Physical Activity and Breast Cancer Survival-Epidemiologic Evidence and Potential Biologic Mechanisms.

PURPOSE OF REVIEW: To review the biologic mechanisms that may be operative between physical activity and survival after breast cancer. RECENT FINDINGS: Physical activity decreases risk of mortality from breast cancer by up to 40%. Several biologic mechanisms have been hypothesized to explain this association. Previous cohort studies and randomized trials have examined the primary mechanisms that appear to be operative, which involve a decrease in sex hormone levels, insulin resistance, and inflammation. The evidence is still inconsistent and several limitations in the existing literature exist. Understanding the biologic mechanisms involved in the association of physical activity and breast cancer survival will provide more precision to physical activity guidelines for cancer survival. To achieve this objective, future research should include direct measurements of physical activity, sedentary behaviour, and health-related fitness to provide a more comprehensive assessment of these factors and their association with biomarkers and survival after breast cancer.

Life-Space Mobility and Parkinson's Disease. A Multiple-Methods Study.

Background: Life-space mobility (LSM) captures a broad spectrum of mobility in physical and social environments; however, it has not been extensively studied in Parkinson's disease. Using a multiple-methods approach, individual, social and environmental factors that impact LSM were explored in PD. Methods: Two hundred twenty-seven participants with PD (n = 113) and a comparative group without PD (n = 114) were recruited from the community. Within a cross-sectional survey, LSM (University of Alabama Birmingham Life-Space Assessment, LSA) was compared in the two groups. Using multiple linear regression, socio-demographics, lifestyle behaviors, medical, mobility and social factors were examined to identify factors that explained LSM. A qualitative narrative inquiry was completed to augment the findings from the survey; 10 participants with PD were interviewed regarding facilitators and barriers to mobility. Results: The mean overall LSA-composite score for the PD group was 64.2 (SD = 25.8) and 70.3 (SD = 23.1) for the community comparative group (mean difference = 6 points, 95%CI:-0.4, 12.5) indicating most participants moved independently beyond their neighborhoods. A higher proportion of the PD group required assistance with mobility than the community comparison group. Not driving, receiving caregiving, lower social participation, and lower monthly family finances were associated with restricted LSM in the PD group. Data from qualitative interviews supported quantitative findings and offered insights into the features of the built environment that facilitate and restrict mobility. Conclusion: Individual, social and environmental factors are associated with the LSM among persons with PD. Clinicians and policy-makers should include both individual and community-based factors when developing interventions to encourage the LSM of the PD population.

The Alberta moving beyond breast cancer (AMBER) cohort study: baseline description of the full cohort.

PURPOSE: The Alberta Moving Beyond Breast Cancer (AMBER) Study is an ongoing prospective cohort study investigating how direct measures of physical activity (PA), sedentary behavior (SB), and health-related fitness (HRF) are associated with survival after breast cancer. METHODS: Women in Alberta with newly diagnosed stage I (≥ T1c) to IIIc breast cancer were recruited between 2012 and 2019. Baseline assessments were completed within 90 days of surgery. Measurements included accelerometers to measure PA and SB; a graded treadmill test with gas exchange analysis to measure cardiorespiratory fitness (VO2peak); upper and lower body muscular strength and endurance; dual-X-ray absorptiometry to measure body composition; and questionnaires to measure self-reported PA and SB. RESULTS: At baseline, the 1528 participants' mean age was 56 ± 11 years, 59% were post-menopausal, 62% had overweight/obesity, and 55% were diagnosed with stage II or III disease. Based on device measurements, study participants spent 8.9 ± 1.7 h/day sedentary, 4.4 ± 1.2 h/day in light-intensity activity, 0.9 ± 0.5 h/day in moderate-intensity activity, and 0.2 ± 0.2 h/day in vigorous-intensity activity. For those participants who reached VO2peak, the average aerobic fitness level was 26.6 ± 6 ml/kg/min. Average body fat was 43 ± 7.1%. CONCLUSION: We have established a unique cohort of breast cancer survivors with a wealth of data on PA, SB, and HRF obtained through both direct and self-reported measurements. Study participants are being followed for at least ten years to assess all outcomes after breast cancer. These data will inform clinical and public health guidelines on PA, SB, and HRF for improving breast cancer outcomes.

The Burden of Late Effects and Related Risk Factors in Adolescent and Young Adult Cancer Survivors: A Scoping Review.

Risk factors associated with late effects in survivors of adolescent and young adult (AYA) cancer are poorly understood. We conducted a systematic scoping review to identify cohort studies published in English from 2010-2020 that included: (1) cancer survivors who were AYAs (age 15-39 years) at diagnosis and (2) outcomes of subsequent malignant neoplasms (SMNs), chronic conditions, and/or late mortality (>5 years postdiagnosis). There were 652 abstracts identified and, ultimately, 106 unique studies were included, of which 23, 34, and 54 studies related to the risk of SMNs, chronic conditions, and mortality, respectively. Studies investigating late effects among survivors of any primary cancer reported that AYA cancer survivors were at higher risk of SMN, chronic conditions, and all-cause mortality compared to controls. There was an indication that the following factors increased risk: radiation exposure (n = 3) for SMNs; younger attained age (n = 4) and earlier calendar period of diagnosis (n = 3) for chronic conditions; and non-Hispanic Black or Hispanic (n = 5), low socioeconomic status (n = 3), and earlier calendar period of diagnosis (n = 4) for late mortality. More studies including the full AYA age spectrum, treatment data, and results stratified by age, sex, and cancer type are needed to advance knowledge about late effects in AYA cancer survivors.

Physical activity, obesity and sedentary behavior in cancer etiology: epidemiologic evidence and biologic mechanisms.

An estimated 30-40% of cancers can be prevented through changes in modifiable lifestyle and environmental risk factors known to be associated with cancer incidence. Despite this knowledge, there remains limited awareness that these associations exist. The purpose of this review article was to summarize the epidemiologic evidence concerning the contribution of physical activity, sedentary behavior, and obesity to cancer etiology and to provide an overview of the biologic mechanisms that may be operative between these factors and cancer incidence. Strong and consistent evidence exists that higher levels of physical activity reduce the risk of six different cancer sites (bladder, breast, colon, endometrial, esophageal adenocarcinoma, gastric cardia), whereas moderate evidence inversely associates physical activity with lung, ovarian, pancreatic and renal cancer, and limited evidence inversely correlates physical activity with prostate cancer. Sedentary behavior, independent of physical activity, has been shown to increase the risk of colon, endometrial, and lung cancers. Obesity is an established risk factor for 13 different cancer sites (endometrial, postmenopausal breast, colorectal, esophageal, renal/kidneys, meningioma, pancreatic, gastric cardia, liver, multiple myeloma, ovarian, gallbladder, and thyroid). The main biologic mechanisms whereby physical activity, sedentary behavior, and obesity are related to cancer incidence include an effect on endogenous sex steroids and metabolic hormones, insulin sensitivity, and chronic inflammation. Several emerging pathways related to oxidative stress, DNA methylation, telomere length, immune function, and gut microbiome are presented. Key recommendations for future research in both the epidemiology and biology of the associations between physical activity, sedentary behavior, obesity, and cancer risk are also provided.

Prospective Cohort Study of Pre- and Postdiagnosis Physical Activity and Endometrial Cancer Survival.

PURPOSE: The aim of this study was to evaluate associations between pre- and postdiagnosis physical activity and survival in survivors of endometrial cancer by physical activity domain, intensity, dose (metabolic-equivalent task [MET]-hours/week/year), and change from pre- to postdiagnosis. METHODS: We conducted a prospective cohort study in Alberta, Canada, of 425 women who were diagnosed with histologically confirmed invasive endometrial cancer between 2002 and 2006 and observed to 2019. The interviewer-administered Lifetime Total Physical Activity Questionnaire recorded prediagnosis (assessed at a median of 4.4 months after diagnosis) and postdiagnosis physical activity (assessed at a median of 3.4 years after diagnosis). Associations between physical activity and overall and disease-free survival were assessed using Cox proportional hazards models adjusted for age, stage, grade, treatments, body mass index, menopausal status, hormone therapy use, family history of cancer, and comorbidities. RESULTS: After a median follow-up of 14.5 years, there were 60 deaths, including 18 endometrial cancer deaths, and 80 disease-free survival events. Higher prediagnosis recreational physical activity was statistically significantly associated with improved disease-free survival (> 14 v ≤ 8 MET-hours/week/year; hazard ratio [HR], 0.54; 95% CI, 0.30 to 0.96; Ptrend = .04), but not overall survival (HR, 0.56; 95% CI, 0.29 to 1.07; Ptrend = .06). Higher postdiagnosis recreational physical activity (> 13 v ≤ 5 MET-hours/week/year) was strongly associated with both improved disease-free survival (HR, 0.33; 95% CI, 0.17 to 0.64; Ptrend = .001) and overall survival (HR, 0.33; 95% CI, 0.15 to 0.75; Ptrend = .007). Participants who maintained high recreational physical activity levels from pre- to postdiagnosis also had improved disease-free survival (HR, 0.35; 95% CI, 0.18 to 0.69) and overall survival (HR, 0.43; 95% CI, 0.20 to 0.94) compared with those who maintained low physical activity levels. CONCLUSION: Recreational physical activity, especially postdiagnosis, is associated with improved survival in survivors of endometrial cancer.