Effects of physical activity on cancer prevention

Global scientific trends in research of epigenetic response to exercise: A bibliometric analysis

The purpose of this work is to comprehensively understand the adaptive response of multiple epigenetic modifications on gene expression changes driven by exercise. Here, we retrieved literatures from publications in the PubMed and Web of Science Core Collection databases up to and including October 15, 2023. After screening with the exclusion criteria, 1910 publications were selected in total, comprising 1399 articles and 511 reviews. Specifically, a total of 512, 224, and 772 publications is involved in DNA methylation, histone modification, and noncoding RNAs, respectively. The correlations between publication number, authors, institutions, countries, references, and the characteristics of hotspots were explored by CiteSpace. Here, the USA (621 publications) ranked the world's most-influential countries, the University of California System (68 publications) was the most productive, and Tiago Fernandes (14 publications) had the most-published publications. A comprehensive keyword analysis revealed that cardiovascular disease, cancer, skeletal muscle development, and metabolic syndrome, and are the research hotspots. The detailed impact of exercise was further discussed in different aspects of these three categories of epigenetic modifications. Detailed analysis of epigenetic modifications in response to exercise, including DNA methylation, histone modification, and changes in noncoding RNAs, will offer valuable information to help researchers understand hotspots and emerging trends.

Oxidative balance score and risk of cancer: a systematic review and meta-analysis of observational studies

BACKGROUND

The oxidative balance score (OBS) has been utilized to assess the overall pro- and antioxidant exposure status in various chronic diseases. The current meta-analysis was carried out to pool the association between OBS and the risk of cancer.

METHODS

We systematically searched the Web of Science, PubMed, Scopus, Embase, and Google Scholar up to August 2023. All observational studies which evaluated the association of OBS with the risk of cancers were included. There was no time of publication or language restrictions. Heterogeneity between studies was assessed using the Chi-square-based Q-test and the I2. A random-effects model meta-analysis was conducted to estimate the pooled effect sizes. Possible sources of heterogeneity were explored by subgroup and meta-regression analysis.

RESULTS

Totally, 15 studies (9 case-control and 6 cohorts) were eligible for meta-analysis. Random effect model meta-analysis of case-control studies showed that higher OBS significantly decreases the odds of cancers (pooled OR: 0.64, 95% CI: 0.54, 0.74). In the cohort studies, the association of OBS with the risk of cancers was not significant (pooled HR: 0.97, 95% CI: 0.80,1.18). The subgroup analysis showed that cancer type and gender were the potential sources of heterogeneity.

CONCLUSION

Our results show an inverse and significant association between higher OBS and odds of colorectal cancers in case-control and cohort studies. In the case of prostate cancer in cohort studies, our results did not align with the hypothesis. Considering the importance of diet and antioxidant balance in the conditions of malignancy, it is suggested to conduct more comprehensive studies with standard measurement methods to obtain conclusive results.

Exploring University and Healthcare Workers' Physical Activity, Diet, and Well-Being During the COVID-19 Pandemic

BACKGROUND

The COVID-19 pandemic affected well-being and health behaviors, especially among healthcare workers and employees in other fields. This is of public health concern because health behaviors and well-being influence long-term negative health outcomes. The purpose of this study was to explore health behaviors and well-being among university and medical center staff during COVID-19.

METHODS

EMPOWER (Employee Well-being during Epidemic Response) was a three-wave observational study (wave 1: 1,994; wave 2: 1,426; wave 3: 1,363) measuring health behaviors and well-being of university and medical center staff. Surveys were disseminated online to all employees between April and September 2020. Descriptive statistics explored trends across waves for health behaviors (physical activity [PA], diet), and well-being (mental well-being [MWB], depression, anxiety, and stress). Logistic regressions explored associations between health behaviors and well-being factors adjusting for demographics and clinical role. Interactions explored moderation by clinical role.

RESULTS

Most participants reported same/healthier changes in PA (54-65%) and diet (57-73%) and decreased MWB across waves (62%-69%). Nonclinical workers were less likely than clinical workers to experience worse MWB and moderate/severe anxiety and stress (odds ratios [ORs] ranged from 0.38 to 0.58 across waves and well-being outcomes). Participants who maintained/increased PA and diet were less likely to experience worse well-being (ORs ranged from 0.44 to 0.69 across waves and well-being outcomes). Interactions by clinical role were not significant.

CONCLUSION/APPLICATION TO PRACTICE

Maintaining/increasing health behaviors during COVID-19 may be protective of mental health/well-being in some healthcare workers. These findings support health promotion efforts focused on maintaining or improving diet and PA.

Physical Activity Delays Obesity-Associated Pancreatic Ductal Adenocarcinoma in Mice and Decreases Inflammation

BACKGROUND & AIMS

Obesity is a risk factor for pancreatic ductal adenocarcinoma (PDAC), a deadly disease with limited preventive strategies. Lifestyle interventions to decrease obesity might prevent obesity-associated PDAC. Here, we examined whether decreasing obesity by increased physical activity (PA) and/or dietary changes would decrease inflammation in humans and prevent PDAC in mice.

METHODS

Circulating inflammatory-associated cytokines of overweight and obese subjects before and after a PA intervention were compared. PDAC pre-clinical models were exposed to PA and/or dietary interventions after obesity-associated cancer initiation. Body composition, tumor progression, growth, fibrosis, inflammation, and transcriptomic changes in the adipose tissue were evaluated.

RESULTS

PA decreased the levels of systemic inflammatory cytokines in overweight and obese subjects. PDAC mice on a diet-induced obesity (DIO) and PA intervention, had delayed weight gain, decreased systemic inflammation, lower grade pancreatic intraepithelial neoplasia lesions, reduced PDAC incidence, and increased anti-inflammatory signals in the adipose tissue compared to controls. PA had additional cancer prevention benefits when combined with a non-obesogenic diet after DIO. However, weight loss through PA alone or combined with a dietary intervention did not prevent tumor growth in an orthotopic PDAC model. Adipose-specific targeting of interleukin (IL)-15, an anti-inflammatory cytokine induced by PA in the adipose tissue, slowed PDAC growth.

CONCLUSIONS

PA alone or combined with diet-induced weight loss delayed the progression of PDAC and reduced systemic and adipose inflammatory signals. Therefore, obesity management via dietary interventions and/or PA, or modulating weight loss related pathways could prevent obesity-associated PDAC in high-risk obese individuals.

Esophageal Carcinoma and Associated Risk Factors: A Case-control Study in Two Tertiary Care Hospitals of Kabul, Afghanistan

Purpose

Esophageal cancer (EC) is the most common cancer among males in Afghanistan, thus we aimed to conduct a case-control study to determine the associated risk factors with EC in two tertiary care hospitals of Kabul, Afghanistan.

Patients and Methods

We enrolled 132 EC cases and 132 controls and used conditional logistic regression to estimate the odds ratio (OR) with consideration of 95% confidence interval (CI).

Results

The results of our study revealed that esophageal squamous cell carcinoma (ESCC) was the predominant type of EC constituting 75.8% of the cases. The results of the multivariate logistic analysis showed that males and older ages were at increased risk of developing EC (OR: 4.62, 95%CI, p-value=0.026) and (OR: 1.070, 95%CI, p-value <0.001), respectively. In addition, living in rural areas (OR: 46.64, 95%CI, p-value <0.001), being uneducated (OR: 13.94, 95%CI, p-value=0.042), using oral snuff (OR: 6.10, 95%CI, p-value=0.029), drinking hot tea (OR: 5.719, 95%CI, p-value=0.005), lack of physical exercise (OR: 32.548, 95%CI, p-value=0.001), less fresh fruit consumption (OR: 93.18, 95%CI, p-value<0.001) and family history of cancer (OR: 14.50, 95%CI, p-value=0.003) were significantly associated with the development of EC, while body mass index (BMI), smoking, alcohol drinking, consumption of spicy food and pickled vegetables did not have a significant association with EC. Moreover, the majority of the cases (83.3%) in our study were from to low-income families and the majority were unemployed (93.9%), of whom (50%) were farmers, who did not show statistically significant association.

Conclusion

Our study concluded that EC risk was higher in older ages, males, rural residents, uneducated people, oral-snuff users, hot tea drinkers, fewer fresh fruit consumers, lack of physical exercise, and family history of cancer. Further detailed studies and screening policies of the affected groups are suggested to further elaborate on the subject.

Origanum majorana L. Extract Attenuated Benign Prostatic Hyperplasia in Rat Model: Effect on Oxidative Stress, Apoptosis, and Proliferation

Benign prostatic hyperplasia (BPH) is a widespread androgenic illness influencing elderly men. It is distinguished by prostatic epithelial and stromal muscle cell proliferation. Inflammation, oxidative stress, and apoptosis have all been interrelated to the development of BPH. Marjoram (Origanum majorana L.) is a herb with reported antiproliferative, proapoptotic, and antioxidative properties, which have not yet been studied in relation to BPH. Consequently, in this work, an ethanolic extract of O. majorana was prepared in two doses (250 and 500 mg/kg/day) to be injected into castrated rats after induction of a testosterone-BPH model. Testosterone propionate (TP) was subcutaneously injected (0.5 mg/kg/day) for one week after castration to induce BPH. Forty adult Wistar male rats were randomly allocated into five groups: control, BPH model, high and low O. majorana doses (250, 500 mg/kg/day), and finasteride (FN) (0.8 mg/kg/day) as a positive control. Treatment was continued with drugs/normal saline for 28 days. Rat’s body and prostate were weighed, prostate index (PI) and % of prostate growth inhibition were calculated, serum dihydrotestosterone (DHT), prostatic content of superoxide dismutase (SOD), catalase (CAT), total antioxidant capacity (TAC), and malondialdehyde (MDA), DN damage, histopathological changes, immune expression of proliferating cell nuclear antigen (PCNA), caspase-3, α-SMA, and TGF-β1 were assessed. In addition, molecular quantitative PCR and ELISA analyses were performed to identify the expression of mRNAs and related proteins of both caspase-3 and TGF-β1 in prostate tissue from O. majorana-treated and untreated groups. Rats with BPH had significantly higher prostate weights and PI, higher DHT, DNA damage (8-hydroxyguanine, 8-OH-dG), and MDA levels with prominent PCNA, α-SMA, and TGF-β expression, but lower SOD, CAT, and TAC activity and caspase-3 expression. O. majorana (250 and 500 mg/kg/day)-treated groups revealed a decrease in prostate weights and PI, lower levels of DHT, suppressed oxidative stress, reduced tissue proliferation and fibrosis, and restored antioxidant and proapoptotic activity. Additionally, quantitative PCR and ELISA analysis showed that treatment with O. majorana significantly upregulated the expression of caspase-3 and downregulated the expression of TGF-β in prostate tissues of BPH rats. The data were confirmed by the immunohistological reactivity of these targeted markers in the prostate tissues. These effects were more significant with O. majorana 500 mg/mL/rat. In conclusion, the current study indicates the efficient use of O. majorana in the treatment of testosterone-induced BPH through its antiproliferative, proapoptotic, and antioxidative mechanisms.

Studying the effect of garlic consumption and endurance training on serum levels of some pro-and anti-inflammatory cytokines in female mice with breast cancer - A randomized trial

Background:

This study aimed to determine the effect of garlic consumption and endurance training on the serum levels of some pro-inflammatory and anti-inflammatory cytokines in female mice with breast cancer.

Methods:

This study is an experimental research randomly conducted on 32 female BALB/c mice divided into 4 equal groups (N = 8), including: Cancer Control (CC), Garlic Supplementation (GS), Endurance Training (ET), Endurance Training + Garlic Supplementation (ET + GS). One million cancerous cells were injected to all mice's upper right thigh using the subcutaneous injection method. Exercise groups performed endurance training for 8 weeks (5 days a week.(Garlic supplement groups received 1 ml of the garlic extract orally per kilogram of body weight. The control groups -were not given any task, activity or exercise during the research. At the end of the research, all the mice were anesthetized, and their blood samples were collected.

Results:

The period of 8-week simultaneous endurance exercise and consumption of garlic supplement significantly decreased the serum level of interleukin-6 (F = 75 P = 0.00), interleukin-8 (F = 97.9 P = 0.00), and interleukin-17 (F = 95.7 P = 0.00), and increased the serum level of interleukin-10 (F = 50.4 P = 0.00).

Conclusions:

Along with other existing methods, reduction of inflammatory factors, endurance exercises and consumption of garlic supplement have been proved to be an extremely effective treatment for breast cancer patients.

Gene expression of angiogenesis and apoptotic factors in female BALB/c mice with breast cancer after eight weeks of aerobic training

OBJECTIVES

Breast cancer is the most common cancer in women, caused by a disorder in the angiogenesis and apoptosis process. Exercise can affect the process of angiogenesis and apoptosis in the tumor tissue. Thus, the aim of the present study was to investigate the changes in angiogenesis and apoptotic factors in mice with breast cancer after 8 weeks of exercise training.

MATERIALS AND METHODS

Sixteen females BALB/c mice (age: 3-5 weeks and weight: 17.1 ± 0.1 g) with breast cancer were randomly divided into two groups of aerobic training and control. The aerobic training included 8 weeks and 5 sessions per week of running with an intensity of 14-20 m.min-1. HIF-1α, VEGF, miR-21 and cytochrome C, Apaf-1, caspase-9, and caspase-3 gene expressions were examined by real-time PCR. Repeated measures ANOVA, Bonferroni's post hoc test, and independent samples t-test were used to analyze the data (P<0.05).

RESULTS

The results showed that aerobic training reduced the growth of tumor volume and significantly reduced miR-21 gene expression. Aerobic training also significantly increased the gene expression of HIF-1α, cytochrome C, Apaf-1, caspase-9, and caspase-3, while changes in VEGF gene expression were not statistically significant.

CONCLUSION

It appears that aerobic exercise training reduces tumor size and ameliorates breast cancer by reducing miR-21 gene expression, suppressing the apoptosis process, and reducing angiogenesis.

Physical exercise increases global and gene-specific (interleukin-17 and interferon-γ) DNA methylation in lymphocytes from aged women

NEW FINDINGS

What is the central question of this study? Is lymphocyte DNA methylation differentially modulated by resistance training and aerobic exercise in older women? What is the main finding and its importance? The practice of resistance training led to an increased global DNA methylation in lymphocytes. The exercise-induced increase of inflammatory genes methylation may be associated with immune function impairment during ageing.

ABSTRACT

Ageing-induced increase in inflammatory gene expression through a reduction in DNA methylation might contribute to chronic diseases. Regular physical exercise practices, in turn, are associated with a decrease in the incidence of inflammatory diseases. We herein evaluated the effects of three exercise modalities on lymphocyte global and gene-specific (interferon γ (IFN-γ) and interleukin 17A (IL-17A) DNA methylation in aged women (68 ± 7.5 years). This cross-sectional study included 86 women, divided into four groups according to the physical exercise practice: 20 were practicing resistance training (RT); 24 were practicing water aerobics exercise (W); 22 were practicing water aerobics and resistance exercise (RWT), and 20 did not practice any physical exercise (CON). We evaluated volunteer functional capability using the Timed Up and Go (TUG) test, global lymphocyte DNA methylation by enzyme-linked immunosorbent assay, IFN-γ and IL-17A methylation by qPCR and CD4⁺ IFN-γ⁺ and CD4⁺ IL-17⁺ cell percentage by flow cytometry. The three physically exercised groups performed functional capability tests in a shorter period and showed a higher global lymphocyte DNA methylation and methylated CpGs of IL-17A and IFN-γ promoter regions than the control group. The practice of resistance training (RT and RWT groups) lead to high global DNA methylation. The combination of resistance training and aerobic exercise led to the increase of lymphocyte IL-17A and IFN-γ gene methylation induced by each separately. However, the percentage of IFN-γ⁺ and IL-17⁺ cells was lower only in the RT group. The exercise-induced increase of inflammatory-gene methylation may be associated with gene expression changes and immune function impairment during ageing.

Interactive effect of TLR SNPs and exposure to sexually transmitted infections on prostate cancer risk in Jamaican men

BACKGROUND

Prostate cancer (PC) risk increases with African ancestry and a history of sexually transmitted infections (STIs). Also, single-nucleotide polymorphisms (SNPs) in toll-like receptor (TLR) genes influence PC risk. This pilot study explores interactions between STIs and TLR-related SNPs in relation to PC risk among Jamaican men.

METHODS

This case-control study evaluates two TLR related SNPs in 356 Jamaican men (194 controls and 162 cases) with or without history of STIs using stepwise penalized logistic regression in multivariable analyses.

RESULTS

Age (odds ratio [OR] = 1.08; 95% confidence interval [CI]: 1.04-1>.12; p < .001) and IRF3_rs2304206 GG genotype (OR = 0.47; 95% CI: 0.29-0<.78; p = .003) modulated PC risk in people with history of STIs. In the population with no history of STIs, resulting interactions between risk factors did not survive correction for multiple hypothesis testing.

CONCLUSION

Overall, an interaction between the IFR3_rs2304206 variant and a history of exposure to STIs leads to greater decrease of PC risk than the presence of polymorphic genotype alone. These findings are suggestive and require further validation. Identification of gene variants along with detection of lifestyle behaviors may contribute to identification of men at a greater risk of PC development in the population.

Effects of Physical Exercise on the Expression of MicroRNAs: A Systematic Review

Silva, FCd, Iop, RdR, Andrade, A, Costa, VP, Gutierres Filho, PJB, and Silva, Rd. Effects of physical exercise on the expression of microRNAs: A systematic review 34(1): 270-280, 2020-Studies have detected changes in the expression of miRNAs after physical exercise, which brings new insight into the molecular control of adaptation to exercise. Therefore, the objective of the current systematic review of experimental and quasiexperimental studies published in the past 10 years was to assess evidence related to acute effects, chronic effects, and both acute and chronic effects of physical exercise on miRNA expression in humans, as well as its functions, evaluated in serum, plasma, whole blood, saliva, or muscle biopsy. For this purpose, the following electronic databases were selected: MEDLINE by Pubmed, SCOPUS, Web of Science, and also a manual search in references of the selected articles to April 2017. Experimental and quasiexperimental studies were included. Results indicate that, of the 345 studies retrieved, 40 studies met the inclusion criteria and two articles were included as a result of the manual search. The 42 studies were analyzed, and it can be observed acute and chronic effects of physical exercises (aerobic and resistance) on the expression of several miRNAs in healthy subjects, athletes, young, elderly and in patients with congestive heart failure, chronic kidney disease, diabetes mellitus type 2 associated with morbid obesity, prediabetic, and patients with intermittent claudication. It is safe to assume that miRNA changes, both in muscle tissues and bodily fluids, are presumably associated with the benefits induced by acute and chronic physical exercise. Thus, a better understanding of changes in miRNAs as a response to physical exercise might contribute to the development of miRNAs as therapeutic targets for the improvement of exercise capacity in individuals with any given disease. However, additional studies are necessary to draw accurate conclusions.

The modulatory effects of exercise on the inflammatory and apoptotic markers in rats with 1,2-dimethylhydrazine-induced colorectal cancer

This study aimed to investigate the underlying mechanisms in anti-tumorigenesis effects of exercise through evaluation of inflammation and apoptosis. Twenty-four Wistar rats were divided into control, exercise, 1,2-dimethylhydrazine (DMH), and DMH + exercise. After a week, rats in the DMH group were given DMH twice a week for 2 weeks. Animals in the exercise groups performed exercise on a treadmill 5 days/week for 8 weeks. After 8 weeks of training, levels of COX-2, PCNA, Bax, Bcl-2, and procaspase-3/cleaved caspase-3 were assessed. Histological changes, number of aberrant crypt foci (ACF), and serum levels of TNF-α and IL-6 were also analyzed. ACF number was significantly decreased following the exercise program. Protein levels of COX-2 and PCNA and serum levels of IL-6 and TNF-α were significantly elevated in the rats receiving DMH and downregulated after performing the exercise program (P < 0.05). Exercise upregulated apoptosis, which was evident from the increased Bax/Bcl2 ratio, and enhanced the expression levels of activated caspase-3 as compared to the DMH group. The colonic architecture was improved in DMH + exercise. Exercise can effectively attenuate DMH-induced increase of inflammatory markers. Exercise induces apoptosis at the downstream of the inflammatory response. Therefore, exercise may play a role as a moderator of inflammation to exert protective effects against colon cancer.

A Qualitative Study Identifying Barriers and Facilitators of Physical Activity in Rural Communities

Background

Physical activity (PA) rates are lower in rural populations, compared to urban and suburban counterparts. Since PA is shown to decrease the risk of cancers and chronic diseases, increasing PA in rural environments is an important disease-prevention strategy. However, in order to develop effective interventions for rural populations, more research is needed. The purpose of the study was to elicit rural residents' thoughts and perceptions related to PA and walking trail use.

Methods

Key informant interviews were conducted via telephone, with 62 adults, living in six rural communities in southeast Missouri, who identified as stakeholders, walking trail users, and nontrail users. Participants were recruited through word of mouth and snowball sampling. Interviews were digitally audio-recorded, transcribed, and qualitatively analyzed.

Findings

Analysis revealed variation within the rural population, with each town unique in what constituted barriers and facilitators to PA. Life priorities other than physical health were found to be important motivators to PA and also influenced how PA was obtained. Community size was found to impact community resources and infrastructure, although this was mitigated by poverty rates.

Conclusion

Rural communities are distinct from one another with different views and approaches to PA. Future interventions designed to increase PA should be mindful of differences at the individual and town levels and avoid a one-size-fits-all approach. Interventions would benefit from insight and support from community members and stakeholders, to facilitate a tailored approach to increase PA.

Effect of exercise on colorectal cancer prevention and treatment

In recent years, because of improved cancer screening, detection and treatment modalities, a rapid increase in the population of colorectal and other cancer survivors has been observed. The increasing population has justified the requirement of preventive strategies such as lifestyle modifications with regard to obesity, physical activity, diet and smoking. Physical activity may prevent approximately 15% of the colon cancers. Furthermore, several observational studies have demonstrated the efficacy and dose-dependent and anti-cancer effects of exercise on decreasing the mortality and risk of recurrence before and after the colorectal cancer (CRC) diagnosis. However, the required exercise dose, type and intensity are yet unclear. The results of randomised prospective studies are expected to determine the optimal amount, type and intensity of exercise and formulate the most appropriate exercise plan and guidelines, according to the requirements and comorbidities of the patients. In addition, recent studies have focused on the molecular and genetic mechanisms underlying the effect of physical activity on disease outcomes and recurrence rates. This review aimed to investigate the effects of physical activity and the biological basis of these effects in preventing the risk and recurrence of CRC and decreasing the hazards of cancer and cancer treatment.

Leisure-time physical activity and DNA damage among Japanese workers

BACKGROUND

It remains unclear whether daily physical activity is associated with DNA damage. This cross-sectional study examined the association between leisure-time physical activity and urinary 8-hydroxydeoxyguanosine (8-OH-dG), a biomarker of oxidative DNA damage, or urinary 7-methylguanine (m7Gua), a biomarker of methylating DNA damage.

METHODS

Participants included 501 workers (294 men and 207 women), aged 20-65 years, from municipal offices in Japan. Urinary 8-OH-dG and m7Gua were measured using column-switching HPLC. Physical activity was evaluated using a self-reported questionnaire. The associations between leisure-time physical activity and urinary DNA damage markers were assessed by multiple linear regression analysis, with stratification by occupational physical activity.

RESULTS

After adjusting for covariates, leisure-time physical activity showed a suggestive inverse correlation with urinary 8-OH-dG levels (P for trend = 0.06), and a significant inverse association with urinary m7Gua levels (P for trend = 0.03). In analysis stratified by occupation, inverse correlations were observed in sedentary workers (walking < 30 min/day at work: P for trend = 0.06 and = 0.03 for urinary 8-OH-dG and m7Gua, respectively), but not in physically active workers (walking ≥ 30 min/day at work). In analysis for each intensity of leisure-time physical activity, light-intensity exercise was associated with lower levels of urinary 8-OH-dG (P for trend = 0.03), whereas moderate-to-high-intensity exercise was associated with lower levels of urinary m7Gua (P for trend = 0.02).

CONCLUSIONS

Our results suggest that high levels of leisure-time physical activity are associated with decreased levels of DNA damage in individuals with low physical activity at work.

Physical Activity and Pancreatic Cancer Risk among Urban Chinese: Results from Two Prospective Cohort Studies

Background: Associations between physical activity and pancreatic cancer risk are unclear.Methods: In two prospective cohort studies, the Shanghai Women's Health Study and Shanghai Men's Health Study, physical activity and other information were collected at the baseline interview of 72,451 women and 60,037 men. Participants were followed up through annual linkage with a cancer registry in combination with in-person interviews taking place every 2 to 4 years.Results: We identified 225 female and 159 male cases during a median follow up of 16.1 and 10.3 years, respectively. Adult exercise participation was significantly associated with a decreased pancreatic cancer risk in men [hazard ratio (HR), 95% confidence interval (CI): 0.71 (0.50-1.00)]. Meeting the recommended minimum exercise threshold to achieve health benefits of 150 min/week of moderate-intensity or 75 min/week of vigorous-intensity exercise was associated with further decreased pancreatic cancer risk [HR (95% CI): 0.59 (0.40-0.87)]. We also observed an inverse association between adolescent physical activity and pancreatic cancer risk in men [HR (95% CI): 0.54 (0.33-0.90)]. Exercise throughout one's lifetime was associated with a 68% decrease in pancreatic cancer risk [HR (95% CI): 0.32 (0.16-0.66)]. No significant association was found in women. Adult non-exercise daily activity and occupational activity were not associated with pancreatic cancer risk in either men or women.Conclusions: Adult exercise and adolescent physical activity were significantly associated with a decreased pancreatic cancer risk in men but not in women.Impact: These findings underscore the importance of investigating the possible modification by sex on the exercise and pancreatic cancer risk association. Cancer Epidemiol Biomarkers Prev; 27(4); 479-87. ©2018 AACR.

Inflammation polymorphisms and prostate cancer risk in Jamaican men: Role of obesity/body size

African ancestry and obesity are associated with higher risk of prostate cancer (PC). In a pilot study, we explored interactions between obesity (as measured by waist to hip ratio (WHR)) and inflammatory SNPs in relation to PC risk among Jamaican men. This study evaluated 87 chemokine and cytokine associated SNPs in obese and normal weight cases (N=109) and controls (N=102) using a stepwise penalized logistic regression approach in multivariable analyses. Upon stratification by WHR (normal weight (WHR<0.90) or obese (WHR≥0.90)), inheritance of CCR6 rs2023305 AG+GG (OR=1.75, p=0.007), CCR9 rs7613548 AG+GG (OR=1.71, p=0.012) and IL10ra rs2229113 AG+GG (OR=1.45, p=0.01) genotypes was associated with increase in overall or low grade (Gleason score<7) PC risk among normal weight men. These odds were elevated among obese men who possessed the CCR5 rs1799987 AG+GG (OR=1.95, p=0.003) and RNASEL rs12135247 CT+TT genotypes (OR=1.59, p=0.05). CCR7 rs3136685 AG+GG (p=0.032) was associated with a 1.52-1.70 fold increase in the risk of high grade cancer (Gleason score≥7) among obese men. CCR7 variant emerged as an important factor associated with high grade PC risk among obese men in our analyses. Overall, genetic loci found significant in normal weight men were not significant in obese men and vice-versa, partially explaining the role of obesity on PC risk among black men. Also, older age was an important risk factor both in normal weight and obese men but only with regard to low grade PC. Associations of inflammatory SNPs with obesity are suggestive and require further validation in larger cohorts to help develop an understanding of PC risk among obese and non-obese men of African descent.

Physical Exercise Positively Influences Breast Cancer Evolution

Breast cancer is one of the most commonly diagnosed types of cancer in women. Its pathogenesis involves genetic, hormonal, and environmental factors. A large body of evidence indicates that physical activity has positive effects on every aspect of breast cancer evolution, including prevention, medical treatment, and aftercare clinical settings. Thus, different types of exercise can influence the prevention and progression of the disease through several common mechanisms, such as reduction of insulin resistance and improvement of immunity and cardiovascular function. Furthermore, acute and chronic symptoms of breast cancer, such as cachexia, muscle mass loss, fatigue, cardiotoxicity, weight gain, hormone alterations, bone loss, and psychologic adverse effects, may all be favorably influenced by regular exercise. We review the relation of intensity and duration of exercise with potential pathophysiologic pathways, including obesity-related hormones and sex steroid hormone production, oxidative stress, epigenetic alterations such as DNA hypomethylation, and changes in telomere length, within the context of the beneficial effects of exercise. The potential role of exercise in reducing the intensity of the adverse effects that result from breast cancer and anticancer treatment is also discussed.

Intensity-specific effect of physical activity on urinary levels of 8-hydroxydeoxyguanosine in middle-aged Japanese

Physical activity (PA) is recommended to both promote and maintain health and prevent cancer by improving the body's DNA repair system, which is considered a mechanism of cancer prevention. However, associations between PA and urinary levels of 8-hydroxydeoxyguanosine (8-OH-dG), which reflects DNA damage, are unclear. This cross-sectional study included 2370 men and 4052 women aged 45-74 years enrolled between 2010 and 2012. Habitual PA was assessed by single-axis accelerometer and urinary 8-OH-dG levels by automated HPLC. Multiple linear regression analysis was used to examine the relationship between log-transformed urinary 8-OH-dG and total PA (TPA) and PA of moderate/vigorous intensity (MVPA; ≥3 metabolic equivalents), with adjustment for age, body mass index, energy intake, alcohol consumption, smoking status, daily coffee drinking, menopause status (in women), and TPA (for MVPA). On multivariate adjustment, urinary 8-OH-dG levels were inversely correlated with TPA (β = -0.020, P < 0.01) in women, and this correlation was not changed by PA intensity. Conversely, urinary 8-OH-dG levels were inversely correlated with MVPA (β = -0.022, P < 0.05) in men, although the correlation with TPA was non-significant. This inverse correlation was clearer in current smokers than in never or former smokers, although the interaction between smoking status and MVPA on urinary 8-OH-dG levels was non-significant. In conclusion, greater TPA in women and greater MVPA in men were correlated with reduction in urinary 8-OH-dG, suggesting sex-specific effects of MVPA and TPA on protection from oxidative DNA damage. Increasing PA may mediate reduction in oxidative stress.

Herbal Compound Songyou Yin and Moderate Swimming Suppress Growth and Metastasis of Liver Cancer by Enhancing Immune Function

Objective. Both the Chinese herbal compound Songyou Yin (SYY) and swimming exercise have been shown to have protective effects against liver cancer in animal models. In this study, we investigated whether SYY and moderate swimming (MS) have enhanced effect on suppressing progression of liver cancer by immunomodulation. Methods. C57BL/6 mice were transplanted with Hepa1-6 murine liver cancer cell lines and received treatment with SYY alone or SYY combined with MS. The green fluorescent protein (GFP)-positive metastatic foci in lungs were imaged with a stereoscopic fluorescence microscope. Flow cytometry was used to test the proportion of CD4 +, CD8 + T cells in peripheral blood and the proportions of CD4 + CD25 + Foxp3 + Treg cells in peripheral blood, spleen, and tumor tissues. Cytokine transforming growth factor (TGF)-β1 level in serum was detected by ELISA. Results. SYY plus MS significantly suppressed the growth and lung metastasis of liver cancer and prolonged survival in tumor-burdened mice. SYY plus MS markedly raised the CD4 to CD8 ratio in peripheral blood and lowered the serum TGF-β1 level and the proportions of Treg cells in peripheral blood, spleen, and tumor tissue. The effects of the combined intervention were significantly superior to SYY or MS alone. Conclusion. The combined application of SYY and MS exerted an enhanced effect on suppressing growth and metastasis of liver cancer by strengthening immunity.

Correlation of Physical Activities and Breast Cancer Characteristics: A Prospective Analysis with Special Focus on Triple Negative Breast Cancer

OBJECTIVE

Several studies have demonstrated that daily physical activity (PA) prevents the development of breast cancer. Our objective was to examine the relationship between PA and clinical and biological tumor characteristics in breast cancer patients in order to determine the impact of energy expenditure (EE) on tumor prognosis.

METHODS

We pooled data from two prospective studies, including a total of 121 breast cancer patients. The measure of PA was done using the self-completion Population Physical Activity Questionnaire, which was answered by each patient.

RESULTS

Ten patients harbored triple negative (TN) tumors. The mean body mass index (BMI) in the general population and in patients with TN tumors was 24.3 and 25.6, respectively. The mean daily EE (DEE) was 10,266 kJ×24 h(-1) in the general population and 11,212 kJ×24 h(-1) in patients with TN tumors. In the whole population, there was an inverse statistical correlation between BMI and DEE, rest, low PA, and high PA (p=0.0002, p=0.003, p<0001, and p=0.03, respectively). There was a positive correlation between negative estrogen receptor status and intensive PA (p=0.041) and DEE (p=0.007). For TN tumors, there was no significant correlation between BMI and categories of EE.

CONCLUSIONS

Lifestyle (weight regulation, PA) should be adapted and personalized according to biological, clinical, and epidemiological characteristics of the tumors.

The Association between Leisure Time Physical Activity and Pancreatic Cancer Risk in Adults: A Systematic Review and Meta-analysis

We conducted a meta-analysis of the association between leisure time physical activity (LTPA) and risk of pancreatic cancer to update previous analyses in light of newly published studies, to examine subgroups of interest and potential sources of heterogeneity. We searched the PubMed and MEDLINE databases for studies until February 2015. Study information was collected using a standardized form to abstract relevant data on study design, number of cases, participant and study characteristics, assessment of LTPA, risk estimates, and adjustments for confounding by two independent abstractors. We used random-effects models to pool estimates from included studies of lowest versus highest comparison of LTPA. The search identified 26 studies eligible for inclusion into the meta-analysis. The combined summary risk estimate was [relative risk (RR), 0.89; 95% confidence interval (CI), 0.82-0.96]. There was evidence of heterogeneity across studies (I(2) = 22.1%, Pheterogeneity = 0.130). Some of the heterogeneity could be explained by study design, with stronger protective effects observed among case-control studies (RR, 0.69; 95% CI, 0.59-0.81) compared with cohort studies (RR, 0.96; 95% CI, 0.91-1.02). Across study designs, age of population was a source of heterogeneity, with stronger effects observed among younger (<50 years) populations. The present meta-analysis supports a protective association between LTPA and pancreatic cancer with an 11% risk reduction observed. LTPA appears to have the strongest effect among young populations. Additional investigations are needed to provide insights regarding the impact of LTPA in healthy adult populations, to reduce the risk of pancreatic cancer and encourage increases in LTPA.

Maternal exercise during pregnancy reduces risk of mammary tumorigenesis in rat offspring

Breast cancer is the most common cancer among women. Emerging research indicates that modifying lifestyle factors during pregnancy may convey long-term health benefits to offspring. This study was designed to determine whether maternal exercise during pregnancy leads to reduced mammary tumorigenesis in female offspring. Pregnant rats were randomly assigned to exercised and sedentary groups, with the exercised group having free access to a running wheel and the sedentary group housed with a locked wheel during pregnancy. Female pups from exercised or sedentary dams were weaned at 21 days of age and fed a high fat diet without access to a running wheel. At 6 weeks, all pups were injected with the carcinogen N-methyl-N-nitrosourea. Mammary tumor development in all pups was monitored for 15 weeks. Pups from exercised dams had a substantially lower tumor incidence (42.9%) compared with pups from sedentary dams (100%). Neither tumor latency nor histological grade differed between the two groups. These data are the first to demonstrate that exercise during pregnancy potentiates reduced tumorigenesis in offspring. This study provides an important foundation towards developing more effective modes of behavior modification for cancer prevention.

Lipidomic profiling of di- and tri-acylglycerol species in weight-controlled mice

Weight control by dietary calorie restriction (DCR) or exercise has been shown to prevent cancer in various models. However, the mechanisms as to how weight control is beneficial are not well understood. While previous reports have investigated the effects of weight control on total lipid levels or lipid composition within cellular membranes, there has been little work surrounding changes to individual lipids following weight control interventions. In this study, using a model of skin carcinogenesis centered on the tumor promotion stage, CD-1 mice were randomly assigned into 4 groups: ad libitum and sedentary (control), ad libitum with exercise (AL+Exe), exercise with pair feeding of a diet isocaloric with control (PF+Exe), and sedentary with 20% DCR compared to control. After ten weeks, body weight and body fat percentages significantly decreased in the PF+Exe and DCR groups but not AL+Exe when compared with sedentary controls. Murine skin and plasma samples were obtained for analysis. Lipidomics using electrospray ionization MS/MS was employed to profile triacylglycerol (TG) and diacylglycerol (DG) species. Both plasma and tissue TG species containing fatty acid chains with length 18:1 were significantly decreased following DCR when compared to sedentary control animals. In regards to DG, the most significant changes occurred in the plasma. DG species containing fatty acids with lengths 16:1 or 18:1 were significantly decreased in PF+Exe and DCR groups when compared to sedentary controls. Due to the significant role of TG in energy storage and DG in cellular signaling, our findings of the effects of weight control on individual TG and DG species in plasma and skin tissue following exposure to a tumor promoter, may provide insight into the mechanism of weight control on cancer prevention.

Exercise training combined with antioxidant supplementation prevents the antiproliferative activity of their single treatment in prostate cancer through inhibition of redox adaptation

In preclinical models, exercise training (ET) or pomegranate juice (PJ) prevents prostate cancer progression. Here, we hypothesized that physical exercise combined with antioxidants could induce synergistic effects through oxidative stress modulation. Forty male Copenhagen rats with prostate tumors were divided into four groups: control, PJ, ET, and PJ+ET. Rats from the PJ group consumed 750 µl of PJ daily, rats from the ET group ran on a treadmill 5 days per week, and PJ+ET rats received the combined treatment. Each week, tumor growth was evaluated. After 4 weeks of treatment, the rats were euthanized and blood, muscles, and tumors were collected. Tumor Ki67, extracellular signal-regulated kinase (ERK) activation, Bcl-2 expression, and enzymatic and nonenzymatic antioxidant defenses, as well as oxidative stress markers (oxidized base, lipid peroxidation, protein carbonylation), were measured. PJ or ET significantly decreased prostate tumor proliferation (Ki67 staining, p<0.05) through the modulation of ERK phosphorylation, whereas the combination of treatments did not limit cancer progression. PJ significantly reduced Bcl-2 expression in tumors (p<0.05) and the combination of PJ and ET prevented this effect. PJ or ET increased enzymatic antioxidant defenses in muscle, PJ increased nonenzymatic antioxidant defenses in plasma and whole blood. In addition, PJ reduced TBARS and 8-oxodGuo levels in tumors as well as ET (p<0.05), whereas protein carbonyl levels were not affected by these two strategies. Paradoxically, association of PJ+ET did not increase antioxidant defenses and no reduction in oxidative stress markers was induced. Loading cancer cells with antioxidants blunts the positive effects of ET and interferes with important reactive oxygen species-mediated physiological processes such as antioxidant adaptations.

Exercise: putting action into our epigenome

Most human phenotypes are influenced by a combination of genomic and environmental factors. Engaging in regular physical exercise prevents many chronic diseases, decreases mortality risk and increases longevity. However, the mechanisms involved are poorly understood. The modulating effect of physical (aerobic and resistance) exercise on gene expression has been known for some time now and has provided us with an understanding of the biological responses to physical exercise. Emerging research data suggest that epigenetic modifications are extremely important for both development and disease in humans. In the current review, we summarise findings on the effect of exercise on epigenetic modifications and their effects on gene expression. Current research data suggest epigenetic modifications (DNA methylation and histone acetylation) and microRNAs (miRNAs) are responsive to acute aerobic and resistance exercise in brain, blood, skeletal and cardiac muscle, adipose tissue and even buccal cells. Six months of aerobic exercise alters whole-genome DNA methylation in skeletal muscle and adipose tissue and directly influences lipogenesis. Some miRNAs are related to maximal oxygen consumption (VO(2max)) and VO(2max) trainability, and are differentially expressed amongst individuals with high and low VO(2max). Remarkably, miRNA expression profiles discriminate between low and high responders to resistance exercise (miR-378, -26a, -29a and -451) and correlate to gains in lean body mass (miR-378). The emerging field of exercise epigenomics is expected to prosper and additional studies may elucidate the clinical relevance of miRNAs and epigenetic modifications, and delineate mechanisms by which exercise confers a healthier phenotype and improves performance.

Psoriasis and sport: a new ally?

BACKGROUND

Psoriasis is a common chronic multifactorial disease which can result in restrictions to social and recreational activities. Psoriasis subjects are at high risk to develop metabolic and cardiovascular diseases. Physical activity, a vital component in prevention and management of these diseases, is reported to be potentially associated in a negative way with psoriasis.

OBJECTIVE

To investigate the relationship between psoriasis and physical activity.

MATERIALS AND METHODS

Anamnestic and physical examination as well as a specific doctor-administered questionnaire was performed to a group of 416 consecutive sportive subjects and 489 sex and age-matched controls. Moreover, similar investigations were executed on 400 consecutive psoriatic patients without psoriatic arthritis.

RESULTS

Psoriasis was significantly more common in controls respect to sportive group (n = 27, 5.4% vs. n = 7, 1.7%, P < 0.01) whereas a positive familial history of psoriasis was observed in similar percentages in both groups (n = 51, 10.2% vs. n = 40, 9.6%). The number of subjects performing sports activities was significantly lower in psoriasis group compared to controls (n = 44, 11% vs. n = 106, 21.3%; P < 0.001). Of these psoriatic patients, 35/44 referred that sporting activities showed a positive influence on the natural course of their disease, whereas the remaining 11 patients did not highlight positive or negative influences on their illness. Interestingly, 23.75% of psoriatic patients (n = 95) related that they had regularly carried out sporting activities before the onset of the dermatosis referring that psoriasis represented a huge obstacle to continue practicing physical activities.

CONCLUSION

Our survey showed that regular physical activity may lower the risk of psoriasis and have a beneficial effect on the natural course of the disease, positively influencing not only the severity as well as the incidence of metabolic comorbidities, but also, through possible epigenomic, metabolic, anti-inflammatory and psycho-emotional effects, the onset of the dermatosis. However, larger birth cohort studies are needed to confirm these results.

Physical activity is associated with reduced risk of esophageal cancer, particularly esophageal adenocarcinoma: a systematic review and meta-analysis

Background

Physical activity has been inversely associated with risk of several cancers. We performed a systematic review and meta-analysis to evaluate the association between physical activity and risk of esophageal cancer (esophageal adenocarcinoma [EAC] and/or esophageal squamous cell carcinoma [ESCC]).

Methods

We conducted a comprehensive search of bibliographic databases and conference proceedings from inception through February 2013 for observational studies that examined associations between recreational and/or occupational physical activity and esophageal cancer risk. Summary adjusted odds ratio (OR) estimates with 95% confidence intervals (CI) were estimated using the random-effects model.

Results

The analysis included 9 studies (4 cohort, 5 case–control) reporting 1,871 cases of esophageal cancer among 1,381,844 patients. Meta-analysis demonstrated that the risk of esophageal cancer was 29% lower among the most physically active compared to the least physically active subjects (OR, 0.71; 95% CI, 0.57-0.89), with moderate heterogeneity (I² = 47%). On histology-specific analysis, physical activity was associated with a 32% decreased risk of EAC (4 studies, 503 cases of EAC; OR, 0.68; 95% CI, 0.55-0.85) with minimal heterogeneity (I² = 0%). There were only 3 studies reporting the association between physical activity and risk of ESCC with conflicting results, and the meta-analysis demonstrated a null association (OR, 1.10; 95% CI, 0.21-5.64). The results were consistent across study design, geographic location and study quality, with a non-significant trend towards a dose–response relationship.

Conclusions

Meta-analysis of published observational studies indicates that physical activity may be associated with reduced risk of esophageal adenocarcinoma. Lifestyle interventions focusing on increasing physical activity may decrease the global burden of EAC.

Oxidative balance score and risk for incident prostate cancer in a prospective U.S. cohort study

PURPOSE

Oxidative stress is defined as an imbalance between pro-oxidants and antioxidants. Previous research found that a single comprehensive oxidative balance score (OBS) that includes individual pro- and anti-oxidant exposures may be associated with various conditions (including prostate cancer) in the absence of associations with the individual factors. We investigated an OBS-incident prostate cancer association among 43,325 men in the Cancer Prevention Study II Nutrition Cohort.

METHODS

From 1999-2007, 3386 incident cases were identified. Twenty different components, used in two ways (unweighted or weighted based on literature reviews), were incorporated into the OBS, and the resulting scores were then expressed as three types of variables (continuous, quartiles, or six equal intervals). Multivariable-adjusted rate ratios were calculated using Cox proportional hazards models.

RESULTS

We hypothesized that the OBS would be inversely associated with prostate cancer risk; however, the rate ratios (95% confidence intervals) comparing the highest with the lowest OBS categories ranged from 1.17 (1.04-1.32) to 1.39 (0.90-2.15) for all cases, 1.14 (0.87-1.50) to 1.59 (0.57-4.40) for aggressive disease (American Joint Committee on Cancer stage III/IV or Gleason score 8-10), and 0.91 (0.62-1.35) to 1.02 (1.02-1.04) for nonaggressive disease.

CONCLUSIONS

Our findings are not consistent with the hypothesis that oxidative balance-related exposures collectively affect risk for prostate cancer.

Possible relations between oxidative damage and apoptosis in benign prostate hyperplasia and prostate cancer patients

Cancer has been described as the twentieth century plague, and is a very common health problem. It has been reported that ROS and ROS products play a key role in cancer and that oxidative damage is effective in apoptosis initiation. In this study we aimed to evaluate the relationship between MDA (malondialdehyde), DNA damage (8-hydroxyguanine, 8-OH-dG), and caspase-3 in BHP and prostate cancer patients. Twenty male patients with prostate cancer and 20 male patients with benign prostate hyperplasia were included into this study. The MDA (nanomole), DNA damage (nanograms per millilitre), and caspase-3 (nanograms per millilitre) levels were measured in prostate cancer and benign prostate hyperplasia using Elisa kits (Millipore Corporation, Billerica, MA, USA). In the prostate cancer group, serum MDA (30.96 ± 9.25) and DNA damage (4.42 ± 0.36) levels were significantly raised (p < 0.05) when compared to the benign prostate hyperplasia group (24.05 ± 8.06, 3.99 ± 0.54). However, in the prostate cancer group, serum caspase-3 (2.36 ± 0.82) levels were statistically significantly lowered (p < 0.05) compared with the benign prostate hyperplasia group (3.15 ± 1.04). We observed that altered prooxidant, DNA damage levels may lead to an increase in oxidative damage and may consequently play an important role in prostate carcinogenesis. These findings indicate that, although the triggering of these changes is unknown, changes in the levels of MDA, DNA damage, and caspase-3 in the blood are related to prostatic carcinoma development. In addition, it would be appropriate to conduct new studies with a large number of patients at different stages.

Physical activity and gastric cancer: so what? An epidemiologist's confession

Epidemiologists, like many scientists, tend to become specialized and focused on a particular disease, even though behavioral risk factors such as physical activity have effects across many diseases. This commentary is a personal reflection by an epidemiologist on the shortcomings of this disease-oriented approach to prevention.

Effects of 47C allele (rs4880) of the SOD2 gene in the production of intracellular reactive species in peripheral blood mononuclear cells with and without lipopolysaccharides induction

Challenging of peripheral blood mononuclear cells (PBMCs) with lipopolysaccharides (LPS) has been shown to activate monocytes and macrophages, leading to the production of pro-inflammatory cytokines and reactive oxygen species (ROS). Manganese superoxide dismutase (MnSOD) is an important enzyme that may play a central role in the response to oxidative stress. 47C> T SNP of the SOD2 gene, the -9Val MnSOD is less efficient than the -9Ala version. We have previously characterized the cellular redox status of human PBMCs expressing either -9Ala (CC) or -9Val (TT) SOD2 and analyzed the responses of these cells to oxidative stress induced by LPS. Due to the observed alterations in the activities of these antioxidant enzymes, we decided to investigate their immunocontent and analyze the production of intracellular oxidants, as well as any resulting DNA damage. PBMCs were isolated from the blood of 30 healthy human volunteers (15 volunteers per allele). We then analyzed levels of nitrite, DNA damage by comet assay, TNF-α, carboxymethyl lysine and nitrotyrosine and assessed production of intracellular reactive species by the DCFH-DA-based assay and western blots were used to analyze protein levels. Our results show that there occurs an increase in nitric oxide production in both allele groups after challenge with LPS. A significant increase in DNA damage was observed in PBMCs after an 8-h LPS challenge. Cells expressing the SOD2 47C allele quickly adapt to a more intense metabolism by upregulating cellular detoxification mechanisms. However, when these cells are stressed over a long period, they accumulate a large quantity of toxic metabolic byproducts.

Lung cancer: what are the links with oxidative stress, physical activity and nutrition

Oxidative stress appears to play an essential role as a secondary messenger in the normal regulation of a variety of physiological processes, such as apoptosis, survival, and proliferative signaling pathways. Oxidative stress also plays important roles in the pathogenesis of many diseases, including aging, degenerative disease, and cancer. Among cancers, lung cancer is the leading cause of cancer in the Western world. Lung cancer is the commonest fatal cancer whose risk is dependent on the number of cigarettes smoked per day as well as the number of years smoking, some components of cigarette smoke inducing oxidative stress by transmitting or generating oxidative stress. It can be subdivided into two broad categories, small cell lung cancer and non-small-cell lung cancer, the latter is the most common type. Distinct measures of primary and secondary prevention have been investigated to reduce the risk of morbidity and mortality caused by lung cancer. Among them, it seems that physical activity and nutrition have some beneficial effects. However, physical activity can have different influences on carcinogenesis, depending on energy supply, strength and frequency of exercise loads as well as the degree of exercise-mediated oxidative stress. Micronutrient supplementation seems to have a positive impact in lung surgery, particularly as an antioxidant, even if the role of micronutrients in lung cancer remains controversial. The purpose of this review is to examine lung cancer in relation to oxidative stress, physical activity, and nutrition.

Physical activity is associated with reduced risk of gastric cancer: a systematic review and meta-analysis

Physical activity may be associated with reduced risk of gastric cancer. We performed a systematic review and meta-analysis to evaluate the magnitude of the association and the quality of supporting evidence. After a comprehensive search of bibliographic databases and conference proceedings through February 2013 for observational studies that examined associations between recreational and/or occupational physical activity and gastric cancer risk, we identified 16 studies (seven cohort, nine case control) reporting 11,111 cases of gastric cancer among 1,606,760 patients. Summary adjusted-OR estimates with 95% confidence intervals (CI) were estimated using the random-effects model. Meta-analysis demonstrated that the risk of gastric cancer was 21% lower among the most physically active people as compared with the least physically active people (OR = 0.79; 95% CI, 0.71-0.87) with moderate heterogeneity among studies (I(2) = 55%). This protective effect was seen for gastric cancers in the cardia (four studies; OR = 0.80; 95% CI, 0.63-1.00) and distal stomach (five studies; OR = 0.63; 95% CI, 0.52-0.76). The effect size was significantly smaller in high-quality studies (six studies; OR = 0.86; 95% CI, 0.75-0.99), as compared with low-quality studies (10 studies; OR = 0.74; 95% CI, 0.69-0.81). The results were consistent across sex, study quality, study design, and geographic location. In conclusion, meta-analysis of published observational studies indicates that physical activity is associated with reduced risk of gastric cancer. Lifestyle interventions focusing on increasing physical activity may decrease the global burden of gastric cancer, in addition to a myriad of other health benefits.

Exercise does not counteract the effects of a "westernized" diet on prostate cancer xenografts

BACKGROUND

The relationships between diet, exercise, and prostate cancer (PCa) remain unclear. We have previously reported that a "Western" diet promotes PCa tumor growth in vivo. Presently, we report the effects of sustained aerobic exercise on PCa progression in animals fed a high-fat diet versus a standard diet.

METHODS

Athymic mice (n = 43) were inoculated subcutaneously with human PCa (LNCaP) cells, fed ad libitum with either a high-fat or a standard diet, and randomized into forced exercising and non-exercising groups. Body weight, tumor volume, and food consumption were recorded tri-weekly. Terminal serum samples and tumor biopsies were obtained for analysis.

RESULTS

Body weight differences were not observed between the groups over time. The high-fat diet with exercise (HF-Ex) group showed significantly increased tumor growth rate compared to all other groups (P < 0.0007). Tumor growth rate of the standard diet with exercise (Std-Ex) group was reduced significantly compared to the high-fat diet without exercise (HF-No Ex) group (P = 0.0008). Significant differences (P ≤ 0.012) were observed in energy consumption (kcal) between the groups over time. Exercising mice consumed significantly more kcal than non-exercising mice, and the HF-Ex group consumed significantly more than each of the other three groups (P < 0.0007). The expression levels of p27 and p21 were increased in exercising animals, while AR expression was elevated in the HF-Ex group versus the Std-Ex and HF-No Ex groups.

CONCLUSIONS

Sustained aerobic exercise did not counteract the tumor-promotional effect of increased consumption of a high-fat diet, suggesting that diet is more influential in PCa progression than exercise. Combining exercise with a healthy diet reduced the rate of PCa progression in this model. This study may have implications for PCa risk reduction in humans.

Association between chronological change of reproductive factors and breast cancer risk defined by hormone receptor status: results from the Seoul Breast Cancer Study

Lifestyle factors have been chronologically changed into western style ones, which could result in the rapid increase of breast cancer incidence in Korea. It is plausible that reproductive factors through hormonal mechanisms are differentially related to the risk of breast cancer subtypes. We investigated the association of reproductive risk factors on breast cancer by birth year groups and also evaluated the differential associations on the hormone receptor-defined subtypes. Using the data from the Seoul Breast Cancer Study (SeBCS), a multicenter case-control study, 3,332 breast cancer patients and 3,620 control subjects were analyzed. The distribution of subtypes among cases was as follows: 61.0 % estrogen receptor (ER)-positive, 51.9 % progesterone receptor (PR)-positive, and 43.4 % both ER/PR-positive status, respectively. Polytomous logistic regression and Wald tests for heterogeneity have been used across the subtypes. The frequencies of reproductive-related risk factors including early age at menarche, nulligravid, age at first full-term pregnancy (FFTP), duration of estrogen exposure before FFTP (EEBF), less number of children, never breastfeeding, and short duration of breastfeeding has increased as women were born later in both cases and controls, respectively (p trend < 0.0001. Among breast cancer patients, either ER- or PR-positive subtypes were increased in women born in 1960s compared to women born in 1940s. Early age at menarche increased the risk of breast cancer regardless of the subtypes while nulligravid, late age at FFTP, and longer duration of EEBP were associated with hormone receptor-positive cancer risk only (p heterogeneity < 0.05), which associations were stronger among women born later. Our results suggest that the associations of age at menarche, parity, age at FFTP, and duration of EEBF with breast cancer risk were different based on the hormone receptor status and birth year groups in Korea.

Tobacco, alcohol, body mass index, physical activity, and the risk of head and neck cancer in the prostate, lung, colorectal, and ovarian (PLCO) cohort

BACKGROUND

Estimation of attributable fractions for tobacco and alcohol, and investigation of the association between body mass index (BMI) and head and neck cancer risk have largely been in case-control studies. These aspects and physical activity need to be assessed as possible head and neck cancer risk/protective factors in a cohort study.

METHODS

In the Prostate, Lung, Colorectal, and Ovarian (PLCO) cancer screening trial, of the 101,182 study subjects, 177 individuals developed head and neck cancer.

RESULTS

The proportion of head and neck cancer cases attributed to tobacco and/or alcohol was 66% (50.5% tobacco alone, 14.7% alcohol alone, 0.9% tobacco and alcohol combined). BMI was not associated with head and neck cancer risk, but increasing hours of physical activity per week was associated with a reduced head and neck cancer risk (odds ratio [OR] = 0.58; 95% confidence interval [CI] = 0.35-0.96).

CONCLUSIONS

Cigarette smoking is clearly the most important head and neck cancer risk factor in this population. The reduced cancer risk due to physical activity was consistent with results from a pooled analysis of case-control studies.

Targeting the therapeutic effects of exercise on redox-sensitive mechanisms in the vascular endothelium during tumor progression

The American Cancer Society estimated 1.5 million new cancer cases in the United States in 2012. Although the exact number is not known, it is estimated that brain metastases occur in 20-40% of cancer patients (39). Owing to the complexity of development and the variation in tumor etiology, therapy options have been limited for a number of cancers, whereas progressive treatments have been successful for some malignancies. Combining treatment strategies has shown potential to increase positive outcomes; however, cancer remains a formidable diagnosis with no true cure. Many researchers have focused on alternative forms of cancer prevention or treatment to slow cancer progression. Studies have shown that with moderate, regular exercise signaling pathways associated with increased antioxidant activity and cellular repair are upregulated in vascular tissue; however, the physiological mechanisms are poorly understood. The purpose of this review is to examine the current literature to better understand the impact of exercise on cancer progression and tumor metastasis and discuss potential redox-related signaling in the vasculature that may be involved.

Identifying molecular targets of lifestyle modifications in colon cancer prevention

One in four deaths in the United States is cancer-related, and colorectal cancer (CRC) is the second leading cause of cancer-associated deaths. Screening strategies are utilized but have not reduced disease incidence or mortality. In this regard, there is an interest in cancer preventive strategies focusing on lifestyle intervention, where specific etiologic factors involved in cancer initiation, promotion, and progression could be targeted. For example, exposure to dietary carcinogens, such as nitrosamines and polycyclic aromatic hydrocarbons influences colon carcinogenesis. Furthermore, dietary deficiencies could alter sensitivity to genetic damage and influence carcinogen metabolism contributing to CRC. High alcohol consumption increases the risk of mutations including the fact that acetaldehyde, an ethanol metabolite, is classified as a group 1 carcinogen. Tobacco smoke exposure is also a risk factor for cancer development; approximately 20% of CRCs are associated with smoking. Additionally, obese patients have a higher risk of cancer development, which is further supported by the fact that physical activity decreases CRC risk by 55%. Similarly, chronic inflammatory conditions also increase the risk of CRC development. Moreover, the circadian clock alters digestion and regulates other biochemical, physiological, and behavioral processes that could influence CRC. Taken together, colon carcinogenesis involves a number of etiological factors, and therefore, to create effective preventive strategies, molecular targets need to be identified and beleaguered prior to disease progression. With this in mind, the following is a comprehensive review identifying downstream target proteins of the above lifestyle risk factors, which are modulated during colon carcinogenesis and could be targeted for CRC prevention by novel agents including phytochemicals.

Regular recreational physical activity and risk of hematologic malignancies: results from the prospective VITamins And lifestyle (VITAL) study

BACKGROUND

Conflicting evidence exists on the relationship between physical activity (PA) and incident hematologic malignancies. Herein, we used a large cohort study to examine this association.

PATIENTS AND METHODS

Sixty-five thousand three hundred twenty-two volunteers aged 50-76 years were recruited from 2000 to 2002. Incident hematologic malignancies (n = 666) were identified through 2009 by linkage to the Surveillance, Epidemiology, and End Results cancer registry. Hazard ratios (HRs) for hematologic malignancies associated with PA averaged over 10 years before baseline were estimated with Cox proportional hazards models, adjusting for factors associated with hematologic cancers or PA.

RESULTS

There was a decreased risk of hematologic malignancies associated with PA (HR = 0.66 [95% confidence interval, 95% CI 0.51-0.86] for the highest tertile of all PA, P-trend = 0.005, and HR = 0.60 [95% CI 0.44-0.82] for the highest tertile of moderate/high-intensity PA, P-trend = 0.002). These associations were strongest for myeloid neoplasms (HR = 0.48 [95% CI 0.29-0.79] for the highest tertile of all PA, P-trend = 0.013, and HR = 0.40 [95% CI 0.21-0.77] for the highest tertile of moderate/high-intensity PA, P-trend = 0.016). There were also significant associations between PA and chronic lymphocytic leukemia/small lymphocytic lymphoma or other mature B-cell lymphomas except plasma cell disorders.

CONCLUSIONS

Our study offers the strongest epidemiological evidence, to date, to suggest an association between regular PA and dose-dependent risk reduction for most hematologic malignancies, particularly myeloid neoplasms.

Aromatase inhibitor-induced arthralgia: a review

Though aromatase inhibitors (AIs) are an essential part of estrogen receptor-positive (ER+) breast cancer therapy, many patients discontinue the medicine before their adjuvant therapy is completed because of the arthralgia which often accompanies the medicine. Up to half of women on AI therapy experience joint pain, and up to 20% will become non-compliant with the medicine because of the joint pain. Yet, very little is known about what causes AI-induced arthralgia (AIA), and there is no established, effective treatment for this difficult problem. It compromises survivors' quality of life and leads to non-compliance. This paper will discuss AIA in depth, including potential etiologies, clinical significance, risk factors, and possible management solutions. Of note, this article presents one of the first proposed algorithms which clearly lays out a treatment plan for AIA, incorporating a variety of interventions which have been proven by the available literature.

Bridging the gap between biologic, individual, and macroenvironmental factors in cancer: a multilevel approach

To address the complex nature of cancer occurrence and outcomes, approaches have been developed to simultaneously assess the role of two or more etiologic agents within hierarchical levels including the: (i) macroenvironment level (e.g., health care policy, neighborhood, or family structure); (ii) individual level (e.g., behaviors, carcinogenic exposures, socioeconomic factors, and psychologic responses); and (iii) biologic level (e.g., cellular biomarkers and inherited susceptibility variants). Prior multilevel approaches tend to focus on social and environmental hypotheses, and are thus limited in their ability to integrate biologic factors into a multilevel framework. This limited integration may be related to the limited translation of research findings into the clinic. We propose a "Multi-level Biologic and Social Integrative Construct" (MBASIC) to integrate macroenvironment and individual factors with biology. The goal of this framework is to help researchers identify relationships among factors that may be involved in the multifactorial, complex nature of cancer etiology, to aid in appropriate study design, to guide the development of statistical or mechanistic models to study these relationships, and to position the results of these studies for improved intervention, translation, and implementation. MBASIC allows researchers from diverse fields to develop hypotheses of interest under a common conceptual framework, to guide transdisciplinary collaborations, and to optimize the value of multilevel studies for clinical and public health activities.

Health-related factors associated with mode of travel to work

Active commuting (AC) to the workplace is a potential strategy for incorporating physical activity into daily life and is associated with health benefits. This study examined the association between health-related factors and mode of travel to the workplace. Methods. A volunteer convenience sample of employed adults completed an online survey regarding demographics, health-related factors, and the number of times/week walking, biking, driving, and using public transit to work (dichotomized as no walk/bike/drive/PT and walk/bike/drive/PT 1 + x/week). Logistic regression was used to predict the likelihood of each mode of transport and meeting PA recommendations from AC according to demographics and health-related factors. Results. The sample (n = 1175) was aged 43.5 ± 11.4 years and was primarily White (92.7%) and female (67.9%). Respondents reported walking (7.3%), biking (14.4%), taking public transit (20.3%), and driving (78.3%) to work at least one time/week. Among those reporting AC, 9.6% met PA recommendations from AC alone. Mode of travel to work was associated with several demographic and health-related factors, including age, number of chronic diseases, weight status, and AC beliefs. Discussion. Mode of transportation to the workplace and health-related factors such as disease or weight status should be considered in future interventions targeting AC.

Cancer risk in systemic lupus: an updated international multi-centre cohort study

OBJECTIVE

To update estimates of cancer risk in SLE relative to the general population.

METHODS

A multisite international SLE cohort was linked with regional tumor registries. Standardized incidence ratios (SIRs) were calculated as the ratio of observed to expected cancers.

RESULTS

Across 30 centres, 16,409 patients were observed for 121,283 (average 7.4) person-years. In total, 644 cancers occurred. Some cancers, notably hematologic malignancies, were substantially increased (SIR 3.02, 95% confidence interval, CI, 2.48, 3.63), particularly non-Hodgkin's lymphoma, NHL (SIR 4.39, 95% CI 3.46, 5.49) and leukemia. In addition, increased risks of cancer of the vulva (SIR 3.78, 95% CI 1.52, 7.78), lung (SIR 1.30, 95% CI 1.04, 1.60), thyroid (SIR 1.76, 95% CI 1.13, 2.61) and possibly liver (SIR 1.87, 95% CI 0.97, 3.27) were suggested. However, a decreased risk was estimated for breast (SIR 0.73, 95% CI 0.61-0.88), endometrial (SIR 0.44, 95% CI 0.23-0.77), and possibly ovarian cancers (0.64, 95% CI 0.34-1.10). The variability of comparative rates across different cancers meant that only a small increased risk was estimated across all cancers (SIR 1.14, 95% CI 1.05, 1.23).

CONCLUSION

These data estimate only a small increased risk in SLE (versus the general population) for cancer over-all. However, there is clearly an increased risk of NHL, and cancers of the vulva, lung, thyroid, and possibly liver. It remains unclear to what extent the association with NHL is mediated by innate versus exogenous factors. Similarly, the etiology of the decreased breast, endometrial, and possibly ovarian cancer risk is uncertain, though investigations are ongoing.

Methodological issues when analysing the role of physical activity in gastric cancer prevention: a critical review

The beneficial effect of physical activity (PA) has been confirmed in several types of cancer (especially colon and breast tumours). However, the role of PA as a risk factor directly related to the incidence of gastric cancer is still open to doubt. This is in part due to the fact that most studies have not considered gastric sub-site or histology of oesophageal cancer, as well as the different approaches used in order to measure PA. Indeed, some studies have tried to link gastric cancer to PA intensity and timing, whereas others have focused on a specific PA type such as recreational, occupational or sporting activity. Furthermore, most of them do not use validated questionnaires, and others create a PA index and employ different unit measures (metabolic equivalents, hours/week, times per week, etc.), which makes it difficult to compare its findings. Under these circumstances, this brief critical review aims to explore and show all the methodological issues that need to be taken into account in order to objectify the link between PA and gastric cancer, as well as provide alternative solutions to these matters.

Effects of swim training on liver carcinogenesis in male Wistar rats fed a low-fat or high-fat diet

The present study aimed to investigate the beneficial effects of swim training on the promotion–progression stages of rat liver carcinogenesis. Male Wistar rats were submitted to chemically induced liver carcinogenesis and allocated into 4 major groups, according their dietary regimen (16 weeks) and swim training of 5 days per week (8 weeks): 2 groups were fed low-fat diet (LFD, 6% fat) and trained or not trained and 2 groups were fed high-fat diet (HFD, 21% fat) and trained or not trained. At week 20, the animals were killed and liver samples were processed for histological analyses; immunohistochemical detection of persistent or remodeling preneoplastic lesions (pPNL and rPNL) expressing placental glutathione S-transferase (GST-P) enzyme; or proliferating cell nuclear antigen (PCNA), cleaved caspase-3, and bcl-2 protein levels by Western blotting or malonaldehyde (MDA) and total glutathione detection by HPLC. Overall analysis indicated that swim training reduced the body weight and body fat in both LFD and HFD groups, normalized total cholesterol levels in the HFD group while decreased the MDA levels, increased glutathione levels and both number of GST-P-positive pPNL and hepatocellular adenomas in LFD group. Also, a favorable balance in PCNA, cleaved caspase-3, and bcl-2 levels was detected in the liver from the LFD-trained group in relation to LFD-untrained group. The findings of this study indicate that the swim training protocol as a result of exercise postconditioning may attenuate liver carcinogenesis under an adequate dietary regimen with lowered fat intake.