Association between Mediterranean diet and metal mixtures concentrations in pregnant people from the New Hampshire Birth Cohort Study.

Diet is a primary source of nutrients but also toxic metal exposure. In pregnancy, balancing essential metal exposure while reducing non-essential ones is vital for fetal and maternal health. However, the effect of metal mixtures from diets like the Mediterranean, known for health benefits, remains unclear. This study aimed to explore the association between Mediterranean diet adherence and metals exposure, both individually and as mixtures. The study involved 907 pregnant participants from the New Hampshire Birth Cohort Study. We calculated the relative Mediterranean diet score (rMED) through a validated food frequency questionnaire, which includes 8 traditional Mediterranean dietary components. Also, at ~24-28 weeks of gestation, we used ICP-MS to measure speciation of Al, Cd, Co, Cu, Fe, Hg, Mo, Ni, Sb, Se, Sn, Zn, and As in urine, as well as Pb, Hg, As, Ni, and Se in toenails. We used multiple linear regression and Weighted Quantile Sum regression to analyze the association between rMED and metal mixtures. The models were adjusted for age, pre-pregnancy BMI, smoking during pregnancy, and educational level. High adherence to the Mediterranean diet was associated with increased urinary Al (® = 0.26 (95 % confidence interval (CI) = 0.05; 0.46)), Cd (ß = 0.12 (95%CI = 0.00; 0.24)), Mo (ß = 0.10 (95%CI = 0.00; 0.20)), and AsB (ß = 0.88 (95%CI = 0.49; 1.27)) as well as toenail Hg (ß = 0.44 (95%CI = 0.22; 0.65)), Ni (ß = 0.37 (95%CI = 0.06; 0.67)), and Pb (ß = 0.22 (95%CI = 0.03; 0.40)) compared to those with low adherence. The intake of fruits and nuts, fish and seafood, legumes, cereals, meat, and olive oil were found to be related to the metal biomarkers within the rMED. In conclusion, the Mediterranean diet enhances essential metal intake but may also increase exposure to harmful ones.

Arsenic exposure in relation to apple consumption among infants in the New Hampshire Birth Cohort Study.

Infants and young children commonly consume apple-based products, which may contain high concentrations of inorganic arsenic (iAs). As yet, iAs exposure from ingesting apple products has not been well-characterized in early childhood. Therefore, we investigated the association between urinary arsenic concentrations and intake of apple products in one-year-old infants participating in the New Hampshire Birth Cohort Study. A three-day food diary prior to collection of a spot urine sample was used to determine infant's consumption of apple products. The sum of urinary iAs, monomethylarsonic acid, and dimethylarsinic acid, referred to as ΣAs, was used to estimate iAs exposure. A total of 242 infants had urinary arsenic speciation analyzed without indication of fish/seafood consumption (urinary arsenobetaine < 1 µg/L) and with a completed three-day food diary. Of these, 183 (76%) infants ate apples or products containing apple. The geometric mean urinary ΣAs among the 59 infants who did not consume any type of apple product was 2.78 µg/L as compared to 2.38, 2.46, 2.28, and 2.73 µg/L among infants who exclusively consumed apple juice (n = 30), apple puree (n = 67), apples as whole fruit (n = 20) or products mixed with apples (n = 21), respectively. Differences in urinary ΣAs associated with apple consumption were not statistically significant in generalized linear models adjusted for urine dilution, rice consumption, and household water arsenic. Thus, while infants in our study frequently consumed apples and apple products, we did not find evidence that it increased iAs exposure.

Specific class of intrapartum antibiotics relates to maturation of the infant gut microbiota: a prospective cohort study.

OBJECTIVE: To evaluate the potential impact of intrapartum antibiotics, and their specific classes, on the infant gut microbiota in the first year of life. DESIGN: Prospective study of infants in the New Hampshire Birth Cohort Study (NHBCS). SETTINGS: Rural New Hampshire, USA. POPULATION OR SAMPLE: Two hundred and sixty-six full-term infants from the NHBCS. METHODS: Intrapartum antibiotic use during labour and delivery was abstracted from medical records. Faecal samples collected at 6 weeks and 1 year of age were characterised by 16S rRNA sequencing, and metagenomics analysis in a subset of samples. EXPOSURES: Maternal exposure to antibiotics during labour and delivery. MAIN OUTCOME MEASURE: Taxonomic and functional profiles of faecal samples. RESULTS: Infant exposure to intrapartum antibiotics, particularly to two or more antibiotic classes, was independently associated with lower microbial diversity scores as well as a unique bacterial community at 6 weeks (GUnifrac, P = 0.02). At 1 year, infants in the penicillin-only group had significantly lower α diversity scores than infants not exposed to intrapartum antibiotics. Within the first year of life, intrapartum exposure to penicillins was related to a significantly lower increase in several taxa including Bacteroides, use of cephalosporins was associated with a significantly lower rise over time in Bifidobacterium and infants in the multi-class group experienced a significantly higher increase in Veillonella dispar. CONCLUSIONS: Our findings suggest that intrapartum antibiotics alter the developmental trajectory of the infant gut microbiome, and specific antibiotic types may impact community composition, diversity and keystone immune training taxa. TWEETABLE ABSTRACT: Class of intrapartum antibiotics administered during delivery relates to maturation of infant gut microbiota.

Epigenetics as a mechanism linking developmental exposures to long-term toxicity.

A variety of experimental and epidemiological studies lend support to the Developmental Origin of Health and Disease (DOHaD) concept. Yet, the actual mechanisms accounting for mid- and long-term effects of early-life exposures remain unclear. Epigenetic alterations such as changes in DNA methylation, histone modifications and the expression of certain RNAs have been suggested as possible mediators of long-term health effects of environmental stressors. This report captures discussions and conclusions debated during the last Prenatal Programming and Toxicity meeting held in Japan. Its first aim is to propose a number of criteria that are critical to support the primary contribution of epigenetics in DOHaD and intergenerational transmission of environmental stressors effects. The main criteria are the full characterization of the stressors, the actual window of exposure, the target tissue and function, the specificity of the epigenetic changes and the biological plausibility of the linkage between those changes and health outcomes. The second aim is to discuss long-term effects of a number of stressors such as smoking, air pollution and endocrine disruptors in order to identify the arguments supporting the involvement of an epigenetic mechanism. Based on the developed criteria, missing evidence and suggestions for future research will be identified. The third aim is to critically analyze the evidence supporting the involvement of epigenetic mechanisms in intergenerational and transgenerational effects of environmental exposure and to particularly discuss the role of placenta and sperm. While the article is not a systematic review and is not meant to be exhaustive, it critically assesses the contribution of epigenetics in the long-term effects of environmental exposures as well as provides insight for future research.

Risk of basal cell carcinoma in a randomized clinical trial of aspirin and folic acid for the prevention of colorectal adenomas.

BACKGROUND: Aspirin may reduce the risk of several types of cancer. OBJECTIVES: To evaluate if folic acid is associated with risk of basal cell carcinoma (BCC). METHODS: BCC incidence was evaluated in a randomized, double-blind, placebo-controlled clinical trial of aspirin (81 mg daily or 325 mg daily for ~3 years) and/or folic acid (1 mg daily for ~6 years) for the prevention of colorectal adenomas among 1121 participants with a previous adenoma. BCC was confirmed by blinded review of pathology reports. RESULTS: One hundred and four of 958 non-Hispanic white participants were diagnosed with BCC over a median follow-up of 13·5 years. Cumulative incidence of BCC was 12% [95% confidence interval (CI) 7-17] for placebo, 16% (95% CI 11-21) for 81 mg aspirin daily and 15% (95% CI 10-20) for 325 mg aspirin daily [hazard ratio (HR) for any aspirin 1·45 (95% CI 0·93-2·26); HR for 81 mg daily 1·57 (95% CI 0·96-2·56); HR for 325 mg daily 1·33 (95% CI 0·80-2·20)]. BCC risk was higher with aspirin use in those without previous skin cancer but lower with aspirin use in those with previous skin cancer (Pinteraction = 0·02 for 81 mg aspirin daily; Pinteraction = 0·03 for 325 mg aspirin daily). Folic acid supplementation was unrelated to BCC incidence (HR 0·85; 95% CI 0·57-1·27). CONCLUSIONS: Neither aspirin nor folic acid treatment had a statistically significant effect on risk of BCC. Subgroup analysis suggested that chemopreventive effects of nonsteroidal anti-inflammatory drugs may be specific to those at high risk for BCC.

Review of processing and analysis methods for DNA methylation array data.

The promise of epigenome-wide association studies and cancer-specific somatic DNA methylation changes in improving our understanding of cancer, coupled with the decreasing cost and increasing coverage of DNA methylation microarrays, has brought about a surge in the use of these technologies. Here, we aim to provide both a review of issues encountered in the processing and analysis of array-based DNA methylation data and a summary of the advantages of recent approaches proposed for handling those issues, focusing on approaches publicly available in open-source environments such as R and Bioconductor. We hope that the processing tools and analysis flowchart described herein will facilitate researchers to effectively use these powerful DNA methylation array-based platforms, thereby advancing our understanding of human health and disease.

Hearing loss and heavy metal toxicity in a Nicaraguan mining community: audiological results and case reports.

We measured fingernail metal levels, Békésy-type pure-tone thresholds and distortion product otoacoustic emission (DPOAE) levels in 59 subjects residing in the gold mining community of Bonanza, Nicaragua. Auditory testing revealed widespread hearing loss in the cohort. Nail metal concentrations (mercury, lead, aluminum, manganese and arsenic) far exceeded reference levels. No relationship was found between metal levels and auditory test results for the group as a whole. Statistically significant relationships were found between DPOAE response amplitudes and metal concentrations in a subgroup with less than 40 h per week of significant noise exposure; however, conclusions regarding these relationships should be tempered by the large number of analyses performed. Several young individuals with high metal levels reported neurological symptoms and had poor hearing. The data suggest that metal levels in artisanal mining communities present a significant public health problem and may affect hearing.

Serial analysis of the gut and respiratory microbiome in cystic fibrosis in infancy: interaction between intestinal and respiratory tracts and impact of nutritional exposures.

UNLABELLED: Pulmonary damage caused by chronic colonization of the cystic fibrosis (CF) lung by microbial communities is the proximal cause of respiratory failure. While there has been an effort to document the microbiome of the CF lung in pediatric and adult patients, little is known regarding the developing microflora in infants. We examined the respiratory and intestinal microbiota development in infants with CF from birth to 21 months. Distinct genera dominated in the gut compared to those in the respiratory tract, yet some bacteria overlapped, demonstrating a core microbiota dominated by Veillonella and Streptococcus. Bacterial diversity increased significantly over time, with evidence of more rapidly acquired diversity in the respiratory tract. There was a high degree of concordance between the bacteria that were increasing or decreasing over time in both compartments; in particular, a significant proportion (14/16 genera) increasing in the gut were also increasing in the respiratory tract. For 7 genera, gut colonization presages their appearance in the respiratory tract. Clustering analysis of respiratory samples indicated profiles of bacteria associated with breast-feeding, and for gut samples, introduction of solid foods even after adjustment for the time at which the sample was collected. Furthermore, changes in diet also result in altered respiratory microflora, suggesting a link between nutrition and development of microbial communities in the respiratory tract. Our findings suggest that nutritional factors and gut colonization patterns are determinants of the microbial development of respiratory tract microbiota in infants with CF and present opportunities for early intervention in CF with altered dietary or probiotic strategies. IMPORTANCE: While efforts have been focused on assessing the microbiome of pediatric and adult cystic fibrosis (CF) patients to understand how chronic colonization by these microbes contributes to pulmonary damage, little is known regarding the earliest development of respiratory and gut microflora in infants with CF. Our findings suggest that colonization of the respiratory tract by microbes is presaged by colonization of the gut and demonstrated a role of nutrition in development of the respiratory microflora. Thus, targeted dietary or probiotic strategies may be an effective means to change the course of the colonization of the CF lung and thereby improve patient outcomes.

Dietary intake of meat, fruits, vegetables, and selective micronutrients and risk of bladder cancer in the New England region of the United States.

BACKGROUND: Despite many studies on diet and bladder cancer, there are areas that remain unexplored including meat mutagens, specific vegetable groups, and vitamins from diet. METHODS: We conducted a population-based case-control study of bladder cancer in Maine, New Hampshire, and Vermont. A total of 1171 cases were ascertained through hospital pathology records and cancer registries from 2001 to 2004. Overall, 1418 controls were identified from the Department of Motor Vehicles (<65 years) and Center for Medicaid and Medicare Services (65-79 years) and were frequency-matched to cases by state, sex, and age (within 5 years). Diet was assessed with a self-administered Diet History Questionnaire. Unconditional logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (CI). RESULTS: Processed meat intake was positively associated with bladder cancer (highest vs lowest quartile OR: 1.28; 95% CI: 1.00-1.65; P(trend)=0.035), with a stronger association for processed red meat (OR: 1.41; 95% CI: 1.08-1.84; P(trend)=0.024). There were no associations between intake of fruits or vegetables and bladder cancer. We did, however, observe an inverse association with vitamin B12 intake (OR: 0.77; 95% CI: 0.61-0.99; P=0.019). CONCLUSION: Vitamin B12 from diet may be protective against bladder cancer, whereas consuming processed meat may increase risk.

Entropy-based information gain approaches to detect and to characterize gene-gene and gene-environment interactions/correlations of complex diseases.

For complex diseases, the relationship between genotypes, environment factors, and phenotype is usually complex and nonlinear. Our understanding of the genetic architecture of diseases has considerably increased over the last years. However, both conceptually and methodologically, detecting gene-gene and gene-environment interactions remains a challenge, despite the existence of a number of efficient methods. One method that offers great promises but has not yet been widely applied to genomic data is the entropy-based approach of information theory. In this article, we first develop entropy-based test statistics to identify two-way and higher order gene-gene and gene-environment interactions. We then apply these methods to a bladder cancer data set and thereby test their power and identify strengths and weaknesses. For two-way interactions, we propose an information gain (IG) approach based on mutual information. For three-ways and higher order interactions, an interaction IG approach is used. In both cases, we develop one-dimensional test statistics to analyze sparse data. Compared to the naive chi-square test, the test statistics we develop have similar or higher power and is robust. Applying it to the bladder cancer data set allowed to investigate the complex interactions between DNA repair gene single nucleotide polymorphisms, smoking status, and bladder cancer susceptibility. Although not yet widely applied, entropy-based approaches appear as a useful tool for detecting gene-gene and gene-environment interactions. The test statistics we develop add to a growing body methodologies that will gradually shed light on the complex architecture of common diseases.

Parity, early menopause and the incidence of bladder cancer in women: a case-control study and meta-analysis.

INTRODUCTION: Incidence rates of bladder cancer are notably higher in men than in women. While there is evidence that reproductive and hormonal risk factors may influence risk of bladder cancer, data are inconclusive. MATERIALS AND METHODS: We examined reproductive, menstrual and hormonal use history in our population-based case-control study of bladder cancer in New Hampshire (NH), USA (n=207 women cases and n=463 women controls). Additionally, we performed a meta-analysis of the published literature. We used unconditional logistic regression analysis to compute adjusted odds ratios associated with each risk factor in the NH study. We combined these estimates with those from the published literature using inverse variance effects models. RESULTS: In the NH study, a slightly decreased odds ratio was found among women who had ever had a birth compared to nulliparous women and an elevated odds ratio among women who underwent surgical menopause (bilateral oophorectomy), especially at an early age. No overall associations were found with oral contraceptive use or hormone replacement therapy. These findings were generally in agreement with the meta-analytic results for which the combined relative risk (RR) estimate was reduced among ever parous women (combined RR estimate for ever parous versus nulliparous=0.66, 95% confidence intervals [95% CI] 0.55-0.79) and elevated among those undergoing an early menopause (combined RR estimate for early versus late menopause=1.59, 95% CI 1.31-1.92). No consistent risk was observed for the other factors. DISCUSSION: Some reproductive and menstrual factors appear to be related to the incidence of bladder cancer among women; but whether effects are due to female hormones is uncertain.

GSTM1 null and NAT2 slow acetylation genotypes, smoking intensity and bladder cancer risk: results from the New England bladder cancer study and NAT2 meta-analysis.

Associations between bladder cancer risk and NAT2 and GSTM1 polymorphisms have emerged as some of the most consistent findings in the genetic epidemiology of common metabolic polymorphisms and cancer, but their interaction with tobacco use, intensity and duration remain unclear. In a New England population-based case-control study of urothelial carcinoma, we collected mouthwash samples from 1088 of 1171 cases (92.9%) and 1282 of 1418 controls (91.2%) for genotype analysis of GSTM1, GSTT1 and NAT2 polymorphisms. Odds ratios and 95% confidence intervals of bladder cancer among New England Bladder Cancer Study subjects with one or two inactive GSTM1 alleles (i.e. the 'null' genotype) were 1.26 (0.85-1.88) and 1.54 (1.05-2.25), respectively (P-trend = 0.008), compared with those with two active copies. GSTT1 inactive alleles were not associated with risk. NAT2 slow acetylation status was not associated with risk among never (1.04; 0.71-1.51), former (0.95; 0.75-1.20) or current smokers (1.33; 0.91-1.95); however, a relationship emerged when smoking intensity was evaluated. Among slow acetylators who ever smoked at least 40 cigarettes/day, risk was elevated among ever (1.82; 1.14-2.91, P-interaction = 0.07) and current heavy smokers (3.16; 1.22-8.19, P-interaction = 0.03) compared with rapid acetylators in each category; but was not observed at lower intensities. In contrast, the effect of GSTM1-null genotype was not greater among smokers, regardless of intensity. Meta-analysis of the NAT2 associations with bladder cancer showed a highly significant relationship. Findings from this large USA population-based study provided evidence that the NAT2 slow acetylation genotype interacts with tobacco smoking as a function of exposure intensity.

DNA methylation profiles delineate etiologic heterogeneity and clinically important subgroups of bladder cancer.

DNA methylation profiles can be used to define molecular cancer subtypes that may better inform disease etiology and clinical decision-making. This investigation aimed to create DNA methylation profiles of bladder cancer based on CpG methylation from almost 800 cancer-related genes and to then examine the relationship of those profiles with exposures related to risk and clinical characteristics. DNA, derived from formalin-fixed paraffin-embedded tumor samples obtained from incident cases involved in a population-based case-control study of bladder cancer in New Hampshire, was used for methylation profiling on the Illumina GoldenGate Methylation Bead Array. Unsupervised clustering of those loci with the greatest change in methylation between tumor and non-diseased tissue was performed to defined molecular subgroups of disease, and univariate tests of association followed by multinomial logistic regression was used to examine the association between these classes, bladder cancer risk factors and clinical phenotypes. Membership in the two most methylated classes was significantly associated with invasive disease (P < 0.001 for both class 3 and 4). Male gender (P = 0.04) and age >70 years (P = 0.05) was associated with membership in one of the most methylated classes. Finally, average water arsenic levels in the highest percentile predicted membership in an intermediately methylated class of tumors (P = 0.02 for both classes). Exposures and demographic associated with increased risk of bladder cancer specifically associate with particular subgroups of tumors defined by DNA methylation profiling and these subgroups may define more aggressive disease.

Glucocorticoid therapy and risk of bladder cancer.

BACKGROUND: Use of immunosuppressive drugs post organ transplantation, and prolonged use of glucorticoids for other conditions have been associated with subsequent risk of certain malignancies, that is, skin cancers and lymphoma. There is evidence that the incidence of bladder cancer is also elevated among organ transplant recipients, however, it is unknown whether other groups of patients, that is, those taking oral glucocorticoids, likewise are at an increased risk. METHODS: In a population-based case-control study in New Hampshire, USA, we compared the use of glucocorticoids in 786 bladder cancer cases and in 1083 controls. We used unconditional logistic regression analysis to compute adjusted odds ratios (ORs) associated with oral glucocorticoid use. RESULTS: In our analysis, the risk of bladder cancer was related to a history of prolonged oral glucocorticoid use (OR=1.85, 95% CI=1.24-2.76, adjusted for age, gender and smoking). Associations with oral glucocorticoid use were stronger for invasive tumours (OR=2.12, 95% CI=1.17-3.85) and tumours with high (3+) p53 staining intensity (OR=2.35, 95% CI=1.26-4.36). CONCLUSION: Our results raise the possibility of an increased risk of bladder cancer from systemic use of glucocorticoids, and a potential role of immune surveillance in bladder cancer aetiology.

Use of oral glucocorticoids and risk of skin cancer and non-Hodgkin's lymphoma: a population-based case-control study.

In North Jutland County, Denmark, we investigated whether use of oral glucocorticoids was associated with an increased risk of developing basal cell carcinoma (BCC), squamous cell carcinoma (SCC), malignant melanoma (MM), and non-Hodgkin's lymphoma (NHL). From the Danish Cancer Registry we identified 5422 BCC, 935 SCC, 983 MM, and 481 NHL cases during 1989-2003. Using risk-set sampling we selected four age- and gender-matched population controls for each case from the Civil Registration System. Prescriptions for oral glucocorticoids before diagnosis were obtained from the Prescription Database of North Jutland County on the basis of National Health Service data. We used conditional logistic regression to estimate incidence rate ratios (IRRs), adjusting for chronic medical diseases (information about these were obtained from the National Patient Registry) and use of other immunosuppressants. We found slightly elevated risk estimates for BCC (IRR, 1.15 (95% CI: 1.07-1.25)), SCC (IRR, 1.14 (95% CI: 0.94-1.39)), MM (IRR, 1.15 (95% CI: 0.94-1.41), and NHL (IRR, 1.11 (95% CI: 0.85-1.46)) among users of oral glucocorticoids. Our study supports an overall association between glucocorticoid use and risk of BCC that cannot be explained by the presence of chronic diseases or concomitant use of other immunosuppressants.

Use of photosensitising diuretics and risk of skin cancer: a population-based case-control study.

Diuretics have photosensitising properties. However, little is known about how these diuretics affect the risk of skin cancers. In North Jutland County, Denmark, we investigated whether the use of photosensitising diuretics was associated with an increased risk for developing basal cell carcinoma (BCC), squamous cell carcinoma (SCC) and malignant melanoma (MM). From the cancer registry, we identified primary cases of BCC, SCC and MM during the period of 1989-2003. We selected four population controls for each case from the Danish Civil Registration System, matched on age and gender. Prescriptions for photosensitising diuretics before cancer diagnosis were ascertained in the county's Prescription Database. We used conditional logistic regression to compute incidence rate ratio (IRR), controlling for the chronic medical conditions and for the previous use of oral glucocorticoids. We found an increased risk of SCC (IRR of 1.79 (95% confidence interval (CI): 1.45-2.21)) and MM (IRR of 1.43 (95% CI: 1.09-1.88)) among users of combined amiloride and hydrochlorothiazide therapy. An increased risk of MM (IRR of 3.30 (95% CI: 1.34-8.10)) was found among users of indapamide. We found little associations with risk of BCC. Our findings provide evidence that the use of some photosensitising diuretics is associated with an increased risk for SCC and MM.

Mortality in Danish patients with nonmelanoma skin cancer, 1978-2001.

BACKGROUND: Nonmelanoma skin cancer (NMSC) is a growing public health problem among Caucasians, thus mortality data that may provide insight into the clinical course and foster our understanding of NMSC are important. OBJECTIVES: We examined total and cause-specific mortality among patients with NMSC registered in the Danish Cancer Registry from 1978 to 2001. METHODS: A total of 82 837 patients with basal cell carcinoma (BCC) and 13 453 patients with squamous cell carcinoma (SCC) were followed through the National Death Registry for specific causes of death. Standardized mortality ratios (SMRs) were computed based on mortality rates in the general population. RESULTS: Among patients with BCC, we found a slightly reduced total mortality [SMR 0.97, 95% confidence interval (CI) 0.96-0.98] with decreased SMRs seen for chronic obstructive pulmonary disease (COPD), cardiovascular disease (CVD) and diabetes mellitus. The SMR for suicide was increased. Among patients with SCC, we found an increased total mortality (SMR 1.30, 95% CI 1.26-1.33) due primarily to excess deaths from cancers, COPD, CVD and infectious diseases. CONCLUSIONS: We found markedly different mortality patterns among patients with BCC and those with SCC, suggesting important differences in the clinical course of these patients.

A population-based study of immunohistochemical detection of p53 alteration in bladder cancer.

The molecular pathology of bladder cancer has been the subject of considerable interest and mutation of the p53 gene, which has been associated with more invasive bladder cancer, has been widely studied. Further, there is evidence that p53 inactivation (either mutation or protein dysregulation), independent of stage, may be predictive of bladder cancer progression. In an effort to avoid possible biases associated with selection of more advanced cases, we examined p53 inactivation in a population-based study of bladder cancer in New Hampshire, using both mutation and immunohistochemical methods. We found the overall prevalence of mutation to be approximately 10%, while immunohistochemical analysis suggests that approximately 66% of the tumours have dysregulated p53 at the protein level. There was a significant association of mutation with persistent p53 staining, but there remained a marked number of tumours discordant for mutation and aberrant p53 immunohistochemistry. Based upon immunohistochemical staining alone, intensity rather than extent of p53 staining was more strongly related to tumour invasiveness. Additionally, all tumours with a mutation in exon 8 stained intensely. Taken together, this suggests that intense staining represents a distinct phenotype of dysfunctional protein. Our data indicate that population-based approaches to somatic alteration of p53 in bladder cancer are crucial to understanding the relationship of p53 changes to aetiology and the outcome of this disease, and further suggest that the pattern of immunohistochemical staining may represent distinct, discernible phenotypes. British Journal of Cancer (2004) 90, 1572-1576. doi:10.1038/sj.bjc.6601748 www.bjcancer.com Published online 6 April 2004

A pooled analysis of 10 case-control studies of melanoma and oral contraceptive use.

Data regarding the effects of oral contraceptive use on women's risk of melanoma have been difficult to resolve. We undertook a pooled analysis of all case-control studies of melanoma in women completed as of July 1994 for which electronic data were available on oral contraceptive use along with other melanoma risk factors such as hair colour, sun sensitivity, family history of melanoma and sun exposure. Using the original data from each investigation (a total of 2391 cases and 3199 controls), we combined the study-specific odds ratios and standard errors to obtain a pooled estimate that incorporates inter-study heterogeneity. Overall, we observed no excess risk associated with oral contraceptive use for 1 year or longer compared to never use or use for less than 1 year (pooled odds ratio (pOR)=0.86; 95% CI=0.74-1.01), and there was no evidence of heterogeneity between studies. We found no relation between melanoma incidence and duration of oral contraceptive use, age began, year of use, years since first use or last use, or specifically current oral contraceptive use. In aggregate, our findings do not suggest a major role of oral contraceptive use on women's risk of melanoma.