Domain-specific patterns of physical activity and risk of breast cancer sub-types in the MCC-Spain study

Interaction of sedentary behaviour and educational level in breast cancer risk

OBJECTIVE

This cross-sectional study aims to analyse the relationship between sedentary behaviour and breast cancer (BC) risk from a social perspective.

METHODS

Women aged 45-70 who participated in the Valencia Region Breast Cancer Screening Programme (2018-2019) were included, with a total of 121,359 women analysed, including 506 with cancer and 120,853 without cancer. The response variable was BC (screen-detected) and the main explanatory variable was sedentary behaviour (≤2 / >2-≤3 / >3-≤5 / >5 hours/day, h/d). Nested logistic regression models (M) were estimated: M1: sedentary behaviour adjusted for age and family history of BC; M2: M1 + hormonal/reproductive variables (menopausal status, number of pregnancies, hormone replacement therapy; in addition, months of breastfeeding was added for a subsample of women with one or more live births); M3: M2 + lifestyle variables (body mass index, smoking habits); M4: M3 + socioeconomic variables (educational level, occupation); Final model: M4 + gender variables (childcare responsibilities, family size). Interaction between sedentary behaviour and educational level was analysed in the Final model. Moreover, for the whole sample, postmenopausal women and HR+ BC, the Final model was stratified by educational level.

RESULTS

Sedentary behaviour was associated with an increased risk of BC with a nearly statistically significant effect in the Final model (>2-≤3 h/d: OR = 1.22 (0.93-1.61); >3-≤5 h/d: OR = 1.14 (0.86-1.52); >5: OR = 1.19 (0.89-1.60)). For women with a low educational level, sitting more than 2 h/d was associated with an increased risk of BC in the whole sample (>2-≤3 h/d OR = 1.93 (1.19-3.21); in postmenopausal women (>2-≤3 h/d, OR = 2.12 (1.18-2.96), >5h/d OR = 1.75 (1.01-3.11)) and in HR+ BC (>2-≤3h/d, OR = 2.15 (1.22-3.99)). Similar results were observed for women with one or more live births. Conclusions Sitting >2 h/d is associated with BC risk in women with low educational level, especially in postmenopausal women and those with live births.

Physical Activity and Mammographic Density in Japanese Women

BACKGROUND

Dense breast is one of the strong risk factors for breast cancer among women. While it has been established that physical activity is associated with decreased risk for breast cancer, results have been inconsistent in terms of mammographic density. Thus, we examined physical activity in relation to mammographic density among Japanese women in Tokyo.

METHODS

We used 123,026 records from 33,698 Japanese women without a history of breast cancer who got mammograms at St. Luke's International Hospital in Tokyo, Japan from 2004 to 2019. Mammographic density was classified according to the Breast Imaging Reporting and Data System (BI-RADS), and women self-reported their physical activity level over the past year. ORs were estimated using logistic generalized estimating equations after adjusting for age, body mass index, menopausal status, parity, family history of breast or ovarian cancer, hormone therapy use, smoking status, alcohol consumption, and year.

RESULTS

We observed inverse associations of physical activity with dense breasts. Adjusted ORs were 0.96 (95% confidence interval: 0.91-1.00) for women with physical exercise for 1-2 days per week, 0.94 (0.88-0.99) for those with physical exercise for 3-5 days per week, and 0.91 (0.84-0.99) for those with daily physical exercise when compared with those reported seldom physical exercise.

CONCLUSIONS

Higher levels of physical activity may be associated with decreased mammographic density levels in Japanese women.

IMPACT

Increasing physical activity may serve as a reasonable intervention to reduce mammographic density, and thereby, to mitigate the risk of breast cancer in Asian women.

The association of work physical activity and recreational physical activity with periodontitis in the NHANES (2009-2014)

BACKGROUND

The aim of this study was to investigate the association between different types and intensity of physical activities (PA) and periodontitis in a nationally representative sample of adults in the United States.

METHODS

The data of periodontal condition and PA of 10,714 individuals were obtained from the National Health and Nutrition Examination Survey (NHANES) from 2009 to 2014 and the Global Physical Activity Questionnaire (GPAQ). The association between the prevalence of periodontitis and two PAs (work PA and recreational PA) was respectively analyzed and adjusted by uni- and multi-variable logistic regression models. The odd ratios (ORs), adjusted odd ratios (ORad ), and 95% confidence interval (95% CI) were calculated as the main outcome indicators.

RESULTS

After adjusted by age, sex, race, poverty-income ratio (PIR), diabetes, smoking status, alcohol use, and floss frequency, moderate and vigorous work PAs were significantly correlated with higher odds of periodontitis (ORad  = 1.22, 95% CI = 1.02-1.46; ORad  = 1.40, 95% CI = 1.04-1.89, respectively) while moderate and vigorous recreational PAs were correlated with lower odds of periodontitis (ORad  = 0.81, 95% CI = 0.69-0.95; ORad  = 0.55, 95% CI = 0.43-0.71, respectively).

CONCLUSIONS

Work PAs and recreational PAs have opposite associations on the prevalence of developing periodontitis and their aggravating or protective associations enhance with the increase of intensity.

Associations between Pre-Diagnostic Physical Activity with Breast Cancer Characteristics and Survival

Physical activity (PA) is known to reduce breast cancer (BC) risk and improve patient prognosis. However, the association between pre-diagnostic PA and the aggressiveness of BC is unclear. We investigated the associations between PA, BC tumour characteristics, and survival. This retrospective observational study included 7688 BC patients from the Singapore Breast Cancer Cohort (2010−2016). PA information from the questionnaire included intensity (light/moderate/vigorous) and duration (<1 h/1−2 h/>2 h per week). A PA score (1−5) incorporating intensity and duration was calculated. Associations between PA score and tumour characteristics such as stage, histological grade, nodal and hormone receptor status were examined using multinomial regression. Moreover, 10-year overall survival was estimated using Cox regression analysis in 6572 patients after excluding patients with invalid survival data and stage IV disease. Breast tumours associated with higher PA score were more likely to be non-invasive (ORinvasive vs. non-invasive(reference) [95% CI]: 0.71 [0.58−0.87], p-trend = 0.001), of lower grade (ORpoorly vs. well differentiated(reference): 0.69 [0.52−0.93], p = 0.014), ER-positive (ORER-negative vs. ER-positive(reference): 0.94 [0.89−1.00], p-trend = 0.049), PR-positive (ORPR-negative vs. PR-positive(reference): 0.82 [0.67−0.99], p = 0.041), HER2-negative (ORHER2-negative vs. HER2-positive(reference): 1.29 [1.02−1.62], p-trend = 0.002), and less likely to be of HER2-overexpressed subtype (ORHER2-overexpressed vs. Luminal A(reference): 0.89 [0.81−0.98], p-trend = 0.018). These associations (odds ratios) were more pronounced among post-menopausal patients. A higher PA score did not improve survival. Higher levels of pre-diagnostic PA were associated with less aggressive tumours in BC patients. This illustrated another benefit of PA in addition to its known role in BC risk reduction.

Leisure-time physical activity, sedentary behavior, and risk of breast cancer: Results from the SUN ('Seguimiento Universidad De Navarra') project

Evidence is still limited on the influence of sedentary lifestyles on breast cancer (BC) risk. Also, prospective information on the combined effects of both sedentariness and leisure-time physical activity (LTPA) is scarce. We aimed to assess the association of higher sedentary behavior and LTPA (separately and in combination) with the risk of BC in a middle-aged cohort of university graduates. The SUN Project is a follow-up study initiated in 1999 with recruitment permanently open. Baseline assessments included a validated questionnaire on LTPA and sedentary habits. Subsequently, participants completed biennial follow-up questionnaires. Multivariable adjusted Cox models were used to estimate the hazard ratios (HR) for incident BC according to LTPA, TV-watching, the joint classification of both, and a combined 8-item multidimensional active lifestyle score. We included 10,812 women, with 11.8 years of median follow-up of. Among 115,802 women-years of follow-up, we confirmed 101 incident cases of BC. Women in the highest category of LTPA (>16.5 MET-h/week) showed a significantly lower risk of BC (HR = 0.55; 95% CI: 0.34-0.90) compared to women in the lowest category (≤6 MET/h-week). Women watching >2 h/d of TV sh owed a higher risk (HR = 1.67; 95% CI:1.03-2.72) than those who watched TV <1 h/d. Women in the highest category (6-8 points) of the multidimensional combined 8-item score showed a lower BC risk (HR = 0.35; 95% CI: 0.15-0.79) than those in the lowest category (<2 points) group. There was no significant supra-multiplicative interaction between TV-watching and LTPA. Both low LTPA and TV-watching >2 h/d may substantially increase BC risk, independently of each other.