A healthy lifestyle index and its association with risk of breast, endometrial, and ovarian cancer among Canadian women

Lifestyle Quality Indices and Female Breast Cancer Risk: A Systematic Review and Meta-Analysis

Breast cancer (BC) poses an important burden of disease, which probably could be reduced by adopting healthy lifestyles like healthy body weight, healthy diet, and physical activity, among others. Many studies have reported that adherence to healthy lifestyles may decrease BC risk. The main objective of this study was to estimate a summary association of studies evaluating a healthy lifestyle index and BC risk. A systematic review and meta-analysis following the Cochrane methodology were carried out. Observational studies, including healthy lifestyle indices and their association with BC, were searched from 4 databases. For the meta-analysis, random-effects model was used to evaluate overall BC risk, BC by molecular subtype and menopausal status. Thirty-one studies were included in the systematic review, and 29 studies in the meta-analysis. When the highest vs. the lowest category to a healthy lifestyle index were compared, the study identified a 20% risk reduction for BC in prospective studies (hazard ratio [HR] 0.80 95% CI: 0.78, 0.83) and an odds ratio (OR) of 0.74 (95% CI: 0.63, 0.86) for retrospective studies. The inverse association remained statistically significant when stratified by menopausal status, except for premenopausal BC in prospective studies. Furthermore, an inverse association was found for molecular subtypes estrogen receptor (ER+)/progesterone receptor (PR+): HR = 0.68 (95%CI: 0.63, 0.73), ER+/PR-: HR = 0.78 (95% CI: 0.67, 0.90) and ER-/PR-: HR = 0.77 (95% CI: 0.64, 0.92). Most studies scored at a low risk of bias and a moderate score for the certainty of the evidence. Adherence to a healthy lifestyle reduces the risk of BC, regardless of its molecular subtypes, which should be considered a priority to generate recommendations for BC prevention at a population level. International prospective register of systematic reviews (PROSPERO) ID: CRD42021267759.

The association of a combined healthy lifestyle with the risk of postmenopausal breast cancer subtypes in the Netherlands Cohort Study

The association between combined healthy lifestyle and postmenopausal breast cancer risk has been studied in various cohort studies, but only few evaluated the association with estrogen/progesterone (ER/PR) receptor subtypes of breast cancer, with inconsistent results. The relationship of a healthy lifestyle score (HLS) with risk of postmenopausal breast cancer (subtypes) was investigated in the Netherlands Cohort Study. In 1986, 62,573 women aged 55-69 years provided information on dietary and lifestyle habits. The HLS was derived from information on smoking, body mass index, physical activity, Mediterranean diet adherence, and alcohol intake. After 20.3 years of follow-up, multivariable case-cohort analyses were based on 2321 incident breast cancer cases, and 1665 subcohort members with complete data on lifestyles and confounders. The HLS showed a statistically significant inverse relationship with postmenopausal breast cancer risk, in a linear fashion. A one-point increment of the HLS was accompanied by a Hazard Ratio (HR) reduction of 20% for overall breast cancer. The associations between HLS and risk of ER/PR breast cancer subtypes were also significantly inverse, except for ER- breast cancer where the inverse association did not reach statistical significance. Per HLS-increment of one point, the HR reduction ranged from 14% for ER-breast cancer to 29% for ER + PR- breast cancer. These findings suggest that adhering to a combination of healthy modifiable lifestyle factors may substantially reduce the risk of overall postmenopausal breast cancer and its hormone receptor subtypes.

Comprehensive workplace intervention for cancer prevention in China (WECAN): protocol for a stepped-wedge, cluster-randomised controlled trial

INTRODUCTION

Cancer is the second leading cause of death across the globe with the majority of deaths occurring in low-income and middle-income countries. Evidence has shown that the cancer burden can be substantially reduced by avoiding behavioural risk factors through comprehensive intervention strategies, including workplace health promotion, which has shown to be cost-effective in developed countries while rarely conducted in developing countries. This study aims to explore a feasible and sustainable approach to the prevention and control of cancer in China by developing an evidence-based comprehensive workplace health model equipped with a smartphone application for implementation.

METHODS AND ANALYSIS

This study is designed as a stepped-wedge, cluster-randomised controlled trial. We will recruit 15 workplaces from three cities in China. A total of 750 employees will be randomly selected for evaluation that includes five rounds of survey conducted every 6 months. After the second evaluation, workplaces will be randomly allocated to start the intervention sequentially every 6 months in three steps with five workplaces per step. A mobile application 'Healthy Workplace' will be developed to support the intervention. On-line and off-line health-related activities will be carried out among employees. Employers will provide supportive policies, environment and benefits to facilitate the adoption of healthy behaviours. The primary outcome is the change of Healthy Lifestyle Index Score, which consists of five components including smoking, alcohol drinking, physical activity, diet and body mass index.

ETHICS AND DISSEMINATION

The study has been approved by Queen Mary University of London Ethics of Research Committee (QMERC22.257) and Chinese Centre for Disease Control and Prevention Institutional Review Board (202210). Written informed consent is required from all participants. Results will be disseminated through presentations, publications and social media.

TRIAL REGISTRATION NUMBER

ChiCTR2200058680.

Healthy Lifestyle and Breast Cancer Risk in Palestinian Women: A Case-Control Study

The aim of this study was to investigate the association between a combined healthy lifestyle score and the risk of breast cancer (BC) in Palestinian women. A hospital-based case-control study compared 237 BC cases with confirmed diagnoses to 237 healthy controls. Women's lifestyle components were assessed using a validated questionnaire. A healthy lifestyle index (HLI) has been developed. We used logistic regression models to investigate the relationship between combined lifestyle scores and BC odds. The results revealed that HLI was significantly higher in the control group than in the study group. A higher HLI score was associated with a lower risk of BC in the multivariate analysis. The adjusted odds ratios (AOR) were 0.19 for all women, 0.15 for postmenopausal women, and 0.23 for premenopausal women when the HLI highest and lowest tertiles were compared. HLI score increases of one point resulted in a 41% reduction in the risk of BC for all women, a 42% reduction for postmenopausal and premenopausal women, and a 39% reduction for postmenopausal women. Women who live a healthy lifestyle, according to our findings, have a lower risk of breast cancer. BC prevention programs must promote long-term healthy food and lifestyle choices.

Association Between Genetic Risk, Adherence to Healthy Lifestyle Behavior, and Thyroid Cancer Risk

Importance

Genetic and lifestyle factors are related to thyroid cancer (TC). Whether a healthy lifestyle is associated with TC and could attenuate the influence of genetic variants in TC remains equivocal.

Objectives

To examine the associations between genetics and healthy lifestyle with incident TC and whether adherence to a healthy lifestyle modifies the association between genetic variants and TC.

Design, Setting, and Participants

A prospective cohort study using UK Biobank data recruited 502 505 participants aged 40 to 69 years between March 13, 2006, and October 1, 2010. A total of 307 803 participants of European descent were recruited at baseline, and 264 956 participants were available for the present study. Data analysis was conducted from November 1, 2021, to April 22, 2022.

Exposures

Lifestyle behaviors were determined by diet index, physical activity, weight, smoking, and alcohol consumption. Lifestyle was categorized as unfavorable (scores 0-1), intermediate (score 2), and favorable (scores 3-5). The polygenic risk score (PRS) was derived from a meta-genome-wide association study using 3 cohorts and categorized as low, intermediate, and high.

Main Outcomes and Measures

Thyroid cancer was defined using the International Classification of Diseases, Ninth Revision (code 193), International Statistical Classification of Diseases and Related Health Problems, Tenth Revision (code C73), and self-report (code 1065).

Results

Of 264 956 participants, 137 665 were women (52%). The median age was 57 (IQR, 49-62) years. During a median follow-up of 11.1 (IQR, 10.33-11.75) years (2 885 046 person-years), 423 incident TCs were ascertained (14.66 per 100 000 person-years). Higher PRSs were associated with TC (hazard ratio [HR], 2.25; 95% CI, 1.91-2.64; P = 8.65 × 10-23). An unfavorable lifestyle was also associated with a higher risk of TC (HR, 1.93; 95% CI, 1.50-2.49; P < .001). When stratified by PRS, unfavorable lifestyle was associated with TC in the higher PRS group (favorable vs unfavorable HR, 0.52; 95% CI, 0.37-0.73; P < .001). Furthermore, participants with both a high PRS and unfavorable lifestyle had the highest risk of TC (HR, 4.89; 95% CI, 3.03-7.91; P < .001).

Conclusions and Relevance

In this prospective cohort study, genetic and lifestyle factors were independently associated with incident TC, which suggests that a healthier lifestyle may attenuate the deleterious influence of genetics on the risk of TC in individuals of European descent.

Association of a Healthy Lifestyle Index with Risk of Breast Cancer among Women with Normal Body Mass Index in the UK Biobank

BACKGROUND

A high healthy lifestyle index (HLI), a composite score based on good diet quality, low alcohol consumption, no smoking, moderate to high physical activity, and waist circumference <80 cm, has been consistently associated with a reduced risk of breast cancer. Recently, high levels of body fat were found to be associated with an elevated risk of breast cancer in postmenopausal women with a normal body mass index (BMI; 18.5-<25 kg/m2). Whether the HLI is associated with breast cancer risk in women with normal BMI is unknown.

METHODS

We studied 102,572 women aged 40 to 69 years with a normal BMI at enrollment into the UK Biobank cohort study. The HLI was created by assigning to each component higher scores for healthier behaviors and then summing the scores. The HLI was categorized by tertiles and age- and multivariable-adjusted HRs for the association of the HLI with breast cancer risk by menopausal status were estimated using Cox proportional hazards models.

RESULTS

In postmenopausal women, compared with a low HLI, higher scores were associated with a reduced risk of breast cancer [HRHLI-3rd tertile = 0.76; 95% confidence interval (CI), 0.64-0.91]. Findings were similar for premenopausal women, although they did not reach statistical significance, except when smoking status was excluded from the HLI score (HLIwithout smoking: HR3rd tertile = 0.71; 95% CI, 0.56-0.90).

CONCLUSIONS

In normal BMI postmenopausal women, a high HLI score was associated with a reduced risk of breast cancer.

IMPACT

Following a healthy lifestyle may reduce the risk of breast cancer among normal weight postmenopausal women.

Association of a Combination of Healthy Lifestyle Behaviors With Reduced Risk of Incident Systemic Lupus Erythematosus

OBJECTIVE

While previous studies have demonstrated an association between individual factors related to lifestyle and the risk of systemic lupus erythematosus (SLE), it is unclear how the combination of these factors might affect the risk of incident SLE. This study was undertaken to prospectively evaluate whether a combination of healthy lifestyle factors is associated with a lower risk of incident SLE and its subtypes (anti-double-stranded DNA [anti-dsDNA]-positive and anti-dsDNA-negative SLE).

METHODS

The study included 185,962 women from the Nurses' Health Study (NHS) and NHSII cohorts, among whom there were 203 incident cases of SLE (96 with anti-dsDNA-positive SLE, 107 with anti-dsDNA-negative SLE) during 4,649,477 person-years of follow-up. The Healthy Lifestyle Index Score (HLIS) was calculated at baseline and approximately every 2 years during follow-up, with scores assigned for 5 healthy lifestyle factors: alcohol consumption, body mass index, smoking, diet, and exercise. A time-varying Cox proportional hazards regression model was used to estimate the adjusted hazard ratios (HRs) with 95% confidence intervals (95% CIs) for the risk of SLE. In addition, the percentage of partial population attributable risk (PAR%) of SLE development was calculated.

RESULTS

A higher HLIS was associated with a lower risk of SLE overall (HR 0.81 [95% CI 0.71-0.94]) and a lower risk of anti-dsDNA-positive SLE (HR 0.78 [95% CI 0.63-0.95]). Women with ≥4 healthy lifestyle factors had the lowest risk of SLE overall (HR 0.42, 95% CI 0.25-0.70) and lowest risk of anti-dsDNA-positive SLE (HR 0.35, 95% CI 0.17-0.75) as compared to women with only 1 healthy behavior or no healthy behaviors. The PAR% of SLE development was 47.7% (95% CI 23.1-66.6%), assuming that the entire population had adhered to at least 4 healthy lifestyle behaviors.

CONCLUSION

These results indicate that the risk of developing SLE, a disease in which significant evidence of genetic involvement has been established, might be reduced by nearly 50% with adherence to modifiable healthy lifestyle behaviors.

Supplemental Cancer Screening for Women With Dense Breasts: Guidance for Health Care Professionals

Mammography is the standard for breast cancer screening. The sensitivity of mammography in identifying breast cancer, however, is reduced for women with dense breasts. Thirty-eight states have passed laws requiring that all women be notified of breast tissue density results in their mammogram report. The notification includes a statement that differs by state, encouraging women to discuss supplemental screening options with their health care professionals (HCPs). Several supplemental screening tests are available for women with dense breast tissue, but no established guidelines exist to direct HCPs in their recommendation of preferred supplemental screening test. Tailored screening, which takes into consideration the patient's mammographic breast density and lifetime breast cancer risk, can guide breast cancer screening strategies that are more comprehensive. This review describes the benefits and limitations of the various available supplemental screening tests to guide HCPs and patients in choosing the appropriate breast cancer screening.

Identifying women with increased risk of breast cancer and implementing risk-reducing strategies and supplemental imaging

Breast cancer (BC) is the second most common cancer in women, affecting 1 in 8 women in the United States (12.5%) in their lifetime. However, some women have a higher lifetime risk of BC because of genetic and lifestyle factors, mammographic breast density, and reproductive and hormonal factors. Because BC risk is variable, screening and prevention strategies should be individualized after considering patient-specific risk factors. Thus, health care professionals need to be able to assess risk profiles, identify high-risk women, and individualize screening and prevention strategies through a shared decision-making process. In this article, we review the risk factors for BC, risk-assessment models that identify high-risk patients, and preventive medications and lifestyle modifications that may decrease risk. We also discuss the benefits and limitations of various supplemental screening methods.

Higher Healthy Lifestyle Score is associated with lower presence of non-alcoholic fatty liver disease in middle-aged and older Chinese adults: a community-based cross-sectional study

OBJECTIVE

Previous studies have reported inverse associations between certain healthy lifestyle factors and non-alcoholic fatty liver disease (NAFLD), but limited evidence showed the synergistic effect of those lifestyles. This study examined the relationship of a combination of lifestyles, expressed as Healthy Lifestyle Score (HLS), with NAFLD.

DESIGN

A community-based cross-sectional study. Questionnaires and body assessments were used to collect data on the six-item HLS (ranging from 0 to 6, where higher scores indicate better health). The HLS consists of non-smoking (no active or passive smoking), normal BMI (18·5-23·9 kg/m2), physical activity (moderate or vigorous physical activity ≥ 150 min/week), healthy diet pattern, good sleep (no insomnia or <6 months) and no anxiety (Self-rating Anxiety Scale < 50), one point each. NAFLD was diagnosed by ultrasonography.

SETTING

Guangzhou, China.

PARTICIPANTS

Two thousand nine hundred and eighty-one participants aged 40-75 years.

RESULTS

The overall prevalence of NAFLD was 50·8 %. After adjusting for potential covariates, HLS was associated with lower presence of NAFLD. The OR of NAFLD for subjects with higher HLS (3, 4, 5-6 v. 0-1 points) were 0·68 (95 % CI 0·51, 0·91), 0·58 (95 % CI 0·43, 0·78) and 0·35 (95 % CI 0·25, 0·51), respectively (P-values < 0·05). Among the six items, BMI and physical activity were the strongest contributors. Sensitivity analyses showed that the association was more significant after weighting the HLS. The beneficial association remained after excluding any one of the six components or replacing BMI with waist circumference.

CONCLUSIONS

Higher HLS was associated with lower presence of NAFLD, suggesting that a healthy lifestyle pattern might be beneficial to liver health.

Combined Lifestyle Behaviors and the Incidence of Common Cancer Types in the Norwegian Women and Cancer Study (NOWAC)

INTRODUCTION

Only a small number of studies have examined the impact of combined lifestyle behaviors on cancer incidence, and never in a Norwegian population.

PURPOSE

To examine linear and nonlinear associations of combined lifestyle factors, assessed through a healthy lifestyle index (HLI), with the incidence of postmenopausal breast, colorectal, lung, postmenopausal endometrial, postmenopausal ovarian, pancreatic, and kidney cancer among women in Norway.

METHODS

This prospective study included 96,869 women enrolled in the Norwegian Women and Cancer (NOWAC) cohort. Baseline information on lifestyle factors was collected between 1996 and 2004. The HLI was constructed from five lifestyle factors: physical activity level, body mass index, smoking, alcohol consumption, and diet. Each factor contributed 0 to 4 points to the HLI score, which ranged from 0 to 20, with higher scores representing a healthier lifestyle. Multiple imputation was used to handle missing data. Cox proportional hazard regression models were used to estimate hazard ratios (HR) and 95% confidence intervals (CI). Restricted cubic splines were used to examine nonlinearity in the associations.

RESULTS

The HRs for a one-point increment on the HLI score were 0.97 (95% CI: 0.96-0.98) for postmenopausal breast cancer, 0.98 (0.96-1.00) for colorectal cancer, 0.86 (0.84-0.87) for lung cancer, 0.93 (0.91-0.95) for postmenopausal endometrial cancer, 0.99 (0.96-1.02) for postmenopausal ovarian cancer, 0.92 (0.89-0.95) for pancreatic cancer, and 0.94 (0.91-0.97) for kidney cancer. Nonlinearity was observed for the inverse associations between HLI score and the incidence of lung cancer and postmenopausal breast cancer.

CONCLUSION

Based on our results, healthier lifestyle, as assessed by the HLI score, was associated with lower incidence of postmenopausal breast, colorectal, lung, postmenopausal endometrial, pancreatic, and kidney cancer among women, although the magnitude and linearity varied. Adoption of healthier lifestyle behaviors should be a public health priority to reduce the cancer burden among Norwegian women.

Diet quality, gut microbiota, and microRNAs associated with mild cognitive impairment in middle-aged and elderly Chinese population

BACKGROUND

Diet, the gut microbiota, and microRNAs (miRNAs) have been recognized as factors possibly influencing the pathogenesis of Alzheimer's disease. However, the combined role of diet, the gut microbiota, and miRNAs in mild cognitive impairment (MCI) has not been extensively investigated.

OBJECTIVES

To examine the associations among diet quality, the gut microbiota, miRNAs, and risks of MCI in middle-aged and elderly Chinese population.

METHODS

Participants were drawn from the Effects and Mechanism Investigation of Cholesterol and Oxysterol on Alzheimer's disease (EMCOA) study. We included 2239 participants who completed comprehensive cognitive tests and dietary surveys at baseline and follow-up. Chinese Dietary Guidelines Index 2018 (CDGI-2018), Energy-Adjusted Dietary Inflammatory Index (E-DII) and Healthy Lifestyle Score (HLS) values were calculated based on data from a standard questionnaire. Changes of gut microbiota and serum miRNA expression were detected in 75 MCI and 52 healthy participants. The receiver operating characteristic curve was performed based on a logistic regression model distinguishing patients with MCI from healthy controls.

RESULTS

Higher CDGI-2018 (RR, 0.75; 95% CI: 0.58-0.98) and HLS (RR, 0.54; 95% CI: 0.34-0.84) values and lower E-DII (RR, 1.46; 95% CI: 1.14-1.87) values were significantly associated with a lower risk of MCI. Lower microbial diversity and abundance of Faecalibacterium, unidentified Ruminococcaceae, and Alistipes were found in MCI participants compared with healthy controls. The abundance of ProteobacteriaandGammaproteobacteria was higher in MCI participants and was correlated with hsa-let-7g-5p, hsa-miR-107, and hsa-miR-186-3p. The predictive signatures of diet quality scores, differential gut microbiota, and serum miRNAs had good performance on distinguishing MCI participants from healthy individuals (AUC = 0.91).

CONCLUSIONS

A better diet quality is associated with a lower risk of MCI, which may be mediated by the microbiota composition and miRNA expression. These findings suggest that diet, the gut microbiota, and miRNAs may serve as a combinatorial biomarker to identify MCI patients and provide new insight for the diagnosis and prevention of MCI. This study was registered at the Chinese Clinical Trial Registry as ChiCTROOC-17011882.

Association Between Diet Quality and Risk of Ovarian and Endometrial Cancers: A Systematic Review of Epidemiological Studies

Objectives

The relationship between diet quality indices and risk of ovarian and endometrial cancers were unclear. We aimed at conducting a systematic review to evaluate the epidemiological evidence.

Methods

Embase, PubMed, Web of Science and Scopus databases were searched for eligible studies up to December 2020. Epidemiological studies reported the association of the diet quality with risk of ovarian and endometrial cancers were evaluated.

Results

Eleven eligible studies were identified, of which six studies were case-control studies, four were cohort studies, and one was case-cohort study. All studies were considered as high-quality with low risk of bias. Seven studies evaluated the association of diet quality with risk of ovarian cancer. Four studies reported null association for diet quality indices such as Healthy Eating Index (HEI)-2005, HEI-2010, Mediterranean Diet Score (MDS) and Recommended Foods Score (RFS). Two studies reported significantly inverse association for Alternate Healthy Eating Index (AHEI)-2010 and Healthy Diet Score (HDS) indices. One study reported significantly increased risk of ovarian cancer associated with higher level of Dietary Guidelines for Americans Index. Dose-response analysis showed pooled relative risks of 0.98 (95%Cl: 0.95, 1.01) and 0.94 (95%Cl: 0.77, 1.13) for each 10 points increase in the HEI-2005 and AHEI-2010 indices. Seven studies evaluated the association of diet quality with risk of endometrial cancer. Three studies reported significantly inverse association of diet quality as assessed by the MDS and Diet Score Quintiles with risk of endometrial cancer. Four studies reported null association for other diet quality indices including HEI-2005, HEI-2010, RFS and HDS. Dose-response analysis showed a pooled relative risk of 0.87 (95%CI: 0.81, 0.93) for one unit increment of the MDS.

Conclusion

This study suggests little evidence on the association between diet quality and risk of ovarian cancer. Adherence to high quality diet, as assessed by MDS, might be associated with lower the risk of endometrial cancer.

Competing Risks of Cancer and Non-Cancer Mortality When Accompanied by Lifestyle-Related Factors-A Prospective Cohort Study in Middle-Aged and Older Adults

Background

The study aimed to identify the association between the lifestyle-related factors and the cancer-specific, or non-cancer-specific mortality, when accompanied by a competing risk. Two statistical methods were applied, i.e., cause-specific hazard (CSH), and sub-distribution hazard ratio (SHR). Their respective key advantages, relative to the actual study design, were addressed, as was overall application potential.

Methods

Source data from 4,584 residents (34.2% men), aged 45–64 years, were processed using two different families of regression models, i.e., CSH and SHR; principal focus upon the impact of lifestyle-related factors on the competing risk of cancer and non-cancer mortality. The results were presented as hazard ratios (HR) with 95% confidence intervals (95% CI).

Results

Age, smoking status, and family history of cancer were found the leading risk factors for cancer death; the risk of non-cancer death higher in the elderly, and smoking individuals. Non-cancer mortality was strongly associated with obesity and hypertension. Moderate to vigorous physical activity decreased the risk of death caused by cancer and non-cancer causes.

Conclusions

Specific, lifestyle-related factors, instrumental in increasing overall, and cancer-specific mortality, are modifiable through health-promoting, individually pursued physical activities. Regular monitoring of such health-awareness boosting pursuits seems viable in terms of public health policy making.

Effects of major lifestyle factors on breast cancer risk: impact of weight, nutrition, physical activity, alcohol and tobacco

Breast cancer (BC) is the most commonly diagnosed cancer and second most common cause of cancer death in US women. Family history and genetics are well-known BC risk factors, but they only account for 15–20% of BC cases. Therefore, in addition to family history, healthcare providers must consider a woman’s modifiable and nonmodifiable personal risk factors that are associated with an increase in BC risk. The World Cancer Research Fund/American Institute for Cancer Research estimate that 30% of BC cases in the US are preventable. Lifestyle education is imperative given the magnitude of BC occurrence. Evidence supports prevention as an effective, long-term strategy for reducing risk. Healthcare providers are key stakeholders in empowering patients to adopt a healthy lifestyle for primary BC prevention. In this paper, we review the available evidence on modifiable BC risk including weight management, nutrition, physical activity, alcohol and tobacco use and provide strategies to counsel patients on lifestyle modifications.

Adherence to Cancer Prevention Guidelines and Endometrial Cancer Risk: Evidence from a Systematic Review and Dose-Response Meta-analysis of Prospective Studies

Purpose

The evidence of adherence to cancer prevention guidelines and endometrial cancer (EC) risk has been limited and controversial. This study summarizes and quantifies the relationship between adherence to cancer prevention guidelines and EC risk.

Materials and Methods

The online databases PubMed, Web of Science, and EMBASE were searched for relevant publications up to June 2, 2020. This study had been registered at PROSPERO. The registration number is CRD42020149966. Study quality evaluation was performed based on the Newcastle-Ottawa Scale. The I² statistic was used to estimate heterogeneity among studies. Egger’s and Begg’s tests assessed potential publication bias. Summary hazard ratios (HRs) and 95% confidence intervals (CIs) for the relationship between adherence to cancer prevention guidelines score was assigned to participants by summarizing individual scores for each lifestyle-related factor. The scores ranged from least healthy (0) to most healthy (20) and the EC risk was calculated using a random-effects model.

Results

Five prospective studies (four cohort studies and one case-cohort study) consisted of 4,470 EC cases, where 597,047 participants were included. Four studies had a low bias risk and one study had a high bias risk. Summary EC HR for the highest vs. lowest score of adherence to cancer prevention guidelines was 0.54 (95% CI, 0.40 to 0.73) and had a high heterogeneity (I²=86.1%). For the dose-response analysis, an increment of 1 significantly reduced the risk of EC by 6%. No significant publication bias was detected.

Conclusion

This study suggested that adherence to cancer prevention guidelines was negatively related to EC risk.

Genetic Factors, Adherence to Healthy Lifestyle Behavior, and Risk of Invasive Breast Cancer Among Women in the UK Biobank

BACKGROUND

Breast cancer is considered to result from a combination of genetic and lifestyle-related factors, but the degree to which an overall healthy lifestyle may attenuate the impact of multiple genetic variants on invasive breast cancer risk remains equivocal.

METHODS

Using Cox proportional hazards regression models, we examined the association of a modified healthy lifestyle index (HLI) with risk of invasive breast cancer by genetic risk group among 146 326 women from the UK Biobank. We generated an HLI score based on a combination of diet, physical activity, smoking, alcohol consumption and anthropometry, and a polygenic risk score (PRS) using 304 breast cancer-associated genetic loci.

RESULTS

Among premenopausal and postmenopausal women, a favorable lifestyle (highest tertile) was associated with 22% and 31% reductions in invasive breast cancer risk, respectively (hazard ratio [HR]high vs low = 0.78, 95% confidence interval [CI] = 0.64 to 0.94; HRhigh vs low = 0.69, 95% CI = 0.63 to 0.77, respectively), whereas a high PRS (highest tertile) was associated with more than a doubling in the risk in both groups. For premenopausal women, the greatest risk reduction in association with the HLI was seen among those with a high PRS (HRhigh vs low = 0.73, 95% CI = 0.75 to 0.95). In postmenopausal women, those with a favorable lifestyle had 30%, 29%, and 32% reductions in risk of invasive breast cancer in the low, intermediate, and high PRS groups, respectively (HRhigh vs low = 0.70, 95% CI = 0.56 to 0.88; HRhigh vs low = 0.71, 95% CI = 0.59 to 0.84; and HRhigh vs low = 0.68, 95% CI = 0.59 to 0.78, respectively). There was an additive but not multiplicative interaction between the HLI score and PRS for postmenopausal and, to a lesser extent, premenopausal women.

CONCLUSION

Our findings support the view that an overall healthy lifestyle may attenuate the impact of genetic factors on invasive breast cancer risk among women of European ancestry.

Higher healthy lifestyle scores are associated with greater bone mineral density in middle-aged and elderly Chinese adults

This study examined the association between healthy lifestyle score (HLS), which contained 7 items (smoking, BMI, physical activity, diet, alcohol, sleep and anxiety) and BMD. Results showed HLS was positively associated with BMD at all studied sites, suggesting that healthier lifestyle patterns might be beneficial to bone health.

PURPOSE

Previous studies have reported favourable associations of individual healthy lifestyle factors with bone mineral density (BMD), but limited evidence showed the relationship of a combined healthy lifestyle score (HLS) with BMD. This study examined the association between the HLS and BMD.

METHODS

This community-based cross-sectional study included 3051 participants aged 40-75 years. The HLS contained 7 items (smoking, BMI, physical activity, diet quality, alcohol intake, sleep and anxiety). BMD values of whole body (WB), lumbar spine 1-4 (L_1-4), total hip (TH) and femur neck (FN) were measured using dual-energy X-ray absorptiometry.

RESULTS

After adjusting for potential covariates, HLS was positively associated with BMD at all studied sites (P-trend < 0.01). The mean BMDs were 2.69% (WB), 5.62% (L_1-4), 6.13% (TH) and 5.71% (FN) higher in participants with HLS of 6-7 points than in those with HLS of 0-2 points. The per 1 of 7 unit increase in the HLS was associated with increases of 7.63 (WB)-13.4 (TH) mg/cm² BMD levels at all sites. These favourable associations tended to be more pronounced in men than in women. Among the 7 items, physical activity contributed most to the favourable associations, followed by BMI, non-smoking and diet; the other three items played little roles. Sensitivity analyses showed that the significant associations remained after excluding any one of the 7 components or excluding fracture subjects at all sites.

CONCLUSION

Higher HLS was associated with greater BMD in middle-aged and elderly Chinese, suggesting that healthier lifestyle patterns might be beneficial to bone health.

Co-consumption of Vegetables and Fruit, Whole Grains, and Fiber Reduces the Cancer Risk of Red and Processed Meat in a Large Prospective Cohort of Adults from Alberta's Tomorrow Project

We examined whether co-consumption of red and processed meat with key foods items and food constituents recommended for cancer prevention (vegetables and fruit, whole grains, and fiber) mitigates cancer incidence. In a prospective cohort of 26,218 adults aged 35–69 years at baseline, dietary intake was collected through 124-item past-year food frequency questionnaire. Incidence of all-cause and 15 cancers previously linked to red and processed meat intake was obtained through data linkage with a cancer registry (average follow-up 13.5 years). Competing risk Cox Proportional Hazard models estimated cancer risk and Accelerated Failure Time models estimated time-to-cancer occurrence for different combinations of intake levels while considering mortality from vital statistics and established confounders. Co-consumption of low vegetables and fruit intake with high processed meat was associated with higher incidence of all-cause and 15 cancers (men: HR = 1.85, 1.91; women: HR = 1.44, 1.49) and accelerated time-to-cancer occurrence (men: 6.5 and 7.1 years and women: 5.6 and 6.3 years, respectively), compared to high vegetables and fruit with low processed meat intake. Less pronounced and less consistent associations were observed for whole grains and fiber and for red meat. The findings provide initial evidence toward refining existing cancer prevention recommendations to optimize the intake and combination of foods in the general adult population.

Association between dietary intake and risk of ovarian cancer: a systematic review and meta-analysis

PURPOSE

It is unclear how dietary intake influences the ovarian cancer. The present paper sets out to systematically review and meta-analyze research on dietary intake to identify cases having high- or low-risk ovarian cancer.

METHODS

Scopus, PubMed, and Wiley Online Libraries were searched up to the date November 24, 2019. Two reviewers were requested to independently extract study characteristics and to assess the bias and applicability risks with reference to the study inclusion criteria. Meta-analyses were performed to specify the relationship between dietary intake and the risk of ovarian cancer identifying 97 cohort studies.

RESULTS

No significant association was found between dietary intake and risk of ovarian cancer. The results of subgroup analyses indicated that green leafy vegetables (RR = 0.91, 95%, 0.85-0.98), allium vegetables (RR = 0.79, 95% CI 0.64-0.96), fiber (RR = 0.89, 95% CI 0.81-0.98), flavonoids (RR = 0.83, 95% CI 0.78-0.89) and green tea (RR = 0.61, 95% CI 0.49-0.76) intake could significantly reduce ovarian cancer risk. Total fat (RR = 1.10, 95% CI 1.02-1.18), saturated fat (RR = 1.11, 95% CI 1.01-1.22), saturated fatty acid (RR = 1.19, 95% CI 1.04-1.36), cholesterol (RR = 1.13, 95% CI 1.04-1.22) and retinol (RR = 1.14, 95% CI 1.00-1.30) intake could significantly increase ovarian cancer risk. In addition, acrylamide, nitrate, water disinfectants and polychlorinated biphenyls were significantly associated with an increased risk of ovarian cancer.

CONCLUSION

These results could support recommendations to green leafy vegetables, allium vegetables, fiber, flavonoids and green tea intake for ovarian cancer prevention.

DNA Methylation in RARβ Gene as a Mediator of the Association Between Healthy Lifestyle and Breast Cancer: A Case-Control Study

Purpose

Lifestyle factors and methylation in the retinoic acid receptor β (RARβ) gene are associated with breast cancer (BC). This study aims to examine the mediation effect of RARβ methylation on the association between healthy lifestyle and BC in Chinese women.

Patients and Methods

This case–control study consisted of 408 BC patients and 573 controls. A healthy lifestyle score (HLS) was constructed based on diet, alcohol use, physical activity, body mass index and smoking. The mediation effect of RARβ methylation in peripheral blood leukocytes was assessed in a causal mediation model using R package Lavaan.

Results

A higher HLS was significantly associated with lower risk of BC (P-value<0.001). In mediation analyses, the total effect of HLS on BC measured as a regression coefficient was significant (−0.237). The indirect effects of HLS on RARβ methylation (−0.153) and RARβ methylation on BC (0.220) were both significant. The significant mediation effect of RARβ methylation on the HLS-BC association was estimated at 14.3%.

Conclusion

The relationship between healthy lifestyle and BC is partly mediated by RARβ methylation, suggesting that epigenetic modifications play a role in the underlying mechanisms in response to lifestyles and contribute to the development of BC.

Exploring the effects of lifestyle on breast cancer risk, age at diagnosis, and survival: the EBBA-Life study

Purpose

Whether an unfavorable lifestyle not only affects breast cancer risk, but also influences age at onset of breast cancer and survival, is under debate.

Methods

In a population-based cohort, the Energy Balance and Breast Cancer Aspects throughout life (EBBA-Life) study, a total of 17,145 women were included. During follow-up, 574 women developed invasive breast cancer. Breast cancer cases were followed for an additional 9.1 years. Detailed medical records were obtained. Cox’s proportional hazard regression models were used to study the association between pre-diagnostic lifestyle factors (weight, physical activity, alcohol use, smoking, and hypertension), breast cancer risk, age at diagnosis, and survival.

Results

At study entry, 34.3% of the participating women were overweight and 30.7% were physically inactive. Mean age at breast cancer diagnosis was 58.0 years, and 78.9% of the tumors were estrogen receptor positive. Among menopausal women who did not use hormone therapy and had an unfavorable lifestyle (3–5 unfavorable factors), compared with women who had a favorable lifestyle, we observed a twofold higher risk for postmenopausal breast cancer (hazard ratio [HR] 2.13, 95% confidence interval [CI] 1.23–3.69), and they were 3.4 years younger at diagnosis (64.8 versus 68.2 years, P = 0.032). Breast cancer patients with an unfavorable lifestyle, compared with patients with a favorable lifestyle, had almost a two times higher overall mortality risk (HR 1.96, 95% CI 1.01–3.80).

Conclusions

Our study supports a healthy lifestyle improving breast cancer prevention, postponing onset of disease, and extending life expectancy among breast cancer patients.

Electronic supplementary material

The online version of this article (10.1007/s10549-020-05679-2) contains supplementary material, which is available to authorized users.

Association between healthy lifestyle score and breast cancer

BACKGROUND

Majority of earlier studies have assessed the association between individual lifestyle factors and the risk of breast cancer (BC); however, limited information is available linking the whole lifestyle factors to BC. We aimed to examine the association between combined lifestyle score (diet, physical activity (PA) and smoking) and risk of BC in Iranian population.

METHODS

This population-based case-control study included 350 newly diagnosed cases of BC and 700 healthy controls randomly selected from adult women. Dietary intakes, PA and smoking status of study participants were examined using validated questionnaires. The lifestyle risk factors examined in this study included cigarette smoking, physical inactivity, and Healthy Eating Index-2010 (HEI-2010). The lifestyle score ranged from zero (non-healthy) to 3 (most healthy) points. Logistic regression models were fitted to investigate the association between combined lifestyle scores and odds of BC.

RESULTS

Mean age and body mass index (BMI) of study participants were 62.4 years and 24.3 kg/m², respectively. In the whole study population, individuals with the highest healthy lifestyle score (HLS) were 0.38 times less likely to have BC than those with the lowest score (OR: 0.62; 95% CI: 0.40, 0.93, P_trend = 0.01). The analysis by menopausal status showed that postmenopausal women with the highest HLS had 44% lower odds of BC compared with those with the lowest score (OR: 0.56; 95% CI: 0.36, 0.88, P _trend = 0.004). Such association was not seen in premenopausal women. After analyzing each component of HLS, we found that individuals with the highest HEI score were 46% less likely to have BC than those with the lowest score (OR: 0.54; 95% CI: 0.35, 0.82, P_trend <  0.001). No other significant associations were found between PA and smoking and risk of BC.

CONCLUSIONS

Significant inverse associations were found between HLS and HEI with BC especially among postmenopausal women. Prospective studies are required to confirm these findings.

Endometrial cancer prevention in high-risk women

Endometrial cancer (EC) is the most common gynaecological malignancy, and its incidence is rising alongside the growing prevalence of obesity. Effective risk-reducing interventions hijacking the key mechanisms driving endometrial carcinogenesis may affect EC diagnoses if aimed at those at greatest risk. An understanding of the key risk factors and their role in tumourigenesis is critical in developing such prevention strategies. In this review, we summarise the major risk factors for EC and the evidence for available risk-reducing interventions in high-risk women. We suggest potential prevention strategies and make a case for the need for risk prediction models that identify specific groups of women at a particularly high risk of EC for whom risk-reducing interventions are likely to have a significant impact.

Joint tobacco smoking and alcohol intake exacerbates cancer risk in women- the Danish nurse cohort

PURPOSE

To explore separate and combined tobacco and alcohol use and risk of overall, smoking-related, alcohol-related, breast and gynecological cancers in women.

METHOD

Questionnaires from 19,898 women in The Danish Nurse Cohort in 1993 were linked to registries on hospitalizations, death causes and migration until Dec 2016. Cancer risk by tobacco and alcohol was estimated using Cox proportional hazards models.

RESULTS

16,106 nurses, aged >44 years (mean = 56), were eligible for analysis. Throughout 23 years (mean follow-up = 18.8 years) overall cancers counted 4,968. Of these, 1,897, 2,231, 1,407 and 579 events were smoking-related, alcohol-related, breast cancers and gynecological cancers. Increased risks of overall, smoking-related, and breast cancer were observed for current smoking and excess alcohol intake (>14 units/week), separately, compared to never smoking and light drinking (1-7 units/week) respectively. Moderate drinking (8-14 units/week) increased the risk of alcohol-related and breast cancer. Additional risk increases were observed among smokers drinking alcohol above light levels for overall, smoking-related, alcohol-related and breast cancer (HR = 1.40, 95% CI:1.30-1.51, HR = 1.72, 95% CI:1.52-1.94, HR = 1.33, 95% CI:1.26-1.40, HR = 1.32, 95% CI:1.15-1.53, respectively), compared to non-smokers drinking lightly. These risks increased further for smokers drinking above moderate levels (HR = 1.49, 95% CI:1.36-1.63, HR = 1.97, 95% CI:171.-2.26, HR = 1.40, 95% CI:1.22-1.60, HR = 1.33, 95% CI:1.12-1.57, respectively). No significant associations were found for gynecological cancer.

CONCLUSIONS

Smoking and alcohol, both separately and combined, increased risks of overall, smoking-related, alcohol-related and breast cancer; combined use resulted in incremental risk increases. Co-use of smoking and alcohol represent an extensive threat to public health; thus, prevention could benefit from combined targeting.

Healthy lifestyle and the risk of pancreatic cancer in the EPIC study

 = 4.9e-04). The overall PAF estimate was 19% (95% CI: 11%, 26%), and 14% (6%, 21%) when smoking was removed from the score. Adherence to a healthy lifestyle was inversely associated with PC risk, beyond the beneficial role of smoking avoidance. Public health measures targeting compliance with healthy lifestyles may have an impact on PC incidence.

Time trends in healthy lifestyle among adults in Germany: Results from three national health interview and examination surveys between 1990 and 2011

BACKGROUND

The combined impact of multiple healthy behaviors on health exceeds that of single behaviors. This study aimed to estimate trends in the prevalence of a healthy lifestyle among adults in Germany.

METHODS

A data set of 18,058 adults aged 25-69 years from three population-based national health examination surveys 1990-92, 1997-99 and 2008-11 with complete information for five healthy behavior factors was used. A 'daily intake of both fruits and vegetables, 'sufficient physical exercise', 'no current smoking' and 'no current risk drinking' were assessed with self-reports and 'normal body weight' was calculated based on measured body weight and height. A dichotomous 'healthy lifestyle' indicator was defined as meeting at least four out of five healthy behaviors. Age-standardized prevalence was calculated stratified by sex, age groups (25-34, 35-44, 45-54 and 55-69 years) and education level (low, medium and high). Trends were expressed in relative change (RC) between 1990-92 and 2008-11.

RESULTS

In Germany, the overall prevalence of healthy lifestyle increased from 9.3% in 1990-92 to 13.5% in 1997-99 and to 14.7% in 2008-11 (RC: +58.1%). The prevalence increased among men and women and in all age groups, with the exception of men aged 45-54 years. The RC of increasing healthy lifestyle prevalence between 1990-92 and 2008-11 was stronger albeit on a higher level among women compared to men. Therefore, the gender difference in healthy lifestyle has increased, but age-related differences have overall decreased in this period. Among high educated men the prevalence of a healthy lifestyle increased between 1990-92 and 2008-11 from 10.6% to 16.3% (p = 0.01) and among high educated women from 16.4% to 30.3% and also among medium educated women (10.9 to 16.6, p<0.01), but no significant increase in healthy lifestyle prevalence was observed among men with low and medium education and among women with low education level.

CONCLUSIONS

The prevalence of a lifestyle with at least four out of five healthy behaviors markedly increased from 1990-92 to 2008-11. Nevertheless, additional health promotion interventions are needed to improve the number of combined healthy behavior factors and the awareness in the population that each additional healthy behavior factor leads to a further improvement in health, especially in men in the age-range 45 to 54 years, and among persons with low education level.

Healthy lifestyle and breast cancer risk: A case-control study in Morocco

BACKGROUND

Some modifiable risk factors have been independently associated with breast cancer (BC) risk in Moroccan women, but no studies have investigated their joint association. This study aimed to investigate the association between a Healthy Lifestyle Index (HLI) score and BC risk among Moroccan women.

METHODS

In this case-control study, 300 incident BC cases and 300 controls, matched by age and area of residence were recruited. Cases were women newly-diagnosed with histopathologically-confirmed BC at the University Hospital in Fez, Morocco. Controls were randomly selected healthy women recruited from 6 primary health centers in Fez. HLI scores developed within this study were assigned to participants based on 11 factors (red and processed meat, white meat, cream, cheese, fish, fruit and vegetables, physical activity, BMI, smoking, alcohol consumption, and breastfeeding), where 0 was given to unhealthy and 0.5 or 1 to healthy levels of each factor. Conditional and unconditional logistic regression models were used to assess the association between HLI scores and BC risk.

RESULTS

Mean of HLI scores were 8.1 (±1.1) and 9.0 (±0.9) in cases and controls, respectively, p < 0.01. After adjusting for potential confounders, one-point increment in the HLI score was associated with 56% (95% CI, CI: 39-68%), 49% (95% CI: 30-63%), and 59% (95% CI: 40-72%) lower risks of BC in all, premenopausal, and postmenopausal women, respectively.

CONCLUSION

High HLI scores were associated with decreased risk of BC in Moroccan women. These findings suggest that BC prevention policies should include strategies for engaging Moroccan women in healthy lifestyles.

Prevention Strategies in Endometrial Carcinoma

PURPOSE OF THE REVIEW

To assess the most recent high-quality evidence for endometrial cancer prevention strategies.

RECENT FINDINGS

Obesity is an established risk factor for endometrial cancer. Weight cycling and weight gain in middle age are risk factors for endometrial cancer. Bariatric surgery reduces the risk of endometrial cancer by up to 81% in obese women who attain and maintain a normal weight. Combined oral contraceptives provide durable protection against endometrial cancer for 30 years or more. Ever use of the levonorgestrel intrauterine system (LNG-IUS) and inert intrauterine devices reduce endometrial cancer risk. The first oestrogen-based non-progestin HRT for non-hysterectomised women that contains estradiol and bazedoxifene has an effective protective effect on endometrium. Bisphosphonates reduce endometrial cancer risk. Weight loss and LNG-IUS would seem to be an effective strategy for preventing the development of obesity-driven endometrial cancer in the highest risk women. Future research may identify other safe and effective chemoprevention interventions, such as aspirin, bisphosphonates or metformin.