Recreational physical activity and risk of prostate cancer in a large cohort of U.S. men.

Physical activity has been proposed as a modifiable risk factor for prostate cancer because of its potential effects on circulating hormones such as testosterone and insulin. We examined the association of various measures of physical activity with prostate cancer risk among men in the American Cancer Society Cancer Prevention Study II Nutrition Cohort, a large prospective study of U.S. adults. Information on recreational physical activity was obtained from a self-administered questionnaire completed at cohort enrollment in 1992/1993, as well as from a questionnaire completed as part of an earlier study in 1982. During the 9-year prospective follow-up, 5,503 incident prostate cancer cases were identified among 72,174 men who were cancer-free at enrollment. Cox proportional hazards modeling was used to compute hazard rate ratios (RR) for measures of recreational physical activity and to adjust for potential confounding factors. We observed no difference in risk of prostate cancer between men who engaged in the highest level of recreational physical activity (>35 metabolic equivalent-hours/wk) and those who reported no recreational physical activity at baseline (RR, 0.90; 95% confidence interval, 0.78-1.04; P for trend = 0.31). We also did not observe an association between prostate cancer and recalled physical activity at age 40 or exercise reported in 1982. However, the incidence of aggressive prostate cancer was inversely associated with >35 metabolic equivalent-hours/wk of recreational physical activity compared with that in men who reported no recreational physical activity (RR, 0.69; 95% confidence interval, 0.52-0.92; P for trend = 0.06). Our findings are consistent with most previous studies that found no association between recreational physical activity and overall prostate cancer risk but suggest physical activity may be associated with reduced risk of aggressive prostate cancer.     

Diabetes and risk of endometrial cancer: a population-based prospective cohort study.

Although there is accumulating evidence that hyperinsulinemia in the context of insulin resistance is associated with carcinogenesis, only one prospective study of endometrial cancer incidence, in relation to diabetes, addressed this issue and showed no significant positive association. No previous study has investigated whether physical activity can modify the association between diabetes and endometrial cancer. We examined the association between diabetes and incidence of endometrial cancer and the potential effect modification by obesity and physical activity in the Swedish Mammography Cohort, a prospective cohort of 36,773 women, including 225 incident endometrial adenocarcinoma cases. After adjustments, the relative risk (RR) for endometrial cancer among women with diabetes comparing with nondiabetic women was 1.94 [95% confidence interval (95% CI), 1.23-3.08]. Among obese diabetics, the RR was 6.39 (95% CI, 3.28-12.06) compared with nonobese nondiabetic women. Among diabetics with low physical activity, the RR for endometrial cancer was 2.80 (95% CI, 1.62-4.85) compared with physically active nondiabetic women. Obese diabetics with low physical activity had a RR of 9.61 (95% CI, 4.66-19.83) compared with normal weight nondiabetic women with high physical activity. Diabetes was associated with a 2-fold increased risk, and combination of diabetes with obesity and low physical activity was associated with a further increased risk for endometrial cancer. Interventions to reduce body weight and increase physical activity may have important implications in terms of prevention of endometrial cancer and future management of diabetic subjects.     

Physical activity and risk of endometrial cancer: a population-based prospective cohort study.

Physical activity is involved in the regulation of metabolic and hormonal pathways and is one of the factors important for the maintenance of body weight; obesity is a risk factor for endometrial cancer. A connection between physical activity and endometrial cancer risk through hormonal mechanisms, possibly mediated by body weight, is biologically plausible. Only one study has investigated total physical activity, and no previous study has examined leisure time inactivity directly. We investigated the association of total physical activity and different types of physical activity with risk of endometrial cancer in the Swedish Mammography Cohort, a population-based prospective cohort, including 33,723 women and 199 endometrial cancer cases. After adjustments for potential confounders (age, body mass index, parity, history of diabetes, total fruit and vegetable intake, and education), the relative risks for endometrial cancer for the second to fourth quartile of total physical activity compared with the lowest one were 0.80 [95% confidence interval (95% CI), 0.54-1.18], 0.87 (95% CI, 0.59-1.28), and 0.79 (95% CI, 0.53-1.17). High leisure time inactivity (watching TV/sitting >or=5 hours daily) compared with low was associated with increased risk of endometrial cancer (relative risk, 1.66; 95% CI, 1.05-2.61). The associations were not modified by body mass index. Findings from this study suggest that total physical activity is weakly inversely associated with endometrial cancer risk and that leisure time inactivity is statistically significantly associated with increased risk for endometrial cancer.     

Dietary folate consumption and risk of ovarian cancer: a prospective cohort study.

Deficient dietary folate intake may be associated with increased cancer risk in humans owing to DNA damage resulting from impaired nucleotide excision repair. It is conceivable that an association with folate may be modified by alcohol and/or methionine intake given that alcohol consumption and low methionine intakes both increase dietary folate requirements. In the cohort study reported here, we examined the association between dietary folate intake and ovarian cancer risk, overall and within strata defined by alcohol and methionine intakes. The investigation was conducted in 49 613 Canadian women who were participants in the National Breast Screening Study and who completed self-administered lifestyle and food frequency questionnaires between 1980 and 1985. Linkages to cancer and national mortality databases yielded data on cancer incidence and deaths among cohort members, with follow-up ending between 1998 and 2000. During a mean 16.4 years of follow-up, we observed 264 incident ovarian cancer cases among 48 766 women for whom data were available. Dietary folate intake was associated with a 25% decrease in risk of ovarian cancer for the highest versus the lowest quartile level of intake (hazard ratio=0.75, 95% confidence interval=0.42-1.34, Ptrend=0.25). On stratification by alcohol intake, dietary folate was not associated with ovarian cancer risk among women consuming <4 g/day of alcohol, but there was some suggestion of reduced risk at relatively high levels of folate intake among women consuming > or =4 g/day of alcohol/day (Ptrend=0.09; Pinteraction=0.22). The association between folate and ovarian cancer risk did not vary by strata of methionine intake (Pinteraction=0.98). Our findings, while not statistically significant, suggest that relatively high dietary folate intake may be associated with a reduction in ovarian cancer risk among women with relatively high alcohol consumption and among those with relatively high methionine intake.     

Cholesterol-lowering drugs and advanced prostate cancer incidence in a large U.S. cohort.

BACKGROUND: 3-Hydroxy-3-methylglutaryl CoA reductase inhibitors, commonly known as statins, account for the great majority of cholesterol-lowering drug use in the United States. Long-duration statin use was associated with substantially reduced risk of advanced prostate cancer in a recent large prospective study. METHODS: We examined the association between use of cholesterol-lowering drugs and prostate cancer incidence by disease stage and grade among 55,454 men in the Cancer Prevention Study II Nutrition Cohort. Proportional hazards modeling was used to calculate RRs. RESULTS: During follow-up from 1997 to 2003, we identified 3,413 cases of incident prostate cancer, including 317 cases of advanced prostate cancer. After adjustment for age, history of prostate-specific antigen testing, and other potential prostate cancer risk factors, current use of cholesterol-lowering drugs for 5 or more years was not associated with overall prostate cancer incidence (multivariate adjusted rate ratio, 1.06; 95% confidence interval, 0.93-1.20), but was associated with a marginally statistically significant reduction in risk of advanced prostate cancer (rate ratio, 0.60; 95% confidence interval, 0.36-1.00). CONCLUSION: These results provide some support for the hypothesis that long-term statin use is associated with reduced risk of advanced prostate cancer.     

Risk of cancer in a large cohort of U.S. veterans with diabetes

Prior studies of cancer risk among diabetic men have reported inconsistent findings. The aim of this study was to assess the risk of cancer among a large cohort (n = 4,501,578) of black and white U.S. veterans admitted to Veterans Affairs hospitals. The cancer risk among men with diabetes (n = 594,815) was compared to the risk among men without diabetes (n = 3,906,763). Poisson regression was used to estimate adjusted relative risks (RRs) and 95% confidence intervals (CIs). Overall, men with diabetes had a significantly lower risk of cancer (RR = 0.93, 95%CI = 0.93–0.94). Men with diabetes, however, had increased risks of cancers of the liver (RR = 1.95, 95%CI = 1.82–2.09), pancreas (RR = 1.50, 95%CI = 1.42–1.59), biliary tract (RR = 1.41, 95%CI = 1.22–1.62), colon (RR = 1.20, 95%CI = 1.16–1.25), rectum (RR = 1.12, 95%CI = 1.07–1.18), and kidney (RR = 1.09, 95%CI = 1.03–1.16), as well as leukemia (RR = 1.14, 95%CI = 1.08–1.21) and melanoma (RR = 1.13, 95%CI = 1.03–1.24). In contrast, men with diabetes had decreased risks of cancers of the prostate (RR = 0.89, 95%CI = 0.87–0.91), brain (RR = 0.91, 95% CI = 0.82–0.99), buccal cavity (RR = 0.85, 95%CI = 0.82–0.89), lung (RR = 0.79, 95%CI = 0.77–0.80), esophagus (RR = 0.77, 95%CI = 0.72–0.82), and larynx (RR = 0.76, 95%CI = 0.71–0.80). These findings indicate that black and white men with diabetes are at significantly lower risk of total cancer and of two of the most common cancers among U.S. males; lung and prostate cancers. These decreased risks were offset, however, by increased risks of cancer at several sites. Hyperinsulinemia may explain the increased risks of the digestive cancers, while lower testosterone levels, in the case of prostate cancer, and higher BMI, in the case of lung cancer, may explain the decreased risks of those tumors.     

Dietary fiber intake and ovarian cancer risk: a prospective cohort study

There is some evidence from case–control studies that dietary fiber intake might be inversely associated with ovarian cancer risk, but there are limited prospective data. Therefore, we examined ovarian cancer risk in association with intake of dietary fiber in a prospective cohort of 49,613 Canadian women enrolled in the National Breast Screening Study (NBSS), who completed a self-administered food frequency questionnaire between 1980 and 1985. Linkages to national mortality and cancer databases yielded data on deaths and cancer incidence, with follow-up ending between 1998 and 2000. Data from the food frequency questionnaire were used to estimate intake of total dietary fiber, of fiber fractions, and of fiber from various sources. Cox proportional hazards models were used to estimate hazard ratios (HR) and 95% confidence intervals (CI) for the association between energy-adjusted quartile levels of fiber intake and ovarian cancer risk. During a mean 16.4 years of follow-up, we observed 264 incident ovarian cancer cases. Total dietary fiber and fiber fractions were not associated with ovarian cancer risk in this study population.     

Infertility and risk of fatal ovarian cancer in a prospective cohort of US women

Objectives: It is difficult to separate the possible role of fertility drugs from underlying infertility as risk factors for ovarian cancer. The present study examined the relationship between self-reported infertility and death from ovarian cancer among married women unlikely to have been exposured to fertility drugs.Methods: Women were selected for study from the 676,526 female participants in Cancer Prevention Study II (CPS-II). After twelve years of follow-up, 797 deaths from ovarian cancer were observed among women with no prior history of cancer or hysterectomy and 40 years of age or older in 1967 when ovulatory stimulants were approved in the United States. Cox proportional hazards modeling was used to compute rate ratios (RRs) and to adjust for other potential risk factors.Results: Overall, self-reported infertility was not significantly associated with ovarian cancer mortality (adjusted rate ratio (RR)=1.1, 95 percent confidence interval (CI)=0.9-1.3). Ovarian cancer death rates among nulligravid women with self-reported infertility, however, were 40 percent higher than for nulligravid women who never tried to become pregnant (RR=1.4, 95 percent CI=0.9-2.4). Multigravid women who reported infertility problems were not at increased risk.Conclusions: These results suggest that infertility itself, without concomitant exposure to fertility drugs, may increase risk of fatal ovarian cancer among nulligravid women.     

Physical activity and risk of ovarian cancer: a prospective cohort study in the United States.

Increased physical activity may lower the risk of ovarian cancer by reducing the frequency of ovulation, decreasing body fat, or diminishing chronic inflammation. Previous epidemiological studies examining the association between physical activity and risk of ovarian cancer have been inconsistent. We investigated the association of physical activity with ovarian cancer in a prospective cohort of 27,365 individuals from the Breast Cancer Detection Demonstration Project. During 227,045 person-years of follow-up, 121 cases of ovarian cancer were ascertained. Usual physical activity during the past year was assessed by a self-administered questionnaire. After adjusting for potential risk factors for ovarian cancer, the relative risks (95% confidence intervals) across increasing quintiles of total physical activity were 1.0, 0.73 (0.43-1.25), 0.84 (0.50-1.40), 0.56 (0.31-1.00), and 0.70 (0.41-1.21), respectively (P for trend = 0.13). In this prospective cohort study among U.S. women, we found no overall significant association between physical activity and risk of ovarian cancer, although the results are suggestive of an inverse association.     

Familial clustering of ovarian and endometrial cancers

Data on the association of ovarian cancer with other cancers in families are limited, and no data are available on the involvement of specific morphological types. The nationwide Swedish Family-Cancer Database on 10.2 million individuals and 19175 invasive ovarian cancers was used to calculate standardised incidence ratios (SIRs) and 95% confidence intervals (CIs) for familial ovarian cancer in 0-66-year-old daughters when mothers or sisters were affected. The SIR for concordant ovarian cancers was increased. When the mother or sister had breast cancer, the SIRs were 1.21 and 1.48, respectively; when they had endometrial cancer, the SIRs were 1.45 and 2.53. Multiple myeloma in the mother was associated with a risk of ovarian cancer in the daughter. The risk of endometrioid ovarian cancer was 3.40 in the daughter when the mother presented with endometrial cancer. Our data show a strong familial coupling of ovarian and endometrial cancers, which appears to be specific to the endometrioid morphology.     

Meat mutagens and risk of distal colon adenoma in a cohort of U.S. men.

Cooking meats at high temperatures and for long duration produces heterocyclic amines and other mutagens. These meat-derived mutagenic compounds have been hypothesized to increase risk of colorectal neoplasia, but prospective data are unavailable. We examined the association between intakes of the heterocyclic amines 2-amino-3,8-dimethylimidazo[4,5,-f]quinoxaline (MeIQx), 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), 2-amino-3,4,8-trimethylimidazo[4,5,-f]quinoxaline (DiMeIQx), and meat-derived mutagenicity (MDM) and risk of distal colon adenoma using a cooking method questionnaire administered in 1996 in the Health Professionals Follow-up Study cohort. Between 1996 and 2002, 581 distal colon adenoma cases were identified. Higher intake of MDM was marginally associated with increased risk of distal adenoma [fourth versus lowest quintile: odds ratio (OR), 1.39; 95% confidence interval (95% CI), 1.05-1.84; highest versus lowest quintile: OR, 1.29; 95% CI, 0.97-1.72; P(trend) = 0.08]. Adjusting for total red meat or processed meat intake did not explain those associations. Our data also suggested a positive association between higher MeIQx (highest versus lowest quintile: OR, 1.28; 95% CI, 0.95-1.71; P(trend) = 0.22) and risk of adenoma, but this association was attenuated after adjusting for processed meat intake. DiMeIQx and PhIP did not seem to be associated with risk of adenoma. In conclusion, higher consumption of mutagens from meats cooked at higher temperature and longer duration may be associated with higher risk of distal colon adenoma independent of overall meat intake. Because mutagens other than heterocyclic amines also contribute to MDM, our results suggest that mutagens other than heterocyclic amines in cooked meats may also play a role in increasing the risk of distal adenoma.     

Dietary acrylamide intake and the risk of endometrial or ovarian cancers in Japanese women

A meta‐analysis published in 2015 noted a marginally increased risk of endometrial and ovarian cancers in non‐smoking women with dietary acrylamide intake, but only a few studies were included, and they were limited to Western countries. The aim of this study was to investigate the association between dietary acrylamide intake and endometrial or ovarian cancer risk in the Japan Public Health Center‐based Prospective Study (JPHC Study). In this prospective cohort study, 47 185 participants aged 45‐74 years at the follow‐up starting point in the JPHC Study were enrolled. Dietary acrylamide intake was assessed using a validated food frequency questionnaire. Cox proportional hazards regression models were used to estimate hazard ratios (HR) and 95% confidence intervals (95%CI). In participants with endometrial and ovarian cancer, the average follow‐up periods were 15.5 and 15.6 years, respectively, and 161 and 122 cases of endometrial and ovarian cancer were diagnosed, respectively. Energy‐adjusted dietary acrylamide intake was negatively associated with endometrial cancer, but the association disappeared after adjusting for coffee consumption with an adjusted HR for the highest vs lowest tertile of 0.85 (95%CI: 0.54‐1.33). No association was observed, however, for ovarian cancer (adjusted HR, 0.77; 95%CI: 0.49‐1.23). Furthermore, after stratifying by smoking status, coffee consumption, alcohol consumption, body mass index, and menopause status, no association was observed. Dietary acrylamide intake was not associated with the risk of endometrial or ovarian cancer in Japanese women with a relatively lower dietary intake of acrylamide compared with Western populations.     

Serum uric acid and risk of cancer mortality in a large prospective male cohort

Objective To examine the prognostic role of serum uric acid (SUA) for cancer mortality in apparently healthy men across a wide age range. Methods Prospective data from a large cohort of 83,683 male Austrian adults with a median follow-up of 13.6 years was analyzed. Cox proportional hazards models, adjusted for established risk factors, were calculated to evaluate SUA as a predictive marker for fatal cancer events. Results High SUA (>6.71 mg/dl) was independently associated with increased risk of mortality from all cancers, showing a clear dose–response relationship (p for trend < 0.0001); the adjusted hazard ratio for the highest versus lowest quintile of SUA was 1.41 (1.22–1.62). In subgroup analyses this hazard ratio increased to 1.53 (1.29–1.80) for participants aged <65 years. When considering the time interval between baseline SUA measurement and subsequent death, SUA levels were more predictive for “late deaths”, occurring 10 or more years after screening (HR 1.65 [1.35–2.03], p < 0.0001), in comparison to deaths within 10 years after SUA measurement. In cancer site-specific analyses, SUA was significantly associated with deaths from malignant neoplasms of digestive organs (p = 0.03) and respiratory system and intrathoracic organs (p < 0.0001). Elevated SUA was further independently related to an increased risk of all-cause mortality (p < 0.0001). Conclusions Our results are contrary to the proposed antioxidant, inhibitory effect of SUA against cancer and rather suggest high SUA to be a valuable long-term surrogate parameter, indicative for a life-style at increased risk for the development of cancer.     

Endometriosis as a model for inflammation-hormone interactions in ovarian and breast cancers

Chronic inflammation has been implicated in a variety of cancers. In this review, we consider associations between endometriosis and cancers both local (ovarian) and distant (breast). We review the epidemiological data linking endometriosis to ovarian and breast cancers. We then consider evidence for a role for sex steroid hormones and for inflammation in the aetiology of each of these cancers. Finally, we consider that endometriosis may promote alterations in sex steroid hormones and inflammatory mediators. A possible explanation for the association between endometriosis and these reproductive cancers may then be local and systemic enhancement of aberrant inflammatory and hormonal mediators. If this hypothesis is true, endometriosis may need to be considered as a risk factor for ovarian and breast cancers, triggering increasingly intensive surveillance. Moreover, treatments for endometriosis may require consideration of the impact on long-term cancer risk.     

Aspirin and other nonsteroidal anti-inflammatory drugs and breast cancer incidence in a large U.S. cohort.

Use of nonsteroidal anti-inflammatory drugs (NSAIDs), particularly aspirin, has consistently been associated with reduced risk of breast cancer in case-control studies. However, results from prospective studies have been less consistent. We examined the association between NSAID use and breast cancer incidence, adjusting for multiple breast cancer risk factors among 77,413 women in the Cancer Prevention Study II Nutrition Cohort. During follow-up from 1992 to 2001, we observed 3,008 cases of incident breast cancer. Information on NSAID use was obtained from a questionnaire completed at enrollment in 1992 or 1993 and was updated using follow-up questionnaires in 1997 and 1999. NSAID use was modeled using time-dependent variables to update exposure status. Neither current total NSAID use (aspirin and other NSAIDs combined) nor current aspirin use were associated with breast cancer incidence even at relatively high levels of use [rate ratio (RR), 1.07; 95% confidence interval (95% CI), 0.96-1.21 for > or =60 NSAID pills per month compared with no reported use of NSAIDs; RR, 1.01; 95% CI, 0.84-1.20 for > or =60 aspirin per month compared with no reported use of aspirin]. Even long-duration regular use (> or =30 pills per month for > or =5 years) was not associated with breast cancer incidence (RR, 1.05; 95% CI, 0.88-1.26 for total NSAIDs; RR, 0.88; 95% CI, 0.69-1.12 for aspirin). Although we cannot exclude a small reduction in breast cancer risk associated with NSAID use, the results of this study provide evidence against a large reduction in risk.     

Physical activity and risk of endometrial cancer in a prospective cohort study (United States)

Objective: To examine the physical activity and endometrial cancer relationship in a prospective study of US women enrolled in the Breast Cancer Detection Demonstration Project (BCDDP) Follow-up Study. Methods: We assessed past-year physical activity of all types in 23,369 women who returned the baseline questionnaire (1987–1989) and had no prior hysterectomy and/or endometrial cancer. Cox proportional hazards models were used to estimate age, education, and parity-adjusted rate ratios (RR) and 95% confidence intervals (CI) for the 253 confirmed endometrial cancer cases identified during an average 8.2 years of follow-up (ending 1995–1998). Results: There were no dose–response relationships with either total or vigorous physical activity; however, compared to the lowest total activity quartile, the higher four quartiles had a non-significantly lower risk (RR = 0.8, CI = 0.6–1.0). The association with moderate activity varied with follow-up time: RRs (CI) for a 1 h increase in daily moderate activity within 2-year intervals of follow-up (2, 2.1–4.9, 5.0–8.0, >8 years) were 1.1 (1.0, 1.2), 1.0 (0.9, 1.1), 1.0 (0.9, 1.1), 1.0 (0.9, 1.1), and 0.8 (0.7, 1.0), respectively. Conclusion: These data suggest that recent physical activity is not strongly related to the risk of endometrial cancer, and that prolonged exposure and longer follow-up may be necessary.     

Cigarette smoking and the risk of invasive epithelial ovarian cancer in a prospective cohort study

Few cohort studies have examined the association between cigarette smoking and ovarian cancer risk, either overall, or by histological subtype. In relation to the latter, it has been suggested that mucinous ovarian tumours may be aetiologically unrelated to the other types of epithelial tumours and that their respective associations with cigarette smoking may differ. We examined the association between smoking and ovarian cancer risk using data from participants in a randomised controlled trial of screening for breast cancer involving 89,835 women aged 40-59 years at recruitment. Cox proportional hazards models were used to estimate rate ratios (RR) and 95% confidence intervals (CI). During an average of 16.5 years of follow-up, we observed 454 incident cases of ovarian cancer (184 serous, 67 endometrioid, 32 mucinous, 171 other or unknown). We found that women who had smoked for several decades had an approximately two-fold increased risk of epithelial ovarian cancer. Relative to never-smokers, women who had smoked for 40 years or more were at the highest risk (RR=2.50, 95% CI=1.37-4.56). The association with non-mucinous tumours was similar to that observed overall. For mucinous tumours, a two-fold increased risk was observed with smoking of shorter duration, although the number of mucinous tumours in our data-set was small. Long-term cigarette smoking may be associated with an increased risk of epithelial ovarian tumours.     

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.     

Smoking and quality of life among female survivors of breast, colorectal and endometrial cancers in a prospective cohort study

Purpose  

To examine the association of smoking and quality of life (QOL) among survivors of breast, colorectal, or endometrial cancers.