Reducing Asthma Attacks in Children using Exhaled Nitric Oxide as a biomarker to inform treatment strategy: a randomised trial (RAACENO).

BACKGROUND: Childhood asthma is a common condition. Currently there is no validated objective test which can be used to guide asthma treatment in children. This study tests the hypothesis that the addition of fractional exhaled nitric oxide (FENO) monitoring in addition to standard care reduces the number of exacerbations (or attacks) in children with asthma. METHODS: This is a multi-centre, randomised controlled study. Children will be included of age 6-16 years who have a diagnosis of asthma, currently use inhaled corticosteroids (ICSs) and have had an exacerbation in the previous 12 months. Exclusion criteria include being unable to provide FENO measurement at baseline assessment, having another chronic respiratory condition and being currently treated with maintenance oral steroids. Participants will be recruited in both primary and secondary care settings and will be randomised to either receive asthma treatment guided by FENO plus symptoms (FENO group) or asthma treatment guided by symptoms only (standard care group). Within the FENO group, different treatment decisions will be made dependent on changes in FENO. Participants will attend assessments 3, 6, 9 and 12 months post randomisation. The primary outcome is asthma exacerbation requiring prescription and/or use of an oral corticosteroid over 12 months as recorded by the participant/parent or in general practitioner records. Secondary outcomes include time to first attack, number of attacks, asthma control score and quality of life. Adherence to ICS treatment is objectively measured by an electronic logging device. Participants are invited to participate in a "phenotyping" assessment where skin prick reactivity and bronchodilator response are determined and a saliva sample is collected for DNA extraction. Qualitative interviews will be held with participants and research nurses. A health economic evaluation will take place. DISCUSSION: This study will evaluate whether FENO can provide an objective index to guide and stratify asthma treatment in children. TRIAL REGISTRATION: ISRCTN, ISRCTN67875351. Registered on 12 April 2017. Prospectively registered.

Reduction in colposcopy workload and associated clinical activity following human papillomavirus (HPV) catch-up vaccination programme in Scotland: an ecological study.

OBJECTIVE: To measure patterns of clinical activity at colposcopy before and after vaccinated women entered the Scottish Cervical Screening Programme (SCSP). DESIGN: Population-based observational study using nationally collected data. SETTING: Scottish colposcopy clinics. SAMPLE: All women with a date of birth on or after 1 January 1985 who attended colposcopy in Scotland between 2008 and 2014. METHODS: Routinely collected data from the Scottish National Colposcopy Clinical Information Audit System (NCCIAS) were extracted, including: referral criteria, referral cervical cytology, colposcopic findings, clinical procedures, and histology results. Analysis was restricted to those referred to colposcopy at age 20 or 21 years. MAIN OUTCOME MEASURES: Referral criteria, positive predictive value of colposcopy, default rates, and rates of cervical biopsies and treatments. RESULTS: A total of 7372 women referred for colposcopy at age 20 or 21 years were identified. There was a downward trend in the proportion of those referred with abnormal cytology (2008/9, 91.0%; 2013/14, 90.3%; linear trend P = 0.03). Women were less likely to have diagnostic or therapeutic interventions. The proportion with no biopsy (2008/9, 19.5%; 2013/14, 26.9%; linear trend P < 0.0001) and no treatment (2008/9, 74.9%; 2013/14, 91.8%; linear trend P < 0.0001) increased over the period of observation. CONCLUSIONS: A reduction in clinical activity related to abnormal screening referrals is likely to be associated with the human papillomavirus (HPV) catch-up immunisation programme. Referral criteria and the service provision of colposcopy needs to be planned carefully, taking account of the increasing number of women who have been immunised against HPV that will be entering cervical screening programmes worldwide. TWEETABLE ABSTRACT: Colposcopy referral criteria and service planning need attention following HPV immunisation programme.

Psychosocial morbidity in women with abnormal cervical cytology managed by cytological surveillance or initial colposcopy: longitudinal analysis from the TOMBOLA randomised trial.

OBJECTIVE: To compare psychosocial outcomes (follow-up related worries and satisfaction with follow-up related information and support) over 30 months of two alternative management policies for women with low-grade abnormal cervical cytology. METHODS: Women aged 20-59 years with low-grade cytological abnormalities detected in the National Health Service Cervical Screening Programme were randomised to cytological surveillance or initial colposcopy. A total of 3399 women who completed psychosocial questionnaires at recruitment were invited to complete questionnaires at 12, 18, 24 and 30 months. Linear mixed models were used to investigate differences between arms in the two psychosocial outcomes. Each outcome had a maximum score of 100, and higher scores represented higher psychosocial morbidity. RESULTS: On average, over 30 months, women randomised to colposcopy scored 2.5 points (95%CI -3.6 to -1.3) lower for follow-up related worries than women randomised to cytological surveillance. Women in the colposcopy arm also scored significantly lower for follow-up related satisfaction with information and support (-2.4; -3.3 to -1.4) over 30 months. For both outcomes, the average difference between arms was greatest at 12th- and 18th-month time points. These differences remained when the analysis was stratified by post-school education. CONCLUSIONS: Women with low-grade cytology, irrespective of their management, have substantial initial psychosocial morbidity that reduces over time. Implementation of newer screening strategies, which include surveillance, such as primary HPV screening, need to consider the information and support provided to women. © 2016 The Authors. Psycho-Oncology published by John Wiley & Sons Ltd.

Behavioural recovery after treatment for varicose veins.

BACKGROUND: The aim of this study was to assess behavioural recovery from the patient's perspective as a prespecified secondary outcome in a multicentre parallel-group randomized clinical trial comparing ultrasound-guided foam sclerotherapy (UGFS), endovenous laser ablation (EVLA) and surgery for the treatment of primary varicose veins. METHODS: Participants were recruited from 11 UK sites as part of the CLASS trial, a randomized trial of UGFS, EVLA or surgery for varicose veins. Patients were followed up 6 weeks after treatment and asked to complete the Behavioural Recovery After treatment for Varicose Veins (BRAVVO) questionnaire. This is a 15-item instrument that covers eight activity behaviours (tasks or actions an individual is capable of doing in an idealized situation) and seven participation behaviours (what the individual does in an everyday, real-world situation) that were identified to be important from the patient's perspective. RESULTS: A total of 798 participants were recruited. Both UGFS and EVLA resulted in a significantly quicker recovery compared with surgery for 13 of the 15 behaviours assessed. UGFS was superior to EVLA in terms of return to full-time work (hazard ratio 1·43, 95 per cent c.i. 1·11 to 1·85), looking after children (1·45, 1·04 to 2·02) and walks of short (1·48, 1·19 to 1·84) and longer (1·32, 1·05 to 1·66) duration. CONCLUSION: Both UGFS and EVLA resulted in more rapid recovery than surgery, and UGFS was superior to EVLA for one-quarter of the behaviours assessed. The BRAVVO questionnaire has the potential to provide important meaningful information to patients about their early recovery and what they may expect to be able to achieve after treatment.

A normal colposcopy examination fails to provide psychological reassurance for women who have had low-grade abnormal cervical cytology.

OBJECTIVE: Worldwide, each year, large numbers of women are referred for colposcopy following low-grade abnormal cervical cytology. Many have no visible abnormality on examination. The risk of cervical intra-epithelial neoplasia grade 2/3 (CIN2/3) in these women is low. It is unknown whether, for women, a normal colposcopy resolves the anxiety which often follows the receipt of an abnormal cytology result. We investigated the prevalence of adverse psychological outcomes over 30 months following a normal colposcopy. METHODS: This cohort study was nested within the UK TOMBOLA randomized controlled trial. Women aged 20-59 years, with recent low-grade cytology, who had a satisfactory colposcopy examination and normal transformation zone, completed the Hospital Anxiety and Depression Scale (HADS) and Process Outcome Specific Measure (POSM) at recruitment and during follow-up (12, 18, 24 and 30 months post-recruitment). Outcomes included percentages reporting significant anxiety (HADS anxiety subscale score ≥11), significant depression (HADS depression subscale score ≥8) or worries about the result of the next cytology test, cervical cancer, having sex, future fertility and general health at each time point (point prevalence) and during follow-up (cumulative prevalence). RESULTS: The study included 727 women. All psychological measures (except depression) had high prevalence at recruitment, falling substantially by 12 months. During follow-up, the cumulative prevalence of significant anxiety was 27% and significant depression was 21%. The most frequently reported worry was that the next cytology test would be abnormal (cumulative prevalence of 71%; point prevalence of ≥50% at 12 and 18 months). The cumulative prevalence values of worries about cervical cancer, having sex and future fertility were 33%, 20% and 16%, respectively. CONCLUSIONS: For some women who have low-grade cytology, a normal colposcopy does not appear to provide psychological reassurance.

Management of women with low grade cytology: how reassuring is a normal colposcopy examination?

OBJECTIVES: To determine the rate of cervical intraepithelial neoplasia grade 2 (CIN2+) in women with low grade cervical cytology and a normal colposcopy examination over 3 years of follow-up. DESIGN: Cohort study within a randomised controlled trial. SETTING: NHS Cervical Screening Programmes in Grampian, Tayside and Nottingham. POPULATION: Eight hundred and eighty-four women aged 20-59 years with borderline nuclear abnormalities (BNA) or mild dyskaryosis with a normal and adequate colposcopy examination. METHODS: Samples at baseline were tested for 14 high-risk (Hr) types using GP5+6+ methodology and for HPV 16 and 18 using type-specific primers. Women were followed up post-colposcopy by cervical cytology at 6-month intervals in primary care. After 3 years, women were invited for an exit colposcopy examination and underwent LLETZ if any colposcopic abnormality was identified. MAIN OUTCOME MEASURES: Absolute and relative risks of CIN2+ during follow-up and/or at exit colposcopy. RESULTS: The median age was 36 years. The absolute risk of developing CIN2+ within 3 years was 1.86 per 100 woman years and for CIN3+, 0.64 per 100 woman years. One microinvasive cancer was identified. The relative risk (RR) was highest for women with initial mild dyskaryosis who were HrHPV-positive (RR 5.86, 95% confidence interval 2.53-13.56) compared with women with BNA who were HrHPV-negative. CONCLUSION: For women with low grade cervical cytology, the risk of a high grade CIN within 3 years of a normal colposcopy examination is low. Women can be reassured that, even with a positive HPV test, the risk of developing CIN2 or worse is sufficiently low to return to the routine 3-year recall.

Cost-effectiveness of ultrasound-guided foam sclerotherapy, endovenous laser ablation or surgery as treatment for primary varicose veins from the randomized CLASS trial.

BACKGROUND: The treatment of patients with varicose veins constitutes a considerable workload and financial burden to the National Health Service. This study aimed to assess the cost-effectiveness of ultrasound-guided foam sclerotherapy (UGFS) and endovenous laser ablation (EVLA) compared with conventional surgery as treatment for primary varicose veins. METHODS: Participant cost and utility data were collected alongside the UK CLASS multicentre randomized clinical trial, which compared EVLA, surgery and UGFS. Regression methods were used to estimate the effects of the alternative treatments on costs to the health service and quality-adjusted life-years (QALYs) at 6 months. A Markov model, incorporating available evidence on clinical recurrence rates, was developed to extrapolate the trial data over a 5-year time horizon. RESULTS: Compared with surgery at 6 months, UGFS and EVLA reduced mean costs to the health service by £655 and £160 respectively. When additional overhead costs associated with theatre use were included, these cost savings increased to £902 and £392 respectively. UGFS produced 0·005 fewer QALYs, whereas EVLA produced 0·011 additional QALYs. Extrapolating to 5 years, EVLA was associated with increased costs and QALYs compared with UGFS (costing £3640 per QALY gained), and generated a cost saving (£206-439) and QALY gain (0·078) compared with surgery. Applying a ceiling willingness-to-pay ratio of £20 000 per QALY gained, EVLA had the highest probability (78·7 per cent) of being cost-effective. CONCLUSION: The results suggest, for patients considered eligible for all three treatment options, that EVLA has the highest probability of being cost-effective at accepted thresholds of willingness to pay per QALY.

Clinical and economic evaluation of laparoscopic surgery compared with medical management for gastro-oesophageal reflux disease: 5-year follow-up of multicentre randomised trial (the REFLUX trial).

BACKGROUND: Despite promising evidence that laparoscopic fundoplication provides better short-term relief of gastro-oesophageal reflux disease (GORD) than continued medical management, uncertainty remains about whether benefits are sustained and outweigh risks. OBJECTIVE: To evaluate the long-term clinical effectiveness, cost-effectiveness and safety of laparoscopic surgery among people with GORD requiring long-term medication and suitable for both surgical and medical management. DESIGN: Five-year follow-up of a randomised trial (with parallel non-randomised preference groups) comparing a laparoscopic surgery-based policy with a continued medical management policy. Cost-effectiveness was assessed alongside the trial using a NHS perspective for costs and expressing health outcomes in terms of quality-adjusted life-years (QALYs). SETTING: Follow-up was by annual postal questionnaire and selective hospital case notes review; initial recruitment in 21 UK hospitals. PARTICIPANTS: Questionnaire responders among the 810 original participants. At entry, all had documented evidence of GORD and symptoms for > 12 months. Questionnaire response rates (years 1-5) were from 89.5% to 68.9%. INTERVENTIONS: Three hundred and fifty-seven participants were recruited to the randomised comparison (178 randomised to surgical management and 179 randomised to continued medical management) and 453 to the preference groups (261 surgical management and 192 medical management). The surgeon chose the type of fundoplication. MAIN OUTCOME MEASURES: Primary: disease-specific outcome measure (the REFLUX questionnaire); secondary: Short Form questionnaire-36 items (SF-36), European Quality of Life-5 Dimensions (EQ-5D), NHS resource use, reflux medication, complications. RESULTS: The randomised groups were well balanced. By 5 years, 63% in the randomised surgical group and 13% in the randomised medical management group had received a total or partial wrap fundoplication (85% and 3% in the preference groups), with few perioperative complications and no associated deaths. At 1 year (and 5 years) after surgery, 36% (41%) in the randomised surgical group - 15% (26%) of those who had surgery - were taking proton pump inhibitor medication compared with 87% (82%) in the randomised medical group. At each year, differences in the REFLUX score significantly favoured the randomised surgical group (a third of a SD; p< 0.01 at 5 years). SF-36 and EQ-5D scores also favoured surgery, but differences attenuated over time and were generally not statistically significant at 5 years. The worse the symptoms at trial entry, the larger the benefit observed after surgery. Those randomised to medical management who subsequently had surgery had low baseline scores that markedly improved after surgery. Following fundoplication, 3% had surgical treatment for a complication and 4% had subsequent reflux-related operations - most often revision of the wrap. Dysphagia, flatulence and inability to vomit were similar in the two randomised groups. The economic analysis indicated that surgery was the more cost-effective option for this patient group. The incremental cost-effectiveness ratio for surgery in the base case was £7028 per additional QALY; these findings were robust to changes in approaches and assumptions. The probability of surgery being cost-effective at a threshold of £20,000 per additional QALY was > 0.80 for all analyses. CONCLUSIONS: After 5 years, laparoscopic fundoplication continues to provide better relief of GORD symptoms with associated improved health-related quality of life. Complications of surgery were uncommon. Despite being initially more costly, a surgical policy is highly likely to be cost-effective. TRIAL REGISTRATION: Current Controlled Trials ISRCTN15517081. FUNDING: This project was funded by the NIHR Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 17, No. 22. See the HTA programme website for further project information.

Minimal access surgery compared with medical management for gastro-oesophageal reflux disease: five year follow-up of a randomised controlled trial (REFLUX).

OBJECTIVES: To determine the long term clinical effectiveness of laparoscopic fundoplication as an alternative to drug treatment for chronic gastro-oesophageal reflux disease (GORD). DESIGN: Five year follow-up of multicentre, pragmatic randomised trial (with parallel non-randomised preference groups). SETTING: Initial recruitment in 21 UK hospitals. PARTICIPANTS: Responders to annual questionnaires among 810 original participants. At entry, all had had GORD for >12 months. INTERVENTION: The surgeon chose the type of fundoplication. Medical therapy was reviewed and optimised by a specialist. Subsequent management was at the discretion of the clinician responsible for care, usually in primary care. MAIN OUTCOME MEASURES: Primary outcome measure was self reported quality of life score on disease-specific REFLUX questionnaire. Other measures were health status (with SF-36 and EuroQol EQ-5D questionnaires), use of antireflux medication, and complications. RESULTS: By five years, 63% (112/178) of patients randomised to surgery and 13% (24/179) of those randomised to medical management had received a fundoplication (plus 85% (222/261) and 3% (6/192) of those who expressed a preference for surgery and for medical management). Among responders at 5 years, 44% (56/127) of those randomised to surgery were taking antireflux medication versus 82% (98/119) of those randomised to medical management. Differences in the REFLUX score significantly favoured the randomised surgery group (mean difference 8.5 (95% CI 3.9 to 13.1), P<0.001, at five years). SF-36 and EQ-5D scores also favoured surgery, but were not statistically significant at five years. After fundoplication, 3% (12/364) had surgical treatment for a complication and 4% (16) had subsequent reflux-related operations-most often revision of the wrap. Long term rates of dysphagia, flatulence, and inability to vomit were similar in the two randomised groups. CONCLUSIONS: After five years, laparoscopic fundoplication continued to provide better relief of GORD symptoms than medical management. Adverse effects of surgery were uncommon and generally observed soon after surgery. A small proportion had re-operations. There was no evidence of long term adverse symptoms caused by surgery. TRIAL REGISTRATION: Current Controlled Trials ISRCTN15517081.

Lifestyle and socio-demographic factors associated with high-risk HPV infection in UK women.

The world age-standardised prevalence of high-risk HPV (hrHPV) infection among 5038 UK women aged 20-59 years, with a low-grade smear during 1999-2002, assessed for eligibility for TOMBOLA (Trial Of Management of Borderline and Other Low-grade Abnormal smears) was 34.2%. High-risk HPV prevalence decreased with increasing age, from 61% at ages 20-24 years to 14-15% in those over 50 years. The age-standardised prevalence was 15.1, 30.7 and 52.7%, respectively, in women with a current normal, borderline nuclear abnormalities (BNA) and mild smear. In overall multivariate analyses, tertiary education, previous pregnancy and childbirth were associated with reduced hrHPV infection risk. Risk of infection was increased in non-white women, women not married/cohabiting, hormonal contraceptives users and current smokers. In stratified analyses, current smear status and age remained associated with hrHPV infection. Data of this type are relevant to the debate on human papillomavirus (HPV) testing in screening and development of HPV vaccination programmes.

Reasons for participation and non-participation in a randomized controlled trial: postal questionnaire surveys of women eligible for TOMBOLA (Trial Of Management of Borderline and Other Low-Grade Abnormal smears).

BACKGROUND: Better understanding of motivators for, and barriers to, participation in randomized controlled trials (RCTs) in different study populations and settings has the potential to improve participation of historically under-represented groups (eg, women) in future trials. PURPOSE: To investigate reasons why women agreed, or declined, to participate in a RCT. METHODS: In two postal questionnaire-based studies, we investigated women's reasons for participation or non-participation in TOMBOLA, a RCT comparing management policies for low-grade cervical abnormalities. Four-hundred and ninety-two TOMBOLA participants (response rate 56%) completed questionnaires on reasons for participation. One-hundred and thiry-seven women (38%) who declined TOMBOLA participation completed questionnaires on reasons for this. RESULTS: Eighty percent of women reported that one of their reasons for attending their TOMBOLA recruitment appointment was worries about their smear result. Ninety-four percent participated in the RCT because it was a worthwhile contribution to the cervical screening programme and other women; for 70% this was the most important reason. These proportions did not vary by socio-demographic factors. Thirty-two percent thought participation would result in better care. The most common reason for non-participation was preference for follow-up from the woman's GP. Logistical issues (eg, inconvenient appointments, travel time, arranging time off work or child-care) were commonly cited. Fourteen percent were too frightened to participate; this was unrelated to the grade of the recruitment smear. LIMITATIONS: Response rates were not high, but there was little evidence of response bias. Structured questionnaires were used. CONCLUSIONS: Future research should address how best to deliver information to ensure different social groups appreciate potential benefits of RCT participation and provide reassurance regarding fears about participation. Simple strategies (eg, appealing to the altruism of potential participants or offering flexible recruitment clinic locations and times) might enhance RCT recruitment rates. This in turn would ensure best use of research resources thus bringing the greatest benefits to participants and the population.

Psychological effects of a low-grade abnormal cervical smear test result: anxiety and associated factors.

Receipt of an abnormal cervical smear result often generates fear and confusion and can have a negative impact on a woman's well-being. Most previous studies have focussed on high-grade abnormal smears. This study describes the psychological and psychosocial effects, on women, of having received a low-grade abnormal smear result. Over 3500 women recruited to TOMBOLA (Trial Of Management of Borderline and Other Low-grade Abnormal smears) participated in this study. Anxiety was assessed using the Hospital Anxiety and Depression Scale (HADS) at recruitment. Socio-demographic and lifestyle factors, locus of control and factors associated with the psychosocial impact of the abnormal smear result were also assessed. Women reported anxiety levels consistent with those found in previous studies of women with high-grade smear results. Women at highest risk of anxiety were younger, had children, were current smokers, or had the highest levels of physical activity. Interventions that focus particularly on women's understanding of smear results and pre-cancer, and/or directly address their fears about cancer, treatment and fertility might provide the greatest opportunity to reduce the adverse psychosocial impact of receiving a low-grade abnormal cervical smear result.

Developing a questionnaire to measure the psychosocial impact of an abnormal cervical smear result and its subsequent management: the TOMBOLA (Trial of Management of Borderline and Other Low-grade Abnormal Smears) trial.

This paper describes the process of developing and testing a new questionnaire, Process Outcome Specific Measure (POSM), including an assessment of its content validity and reliability. The questionnaire was developed within the context of Trial Of Management of Borderline and Other Low-grade Abnormal smears (TOMBOLA) to assess the psychosocial impact of a low-grade abnormal cervical smear result and the subsequent management. A literature search, focus groups and thorough pre-testing involving experts and patients resulted in a short (15-item), easily completed and understood questionnaire. Questions address issues including cancer, health, fertility and sexual concerns. Repeatability was assessed in 110 TOMBOLA recruits using weighted k; all but one of the questions showed levels of reliability near to, or above, 0.5. Cronbach's standardised alpha was 0.73, indicating acceptable internal consistency. Each POSM item was correlated with the anxiety and depression sub-scales of the Hospital Anxiety Depression Scale (HADS). All except one of the questions correlated more highly with the total POSM score than with the HADS sub-scales thus indicating discriminant validity. The POSM will enable comparison of the alternative management policies for low-grade cervical smears in terms of the benefits (or otherwise) perceived by the women managed by these policies.

Cytochrome P-450 1A1 gene polymorphisms and risk of breast cancer: a HuGE review.

Cytochrome P-450 (CYP) 1A1 plays a key role in phase I metabolism of polycyclic aromatic hydrocarbons and in estrogen metabolism. It is expressed predominantly in extrahepatic tissues, including the breast. Four CYP1A1 gene polymorphisms (3801T --> C, Ile462Val, 3205T --> C, and Thr461Asp) have been studied in relation to breast cancer. The 3801C variant is more common than the Val variant. Both variants occur more frequently in Asians than in White populations. The 3205T --> C polymorphism has been observed in African Americans only. Little data are available on the geographic/ethnic distribution of the Thr461Asp polymorphism. The functional significance of the polymorphisms is unclear. In 17 studies, no consistent association between breast cancer and CYP1A1 genotype was found. Meta-analysis found no significant risk for the genotypes 1) 3801C/C (relative risk (RR) = 0.97, 95% confidence interval (CI): 0.52, 1.80) or 3801T/C (RR = 0.91, 95% CI: 0.70, 1.19) versus 3801T/T, 2) Val/Val (RR = 1.04, 95% CI: 0.63, 1.74) or Ile/Val (RR = 0.92, 95% CI: 0.76, 1.10) versus Ile/Ile, or 3) Asp/Asp (RR = 0.95, 95% CI: 0.20, 4.49) or Thr/Asp (RR = 1.12, 95% CI: 0.87, 1.43) versus Thr/Thr. Future studies should explore possible interactions between CYP1A1 and sources of polycyclic aromatic hydrocarbons, markers of estrogen exposure, other lifestyle factors influencing hormonal levels, and other genes involved in polycyclic aromatic hydrocarbon metabolism or hormonal biosynthesis.

CYP17 gene polymorphisms: prevalence and associations with hormone levels and related factors. a HuGE review.

The cytochrome P-450c17alpha (CYP17 ) gene, located on chromosome 10q24.3, encodes the enzyme cytochrome P-450c17alpha, which functions at key branch points in steroid hormone biosynthesis. Three polymorphisms have been described, but only the single base-pair change in the 5'-untranslated region (5'-UTR) has been investigated to any great extent. In single studies, the variant was associated with reduced messenger RNA level in ovarian cells but not with messenger RNA level in breast tissue. Homozygosity for the 5'-UTR variant is most common in East Asian (32%) and Japanese (22%) populations and is less common among White (mainly European and North American (14%)) and Black (mainly African-American (13%)) populations, but selection biases are likely to have affected these frequency estimates. Genotype appears to influence circulating estrogen levels in premenopausal women, while studies of relations with hormone levels in men have produced inconclusive results. However, relatively few studies have been conducted. Seven of 11 retrospective studies suggested a modest association between genotype and age at menarche. Random error in recall of age at menarche is likely to have attenuated this relation. Associations between genotype and postmenopausal estrogen use and bone mass have been observed in single studies. Further investigation of relations between genotype and hormone levels, exogenous hormone use, and markers of hormonal status may advance understanding of hormonally mediated diseases.

Folate and breast cancer: the role of polymorphisms in methylenetetrahydrofolate reductase (MTHFR).

Evidence is growing that low folate status may be a factor in the aetiology of several cancers, including breast cancer. The methylenetetrahydrofolate reductase gene (MTHFR), which has a key role in folate metabolism, is polymorphic. We report a case-control study of two functional polymorphisms in MTHFR, dietary folate intake and breast cancer. Sixty-two cases with invasive breast cancer and sixty-six general practice controls participated. Women reporting the highest dietary folate intake had non-significantly reduced breast cancer risk (odds ratio (OR) = 0.49, 95% confidence interval (CI) 0.20-1.20). Risk was significantly lower for the 1298CC genotype compared to AA (OR = 0.24, 95% CI 0.06-0.97). Relative to compound wild-type subjects, compound heterozygotes had moderately reduced risk (OR = 0.47, 95% CI 0.11-1.92) and homozygote variants (677TT and/or 1298CC) greater reduced risk (OR = 0.26, 95% CI 0.07-0.96); the trend was statistically significant. Patterns in risk with regard to genotype and folate combinations are broadly similar those reported for colorectal neoplasia. The roles of MTHFR and folate in breast cancer aetiology are likely to be complex.

N-acetyltransferase polymorphisms and colorectal cancer: a HuGE review.

The two expressed genes coding for N-acetyltransferase (NAT) activity, NAT1 and NAT2, are located on chromosome 8 at 8p21.3-23.1 and are polymorphic. Both enzymes are capable of N-acetylation, O-acetylation, and N,O-acetylation and are implicated in the activation and detoxification of known carcinogens. Single base-pair substitutions in NAT2 tend to occur in combination with other substitutions within the gene. As yet, less work has been done to characterize NAT1 allelic variants. Various methods for the detection of the reported polymorphisms exist. It is important to select a method that is appropriate to the population being studied. The functional significance of many NAT allelic variants has not been determined. Geographic and ethnic variation in the frequency of NAT2 genotypes associated with fast or intermediate acetylation has been observed. Insufficient data for NAT1 genotypes are available to reveal a clear geographic pattern. No consistent association has been found between acetylator phenotype or genotype and colorectal cancer. The lack of consistency can in part be accounted for by methodological factors, including limited statistical power. Possible interactions between the NAT genes and either environmental exposures or other polymorphic genes encoding xenobiotic metabolizing enzymes have been investigated in only a minority of these studies, and these studies have lacked statistical power to detect interactions.

Glutathione S-transferase polymorphisms and colorectal cancer: a HuGE review.

The genes glutathione S-transferase M1 (GSTM1) (chromosome 1p13.3) and glutathione S-transferase T1 (GSTT1) (22q11.2) code for cytosolic enzymes glutathione S-transferase (GST)-mu and GST-theta, respectively, which are involved in phase 2 metabolism. Both genes may be deleted. There is geographic and ethnic variation in genotype frequencies for both genes. In developed countries, colorectal cancer is the second most common cancer. Colorectal cancer has been inconsistently associated with polycyclic aromatic hydrocarbons in diet and tobacco. Because GST enzymes are involved in polycyclic aromatic hydrocarbon metabolism, it has been postulated that genotype may modify colorectal cancer risk associated with polycyclic aromatic hydrocarbon exposure. No consistent associations between GSTM1 or GSTT1 genotype and colorectal cancer have been observed. However, most studies have methodological limitations. Few have investigated gene-environment interactions. No interactions between GSTM1 or GSTT1 genotype and smoking and colorectal cancer risk have been reported. One polyp study suggests an interaction between GSTM1 genotype and smoking. Two studies suggest increased disease risk in subjects with high meat intake and GST nonnull genotype, contrary to the underlying hypothesis. One study suggests a strong inverse relation between colorectal adenomas and broccoli consumption, particularly in subjects who are GSTM1 null. These finding require confirmation. Methods for determining GSTM1 and GSTT1 genotype are well established. Population testing is not currently justified.