Obesity, physical activity and the risk of pancreatic cancer in a large Japanese cohort

It is unclear whether body mass index (BMI) and physical activity are associated with the risk of pancreatic cancer in Asian populations. We examined these associations in the Japanese Collaborative Cohort Study for Evaluation of Cancer Risk. Our cohort study included 110,792 Japanese men and women at enrollment (1988-1990). Data on height, body weight (at baseline and at age 20 years) and physical activity were obtained from a questionnaire. Cox proportional hazards models were used to estimate the relative risks of pancreatic cancer mortality. We observed a total of 402 pancreatic cancer deaths during the follow-up period. Men with a BMI of 30 or more at age 20 years had a 3.5-fold greater risk compared with men with a normal BMI. Women with a BMI of 27.5-29.9 at baseline had approximately 60% increased risk compared with women with a BMI of 20.0-22.4. In men, weight loss of 5 kg or more between 20 years of age and baseline age was associated with an increased risk of pancreatic cancer death. In contrast, women with weight loss of 5 kg or more over the same period had a decreased risk. Physical activity was not associated with pancreatic cancer risk in either men or women. Obesity in young adulthood may be associated with an increased risk of death from pancreatic cancer in Japanese men. The risk of pancreatic cancer in relation to BMI seems to differ according to sex and the period over which BMI was measured.     

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.     

Polymorphisms in DNA repair genes,recreational physical activity and breast cancer risk

The mechanisms driving the inverse association between recreational physical activity (RPA) and breast cancer risk are complex. While exercise is associated with increased reactive oxygen species production it may also improve damage repair systems, particularly those that operate on single‐strand breaks including base excision repair (BER), nucleotide excision repair (NER) and mismatch repair (MMR). Of these repair pathways, the role of MMR in breast carcinogenesis is least investigated. Polymorphisms in MMR or other DNA repair gene variants may modify the association between RPA and breast cancer incidence. We investigated the individual and joint effects of variants in three MMR pathway genes (MSH3, MLH1 and MSH2) on breast cancer occurrence using resources from the Long Island Breast Cancer Study Project. We additionally characterized interactions between RPA and genetic polymorphisms in MMR, BER and NER pathways. We found statistically significant multiplicative interactions (p < 0.05) between MSH2 and MLH1, as well as between postmenopausal RPA and four variants in DNA repair (XPC‐Ala499Val, XPF‐Arg415Gln, XPG‐Asp1104His and MLH1‐lle219Val). Significant risk reductions were observed among highly active women with the common genotype for XPC (OR = 0.54; 95% CI, 0.36–0.81) and XPF (OR = 0.62; 95% CI, 0.44–0.87), as well as among active women who carried at least one variant allele in XPG (OR = 0.46; 95% CI, 0.29–0.77) and MLH1 (OR = 0.46; 95% CI, 0.30–0.71). Our data show that women with minor alleles in both MSH2 and MLH1 could be at increased breast cancer risk. RPA may be modified by genes in the DNA repair pathway, and merit further investigation.     

Baseline recreational physical activity, history of sports participation, and postmenopausal breast carcinoma risk in the Netherlands Cohort Study.

BACKGROUND: The aim of the current study was to evaluate the relation between physical activity and breast carcinoma risk with specific emphasis on interaction with other aspects of energy balance. METHODS: The Netherlands Cohort Study on diet and cancer was conducted among 62,537 women ages 55-69 years at baseline. Information regarding baseline recreational physical activity, history of sports participation, and occupational physical activity was collected with a questionnaire in 1986. After 7.3 years of follow-up, 1208 incident breast carcinoma cases were available for case-cohort analyses. RESULTS: A summed total of baseline recreational physical activity (including walking, cycling, gardening) showed an inverse association with breast carcinoma risk. Women who were active in the above-mentioned activities for > 90 minutes a day had a rate ratio (RR) of 0.76 (95% confidence interval [95% CI], 0.58-0.99) compared with women who were active < 30 minutes a day. Women who ever participated into sports before baseline had a RR of 1.13 (95% CI, 0.94-1.37) compared with women who never participated in sports. The relation between sports participation and breast carcinoma risk did not appear to be dependent on the time window of participation (before/after menarche, before/after birth of the first child, before/after age 20 years). No interaction was found between baseline recreational physical activity, body mass index (BMI) (kg/m(2)), energy intake, and weight gain/loss during adult life in relation to breast carcinoma, although in the subgroup of women with a high BMI we found a stronger inverse relation between recreational physical activity and breast carcinoma risk independent of energy intake. Occupational physical activity was not found to be related to breast carcinoma risk. CONCLUSIONS: The current study findings support the hypothesis that recreational physical activity is associated inversely with breast carcinoma risk.     

Lifetime recreational and occupational physical activity and risk of in situ and invasive breast cancer.

Numerous studies have observed reduced breast cancer risk with increasing levels of physical activity, yet these findings have been inconsistent about optimal times of activity and effect modification by other factors. We investigated the association between recreational and occupational physical activity and breast cancer risk in a population-based case-control study in Massachusetts, New Hampshire, and Wisconsin. During structured telephone interviews, 7,630 controls, 1,689 in situ, and 6,391 invasive breast cancer cases, ages 20 to 69 years, reported lifetime history of recreational physical activity and occupation. Neither lifetime recreational nor strenuous occupational physical activity appeared to be associated with risk of breast carcinoma in situ. In contrast, recreational physical activity was associated with a reduced risk of invasive breast cancer. After adjustment for potentially confounding factors, women averaging >6 h per week of strenuous recreational activity over their lifetime had a 23% reduction in the odds ratio of invasive breast cancer when compared with women reporting no recreational activity (95% confidence interval, 0.65-0.92; P(trend) = 0.05). However, this reduction in risk was limited to women without a first-degree family history of breast cancer (P(interaction) = 0.02). Inverse associations were observed for physical activity early in life, in the postmenopausal years, and in the recent past, but these findings were confined to women without a family history of breast cancer. Lifetime strenuous occupational activity was not associated with invasive breast cancer risk. These results provide further evidence that, for most women, physical activity may reduce the risk of invasive breast cancer.     

Prospective study of recreational physical activity and ovarian cancer.

BACKGROUND: It has been hypothesized that physical activity may reduce the risk of ovarian cancer by decreasing estrogen levels, reducing body fat, and reducing the frequency of ovulation. Epidemiologic studies of this relationship have obtained inconsistent results. The only prospective study to date reported a positive association between frequent vigorous exercise and ovarian cancer risk. We further evaluated this relationship in the Nurses' Health Study cohort. METHODS: Participation in recreational physical activity was assessed by questionnaire in 1980, 1982, 1986, 1988, 1992, and 1994, with questions assessing exercise frequency, duration, and intensity. Results were adjusted for age, parity, oral contraceptive use, tubal ligation, and other risk factors for ovarian cancer. All statistical tests were two-sided. RESULTS: During a 16-year follow-up (from 1980 to 1996), 1.2 million person-years were accrued by 92 825 cohort members, and 377 cases of epithelial ovarian cancer were confirmed. The relative risk (RR) of ovarian cancer for women engaging in recreational physical activity for 7 hours or more per week compared with those reporting less than 1 hour per week was 0.80 (95% confidence interval [CI] = 0.49 to 1.32; P(trend) =.59). When both the frequency and intensity of activity were taken into account, activity level was also not associated with a reduced risk of ovarian cancer. Compared with inactive women, participants reporting high activity in terms of metabolic equivalent task hours (MET hours) were at greater risk of ovarian cancer (RR for 20 to <30 MET hours/week = 1.84 [95% CI = 1.12 to 3.02]; RR for >30 MET hours/week = 1.27 [95% CI = 0.75 to 2.14]). CONCLUSIONS: Overall, results did not suggest an inverse association between recreational physical activity and ovarian cancer. The possibility of a modest increase in risk with frequent vigorous activity requires further investigation.     

Body mass index and physical activity as risk factors for pancreatic cancer: the Multiethnic Cohort Study

Objective To examine body mass index (BMI) and physical activity as risk factors for pancreatic cancer. Methods Eight-year prospective data from 77,255 men and 90,175 women including 237 and 235 pancreatic cancer cases, respectively, in the Hawaii-Los Angeles Multiethnic Cohort Study were analyzed. Participants completed a questionnaire that included questions on body weight, height, and physical activity. Cox proportional hazards models were calculated to estimate relative risks (RR) of pancreatic cancer by levels of BMI and total physical activity (as metabolic equivalents (METs)) adjusted for several potential confounders. Results Obesity (BMI ≥ 30 kg/m²) was associated with an increased pancreatic cancer risk in men (RR = 1.51 (95% CI: 1.02–2.26)), but a reduced risk in women (RR = 0.65 (95% CI: 0.43–0.99)). In men the risk was higher in never smokers than in current or former smokers, though differences were not statistically significant. Physical activity was not associated with pancreatic cancer risk in either men or women. Conclusion The findings suggest, that a BMI of ≥ 30 kg/m² may be a risk factor for pancreatic cancer in men. No evidence of an effect of physical activity on risk was found.     

Obesity, high energy intake, lack of physical activity, and the risk of kidney cancer.

The authors conducted a population-based case-control study of 810 cases with histologically confirmed incident kidney cancer and 3,106 controls to assess the effect of obesity, energy intake, and recreational physical activity on renal cell and non-renal cell cancer risk in Canada from 1994 to 1997. Compared with normal body mass index (BMI; 18.5 to <25.0 kg/m2), obesity (BMI, >or=30.0 kg/m2) was associated with multivariable-adjusted odds ratios (OR) and 95% confidence intervals (95% CI) of 2.57 (2.02-3.28) for renal cell cancer and 2.79 (1.70-4.60) for non-renal cell cancer. The OR (95% CI) associated with the highest quartiles of calorie intake was 1.30 (1.02-1.66) for renal cell cancer and 1.53 (0.92-2.53) for non-renal cell cancer. Compared with the lowest quartile of total recreational physical activity, the highest quartile of total activity was associated with an OR (95% CI) of 1.00 (0.78-1.28) and 0.79 (0.46-1.36) for the two subtypes. There were no apparent differences between men and women about these associations. The influence of obesity and physical activity on the risk of renal cell and non-renal cell cancer did not change by age, whereas the effect of excess energy intake was stronger among older people. No significant effect modifications of physical activity on BMI among both genders and of energy intake on BMI among men were observed, with a synergic effect of obesity and high energy intake on renal cell cancer risk found among women. This study suggests that obesity and excess energy intake are important etiologic risk factors for renal cell and non-renal cell cancer. The role of physical activity needs further investigation.     

Timing and intensity of recreational physical activity and the risk of subsite-specific colorectal cancer

Purpose  

Although there is convincing evidence that physical activity reduces colon cancer risk, there are important questions that remain unanswered about the association. These include the timing and intensity of activity required to optimally reduce risk, and whether physical activity has a different effect on cancers at different sites within the colon. We conducted a case–control study to investigate these issues.     

Anthropometry, physical activity, and endometrial cancer risk: results from the Netherlands Cohort Study

Although obesity is an established risk factor for endometrial cancer, evidence linking risk to height, weight change since age 20, and physical activity is limited. In this case-cohort study, 62 573 women from The Netherlands Cohort Study on Diet and Cancer were followed up from 1986 to 1995, and 226 endometrial cancer case patients were identified. In Cox proportional hazards analyses, women 175 cm or taller had an increased risk of endometrial cancer compared with those less than 160 cm (rate ratio [RR] = 2.57, 95% confidence interval [CI] = 1.32 to 4.99). Compared with women with a body mass index (BMI; kg/m2) between 20 and 22.9, women with a BMI of 30 or greater had a higher risk (RR = 4.50, 95% CI = 2.62 to 7.72; P(trend)<.001). Moreover, BMI at age 20 and BMI gain since age 20 were positively associated with endometrial cancer risk (P(trend) = .02 and <.001, respectively). Women who spent 90 minutes per day or more doing nonoccupational physical activities had a lower risk (RR = 0.54, 95% CI = 0.34 to 0.85; P(trend) = .002) compared with those who spent less than 30 minutes per day. High BMI and low physical activity were strong and independent risk factors for endometrial cancer.     

Assessments of physical activity and cancer risk.

The assessment of physical activity is one of the most important methodological issues in research into physical activity and cancer risk. A sedentary Western lifestyle has been observed to influence biological mechanisms promoting development of certain types of cancer. At present the totality of evidence supports a protective effect against cancers of the colon and probably the breast, while further data concerning carcinoma of other cancers are required. Thus, physical activity represents a powerful public health measure for reducing cancer risk. Studies of the association between physical activity and cancer risk have used a great variety of methods, but have most often included work and/or leisure time activity. Questionnaires are the method most often used and various components of physical activity such as type, frequency, intensity and lifetime physical activity have been recorded. However, the measurements used when assessing physical activity have been hampered by lack of accuracy as regards validity and reliability, missing information on the various components of physical activity and sparse information of lifetime exposure, and often no repeat assessments in cohort studies. Discrepancies between studies elaborating the association between physical activity and site-specific cancer risk may be explained through real differences or lack of information on the various components of physical activity (type, intensity, duration) and incomplete information about the cancer type studied (localization, histological type). The complicated nature of the variable physical activity, combined with incomplete understanding of the pathogenesis of most cancer and lack of knowledge regarding possible biological mechanisms operating between physical activity and cancer, warrants further studies. In these studies methodological improvements in measuring physical activity, combined with inclusion of physiological markers (heart rate, energy balance, hormonal levels, etc.) reflecting the variety of physical activities performed are of particular interest. Assessing biomarkers and intermediate steps for site-specific cancer risk may give us further insight into the relation between physical activity and cancer that will be of enormous interest for public health recommendations.     

Lifetime recreational moderate-to-vigorous physical activity and ovarian cancer risk: A case–control study

Results of epidemiologic studies of physical activity and ovarian cancer risk are inconsistent. Few have attempted to measure physical activity over the lifetime or in specific age windows, which may better capture etiologically relevant exposures. We examined participation in moderate-to-vigorous recreational physical activity (MVPA) in relation to ovarian cancer risk. In a population-based case–control study conducted in Montreal, Canada from 2011 to 2016 (485 cases and 887 controls), information was collected on lifetime participation in various recreational physical activities, which was used to estimate MVPA for each participant. MVPA was represented as average energy expenditure over the lifetime and in specific age-periods in units of metabolic equivalents (METs)-hours per week. Odds ratios (OR) and 95% confidence intervals (CI) for the relation between average MVPA and ovarian cancer risk were estimated using multivariable logistic regression models. Confounding was assessed using directed acyclic graphs combined with a change-in-estimate approach. The adjusted OR (95% CI) for each 28.5 MET-hr/week increment of lifetime recreational MVPA was 1.11 (0.99–1.24) for ovarian cancer overall. ORs for individual age-periods were weaker. When examined by menopausal status, the OR (95% CI) for lifetime MVPA was 1.21 (1.00–1.45) for those diagnosed before menopause and 1.04 (0.89–1.21) for those diagnosed postmenopausally. The suggestive positive associations were stronger for invasive ovarian cancers and more specifically for high-grade serous carcinomas. These results do not support a reduced ovarian cancer risk associated with MVPA.     

Longitudinal study of recreational physical activity in breast cancer survivors

Introduction

Few longitudinal studies have examined physical activity (PA) levels in breast cancer survivors and how those levels change following cancer diagnosis and treatment.

Methods

We conducted a longitudinal cohort study of 315 female residents of Washington State, aged 21–74 years, diagnosed with a first primary invasive breast cancer between 2002 and 2004, and identified by a population-based cancer registry. Recreational PA was assessed for the 2-year period before diagnosis and at three intervals after diagnosis (1–12, 13–18, and 19–30 months). We calculated average metabolic equivalent task (MET) hours/wk of total, low-, moderate-, and vigorous-intensity PA.

Results

Mean PA levels decreased by 50% in the 12 months after diagnosis relative to before diagnosis (from 18.8 to 9.2 MET-hours/wk). At 19–30 months post-diagnosis, overall PA levels had increased from the low levels reported in the first year after diagnosis, but remained approximately 3 MET-hours/wk lower than before diagnosis. Reductions were limited to moderate- and vigorous-intensity activities. Declines in PA differed according to certain characteristics of the study population, with the greatest reductions observed in women <40 years at diagnosis and with a pre-diagnosis body mass index <25 kg/m²; these women were also more likely to report the greatest activity before diagnosis.

Conclusions

These results, if replicated in other studies, suggest that effective intervention strategies to increase PA in breast cancer survivors may differ according to patient characteristics.

Implications for cancer survivors

Younger, normal weight, and relatively active women may benefit most from interventions to minimize the decline in PA following diagnosis, while women who are older, overweight, and relatively inactive at diagnosis may benefit from interventions to increase long-term PA.     

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.     

Body mass index, physical activity, and bladder cancer in a large prospective study.

Increased body size and lack of physical activity are associated with increased risk of several cancers, but the relations of body mass index (BMI) and physical activity to bladder cancer are poorly understood. We investigated the associations between BMI, physical activity, and bladder cancer in the NIH-AARP Diet and Health Study, a prospective cohort of 471,760 U.S. men and women, followed from 1995 to 2003. During 3,404,642 person-years of follow-up, we documented 1,719 incident cases of bladder cancer. Compared with normal weight, obesity was associated with an up to 28% increased risk for bladder cancer. The multivariate relative risks of bladder cancer for BMI values of 18.5 to 24.9 (reference), 25.0 to 29.9, 30.0 to 34.9, and >or=35 kg/m2 were 1.0, 1.15, 1.22, and 1.28 (95% confidence interval, 1.02-1.61; P trend = 0.028). The association between BMI and bladder cancer was consistent among subgroups defined by gender, education, smoking status, and other potential effect modifiers. In contrast, physical activity showed no statistically significant relation with bladder cancer. After multivariate adjustment, including BMI, the relative risks of bladder cancer for increasing frequency of physical activity [0 (reference), <1, 1-2, 3-4, and >or=5 times a week] were 1.0, 0.85, 0.89, 0.91, and 0.87 (95% confidence interval, 0.74-1.02; P trend = 0.358), respectively. In conclusion, these findings provide support for a modest adverse effect of adiposity on risk for bladder cancer. In contrast, our results do not suggest a relation between physical activity and bladder cancer.     

Recreational physical activity and risk of postmenopausal breast cancer in a large cohort of US women

Due to its potential effects on ovarian hormone production, physical activity has been proposed as a modifiable risk factor for breast cancer. The authors analyzed data from the American Cancer Society Cancer Prevention Study II (CPS-II) Nutrition Cohort to examine the association between various measures of physical activity and postmenopausal breast cancer risk. Information on physical activity was obtained in 1992 via a self-administered questionnaire for 72,608 postmenopausal female participants who were cancer-free. During the five year prospective follow-up, 1520 incident breast cancer cases were identified among these women. Cox proportional hazards modeling was used to compute hazard rate ratios (RR) and to adjust for potential confounding factors including mammography. Women who were most physically active (>42.0 MET-h/week) at baseline had 29% lower incidence rates than active women with the least activity (>0–7.0 MET-h/week) (95% CI, 0.49–1.02). The difference in risk was largest for localized breast cancer, and for women who did not use hormone replacement therapy (HRT) at enrollment. Our findings are consistent with other studies that show lower risk of postmenopausal breast cancer associated with regular physical activity.     

Lifetime occupational and recreational physical activity and risk of benign prostatic hyperplasia

To investigate the relation between occupational and recreational physical activity (PA) in different periods of life and the risk of benign prostatic hyperplasia (BPH), we conducted a hospital-based, case-control study in Italy. The study included 1,369 histologically confirmed BPH and 1,451 controls, admitted to the same hospitals for acute, nonneoplastic diseases. Odds ratios (ORs) and 95% confidence intervals (CIs) of BPH, according to lifetime PA, were obtained by unconditional multiple logistic regression models, including terms for age, study center and education. Compared to the lowest level of occupational PA, the multivariate ORs for BPH for the heavy/strenuous level were 0.6 (95% CI, 0.4-0.8) at age 15-19, 0.6 (95% CI, 0.4-0.8) at age 30-39 and 0.7 (95% CI, 0.5-0.9) at age 50-59. Moreover, compared to <2 hr/week of recreational PA, the ORs for BPH for the highest level (>or=5 hr/week) were 0.5 (95% CI, 0.4-0.7) at age 15-19, 0.6 (95% CI, 0.5-0.8) at age 30-39, and 0.7 (95% CI, 0.5-0.8) at age 50-59. All inverse trends in risk were significant, and no heterogeneity was found by reason of BPH-diagnosis, age at diagnosis, and body mass index (BMI). The inverse association between PA and BPH risk may be due to favorable hormonal correlates of PA, but residual confounding by socioeconomic covariates cannot be excluded. A moderate PA at any ages may help reducing a sizeable number of BPH.     

Amount, type, and timing of recreational physical activity in relation to colon and rectal cancer in older adults: the Cancer Prevention Study II Nutrition Cohort.

Physical activity has consistently been associated with lower risk of colon cancer, but information is limited on the amount, type, and timing of activities. The relationship between physical activity and rectal cancer is unclear. We examined characteristics of recreational physical activity in relation to colon and rectal cancer in the Cancer Prevention Study II Nutrition Cohort of 70,403 men and 80,771 women (median age, 63 years); 940 colon and 390 rectal cancers were identified from enrollment in 1992 to 1993 through August 1999. The multivariate-adjusted rate ratios (95% confidence intervals) associated with any recreational physical activity compared with none were 0.87 (0.71-1.06) for colon cancer and 0.70 (0.53-0.93) for rectal cancer. Colon cancer risk decreased significantly with increasing total hours (P for trend without reference group = 0.007) and metabolic equivalent hours (P for trend = 0.006) per week of activities. No clear decrease in rectal cancer risk was seen with increasing hours per week of physical activity. Rate ratios (95% confidence intervals) were 0.72 (0.52-0.98) for <2 hours, 0.68 (0.47-0.97) for 2 to 3 hours, 0.59 (0.41-0.83) for 4 to 6 hours, and 0.83 (0.59-1.16) for >/=7 hours per week of physical activity compared with none. Past exercise, as reported in 1982, was not associated with risk of either colon or rectal cancer. We conclude that increasing amounts of time spent at recreational physical activity are associated with substantially lower risk of colon cancer and that recreational physical activity is associated with lower risk of rectal cancer in older men and women.     

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.