Life course evolution of body size and breast cancer survival in the E3N cohort

Weight gain during early adulthood, trajectory of body shape and the risk of nonalcoholic fatty liver disease: A prospective cohort study among women

BACKGROUND & AIMS

Obesity is established as a major risk factor for the development of nonalcoholic fatty liver disease (NAFLD). However, the influence of dynamic changes in adiposity over the life course on NAFLD risk remains poorly understood.

METHODS

We collected data from 110,054 women enrolled in the Nurses' Health Study II cohort. Early adulthood weight was ascertained at age 18 years, and weight gain since early adulthood was defined prospectively every 2 years. We used a group-based modeling approach to identify five trajectories of body shape from age 5 years up to age 50 years. NAFLD was defined by physician-confirmed diagnoses of fatty liver, after excluding excess alcohol intake and viral hepatitis, using validated approaches.

RESULTS

We documented 3798 NAFLD cases over a total of 20 years of follow-up. Compared to women who maintained stable weight (±2 kg), women with ≥20 kg of adulthood weight gain had the multivariable aHR of 6.96 (95% CI, 5.27-9.18), and this remained significant after further adjusting for early adulthood BMI and updated BMI (both P trend <0.0001). Compared to women with a medium-stable body shape trajectory, the multivariable aHRs for NAFLD were, 2.84 (95% CI, 2.50-3.22) for lean-marked increase, 2.60 (95% CI, 2.27-2.98) for medium-moderate increase, and 3.39 (95% CI, 2.95-3.89) for medium-marked increase.

CONCLUSIONS

Both early adulthood weight gain and lifetime body shape trajectory were significantly and independently associated with excess risk of developing NAFLD in mid-life. Maintaining both lean and stable weight throughout life may offer the greatest benefit for the prevention of NAFLD.

Anthropometry, body shape in early-life and risk of premenopausal breast cancer among Latin American women: results from the PRECAMA study

Cumulating evidence in Caucasian women suggests a positive association between height and premenopausal breast cancer risk and a negative association with overall adiposity; however data from Latin America are scarce. We investigated the associations between excess adiposity, body shape evolution across life, and risk of premenopausal breast cancer among 406 cases (women aged 20-45) and 406 matched population-based controls from Chile, Colombia, Costa Rica, and Mexico. Negative associations between adult adiposity and breast cancer risk were observed in adjusted models (body mass index (BMI): Odds ratio (OR) per 1 kg/m2 = 0.93; 95% confidence interval = 0.89-0.96; waist circumference (WC): OR per 10 cm = 0.81 (0.69-0.96); hip circumference (HC): OR per 10 cm = 0.80 (0.67-0.95)). Height and leg length were not associated with risk. In normal weight women (18.5 ≤ BMI < 25), women with central obesity (WC > 88 cm) had an increased risk compared to women with normal WC (OR = 3.60(1.47-8.79)). Residuals of WC over BMI showed positive associations when adjusted for BMI (OR per 10 cm = 1.38 (0.98-1.94)). Body shape at younger ages and body shape evolution were not associated with risk. No heterogeneity was observed by receptor status. In this population of Latin American premenopausal women, different fat distributions in adulthood were differentially associated with risk of breast cancer.

Adult Overweight and Survival from Breast and Colorectal Cancer in Swedish Women

BACKGROUND

The impact of overweight duration and intensity during adulthood on the prognosis after a cancer diagnosis remains largely unknown. We investigated this association in Swedish women with breast and colorectal cancer.

METHODS

A cohort of 47,051 women from the Swedish Lifestyle and Health Study was included, of whom 1,241 developed postmenopausal breast (mean age at diagnosis, 57.5 years) and 259 colorectal (mean age at diagnosis, 59.1 years) cancer. Trajectories of body mass index (BMI) between ages 20 and 50 years were estimated for the full cohort using a quadratic growth model and studied in relation to risk of death from any cause using multivariate Cox regression models among cancer survivors.

RESULTS

Compared with patients with cancer who were never overweight (BMI < 25) during early adulthood (ages 20-50 years), the risk of early death from breast cancer increased by 3% [hazard ratio (HR) = 1.03; 95% confidence interval (CI), 1.01-1.05] and from colorectal cancer by 4% (HR = 1.04; 95% CI, 1.01-1.06) for every year lived with overweight. A higher intensity of overweight (i.e., a combination of duration and degree of overweight-a concept comparable to pack-years of cigarette smoking) further increased the risk of dying in this population. Although risks were slightly more pronounced for women diagnosed with late-stage breast cancer, no clear association was found for colorectal cancer.

CONCLUSIONS

Our results suggest that adulthood overweight duration and intensity have a long-lasting influence on breast and colorectal cancer survival.

IMPACT

Our study highlights the need for effective prevention of overweight and obesity starting at an early age.

Body Weight and Breast Cancer: Nested Case-Control Study in Southern Brazil

BACKGROUND

Current studies have shown that fast weight gain may be more important than body mass index on the incidence of breast cancer. The aim of this study was to evaluate the association between body weight and breast cancer.

PATIENTS AND METHODS

This was a case-control study nested in a cohort of a breast cancer mammography screening program in Southern Brazil. A trained investigator administered a standardized interview to collect sociodemographic and clinical data, and body weight history (weight at menarche, at marriage, at first and last pregnancy, and at menopause). Current anthropometric measurements were also made.

RESULTS

Fifty-seven women with cancer (66.7% postmenopausal) and 159 controls were included. Current age (60.3 ± 10.4 vs. 55.8 ± 8.4 years, P < .01), marital status (49.1% vs. 64.8% with a partner, P = .03), and physical activity (48.2% vs. 32.3% sedentary, P = .01) were significantly different between cases and controls, respectively. Odds ratio showed that age and current waist circumference were associated with postmenopausal cancer. No difference was found in relation to body weight at different stages of life.

CONCLUSION

Women with social vulnerability recruited at a mammography screening program in Southern Brazil showed a large weight gain during life, but no significant differences were found in body weight between women with or without breast cancer.

Pre-diagnostic changes in body mass index and mortality among breast cancer patients

PURPOSE

We investigated whether changes in body mass index (BMI) before a breast cancer diagnosis affected mortality and whether trajectories more accurately predict overall mortality compared to a single measure of BMI.

METHODS

Our prospective cohort comprised 2012 women with breast cancer who reported their weight in each decade from 20 to 50-64 years of age. We used trajectory analysis to identify groups with similar development patterns in BMI and Cox proportional hazards models to examine the association between trajectory groups and mortality, and interactions with oestrogen receptor status and smoking. We used c-index statistics to compare the trajectory model with the single measure model of BMI.

RESULTS

We identified three distinct trajectory groups, with a mean BMI at age 20 of 19, 22 and 24 increasing to 23 (normal-to-normal), 29 (normal-to-overweight) and 37 (normal-to-obese) at 50-64 years of age, respectively. Women in the normal-to-obese trajectory group experienced significantly higher overall mortality than those in the normal-to-normal trajectory group (HR 1.76, 95% CI 1.21‒2.56). The association declined to a non-significant level after adjustments for clinical prognostic factors. Although not significant, the same tendency was seen for breast cancer-specific mortality. The association was strongest in women with oestrogen receptor-negative tumours. Weight changes over time were not significantly different from a single BMI measure before diagnosis to predict survival.

CONCLUSION

Weight gain affects overall mortality after breast cancer but clinical prognostic factors largely eliminate the association. Using trajectories of weight changes did not improve the predictive value compared to a single measure of BMI.