Alcohol, tobacco and breast cancer--collaborative reanalysis of individual data from 53 epidemiological studies, including 58,515 women with breast cancer and 95,067 women without the disease

Alcohol and tobacco consumption are closely correlated and published results on their association with breast cancer have not always allowed adequately for confounding between these exposures. Over 80% of the relevant information worldwide on alcohol and tobacco consumption and breast cancer were collated, checked and analysed centrally. Analyses included 58,515 women with invasive breast cancer and 95,067 controls from 53 studies. Relative risks of breast cancer were estimated, after stratifying by study, age, parity and, where appropriate, women's age when their first child was born and consumption of alcohol and tobacco. The average consumption of alcohol reported by controls from developed countries was 6.0 g per day, i.e. about half a unit/drink of alcohol per day, and was greater in ever-smokers than never-smokers, (8.4 g per day and 5.0 g per day, respectively). Compared with women who reported drinking no alcohol, the relative risk of breast cancer was 1.32 (1.19-1.45, P<0.00001) for an intake of 35-44 g per day alcohol, and 1.46 (1.33-1.61, P<0.00001) for >/=45 g per day alcohol. The relative risk of breast cancer increased by 7.1% (95% CI 5.5-8.7%; P<0.00001) for each additional 10 g per day intake of alcohol, i.e. for each extra unit or drink of alcohol consumed on a daily basis. This increase was the same in ever-smokers and never-smokers (7.1% per 10 g per day, P<0.00001, in each group). By contrast, the relationship between smoking and breast cancer was substantially confounded by the effect of alcohol. When analyses were restricted to 22 255 women with breast cancer and 40 832 controls who reported drinking no alcohol, smoking was not associated with breast cancer (compared to never-smokers, relative risk for ever-smokers=1.03, 95% CI 0.98-1.07, and for current smokers=0.99, 0.92-1.05). The results for alcohol and for tobacco did not vary substantially across studies, study designs, or according to 15 personal characteristics of the women; nor were the findings materially confounded by any of these factors. If the observed relationship for alcohol is causal, these results suggest that about 4% of the breast cancers in developed countries are attributable to alcohol. In developing countries, where alcohol consumption among controls averaged only 0.4 g per day, alcohol would have a negligible effect on the incidence of breast cancer. In conclusion, smoking has little or no independent effect on the risk of developing breast cancer; the effect of alcohol on breast cancer needs to be interpreted in the context of its beneficial effects, in moderation, on cardiovascular disease and its harmful effects on cirrhosis and cancers of the mouth, larynx, oesophagus and liver.

Administration of Lactobacillus helveticus NS8 improves behavioral, cognitive, and biochemical aberrations caused by chronic restraint stress

Increasing numbers of studies have suggested that the gut microbiota is involved in the pathophysiology of stress-related disorders. Chronic stress can cause behavioral, cognitive, biochemical, and gut microbiota aberrations. Gut bacteria can communicate with the host through the microbiota-gut-brain axis (which mainly includes the immune, neuroendocrine, and neural pathways) to influence brain and behavior. It is hypothesized that administration of probiotics can improve chronic-stress-induced depression. In order to examine this hypothesis, the chronic restraint stress depression model was established in this study. Adult specific pathogen free (SPF) Sprague-Dawley rats were subjected to 21 days of restraint stress followed by behavioral testing (including the sucrose preference test (SPT), elevated-plus maze test, open-field test (OFT), object recognition test (ORT), and object placement test (OPT)) and biochemical analysis. Supplemental Lactobacillus helveticus NS8 was provided every day during stress until the end of experiment, and selective serotonin reuptake inhibitor (SSRI) citalopram (CIT) served as a positive control. Results showed that L. helveticus NS8 improved chronic restraint stress-induced behavioral (anxiety and depression) and cognitive dysfunction, showing an effect similar to and better than that of CIT. L. helveticus NS8 also resulted in lower plasma corticosterone (CORT) and adrenocorticotropic hormone (ACTH) levels, higher plasma interleukin-10 (IL-10) levels, restored hippocampal serotonin (5-HT) and norepinephrine (NE) levels, and more hippocampal brain-derived neurotrophic factor (BDNF) mRNA expression than in chronic stress rats. Taken together, these results indicate an anti-depressant effect of L. helveticus NS8 in rats subjected to chronic restraint stress depression and that this effect could be due to the microbiota-gut-brain axis. They also suggest the therapeutic potential of L. helveticus NS8 in stress-related and possibly other kinds of depression.

Validity and reproducibility of the food frequency questionnaire used in the Shanghai Women's Health Study

To evaluate the validity and reliability of the food frequency questionnaire (FFQ) used in the Shanghai Women's Health Study (SWHS), 200 SWHS participants were recruited for a dietary calibration study. Study participants completed an FFQ at baseline and 24-h dietary recalls (24-HDR) twice per month consecutively for 12 months. At the end of the study, a second FFQ was administered. Of the 200 study participants, 196 completed 24 or more days of 24-h dietary recalls, 191 completed two FFQs from whom the results of this report were based. The FFQ included the foods that accounted for 86% of the foods recorded in the 24-HDR surveys. Validity of the FFQ was evaluated by comparing intake levels of major nutrients and foods obtained from the second FFQ with those derived from the multiple 24-HDR. The median intake for major nutrients, rice, poultry and meat derived from the second FFQ and the 24-HDR was similar, with the differences ranging from 1.3 to 12.1%. The FFQ tended to overestimate the intake level of total vegetables and total fruits, and the differences were explained mainly by over-reporting seasonal vegetables and fruits consumption in the FFQ. Nutrient and food intake assessed by the FFQ and the multiple 24-HDR correlated very well, with the correlation coefficients being 0.59-0.66 for macronutrients, 0.41-0.59 for micronutrients, and 0.41-0.66 for major food groups. The reliability of the FFQ was assessed by comparing the correlation and median intake of nutrients and food groups obtained from the two FFQs that were administered approximately 2 y apart. The median intake levels for selected nutrients and food groups derived from the two FFQs were similar with differences below 10%. At the individual level, the intake levels of these dietary variables obtained from two FFQs also correlated well. When nutrient and food group intakes were categorized into quartiles, FFQ and 24-HDR produced exact agreement rates between 33 and 50%. Misclassification to adjacent quartile was common, ranging from 34-48%, while misclassification to an extreme quartile was rare (1-6%). These data indicate that the SWHS FFQ can reliably and accurately measure usual intake of major nutrients and food groups among women in Shanghai.

The tuberous sclerosis 2 gene product, tuberin, functions as a Rab5 GTPase activating protein (GAP) in modulating endocytosis

The tuberous sclerosis complex 2 (TSC2) is a tumor suppressor gene that plays a causative role in the autosomal dominant syndrome of tuberous sclerosis. The latter is characterized by the development of hamartomas and occasional malignancies. Expression of the wild-type gene in TSC2 mutant tumor cells inhibits proliferation and tumorigenicity. This "suppressor" activity is encoded by functional domain(s) in the C terminus that contains homology to Rap1GAP. Using a yeast two-hybrid assay to identify proteins that interact with the C-terminal domain of tuberin, the product of TSC2, a cytosolic factor, rabaptin-5, was found to associate with a distinct domain lying adjacent to the TSC2 GAP homology region. Rabaptin-5 also binds the active form of GTPase Rab5. Immune complexes of native tuberin, as well as recombinant protein, possessed activity to stimulate GTP hydrolysis of Rab5. Tuberin GAP activity was specific for Rab5 and showed no cross-reactivity with Rab3a or Rab6. Cells lacking tuberin possessed minimal Rab5GAP activity and were associated with an increased uptake of horseradish peroxidase. Re-expression of tuberin in TSC2 mutant cells reduced the rate of fluid-phase endocytosis. These findings suggest that tuberin functions as a Rab5GAP in vivo to negatively regulate Rab5-GTP activity in endocytosis.

Paternal cigarette smoking and the risk of childhood cancer among offspring of nonsmoking mothers

BACKGROUND

Cigarette smoking has been shown to increase oxidative DNA damage in human sperm cells. Assessment of the role of cigarette smoking in the etiology of childhood cancer has focused primarily on the effect of maternal smoking. Similar studies in relation to paternal smoking, however, have been inconclusive. Few studies have evaluated the effect of paternal smoking in the preconception period, and most of these could not disentangle the effects of paternal from maternal smoking.

PURPOSE

We investigated the relationship of paternal smoking, particularly in the preconception period, with childhood cancer among offspring of the nonsmoking mothers.

METHODS

We conducted a population-based, case-control study in Shanghai, People's Republic of China, where the prevalence of smoking is high among men but extremely low among women. The study included 642 childhood cancer case patients (<15 years of age) and their individually matched control subjects. Information concerning parental smoking, alcohol drinking, and other exposures of the index child was obtained by direct interview of both parents of the study subjects. Odds ratios (ORs), derived from conditional logistic regression models, were used to measure the association between paternal smoking and risk of childhood cancers.

RESULTS AND CONCLUSIONS

Paternal preconception smoking was related to a significantly elevated risk of childhood cancers, particularly acute leukemia and lymphoma. The risks rose with increasing pack-years of paternal preconception smoking for acute lymphocytic leukemia (ALL) (P for trend = .01), lymphoma (P for trend = .07), and total cancer (P for trend = .006). Compared with children whose fathers had never smoked cigarettes, children whose fathers smoked more than five pack-years prior to their conception had adjusted ORs of 3.8 (95% confidence interval [CI] = 1.3-12.3) for ALL, 4.5 (95% CI = 1.2-16.8) for lymphoma, 2.7 (95% CI = 0.8-9.9) for brain tumors, and 1.7 (95% CI = 1.2-2.5) for all cancers combined. Statistically significant increased risks of cancer were restricted to children under the age of 5 years at diagnosis or those whose fathers had smoked during all of the 5 years prior to conception.

IMPLICATIONS

Further studies are needed to confirm the association of paternal smoking with increased risk of cancer in offspring, to clarify the pattern of risks in relation to the timing of cigarette smoking, and to elucidate the biologic mechanism involved in predisposing the offspring to cancer. For example, it may be that paternal smoking induces prezygotic genetic damage that, in turn, acts as the predisposing factor.

Predisposition to renal carcinoma in the Eker rat is determined by germ-line mutation of the tuberous sclerosis 2 (TSC2) gene

Genetic predisposition to neoplasia often involves tumor suppressor genes. One such model of hereditary renal carcinoma was described in the rat by Eker. These tumors share morphologic similarities with human renal cancer. Linkage analysis localized the inherited mutation to rat chromosome band 10q12. This region is syntenic with human chromosome band 16p13.3, the site of the tuberous sclerosis 2 (TSC2) gene. A specific rearrangement of the rat homologue of TSC2 was found to cosegregate with carriers of the predisposing mutation. Tumors with or without loss of heterozygosity expressed only the mutant allele, consistent with the two-hit hypothesis. This mutation gave rise to an aberrant transcript that deletes the 3' end normally containing a region of homology with the catalytic domain of rap1GAP.

Nonlinear modelling of cancer: bridging the gap between cells and tumours

Despite major scientific, medical and technological advances over the last few decades, a cure for cancer remains elusive. The disease initiation is complex, and including initiation and avascular growth, onset of hypoxia and acidosis due to accumulation of cells beyond normal physiological conditions, inducement of angiogenesis from the surrounding vasculature, tumour vascularization and further growth, and invasion of surrounding tissue and metastasis. Although the focus historically has been to study these events through experimental and clinical observations, mathematical modelling and simulation that enable analysis at multiple time and spatial scales have also complemented these efforts. Here, we provide an overview of this multiscale modelling focusing on the growth phase of tumours and bypassing the initial stage of tumourigenesis. While we briefly review discrete modelling, our focus is on the continuum approach. We limit the scope further by considering models of tumour progression that do not distinguish tumour cells by their age. We also do not consider immune system interactions nor do we describe models of therapy. We do discuss hybrid-modelling frameworks, where the tumour tissue is modelled using both discrete (cell-scale) and continuum (tumour-scale) elements, thus connecting the micrometre to the centimetre tumour scale. We review recent examples that incorporate experimental data into model parameters. We show that recent mathematical modelling predicts that transport limitations of cell nutrients, oxygen and growth factors may result in cell death that leads to morphological instability, providing a mechanism for invasion via tumour fingering and fragmentation. These conditions induce selection pressure for cell survivability, and may lead to additional genetic mutations. Mathematical modelling further shows that parameters that control the tumour mass shape also control its ability to invade. Thus, tumour morphology may serve as a predictor of invasiveness and treatment prognosis.

Association of menstrual and reproductive factors with breast cancer risk: results from the Shanghai Breast Cancer Study

The incidence of breast cancer among women in Shanghai, a traditionally low-risk population, has increased substantially over the past 20 years. To evaluate the association of menstrual and reproductive factors with breast cancer risk and the influence of these factors on the temporal trend of breast cancer incidence, we analyzed data from the Shanghai Breast Cancer Study, a population-based case-control study of breast cancer recently completed among Chinese women in urban Shanghai. In-person interviews were completed for 1,459 women newly diagnosed with breast cancer between ages 25 and 64 and for 1,556 controls frequency-matched to cases by age. Unconditional logistic regression was employed to estimate adjusted odds ratios (ORs) and 95% confidence intervals (CIs) related to menstrual and reproductive factors. Earlier menarcheal age, nulliparity, and later age at first live birth were associated with increased risk of breast cancer among both pre- and post-menopausal women, while never having breast-fed and later age at menopause were associated with elevated risk only among post-menopausal women. Among controls, 32% of younger women (</=40 years) and 24% of older women (>40 years) reported starting menarche at age of 13 or younger, and this factor contributed to 44% of cases diagnosed among younger women and 26% to 28% of cases in older women. Older age at first live birth or at menopause explained a considerable portion of cases diagnosed in older, but not younger, women. Our study suggests that the changes in menstrual and reproductive patterns among women in Shanghai have contributed to the recent increase in breast cancer incidence, particularly among younger women.

Characterization of the interactions of alpha-catenin with alpha-actinin and beta-catenin/plakoglobin

Cadherins are calcium-dependent, cell surface glycoproteins involved in cell-cell adhesion. To function in cell-cell adhesion, the transmembrane cadherin molecule must be associated with the cytoskeleton via cytoplasmic proteins known as catenins. Three catenins, alpha-catenin, beta-catenin and gamma-catenin (also known as plakoglobin), have been identified. beta-catenin or plakoglobin is associated directly with the cadherin; alpha-catenin binds to beta-catenin/plakoglobin and serves to link the cadherin/catenin complex to the actin cytoskeleton. The domains on the cadherin and betacatenin/plakoglobin that are responsible for protein-protein interactions have been mapped. However, little is known about the molecular interactions between alpha-catenin and beta-catenin/plakoglobin or about the interactions between alpha-catenin and the cytoskeleton. In this study we have used the yeast two-hybrid system to map the domains on alpha-catenin that allow it to associate with beta-catenin/plakoglobin and with alpha-actinin. We also identify a region on alpha-actinin that is responsible for its interaction with alpha-catenin. The yeast two-hybrid data were confirmed with biochemical studies.

Multimodal analgesia for postoperative pain control

Pain is one of the main postoperative adverse outcomes. Single analgesics, either opioid or nonsteroidal antiinflammatory drugs (NSAIDs), are not able to provide effective pain relief without side effects such as nausea, vomiting, sedation, or bleeding. A majority of double or single-blind studies investigating the use of NSAIDs and opioid analgesics with or without local anesthetic infiltration showed that patients experience lower pain scores, need fewer analgesics, and have a prolonged time to requiring analgesics after surgery. This review focuses on multimodal analgesia, which is currently recommended for effective postoperative pain control.

Minimizing perioperative adverse events in the elderly

Elderly patients still have the highest postoperative mortality and morbidity rate in the adult surgical population. Preoperative clinical assessment to detect patients at high risk of postoperative events, and specific intraoperative and postoperative anaesthesia management are important to minimize postoperative adverse events in the elderly.

Lactobacillus fermentum NS9 restores the antibiotic induced physiological and psychological abnormalities in rats

Gut microbiota play a vital role in maintaining the health of the host. Many factors affect gut microbiota; application of broad range antibiotics disturb microbiota, while probiotic application protects the microbiota. To investigate how probiotics alter the physiological and psychological changes induced by antibiotics, we tested the performance of ampicillin-treated rats in the presence or absence of Lactobacillus fermentum strain NS9, in elevated plus maze and Morris water maze. The results showed that NS9 normalised the composition of gut microbiota and alleviated the ampicillin-induced inflammation in the colon. The levels of the mineralocorticoid and N-methyl-D-aspartate receptors were also elevated in the hippocampus of the ampillicin+NS9 treated group. NS9 administration also reduced the anxiety-like behaviour and alleviated the ampicillin-induced impairment in memory retention. These findings suggest that NS9 is beneficial to the host, because it restores the physiological and psychological abnormalities induced by ampicillin. Our results highlight how gut contents regulate the brain, and shed light on the clinical applications of probiotics to treat the side effect of antibiotics and mental disorders.

Migration of cardiac neural crest cells in Splotch embryos

Pax3 encodes a transcription factor expressed during mid-gestation in the region of the dorsal neural tube that gives rise to migrating neural crest populations. In the absence of Pax3, both humans and mice develop with neural crest defects. Homozygous Splotch embryos that lack Pax3 die by embryonic day 13.5 with cardiac defects that resemble those induced by neural crest ablation in chick models. This has led to the hypothesis that Pax3 is required for cardiac neural crest migration. However, cardiac derivatives of Pax3-expressing precursor cells have not been previously defined, and Pax3-expressing cells within the heart have not been well demonstrated. Hence, the precise role of Pax3 during cardiac development remains unclear. Here, we use a Cre-lox method to fate map Pax3-expressing neural crest precursors to the cardiac outflow tract. We show that although Pax3 itself is extinguished prior to neural crest populating the heart, derivatives of these precursors contribute to the aorticopulmonary septum. We further show that neural crest cells are found in the outflow tract of Splotch embryos, albeit in reduced numbers. This indicates that contrary to prior reports, Pax3 is not required for cardiac neural crest migration. Using a neural tube explant culture assay, we demonstrate that neural crest cells from Splotch embryos show normal rates of proliferation but altered migratory characteristics. These studies suggest that Pax3 is required for fine tuning the migratory behavior of the cardiac neural crest cells while it is not essential for neural crest migration.

Population-based case-control study of soyfood intake and breast cancer risk in Shanghai

We evaluated the association of soyfood intake and breast cancer risk in a population-based case-control study among Chinese women in Shanghai. Included in the study were 1459 cases and 1556 age-matched controls, with respective response rates of 91.1% and 90.3%. Usual soyfood intake was assessed using a food frequency questionnaire (FFQ). Separate analyses were performed for all subjects and for the subset who reported no recent change in soyfood intake. The intake levels of soyfoods among women in Shanghai are high, with 96.6% women reporting soyfood consumption at least once a week. A statistically non-significant reduced risk (odds ratio (OR) = 0.78 95% CI = 0.52-1.16) of breast cancer was observed among those who reported eating soyfood at least once a week. Compared to those in the lowest decile intake group, women in the highest decile intake group had a 30% reduced risk of breast cancer (OR = 0.66, 95% CI = 0.46-0.95), but no monotonic dose-response relation was observed (P for trend, 0.28). Stratified analyses showed that the inverse association was restricted primarily among women who had a high body mass index (BMI), with an adjusted OR of 0.30 (95% CI = 0.10-0.94) observed for the highest intake group. The reduction in risk was stronger for breast cancer positive for both oestrogen receptor (ER) and progesterone receptor (PR) (OR = 0.44, 95% CI = 0.25-0.78) than those with other ER/PR status. More pronounced inverse associations were observed in analyses among those who reported no recent change in soyfood intake than those conducted in all subjects. A dose-response relation between soyfood intake and breast cancer risk was observed in this subset of women (P for trend, 0.02), with an OR of 0.46 (95%CI = 0.28-0.75) for those in the highest decile intake group. No clear monotonic dose-response relation was found between soyfood intake and breast cancer risk among regular soy eaters, but nevertheless the results suggest that regular soyfood consumption may reduce the risk of breast cancer, particularly for those positive for ER and PR; the effect may be modified by body mass index.

Usual dietary consumption of soy foods and its correlation with the excretion rate of isoflavonoids in overnight urine samples among Chinese women in Shanghai

Soy foods and certain soy constituents, particularly isoflavones, have been suggested to have potential cancer-inhibitory effects in laboratory and epidemiological studies. Chinese women in Shanghai consume high levels of soy foods and have low incidence rates of breast and other hormone-related cancers. To assess the usual dietary consumption of soy foods and evaluate the correlation of soy food consumption with the urinary excretion of isoflavonoids in overnight urine samples in this population, we analyzed data from 60 healthy women included in an ongoing population-based case-control study of breast cancer in Shanghai. Usual consumption of soy foods in the previous five-year period was assessed using a food-frequency questionnaire, and urinary excretion of daidzein, genistein, glycitein, equol, and O-desmethylangolensin was measured from overnight urine samples collected at the time of dietary assessment. Virtually all women (96.7%) in Shanghai consumed soy foods at least once a week. The median intake of soy food was 100.6 g/day, with 25th and 75th percentiles of 36.8 and 238.2 g, respectively. The median intake of isoflavones was 39.26 mg/day, and there was a nearly fourfold difference between the 25th and 75th percentiles of this measurement. With the increasing intake of soy foods, urinary excretion rates of total isoflavonoids and all individual major isoflavonoids were increased in a dose-response manner (trend test p < or = 0.05). At individual levels the urinary excretion rate of total isoflavonoids was correlated closely with dietary soy food intake, with a correlation coefficient of around 0.5 (p < 0.001). These results indicate that the urinary excretion rate of total isoflavonoids measured from overnight urine samples may reflect reasonably well the usual intake of soy foods in a population with a high level of soy food consumption.

Cancer incidence trends in urban shanghai, 1972-1994: an update

Incidence rates for a number of cancers in urban Shanghai, China, have been changing markedly. Herein we update the trends using population-based data from the Shanghai Cancer Registry for 1972-1994. During 1993-1994, cancers of the lung, stomach, and liver were the 3 leading forms among men, with age-adjusted (world standard) incidence rates of 50.9, 39.2, and 26.5 per 100,000 person-years, respectively, followed by cancers of the colon (12.4) and esophagus (10.0). Among women, cancers of the breast (27.5), stomach (19.1), and lung (17.7) were the most common tumors, followed by cancers of the colon (11.3) and liver (9.4). Over the 23-year period, the rate for all cancers combined, excluding non-melanoma skin cancer, decreased from 247.5 to 215.2 among men and from 173.6 to 154.0 among women. However, trends for individual forms of cancer varied considerably. Rates doubled for cancers of the colon and biliary tract in both sexes, and they increased substantially for cancers of the brain and nervous system, kidney, pancreas, prostate, corpus uteri, female breast, and ovary, and for non-Hodgkin's lymphoma. Rates for cancers of the lung and rectum changed little. Rates declined by at least one-half for cancers of the esophagus and cervix, with notable decreases also for cancers of the stomach and liver. Some of these trends may reflect variations in diagnostic or screening practices, although changes in lifestyle and other environmental exposures are likely to play important roles. Further epidemiologic research in China is needed to identify risk factors influencing the cancer incidence trends.

Population-based, case-control study of HER2 genetic polymorphism and breast cancer risk

BACKGROUND

Alterations of the HER2 (also known as erbB-2 or neu) proto-oncogene have been implicated in the carcinogenesis and prognosis of breast cancer. A polymorphism at codon 655 (GTC/valine to ATC /isoleucine [Val(655)Ile]) in the transmembrane domain-coding region of this gene has been identified and may be associated with the risk of breast cancer. We evaluated this hypothesis in a subgroup of women who participated in a large-scale, population-based, case-control study of breast cancer in Shanghai, China.

METHODS

Genomic DNA from 339 patients with breast cancer and 361 healthy control subjects was examined for the Val(655)Ile polymorphism with a polymerase chain reaction-restriction fragment-length polymorphism-based assay. All study subjects completed a structured questionnaire during an in-person interview. All P values are from two-sided tests.

RESULTS

We found that 25.1% of the case patients and 21.7% of the control subjects were heterozygous for the Val allele and 3.2% of the case patients and 0. 3% of the control subjects were homozygous for this allele (P =.005). Compared with women with the Ile/Ile genotype, women who had the Ile/Val or Val/Val genotype had an elevated risk of breast cancer (odds ratio [OR] = 1.4; 95% confidence interval [CI] = 1.0-2.0; P =. 05) after adjustment for age, educational level, study period, history of breast fibroadenoma, leisure physical activity, and age at first live birth. The risk was elevated even more among women who were homozygous for the Val allele (OR = 14.1; 95% CI = 1.8-113.4). The association was more pronounced among younger women (</=45 years) than among older women (>45 years). The adjusted OR associated with the Val allele was 1.7 (95% CI = 1.1-2.6) for younger women and 1.0 (95% CI = 0.5-1.9) for older women.

CONCLUSIONS

Results of this study suggest that polymorphisms of the HER2 gene may be important susceptibility biomarkers for breast cancer risk, particularly among younger women.

The influence of cigarette smoking, alcohol, and green tea consumption on the risk of carcinoma of the cardia and distal stomach in Shanghai, China

BACKGROUND

The divergent incidence patterns of gastric cardia and distal stomach cancer may suggest different etiologies. This study examined the role of cigarette smoking, alcohol drinking, and green tea consumption as risk factors for carcinoma by anatomic subsite of stomach.

METHODS

Newly-diagnosed stomach carcinoma patients (n = 1124) and frequency-matched population controls (n = 1451) were interviewed in person. Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using logistic regression models.

RESULTS

Excess risks associated with cigarette smoking and alcohol consumption were observed largely among men. The adjusted ORs for all stomach cancer combined were 1.35 (CI: 1.06-1.71) for current smokers, and 1.26 (CI: 0.86-1.84) for ex-smokers. For tumors of the distal stomach, statistically significant positive dose-response trends were found for the number of cigarettes smoked per day, the duration and pack-years of smoking, and inverse trends for years of stopped smoking. For tumors of the gastric cardia, however, a monotonic association was found only for the number of cigarettes smoked per day (P=0.06). Alcohol consumption was not related to the risk of cardia cancer, while a moderate excess risk of distal stomach cancer (OR: 1.55; CI: 1.07-2.26) was observed among heavy alcohol drinkers. Green tea drinking was inversely associated with risk of stomach cancer arising from either subsite, with ORs of 0.77 (CI: 0.52-1.13) among female heavy drinkers, and 0.76 (CI: 0.55-1.27) among male heavy drinkers.

CONCLUSIONS

Our findings provide further evidence that cigarette smoking and, possibly, alcohol consumption increase the risk of stomach carcinoma, notably of the distal segment. An inverse association with green tea drinking was also observed.

A pooled analysis of thyroid cancer studies. V. Anthropometric factors

OBJECTIVE

To assess the relation between anthropometric factors and thyroid cancer risk in a pooled analysis of individual data from 12 case-control studies conducted in the US, Japan, China and Europe.

METHODS

2056 female and 417 male cases, 3358 female and 965 male controls were considered. Odds ratios (OR) were derived from logistic regression, conditioning on age, A-bomb exposure (Japan) and study, and adjusting for radiotherapy.

RESULTS

Compared to the lowest tertile of height, the pooled OR was 1.2 for females for the highest one, and 1.5 for males, and trends in risk were significant. With reference to weight at diagnosis, the OR for females was 1.2 for the highest tertile, and the trend in risk was significant, whereas no association was observed in males. Body mass index (BMI) at diagnosis was directly related to thyroid cancer risk in females (OR = 1.2 for the highest tertile), but not in males. No consistent pattern of risk emerged with BMI during the late teens. Most of the associations were observed both for papillary and follicular cancers, and in all age groups. However, significant heterogeneity was observed across studies.

CONCLUSIONS

Height and weight at diagnosis are moderately related to thyroid cancer risk.

Sulfation pharmacogenetics: SULT1A1 and SULT1A2 allele frequencies in Caucasian, Chinese and African-American subjects

Sulfotransferase (SULT) enzymes catalyze the sulfate conjugation of drugs, other xenobiotics, neurotransmitters and hormones. The genes for SULT1A1 and SULT1A2 contain common genetic polymorphisms that are associated with individual variations in levels of enzyme activity as well as variations in biochemical and physical properties. We set out to compare the frequencies of common SULT1A1 and SULT1A2 alleles in Caucasian, Chinese and African-American subjects. Allele frequencies for SULT1A1*1, *2 and *3 in 242 Caucasian subjects were 0.656, 0.332 and 0.012, respectively. Frequencies of those same alleles were significantly different in 290 Chinese subjects: 0.914, 0.080 and 0.006, respectively, as were frequencies in 70 African-American subjects: 0.477, 0.294 and 0.229, respectively. Ethnic variation in allele frequencies was also observed for SULT1A2, with frequencies in Caucasian subjects for SULT1A2*1, *2 and *3 of 0.507, 0.389 and 0.104; frequencies in Chinese of 0.924 and 0.076 with no *3 alleles observed; and, finally, in African-Americans frequencies of 0.637, 0.249 and 0.114, respectively. We also found that SULT1A1*2 and SULT1A2*2, the most common variant alleles for these two genes, were in positive linkage disequilibrium in all three populations studied, with D' values of 0.776 in Caucasian (P < 0.001), 0.915 in Chinese (P < 0.001) and 0.864 in African-American subjects (P < 0.001). These observations represent a step towards determining the possible functional implications for individual variations in sulfate conjugation of common genetic polymorphisms for SULT1A1 and SULT1A2.

Pax3 functions in cell survival and in pax7 regulation

In developing vertebrate embryos, Pax3 is expressed in the neural tube and in the paraxial mesoderm that gives rise to skeletal muscles. Pax3 mutants develop muscular and neural tube defects; furthermore, Pax3 is essential for the proper activation of the myogenic determination factor gene, MyoD, during early muscle development and PAX3 chromosomal translocations result in muscle tumors, providing evidence that Pax3 has diverse functions in myogenesis. To investigate the specific functions of Pax3 in development, we have examined cell survival and gene expression in presomitic mesoderm, somites and neural tube of developing wild-type and Pax3 mutant (Splotch) mouse embryos. Disruption of Pax3 expression by antisense oligonucleotides significantly impairs MyoD activation by signals from neural tube/notochord and surface ectoderm in cultured presomitic mesoderm (PSM), and is accompanied by a marked increase in programmed cell death. In Pax3 mutant (Splotch) embryos, MyoD is activated normally in the hypaxial somite, but MyoD-expressing cells are disorganized and apoptosis is prevalent in newly formed somites, but not in the neural tube or mature somites. In neural tube and somite regions where cell survival is maintained, the closely related Pax7 gene is upregulated, and its expression becomes expanded into the dorsal neural tube and somites, where Pax3 would normally be expressed. These results establish that Pax3 has complementary functions in MyoD activation and inhibition of apoptosis in the somitic mesoderm and in repression of Pax7 during neural tube and somite development.

Impaired bone formation in transgenic mice resulting from altered integrin function in osteoblasts

To determine the role of integrins in mature osteoblasts in vivo, we expressed in transgenic mice a dominant-negative integrin subunit (beta1-DN) consisting of the beta1 subunit cytoplasmic and transmembrane domains, driven by the osteoblast-specific osteocalcin promoter. Immature osteoblasts isolated from transgenic animals differentiated normally in vitro until the osteocalcin promoter became active; thereafter they detached from the substratum, suggesting that beta1-DN was impairing adhesion in mature osteoblasts. Transgenic animals had reduced bone mass, with increased cortical porosity in long bones and thinner flat bones in the skull. At 35 days, the rate of bone formation was reduced in cortical bone, and the parietal bones were 45% thinner than in wild-type animals. Active osteoblasts were less polar and had larger areas of cytoplasm with intracellular stores of matrix molecules. Osteocyte lacunae appeared normal around the cell body but did not have normal canilicular structures. At 90 days, the parietal bone of transgenic males was of normal width, suggesting that the original defect in matrix deposition had been repaired or compensated for. In contrast, transgenic females still had decreased bone mass in the parietal bone at 90 days. The decreased bone mass in TG females was accompanied by increased staining for osteoclast activity, suggesting that there was a sex-specific defect in mature animals.

Incidence and risk factors for urethral and anal gonorrhoea and chlamydia in a cohort of HIV-negative homosexual men: the Health in Men Study

BACKGROUND

Early detection and treatment of bacterial sexually transmitted infections has been advocated as an HIV prevention strategy.

AIM

To inform screening guidelines, the incidence and risk factors for urethral and anal gonorrhoea and chlamydia were studied in a prospective cohort of community-based HIV negative homosexual men in Sydney, New South Wales, Australia.

METHODS

All participants were offered annual screening for gonorrhoea and chlamydia (study-visit diagnoses) on urine and anal swabs using nucleic acid amplification. Participants also reported diagnoses of gonorrhoea and chlamydia made elsewhere between interviews (interval diagnoses). All diagnoses were summed to create a combined incidence rate, and detailed data on specific sexual practices with casual and regular partners were collected.

RESULTS

Among 1427 men enrolled, the combined incidence rates were 3.49 and 2.96 per 100 person-years for urethral and anal gonorrhoea, respectively; and 7.43 and 4.98 per 100 person-years for urethral and anal chlamydia, respectively. Urethral infections were associated with unprotected anal intercourse (UAI) with HIV-positive partners (hazard ratio (HR) = 2.58, 95% CI 1.10 to 6.05 for urethral gonorrhoea) and with frequent insertive oral sex (p for trend 0.007 for urethral chlamydia). Anal infections were associated with receptive UAI (p for trend 0.001 for both anal gonorrhoea and chlamydia) and other receptive anal sexual practices. Stratified analyses showed the independence of the associations of insertive oral sex with urethral infections and of non-intercourse receptive anal practices with anal infections.

CONCLUSION

Incident gonorrhoea and chlamydia were common. Risk behaviours for both urethral and anal infections were not restricted to UAI. Screening that includes tests for anal and urethral infections should be considered for all sexually active homosexual men, not just for those who report UAI.

A pooled analysis of case-control studies of thyroid cancer. IV. Benign thyroid diseases

OBJECTIVE

To obtain more precise estimates of the association between thyroid cancer and benign thyroid diseases and to elucidate the role of potential confounders or effect modifiers.

METHODS

The original data from 12 case-control studies from the United States, Asia, and Europe were pooled. Based on 2,094 women and 425 men with cancer of the thyroid and, respectively, 3,248 and 928 control subjects, odds ratios (ORs) and the corresponding 95% confidence intervals (CIs) were obtained by conditional regression models, conditioning on study and age at diagnosis, and adjusting for age and radiotherapy.

RESULTS

A history of hypothyroidism was not associated with cancer risk (pooled ORs = 0.9, 95% confidence interval, CI: 0.7-1.3 in women and 1.7, 95% CI: 0.3-11.7 in men). ORs for hyperthyroidism were 1.4 (95% CI: 1.0-2.1) in women and 3.1 (95% CI: 1.0-9.8) in men. In women, however, risk was lower in the absence of or after allowance for history of goiter. Pooled ORs for a history of goiter were 5.9 (95% CI: 4.2-8.1) in women and 38.3 (95% CI: 5.0-291.2) in men. Risk for a history of benign nodules/adenomas was especially high (OR = 29.9, 95% CI: 14.5-62.0, in women; 18 cases versus 0 controls in men). The excess risk for goiter and benign nodules/adenomas was greatest within 2-4 years prior to thyroid cancer diagnosis, but an elevated OR was present 10 years or more before cancer.

CONCLUSIONS

Goiter and benign nodules/adenomas are the strongest risk factors for thyroid cancer, apart from radiation in childhood.