Karen Steindorf

Physical Activity and Risk of Colon and Rectal Cancers: The European Prospective Investigation into Cancer and Nutrition

We investigated several aspects of the role of physical activity in colon and rectal cancer etiology that remain unclear in the European Prospective Investigation into Nutrition and Cancer. This cohort of 413,044 men and women had 1,094 cases of colon and 599 cases of rectal cancer diagnosed during an average of 6.4 years of follow-up. We analyzed baseline data on occupational, household, and recreational activity to examine associations by type of activity, tumor subsite, body mass index (BMI), and energy intake. The multivariate hazard ratio for colon cancer was 0.78 [95% confidence interval (95% CI), 0.59-1.03] among the most active participants when compared with the inactive, with evidence of a dose-response effect (Ptrend = 0.04). For right-sided colon tumors, the risk was 0.65 (95% CI, 0.43-1.00) in the highest quartile of activity with evidence of a linear trend (Ptrend = 0.004). Active participants with a BMI under 25 had a risk of 0.63 (95% CI, 0.39-1.01) for colon cancer compared with the inactive. Finally, an interaction between BMI and activity (Pinteraction = 0.03) was observed for right-sided colon cancers; among moderately active and active participants with a BMI under 25, a risk of 0.38 (95% CI, 0.21-0.68) was found as compared with inactive participants with BMI >30. No comparable decreased risks were observed for rectal cancer for any type of physical activity for any subgroup analyses or interactions considered. We found that physical activity reduced colon cancer risk, specifically for right-sided tumors and for lean participants, but not rectal cancer. (Cancer Epidemiol Biomarkers Prev 2006;15(12):2398–407)

Anthropometric factors and risk of endometrial cancer: the European prospective investigation into cancer and nutrition

ObjectiveTo examine the association between anthropometry and endometrial cancer, particularly by menopausal status and exogenous hormone use subgroups.MethodsAmong 223,008 women in the European Prospective Investigation into Cancer and Nutrition (EPIC) study, there were 567 incident endometrial cancer cases during 6.4 years of follow-up. The analysis was performed with Cox proportional hazards modeling.ResultsWeight, body mass index (BMI), waist and hip circumferences and waist–hip ratio (WHR) were strongly associated with increased risk of endometrial cancer. The relative risk (RR) for obese (BMI 30– < 40 kg/m2) compared to normal weight (BMI < 25) women was 1.78, 95% CI = 1.41–2.26, and for morbidly obese women (BMI ≥ 40) was 3.02, 95% CI = 1.66–5.52. The RR for women with a waist circumference of ≥88 cm vs. <80 cm was 1.76, 95% CI = 1.42–2.19. Adult weight gain of ≥20 kg compared with stable weight (±3 kg) increased risk independent of body weight at age 20 (RR = 1.75, 95% CI = 1.11–2.77). These associations were generally stronger for postmenopausal than premenopausal women, and oral contraceptives never-users than ever-users, and much stronger among never-users of hormone replacement therapy compared to ever-users.ConclusionObesity, abdominal adiposity, and adult weight gain were strongly associated with endometrial cancer risk. These associations were particularly evident among never-users of hormone replacement therapy.

Impact of resistance training in cancer survivors: A meta-analysis

PURPOSE Current evidence suggests many health benefits from physical activity during and after cancer treatment. However, the optimal exercise program for cancer survivors has not yet been established. The purpose of this meta-analysis was to summarize evidence for the efficacy of resistance training (RT) interventions to improve muscle strength and body composition among adult cancer survivors. We also investigate potential dose-response relationships between intensity, duration, and frequency of RT and assessed outcomes. METHODS A systematic literature review of the Clinical Trial Register, Cochrane Trial Register, MEDLINE, and EMBASE literature databases was undertaken. Studies were included if they were randomized controlled trials (RCT) comparing RT with an exercise or nonexercise control group in cancer survivors during and after treatment. Thirteen articles from 11 RCT met our inclusion criteria. We performed a random-effects meta-analysis to determine weighted mean differences (WMD) with 95% confidence intervals using the Cochrane Review Manager 5.0.25. A random-effects metaregression model was performed to examine dose-response relationships between RT variables and assessed outcomes. RESULTS Quantitative evidence shows a large effect of RT on lower-limb and upper-limb muscle strength (WMD: +14.57 kg, P = 0.0005 and +6.90 kg, P < 0.00001, respectively) and moderate effects on lean body mass and percentage of body fat (WMD: +1.07 kg, P < 0.0001 and -2.08%, P = 0.003, respectively). A small positive effect of RT was noted on Functional Assessment of Cancer Therapy-Fatigue (P = 0.05). Upper-limb muscle strength and percentage of body fat improved to a greater extent when RT interventions were of low to moderate intensity (≤ 75% one-repetition maximum, P = 0.042). CONCLUSIONS RT was shown to be associated with clinically important positive effects on muscular function and body composition in patients during treatment or in long-term follow-up.

Cancer mortality in German male workers exposed to phenoxy herbicides and dioxins

In an occupational cohort study, the relation between exposure to phenoxy herbicides, and contaminants (dioxins and furans) and cancer mortality was investigated. A total of 2,479 workers from four plants in Germany were included, with a mortality follow-up until the end of 1989 (for one cohort, until the end of 1992). A total of 484 deaths were recorded yielding a standardized mortality ratio (SMR) of 101 (95 percent confidence interval [CI]=92–111) for total mortality, and an SMR of 119 (CI=100–141) for all malignant diseases. A variety of herbicides was produced, including those which are known to have been contaminated with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). High dioxin and furan exposure (in particular, exposure to TCDD, but also to higher chlorinated dioxins) had occurred in two of the four plants as shown by blood-fat measurements in a sample of workers. Mortality from all neoplasms increased with latency and was highest in the largest plant where the highest TCDD blood levels were recorded. An increased mortality in the total cohort from respiratory cancer (SMR=154, CI=115–202), cancer of the buccal cavity and pharynx (SMR=295, CI=135–560), and non-Hodgkins lymphoma (SMR=326, CI=119–710) was observed. Our findings are consistent with results from other cohorts which showed an increased overall cancer mortality and mortality of respiratory cancer after long-term exposure to these phenoxy herbicides and dioxins.

Physical activity and risk of endometrial cancer: the European prospective investigation into cancer and nutrition.

The etiologic role of physical activity in endometrial cancer risk remains unclear given the few epidemiologic studies that have been conducted. To investigate this relation more fully, an analysis was undertaken in the European prospective investigation into cancer and nutrition (EPIC). During an average 6.6 years of follow‐up, 689 incident endometrial cancer cases were identified from an analytic cohort within EPIC of 253,023 women. Cox proportional hazards models were used to estimate the associations between type of activity (total, occupational, household, recreational) and endometrial cancer risk. For total activity, women in the highest compared with the lowest quartile of activity had a risk of 0.88 (95% confidence interval (95% CI = 0.61–1.27). No clear associations between each type of activity and endometrial cancer risk were found for the total study population combined. Associations were more evident in the stratified results, with premenopausal women who were active versus inactive experiencing a risk of 0.66 (95% CI = 0.38–1.14) overall. Among premenopausal women, for household and recreational activities the risk estimates in the highest as compared with the lowest quartiles were, respectively, 0.48 (95% CI = 0.23–0.99) and 0.78 (95% CI = 0.44–1.39). No effect modification by body mass index, hormone replacement therapy, oral contraceptive use or energy intake was found. This study provides no evidence of a protective effect of increased physical activity in endometrial cancer risk in all women but some support for a benefit among premenopausal women. The relative risk reductions are most apparent for household activities.

Physical Activity and Postmenopausal Breast Cancer: Effect Modification by Breast Cancer Subtypes and Effective Periods in Life

Physical activity (PA) has been inversely associated with postmenopausal breast cancer risk. However, it is unclear how and in which life periods PA may be effective to reduce breast cancer risk. Moreover, the evidence is still not judged as ‘convincing’ as there is some heterogeneity among study results. Most studies regarded breast cancer as a single disease, at best separated by menopausal status. Yet, breast cancers are heterogeneous and likely have different etiologies. Therefore, we analyzed the association of PA with different breast cancer subtypes in 3,414 postmenopausal cases and 6,569 controls from a case-control study on breast cancer conducted 2002-2005 in Germany (MARIE study). PA in the age periods 30-49 and 50+ years was assessed, including leisure-time PA (sports, cycling, walking) and non-recreational PA (occupational and household activities). There was a significant protective effect of leisure-time PA for ER+/PR+ carcinomas (adjusted odds ratio = 0.71, 95% confidence interval: 0.60, 0.85; trend P = 0.0001), but no effect for ER-/PR- carcinomas. Moreover, looking at physical activity pattern over time, the effect of PA after menopause on reducing breast cancer risk was more pronounced than the effect of PA before menopause. Overall, effects of PA were independent from adult weight gain, body mass index, and energy intake. These findings suggest that leisure-time PA after menopause may reduce postmenopausal breast cancer risk at least in part via hormonal pathways and not solely by changing body composition. Inactive postmenopausal women should be encouraged to become physically active even later in life. (Cancer Epidemiol Biomarkers Prev 2008;17(12):3402–10)

Effects and moderators of exercise on quality of life and physical function in patients with cancer: An individual patient data meta-analysis of 34 RCTs

This individual patient data meta-analysis aimed to evaluate the effects of exercise on quality of life (QoL) and physical function (PF) in patients with cancer, and to identify moderator effects of demographic (age, sex, marital status, education), clinical (body mass index, cancer type, presence of metastasis), intervention-related (intervention timing, delivery mode and duration, and type of control group), and exercise-related (exercise frequency, intensity, type, time) characteristics. Relevant published and unpublished studies were identified in September 2012 via PubMed, EMBASE, PsycINFO, and CINAHL, reference checking and personal communications. Principle investigators of all 69 eligible trials were requested to share IPD from their study. IPD from 34 randomised controlled trials (n=4519 patients) that evaluated the effects of exercise compared to a usual care, wait-list or attention control group on QoL and PF in adult patients with cancer were retrieved and pooled. Linear mixed-effect models were used to evaluate the effects of the exercise on post-intervention outcome values (z-score) adjusting for baseline values. Moderator effects were studies by testing interactions. Exercise significantly improved QoL (β=0.15, 95%CI=0.10;0.20) and PF (β=0.18, 95%CI=0.13;0.23). The effects were not moderated by demographic, clinical or exercise characteristics. Effects on QoL (βdifference_in_effect=0.13, 95%CI=0.03;0.22) and PF (βdifference_in_effect=0.10, 95%CI=0.01;0.20) were significantly larger for supervised than unsupervised interventions. In conclusion, exercise, and particularly supervised exercise, effectively improves QoL and PF in patients with cancer with different demographic and clinical characteristics during and following treatment. Although effect sizes are small, there is consistent empirical evidence to support implementation of exercise as part of cancer care.

Randomized, controlled trial of resistance training in breast cancer patients receiving adjuvant radiotherapy: results on cancer-related fatigue and quality of life

BACKGROUND Exercise has been reported to decrease cancer-related fatigue and to increase quality of life (QoL) in various breast cancer (BC) populations. However, studies investigating exercise during radiotherapy or resistance training are scarce. We conducted a randomized, controlled trial (BEST study) to assess the efficacy of 12-week resistance training on fatigue beyond possible psychosocial effects of a group-based intervention. PATIENTS AND METHODS One hundred sixty patients with BC stage 0-III were randomly assigned to a 12-week progressive resistance training (2 times/week) or a 12-week relaxation control (RC, 2 times/week). Both interventions were group-based. The primary end point fatigue was assessed with a 20-item multidimensional questionnaire, QoL with EORTC questionnaires. Statistical analyses were based on analysis of covariance models for the individual changes from baseline to week 13. RESULTS Adherence to the intervention program as well as the completion rate (97%) for the primary outcome variable fatigue was high. In intention-to-treat analyses for the N = 155 patients, significant between-group mean differences (MD) favoring the exercise group (EX) were observed for general fatigue (P = 0.044), especially for the subscale physical fatigue [MD = -0.8; 95% confidence interval -1.5 to -0.2, P = 0.013], but not for affective (P = 0.91) or cognitive fatigue (P = 0.65). For QoL, significantly larger improvements regarding the role function (P = 0.035) and pain (P = 0.040) were noted among exercisers compared with RCs. Future perspective improved significantly stronger in the RC group compared with the EX group (P = 0.047). CONCLUSIONS The 12-week resistance training program was a safe, feasible and efficacious strategy to improve cancer-related fatigue and components of QoL in BC patients during adjuvant radiotherapy. As exercise was compared with another group-based intervention, results indicate that resistance training effects on fatigue and QoL go beyond psychosocial benefits, and that the clinically relevant overall benefit of resistance exercise compared with usual care can be assumed to be higher. TRIAL REGISTRATION ClinicalTrials.gov NCT01468766.

Physical activity and risk of breast cancer overall and by hormone receptor status: the European prospective investigation into cancer and nutrition.

Physical activity is associated with reduced risks of invasive breast cancer. However, whether this holds true for breast cancer subtypes defined by the estrogen receptor (ER) and the progesterone receptor (PR) status is controversial. The study included 257,805 women from the multinational EPIC‐cohort study with detailed information on occupational, recreational and household physical activity and important cofactors assessed at baseline. During 11.6 years of median follow‐up, 8,034 incident invasive breast cancer cases were identified. Data on ER, PR and combined ER/PR expression were available for 6,007 (67.6%), 4,814 (54.2%) and 4,798 (53.9%) cases, respectively. Adjusted hazard ratios (HR) were estimated by proportional hazards models. Breast cancer risk was inversely associated with moderate and high levels of total physical activity (HR = 0.92, 95% confidence interval (CI): 0.86–0.99, HR = 0.87, 95%‐CI: 0.79–0.97, respectively; p‐trend = 0.002), compared to the lowest quartile. Among women diagnosed with breast cancer after age 50, the largest risk reduction was found with highest activity (HR = 0.86, 95%‐CI: 0.77–0.97), whereas for cancers diagnosed before age 50 strongest associations were found for moderate total physical activity (HR = 0.78, 95%‐CI: 0.64–0.94). Analyses by hormone receptor status suggested differential associations for total physical activity (p‐heterogeneity = 0.04), with a somewhat stronger inverse relationship for ER+/PR+ breast tumors, primarily driven by PR+ tumors (p‐heterogeneity < 0.01). Household physical activity was inversely associated with ER–/PR– tumors. The results of this largest prospective study on the protective effects of physical activity indicate that moderate and high physical activity are associated with modest decreased breast cancer risk. Heterogeneities by receptor status indicate hormone‐related mechanisms.

Physical activity and lung cancer risk in the European Prospective Investigation into Cancer and Nutrition Cohort

Research conducted predominantly in male populations on physical activity and lung cancer has yielded inconsistent results. We examined this relationship among 416,277 men and women from the European Prospective Investigation into Cancer and Nutrition (EPIC). Detailed information on recent recreational, household and occupational physical activity, smoking habits and diet was assessed at baseline between 1992 and 2000. Relative risks (RR) were estimated using Cox regression. During 6.3 years of follow‐up we identified 607 men and 476 women with incident lung cancer. We did not observe an inverse association between recent occupational, recreational or household physical activity and lung cancer risk in either males or females. However, we found some reduction in lung cancer risk associated with sports in males (adjusted RR = 0.71; 95% confidence interval 0.50–0.98; highest tertile vs. inactive group), cycling (RR = 0.73; 0.54–0.99) in females and non‐occupational vigorous physical activity. For occupational physical activity, lung cancer risk was increased for unemployed men (adjusted RR = 1.57; 1.20–2.05) and men with standing occupations (RR = 1.35; 1.02–1.79) compared with sitting professions. There was no evidence of heterogeneity of physical activity associations across countries, or across any of the considered cofactors. For some histologic subtypes suggestive sex‐specific reductions, limited by subgroup sizes, were observed, especially with vigorous physical activity. In total, our study shows no consistent protective associations of physical activity with lung cancer risk. It can be assumed that the elevated risks found for occupational physical activity are not produced mechanistically by physical activity itself but rather reflect exposure to occupation‐related lung cancer risk factors.