Risk of endometrial cancer in relationship to cigarette smoking: results from the EPIC study

Current epidemiologic evidence indicates that cigarette smoking reduces the risk of endometrial cancer. We examined data from the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort to analyze further aspects of the smoking-endometrial cancer relationship, such as possible modifying effects of menopausal status, HRT use, BMI and parity. In a total of 249,986 women with smoking exposure and menopausal status information, 619 incident endometrial cancer cases were identified during 1.56 million person-years of follow-up. Among postmenopausal women, the hazard ratio (HR) for current smokers versus never smokers was 0.70 (95% CI = 0.53-0.93), while it was 1.75 (95% CI = 1.13-2.70) among premenopausal women at recruitment. After adjustment for risk factors, the HR for postmenopausal women was slightly attenuated to 0.78 (95% CI = 0.59-1.03). No heterogeneity of effect was observed with HRT use or BMI. Among premenopausal women, current smokers of more than 15 cigarettes per day or who smoked for 30 years or more at the time of recruitment had a more than 2-fold increased risk of endometrial cancer compared to never smokers (HR = 2.54; 95% CI = 1.47-4.38 and HR = 2.23; 95% CI = 1.04-4.77, respectively). Past smoking was not associated with endometrial cancer risk, either among pre- or postmenopausal women. In this prospective study, we observed an increased risk of endometrial cancer with cigarette smoking in premenopausal women. The reduction of endometrial cancer risk observed among postmenopausal women does not have direct public health relevance since cigarette smoking is the main known risk factor for cancer.     

Physical activity and risk of endometrial adenocarcinoma in the Nurses' Health Study

Studies suggest that greater physical activity may reduce endometrial cancer risk. However, the role of the timing, duration and intensity of activity is unclear. We therefore examined recent and past recreational activities in relation to incident endometrial adenocarcinoma, and compared the importance of total and moderate‐ or vigorous‐intensity activities as well as walking. We analyzed data from 71,570 women in the Nurses' Health Study, a prospective cohort that assessed activity in 1986, with updates every 2–4 years. Cox proportional hazards models were used to estimate relative risks (RRs) and 95% confidence intervals (CIs). During follow‐up from 1986 to 2008 (1.2 million person‐years), 777 invasive endometrial adenocarcinoma cases were documented. In multivariable models, compared with <3 MET‐hr/week (<1 hr/week walking), women engaged in moderate (9 to <18 MET‐hr/week: RR = 0.61, 95% CI: 0.48–0.78) or high (≥27 MET‐hr/week: RR = 0.73, 95% CI: 0.58–0.92) amounts of recent total recreational activity were at reduced risk (p‐trend = 0.001). Past total activity was not associated with risk. Greater recent moderate‐ or vigorous‐intensity activity was associated with reduced risk (≥4 vs. 0 hr/week: RR = 0.65, 95% CI: 0.47–0.88, p‐trend = 0.002). Among women who did not perform any vigorous activity, recent walking was associated with reduced risk (≥3 vs. <0.5 hr/week: RR = 0.65, 95% CI: 0.45–0.93, p‐trend = 0.01), and faster walking pace was independently associated with risk reduction. After additional adjustment for body mass index, all associations were statistically non‐significant. Greater recent physical activity, including activity of moderate duration and intensity such as walking, may reduce endometrial adenocarcinoma risk. This relation is largely mediated or confounded by body mass index.     

Alcohol consumption and postmenopausal endometrial cancer: results from the Iowa Women's Health Study

At least three case-control studies have examined the association between alcohol consumption and endometrial cancer; two studies showed inverse associations, and a third a positive association. To our knowledge, no prospective studies of this association have been reported. The association between alcohol and endometrial cancer was examined in the Iowa Women's Health Study (United States), a prospective study of postmenopausal women. Information on alcohol consumption and other variables was obtained through a mailed questionnaire in January 1986. Through December 1990, 167 incident endometrial cancer cases occurred in the at-risk cohort of 25,170 women. Multivariate-adjusted relative risks (RR) and 95 percent confidence intervals (CI) were computed using Cox proportional hazards regression controlling for age, body mass index (BMI), parity, age at menopause, and noncontraceptive estrogen use, and to determine multiplicative interactions. The RRs of endometrial cancer associated with <4.0 and 4.0 g of alcohol per day compared with abstainers were 0.7 (CI=0.5–1.1) and 1.0 (CI=0.7–1.6), respectively. No statistically significant association between endometrial cancer and consumption of either beer, wine, or liquor was observed. There was no interaction between alcohol and any other endometrial cancer risk factors, including BMI or noncontraceptive estrogen use. These data do not support an association between alcohol and endometrial cancer among postmenopausal women.This project was supported by grant RO1-CA39742 to Dr Folsom from the US National Cancer Institute; the contents are solely the responsibility of the authors and do not necessarily represent the official views of the National Cancer Institute. Dr Gapstur was supported by NIH training grant T32-CA09607 to Dr Potter.     

Antioxidant intake and risk of endometrial cancer: Results from the Nurses' Health Study

To investigate the associations between antioxidant intake and risk of endometrial cancer, the authors analyzed data from the prospective Nurses' Health Study. From 1980 to 2006, 669 invasive adenocarcinoma cases were identified over 1.3 million person‐years of follow‐up. Information on dietary intake was collected in 1980 and updated every 2–4 years. Cox proportional hazard models were used to calculate the multivariate relative risks (RR), controlling for total energy and potential risk factors for endometrial cancer. Overall, the authors found no association between intakes of vitamins A, C, E or carotenoids from foods or supplements and cancer risk. The RR and 95% confidence intervals (CI) for the highest vs. lowest quintiles of vitamins A, C, E and total carotenoids were 1.09 (95% CI: 0.85–1.39), 0.98 (95% CI: 0.76–1.25), 1.07 (95% CI: 0.83–1.38) and 1.12 (95% CI: 0.86–1.45), respectively. Similarly, the use of multivitamins or specific vitamins A, C or E supplements was unassociated with risk. In subgroup analyses, several associations seemed to vary by postmenopausal hormone use. Our results suggest that there is no overall association between dietary antioxidant intake or use of antioxidant supplements with risk of endometrial cancer.     

Smoking cessation and lung cancer risk in an Asian population: Findings from the Singapore Chinese Health Study

Background:

Smoking cessation is an important strategy for reducing the harmful effects of tobacco, particularly in the prevention of lung cancer; however, prospective data on the impact of smoking cessation on lung cancer risk in Asian populations are limited.

Methods:

We studied a population-based cohort of Chinese men and women aged 45–74 years – participants of the Singapore Chinese Health Study. Information on smoking, lifestyle and dietary habits was collected at the time of recruitment in 1993–1998; and smoking status was assessed again at a second interview in 1999–2004 (mean interval 5.8 years). Participants were followed up to 31 December 2007, and incident cases of lung cancer were ascertained by linkage with population-wide registries.

Results:

Among 45 900 participants, there were 463 incident cases of lung cancer. Relative to current smokers, those who quit smoking subsequent to baseline assessment had a 28% decrease in the risk of lung cancer (adjusted hazard ratio (HR) 0.72; 95% CI (95% confidence interval): 0.53–0.98). The risk was less than half in ex-smokers who had quit before the first interview and maintained their status (HR 0.42; 95% CI: 0.32–0.56).

Conclusions:

Reduction in lung cancer incidence with smoking cessation in Asian populations is substantial and can be observed within a few years after quitting.     

The role of body weight in the relationship between physical activity and endometrial cancer: results from a large cohort of US women

Factors influencing circulating estrogen levels, insulin-mediated pathways or energy balance through obesity-related mechanisms, such as physical activity, have been proposed as potential risk factors for endometrial cancer. We examined measures of physical activity in relation to endometrial cancer risk in the American Cancer Society Cancer Prevention Study II Nutrition Cohort, a prospective study of cancer incidence and mortality, using information obtained at baseline in 1992. From 1992 to 2003, 466 incident endometrial cancers were identified among 42,672 postmenopausal women with intact uteri who were cancer-free at enrollment. Cox proportional hazards modeling was used to compute hazard rate ratios (RR) while adjusting for potential confounders. To assess the role of body mass index (BMI) in this relationship, we computed multivariate RR with and without adjustment for BMI and stratifying by BMI. All measures of physical activity and the avoidance of sedentary behavior were associated with lower endometrial cancer risk. Baseline recreational physical activity was associated with 33% lower risk (RR = 0.67, 95% CI 0.44-1.03 for 31.5+ vs. <7 MET-hr/week, trend p = 0.007) in the multivariate model without BMI. However, the trend was attenuated after further adjustment for BMI (trend p = 0.18). BMI significantly modified the association between physical activity and endometrial cancer risk (heterogeneity of trends p = 0.01). The inverse relationship was seen only among overweight or obese women (trend p = 0.003) and not in normal weight women (trend p = 0.51). In summary, light and moderate physical activity including daily life activities were associated with lower endometrial cancer risk in our study, especially among women who are overweight or obese.     

Anthropometric measures and epithelial ovarian cancer risk among Chinese women: results from the Shanghai Women's Health Study

Background:

Studies of anthropometric measures and ovarian cancer risk have predominantly included women of European descent with mixed findings.

Methods:

Data from the prospective Shanghai Women''s Health Study (SWHS) were used to evaluate associations between anthropometric measures and risk of epithelial ovarian cancer (EOC). Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated by Cox proportional hazards regression.

Results:

A total of 152 EOC cases occurred among 70 258 women. Increasing quartiles of weight, hip circumference, and weight gain during adulthood were associated with significantly increased EOC risks. Body mass index (BMI) was also associated; overweight (25⩽BMI<29.99) and obese women (BMI⩾30.0) had significantly increased risks (HR: 1.49, 95% CI: 1.05, 2.13, and HR: 2.42, 95% CI: 1.37, 4.28, respectively). No significant associations were observed for height, waist circumference, waist-to-hip ratio (WHR), and waist-to-height ratio (WHER).

Conclusion:

Results from this large prospective study of Chinese women support the hypothesis that general adiposity contributes to the aetiology of ovarian cancer.     

Fluid intake and risk of bladder cancer in the Nurses' Health Studies

Increase in fluid intake may reduce bladder cancer risk by decreasing the contact time between carcinogens in urine and bladder epithelium. However, this association has not been examined in a large cohort of women. The association between total fluid intake and bladder cancer risk in two large prospective women's cohorts with 427 incident bladder cancer cases was examined. Detailed information on total fluid intake was collected by repeated food frequency questionnaires over time. Multivariable relative risks (RRs) and 95% confidence intervals (95% CIs) were estimated by using Cox proportional hazards regression models. Results from the two cohorts were pooled together using the random‐effects model. Using the average values from the earliest two dietary assessments and lowest quartile as reference, a suggestive inverse association was observed between total fluid intake and overall bladder cancer risk (RR: 0.83, 95% CI: 0.61–1.12, p‐value for trend: 0.08), and invasive bladder cancer risk (RR: 0.47, 95% CI: 0.23–0.97, p‐value for trend: 0.04). Among heavy cigarette smokers, women with the highest quartile of total fluid intake had a 38% decrease in bladder cancer risk (RR: 0.62, 95% CI: 0.41–0.93, p‐value for trend: 0.02). The findings suggested that total fluid intake may reduce bladder cancer risk for female smokers, as well as reduce the risk of invasive bladder cancer.     

Body mass index and smoking-related lung cancer risk in the Singapore Chinese Health Study

Background:

Smokers with low body mass index (BMI) may be more susceptible to lung cancer.

Methods:

We prospectively examined the association between baseline BMI and lung cancer risk in the Singapore Chinese Health Study, a cohort of 63 257 Chinese enrolled between 1993 and 1998.

Results:

After adjustment for smoking intensity and duration, BMI was inversely associated with risk of lung cancer among current smokers (P for trend=0.0004). Current smokers at different dosage of smoking with low BMI had significantly higher risk for lung cancer than those with high BMI. Hazard ratios (95% confidence intervals) of lung cancer for heavy smokers with BMI of ⩾28, 24–<28, 20–<24, and <20 kg m⁻² were 6.37 (2.10–19.30), 9.01 (5.04–16.10), 8.53 (6.35–11.5), and 11.12 (6.60–18.70), respectively, as compared with nonsmokers. BMI had no modifying effects on lung cancer risk among nonsmokers and former smokers.

Conclusion:

Smokers with lower BMI may experience an enhanced risk of lung cancer. The findings have significant public-health implication given the increase in smoking prevalence in developing countries, where people still have relatively low BMI.     

Alcohol consumption and prostate cancer risk: results from the Melbourne collaborative cohort study

Although there is little evidence to support an association between alcohol consumption and prostate cancer risk, questions remain concerning the effect on aggressive and nonaggressive tumours and the pattern and type of alcohol consumed. In a prospective cohort of 16,872 men aged 27-70 years at recruitment and followed-up from 1994 to the end of 2003, 732 incident prostate cancers were identified through the local population cancer registry, including 132 aggressive cases and 53 prostate cancer deaths. Detailed information on alcohol consumption was taken at baseline by trained interviewers using a structured questionnaire. Overall, alcohol intake was not associated with prostate cancer incidence. Compared to abstainers, men consuming 1-19 g/d of alcohol had a slightly reduced incidence of aggressive prostate cancers (hazard ratio 0.67; 95% confidence interval (CI) 0.43, 1.06) and prostate cancer mortality (hazard ratio 0.56; 95% CI 0.28, 1.14), but their risk of nonaggressive prostate cancers was close to unity (hazard ratio 1.09; 95% CI 0.85, 1.40). No significant association with pattern of drinking or type of alcoholic beverage was found. Our results show that alcohol consumption does not influence overall prostate cancer incidence but we found suggestive evidence that alcohol consumption might decrease the incidence of aggressive prostate cancer and mortality.     

Smoking as an independent risk factor for hepatocellular carcinoma: the Singapore Chinese Health Study

Background:

Given the close correlation between smoking and alcohol intake in most epidemiologic studies, it is difficult to exclude the residual confounding effect of alcohol in the association between smoking and hepatocellular carcinoma (HCC).

Method:

We evaluated the association between smoking and risk of HCC in the Singapore Chinese Health Study, a prospective cohort with a low prevalence of alcohol intake. Information on cigarette smoking and alcohol consumption was obtained through in-person interviews conducted at enrolment.

Results:

After a mean of 11.5 years of follow-up, there were 394 incident cases of HCC. Participants who consumed more than two alcoholic drinks per day showed an increased risk for HCC (hazard ratio (HR)=2.24; 95% confidence interval (CI)=1.46–3.41). After adjusting for alcohol consumption and other potential confounders, current vs never smokers had a statistically significant, increased risk of HCC (HR=1.63; 95% CI=1.27–2.10) that was dose-dependent (number of cigarettes per day, P for trend<0.001). The observed tobacco–HCC association also was duration-dependent (years of smoking in ever smokers, P for trend=0.002). When we excluded daily drinkers from the analysis, all risk estimates remained essentially the same and statistically significant.

Conclusion:

Our findings strongly implicate tobacco smoke as a causal factor of HCC development.     

Contraceptive methods and ovarian cancer risk among Chinese women: A report from the Shanghai Women's Health Study

Oral contraceptive use is associated with reduced ovarian cancer risk; however, associations with other contraceptive methods, such as intrauterine device (IUD) and tubal ligation, are less clear. Women in China differ from western women in regard to mechanisms and duration of use of contraception. This study was undertaken to evaluate associations between contraceptive methods and ovarian cancer risk using data from the prospective Shanghai Women's Health Study. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated by Cox proportional hazards regression. A total of 174 epithelial ovarian cancer cases were found to occur among 70,259 women who were followed‐up for a total of 888,258 person‐years. The majority of women had ever used any contraception (77.0%), including IUD (55.6%), oral contraceptive (20.4%), tubal ligation (14.7%) or contraceptive shots (2.6%). Ever use of any contraception was associated with a nonsignificant reduction in ovarian cancer risk (HR: 0.86, 95% CI: 0.60–1.24). Longer duration of IUD use was associated with lower ovarian cancer risk (p‐value for trend = 0.04). Compared with never users, women with durations of IUD use longer than the median (20 years) were 38% less likely to develop ovarian cancer (HR: 0.62, 95% CI: 0.40–0.97). Based on the high prevalence and long duration of IUD use among Chinese women, we estimate a preventive fraction of 9.3%, corresponding to approximately 16 ovarian cancer cases. High prevalence of long‐term IUD use may, therefore, contribute to the low incidence of ovarian cancer observed in China.     

Long‐term dietary acrylamide intake and risk of endometrial cancer in a prospective cohort of Swedish women

Acrylamide has been found in foods heated at high temperatures and there is evidence of carcinogenicity of acrylamide in experimental animals. However, the potential health risks of dietary acrylamide intake in humans remain uncertain. We examined the association between dietary acrylamide intake and the incidence of endometrial cancer among 61,226 participants of the Swedish Mammography Cohort who were cancer‐free at enrollment in 1987–1990 and completed a food frequency questionnaire at baseline and again in 1997. Cox proportional hazards models were used to estimate rate ratios with 95% confidence intervals, adjusted for endometrial cancer risk factors. During a mean follow‐up of 17.7 years, a total of 687 incident cases of endometrial adenocarcinoma were diagnosed in the cohort. We found no association between long‐term acrylamide intake and risk of endometrial cancer. The multivariate rate ratio of endometrial cancer for women in the highest quartile of acrylamide intake (mean, 33.8 μg/day) compared to those in the lowest quartile (mean, 15.9 μg/day) was 0.96 (95% CI, 0.76–1.21). The association did not vary materially by smoking status. In conclusion, these findings do not support the hypothesis that dietary acrylamide intake is positively associated with risk of endometrial cancer, at least not within the ranges of acrylamide consumed in this population. © 2008 Wiley‐Liss, Inc.     

Alcohol consumption and endometrial cancer risk: the multiethnic cohort

The role of alcohol intake in the etiology of endometrial cancer is unclear. We examined the impact of alcohol intake on endometrial cancer risk among 41,574 postmenopausal African-American, Japanese-American, Latina, Native-Hawaiian and White women recruited to the prospective Multiethnic Cohort Study in 1993-1996. During an average of 8.3 years of follow-up, 324 incident invasive endometrial cancer cases were identified among these women. Data on alcohol intake and endometrial cancer risk factors were obtained from the baseline questionnaire. Relative risks (RRs) and 95% confidence intervals (CIs) for endometrial cancer associated with alcohol intake were estimated using log-linear (Cox) proportional hazard models stratified by age, year of recruitment, ethnicity and study center, and adjusted for several confounding factors. Increased alcohol consumption was associated with increased risk (p trend = 0.013). Compared to nondrinkers, women consuming >or=2 drinks/day had a multivariate RR of 2.01 (95% CI: 1.30, 3.11). There was no increase in risk associated with <1 drink/day (RR = 1.01; 95% CI: 0.77, 1.33) and 1 to <2 drinks/day (RR = 1.09; 95% CI: 0.62, 1.93). There was no clear effect modification by body mass index, postmenopausal hormone use, parity, oral contraceptive use or smoking status, though our power to detect such interactions was limited. Our results suggest that only alcohol consumption equivalent to 2 or more drinks per day increases risk of endometrial cancer in postmenopausal women.     

A prospective cohort study of cigarette smoking and the risk of endometrial cancer

Case-control studies have shown inverse associations between cigarette smoking and endometrial cancer risk. However, two small prospective cohort studies have not clearly supported an association. Moreover, quantitative measures of smoking have been examined infrequently. Our aim was to study the association between smoking and endometrial cancer risk in a large prospective cohort. We used proportional hazards models to estimate hazard ratios relating cigarette smoking to endometrial cancer risk among 70 591 women aged 40-59 years at recruitment into a randomised controlled trial of mammography screening for breast cancer. During an average of 10.6 years of follow-up (751 833 person-years), a total of 403 women were diagnosed with incident endometrial cancer. We found that a reduced endometrial cancer risk was evident only among women who currently smoked 20 cigarettes per day or more (hazard ratio=0.62, 95% CI=0.42-0.92, P for trend=0.03). There was some suggestion of an inverse association with smoking duration, but this was less clear. The association did not vary with menopausal status, relative body weight, or the use of hormone replacement therapy, but it appeared to be stronger among parous than nulliparous women. The underlying biological mechanisms of this association remain unclear.     

Long-term and baseline recreational physical activity and risk of endometrial cancer: the California Teachers Study

Background:

Physical activity may be associated with decreasing endometrial cancer risk; it remains unclear whether the association is modified by body size.

Methods:

Among 93 888 eligible California Teachers Study participants, 976 were diagnosed with incident endometrial cancer between 1995–1996 and 2007. Cox proportional hazards regression methods were used to estimate relative risks (RRs) and 95% confidence intervals (CIs) for endometrial cancer associated with long-term (high school through age 54 years) and baseline (3 years prior to joining the cohort) strenuous and moderate recreational physical activity, overall and by body size.

Results:

Increased baseline strenuous recreational physical activity was associated with decreased endometrial cancer risk (P_trend=0.006) with approximately 25% lower risk among women exercising >3 h per week per year than among those exercising <1/2 h per week per year (RR, 0.76; 95% CI, 0.63–0.92). This inverse association was observed among overweight/obese women (body mass index ≥25 kg m⁻²; P_trend=0.006), but not among thinner women (P_trend=0.12). Baseline moderate activity was associated with lower risk among overweight/obese women.

Conclusion:

Increasing physical activity, particularly strenuous activity, may be a lifestyle change that overweight and obese women can implement to reduce their endometrial cancer risk.     

Alcohol and endometrial cancer risk in the NIH‐AARP diet and health study

Previous investigations have provided conflicting results regarding whether alcohol consumption affects endometrial cancer risk, although in many of these studies the highest category of alcohol intake examined was limited. Further, most were unable to resolve how alcohol associations are affected by beverage type, the presence of other endometrial cancer risk factors, or tumor characteristics. To address these issues, we prospectively evaluated the association between alcohol intake and incident endometrial cancer (n = 1,491) in a cohort of 114,414 US women enrolled in the NIH‐AARP Diet and Health Study. We calculated relative risks (RR) and 95% confidence intervals (CI) using Cox proportional hazards regression. After adjustment for age, body mass index (BMI), smoking and other potential confounders, the multivariable RRs (and 95% CIs) compared with nondrinkers were 0.97 (0.87–1.09) for >0–<12 g of alcohol/day, 1.06 (0.87–1.31) for 12–<24 g/day and 0.93 (0.71–1.20) for ≥24 g/day (p trend = 0.90). There was, however, some suggestion of higher risks associated with alcohol consumption among lean women (BMI, <25) and users of menopausal hormone therapy, with significant interactions with both parameters (respective interaction p‐values of 0.002 and 0.005). The relationship was also enhanced, albeit nonsignificantly so, for low grade cancers. Our results do not support that alcohol is a strong contributor to endometrial cancer risk, but slight risk increases may prevail among some users or for selected tumor characteristics.     

Dietary glycemic index,glycemic load,and endometrial cancer risk: The Japan Public Health Center-based Prospective Study

Evidence supporting the association of glycemic index (GI) and glycemic load (GL) with the risk of endometrial cancer is controversial and reports from Asia were limited. Therefore, we aimed to investigate the association in Japanese women. We evaluated 52 460 women in the Japan Public Health Center-based Prospective Study aged 45-74 years who responded to the 5-year follow-up survey. GI and GL were calculated from a validated food frequency questionnaire, and the participants were divided into three groups by GI and GL. The hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated with the Cox proportional hazard model adjusted for potential confounding factors. As a result, within 15.5 years of follow-up, 166 new cases of endometrial cancer were identified. Compared with the lowest GI and GL tertile groups, the HR of the risk of endometrial cancer in the highest GI tertile group was 0.80 (95% CI, 0.53-1.20; P_trend = .33), and that of the highest GL tertile group was 0.79 (95% CI, 0.52-1.19; P_trend = .82). The results were unchanged after stratification by body mass index, coffee consumption, and history of diabetes. In conclusion, we did not find any significant association between GI and GL with the risk of endometrial cancer. Further research is required to clarify the association.     

Dietary intake of acrylamide and endometrial cancer risk in the European Prospective Investigation into Cancer and Nutrition cohort

Background:

Three prospective studies have evaluated the association between dietary acrylamide intake and endometrial cancer (EC) risk with inconsistent results. The objective of this study was to evaluate the association between acrylamide intake and EC risk: for overall EC, for type-I EC, and in never smokers and never users of oral contraceptives (OCs). Smoking is a source of acrylamide, and OC use is a protective factor for EC risk.

Methods:

Cox regression was used to estimate hazard ratios (HRs) for the association between acrylamide intake and EC risk in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. Acrylamide intake was estimated from the EU acrylamide monitoring database, which was matched with EPIC questionnaire-based food consumption data. Acrylamide intake was energy adjusted using the residual method.

Results:

No associations were observed between acrylamide intake and overall EC (n=1382) or type-I EC risk (n=627). We observed increasing relative risks for type-I EC with increasing acrylamide intake among women who both never smoked and were non-users of OCs (HR_Q5vsQ1: 1.97, 95% CI: 1.08–3.62; likelihood ratio test (LRT) P-value: 0.01, n=203).

Conclusions:

Dietary intake of acrylamide was not associated with overall or type-I EC risk; however, positive associations with type I were observed in women who were both non-users of OCs and never smokers.     

Cigarette smoking,alcohol intake,and risk of glioma in the NIH-AARP Diet and Health Study

Background:

Although cigarette smoking and alcohol drinking increase the risk of several cancers and certain components of cigarette smoke and alcohol can penetrate the blood–brain barrier, it remains unclear whether these exposures influence the risk of glioma.

Methods:

We examined the associations between cigarette smoking, alcohol intake, and risk of glioma in the National Institutes of Health-AARP Diet and Health Study, a prospective study of 477 095 US men and women ages 50–71 years at baseline. Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated using models with age as the time metric and adjusted for sex, race/ethnicity, education, and marital status.

Results:

During a median 10.5 person-years of follow-up, 492 men and 212 women were diagnosed with first primary glioma. Among men, current, heavier smoking was associated with a reduced risk of glioma compared with never smoking, but this was based on only nine cases. No associations were observed between smoking behaviours and glioma risk in women. Greater alcohol consumption was associated with a decreased risk of glioma, particularly among men (>2 drinks per day vs <1 drink per week: HR=0.67, 95% CI=0.51–0.90).

Conclusion:

Smoking and alcohol drinking do not appear to increase the risk of glioma.