Adult weight change and the risk of pre- and postmenopausal breast cancer in the Chinese Wuxi Exposure and Breast Cancer Study

How does weight gain since the age of 18 years affect breast cancer risk in later life? A meta-analysis

Early life factors are important risk factors for breast cancer. The association between weight gain after age 18 and breast cancer risk is inconsistent across previous epidemiologic studies. To evaluate this association, we conducted a meta-analysis according to PRISMA guidelines and the established inclusion criteria. We performed a comprehensive literature search using Medline (Ovid), Embase, Scopus, Cochrane Library, and ClinicalTrials.gov to identify relevant studies published before June 3, 2022. Two reviewers independently reviewed the articles for final inclusion. Seventeen out of 4,725 unique studies met the selection criteria. The quality of studies was assessed using the Newcastle-Ottawa Scale (NOS), and all were of moderate to high quality with NOS scores ranging from 5 to 8. We included 17 studies (11 case-control, 6 cohort) in final analysis. In case-control studies, weight gain after age 18 was associated with an increased risk of breast cancer (odds ratio [OR] = 1.25; 95% CI = 1.07-1.48), when comparing the highest versus the lowest categories of weight gain. Menopausal status was a source of heterogeneity, with weight gain after age 18 associated with an increased risk of breast cancer in postmenopausal women (OR = 1.53; 95% CI = 1.40-1.68), but not in premenopausal women (OR = 1.01; 95% CI = 0.92-1.12). Additionally, a 5 kg increase in weight was positively associated with postmenopausal breast cancer risk (OR = 1.12; 95%CI = 1.05-1.21) in case-control studies. Findings from cohort studies were identical, with a positive association between weight gain after age 18 and breast cancer incidence in postmenopausal women (relative risk [RR] = 1.30; 95% CI = 1.09-1.36), but not in premenopausal women (RR = 1.06; 95% CI = 0.92-1.22). Weight gain after age 18 is a risk factor for postmenopausal breast cancer, highlighting the importance of weight control from early adulthood to reduce the incidence of postmenopausal breast cancer.

Obesity and Breast Cancer Risk: The Oncogenic Implications of Metabolic Dysregulation

CONTEXT

Breast cancer is increasing in prevalence in parallel with rising rates of obesity worldwide. Obesity is recognized as a leading modifiable risk factor for the development of breast cancer; however, this association varies considerably by clinicopathologic features, and the underlying mechanisms are complex.

EVIDENCE ACQUISITION

Pubmed literature search using combinations of "obesity," "breast cancer risk," "diet," "exercise," "weight gain," "weight loss," "adipose tissue inflammation," "crown-like structure," "immune markers," "metformin," "gliflozins," "SGLT-2i," "GLP1-RA," and related terms.

EVIDENCE SYNTHESIS

Elevated body mass index and weight gain are associated with increased risk of postmenopausal, hormone receptor-positive breast cancer. Emerging evidence suggests that adverse measures of body composition in individuals of any weight can also confer increased breast cancer risk. Mechanistically, various factors including altered adipokine balance, dysfunctional adipose tissue, dysregulated insulin signaling, and chronic inflammation contribute to tumorigenesis. Weight loss and more specifically fat mass loss through lifestyle and pharmacologic interventions improve serum metabolic and inflammatory markers, sex hormone levels, and measures of breast density, suggesting a link to decreased breast cancer risk.

CONCLUSION

Incorporating markers of metabolic health and body composition measures with body mass index can capture breast cancer risk more comprehensively. Further studies of interventions targeting body fat levels are needed to curb the growing prevalence of obesity-related cancer.

Role of adipocyte browning in prostate and breast tumor microenvironment

Prostate cancer (PC) and breast cancer (BC) are the most common cancers in men and women, respectively, in developed countries. The increased incidence of PC and BC largely reflects an increase in the prevalence of obesity and metabolic syndrome. In pathological conditions involving the development and progression of PC and BC, adipose tissue plays an important role via paracrine and endocrine signaling. The increase in the amount of local adipose tissue, specifically periprostatic adipose tissue, may be a key contributor to the PC pathobiology. Similarly, breast adipose tissue secretion affects various aspects of BC by influencing tumor progression, angiogenesis, metastasis, and microenvironment. In this context, the role of white adipose tissue (WAT) has been extensively studied. However, the influence of browning of the WAT on the development and progression of PC and BC is unclear and has received less attention. In this review, we highlight that adipose tissue plays a vital role in the regulation of the tumor microenvironment in PC or BC and highlight the probable underlying mechanisms linking adipose tissue with PC or BC. We further discuss whether the browning of WAT could be a therapeutic strategy for the treatment of PC and BC.

Changes in weight and waist circumference during menopausal transition and postmenopausal breast cancer risk

Our study aimed to investigate the association between changes in weight and waist circumference (WC) during menopausal transition and breast cancer risk in Asian women. In total, 184 931 women aged 40 to 59 years with a premenopausal status at the first screening in 2009 to 2010 and a postmenopausal status at the second screening in 2011 to 2012 were included in the analysis. Changes in weight and WC during menopausal transition were classified as loss (>2.5 kg; >2.5 cm), stable (±2.5 kg; ±2.5 cm), and gain (2.5-4.9 kg, ≥5 kg; 2.5-4.9 cm, ≥5 cm). WC gain of 5 cm or more during menopausal transition was associated with an increased risk of breast cancer with an HR of 1.15 (95% CI = 1.01-1.30), compared to stable WC (±2.5 cm). Among obese premenopausal women, increased WC ≥5 cm during menopausal transition was associated with increased breast cancer risk with an HR of 1.22 (95% CI = 1.03-1.44). Similarly, in women with premenopausal WC ≥80 cm, increased WC of ≥5 cm during menopausal transition was likely to increase the breast cancer risk (HR = 1.36, 95% CI = 1.13-1.88) than in women with stable WC. However, in premenopausal women with BMI <23 kg/m2 or WC <80 cm, changes in WC during menopausal transition did not show an association. Weight gain during menopausal transition was not associated with the risk of breast cancer. Changes in central obesity during menopausal transition in combination with premenopausal obesity status are associated with breast cancer risk after menopause.

Risk factors for breast cancer and their association with molecular subtypes in a population of Northeast Brazil

BACKGROUND

The risk factors for breast cancer (BC) among women in Brazilian populations are poorly understood. To date, few Brazilian studies have addressed the potential association between risk factors and molecular BC subtypes. This case-control study aimed to identify risk factors for BC in a population of Northeast Brazil.

METHODS

Data from 313 patients with invasive BC and 321 healthy controls were obtained from medical records from two cancer treatment centres and personal interviews. Of the 313 BC patients, 224 (71.6%) had reached menopause. The following distribution of subtypes was found among 301 patients: (1) Luminal A: 54 (17.9%); (2) Luminal B: 175 (58.1%); (3) HER2/neu: 29 (9.7%); and (4) triple-negative breast cancer (TNBC): 43 (14.3%). Odds ratios (ORs) and confidence intervals (CIs) were determined using regression analysis.

RESULTS

Regression modelling indicated that family history, obesity (≥ 30.0 kg/m²), alcohol consumption and contraceptive use increased the overall risk of BC 1.78 (95% CI: 1.22-2.59), 1.69 (95% CI: 1.08-2.63), 2.21 (95% CI: 1.44-3.39) and 2.99 (95% CI: 2.09-4.28) times, respectively. After stratification for menopausal status, alcohol consumption increased the risk of BC 4.15 (95% CI: 2.13-8.11) times, and obesity, as a single variable, increased the risk of BC 2.02 (95% CI: 1.22-3.37) times, only among postmenopausal women. In a case-control analysis, the risk of TNBC and Luminal B breast cancer were 4.06 (95% CI: 1.58-10.42) and 1.87 times (95% CI: 1.13-3.11) higher, respectively, in obese women than in non-obese women. Furthermore, alcohol consumption increased the risk of Luminal A and B subtypes 7.08 (3.40-14.73) and 1.77 (1.07-2.92) times, respectively.

CONCLUSION

Family history, contraceptive use, obesity and alcohol consumption increased the risk of BC. Obesity and alcohol consumption differentially increased risk of TNBC and Luminal molecular subtypes.

Effect of long-term weight gain on the risk of breast cancer across women's whole adulthood as well as hormone-changed menopause stages: A systematic review and dose-response meta-analysis

Adult weight gain is a good indicator of excess body fatness for breast cancer risk. However, little is known about the effect of weight gain during other special periods in women's lifetime. A publication search in PubMed and Embase through April 2020 was conducted. A primary meta-analysis comparing the highest and lowest category and a secondary meta-analysis based on dose-response meta-analysis were performed to calculate risk estimates with 95% confidence intervals using a random-effects model. For postmenopausal breast cancer, the relative risk for highest vs. lowest category of adult weight gain and weight gain since menopause were 1.55 and 1.59 (RR = 1.55, 95% CI: 1.40, 1.71; RR = 1.59, 95% CI: 1.23, 2.05). For per 5 kg increase in adult weight gain, the summary RR of postmenopausal breast cancer was 1.08 (RR = 1.08, 95% CI: 1.07, 1.09), which is much stronger in Asian women (RR = 1.34, 95% CI: 1.22, 1.47). There was no significant finding among premenopausal women (RR = 1.00, 95% CI: 0.83, 1.21). Same as adult weight gain, weight gain since menopause might be an equivalent predictor for postmenopausal breast cancer risk. More studies are warranted to confirm the magnitude of this association further.

Current Landscape: The Mechanism and Therapeutic Impact of Obesity for Breast Cancer

Obesity is defined as a chronic disease induced by an imbalance of energy homeostasis. Obesity is a widespread health problem with increasing prevalence worldwide. Breast cancer (BC) has already been the most common cancer and one of the leading causes of cancer death in women worldwide. Nowadays, the impact of the rising prevalence of obesity has been recognized as a nonnegligible issue for BC development, outcome, and management. Adipokines, insulin and insulin-like growth factor, sex hormone and the chronic inflammation state play critical roles in the vicious crosstalk between obesity and BC. Furthermore, obesity can affect the efficacy and side effects of multiple therapies such as surgery, radiotherapy, chemotherapy, endocrine therapy, immunotherapy and weight management of BC. In this review, we focus on the current landscape of the mechanisms of obesity in fueling BC and the impact of obesity on diverse therapeutic interventions. An in-depth exploration of the underlying mechanisms linking obesity and BC will improve the efficiency of the existing treatments and even provide novel treatment strategies for BC treatment.

Racial/ethnic disparities in weight or BMI change in adulthood and pancreatic cancer incidence: The multiethnic cohort

INTRODUCTION

Compared to non-Hispanic Whites, Japanese Americans, Native Hawaiians, and African Americans have higher incidences of pancreatic cancer (PCa) that are not entirely explained by rates of obesity but may be explained by weight changes throughout adulthood.

METHODS

The multiethnic cohort is a population-based prospective cohort study that has followed 155,308 participants since its establishment between 1993 and 1996. A total of 1,328 incident cases with invasive PCa were identified through 2015. We conducted separate multivariable Cox proportional hazards models for self-reported weight-change and BMI-change (age 21 to cohort entry) to determine the association with PCa risk, adjusting for potential confounders including weight or BMI at age 21.

RESULTS

The mean age at cohort entry was 59.3 years (SD 8.9). An increased risk of PCa was associated with: 1) weight (HR per10 lbs = 1.06; 95% CI = 1.03-1.09) or BMI (HR per kg/m2  = 1.04; 95% CI = 1.02-1.05) at age 21; and 2) weight (HR per 10 lbs = 1.03; 95% CI = 1.01-1.05) or BMI (HR = 1.02; 95% CI = 1.00-1.03) at cohort entry. We found increased risk of PCa between weight (HR per 10 lbs = 1.03; 95% CI = 1.01-1.05) and BMI (HR per 5 kg/m2  = 1.08; 95% CI = 1.01-1.15) change from age 21 to baseline. There were significant interactions between race/ethnicity and weight (p = 0.008) or BMI (p = 0.03) at baseline, and weight (p = 0.02) or BMI (p = 0.02) change. Weight and BMI change through adulthood significantly increased the risk of PCa for Japanese Americans and Latinos, but not for African American, White, or Hawaiian participants.

CONCLUSION

Our findings indicate that weight or BMI gain has a significant and independent impact on PCa risk, specifically among Latinos and Japanese Americans.

Evaluation of the body mass index in breast cancer prognosis in a cohort of small-stature overweight patients: multi-center study in China

Background

Overweight and obesity have become a major health issue in the past 30 years. Several studies have already shown that obesity is significantly associated with a higher risk of developing breast cancer. However, few studies have assessed the prognostic value of the body mass index (BMI) in Asian populations. The purpose of this study was to retrospectively analyze the impact of BMI on the prognosis of breast cancer in overweight, under 160 cm tall patients from southern China.

Methods

We retrospectively analyzed data from 525 breast cancer patients diagnosed between 2003 to 2010 in a multi-center of China. After applying the exclusion criteria, 315 patients with complete data were retained. Their clinical and pathological characteristics were compared using the chi-square test. Survival analysis was performed with the Kaplan-Meier method. Univariate and multivariate analyses were performed using Cox regression to calculate hormone receptor status, HER-2 status, lymph node status, age, BMI and tumor size hazard ratio (HR), and 95% confidence intervals (95% CI).

Results

There was a strong correlation between BMI and age in the baseline feature analysis (P=0.001). After grouping the patients according to the molecular type of cancer, we found that in Luminal A and B, the BMI was related to age (P=0.002, P=0.010). The disease-free survival (DFS) and overall survival (OS) of patients with different BMI were not significantly different. This conclusion was also reached by pairwise comparison of subgroups. There was no significant difference in recurrence in patients from different BMI groups. We did not find a critical weight threshold associated with higher risk of recurrence. There were no statistically significant differences in treatment among the three BMI groups of overweight patients.

Conclusions

We found that the BMI of Chinese breast cancer patients is related to age but not prognosis.

Body size, silhouette trajectory and the risk of breast cancer in a Moroccan case-control study

BACKGROUND

There is convincing evidence demonstrating that body size characteristics such as adiposity and height are associated with breast cancer in westernized countries. However, little is known about this relationship in North African countries currently undergoing nutritional transition and industrialization. The aim of this study was to explore associations between various body size characteristics, silhouette trajectories and the risk of breast cancer among Moroccan women.

METHODS

In this case-control study conducted in the Fez region (2016-2017), detailed measures of body size were collected for 300 cases of breast cancer and 300 matched controls. Unconditional logistic regression was used to assess the association between body size and breast cancer risk adjusting for confounding factors.

RESULTS

Higher waist circumference and hip circumference were positively associated with breast cancer risk in pre- (highest [T3] vs. lowest tertile [T1]: OR = 2.92, 95% confidence intervals [CI]: 1.33-6.42; OR = 3.00, 95% CI: 1.42-6.33, respectively) and post-menopausal women (T3 vs. T1: OR = 4.46, 95% CI: 1.86-10.66; OR = 4.08, 95% CI: 1.76-9.42, respectively). Body shape at younger ages (6-11 years) was inversely associated with the risk of breast cancer in premenopausal women (large vs. lean silhouette: OR = 0.31, 95% CI: 0.12-0.80). Women with the greatest increase in body shape trajectory had higher risk for both pre- and post-menopausal breast cancer (T3 vs. T1: OR = 2.74, 95% CI: 1.03-7.26; OR = 3.56, 95% CI: 1.34-9.44, respectively).

CONCLUSION

Our findings suggest that adiposity, body shape at younger ages, and silhouette trajectory may play a role in the development of pre- and post-menopausal breast cancer among Moroccan women. Larger-scale prospective studies are needed to confirm our findings and to explore these associations with breast cancer subtypes.

Long-term excess body fat in adulthood and the risk of pre- and postmenopausal breast cancer in Chinese women

PURPOSE

This study aimed to investigate the association between long-term excess body fat and breast cancer risk by studying adult weight gain together with the subsequent weight fluctuations.

METHODS

Weight gain measure in three different time periods in adulthood of 1500 participants was collected in a case-control study of Western China. Logistic regression models were used to estimate odds ratios and 95% CIs.

RESULTS

The increased risk of postmenopausal BC was associated with adult weight gain at 5 years and at 10 years before enrollment (OR 1.24, 95% CI 1.03-1.49 per 5 kg increase; OR 1.40, 95% CI 1.14-1.70 per 5 kg increase) but was not associated with adult weight gain at enrollment (OR 0.97, 95% CI 0.81-1.16 per 5 kg increase). Only a positive association was observed in premenopausal women who had gained > 5.0 kg at 10 years before enrollment (OR 1.61, 95% CI 1.10-2.35). Women who had gained > 5.0 kg at 10 years before enrollment and continued to gain during the subsequent 5 years had the highest postmenopausal BC risk (OR 3.34, 95% CI 1.58-7.08).

CONCLUSION

Adult weight gain at 5 years and 10 years before enrollment are more closely associated with postmenopausal BC risk than adult weight gain at enrollment in Western China. Controlling body weight as early as possible throughout adulthood to keep weight gain not more than 5.0 kg is particularly necessary for Chinese women.