Search

Epidemiological evidence regarding the association between carbohydrate intake, glycaemic load (GL) and glycaemic index (GI) and risk of ovarian cancer has been mixed. Little is known about their impact on ovarian cancer risk in African-American women. Associations between carbohydrate quantity and quality and ovarian cancer risk were investigated among 406 cases and 609 controls using data from the African American Cancer Epidemiology Study (AACES). AACES is an ongoing population-based case–control study of ovarian cancer in African-Americans in the USA. Cases were identified through rapid case ascertainment and age- and site-matched controls were identified by random-digit dialling. Dietary information over the year preceding diagnosis or the reference date was obtained using a FFQ. Multivariable logistic regression models were used to estimate odds ratios and 95 % CI adjusted for covariates. The OR comparing the highest quartile of total carbohydrate intake and total sugar intake v. the lowest quartile were 1·57 (95 % CI 1·08, 2·28; Ptrend=0·03) and 1·61 (95 % CI 1·12, 2·30; Ptrend<0·01), respectively. A suggestion of an inverse association was found for fibre intake. Higher GL was positively associated with the risk of ovarian cancer (OR 1·18 for each 10 units/4184 kJ (1000 kcal); 95 % CI 1·04, 1·33). No associations were observed for starch or GI. Our findings suggest that high intake of total sugars and GL are associated with greater risk of ovarian cancer in African-American women. [ABSTRACT FROM AUTHOR]

Background: Ovarian cancer (OVCA) is the leading cause of death from gynecological cancer, with poorer survival for African American (AA) women compared to whites. However, little is known about risk factors for OVCA in AA. To study the epidemiology of OVCA in this population, we started a collaborative effort in 10 sites in the US. Here we describe the study and highlight the challenges of conducting a study of a lethal disease in a minority population. Methods: The African American Cancer Epidemiology Study (AACES) is an ongoing, population-based case-control study of OVCA in AA in 10 geographic locations, aiming to recruit 850 women with invasive epithelial OVCA and 850 controls age- and geographically-matched to cases. Rapid case ascertainment and random-digit-dialing systems are in place to ascertain cases and controls, respectively. A telephone survey focuses on risk factors as well as factors of particular relevance for AAs. Food-frequency questionnaires, follow-up surveys, biospecimens and medical records are also obtained. Results: Current accrual of 403 AA OVCA cases and 639 controls exceeds that of any existing study to date. We observed a high proportion (15%) of deceased non-responders among the cases that in part is explained by advanced stage at diagnosis. A logistic regression model did not support that socio-economic status was a factor in advanced stage at diagnosis. Most risk factor associations were in the expected direction and magnitude. High BMI was associated with ovarian cancer risk, with multivariable adjusted ORs and 95% CIs of 1.50 (0.99-2.27) for obese and 1.27 (0.85-1.91) for morbidly obese women compared to normal/underweight women. Conclusions: AACES targets a rare tumor in AAs and addresses issues most relevant to this population. The importance of the study is accentuated by the high proportion of OVCA cases ascertained as deceased. Our analyses indicated that obesity, highly prevalent in this population (>60% of the cases), was associated with increased OVCA risk. While these findings need to be replicated, they suggest the potential for an effective intervention on the risk in AAs. Upon completion of enrollment, AACES will be the largest epidemiologic study of OVCA in AA women. [ABSTRACT FROM AUTHOR]

The question of whether cigarette smoking was associated with lung cancer was central to the expansion of epidemiology into the study of chronic diseases in the 1950s. The culmination of this era was the 1964 report of the Advisory Committee to the Surgeon General, a landmark document that included an objective synthesis of the evidence of the health consequences of smoking according to causal criteria. The report concluded that cigarette smoking was a cause of lung cancer in men and sufficient in scope that “remedial action” was warranted at the societal level. The 2014 Surgeon General's report commemorates the 50th anniversary of the 1964 report. The evidence on the health consequences of smoking has been updated many times in Surgeon General's reports since 1964. These have summarized our increasingly greater understanding of the broad spectrum of the deleterious health effects of exposure to tobacco smoke across most major organ systems. In turn, this evidence has been translated into tobacco control strategies implemented to protect the public's health. The Surgeon General report process is an enduring example of evidence-based public health in practice. Substantial progress has been made, but cigarette smoking remains one of the most pressing global health issues of our time. [ABSTRACT FROM PUBLISHER]

Background: Several previous studies have reported inverse associations between cigarette smoking and melanoma. Often these studies have not adjusted for ultraviolet (UV) exposure history, skin type, or number of blistering sunburns, which could confound the observed associations between cigarette smoking and melanoma. Objective: We sought to assess whether this reported inverse association persists after adjusting for UV exposure, skin type, and number of blistering sunburns. Methods: We conducted a population-based case-control study (82 patients with melanoma, 164 control subjects). Two control subjects were matched to each patient by age, sex, race, and skin type. Conditional logistic regression models were fit to assess the association between cigarette smoking history and melanoma, with additional adjustments for UV exposure and sunburns. Results: Compared with never smoking, both former (odds ratio 0.43, 95% confidence interval 0.18-1.04) and current (odds ratio 0.65, 95% confidence interval 0.19-2.24) smoking were inversely associated with melanoma, but the associations were not statistically significant. Limitations: The number of cutaneous nevi was not assessed in this study. In addition, the relatively small number of patients limits the statistical precision of the observed associations. Conclusions: After matching for age, sex, race, and skin type, and further adjusting for UV exposure and number of sunburns, cigarette smoking was not statistically significantly associated with melanoma risk, but the results were consistent with previous observations of an inverse association. [Copyright &y& Elsevier]

Background: Epidemiological evidence evaluating the association between secondhand smoke exposure and diseases of the upper airway in adults is limited by a small number of studies and a lack of established protocols. This study was designed to optimize a research protocol on secondhand tobacco smoke exposure and chronic rhinosinusitis for a future population-based case-control study in Washington County, Maryland, using a participatory research model. Methods: We conducted three focus groups with health professionals, community members, and research practitioners for protocol development; 10 one-on-one cognitive testings with community members for protocol refinement; and a pilot testing of the full study protocol (10 cases and 10 controls) for full evaluation of the study protocol. Results: Health professionals recommended, among other themes, enrolling patients with confirmed chronic rhinosinusitis (minimum 12-week symptom duration and objective inflammation). Community members and research practitioners discussed optimal strategies for participant recruitment and interviewing. The protocol, revised with the focus group’s feedback, was further evaluated in one-on-one sessions with 10 Washington County residents (3 with chronic rhinosinusitis). In the pilot study, 10 nonsmoking chronic rhinosinusitis cases (5 clinic based and 5 community based) and their community-based age, sex, and former/never smoking-matched controls were recruited. Sinonasal symptoms scores were higher in cases than controls but similar for clinic versus community-based cases. Conclusion: This protocol development framework involving stakeholders resulted in a comprehensive questionnaire that was successfully evaluated during a pilot study and is now ready to be used in population-based and clinical epidemiological studies of chronic rhinosinusitis in adults. [ABSTRACT FROM AUTHOR]

Candidate gene association studies (CGAS) are a useful epidemiologic approach to drawing inferences about relations between genes and disease, especially when experimental data support the involvement of specific biochemical pathways. The value of CGAS is apparent when allele frequencies are low, effect sizes are small, or the study population is limited or unique. CGAS is also valuable for validating previous reports of genetic associations with disease in different populations. Despite the many advantages, the information generated from CGAS is sometimes compromised because of either inefficient study design or suboptimal analytical approaches. Here the authors discuss issues related to the study design and statistical analyses of CGAS that can help to optimize their usefulness and information content. These issues include judicious hypothesis-driven selection of biochemical pathways, genes, and single nucleotide polymorphisms, as well as appropriate quality control and analytical procedures for measuring main effects and for evaluating environmental exposure modifications and interactions. A study design algorithm using the example of DNA repair genes and cancer is presented for purposes of illustration. [ABSTRACT FROM PUBLISHER]

Background: Nicotine replacement therapy (NRT) has been shown to assist smokers to stop smoking in randomized trials, but little is known about its use in the general population. Methods: As part of ongoing follow-up of a cohort established in 1989 in Washington County, Maryland, a questionnaire mailed in 1998 included a question about ever use of the two NRT products then available over-the-counter: nicotine gum and nicotine patch. This study reports on ever use of NRT among the 1,954 respondents who were current smokers in 1989 and subsequently provided data on NRT use and smoking habits in 1998. Results: Overall, 36% of the smokers in 1989 had ever used NRT in some form by 1998; 10% used gum only, 16% used patch only, and 10% used both gum and patch. Number of cigarettes smoked per day at baseline was the strongest predictor of ever use of NRT (Ptrend < 0.001). Compared to nonusers, ever users of NRT were more likely to have more than 12 years of education (p < 0.01) and be 25-54 years old at baseline (p < 0.001). When NRT use was assessed in relation to smoking status in 1998, 30% of NRT ever users compared to 39% of nonusers had quit smoking (p < 0.01). Among persistent smokers, the likelihood of reducing the number of cigarettes smoked per day was similar between NRT ever users (40%) and nonusers (41%). Conclusions: Ever use of NRT was common among this cohort of smokers, particularly among heavy smokers. Compared to nonusers, ever users of NRT were less likely to have stopped smoking and equally likely to cut down the frequency of smoking. This may reflect a tendency to turn to NRT for help after failing to quit by other means. [ABSTRACT FROM AUTHOR]

N-acetyltransferases (NATs) are important catalytic enzymes that metabolize carcinogenic arylamines. NAT2 genotype might modify the role of cigarette smoking, a source of arylamine exposure, in breast cancer. We conducted a nested case-control study to investigate the association between NAT2 genotype, smoking and breast cancer risk among women (110 cases, 113 matched controls) from the CLUE II cohort in Washington County, MD. Compared to women with the slow acetylator genotype, the main effects odds ratios (OR) for NAT2 were 1.4 for the intermediate acetylator genotype (95% confidence limits (CL) 0.7, 2.7) and 3.6 for the homozygous rapid acetylator genotype (95% CL 1.1, 11.4) (P for trend=0.05). Smoking was associated in the direction of increased breast cancer risk in slow acetylators (e.g., >15 pack-years versus never smokers OR 2.0; 95% CL 0.7, 5.8) but not in rapid acetylators. These associations were not statistically significant in the total study population, but a statistically significant interaction between smoking and NAT2 acetylator status was present in postmenopausal women. The main effect of NAT2 in the direction of increased risk suggests that exposures to NAT2-activated carcinogens other than cigarette smoke may be important in this study population. The results for smoking were consistent with an inactivation role for NAT2 in breast cancer. [Copyright &y& Elsevier]

We explored differences in prognostic ability for mortality of the established and validated Charlson comorbidity index with two other comorbidity indexes developed for this study. Our study was limited to persons diagnosed with HNCA between 1985 and 1993 in a database formed by a linkage of files from the National Cancer Institute''s Surveillance, Epidemiology, and End Results Program with Health Care Finance Administration Medicare files (n=9386). Adjusted relative risks (RR) and 95% confidence intervals (95%CI) for comorbidity index scores of 1 or more compared to 0 were (RR=1.50, 95% CI 1.43–1.68) Charlson index, (RR=1.53 95% CI 1.42–1.66) HNCA index, and (RR=1.49, 95% CI 1.32–1.68) ATC index, respectively. The Charlson and HNCA indexes displayed dose-response patterns (P-value for trend <0.0001). Although the ATC index appears promising, the HNCA and Charlson indexes had similar adjusted RR''s, dose-response patterns, P-values, and chi-square scores and appear particularly well-suited to the measurement of comorbidity. [ABSTRACT FROM AUTHOR]

Background Ever since a lung cancer epidemic emerged in the mid-1900s, the epidemiology of lung cancer has been intensively investigated to characterize its causes and patterns of occurrence. This report summarizes the key findings of this research. Methods A detailed literature search provided the basis for a narrative review, identifying and summarizing key reports on population patterns and factors that affect lung cancer risk. Results Established environmental risk factors for lung cancer include smoking cigarettes and other tobacco products and exposure to secondhand tobacco smoke, occupational lung carcinogens, radiation, and indoor and outdoor air pollution. Cigarette smoking is the predominant cause of lung cancer and the leading worldwide cause of cancer death. Smoking prevalence in developing nations has increased, starting new lung cancer epidemics in these nations. A positive family history and acquired lung disease are examples of host factors that are clinically useful risk indicators. Risk prediction models based on lung cancer risk factors have been developed, but further refinement is needed to provide clinically useful risk stratification. Promising biomarkers of lung cancer risk and early detection have been identified, but none are ready for broad clinical application. Conclusions Almost all lung cancer deaths are caused by cigarette smoking, underscoring the need for ongoing efforts at tobacco control throughout the world. Further research is needed into the reasons underlying lung cancer disparities, the causes of lung cancer in never smokers, the potential role of HIV in lung carcinogenesis, and the development of biomarkers. [ABSTRACT FROM AUTHOR]

Abstract: Exposure to inorganic arsenic via drinking water is a growing public health concern. We conducted a systematic review of the literature examining the association between arsenic in drinking water and the risk of lung cancer in humans. Towards this aim, we searched electronic databases for articles published through April 2006. Nine ecological studies, two case–control studies, and six cohort studies were identified. The majority of the studies were conducted in areas of high arsenic exposure (100μg/L) such as southwestern Taiwan, the Niigata Prefecture, Japan, and Northern Chile. Most of the studies reported markedly higher risks of lung cancer mortality or incidence in high arsenic areas compared to the general population or a low arsenic exposed reference group. The quality assessment showed that, among the studies identified, only four assessed arsenic exposure at the individual level. Further, only one of the ecological studies presented results adjusted for potential confounders other than age; of the cohort and case–control studies, only one-half adjusted for cigarette smoking status in the analysis. Despite these methodologic limitations, the consistent observation of strong, statistically significant associations from different study designs carried out in different regions provide support for a causal association between ingesting drinking water with high concentrations of arsenic and lung cancer. The lung cancer risk at lower exposure concentrations remains uncertain. [Copyright &y& Elsevier]