B*C haplotype. Owing to the retrospective design of the study, these results require confirmation.

Oral contraceptive use and BRCA penetrance: a case-only study.

BACKGROUND: Women with deleterious mutations in BRCA genes are at increased risk of breast cancer. However, the penetrance of the genetic trait may be regulated through environmental factors. This multinational case-only study tested the interaction between oral contraceptive use and genetic susceptibility in the occurrence of breast cancer. METHODS: We recruited 3,123 patients diagnosed with breast cancer before the age of 45 years. Participants were classified according to their probability of carrying a BRCA mutation on the basis of their family history of breast and ovarian cancer. According to a case-only approach, the frequency of relevant exposures among breast cancer cases with high probability of BRCA mutation ("genetic cases") was compared with the frequency of the same exposures among breast cancer cases with a low probability of BRCA mutation ("sporadic cases"). The interaction odds ratios (OR) and 95% confidence intervals (CI) for oral contraceptive use were estimated by unconditional logistic regression, after controlling for potentially confounding variables. RESULTS: The analysis was carried out comparing 382 "genetic" and 1,333 "sporadic" cases. We found a borderline significant interaction between genetic breast cancer and oral contraceptive use for ever users compared with never users (OR, 1.3; 95% CI, 1.0-1.7). The greatest interaction OR was found for women who started using pill at 18 to 20 years (OR, 1.6; 95% CI, 1.1-2.3). CONCLUSION: These results suggest that BRCA mutation carriers, as well as women with a significant family history of breast and ovarian cancer are more vulnerable to exogenous hormones in oral contraceptives.

Facial features in children with idiopathic congenital talipes equinovarus.

We assessed whether there is a recognisable pattern of facial morphology in photographs of a series of 62 children with idiopathic congenital talipes equinovarus (CTEV). Photographs were scored for a number of facial characteristics by a research team comprising orthopaedic surgeons and clinical geneticists, to identify a subgroup of children with idiopathic CTEV, who shared characteristic facial features. Seven children were identified as having a "CTEV face". There was good correlation between the "CTEV face" and the individual facial features. Repeatability of the assessment was good, and there was good correlation between the geneticists and the orthopaedic surgeons, suggesting that no special training in dysmorphology is required to identify the "CT EV face". There is a subgroup of children with idiopathic CTEV who can be reliably identified by their facial characteristics. The significance of this finding is unclear but it may be of use in clinical genetic studies, and studies of the aetiology of CTEV.

Probability estimation models for prediction of BRCA1 and BRCA2 mutation carriers: COS compares favourably with other models.

BACKGROUND: Accurate risk assessment is essential to genetic counselling for a family history of cancer. Several empiric and computer-based risk assessment models have been developed to estimate a counselee's probability of being a carrier of mutation in BRCA1 and/or 2 genes, and to predict the risk of developing breast cancer. The COS model was developed from the better-known BRCAPro model to estimate risk of carriage of BRCA1 or 2 mutation. The COS model remains to be validated in a population discrete from that used for its development. METHODS: Four probability estimation models including COS, Manchester scoring system (MSS), BOADICEA and Tyrer-Cuzick (T-C) were applied to 275 Scottish families tested for BRCA1/2 mutations ascertained through regional genetics centres to ascertain models' sensitivity, specificity and accuracy. A subset of 130 families from Grampian (North and Northeast Scotland) was used to assess the models' ability to estimate the prevalence of BRCA1/2 mutation carriers. Sensitivity, specificity and ROC plots were used to ascertain models' individual performance, in terms of number of cancer cases, type of cancer and age of diagnosis of breast cancer. RESULTS: The COS and MSS models demonstrated the greatest sensitivities and area under ROC curves for the majority of family structures. They also showed the highest sensitivities (91-92%) and AUCs (76-78%) for the entire dataset overall. However, BOADICEA and T-C had the highest specificities for the majority of the family structures. BOADICEA and T-C generated the best estimates for the prevalence of mutations in the population; BOADICEA was more accurate for BRCA1 and T-C for BRCA2. CONCLUSION: The COS and MSS models are the most effective models for use in clinical practice to select families for mutation analysis, but BOADICEA and T-C are more accurate for estimating mutation prevalence within a population.

Polymorphisms in the methylenetetrahydrofolate reductase (MTHFR) gene, intakes of folate and related B vitamins and colorectal cancer: a case-control study in a population with relatively low folate intake.

Folate is key in one-carbon metabolism, disruption of which can interfere with DNA synthesis, repair, and methylation. Efficient one-carbon metabolism requires other B vitamins and the optimal activity of enzymes including 5,10-methylenetetrahydrofolate reductase (MTHFR). We report a population-based case-control study of folate intake, related dietary factors and MTHFR polymorphisms (C677T, A1298C) and colorectal cancer in a population with relatively high colorectal cancer incidence and relatively low folate intake. A total of 264 cases with histologically confirmed incident colorectal cancer and 408 controls participated. There was no clear trend in risk with reported intakes of total, or dietary, folate, riboflavin, vitamin B12 or vitamin B6, nor were there interactions between folate intake and the other B vitamins or alcohol. For C677T, risk decreased with increasing variant alleles (multivariate OR for CT v. CC = 0.77 (95 % CI 0.52, 1.16); OR for TT v. CC = 0.62 (95 % CI 0.31, 1.24)), which, although not statistically significant, was consistent with previous studies. For A1298C, compared with AA subjects, CC subjects had modest, non-significant, reduced risk (multivariate OR = 0.81 (95 % CI 0.45, 1.49)). There were significant interactions between total folate and C677T (P = 0.029) and A1298C (P = 0.025), and total vitamin B6 and both polymorphisms (C677T, P = 0.016; A1298C, P = 0.033), although the patterns observed differed from previous studies. Seen against the setting of low folate intake, the results suggest that the role of folate metabolism in colorectal cancer aetiology may be more complex than previously thought. Investigation of particular folate vitamers (for example, tetrahydrofolate, 5,10-methylenetetrahydrofolate) may help clarify carcinogenesis pathways.

Human fetal testis Leydig cell disruption by exposure to the pesticide dieldrin at low concentrations.

BACKGROUND: Declining human reproductive health over the last 60 years has been proposed to be due to effects of environmental chemicals, especially endocrine disrupting compounds, on fetal development. We investigated whether a model pesticide, dieldrin, at concentrations within both maternal circulation and environmental ranges (1 pmol/l = 0.0004 p.p.b. = 380.9 pg/l), could disrupt the human fetal testis. METHODS: Human fetal testes were collected during the second trimester, a critical period of male sexual differentiation (development and masculinization). Testis explants were cultured for 24 h in the presence and absence of LH (10-1000 IU LH/l) and dieldrin (1 pmol and 1 nmol/l). Endocrine, immunohistological and proteome characteristics of the tissues were investigated. RESULTS: Exposure to dieldrin reduced LH-induced testosterone secretion (P < 0.05) and tissue protein concentrations of LH receptor and steroid acute regulatory protein (P < 0.05). Dieldrin altered proteins associated with cancer, apoptosis, transcription and development. Wnt-2b was reduced 3-fold and immunolocalized to Leydig and Sertoli cells. Dieldrin also reversed some LH-induced changes in protein expression, supporting the conclusion that Leydig cell function is at risk from environmental chemicals. CONCLUSIONS: Our findings indicate that exposure to very low, biologically relevant, concentrations of environmental chemicals could affect the fetal human Leydig cell, reducing testosterone secretion and potentially leading to subtle dysregulation of reproductive development and adult fecundity.

Risk estimation for familial breast cancer: improving the system of counselling.

Women with a family history of breast cancer dominate referrals for cancer genetic risk counselling across Europe. Given limited health care resources, managing this demand, while achieving good value for money for health services, is a major challenge. The paper reports the benefits and associated costs of moving from a traditional system of deriving family history of cancer during the patient's initial clinic attendance, to a protocol-driven system with pre-counselling assessment of family history. The evaluation was based on retrospective clinical data and a clinical audit. Changes in risk between referral and final risk assessment were ascertained and the cost difference between the two systems estimated. The study results showed that 14% of women assessed as 'low' genetic risk at referral were reassessed as 'moderate' or 'high' genetic risk for breast cancer following verification of family history. Sixteen per cent of those assessed as 'moderate' or 'high' genetic risk at referral were reassessed as 'low' genetic risk for breast cancer. Compared to the traditional system, the new protocol-driven system of risk assessment was more consistent, which reduced the number of return appointments and created time for clinicians to spend with other patients. The estimated cost of family history verification and genetic clinic appointment was calculated as 91.68 pounds (132.53 euro) per family history, compared to 104.00 pounds (150.34 euro) for the traditional system, representing a slight reduction in health service costs. Finally, the protocol-driven system can be used as part of ongoing audit for planning future genetics services in Scotland.

Information recovery in cancer families: value for risk estimations.

BACKGROUND: Drawing an informative pedigree is fundamental in genetic counselling. It is very common for some parts of pedigrees to remain ambiguous because of the proband's inability to recall the past history of her/his family. Current age, date of birth, date of death and age of diagnosis are the commonest missing information in pedigrees. METHODS: The Scottish Social Statistics website, National Statistics website and English language literature were used to model extrapolations. About 172 Grampian families and three high-risk Grampian families with complete information were chosen to evaluate the influence of extrapolations on models' performance. Differences between original data and extrapolated data were assessed by independent samples t-test. RESULTS: Changes made by extrapolations in age- and cancer-related information were not statistically significant (P > 0.05) in comparison with original data, except for average age of diagnosis of breast cancer (P = 0.03). The differences made by extrapolations in estimated probabilities generated by probability assessment models were small and ignorable except that for Tyrer-Cuzick model for Grampian family 3. CONCLUSION: Extrapolations based on National Health Statistics can scientifically cover missing information in a defined population with minimum effect on performance of probability assessment models.

Colorectal cancer and genetic polymorphisms of CYP1A1, GSTM1 and GSTT1: a case-control study in the Grampian region of Scotland.

Cytochrome P-450 CYP1A1 is involved in the metabolism of polycyclic aromatic hydrocarbons (PAHs) that are derived from meat intake and tobacco smoking. Expression of the CYP1A1 gene is induced by compounds present in cruciferous vegetables. The glutathione S-transferases play a central role in the detoxification of carcinogens, including PAHs. We investigated the association between colorectal cancer and three variants (CYP1A1*2A, CYP1A1*2C, CYP1A1*4) of the CYP1A1 gene, and homozygosity for the null deletion of the GSTM1 and GSTT1 genes, and the joint effects of these genotypes and smoking, meat intake and intake of green leafy vegetables in a population-based study of 264 cases and 408 controls in Northeast Scotland. There was an inverse association with the CYP1A1*4 (m4) variant (OR 0.3, 95% CI 0.13-0.70). The OR for the CYP1A1*2C (m2) variant was 1.3 (95% CI 0.59-2.91), which is similar to a combined estimate for previous studies (OR 1.2, 95% CI 0.95-1.41). We observed no association with the CYP1A1*2A (m1) variant, or the GSTM1 and GSTT1 polymorphisms. Significant interactions between all 3 CYP1A1 variants and meat intake, and between the m1 and m2 variants and intake of green leafy vegetables, were observed. There was no evidence of interaction between CYP1A1 and smoking, and no evidence of interaction between the GSTM1 or GSTT1 polymorphisms and smoking, meat intake, green leafy vegetable intake, CYP1A1 variants or each other.

Cluster randomized trial of a multifaceted primary care decision-support intervention for inherited breast cancer risk.

BACKGROUND: GPs are increasingly expected to meet the needs of patients concerned about their risk of inherited breast cancer, but may lack skills or confidence to use complex management guidelines. We developed an evidence-based, multifaceted intervention intended to promote confidence and skills in this area. OBJECTIVE: To evaluate the effectiveness of the intervention in improving GP confidence in managing patients concerned about genetic risk of breast cancer. DESIGN: Cluster randomized controlled trial. SETTING: General practices in the Grampian region of Scotland. SUBJECTS: GPs and the patients they referred for genetic counselling for risk of breast cancer. MAIN OUTCOME MEASURES: GPs' self-reported confidence in four activities related to genetics; rates of referral of patients at elevated genetic risk; and referred patients' understanding of cancer risk factors. RESULTS: No statistically significant differences were observed between intervention and control arms in the primary or secondary outcomes. A possible effect of the intervention on the proportion of referred patients who were at elevated risk could not be discounted. Only a small proportion of intervention GPs attended the educational session, were aware or the software, or made use of it in practice. CONCLUSIONS: No convincing evidence of the effectiveness of the intervention was found, probably reflecting barriers to its use in routine practice.

Prediction of BRCA1 status in patients with breast cancer using estrogen receptor and basal phenotype.

PURPOSE: To investigate the proportion of breast cancers arising in patients with germ line BRCA1 and BRCA2 mutations expressing basal markers and developing predictive tests for identification of high-risk patients. EXPERIMENTAL DESIGN: Histopathologic material from 182 tumors in BRCA1 mutation carriers, 63 BRCA2 carriers, and 109 controls, collected as part of the international Breast Cancer Linkage Consortium were immunohistochemically stained for CK14, CK5/6, CK17, epidermal growth factor receptor (EGFR), and osteonectin. RESULTS: All five basal markers were commoner in BRCA1 tumors than in control tumors (CK14: 61% versus 12%; CK5/6: 58% versus 7%; CK17: 53% versus 10%; osteonectin: 43% versus 19%; EGFR: 67% versus 21%; P < 0.0001 in each case). In a multivariate analysis, CK14, CK5/6, and estrogen receptor (ER) remained significant predictors of BRCA1 carrier status. In contrast, the frequency of basal markers in BRCA2 tumors did not differ significant from controls. CONCLUSION: The use of cytokeratin staining in combination with ER and morphology provides a more accurate predictor of BRCA1 mutation status than previously available, that may be useful in selecting patients for BRCA1 mutation testing. The high percentage of BRCA1 cases positive for EGFR suggests that specific anti-tyrosine kinase therapy may be of potential benefit in these patients.

Genomic changes identified by comparative genomic hybridisation in docetaxel-resistant breast cancer cell lines.

Docetaxel is one of the most effective chemotherapeutic agents in the treatment of breast cancer. Breast cancers can have an inherent or acquired resistance to docetaxel but the causes of this resistance remain unclear. In this study high-level, docetaxel-resistant human breast cancer cell lines (MCF-7 and MDA-MB-231) were created, and comparative genomic hybridisation was used to identify genomic regions associated with resistance to docetaxel. MCF-7 resistant cells showed an amplification of chromosomes 7q21.11-q22.1, 17q23-q24.3, 18, and deletion of chromosomes 6p, 10q11.2-qter and 12p. MDA-MB-231 resistant cells showed a gain of chromosomes 5p, 7q11.1-q35, 9, and loss of chromosomes 4, 8q24.1-qter, 10, 11q23.1-qter, 12q15-q24.31, 14q and 18. Whole chromosome paints confirmed these findings. Amplification of 7q21 and loss of 10q may represent a common mechanism of acquired docetaxel resistance in breast cancer cells. This study is the first description of a genomic approach specifically to identify genomic regions involved in resistance to docetaxel.

Assessing patients' participation and quality of decision-making: insights from a study of routine practice in diverse settings.

In the context of a qualitative study exploring patients' participation in decision-making, we investigated how people interpret and respond to structured questions about decision-making about their health care. Seventy-four participants who attended consultations in five clinical areas completed structured measures of decision-making and discussed their responses during interviews. They identified a range of decisions as having being made in their consultations. People who picked particular responses on measures of participation in and satisfaction with decision-making gave varied explanations for these, not all of which were consistent with the way their responses are usually interpreted. The interview data suggest that people's evaluations of decisions to follow a particular course of action were influenced by various factors including what they focused on as the alternative, their perceptions of constraints on choices, and their assessment of how good the best possible solution was. Responses to simple structured measures of participation in and satisfaction with decision-making should be interpreted with caution. They are not reliably attributable to health care providers' actions and are thus unsuitable for performance assessment purposes.

Family communication about genetic risk: the little that is known.

Although family communication is important in clinical genetics only a small number of studies have specifically explored the passing on of genetic knowledge to family members. In addition, many of these present exploratory or tentative findings based upon small sample sizes, or data collected only a short time after testing. Nevertheless, if health professionals are to develop effective strategies to help patients' deal with communication issues, we need to know more about what actually happens in families. The aim of this commentary is to identify factors which appear to influence whether patients share information about genetic risk with relatives who are unaware of that risk, with whom they share it and how they go about it. The paper draws upon evidence and thinking from the disciplines of psychology (including family therapy), sociology, medicine and genetic counselling. It is presented under the following headings: disease factors, individual factors, family factors and sociocultural factors. It concludes by highlighting a number of key issues which are relevant for health professionals.

Length and somatic mosaicism of CAG and GGN repeats in the androgen receptor gene and the risk of prostate cancer in men with benign prostatic hyperplasia.

BACKGROUND: The most common malignancy in men worldwide is cancer of the prostate and determinants of prostate cancer (PRCa) risk remain largely unidentified. Many candidate genes may be involved in PRCa, such as those that are central to cellular growth and differentiation in the prostate gland. We analysed the polymorphic CAG and GGN repeats sequence in exon 1 of the AR gene to determine if the number of repeats might be an indicator of PRCa risk in patients with BPH. METHODS: The study evaluated 28 patients who presented with PRCa at least 6 years after the diagnosis of BPH and 56 matched patients with BPH who did not progress to PRCa over a comparable period. RESULTS: This study showed no evidence for association between the size of AR CAG and GGN repeats and the risk of the development of PRCa in patients with BPH. However, BPH patients with AR CAG instability had a 12-fold increased risk in development of PRCa. CONCLUSIONS: While independent confirmation is required in further studies, these results provide a potential tool to assist prediction strategies for this important disease.

Vitamin D receptor, HER-2 polymorphisms and risk of prostate cancer in men with benign prostate hyperplasia.

OBJECTIVE: Prostate cancer (PRCa) is one of the most common causes of cancer death in men and determinants of PRCa risk remain largely unidentified. Benign prostatic hyperplasia (BPH) is found in the majority of ageing men and has been associated with PRCa. Many candidate genes have been suggested to be involved in PRCa, such as those that are central to cellular growth and differentiation in the prostate gland. The vitamin D receptor (VDR) and HER-2 protooncogene have been shown to be involved in the regulation of cell proliferation and differentiation in prostate cells. Genetic variations of these genes could be useful to detect BPH patients that have a higher risk of developing PRCa. This study used a case-control design to assess the predictive value of 3 polymorphisms in VDR (TaqI and FokI) and HER-2 (Val655Ile) to determine the risk of developing PRCa in patients with BPH. METHODS: Polymorphisms were detected by RFLP analysis. The study evaluated 28 patients who presented with PRCa at least 6 years after the diagnosis of BPH and 56 matched patients with BPH who did not progress to PRCa over a comparable period. The study was carried out in University of Aberdeen, Foresterhill, Aberdeen, United Kingdom in the year 2002. RESULTS: Among the case group, 89% had a TT TaqI genotype, whereas 57% of control had this genotype (odds ratio [OR] = 5.16, 95% confidence interval [CI] = 1.46-18.22). A similar pattern was seen for the FokI genotype, although this was not statistically significant (OR = 2.33, 95% CI = 0.86-6.29). The frequency of the HER-2 Ile/Ile genotype was higher in cases (79%) compared to control subjects (66%), although this was not statistically significant (OR = 1.94, 95% CI = 0.67-5.63). CONCLUSION: This study shows that the VDR TaqI polymorphism is associated with a group of men with BPH who are at an increase risk of PRCa, providing a potential tool to assist prediction strategies for this important disease.

Blood pressure in relation to birth weight in twins and singleton controls matched for gestational age.

Associations between adult blood pressure and birth weight were investigated in 122 same-sex twin pairs aged 18-50 years and 86 singleton controls matched according to maternal age and parity, gender, gestational age, and current age who were recruited via an obstetric database in Aberdeen, Scotland, in 1999. Twins weighed on average 425 g less than controls at birth (p < 0.001) but did not differ significantly in adult height or systolic or diastolic blood pressure from the controls. Among controls, the differences in systolic and diastolic blood pressure per kg of difference in birth weight, adjusted for gender, gestational age, current age, body mass index, smoking, physical activity level, and alcohol intake, were -4.3 (95% confidence interval (CI): -12.8, 4.3) and -6.1 (95% CI: -10.8, -1.5) mmHg/kg, respectively. In unpaired analysis among all twins, the equivalent values were -0.1 (95% CI: -4.0, 3.8) mmHg/kg for systolic pressure and -0.4 (95% CI: -2.9, 2.2) mmHg/kg for diastolic pressure, while in within-pair analysis the values were -0.9 (95% CI: -6.4, 4.6) mmHg/kg for systolic pressure and -0.2 (95% CI: -4.1, 3.7) mmHg/kg for diastolic pressure. The results suggest that in-utero growth restriction in twins is not a major determinant of their blood pressure as adults.

A rapid method of screening for N-acetyltransferase (NAT2) phenotype by use of the WAVE DNA fragment analysis system.

N-Acetyltransferase 2 (NAT2) is involved in Phase II biotransformation of a variety of toxicants. Polymorphisms in the NAT2 gene result in a slow acetylator phenotype, which has been associated with various cancers and neurodegenerative diseases. To date most studies investigating NAT2 genotype/phenotype have adopted an RFLP approach, which is both expensive and time-consuming. Using the Wave DNA fragment analysis system, we have developed a fast and robust method of identifying two polymorphisms (C282T and T341C) of the NAT2 gene which allows identification of the most common slow acetylator alleles found in Caucasian populations: NAT2*5, NAT2*6, NAT2*7, and NAT2*14. This was done by comparing phenotype status in 126 samples genotyped by RFLP analysis and also by Wave analysis for the polymorphisms C282Tand T341C. All 126 samples analyzed by both RFLP and Wave analysis gave consistent phenotype results and 100% correlation was achieved between the two methods.

Survival in prospectively ascertained familial breast cancer: analysis of a series stratified by tumour characteristics, BRCA mutations and oophorectomy.

Dedicated clinics have been established for the early diagnosis and treatment of women at risk for inherited breast cancer, but the effects of such interventions are currently unproven. This second report on prospectively diagnosed inherited breast cancer from the European collaborating centres supports the previous conclusions and adds information on genetic heterogeneity and the effect of oophorectomy. Of 249 patients, 20% had carcinoma in situ (CIS), 54% had infiltrating cancer without spread (CaN0) and 26% had cancer with spread (CaN+). Five-year survival was 100% for CIS, 94% for CaN0 and 72% for CaN+ (p = 0.007). Thirty-six patients had BRCA1 mutations, and 8 had BRCA2 mutations. Presence of BRCA1 mutation was associated with infiltrating cancer, high grade and lack of oestrogen receptor (p < 0.05 for all 3 characteristics). For BRCA1 mutation carriers, 5-year survival was 63% vs. 91% for noncarriers (p = 0.04). For CaN0 patients, mutation carriers had 75% 5-year disease-free survival vs. 96% for noncarriers (p = 0.01). Twenty-one of the mutation carriers had undergone prophylactic oophorectomy, prior to or within 6 months of diagnosis in 13 cases. All but 1 relapse occurred in the 15 who had kept their ovaries, (p < 0.01); no relapse occurred in those who had removed the ovaries within 6 months (p = 0.04) Contralateral cancer was more frequently observed in mutation noncarriers, but this finding did not reach statistical significance. Our findings support the concept that BRCA1 cancer is biologically different from other inherited breast cancers. While current screening protocols appear satisfactory for the majority of women at risk of familial breast cancer, this may not be the case for BRCA1 mutation carriers. The observed effect of oophorectomy was striking.

CYP3A4 promoter variant is associated with prostate cancer risk in men with benign prostate hyperplasia.

Prostate cancer (PRCa) is one of the most common causes of cancer death in men and determinants of PRCa risk remain largely unidentified. Benign prostatic hyperplasia (BPH) is found in the majority of ageing men and has been linked with PRCa. CYP3A4 may influence PRCa through its role in testosterone metabolism. This nested case-control study assessed a CYP3A4 single nucleotide polymorphism as a risk factor for developing PRCa in patients with BPH. The CYP3A4 variant allele identified men with BPH who are at increased risk of progressing to PRCa (odds ratio 6.3, 95% CI 2.3-17.3), providing a potential tool to assist prediction strategies for this disease.