The effects of weight loss and metformin on cognition among breast cancer survivors: Evidence from the Reach for Health study.

OBJECTIVE: Breast cancer survivors experience problems with cognition that interfere with daily life and can last for years. In the general population, obesity and diabetes are risk factors for cognitive decline, and weight loss can improve cognition; however, the impact of intentional weight loss on cancer survivors' cognition has not been tested. We investigated the impact of weight loss and metformin on changes in cognitive function in a sample of breast cancer survivors. METHODS: Overweight/obese postmenopausal breast cancer survivors (n = 333) were randomized to a weight loss intervention versus control and metformin versus placebo in a 2 × 2 factorial design. Outcomes were changes in five cognitive domains from baseline to 6 months measured by objective neurocognitive tests. RESULTS: There were no statistically significant intervention effects for the metformin or weight loss interventions in five neurocognitive domains. Baseline body mass index (BMI) was a significant effect modifier of the changes in verbal functioning for the weight loss (P = 0.009) and metformin interventions (P = 0.0125). These effect modifications were independent of percent weight loss achieved during the 6-month study period. CONCLUSIONS: This randomized controlled trial of weight loss and metformin interventions that examined changes to cognition among breast cancer survivors suggests that these interventions may not improve cognitive functioning among breast cancer survivors in general. However, weight loss may improve verbal functioning among individuals with a higher BMI.

Randomized controlled trial of increasing physical activity on objectively measured and self-reported cognitive functioning among breast cancer survivors: The memory & motion study.

BACKGROUND: Increasing physical activity can improve cognition in healthy and cognitively impaired adults; however, the benefits for cancer survivors are unknown. The current study examined a 12-week physical activity intervention, compared with a control condition, on objective and self-reported cognition among breast cancer survivors. METHODS: Sedentary breast cancer survivors were randomized to an exercise arm (n = 43) or a control arm (n = 44). At baseline and at 12 weeks, objective cognition was measured with the National Institutes of Health Cognitive Toolbox, and self-reported cognition using the Patient-Reported Outcomes Measurement Information System scales. Linear mixed-effects regression models tested intervention effects for changes in cognition scores. RESULTS: On average, participants (n = 87) were aged 57 years (standard deviation, 10.4 years) and were 2.5 years (standard deviation, 1.3 years) post surgery. Scores on the Oral Symbol Digit subscale (a measure of processing speed) evidenced differential improvement in the exercise arm versus the control arm (b = 2.01; P < .05). The between-group differences in improvement on self-reported cognition were not statistically significant but were suggestive of potential group differences. Time since surgery moderated the correlation, and participants who were ≤2 years post surgery had a significantly greater improvement in Oral Symbol Digit score (exercise vs control (b = 4.00; P < .01), but no significant improvement was observed in patients who were >2 years postsurgery (b = -1.19; P = .40). A significant dose response was observed with greater increased physical activity associated with objective and self-reported cognition in the exercise arm. CONCLUSIONS: The exercise intervention significantly improved processing speed, but only among those who had been diagnosed with breast cancer within the past 2 years. Slowed processing speed can have substantial implications for independent functioning, supporting the potential importance of early implementation of an exercise intervention among patients with breast cancer. Cancer 2018;124:192-202. © 2017 American Cancer Society.

Metabolic Effects of Intermittent Fasting.

The objective of this review is to provide an overview of intermittent fasting regimens, summarize the evidence on the health benefits of intermittent fasting, and discuss physiological mechanisms by which intermittent fasting might lead to improved health outcomes. A MEDLINE search was performed using PubMed and the terms "intermittent fasting," "fasting," "time-restricted feeding," and "food timing." Modified fasting regimens appear to promote weight loss and may improve metabolic health. Several lines of evidence also support the hypothesis that eating patterns that reduce or eliminate nighttime eating and prolong nightly fasting intervals may result in sustained improvements in human health. Intermittent fasting regimens are hypothesized to influence metabolic regulation via effects on (a) circadian biology, (b) the gut microbiome, and (c) modifiable lifestyle behaviors, such as sleep. If proven to be efficacious, these eating regimens offer promising nonpharmacological approaches to improving health at the population level, with multiple public health benefits.

Sleep duration and breast cancer prognosis: perspectives from the Women's Healthy Eating and Living Study.

PURPOSE: To examine whether baseline sleep duration or changes in sleep duration are associated with breast cancer prognosis among early-stage breast cancer survivors in the multi-center Women's Healthy Eating and Living Study. METHODS: Data were collected from 1995 to 2010. Analysis included 3047 women. Sleep duration was self-reported at baseline and follow-up intervals. Cox proportional hazard models were used to investigate whether baseline sleep duration was associated with breast cancer recurrence, breast cancer-specific mortality, and all-cause mortality. Time-varying models investigated whether changes in sleep duration were associated with breast cancer prognosis. RESULTS: Compared to women who slept 7-8 h/night at baseline, sleeping ≥9 h/night was associated with a 48% increased risk of breast cancer recurrence (Hazard ratio [HR] 1.48, 95% Confidence interval [CI] 1.01, 2.00), a 52% increased risk of breast cancer-specific mortality (HR 1.52, 95% CI 1.09, 2.13), and a 43% greater risk of all-cause mortality (HR 1.43, 95% CI 1.07, 1.92). Time-varying models showed analogous increased risk in those who inconsistently slept ≥9 h/night (all P < 0.05), but not in those who consistently slept ≥9 h/night. CONCLUSIONS: Consistent long or short sleep, which may reflect inter-individual variability in the need for sleep, does not appear to influence prognosis among early-stage breast cancer survivors.

Objectively measured sedentary behavior and quality of life among survivors of early stage breast cancer.

PURPOSE: This study examined relationships between sedentary behavior accumulated in different bout durations and quality of life (QoL) among breast cancer survivors. METHODS: Postmenopausal breast cancer survivors completed the Short Form Health Survey to assess QoL and wore an accelerometer to measure sedentary behavior and physical activity between August 2011 and May 2013. RESULTS: Participants (n = 134) averaged 509.7 min/day in sedentary time with 285.2 min/day in short bouts (<20 min) and 224.5 min/day long bouts (≥20 min). Linear regression models indicated that greater total sedentary time was significantly associated with worse physical QoL (b = -0.70, p = 0.02) but not mental QoL (p = 0.92). Models that examined the accumulation of sedentary time in short bouts and long bouts together showed that time in long sedentary bouts was significantly related to physical QoL (b = -0.72, p = 0.02), while time in short bouts was not (p = 0.63). Moderate-to-vigorous intensity physical activity (MVPA) was a significant effect modifier of the relation between time spent in long sedentary bouts and physical QoL (p = 0.028) such that greater time in long bouts was associated with worse physical QoL only among women with lower levels of MVPA. CONCLUSIONS: Findings indicate that time spent in long sedentary bouts is associated with worse physical QoL among breast cancer survivors who do not engage in high levels of MVPA. Future research should examine reducing sedentary time as a potential strategy to improve physical QoL.

A pooled analysis of post-diagnosis lifestyle factors in association with late estrogen-receptor-positive breast cancer prognosis.

Lifestyle factors have been well studied in relation to breast cancer prognosis overall; however, associations of lifestyle and late outcomes (>5 years after diagnosis) have been much less studied, and no studies have focused on estrogen receptor-positive (ER+) breast cancer survivors, who may have high risk of late recurrence and mortality. We utilized a large prospective pooling study to evaluate the associations of lifestyle factors with late recurrence and all-cause mortality among 6,295 5-year ER+ Stage I-III breast cancer survivors. Pooled and harmonized data were available on clinical factors and lifestyle factors (pre- to post-diagnosis weight change, body mass index (BMI) (kg/m(2)), recreational physical activity, alcohol intake and smoking history), measured on average 2.1 years after diagnosis. Updated information for weight only was available. Study heterogeneity was evaluated by the Q-statistic. Multivariable Cox regression models were stratified by study. Adjusting for clinical factors and potential confounders, ≥ 10% weight gain and obesity (BMI, 30-34.99 and ≥ 35) were associated with increased risk of late recurrence (hazard ratios (95% confidence intervals): 1.24 (1.00-1.53), 1.40 (1.05-1.86) and 1.41 (1.02-1.93), respectively). Daily alcohol intake was associated with late recurrence, 1.28 (1.01-1.62). Physical activity was inversely associated with late all-cause mortality (0.81 (0.71-0.93) and 0.71 (0.61-0.82) for 4.9 to <17.4 and ≥ 17.4 metabolic equivalent-hr/week). A U-shaped association was observed for late all-cause mortality and BMI using updated weight (1.42 (1.15-1.74) and 1.40 (1.09-1.81), <21.5 and ≥ 35, respectively). Smoking was associated with increased risk of late outcomes. In this large prospective pooling project, modifiable lifestyle factors were associated with late outcomes among long-term ER+ breast cancer survivors.

Impact of very low physical activity, BMI, and comorbidities on mortality among breast cancer survivors.

The purpose of this study was to examine post-diagnosis BMI, very low physical activity, and comorbidities, as predictors of breast cancer-specific and all-cause mortality. Data from three female US breast cancer survivor cohorts were harmonized in the After Breast Cancer Pooling Project (n = 9513). Delayed entry Cox proportional hazards models were used to examine the impact of three post-diagnosis lifestyle factors: body mass index (BMI), select comorbidities (diabetes only, hypertension only, or both), and very low physical activity (defined as physical activity <1.5 MET h/week) in individual models and together in multivariate models for breast cancer and all-cause mortality. For breast cancer mortality, the individual lifestyle models demonstrated a significant association with very low physical activity but not with the selected comorbidities or BMI. In the model that included all three lifestyle variables, very low physical activity was associated with a 22 % increased risk of breast cancer mortality (HR 1.22, 95 % CI 1.05, 1.42). For all-cause mortality, the three individual models demonstrated significant associations for all three lifestyle predictors. In the combined model, the strength and significance of the association of comorbidities (both hypertension and diabetes versus neither: HR 2.16, 95 % CI 1.79, 2.60) and very low physical activity (HR 1.35, 95 % CI 1.22, 1.51) remained unchanged, but the association with obesity was completely attenuated. These data indicate that after active treatment, very low physical activity, consistent with a sedentary lifestyle (and comorbidities for all-cause mortality), may account for the increased risk of mortality, with higher BMI, that is seen in other studies.

Randomized trial of a phone- and web-based weight loss program for women at elevated breast cancer risk: the HELP study.

Excess weight and physical inactivity are modifiable risk factors for breast cancer. Behavioral intervention is particularly important among women with an elevated risk profile. This trial tested an intervention that trained women to use a self-monitoring website to increase activity and lose weight. Women with BMI ≥27.5 kg/m(2) at elevated breast cancer risk were randomized to the intervention (N = 71) or usual care (N = 34). The intervention group received telephone-based coaching and used web-based self-monitoring tools. At 6 months, significant weight loss was observed in the intervention group (4.7 % loss from starting weight; SD = 4.7 %) relative to usual care (0.4 % gain; SD = 3.0 %) (p < 0.0001). By 12 months, the intervention group had lost 3.7 % of weight (SD = 5.4 %), compared to 1.3 % (SD = 4.2) for usual care (p = 0.003). At 12 months, accelerometer-measured moderate-to-vigorous physical activity increased by 12 min/day (SD = 24) compared to no change in usual care (p = 0.04. In summary, this web- and phone-based approach produced modest but significant improvements in weight and physical activity for women at elevated breast cancer risk.

Lifestyle factors associated with cognitive functioning in breast cancer survivors.

OBJECTIVE: Weight, physical activity, and sleep are modifiable lifestyle factors that impact cognitive functioning in noncancer populations but have yet to be examined in cancer survivors. The aim of the study was to assess the relationship of obesity, physical activity, and sleep, with cognitive functioning among breast cancer survivors. METHODS: Participants were 136 early-stage postmenopausal breast cancer survivors who completed an assessment of neuropsychological testing, height, weight, physical activity, and sleep. Linear regression models examined the associations of the seven neuropsychological domains with obesity, physical activity, and sleep. Logistic regression models examined odd of impairment in each domain. All models controlled for breast cancer treatment variables and relevant demographic and clinical variables. RESULTS: Obese participants had significantly worse performance (ß = -5.04, standard error (SE) = 2.53) and were almost three times more likely to be impaired (odds ratio (OR) = 2.87; 95% CI: 1.02-8.10) on the Information processing domain. The highest tertile of physical activity was significantly related to better performance on the executive functioning domain (ß = 5.13, SE = 2.42) and attention domain (ß = 4.26, SE = 2.07). The middle tertile of physical activity was significantly related to better performance (ß = 9.00, SE = 3.09) and decreased odds of impairment (OR = 0.89, 95% CI: 0.07-0.91) on the visual-spatial domain. More hours of sleep per night was significantly associated with better performance (ß = 2.69, SE = 0.98) and decreased odds of impairment (OR = 0.52; 95% CI: 0.33-0.82) on the verbal functioning domain. CONCLUSIONS: These findings suggest that obesity, physical activity, and sleep are related to cognitive functioning among breast cancer survivors and have potential to be intervention targets to improve cognitive functioning.

Short sleep duration is associated with higher energy intake and expenditure among African-American and non-Hispanic white adults.

Habitual short sleep duration appears to increase the risk of obesity. The objective of this paper is to investigate the association of habitual sleep duration with objective measures of energy balance. One hundred twelve African-American and 111 non-Hispanic whites aged 21-69 y participated in a cross-sectional study of dietary assessment and biomarkers. Participants reported the mean number of hours per day spent sleeping over the past year. Short sleep duration was defined as ≤6 h/d of sleep. Energy intake (kilocalories) was objectively assessed using the 2-point doubly labeled water technique to determine total energy expenditure, which is approximately equal to energy intake. Physical activity energy expenditure (kilocalories) was estimated as total energy expenditure minus each participant's calculated basal metabolic rate and the thermogenic effect of food. Compared with participants who slept ≤6 h, individuals who slept 8 h were significantly less likely to be obese (OR: 0.33; 95% CI: 0.14, 0.79). However, this association was not linear across 6-9 h of sleep (P-trend = 0.16). There was an inverse association between sleep and energy intake (P-trend = 0.07): compared with ≤6 h/d, adults who reported ≥9 h sleep consumed 178 fewer kcal/d. There was also an inverse association between sleep and physical activity (P-trend = 0.05): compared with ≤6 h/d of sleep, adults who reported 9 h of usual sleep expended 113 fewer kcal/d in physical activity. These data indicate that, compared with longer sleep duration, adults who report habitual short sleep duration have somewhat higher physical activity energy expenditure but considerably higher energy intake. Habitual short sleep duration appears to be 1 of the facets of modern life leading to a mismatch between energy intake and physical activity.

The 2011-2016 Transdisciplinary Research on Energetics and Cancer (TREC) initiative: rationale and design.

PURPOSE: Recognition of the complex, multidimensional relationship between excess adiposity and cancer control outcomes has motivated the scientific community to seek new research models and paradigms. METHODS: The National Cancer Institute developed an innovative concept to establish a center grant mechanism in nutrition, energetics, and physical activity, referred to as the Transdisciplinary Research on Energetics and Cancer (TREC) Initiative. This paper gives an overview of the 2011-2016 TREC Collaborative Network and the 15 research projects being conducted at the centers. RESULTS: Four academic institutions were awarded TREC center grants in 2011: Harvard University, University of California San Diego, University of Pennsylvania, and Washington University in St. Louis. The Fred Hutchinson Cancer Research Center is the Coordination Center. The TREC research portfolio includes three animal studies, three cohort studies, four randomized clinical trials, one cross-sectional study, and two modeling studies. Disciplines represented by TREC investigators include basic science, endocrinology, epidemiology, biostatistics, behavior, medicine, nutrition, physical activity, genetics, engineering, health economics, and computer science. Approximately 41,000 participants will be involved in these studies, including children, healthy adults, and breast and prostate cancer survivors. Outcomes include biomarkers of cancer risk, changes in weight and physical activity, persistent adverse treatment effects (e.g., lymphedema, urinary and sexual function), and breast and prostate cancer mortality. CONCLUSION: The NIH Science of Team Science group will evaluate the value added by this collaborative science. However, the most important outcome will be whether this transdisciplinary initiative improves the health of Americans at risk of cancer as well as cancer survivors.

Web-based self-monitoring for weight loss among overweight/obese women at increased risk for breast cancer: the HELP pilot study.

OBJECTIVE: Excess weight and physical inactivity are modifiable risk factors for breast cancer. Training women to use self-help resources over the internet has potential for reducing intervention costs and enhancing maintenance. METHODS: A total of 50 overweight/obese women at increased breast cancer risk were randomized to a 12-week intervention or a comparison group. Telephone-based sessions trained participants to use web-based self-monitoring tools to set goals and track diet and exercise. The comparison group received dietary information but no training. At baseline and 12 weeks, participants were weighed and wore an accelerometer. RESULTS: Participants were aged 60.9 ± 0.8 years with a BMI of 33.1 ± 0.6 kg/m(2). The intervention group lost 3.3 ± 4.0 kg, whereas the comparison group gained 0.9 ± 3.4 kg (p < 0.0001). Intervention participants who found the website helpful lost 5.6 ± 0.7 kg; those who did not lost 0.8 ± 0.9 kg (p < 0.001). Change in physical activity was +70 ± 140 min/week among those who found the website helpful, -6 ± 75 min/week among those who did not, and -34 ± 207 min/week in the comparison group (p < 0.01). CONCLUSIONS: A program to train women to use web-based weight loss tools achieved a substantial short-term weight loss among the majority of participants. Further follow-up is needed to assess weight loss maintenance over time.

Meeting the physical activity guidelines and survival after breast cancer: findings from the after breast cancer pooling project.

The 2008 Physical Activity (PA) Guidelines recommend engaging in at least 2.5 h (10 MET-hours/week) of moderate intensity PA per week (defined as 4 METs) to reduce risk of morbidity and mortality. This analysis was conducted to investigate whether this recommendation can be extended to breast cancer survivors. Data from four studies of breast cancer survivors measuring recreational PA from semi-quantitative questionnaires a median of 23 months post-diagnosis (interquartile range 18-32 months) were pooled in the After Breast Cancer Pooling Project (n = 13,302). Delayed entry Cox proportional hazards models were applied in data analysis with adjustment for age, post-diagnosis body mass index, race/ethnicity, menopausal status, TNM stage, cancer treatment, and smoking history. Engaging in at least 10 MET-hours/week of PA was associated with a 27% reduction in all-cause mortality (n = 1,468 events, Hazard Ratio (HR) = 0.73, 95% CI, 0.66-0.82) and a 25% reduction in breast cancer mortality (n = 971 events, HR = 0.75, 95% CI 0.65-0.85) compared with women who did not meet the PA Guidelines (<10 MET-hours/week). Risk of breast cancer recurrence (n = 1,421 events) was not associated with meeting the PA Guidelines (HR = 0.96, 95% CI, 0.86-1.06). These data suggest that adhering to the PA guidelines may be an important intervention target for reducing mortality among breast cancer survivors.

Non-steroidal anti-inflammatory drugs and cancer incidence by sex in the VITamins And Lifestyle (VITAL) cohort.

PURPOSE: Use of non-steroidal anti-inflammatory drugs (NSAIDs) may reduce the incidence of several cancers. A recent meta-analysis of randomized trials of aspirin reported a reduction in cancer mortality; however, few studies have investigated whether aspirin or other NSAIDs reduce overall cancer risk. METHODS: 64,847 residents of western Washington State, aged 50-76, completed a baseline questionnaire in 2000-2002 and reported on their use of individual NSAIDs over the past 10 years. Behavior was categorized as non-use, low (<4 days/week or <4 years), and high (≥4 days/week and ≥4 years). Over 7 years of follow-up, 5,946 incident invasive cancer cases were identified. Multivariable proportional hazards models were used to estimate hazard ratios (HR) and 95% confidence intervals (CI). RESULTS: Relative to non-use, high 10-year use of regular-strength NSAIDs was inversely associated with total cancer risk in men (HR 0.88, 95% CI: 0.79-0.97) and not associated with risk in women (HR 1.10, 95% CI: 0.96-1.25; p interaction <0.01). Use of regular-strength NSAIDs was strongly and inversely associated with colorectal cancer risk in men and women, but differentially associated with sex-specific risk of shared cancer sites other than colorectal cancer (men: HR 0.83, 95% CI: 0.71-0.97; women: HR 1.18, 95% CI: 0.97-1.44; p interaction < 0.01). CONCLUSIONS: Long-term use of NSAIDs was associated with a reduced risk of total cancer among men and colorectal cancer among both sexes. Our findings do not support NSAID use for overall cancer prevention among women. Additional high-quality studies with long-term follow-up for cancer among women are needed before a public health recommendation can be made.

Dietary intake of specific fatty acids and breast cancer risk among postmenopausal women in the VITAL cohort.

Studies of dietary fat intake and breast cancer have been inconsistent and few have examined specific fatty acids. We examined the association between specific monounsaturated (MUFA), polyunsaturated (PUFA), saturated (SFA), and trans-fatty acids (TFA) and breast cancer risk. Participants, 50-76 yr, were female members of the VITamins And Lifestyle (VITAL) Cohort, who were postmenopausal at baseline. In 2000-2002, participants completed a food frequency questionnaire. Seven hundred seventy-two incident, primary breast cancer cases were identified using a population-based cancer registry. Cox proportional hazard models estimated hazard ratios (HR) and 95% confidence intervals (95% CI) for the association between fatty acid intake and breast cancer risk. Intake of total MUFAs (highest vs. lowest quintile: HR = 1.61, 95% CI: 1.08-2.38, P trend = 0.02), particularly myristoleic and erucic acids, was associated with increased breast cancer risk. Whereas total SFA was suggestive of an increased risk (HR = 1.47, 95% CI: 1.00-2.15, P trend = 0.09), strong associations were observed for palmitic, margaric, and stearic acids. Total TFA and PUFA intake were not associated with breast cancer. However, among TFAs, linolelaidic acid was positively associated with risk; among PUFAs, intake of eicosapentaenoic and docosahexaenoic acids were inversely associated with risk. Our findings show that fatty acids are heterogeneous in their association with postmenopausal breast cancer risk.

Hematopoietic prostaglandin D synthase (HPGDS): a high stability, Val187Ile isoenzyme common among African Americans and its relationship to risk for colorectal cancer.

Intestinal tumors in Apc(Min/+) mice are suppressed by over-production of HPGDS, which is a glutathione transferase that forms prostaglandin D(2) (PGD(2)). We characterized naturally occurring HPGDS isoenzymes, to see if HPGDS variation is associated with human colorectal cancer risk. We used DNA heteroduplex analysis and sequencing to identify HPGDS variants among healthy individuals. HPGDS isoenzymes were produced in bacteria, and their catalytic activities were tested. To determine in vivo effects, we conducted pooled case-control analyses to assess whether there is an association of the isoenzyme with colorectal cancer. Roughly 8% of African Americans and 2% of Caucasians had a highly stable Val187lle isoenzyme (with isoleucine instead of valine at position 187). At 37°C, the wild-type enzyme lost 15% of its activity in 1h, whereas the Val187Ile form remained >95% active. At 50°C, the half life of native HPGDS was 9min, compared to 42 min for Val187Ile. The odds ratio for colorectal cancer among African Americans with Val187Ile was 1.10 (95% CI, 0.75-1.62; 533 cases, 795 controls). Thus, the Val187Ile HPGDS isoenzyme common among African Americans is not associated with colorectal cancer risk. Other approaches will be needed to establish a role for HPGDS in occurrence of human intestinal tumors, as indicated by a mouse model.

Improvement in self-reported physical health predicts longer survival among women with a history of breast cancer.

Physical health-related quality of life scores have been, inconsistently, associated with breast cancer prognosis. This analysis examined whether change in physical health scores were related to outcomes in women with a history of breast cancer. 2343 breast cancer survivors in a randomized diet trial provided self-reported assessment of physical health-related quality of life at baseline and year 1. Based on change in physical health score, participants were grouped into subpopulations of decreased physical health, no/minimal changes, and increased physical health. Cox regression analysis assessed whether change in physical health (from baseline to year 1) predicted disease-free and overall survival; hazard ratio (HR) was the measure of association. There were 294 additional breast cancer events and 162 deaths among women followed for 7.3 years. Improvements in physical health were associated with younger age, lower BMI, being employed, not receiving tamoxifen, lower physical activity, and lower baseline physical and mental health. There was no association of change in physical health with additional breast cancer events or mortality among women diagnosed ≤ 2 years before study enrollment. However, among women who entered the study >2 years post-diagnosis, the HR for increased compared to decreased physical health was 0.38 (95% CI, 0.16-0.85) for all-cause mortality. These results appear to support testing an intervention to improve physical health in breast cancer patients among patients after the acute stage of treatment.

The After Breast Cancer Pooling Project: rationale, methodology, and breast cancer survivor characteristics.

The After Breast Cancer Pooling Project was established to examine the role of physical activity, adiposity, dietary factors, supplement use, and quality of life (QOL) in breast cancer prognosis. This paper presents pooled and harmonized data on post-diagnosis lifestyle factors, clinical prognostic factors, and breast cancer outcomes from four prospective cohorts of breast cancer survivors (three US-based and one from Shanghai, China) for 18,314 invasive breast cancer cases diagnosed between 1976 and 2006. Most participants were diagnosed with stage I-II breast cancer (84.7%). About 60% of breast tumors were estrogen receptor (ER)+/progesterone receptor (PR)+; 21% were ER-/PR-. Among 8,118 participants with information on HER-2 tumor status, 74.8% were HER-2- and 18.5% were HER-2+. At 1-2 years post-diagnosis (on average), 17.9% of participants were obese (BMI ≥ 30 kg/m2), 32.6% were overweight (BMI 25-29 kg/m2), and 59.9% met the 2008 Physical Activity Guidelines for Americans (≥ 2.5 h per week of moderate activity). During follow-up (mean = 8.4 years), 3,736 deaths (2,614 from breast cancer) and 3,564 recurrences have been documented. After accounting for differences in year of diagnosis and timing of post-diagnosis enrollment, five-year overall survival estimates were similar across cohorts. This pooling project of 18,000 breast cancer survivors enables the evaluation of associations of post-diagnosis lifestyle factors, QOL, and breast cancer outcomes with an adequate sample size for investigation of heterogeneity by hormone receptor status and other clinical predictors. The project sets the stage for international collaborations for the investigation of modifiable predictors for breast cancer outcomes.

Physical activity, additional breast cancer events, and mortality among early-stage breast cancer survivors: findings from the WHEL Study.

OBJECTIVE: Research suggests that physical activity is associated with improved breast cancer survival, yet no studies have examined the association between post-diagnosis changes in physical activity and breast cancer outcomes. The aim of this study was to determine whether baseline activity and 1-year change in activity are associated with breast cancer events or mortality. METHODS: A total of 2,361 post-treatment breast cancer survivors (Stage I-III) enrolled in a randomized controlled trial of dietary change completed physical activity measures at baseline and one year. Physical activity variables (total, moderate-vigorous, and adherence to guidelines) were calculated for each time point. Median follow-up was 7.1 years. Outcomes were invasive breast cancer events and all-cause mortality. RESULTS: Those who were most active at baseline had a 53% lower mortality risk compared to the least active women (HR = 0.47; 95% CI: 0.26, 0.84; p = .01). Adherence to activity guidelines was associated with a 35% lower mortality risk (HR = 0.65, 95% CI: 0.47, 0.91; p < .01). Neither baseline nor 1-year change in activity was associated with additional breast cancer events. CONCLUSIONS: Higher baseline (post-treatment) physical activity was associated with improved survival. However, change in activity over the following year was not associated with outcomes. These data suggest that long-term physical activity levels are important for breast cancer prognosis.

Marine fatty acid intake is associated with breast cancer prognosis.

EPA and DHA, long-chain (n-3) PUFA largely obtained from fish, inhibit the proliferation of breast cancer cells in vitro and reduce the initiation and progression of breast tumors in laboratory animals. Our purpose in this analysis was to examine whether intake of these marine fatty acids (EPA and DHA) were associated with prognosis in a cohort of women who had been diagnosed and treated for early stage breast cancer (n = 3,081). Median follow-up was 7.3 y. Dietary intake was assessed using 24-h recalls (~4 recalls per dietary assessment obtained at 7 time points over 6 y). Survival models with time-dependent covariates were used to examine the association of repeated measures of dietary intake of EPA and DHA from food (i.e., marine sources) and supplements with disease-free survival and overall survival. Women with higher intakes of EPA and DHA from food had an approximate 25% reduced risk of additional breast cancer events [tertile 2: HR = 0.74 (95% CI = 0.58-0.94); tertile 3: HR = 0.72 (95% CI = 0.57-0.90)] compared with the lowest tertile of intake. Women with higher intakes of EPA and DHA from food had a dose-dependent reduced risk of all-cause mortality [tertile 2: HR = 0.75 (95% CI = 0.55-1.04); tertile 3: HR = 0.59 (95% CI = 0.43-0.82)]. EPA and DHA intake from fish oil supplements was not associated with breast cancer outcomes. The investigation indicates that marine fatty acids from food are associated with reduced risk of additional breast cancer events and all-cause mortality.