Sustained Weight Loss and Risk of Breast Cancer in Women 50 Years and Older: A Pooled Analysis of Prospective Data.
ABSTRACT: BACKGROUND:Excess body weight is an established cause of postmenopausal breast cancer, but it is unknown if weight loss reduces risk. METHODS:Associations between weight change and risk of breast cancer were examined among women aged 50?years and older in the Pooling Project of Prospective Studies of Diet and Cancer. In 10 cohorts, weight assessed on three surveys was used to examine weight change patterns over approximately 10?years (interval 1 median = 5.2?years; interval 2 median = 4.0?years). Sustained weight loss was defined as no less than 2 kg lost in interval 1 that was not regained in interval 2. Among 180 885 women, 6930 invasive breast cancers were identified during follow-up. RESULTS:Compared with women with stable weight (±2?kg), women with sustained weight loss had a lower risk of breast cancer. This risk reduction was linear and specific to women not using postmenopausal hormones (>2-4.5?kg lost: hazard ratio [HR] = 0.82, 95% confidence interval [CI] = 0.70 to 0.96; >4.5-<9 kg lost: HR?=?0.75, 95% CI = 0.63 to 0.90; ?9 kg lost: HR?=?0.68, 95% CI = 0.50 to 0.93). Women who lost at least 9 kg and gained back some (but not all) of it were also at a lower risk of breast cancer. Other patterns of weight loss and gain over the two intervals had a similar risk of breast cancer to women with stable weight. CONCLUSIONS:These results suggest that sustained weight loss, even modest amounts, is associated with lower breast cancer risk for women aged 50?years and older. Breast cancer prevention may be a strong weight-loss motivator for the two-thirds of American women who are overweight or obese.
Project description:To examine prospectively the relationships of prepregnancy body mass index (BMI), BMI at age 18 years, and weight change since age 18 years with risk of fetal loss.Our prospective cohort study included 25,719 pregnancies reported by 17,027 women in the Nurses' Health Study II between 1990 and 2009. In 1989, height, current weight, and weight at age 18 years were self-reported. Current weight was updated every 2 years thereafter. Pregnancies were self-reported, with case pregnancies lost spontaneously and comparison pregnancies ending in ectopic pregnancy, induced abortion, or live birth.Incident fetal loss was reported in 4,494 (17.5%) pregnancies. Compared with those of normal BMI, the multivariate relative risks of fetal loss were 1.07 (95% CI [confidence interval] 1.00-1.15) for overweight women, 1.10 (95% CI 0.98-1.23) for class I obese women, and 1.27 (95% CI 1.11-1.45) for class II and class III obese women (P trend ? .001). Body mass index at age 18 years was not associated with fetal loss (P trend=.59). Compared with women who maintained a stable weight (± 4 kg) between age 18 years and before pregnancy, women who lost weight had a 20% (95% CI 9-29%) lower risk of fetal loss. This association was stronger among women who were overweight at age 18 years.Being overweight or obese before pregnancy was associated with higher risk of fetal loss. In women overweight or obese at age 18 years, losing 4 kg or more was associated with a lower risk of fetal loss.: II.
Project description:<h4>Background</h4>Adult weight gain is associated with increased risk of postmenopausal breast cancer. Most previous studies are limited by using recalled or self-reported data, and it is not known if age-specific weight changes are important for breast cancer risk.<h4>Methods</h4>In a Norwegian cohort of 28,153 women (and 900 incident breast cancers) with longitudinal anthropometric measurements over up to 30 years, we studied both overall and age-related weight changes in adulthood and risk of postmenopausal breast cancer.<h4>Results</h4>Overall, weight gain in adulthood was associated with increased breast cancer risk (hazard ratio (HR) per kg per year 1.31, 95% confidence interval (CI) 1.11-1.54). Weight gain before (HR per kg per year 1.38, 95% CI 1.09-1.75) or around menopause (1.69, 95% CI 1.32-2.16) was associated with increased risk, but there was no clear risk increase associated with later weight gain (HR per kg per year 0.92, 95% CI 0.73-1.18).<h4>Conclusion</h4>Weight gain in adulthood was associated with increased risk of breast cancer. Our results suggest that weight gain before and around menopausal age may be particularly important for breast cancer risk among postmenopausal women.
Project description:PURPOSE:We initiated a clinical trial to determine the proportion of breast cancer survivors achieving ?5% weight loss using a remotely delivered weight loss intervention (POWER-remote) or a self-directed approach, and to determine the effects of the intervention on biomarkers of cancer risk including metabolism, inflammation, and telomere length. EXPERIMENTAL DESIGN:Women with stage 0-III breast cancer, who completed local therapy and chemotherapy, with a body mass index ?25 kg/m2 were randomized to a 12-month intervention (POWER-remote) versus a self-directed approach. The primary objective was to determine the number of women who achieved at least 5% weight loss at 6 months. We assessed baseline and 6-month change in a panel of adipocytokines (adiponectin, leptin, resistin, HGF, NGF, PAI1, TNF?, MCP1, IL1?, IL6, and IL8), metabolic factors (insulin, glucose, lipids, hs-CRP), and telomere length in peripheral blood mononuclear cells. RESULTS:From 2013 to 2015, 96 women were enrolled, and 87 were evaluable for the primary analysis; 45 to POWER-remote and 42 to self-directed. At 6 months, 51% of women randomized to POWER-remote lost ?5% of their baseline body weight, compared with 12% in the self-directed arm [OR, 7.9; 95% confidence interval (CI), 2.6-23.9; P = 0.0003]; proportion were similar at 12 months (51% vs 17%, respectively, P = 0.003). Weight loss correlated with significant decreases in leptin, and favorable modulation of inflammatory cytokines and lipid profiles. There was no significant change in telomere length at 6 months. CONCLUSIONS:A remotely delivered weight loss intervention resulted in significant weight loss in breast cancer survivors, and favorable effects on several biomarkers.
Project description:Weight cycling, which consists of repeated cycles of intentional weight loss and regain, is common among individuals who try to lose weight. Some evidence suggests that weight cycling may affect biological processes that could contribute to carcinogenesis, but whether it is associated with cancer risk is unclear. Using 62,792 men and 69,520 women enrolled in the Cancer Prevention Study II Nutrition Cohort in 1992, we examined the association between weight cycling and cancer incidence. Weight cycles were defined by using baseline questions that asked the number of times ?10 pounds (4.54 kg) was purposely lost and later regained. Multivariable-adjusted hazard ratios and 95% confidence intervals for all cancer and 15 individual cancers were estimated by using Cox proportional hazards regression. During up to 17 years of follow-up, 15,333 men and 9,984 women developed cancer. Weight cycling was not associated with overall risk of cancer in men (hazard ratio = 0.96, 95% confidence interval: 0.83, 1.11 for ?20 cycles vs. no weight cycles) or women (hazard ratio = 0.96, 95% confidence interval: 0.86, 1.08) in models that adjusted for body mass index and other covariates. Weight cycling was also not associated with any individual cancer investigated. These results suggest that weight cycling, independent of body weight, is unlikely to influence subsequent cancer risk.
Project description:Purpose African American women with breast cancer have higher cancer-specific and overall mortality rates. Obesity is common among African American women and contributes to breast cancer progression and numerous chronic conditions. Weight loss interventions among breast cancer survivors positively affect weight, behavior, biomarkers, and psychosocial outcomes, yet few target African Americans. This article examines the effects of Moving Forward, a weight loss intervention for African American breast cancer survivors (AABCS) on weight, body composition, and behavior. Patients and Methods Early-stage (I-III) AABCS were randomly assigned to a 6-month interventionist-guided (n = 125) or self-guided (n = 121) weight loss program supporting behavioral changes to promote a 5% weight loss. Anthropometric, body composition, and behavioral data were collected at baseline, postintervention (6 months), and follow-up (12 months). Descriptive statistics and mixed models analyses assessed differences between groups over time. Results Mean (± standard deviation) age, and body mass index were 57.5 (± 10.1) years and 36.1 (± 6.2) kg/m2, respectively, and 82% had stage I or II breast cancer. Both groups lost weight. Mean and percentage of weight loss were greater in the guided versus self-guided group (at 6 months: 3.5 kg v 1.3kg; P < .001; 3.6% v 1.4%; P < .001, respectively; at 12 months: 2.7 kg v 1.6 kg; P < .05; 2.6% v 1.6%; P < .05, respectively); 44% in the guided group and 19% in the self-guided group met the 5% goal. Body composition and behavioral changes were also greater in the interventionist-guided group at both time points. Conclusion The study supports the efficacy of a community-based interventionist-guided weight loss program targeting AABCS. Although mean weight loss did not reach the targeted 5%, the mean loss of > 3% at 6 months is associated with improved health outcomes. Affordable, accessible health promotion programs represent a critical resource for AABCS.
Project description:BACKGROUND:Although obesity is an established risk factor for postmenopausal breast cancer, the results of weight loss and breast cancer studies are inconsistent. Therefore, we evaluated associations between weight change and breast cancer risk in postmenopausal women in the Women's Health Initiative Observational Study. METHODS:Postmenopausal women (n = 61,335) who had no prior breast cancer and a normal mammogram had body weight and height measured and body mass index (BMI) calculated at baseline and year 3. Weight change at year 3 was categorized as stable (<5%), loss (?5%), or gain (?5%) with further assessment of weight loss intentionality by self-report. Multivariable Cox proportional hazard regression models were used to evaluate relationships between weight change and subsequent breast cancer incidence. RESULTS:During a mean follow-up of 11.4 years with 3061 incident breast cancers, women with weight loss (n = 8175) had a significantly lower risk of breast cancer compared with women whose weight remained stable (n = 41,139) (hazard ratio [HR], 0.88; 95% confidence interval [CI], 0.78-0.98; P = .02) with no interaction by BMI. Adjustment for mammography did not alter findings (HR, 0.88; 95% CI, 0.78-0.99) with no significant difference by weight loss intentionality. Weight gain (?5%) (n = 12,021) was not associated with breast cancer risk (HR, 1.02; 95% CI, 0.93-1.11) but was associated with higher triple-negative breast cancer incidence (HR, 1.54; 95% CI, 1.16-2.05). CONCLUSIONS:Postmenopausal women who lose weight have lower breast cancer risk than those with stable weight. These findings suggest that postmenopausal women who lose weight may reduce their breast cancer risk.
Project description:PURPOSE:Little research examines whether adiposity or post-diagnosis weight changes influence Cardiovascular disease (CVD) among breast cancer patients for whom effects may differ due to treatment and recovery. METHODS:We studied Stage I-III breast cancer survivors 18 to <80 years, without pre-existing CVD, diagnosed from 1997 to 2013 at Kaiser Permanente. Women reported weight at diagnosis and weight and waist circumference (WC) around 24 months post diagnosis. Using Cox models for time to incident coronary artery disease, heart failure, valve abnormality, arrhythmia, stroke, or CVD death, we examined at-diagnosis body mass index (BMI, n = 3109) and post-diagnosis WC (n = 1898) and weight change (n = 1903, stable, ±5 to <10-lbs or ±?10-lbs). RESULTS:Mean (SD) age was 57 (11) years, and BMI was 28 (6) kg-m2. Post diagnosis, 25% of women gained and 14% lost ?10-lbs; mean (SD) WC was 90 (15) cm. Over a median of 8.28 years, 915 women developed CVD. BMI 25-30-kg/m2 (vs. BMI < 25-kg/m2) was not associated with CVD, while BMI ? 35-kg/m2 increased risk by 33% (HR: 1.33; 95%CI 1.08-1.65), independent of lifestyle and tumor/treatment factors. The increased risk at BMI ? 35-kg/m2 attenuated with adjustment for pre-existing CVD risk factors to HR: 1.20; 95%CI 0.97-1.50. By contrast, even moderate elevations in WC increased risk of CVD, independent of pre-existing risk factors (HR: 1.93; 95%CI 1.31-2.84 comparing ?100-cm vs. ?80-cm). Post-diagnosis weight change had no association with CVD. CONCLUSION:Extreme adiposity and any elevation in WC increased risk of CVD among breast cancer survivors; however, changes in weight in the early post-diagnosis period were not associated with CVD. Survivors with high WC and existing CVD risk factors should be monitored.
Project description:Several studies have found positive associations between birth weight and breast cancer risk at premenopausal ages. The mechanisms underlying this association are not known, but it is possible that it may be mediated through childhood growth. We examined data from a British cohort of 2176 women born in 1946 and for whom there were prospective measurements of birth weight and of body size throughout life. In all, 59 breast cancer cases occurred during follow-up, 21 of whom were known to be premenopausal. Women who weighed at least 4 kg at birth were five times (relative risk (RR)=5.03; 95% confidence interval=1.13, 22.5) more likely to develop premenopausal breast cancer than those who weighed less than 3 kg (P-value for linear trend=0.03). This corresponded to an RR of 2.31 (0.95, 5.64) per 1 kg increase in birth weight. Birth weight was also a predictor of postnatal growth, that is, women who were heavy at birth remained taller and heavier throughout their childhood and young adulthood. However, the effect of birth weight on premenopausal breast cancer risk was only reduced slightly after simultaneous adjustment for height and body mass index (BMI) at age 2 years and height and BMI velocities throughout childhood and adolescence (adjusted RR=1.94 (0.74, 5.14) per 1 kg increase in birth weight). The pathways through which birth weight is associated with premenopausal breast cancer risk seem to be largely independent of those underlying the relation of postnatal growth to risk.
Project description:BACKGROUND:We tested the hypothesis that body mass index (BMI) aged 20 years modifies the association of adult weight gain and breast cancer risk. METHODS:We recruited women (aged 47-73 years) into the PROCAS (Predicting Risk Of Cancer At Screening; Manchester, UK: 2009-2013) Study. In 47,042 women, we determined BMI at baseline and (by recall) at age 20 years, and derived weight changes. We estimated hazard ratios (HRs) and 95% confidence intervals (CIs) for new breast cancer using Cox models and explored relationships between BMI aged 20 years, subsequent weight changes and breast cancer risk. RESULTS:With median follow-up of 5.6 years, 1142 breast cancers (post-menopausal at entry: 829) occurred. Among post-menopausal women at entry, BMI aged 20 years was inversely associated [HR per SD: 0.87 (95% CI: 0.79-0.95)], while absolute weight gain was associated with breast cancer [HR per SD:1.23 (95% CI: 1.14-1.32)]. For post-menopausal women who had a recall BMI aged 20 years <23.4?kg/m2 (75th percentile), absolute weight gain was associated with breast cancer [HR per SD: 1.31 (95% CIs: 1.21-1.42)], but there were no associations for women with a recall BMI aged 20 years of >23.4?kg/m2 (Pinteraction values <0.05). CONCLUSIONS:Adult weight gain increased post-menopausal breast cancer risk only among women who were <23.4?kg/m2 aged 20 years.
Project description:We conducted a phase II feasibility study of a 6-month behavioral weight loss intervention in postmenopausal overweight and obese women at increased risk for breast cancer and the effects of weight loss on anthropomorphic, blood, and benign breast tissue biomarkers. 67 women were screened by random peri-areolar fine-needle aspiration, 27 were registered and 24 participated in the interventional phase. The 24 biomarker evaluable women had a median baseline BMI of 34.2 kg/m(2) and lost a median of 11 % of their initial weight. Significant tissue biomarker modulation after the 6-month intervention was noted for Ki-67 (if restricted to the 15 women with any Ki-67 at baseline, p = 0.041), adiponectin to leptin ratio (p = 0.003); and cyclin B1 (p = 0.001), phosphorylated retinoblastoma (p = 0.005), and ribosomal S6 (p = 0.004) proteins. Favorable modulation for serum markers was observed for sex hormone-binding globulin (p < 0.001), bioavailable estradiol (p < 0.001), bioavailable testosterone (p = 0.033), insulin (p = 0.018), adiponectin (p = 0.001), leptin (p < 0.001), the adiponectin to leptin ratio (p < 0.001), C-reactive protein (p = 0.002), and hepatocyte growth factor (p = 0.011). When subdivided by <10 or >10 % weight loss, change in percent total body and android (visceral) fat, physical activity, and the majority of the serum and tissue biomarkers were significantly modulated only for women with >10 % weight loss from baseline. Some factors such as serum PAI-1 and breast tissue pS2 (estrogen-inducible gene) mRNA were not significantly modulated overall but were when considering only those with >10 % weight loss. In conclusion, a median weight loss of 11 % over 6 months resulted in favorable modulation of a number of anthropomorphic, breast tissue and serum risk and mechanistic markers. Weight loss of 10 % or more should likely be the goal for breast cancer risk reduction studies in obese women.