A prospective study of age-specific physical activity and premenopausal breast cancer

Recreational physical activity and breast cancer risk by menopausal status and tumor hormone receptor status: results from the Nurses' Health Studies

PURPOSE

Physical activity is associated with lower breast cancer risk, especially in postmenopausal women. Associations in premenopausal women are less well established.

METHODS

We evaluated recreational physical activity and breast cancer risk in the Nurses' Health Study (NHS) and NHSII (187,278 women; n = 12,785 breast cancers; follow-up: NHS = 1986-2016, NHSII = 1989-2017) by menopausal status and estrogen (ER) and progesterone (PR) receptor status. Physical activity was evaluated as updated cumulative average of metabolic equivalent of task (MET)-h/week. Cox proportional hazards models were used to estimate multivariable hazard ratios (HR) and 95% confidence intervals (CI).

RESULTS

Recreational physical activity was inversely associated with breast cancer risk in pre- and postmenopausal women. Higher activity levels were associated with lower risk of ER+/PR + breast cancer in both pre- and postmenopausal women (e.g., total recreational activity, ≥ 27 vs < 3 MET-h/week, premenopausal HR = 0.83, 95%CI = (0.70-0.99), postmenopausal HR = 0.86 (0.78-0.95); pheterogeneity = 0.97). Results were attenuated with adjustment for current body mass index (BMI) among postmenopausal, but not premenopausal, women (e.g., ≥ 27 vs < 3 MET-h/week, premenopausal HR = 0.83 (0.69-0.98); postmenopausal HR = 0.95 (0.85-1.05); pheterogeneity = 0.99). In analyses of moderate-vigorous activity and breast cancer risk, no heterogeneity by menopausal status was observed (phet ≥ 0.53; e.g., ≥ 27 vs < 3 MET-h/week, ER+/PR+, premenopausal HR = 0.88 (0.69-1.11); postmenopausal HR = 0.71 (0.58-0.88). No associations were observed for ER-/PR- disease.

CONCLUSIONS

Recreational physical activity was associated with lower breast cancer risk in both pre- and postmenopausal women, supporting recreational physical activity as an accessible, modifiable exposure associated with reduced breast cancer risk regardless of menopausal status.

Non-occupational physical activity and risk of cardiovascular disease, cancer and mortality outcomes: a dose-response meta-analysis of large prospective studies

OBJECTIVE

To estimate the dose-response associations between non-occupational physical activity and several chronic disease and mortality outcomes in the general adult population.

DESIGN

Systematic review and cohort-level dose-response meta-analysis.

DATA SOURCES

PubMed, Scopus, Web of Science and reference lists of published studies.

ELIGIBILITY CRITERIA

Prospective cohort studies with (1) general population samples >10 000 adults, (2) ≥3 physical activity categories, and (3) risk measures and CIs for all-cause mortality or incident total cardiovascular disease, coronary heart disease, stroke, heart failure, total cancer and site-specific cancers (head and neck, myeloid leukaemia, myeloma, gastric cardia, lung, liver, endometrium, colon, breast, bladder, rectum, oesophagus, prostate, kidney).

RESULTS

196 articles were included, covering 94 cohorts with >30 million participants. The evidence base was largest for all-cause mortality (50 separate results; 163 415 543 person-years, 811 616 events), and incidence of cardiovascular disease (37 results; 28 884 209 person-years, 74 757 events) and cancer (31 results; 35 500 867 person-years, 185 870 events). In general, higher activity levels were associated with lower risk of all outcomes. Differences in risk were greater between 0 and 8.75 marginal metabolic equivalent of task-hours per week (mMET-hours/week) (equivalent to the recommended 150 min/week of moderate-to-vigorous aerobic physical activity), with smaller marginal differences in risk above this level to 17.5 mMET-hours/week, beyond which additional differences were small and uncertain. Associations were stronger for all-cause (relative risk (RR) at 8.75 mMET-hours/week: 0.69, 95% CI 0.65 to 0.73) and cardiovascular disease (RR at 8.75 mMET-hours/week: 0.71, 95% CI 0.66 to 0.77) mortality than for cancer mortality (RR at 8.75 mMET-hours/week: 0.85, 95% CI 0.81 to 0.89). If all insufficiently active individuals had achieved 8.75 mMET-hours/week, 15.7% (95% CI 13.1 to 18.2) of all premature deaths would have been averted.

CONCLUSIONS

Inverse non-linear dose-response associations suggest substantial protection against a range of chronic disease outcomes from small increases in non-occupational physical activity in inactive adults. PROSPERO registration number CRD42018095481.

"I haven't had that information, even though I think I'm really well-informed about most things": a qualitative focus group study on Australian women's understanding and views of potentially modifiable risk factors for breast cancer

BACKGROUND

Building health literacy about potentially modifiable risk factors for breast cancer may help to empower women to make more informed decisions about their breast health; however there has been limited qualitative research on this topic. This study aimed to explore current knowledge, understanding and experience of potentially modifiable risk factors for breast cancer, and views on current and future communication strategies for this information and related interventions.

METHODS

Qualitative study using online focus groups via Zoom in October-November 2022. A diverse sample of women from the Australian community aged 40-74 years were recruited.

RESULTS

Fifty-one women from a range of socioeconomic backgrounds took part in nine focus groups. General knowledge of risk factors for breast cancer in the community is limited, particularly in relation to modifiable factors such as alcohol consumption and postmenopausal obesity, with many women describing feelings of 'shock' following this information. Women overwhelming believed that information on modifiable risk factors for breast cancer should be communicated more widely, however communication preferences for receiving this information varied. There was a strong preference amongst the women for a cascade of information which they believed may then help target greater number of women of all ages and backgrounds. Despite worry about long-term compliance, women also supported various lifestyle interventions which may help them and other women to reduce their overall risk.

CONCLUSIONS

Findings from this study highlight the need for more widespread community communication and education about risk factors for breast, in particular potentially modifiable risk factors such as alcohol consumption and postmenopausal obesity. As breast screening programs in Australia and globally begin to evaluate the potential for risk-related screening this will provide an additional context for primary prevention, hence planning of messaging and piloting of lifestyle-related prevention strategies in breast cancer is needed now. Gaining an understanding of women's preferences for communication and forms of interventions is vital to ensure their engagement.

Investigating the Link between Early Life and Breast Anomalies

Several factors during childhood and adolescence are thought to be associated with the development of proliferative benign breast diseases and breast cancer in adulthood. In order to identify them, the authors conducted an extensive review of the literature up to October 2022, searching for clinical studies, reports, and guidelines in English. A thorough Medline/Pubmed and Google scholar database research was performed, investigating the link between diet, exercise, age of menarche, body mass index, ionizing radiation exposure during childhood and adolescence, and proliferative breast diseases and breast cancer in adulthood. A list of keywords, including breast disorders, adolescence, childhood, and breast cancer was included in our search algorithm. Numerous studies concede that the development of breast disease in adulthood is influenced by various risk factors, whose influence begins during early childhood and adolescence.

Physical activity from menarche-to-first pregnancy and risk of breast cancer: the California teachers study

PURPOSE

A longer menarche-to-first pregnancy window of susceptibility (WOS) is associated with increased breast cancer risk. Whether physical activity, an established preventive risk factor, during the menarche-to-first pregnancy WOS offsets breast cancer risk overall or for specific molecular subtypes is unclear.

METHODS

We examined the prospective association between physical activity during the menarche-to-first pregnancy WOS and breast cancer risk in the California Teachers Study (N = 78,940). Recreational physical activity at multiple timepoints were recalled at cohort entry, and converted to metabolic equivalent of task hours per week (MET-hrs/wk). We used multivariable Cox proportional hazards models to estimate hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

We observed 5,157 invasive breast cancer cases over 21.6 years of follow-up. Longer menarche-to-first pregnancy WOS (≥ 20 vs. < 15 years) was associated with higher breast cancer risk (HR = 1.23, 95% CI = 1.13-1.34). Women with higher physical activity level during menarche-to-first pregnancy had lower risk of invasive breast cancer (≥ 40 vs. < 9 MET-hrs/wk: HR = 0.89, 95% CI = 0.83-0.97) and triple-negative subtype (≥ 40 vs. < 9 MET-hrs/wk: HR = 0.53, 95% CI = 0.32-0.87). No association was observed for luminal A-like and luminal B-like subtypes. Higher physical activity level was associated with lower breast cancer risk among women with moderate (15-19 years) menarche-to-first pregnancy intervals (≥ 40 vs. < 9 MET-hrs/wk: HR = 0.80, 95% CI = 0.69-0.92), but not with short (< 15 years) or long (≥ 20 years) intervals.

CONCLUSION

Physical activity during a WOS was associated with lower breast cancer risk in our cohort. Understanding timing of physical activity throughout the life course in relationship with breast cancer risk maybe important for cancer prevention strategies.

Cancer Risk Reduction Through Education of Adolescents: Development of a Tailored Cancer Risk-Reduction Educational Tool

Growing evidence links adolescent exposures to cancer risk later in life, particularly for common cancers like breast. The adolescent time period is also important for cancer risk reduction as many individual lifestyle behaviors are initiated including smoking and alcohol use. We developed a cancer risk-reduction educational tool tailored for adolescents that focused on five modifiable cancer risk factors. To contextualize risk factors in adolescents' social and physical environments, the intervention also focused on structural barriers to individual- and community-level change, with an emphasis on environmental justice or the fair treatment and meaningful involvement of all people regardless of race, color, national origin, or income with respect to the development, implementation, and enforcement of environmental laws, regulations, and policies. The educational tool consisted of a 50-min module that included an introduction to cancer biology including genetic susceptibility and environmental interactions, cancer burden in the local community, and risk reduction strategies. The module also included an interactive activity in which adolescent students identify cancer risk factors and brainstorm strategies for risk reduction at both the individual and community level. We administered the module to 12 classes of over 280 high school and college students in New York City. Cancer risk reduction strategies identified by the students included family- or peer-level strategies such as team physical activity and community-level action including improving parks and taxing sugary foods. We developed a novel and interactive cancer risk-reduction education tool focused on multiple cancers that can be adopted by other communities and educational institutions.

Cellular and molecular mechanisms of breast cancer susceptibility

There is a plethora of recognized risk factors for breast cancer (BC) with poorly understood or speculative biological mechanisms. The lack of prevention options highlights the importance of understanding the mechanistic basis of cancer susceptibility and finding new targets for breast cancer prevention. Until now, we have understood risk and cancer susceptibility primarily through the application of epidemiology and assessing outcomes in large human cohorts. Relative risks are assigned to various human behaviors and conditions, but in general the associations are weak and there is little understanding of mechanism. Aging is by far the greatest risk factor for BC, and there are specific forms of inherited genetic risk that are well-understood to cause BC. We propose that bringing focus to the biology underlying these forms of risk will illuminate biological mechanisms of BC susceptibility.

A Review of Breast Cancer Risk Factors in Adolescents and Young Adults

Simple Summary

Cancer diagnosed in patients between the ages of 15 and 39 deserves special consideration. Diagnoses within this cohort of adolescents and young adults include childhood cancers which present at an older age than expected, or an early presentation of cancers that are typically observed in older adults, such as breast cancer. Cancers within this age group are associated with worse disease-free and overall survival rates, and the incidence of these cases are rising. Knowing an individual’s susceptibility to disease can change their clinical management and allow for the risk-testing of relatives. This review discusses the risk factors that contribute to breast cancer in this unique cohort of patients, including inherited genetic risk factors, as well as environmental and lifestyle factors. We also describe risk models that allow clinicians to quantify a patient’s lifetime risk of developing disease.

Abstract

Cancer in adolescents and young adults (AYAs) deserves special consideration for several reasons. AYA cancers encompass paediatric malignancies that present at an older age than expected, or early-onset of cancers that are typically observed in adults. However, disease diagnosed in the AYA population is distinct to those same cancers which are diagnosed in a paediatric or older adult setting. Worse disease-free and overall survival outcomes are observed in the AYA setting, and the incidence of AYA cancers is increasing. Knowledge of an individual’s underlying cancer predisposition can influence their clinical care and may facilitate early tumour surveillance strategies and cascade testing of at-risk relatives. This information can further influence reproductive decision making. In this review we discuss the risk factors contributing to AYA breast cancer, such as heritable predisposition, environmental, and lifestyle factors. We also describe a number of risk models which incorporate genetic factors that aid clinicians in quantifying an individual’s lifetime risk of disease.

Tinnitus and 3-Year Change in Audiometric Hearing Thresholds

OBJECTIVES

Tinnitus and hearing loss commonly coexist, however, the temporal relation between tinnitus and hearing loss is complex and not fully understood. Our objective was to examine the longitudinal association between persistent tinnitus, bothersome tinnitus, and 3-year elevation of audiometric hearing thresholds.

DESIGN

We conducted a longitudinal cohort study among 3106 women (mean age 59 years) who were participants in the Nurses' Health Study II (2012-2018). Information on tinnitus was obtained from biennial questionnaires. Longitudinal changes in air conduction thresholds (0.5 to 8 kHz) were assessed by pure-tone audiometry conducted by licensed audiologists at 19 audiology testing sites across the United States. Logistic regression was used to estimate multivariable-adjusted odds ratios (MVORs, 95% confidence interval [CI]) and evaluate the relations of persistent tinnitus (several days per week or more), bothersome tinnitus (interferes with work, sleep, or daily activities), and risk of 3-year elevation of hearing thresholds.

RESULTS

Persistent tinnitus was associated with higher risk of 3-year elevation of hearing thresholds across a broad range of frequencies. Compared with women without tinnitus, the MVORs (95% CI) for ≥5-dB threshold elevation among women with persistent tinnitus were 1.01 (0.81, 1.25) at 0.5 kHz, 1.45 (1.17, 1.81) at 1 kHz, 1.25 (1.00, 1.56) at 2 kHz, 1.34 (1.07, 1.69) at 3 kHz, 1.34 (1.06, 1.70) at 4 kHz, 1.49 (1.16, 1.91) at 6 kHz, and 1.63 (1.25, 2.12) at 8 kHz. The magnitudes of the associations for ≥10-dB threshold elevation were similar. The magnitudes of the associations were substantially greater among women with bothersome tinnitus. For example, compared with women without tinnitus, the MVORs (95% CI) for a ≥5- and ≥10-dB elevation of hearing thresholds at 4 kHz were 2.97 (1.50, 5.89) and 2.79 (1.38, 5.65), respectively. The risk was elevated even among women with tinnitus who had clinically normal hearing thresholds at baseline. In analyses that examined the association of tinnitus and elevation of low-, mid- and high-frequency pure-tone average (PTA) hearing thresholds, the results were similar. Compared with women without tinnitus, the MVORs (95% CI) for ≥5-dB PTA elevation among women with persistent tinnitus were 1.29 (0.99,1.67) for LPTA(0.5,1,2 kHz); 1.44 (1.16, 1.78) for MPTA(3,4 kHz); and 1.38 (1.11, 1.71) for HPTA(6,8 kHz). For ≥10-dB elevation, the MVORs were 2.85 (1.55, 5.23), 1.52 (1.10, 2.09), and 1.41 (1.10, 1.82), respectively.

CONCLUSION

Persistent tinnitus was associated with substantially higher risk of 3-year hearing threshold elevation, even among women with clinically normal baseline hearing. The magnitudes of the associations were greater among those with bothersome tinnitus. Monitoring hearing sensitivities may be indicated in patients with tinnitus, including those without audiometric evidence of hearing impairment.

Simple Sugar and Sugar-Sweetened Beverage Intake During Adolescence and Risk of Colorectal Cancer Precursors

BACKGROUND & AIMS

Recent increasing trends in early-onset colorectal cancer (CRC) strongly supports that early-life diet is involved in CRC development. However, data are lacking on the relationship with high sugar intake during early life.

METHODS

We prospectively investigated the association of adolescent simple sugar (fructose, glucose, added sugar, total sugar) and sugar-sweetened beverage (SSB) intake with CRC precursor risk in 33,106 participants of the Nurses' Health Study II who provided adolescent dietary information in 1998 and subsequently underwent lower gastrointestinal endoscopy between 1999 and 2015. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using logistic regression for clustered data.

RESULTS

During follow-up, 2909 conventional adenomas (758 high-risk) and 2355 serrated lesions were identified (mean age at diagnoses, 52.2 ± 4.3 years). High sugar and SSB intake during adolescence was positively associated with risk of adenoma, but not serrated lesions. Per each increment of 5% of calories from total fructose intake, multivariable ORs were 1.17 (95% CI, 1.05-1.31) for total and 1.30 (95% CI, 1.06-1.60) for high-risk adenoma. By subsite, ORs were 1.12 (95% CI, 0.96-1.30) for proximal, 1.24 (95% CI, 1.05-1.47) for distal, and 1.43 (95% CI, 1.10-1.86) for rectal adenoma. Per 1 serving/day increment in SSB intake, ORs were 1.11 (95% CI, 1.02-1.20) for total and 1.30 (95% CI, 1.08-1.55) for rectal adenoma. Contrary to adolescent intake, sugar and SSB intake during adulthood was not associated with adenoma risk.

CONCLUSIONS

High intake of simple sugars and SSBs during adolescence was associated with increased risk of conventional adenoma, especially rectal adenoma.

Early-Life Risk Factors for Breast Cancer - Prospective Follow-up in the Northern Finland Birth Cohort 1966

BACKGROUND

While some risk factors for breast cancer have been confirmed, less is known about the role of early biological and social risk factors for breast cancer in adult life.

METHODS

In a prospective follow-up in the Northern Finland Birth Cohort 1966 consisting of 5,308 women, 120 breast cancers were reported via national registers by the end of 2018. Early risk factors were examined with univariate and multivariate analyses using Cox regression analysis. The main results are reported with HRs and their 95% confidence intervals (CI).

RESULTS

In the multivariate-adjusted models, women whose mothers lived in urban areas (HR, 1.68; 95% CI, 1.13-2.51) during pregnancy, were low educated (HR, 2.40; 95% CI, 1.30-4.45), and had been diagnosed with breast cancer (HR, 1.97; 95% CI, 1.09-3.58) had a higher risk for breast cancer in adult life. Lower BMI at the age of 14 associated nonsignificantly with the risk of breast cancer (Mann-Whitney U test, P = 0.087). No association between birth size and breast cancer risk in adult life was found.

CONCLUSIONS

Early-life residence and socioeconomic conditions may have an impact on developing breast cancer in women in adult life. All breast cancer cases of this study were relatively young, and most of them are assumed to be premenopausal.

IMPACT

This study is one of a few prospective birth cohort studies to examine early-life socioeconomic factors and breast cancer risk in adult life. This study is limited due to small number of cases.

Physical Activity and Breast Cancer Prevention: Possible Role of Immune Mediators

There is strong evidence that physical activity (PA) reduces risk, recurrence, and mortality from breast cancer. Emerging data suggest that PA induces changes in inflammatory and immune mediators that may contribute to beneficial effects on breast cancer outcomes. Thus, the goal of this review was to evaluate the evidence linking the protective benefit of PA to modulation of immune responses in breast cancer. A literature search was conducted to identify studies that evaluated the impact of PA on tumor and immune outcomes in breast cancer patients and in mammary tumor models. Nineteen studies investigated the effect of PA interventions on cancer immune outcomes using preclinical breast cancer models. Tumor growth was reduced in 11 studies, unchanged in three studies, and increased in one study. Spontaneous metastasis was reduced in two studies and survival was improved in four studies. Frequently assessed immune outcomes include splenic cell number and function, circulating inflammatory cytokines, and intratumoral immune cells and inflammatory markers. Circulating inflammatory cytokine responses were heterogeneous in preclinical models. Within the tumor microenvironment (TME), several studies documented a change in the infiltration of immune cells with an increase in effector cells and a reduction in immune suppressive cells. Twenty-three studies investigated the effect of PA interventions on immune outcomes in breast cancer patients. Thirteen studies used aerobic PA interventions and 10 studies used a combination of aerobic and resistance exercise interventions. Cycling and treadmill activities were the most commonly used PA modalities. Circulating immune cells and inflammatory cytokines were the most frequently assessed immune outcomes in the clinical studies. Among the 19 studies that evaluated a PA intervention during the post treatment period, 10 reported a reduction in the levels of at least one inflammatory cytokine. No inflammatory cytokines were quantified in the three studies that evaluated a PA intervention during treatment with chemotherapy. Immune outcomes within the tumor were assessed in only one study performing a PA intervention prior to surgery. Results from preclinical and clinical studies suggest that PA exerts heterogeneous effects on inflammatory cytokines, but may alter the gene expression profile and immune infiltrates in the tumor which may result in a reduction in immunosuppressive factors. However, additional studies are needed to better understand the effect of PA on immune outcomes in the TME.

Association of physical activity, body mass index and reproductive history with breast cancer by menopausal status in Iranian women

BACKGROUND

The incidence rate of breast cancer (BC) is increasing in low- and middle-income countries (LMICs), including Iran. We investigated the association between BC risk and physical activity (PA), body mass index (BMI), and reproductive history among Iranian women.

METHODS

We conducted a large hospital-based case-control study and compared 958 BC cases with 967 controls at the Cancer Institute of Iran during 2011-2016. We used multiple logistic regression models and adjusted for potential confounders to estimate odds ratios (ORs) and 95% confidence intervals (95%CIs) for the associations between BC and different risk factors, including low physical activity.

RESULTS

Women with high levels of physical activity had a lower risk of BC compared to those who were inactive (OR = 0.55, 95%CI: 0.41, 0.75). In premenopausal women, the association was observed only in normal-weight women (OR = 0.31, 95%CI: 0.13, 0.75), while it was limited to obese women in the postmenopausal group (OR = 0.29, 95%CI: 0.12, 0.66). We found a high risk of postmenopausal BC among overweight (OR = 1.69; 95%CI: 1.01, 2.81) and obese women (OR = 1.9; 95%CI: 1.14, 3.14) compared to women with a normal BMI. We observed an inverse association among postmenopausal women who had between three and five children (OR = 0.31, 95%CI 0.14, 0.64) and more than six children (OR = 0.21, 95%CI 0.12, 0.42) compared to nulliparous women.

CONCLUSIONS

Low levels of physical activity, low parity, and being overweight or obese were major risk factors for BC. For the first time, we report a strong association between physical activity and BC risk in Iranian women.

Domain-specific effects of physical activity on the demand for physician visits

OBJECTIVES

To assess domain-specific effects of physical activity (PA) in the relationship with health care utilization and to investigate whether a measure that aggregates PA across domains (leisure, transport, work) is appropriate.

METHODS

Data were retrieved from a longitudinal cohort study conducted in Southern Germany (women n = 1330, men n = 766). The number of physician visits was regressed on total PA and on PA differentiated by the domains leisure time, travel time and working time in a negative binomial model.

RESULTS

For women, no association with physician visits is found for total PA, while high leisure time physical activity (LTPA) is associated with 22% more visits. The effect of high LTPA is statistically different from the effect of high total PA. For men, no significant associations are found for both measures.

CONCLUSIONS

The specific, positive effect of high LTPA on physician visits among women shows that using an aggregate measure of PA is inappropriate for analyzing the relation between PA and health care utilization. Further, the positive relationship should be considered in attempts to promote physical activity.

Prospective Study of Dietary Patterns and Hearing Threshold Elevation

We conducted a prospective study of dietary patterns and longitudinal change in audiometric hearing thresholds among 3,135 women (mean age = 59 years) in the Nurses' Health Study II (2012-2018). Diet adherence scores for the Dietary Approaches to Stop Hypertension (DASH) and Alternate Mediterranean (AMED) diets and the Alternate Healthy Eating Index 2010 (AHEI-2010) were calculated using validated food-frequency questionnaires. Baseline and 3-year follow-up hearing sensitivities were assessed by pure-tone audiometry at 19 US sites. We used multivariable-adjusted logistic regression models to examine independent associations between diet adherence scores and risk of ≥5 dB elevation in the pure-tone average (PTA) of low-frequency (LPTA0.5,1,2 kHz), mid-frequency (MPTA3,4 kHz), and high-frequency (HPTA6,8 kHz) hearing thresholds. Higher adherence scores were associated with lower risk of hearing loss. Compared with the lowest quintile of DASH score, the multivariable-adjusted odds ratios for mid-frequency and high-frequency threshold elevation in the highest quintile were 0.71 (95% confidence interval (CI): 0.55, 0.92; P for trend = 0.003) and 0.75 (95% CI: 0.59, 0.96; P for trend = 0.02); for AMED and AHEI scores, for mid-frequency threshold elevation, they were 0.77 (95% CI: 0.60, 0.99; P for trend = 0.02) and 0.72 (95% CI: 0.57, 0.92; P for trend = 0.002). Nonsignificant inverse associations were observed for high-frequency threshold elevation. There were no significant associations between adherence scores and low-frequency threshold elevation. Our findings indicate that eating a healthy diet might reduce the risk of acquired hearing loss.

The impact of patient characteristics and lifestyle factors on the risk of an ipsilateral event after a primary DCIS: A systematic review

Objective

The majority of ‘low-risk’ (grade I/II) Ductal Carcinoma In Situ (DCIS) may not progress to invasive breast cancer during a women’s lifetime. Therefore, the safety of active surveillance versus standard surgical treatment for DCIS is prospectively being evaluated in clinical trials. If proven safe and selectively implemented in clinical practice, a significant group of women with low-risk DCIS may forego surgery and radiotherapy in the future. Identification of modifiable and non-modifiable risk factors associated with prognosis after a primary DCIS would also enhance our care of women with low-risk DCIS.

Methods

To identify modifiable and non-modifiable risk factors for subsequent breast events after DCIS, we performed a systematic literature search in PUBMED, EMBASE and Scopus.

Results

Six out of the 3870 articles retrieved were included for final data extraction. These six studies included a total of 4950 patients with primary DCIS and 640 recorded subsequent breast events. There was moderate evidence for an association of a family history of breast cancer, premenopausal status, high BMI, and high breast density with a subsequent breast cancer or further DCIS.

Conclusion

There is a limited number of recent studies published on the impact of modifiable and non-modifiable risk factors on subsequent events after DCIS. The available evidence is insufficient to identify potential targets for risk reduction strategies, reflecting the relatively small numbers and the lack of long-term follow-up in DCIS, a low-event condition.

•

Need for risk management strategies for untreated DCIS patients.

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Limited evidence for association between lifestyle factors and prognosis after DCIS.

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Positive family history, premenopausal status, high breast density associated with prognosis.

Dose-dependent effect of aerobic exercise on inflammatory biomarkers in a randomized controlled trial of women at high risk of breast cancer

BACKGROUND

Increased levels of inflammation are associated with many diseases, including cancer. Physical activity can lower breast cancer risk as well as levels of inflammation. The Women In Steady Exercise Research (WISER) Sister trial was a randomized controlled trial that investigated the effects of a dosed, moderate to vigorous, aerobic exercise intervention on levels of inflammation in premenopausal women who were at high risk of developing breast cancer.

METHODS

Participants were randomized to control (<75 minutes per week; 41 patients), low-dose exercise (150 minutes per week; 38 patients), or high-dose exercise (300 minutes per week; 37 patients) groups. The 5-menstrual cycles-long, home-based treadmill exercise intervention gradually increased in minutes per week and intensity up to a maximum of 80% of the age-predicted maximum heart rate. Blood was collected at baseline and at follow-up and assayed for chemokine (C-C motif) ligand 2 (CCL2), interleukin 10 (IL-10), interleukin 12 (IL-12), and tumor necrosis factor α (TNF-α).

RESULTS

A linear dose-response relationship was observed for the proinflammatory biomarkers CCL2 (%Δ of -5.44% in the control group, -0.03% in the low-dose exercise group, and 1.54% in the high-dose exercise group), IL-12 (%Δ of -21.5% in the control group, 38.2% in the low-dose exercise group, and 25.8% in the high-dose exercise group,) and TNF-α (%Δ of -4.69% in the control group, 9.51% in the low-dose exercise group, and 15.7% in the high-dose exercise group) but not for the anti-inflammatory biomarker IL-10 (%Δ of 5.05% in the control group, 6.05% in the low-dose exercise group, and 10.6% in the high-dose exercise group). For IL-12 and TNF-α, the percentage change was significantly higher in the low-dose (IL-12: P < .001; and TNF-α: P = .01) and high-dose (IL-12: P < .001; and TNF-α: P < .001) exercise groups compared with the control group.

CONCLUSIONS

Moderate to vigorous aerobic exercise appeared to increase levels of proinflammatory biomarkers in a dose-dependent manner in a population of healthy women at high risk of developing breast cancer. The results of the current study suggest that for healthy premenopausal women, the mechanism of reduced breast cancer risk observed in physically active individuals may not be a result of reduced levels of inflammation.

World Cancer Research Fund International: Continuous Update Project-systematic literature review and meta-analysis of observational cohort studies on physical activity, sedentary behavior, adiposity, and weight change and breast cancer risk

PURPOSE

The purpose of the present study was to systematically review the complex associations between energy balance-related factors and breast cancer risk, for which previous evidence has suggested different associations in the life course of women and by hormone receptor (HR) status of the tumor.

METHODS

Relevant publications on adulthood physical activity, sedentary behavior, body mass index (BMI), waist and hip circumferences, waist-to-hip ratio, and weight change and pre- and postmenopausal breast cancer risk were identified in PubMed up to 30 April 2017. Random-effects meta-analyses were conducted to summarize the relative risks across studies.

RESULTS

One hundred and twenty-six observational cohort studies comprising over 22,900 premenopausal and 103,000 postmenopausal breast cancer cases were meta-analyzed. Higher physical activity was inversely associated with both pre- and postmenopausal breast cancers, whereas increased sitting time was positively associated with postmenopausal breast cancer. Although higher early adult BMI (ages 18-30 years) was inversely associated with pre- and postmenopausal breast cancers, adult weight gain and greater body adiposity increased breast cancer risk in postmenopausal women, and the increased risk was evident for HR+ but not HR- breast cancers, and among never but not current users of postmenopausal hormones. The evidence was less consistent in premenopausal women. There were no associations with adult weight gain, inverse associations with adult BMI (study baseline) and hip circumference, and non-significant associations with waist circumference and waist-to-hip ratio that were reverted to positive associations on average in studies accounting for BMI. No significant associations were observed for HR-defined premenopausal breast cancers.

CONCLUSION

Better understanding on the impact of these factors on pre- and postmenopausal breast cancers and their subtypes along the life course is needed.

Physical activity is not related to risk of early menopause in a large prospective study

STUDY QUESTION

Is physical activity associated with incident early menopause?

SUMMARY ANSWER

Physical activity is not associated with incident early menopause.

WHAT IS KNOWN ALREADY

Lifestyle factors such as physical activity may influence menopause timing, but results from prior research are inconsistent.

STUDY DESIGN, SIZE, DURATION

We evaluated the association between physical activity and the occurrence of early natural menopause in a prospective cohort study, the Nurses' Health Study II. Women were followed prospectively from 1989 to 2011.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Our analysis included 107 275 women who were premenopausal at baseline. Menopause status was self-reported biennially. Time per week participating in specific activities was reported approximately every 4 years and used to calculate metabolic task hours per week (MET h/week). We used Cox proportional hazards model to evaluate the association between physical activity and incidence of natural menopause before age 45 years while controlling for potential confounding factors.

MAIN RESULTS AND THE ROLE OF CHANCE

There were 2 786 study members who experienced menopause before the age of 45. After adjustment for age, smoking and other factors, we observed no association between adulthood physical activity and early menopause. For example, compared to women reporting <3 MET h/week, the hazard ratio for women in the highest category (≥42 MET h/week) of cumulatively-averaged total physical activity was 0.89 (95% confidence interval: 0.76-1.04; P-trend: 0.26). Neither moderate nor strenuous activity in adolescence and young adulthood were related to risk. The relation of physical activity and early menopause did not vary across strata of body mass index or smoking status.

LIMITATIONS, REASONS FOR CAUTION

Physical activity and menopausal status were self-reported, but repeated assessment of physical activity and prospective report of menopause status likely reduce the potential for non-differential misclassification. While the majority of our study participants were white, it is unlikely that the physiological relation of activity and early menopause varies by ethnicity.

WIDER IMPLICATIONS OF THE FINDINGS

Findings from our large prospective study do not support an important association between physical activity and early menopause.

STUDY FUNDING/COMPETING INTEREST(S)

This project was supported by UM1CA176726 and R01HD078517 from the National Institutes of Health, Department of Health and Human Services. No competing interests are declared.

TRIAL REGISTRATION NUMBER

N/A.

Breast Cancer Metabolomics: From Analytical Platforms to Multivariate Data Analysis. A Review

Cancer is a major health issue worldwide for many years and has been increasing significantly. Among the different types of cancer, breast cancer (BC) remains the leading cause of cancer-related deaths in women being a disease caused by a combination of genetic and environmental factors. Nowadays, the available diagnostic tools have aided in the early detection of BC leading to the improvement of survival rates. However, better detection tools for diagnosis and disease monitoring are still required. In this sense, metabolomic NMR, LC-MS and GC-MS-based approaches have gained attention in this field constituting powerful tools for the identification of potential biomarkers in a variety of clinical fields. In this review we will present the current analytical platforms and their applications to identify metabolites with potential for BC biomarkers based on the main advantages and advances in metabolomics research. Additionally, chemometric methods used in metabolomics will be highlighted.

Physical activity during adolescence and risk of colorectal adenoma later in life: results from the Nurses' Health Study II

Background

Physical activity during adulthood has been consistently associated with lower risk of colorectal cancers, but whether physical activity during adolescence may also play a role in colorectal carcinogenesis is unclear.

Methods

We included 28,250 women in the Nurses’ Health Study II who provided data on physical activity during adolescence (ages 12–22 years) in 1997 and underwent lower bowel endoscopy (1998–2011). We used logistic regression models for clustered data to examine the association between physical activity during adolescence and risk of adenoma later in life.

Results

Physical activity during adolescence was inversely associated with risk of colorectal adenoma (2373 cases), independent of physical activity during adulthood. The multivariable-adjusted odds ratio (OR) of adenoma was 0.89 (95% CI 0.77–1.02; P_trend = 0.03) comparing women with ≥ 72 metabolic equivalent of tasks-hours/week (MET-h/week) to < 21 MET-h/week. Women with high physical activity during both adolescence (≥53.3 MET-h/week) and adulthood (≥23.1 MET-h/week) had significantly lower risk of adenoma (all adenomas: OR 0.76; 95% CI 0.66–0.88; advanced adenoma: OR 0.61; 95% CI 0.45–0.82) compared to women with low physical activity during both stages of life.

Conclusions

Our findings suggest that physical activity during adolescence may lower the risk of colorectal adenoma later in life.

ARPC2 promotes breast cancer proliferation and metastasis

Actin-related protein 2/3 complex (ARPC2) is an actin‑binding component involved in the regulation of actin polymerization. It mediates the formation of branched actin networks and contacts the mother actin filament. Migration and invasion are key processes which enable tumor cells to infiltrate blood vessels or lymphatic vessels, and the actin pathway plays a very important role. Given that ARPC2 is critical to this progression, the present study focused on ARPC2 activity in breast cancer (BrCa) cell invasion and migration. Limited data are available on the expression and role of ARPC2 proteins in breast carcinomas. We screened the Oncomine database for messenger RNAs (mRNAs) that are upregulated in BrCa and found that ARPC2 was one of the most consistently involved mRNAs in BrCa. The analysis of immunohistochemical data revealed that ARPC2 expression was higher in breast cancerous tissues than in adjacent non‑cancerous tissues. In addition, ARPC2 was highly associated with the tumor stage, nodal metastasis, and overall survival of patients with BrCa. We performed siRNA‑ARPC2 transfection to investigate the effect of ARPC2 on the proliferation, migration, invasion and arrest of BrCa cells. It was revealed that ectopic ARPC2 expression significantly upregulated N‑cadherin, vimentin, ZEB1, MMP‑9 and MMP‑3 expression and also activated the TGF‑β pathway to contribute to epithelial‑mesenchymal transition (EMT). These results collectively indicated that ARPC2 promoted the tumorigenesis of breast carcinoma and the initiation of EMT. Therefore, ARPC2 was revealed to be a potential therapeutic target in patients with BrCa.

Abdominal Adiposity and Physical Inactivity Are Positively Associated with Breast Cancer: A Case-Control Study

OBJECTIVE

To examine whether breast cancer is associated with body composition and level of physical activity, considering the menstrual status.

METHODS

This was a case-control study with 116 women recently diagnosed with breast cancer and 226 controls. Body composition was assessed by dual-energy X-ray absorptiometry, and cardiometabolic risk was assessed by conicity index and waist-to-height ratio. The short version of the International Physical Activity Questionnaire was used to estimate the level of physical activity. All analyses were adjusted for age and BMI.

RESULTS

The total body fat percentage, android body fat, android-gynoid ratio, and waist circumference were positively associated (p < 0.05), whereas the percentage of lean body mass (p <0.05) and the level of physical activity (p < 0.01) were inversely associated with breast cancer in premenopausal women. Among postmenopausal women, physical activity decreased the chance of developing breast cancer by 49% (95% CI = 0.29 to 0.92, p = 0.02).

CONCLUSION

A low percentage of lean body mass and high abdominal adiposity in the premenopausal period increase the chances of developing breast cancer. Regular physical activity is inversely associated with breast cancer in pre- and postmenopausal women.

Towards Prevention of Breast Cancer: What Are the Clinical Challenges?

The dramatic increase in breast cancer incidence compels a paradigm shift in our preventive efforts. There are several barriers to overcome before prevention becomes an established part of breast cancer management. The objective of this review is to identify the clinical challenges for improved breast cancer prevention and discuss current knowledge on breast cancer risk assessment methods, risk communication, ethics, and interventional efforts with the aim of covering the aspects relevant for a breast cancer prevention trial. Herein, the following five areas are discussed: (i) Adequate tools for identification of women at high risk of breast cancer suggestively entitled Prevent! Online. (ii) Consensus on the definition of high risk, which is regarded as mandatory for all risk communication and potential prophylactic interventions. (iii) Risk perception and communication regarding risk information. (iv) Potential ethical concerns relevant for future breast cancer prevention programs. (v) Risk-reducing programs involving multileveled prevention depending on identified risk. Taken together, devoted efforts from both policy makers and health care providers are warranted to improve risk assessment and risk counseling in women at risk for breast cancer to optimize the prevention of breast cancer. Cancer Prev Res; 11(5); 255-64. ©2018 AACR.

Early Life Exposures and Adult Cancer Risk

Very little is known about the influence of early life exposures on adult cancer risk. The purpose of this narrative review was to summarize the epidemiologic evidence relating early life tobacco use, obesity, diet, and physical activity to adult cancer risk; describe relevant theoretical frameworks and methodological strategies for studying early life exposures; and discuss policies and research initiatives focused on early life. Our findings suggest that in utero exposures may indirectly influence cancer risk by modifying biological pathways associated with carcinogenesis; however, more research is needed to firmly establish these associations. Initiation of exposures during childhood and adolescence may impact cancer risk by increasing duration and lifetime exposure to carcinogens and/or by acting during critical developmental periods. To expand the evidence base, we encourage the use of life course frameworks, causal inference methods such as Mendelian randomization, and statistical approaches such as group-based trajectory modeling in future studies. Further, we emphasize the need for objective exposure biomarkers and valid surrogate endpoints to reduce misclassification. With the exception of tobacco use, there is insufficient evidence to support the development of new cancer prevention policies; however, we highlight existing policies that may reduce the burden of these modifiable risk factors in early life.

Physical activity during adolescence and young adulthood and the risk of breast cancer in BRCA1 and BRCA2 mutation carriers

BACKGROUND

Physical activity is inversely associated with the risk of breast cancer among women in the general population. It is not clear whether or not physical activity is associated with the risk of BRCA-associated breast cancer.

METHODS

We conducted a case-control study of 443 matched pairs of BRCA mutation carriers to evaluate the association between physical activity and breast cancer risk. Moderate and vigorous physical activities at ages 12-13, ages 14-17, ages 18-22, ages 23-29 and ages 30-34 were determined using the Nurses' Health Study II Physical Activity Questionnaire. We estimated mean metabolic equivalent task hours/week for moderate, vigorous and total physical activities overall (ages 12-34), during adolescence (ages 12-17) and during early adulthood (ages 18-34). Logistic regression analysis was used to estimate the odds ratios (OR) and 95% confidence intervals (CI) for total, moderate and strenuous recreational physical activities and breast cancer risk, by menopausal status.

RESULTS

Overall, there was no significant association between total physical activity and subsequent breast cancer risk (OR_{Q4 vs. Q1} = 1.01, 95% CI 0.69-1.47; P-trend = 0.72). Moderate physical activity between ages 12-17 was associated with a 38% decreased risk of premenopausal breast cancer (OR_{Q4 vs. Q1} = 0.62; 95% CI 0.40-0.96; P-trend = 0.01). We found no association between exercise and breast cancer diagnosed after menopause.

CONCLUSIONS

These findings suggest that early-life physical activity is associated with a reduced risk of premenopausal breast cancer among BRCA mutation carriers.

IMPACT

Future prospective analyses, complemented by mechanistic evidence, are warranted in this high-risk population.

Adolescent Physical Activity and Endometriosis Risk

Background

In the one study examining the relationship, adolescent physical activity was not associated with risk for endometriosis. Case-control studies have shown 40–80% reductions in risk for adult activity, while only an 11% reduction in endometriosis risk was observed in a recent prospective analysis.

Methods

Using data collected from the Nurses’ Health Study II, a prospective cohort study of premenopausal US nurses that began in 1989, we have attempted to clarify this relation. Data are updated every 2 yrs with follow-up for these analyses through to 2001. Women reported the average amount of time per week spent in moderate and strenuous recreational activity during three age periods: ages 12–13, ages 14–17, and ages 18–22. A metabolic equivalent (MET) score was assigned to each activity and these were summed to estimate total activity.

Results

During 637,747 person-years of follow-up, 1,481 cases of laparoscopically confirmed endometriosis were reported among women with no past infertility. After adjusting for age, calendar time, birth weight, age at menarche, parity, oral contraceptive use, and body mass index (BMI), we observed a 16% increase in the risk for endometriosis comparing the greatest amount of activity (≥80 MET-h/wk) with the least (<20 MET-h/wk) during ages 12–13 (RR=1.16, 95% CI=0.98–1.37, p-value test for trend=0.02), and no associations for ages 14–17 or ages 18–22. In analyses of the individual activity types within each time period, only strenuous activity during ages 12–13 was associated with endometriosis.

Conclusions

We did not find evidence of a beneficial association between adolescent physical activity and laparoscopically confirmed endometriosis, but in fact found a small increase in risk.

The Premenopausal Breast Cancer Collaboration: A Pooling Project of Studies Participating in the National Cancer Institute Cohort Consortium

Breast cancer is a leading cancer diagnosis among premenopausal women around the world. Unlike rates in postmenopausal women, incidence rates of advanced breast cancer have increased in recent decades for premenopausal women. Progress in identifying contributors to breast cancer risk among premenopausal women has been constrained by the limited numbers of premenopausal breast cancer cases in individual studies and resulting low statistical power to subcategorize exposures or to study specific subtypes. The Premenopausal Breast Cancer Collaborative Group was established to facilitate cohort-based analyses of risk factors for premenopausal breast cancer by pooling individual-level data from studies participating in the United States National Cancer Institute Cohort Consortium. This article describes the Group, including the rationale for its initial aims related to pregnancy, obesity, and physical activity. We also describe the 20 cohort studies with data submitted to the Group by June 2016. The infrastructure developed for this work can be leveraged to support additional investigations. Cancer Epidemiol Biomarkers Prev; 26(9); 1360-9. ©2017 AACR.

Validity of the Nurses' health study physical activity questionnaire in estimating physical activity in adults with rheumatoid arthritis

Background

Patients with rheumatoid arthritis (RA) demonstrate reduced aerobic capacity, excess cardiovascular risk, mobility limitations and are less physically active than their healthy peers. Physical activity may decrease RA disease activity through its anti-inflammatory effects and psychological and health benefits. To successfully manage RA symptoms and reduce cardiovascular risks associated with RA through increased physical activity (PA), accurate physical activity assessments are critical. Accelerometry is an objective physical activity measure, but not widely used. Validity of the Nurses’ Health Study physical activity questionnaire II (NHSPAQ) has not been determined for estimation of physical activity in RA. This study examined NHSPAQ validity in adults with RA compared to accelerometry-based metabolic equivalents determined (METs) and results of performance tests. We hypothesized NHSPAQ scores would correlate moderately (0.4–0.5) with accelerometer physical activity estimates.

Methods

Thirty-five adults with RA (mean age [SD] 62 (Williams et. al, Health Qual Life Outcomes10:28, 2012) years, 28 females (80%) recruited from a hospital-based clinic registry participated in a one-week accelerometry trial. Medical data was compiled. Participants completed the NHSPAQ, a self-paced 20-m walk test, and modified timed step test. Participants wore an accelerometer for 7 consecutive days, then completed a physical activity log and another NHSPAQ. Metabolic equivalents (METs) were derived from NHSPAQ and accelerometers using standardized formulas. NHSPAQ METs were correlated with accelerometer METs and data from performance measures.

Results

Average disease duration was 21 years (SD = 11), 63% patients took biologics. The average weekly METs reported were 29 (SD = 33) and accelerometer METs were 33 (SD = 22). NHSPAQ METs correlated moderately with accelerometer-derived METs (r = 0.48 95% CI (0.15–0.70). Self-reported PA correlated moderately with Step Test performance (r = 0.50 95% CI (0.18–0.72).

Conclusion

Patients with RA exhibit low physical activity levels. General fitness measures were moderately correlated with physical activity levels. A moderate significant correlation existed between NHSPAQ and accelerometry METs. These preliminary data suggest the NHSPAQ may be useful to describe physical activity levels in this population.

Childhood and teenage physical activity and breast cancer risk

PURPOSE

Adult physical activity is associated with reduced breast cancer risk, but few studies have evaluated activity before adulthood. Early life may be an important period because of rapid breast development and hormonal changes. This study contributes new information by examining childhood (ages 5-12) and teenage (ages 13-19) activity separately and overall.

METHODS

The Sister Study is a cohort of 50,884 women aged 35-74. Women reported age 5-19 sports/exercise activities and age 10 and 16 unstructured activities. Both hours and MET-hours of activity were considered in association with breast cancer overall, by ER status, and by menopausal status. Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated with Cox proportional hazards models.

RESULTS

2416 cases were diagnosed during follow-up (mean = 6.4 years). Participation in 7+ hours (vs <1 h) per week of sports/exercise during ages 5-19 was associated with reduced breast cancer risk (HR = 0.75; 95% CI 0.57-0.99). 7+ hours (vs <1 h) per week of unstructured physical activity at age 16, but not age 10, was inversely associated with breast cancer (HR = 0.81; 95% CI 0.70-0.95). Associations were more pronounced for ER+ tumors, especially for activity during the childhood (ages 5-12) period. Due to low correlation between childhood/teenage and adulthood activity in this study (r = 0.1), it is unlikely that recent activity explains our results.

CONCLUSIONS

Findings from this large cohort indicate higher levels of physical activity during ages 5-19 are inversely associated with breast cancer risk, supporting early life as a window of susceptibility for breast cancer development.

Is There a Relationship Between Perceived Neighborhood Contentedness and Physical Activity in Young Men and Women

The relationship between perceived neighborhood contentedness and physical activity was evaluated in the Add Health study population. Wave I includes 20,745 respondents (collected between 1994 and 1995) and wave II includes 14,738 (71 %) of these same students (collected in 1996). Multinomial logistic regression was used to evaluate this relationship in both wave I and wave II of the sample. Higher levels of Perceived Neighborhood Contentedness were associated with higher reports of physical activity in both males and females and in both waves. For every one-point increment in PNS, males were 1.3 times as likely to report being highly physically active than low (95 % CI 1.23-1.37) in wave 1 and 1.25 times as likely in wave 2 (95 % CI 1.17-1.33). Females were 1.17 (95 % CI 1.12-1.22) times as likely to report being highly active than low and 1.22 times as likely in wave 2 (95 % CI 1.17-1.27) with every one-point increment. PNC appears to be significantly associated with physical activity in adolescents. Involving the community in the development of intervention programs could help to raise the contentedness of adolescents in these communities.

Physical activity and the incidence of multiple sclerosis

OBJECTIVE

To study whether physical activity during adulthood or early life is associated with multiple sclerosis (MS) incidence in 2 prospective cohorts of women.

METHODS

Women in the Nurses' Health Study (NHS) (n = 81,723; 1986-2004) and NHS II (n = 111,804; 1989-2009) reported recent physical activity at baseline and in selected follow-up questionnaires. Using this information, we calculated total metabolic equivalent hours of physical activity per week, a measure of energy expenditure. There were 341 confirmed MS cases with first symptoms after baseline. Participants also reported early-life activity. To estimate relative rates (RRs) and 95% confidence intervals (CIs), we used Cox proportional hazards models, adjusting for age, latitude of residence at age 15, ethnicity, smoking, supplemental vitamin D, and body mass index at age 18.

RESULTS

Compared with women in the lowest baseline physical activity quartile, women in the highest quartile had a 27% reduced rate of MS (RR_pooled = 0.73, 95% CI 0.55-0.98; p-trend 0.08); this trend was not present in 6-year lagged analyses. Change in physical activity analyses suggested that women reduced activity before onset of MS symptoms. In NHS and NHS II, higher strenuous activity at ages 18-22 years was weakly associated with a decreased MS rate. However, in NHS II, total early-life activity at ages 12-22 was not associated with MS.

CONCLUSIONS

Though higher physical activity at baseline was weakly associated with lower MS risk, this may have been due to women reducing physical activity in response to subclinical MS.

Physical activity from menarche to first pregnancy and risk of breast cancer

Breast tissue is particularly susceptible to exposures between menarche and first pregnancy, and a longer interval between these reproductive events is associated with elevated breast cancer risk. Physical activity during this time period may offset breast cancer risk, particularly for those at highest risk with longer menarche-to-first-pregnancy intervals. We used data from 65,576 parous women in the Nurses' Health Study II free of cancer in 1989 (baseline) and recalled their leisure-time physical activity at ages 12-34 in 1997. Current activity was collected at baseline and over follow-up. Relative risks (RRs) were estimated using multivariable Cox proportional hazards regression models. Between 1989 and 2011, 2,069 invasive breast cancer cases were identified. Total recreational activity between menarche and first pregnancy was not significantly associated with the risk of breast cancer. However, physical activity between menarche and first pregnancy was associated with significantly lower breast cancer risk among women in the highest category of a menarche-to first-pregnancy interval (≥20 years; RR for the highest versus the lowest quartile = 0.73, 95% confidence interval = 0.55-0.97; Ptrend  = 0.045; Pinteraction  = 0.048). This was not observed in women with a shorter interval. Physical activity between menarche and first pregnancy was associated with a lower risk of breast cancer among women with at least 20 years between these reproductive events. This may provide a modifiable factor that women can intervene on to mitigate their breast cancer risk associated with a longer interval.

Vigorous physical activity and risk of breast cancer in the African American breast cancer epidemiology and risk consortium

The relationship between physical activity and breast cancer risk has been extensively studied among women of European descent, with most studies reporting inverse associations. However, data on American women of African ancestry (AA) and by tumor subtypes are sparse. Thus, we examined associations of vigorous exercise and breast cancer risk overall, and by estrogen receptor (ER) status, in the African American Breast Cancer Epidemiology and Risk Consortium. We pooled data from four large studies on 2482 ER+ cases, 1374 ER- cases, and 16,959 controls. Multivariable logistic regression was used to compute odds ratios (OR) and 95 % confidence intervals (CI) for the risk of breast cancer overall, and polytomous logistic regression was used to model the risk of ER+ and ER- cancer. Recent vigorous exercise was associated with a statistically significant, modestly decreased risk for breast cancer overall (OR 0.88, 95 % CI 0.81-0.96) and for ER+ cancer (OR 0.88, 95 % CI 0.80-0.98), but not for ER- cancer (OR 0.93, 95 % CI 0.82-1.06). Overall, there was no strong evidence of effect modification by age, menopausal status, body mass index, and parity. However, our data were suggestive of modification by family history, such that an inverse association was present among women without a family history but not among those with a relative affected by breast cancer. Results from this large pooled analysis provide evidence that vigorous physical activity is associated with a modestly reduced risk of breast cancer in AA women, specifically ER+ cancer.

Psychosocial Adjustment and Perceived Risk Among Adolescent Girls From Families With BRCA1/2 or Breast Cancer History

PURPOSE

To evaluate the impact of breast cancer family history and maternal BRCA1/2 mutation on the psychosocial adjustment and perceived risk in girls age 11 to 19 years old.

MATERIALS AND METHODS

Girls age 11 to 19 years old with one or more relatives with breast cancer or a familial BRCA1/2 mutation (breast cancer family history [BCFH] positive, n = 208; n = 69 with BRCA1/2-positive mother), peers (BCFH negative, n = 112), and their mothers completed assessments of psychosocial adjustment, breast cancer-specific distress, and perceived risk of breast cancer.

RESULTS

General psychosocial adjustment did not differ significantly between BCFH-positive and BCFH-negative girls, either by self-report or mother report, except for higher self-esteem among BCFH-positive girls (P = .01). BCFH-positive girls had higher breast cancer-specific distress than BCFH-negative girls (P < .001), but girls from BRCA1/2-positive families did not differ from other BCFH-positive peers. BCFH-positive girls were more likely to report themselves at increased self-risk for breast cancer in adulthood than BCFH-negative peers (74% v 33%, respectively; P ≤ .001). Girls from BRCA1/2-positive families were more likely than other BCFH-positive and BCFH-negative peers to report themselves at increased risk (P < .001). In all groups, perceived risk of breast cancer was associated with older age. Higher breast cancer-specific distress among adolescent girls was associated with higher self-perceived risk of breast cancer and higher maternal breast cancer-specific distress.

CONCLUSION

Adolescent girls from BRCA1/2-positive and breast cancer families have higher self-esteem and do not have poorer psychosocial adjustment than peers. However, they do experience greater breast cancer-specific distress and perceived risk of breast cancer, particularly among older girls. Understanding the impact is important to optimize responses to growing up in families at familial and genetic risk for breast cancer, particularly given the debate over the genetic testing of children for cancer susceptibility in adulthood.

Recreational physical activity and risk of triple negative breast cancer in the California Teachers Study

BACKGROUND

Evidence has accumulated showing that recreational physical activity reduces breast cancer risk. However, it is unclear whether risk reduction pertains to specific receptor-defined subtypes. Moreover, few studies have examined whether changes in the amount of recreational physical activity during adulthood influence breast cancer risk.

METHODS

A total of 108,907 women, ages 22 to 79 years with no history of breast cancer when joining the California Teachers Study in 1995-1996, completed a baseline questionnaire and were eligible for the study. Through 2012, 5882 women were diagnosed with invasive breast cancer. Breast cancer subtypes were defined by the expression status of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2). Multivariable Cox proportional hazards models provided adjusted hazard ratios (HRs) and 95 % confidence intervals (CIs) for breast cancer overall and ER/PR/HER2-defined subtypes associated with long-term (from high school through age 54 or age at cohort entry, whichever was younger) and baseline (during 3 years prior to baseline) recreational physical activity. Among women who also completed a follow-up questionnaire at 10 years after baseline in 2005-2008 (54,686 women, 1406 with invasive breast cancer), risk associated with changes in the amount of recreational physical activity from baseline to the 10-year follow-up (during 3 years prior to the 10-year follow-up) was determined.

RESULTS

Both long-term and baseline strenuous recreational physical activity were inversely associated with risk of invasive breast cancer (P trend ≤0.03). The observed associations were mainly confined to women with triple negative breast cancer (TNBC, ER-/PR-/HER2-, P trend ≤0.02) or luminal A-like subtype (ER+ or PR+ plus HER2-) who were former users of menopausal hormone therapy at baseline (P trend = 0.02, P homogeneity of trends ≤0.03). Moreover, women who consistently engaged in the highest level (≥3.51 h/wk/y) of strenuous recreational physical activity between baseline and 10-year follow-up had the lowest risk of breast cancer (HR = 0.71, 95 % CI = 0.52-0.98) when compared to those who were consistently low (≤0.50 h/wk/y).

CONCLUSIONS

Strenuous recreational physical activity is associated with lower breast cancer risk, especially TNBC. The benefit may be maximized by consistently engaging in high-intensity recreational physical activity during adulthood.

Potential breast cancer risk factors among Saudi women aged 19-50 years in Jeddah: a case-control study

BACKGROUND AND OBJECTIVES

The Saudi cancer registry reported in 2009 that the frequency of breast cancer is the highest among all types of cancer among Saudi women aged 30-59 years. The Makkah region had the second highest frequency of reported breast cancer cases, with patients having a median age of 46 years. The objectives of this study were to explore the distribution of selected known and hypothetically claimed breast cancer risk factors among Saudi women aged 19-50 years and describe the association of breast cancer with selected risk factors.

DESIGN AND SETTING

An unmatched case-control study was conducted on breast cancer cases at three different hospitals in Jeddah.

PATIENTS AND METHODS

Online OpenEpi was used and the method of Kelsey and colleagues was selected from OpenEpi output; the calculated number of cases and controls was 134 each. Women aged 19-50 years were included and the analysis was conducted on 151 cases and 166 controls as they met the age inclusion criteria.

RESULTS

The mean age of patients was 40 years. A subgroup analysis for age at menarche less than 12 years showed an odds ratio (OR) of 1.4 6 [95% confidence interval (CI) 0.88-2.44]. A high proportion of cases reported the use of exogenous estrogen and progesterone (OR=4.7, 95% CI 1.7-13.0), previous mammography screening (89% of cases vs. 11% of controls), and affected family members (4.6 vs. 1.8, OR=2.64 [95% CI 0.67-10.4]. The OR for exercise frequency in the study group was 1.45 (95% CI 0.90-2.35). The OR for breastfeeding among mothers who breast-fed for more than 12 months was 0.56 (95% CI 0.35-0.88).

CONCLUSION AND RECOMMENDATIONS

This study provides information on associative factors such as early age at menarche (<12 years), monthly income of at least 20 000 SR (5333 USD), use of exogenous estrogen and progesterone, previous biopsies/surgeries, previous clinical breast examination and mammography screening, and affected family members. Protective factors among premenopausal women, such as breastfeeding and exercising, have been described. Conducting comprehensive sessions on breastfeeding and physical education targeting young generations is highly recommended in order to reduce the risk for breast cancer among Saudi women aged 19-50 years.

The Dose-Response Effects of Aerobic Exercise on Body Composition and Breast Tissue among Women at High Risk for Breast Cancer: A Randomized Trial

Observational data indicate that behaviors that shift energetic homeostasis, such as exercise, may decrease the risk of developing breast cancer by reducing the amount of energy-dense, metabolically active adipose tissue. Between December 2008 and April 2013, we conducted a single-blind, 5-month, clinical trial that randomized premenopausal women at high risk of developing breast cancer to one of three groups: 150 min/wk of aerobic exercise (low dose), 300 min/wk of aerobic exercise (high dose), or control. Body composition was assessed using dual-energy x-ray absorptiometry. Background parenchymal enhancement (BPE) was quantified using computerized algorithms on breast dynamic contrast-enhanced MRI. Over 5 months, compared with the control group: the low-dose and high-dose groups lost -1.5 ± 0.5 and -1.3 ± 0.5 kg of body mass (linear Ptrend = 0.032); -1.5 ± 0.4 and -1.4 ± 0.3 kg of fat mass (linear Ptrend = 0.003); -1.3 ± 0.3 and -1.4 ± 0.3% of body fat (linear Ptrend < 0.001); -15.9 ± 5.4 and -26.6 ± 5.0 cm(2) of subcutaneous adipose tissue (linear Ptrend < 0.001); and -6.6 ± 1.9 and -5.0 ± 1.9 cm(2) visceral adipose tissue (nonlinear Ptrend = 0.037). For each -1 cm(2) reduction in visceral adipose tissue, BPE decreased by -3.43 ± 1.34 cm(2) (P = 0.010) and explained 9.7% of the variability in BPE. Changes in other aforementioned body composition outcomes did not significantly correlate with changes in BPE. These mechanistic data support observational evidence that shifting energetic homeostasis through exercise may alter the risk of developing breast cancer. Additional adequately powered studies are needed to confirm and expand upon our findings that changes in body composition are associated with changes in BPE. Cancer Prev Res; 9(7); 581-8. ©2016 AACR.

Do Physical Activity Patterns Across the Lifecourse Impact Birth Outcomes?

The significant impact of physical activity during, or immediately prior to pregnancy on a range of pregnancy and birth outcomes has been established. However, lifecourse theory posits that the antecedents of poor outcomes occur across a larger trajectory of time. The objective of this study was to examine whether physical activity patterns over the lifecourse impact birth outcomes. The sample (n = 1,713) was derived from Waves I, III, and IV of the National Longitudinal Study of Adolescent Health and limited to women who had their first, singleton live birth between Waves III and IV; respondents who had missing data were excluded. Outcome variables included preterm birth (<37 weeks) and low birth weight (<5.5 pounds). Physical activity was categorized as follows: long-term physically active (active at Waves I and III); short-term physically active (active at only Wave I or III); and not physically active (not active at Waves I and III). Survey-weighted logistic regression controlled for socio-demographic and established predictors of poor birth outcomes. Women categorized as long-term physically active had lower rates of preterm births (12.2 vs. 18.7 %) and low birth weight (9.1 vs. 11.1 %) compared to women categorized as not physically active. However, when controlling for covariates, adjusted analysis revealed that physical activity consistency only predicted preterm birth (aOR = 0.55, 95 % CI = 0.33-0.91). Findings suggest that physical activity patterns across the lifecourse may decrease risk of preterm birth. Implications include efforts supporting patterns of physical activity over longer periods of time prior to pregnancy.

Physical activity, hormone replacement therapy and breast cancer risk: A meta-analysis of prospective studies

BACKGROUND

Lower risk of breast cancer has been reported among physically active women, but the risk in women using hormone replacement therapy (HRT) appears to be higher. We quantified the association between physical activity and breast cancer, and we examined the influence that HRT use and other risk factors had on this association.

METHODS

After a systematic literature search, prospective studies were meta-analysed using random-effect models applied on highest versus lowest level of physical activity. Dose-response analyses were conducted with studies reporting physical activity either in hours per week or in hours of metabolic equivalent per week (MET-h/week).

RESULTS

The literature search identified 38 independent prospective studies published between 1987 and 2014 that included 116,304 breast cancer cases. Compared to the lowest level of physical activity, the highest level was associated with a summary relative risk (SRR) of 0.88 (95% confidence interval [CI] 0.85, 0.90) for all breast cancer, 0.89 (95% CI 0.83, 0.95) for ER+/PR+ breast cancer and 0.80 (95% CI 0.69, 0.92) for ER-/PR- breast cancer. Risk reductions were not influenced by the type of physical activity (occupational or non-occupational), adiposity, and menopausal status. Risk reductions increased with increasing amounts of physical activity without threshold effect. In six studies, the SRR was 0.78 (95% CI 0.70, 0.87) in women who never used HRT and 0.97 (95% CI 0.88, 1.07) in women who ever used HRT, without heterogeneity in results. Findings indicate that a physically inactive women engaging in at least 150 min per week of vigorous physical activity would reduce their lifetime risk of breast cancer by 9%, a reduction that might be two times greater in women who never used HRT.

CONCLUSION

Increasing physical activity is associated with meaningful reductions in the risk of breast cancer, but in women who ever used HRT, the preventative effect of physical activity seems to be cancelled out.

Psychosocial Adjustment in School-age Girls With a Family History of Breast Cancer

OBJECTIVE

Understanding how young girls respond to growing up with breast cancer family histories is critical given expansion of genetic testing and breast cancer messaging. We examined the impact of breast cancer family history on psychosocial adjustment and health behaviors among >800 girls in the multicenter LEGACY Girls Study.

METHODS

Girls aged 6 to 13 years with a family history of breast cancer or familial BRCA1/2 mutation (BCFH+), peers without a family history (BCFH-), and their biological mothers completed assessments of psychosocial adjustment (maternal report for 6- to 13-year-olds, self-report for 10- to 13-year-olds), breast cancer-specific distress, perceived risk of breast cancer, and health behaviors (10- to 13-year-olds).

RESULTS

BCFH+ girls had better general psychosocial adjustment than BCFH- peers by maternal report. Psychosocial adjustment and health behaviors did not differ significantly by self-report among 10- to 13-year-old girls. BCFH+ girls reported higher breast cancer-specific distress (P = .001) and were more likely to report themselves at increased breast cancer risk than BCFH- peers (38.4% vs 13.7%, P < .001), although many girls were unsure of their risk. In multivariable analyses, higher daughter anxiety was associated with higher maternal anxiety and poorer family communication. Higher daughter breast cancer-specific distress was associated with higher maternal breast cancer-specific distress.

CONCLUSIONS

Although growing up in a family at risk for breast cancer does not negatively affect general psychosocial adjustment among preadolescent girls, those from breast cancer risk families experience greater breast cancer-specific distress. Interventions to address daughter and mother breast cancer concerns and responses to genetic or familial risk might improve psychosocial outcomes of teen daughters.

Links between alcohol consumption and breast cancer: a look at the evidence

Alcohol consumption by adult women is consistently associated with risk of breast cancer. Several questions regarding alcohol and breast cancer need to be addressed. Menarche to first pregnancy represents a window of time when breast tissue is particularly susceptible to carcinogens. Youth alcohol consumption is common in the USA, largely in the form of binge drinking and heavy drinking. Whether alcohol intake acts early in the process of breast tumorigenesis is unclear. This review aims to focus on the influences of timing and patterns of alcohol consumption and the effect of alcohol on intermediate risk markers. We also review possible mechanisms underlying the alcohol-breast cancer association.

The interaction between early-life body size and physical activity on risk of breast cancer

While early-life body leanness is associated with increased breast cancer risk, early-life physical activity may protect against breast cancer. We examined whether the excess risk among lean girls is modified by their levels of prior, concurrent, or future physical activity. We conducted an analysis among 74,723 women in the Nurses' Health Study II (follow-up 1997-2011). Participants recalled their body size at ages 5, 10 and 20 years in 1989 using a 9-level pictogram (Level 1 most lean). In 1997, they reported adolescent levels of physical activity (ages 12-13 and 14-17 years). Cox proportional hazards models estimated the overall association of body size with breast cancer risk and assessed interactions of adolescent physical activity with body size at three different age periods (5-10, 10-20 and 20 years), adjusting for early-life and adult risk factors for breast cancer. Regardless of levels of adolescent physical activity, early-life body leanness (level 1-2 vs. 4.5+) was significantly associated with higher breast cancer risk. The association was slightly attenuated among those who were active (60+ MET-hr/wk) during adolescence compared to those who were inactive (<30 MET-hr/wk) (body size at ages 5-10 years: hazard ratio = 1.37, 95% confidence interval = 1.04-1.81 vs. 1.66, 1.29-2.12), but the interaction was not significant (p = 0.72). The results were similar for body size at three different age periods. Being lean during early life is a risk factor for breast cancer among both inactive and active girls. Adolescent physical activity did not significantly modify the association, although some interaction cannot be excluded.