Obesity and breast cancer risk for pre- and postmenopausal women among over 6 million Korean women

Changes in health behaviors and risk of depression after breast cancer diagnosis and treatment: a nationwide cohort study

PURPOSE

Protective lifestyle behaviors could potentially mitigate the risk of depression in breast cancer survivors. This study examined the association between changes in key health behaviors and depression risk after breast cancer diagnosis and treatment.

METHODS

This nationwide cohort study assessed 30,523 breast cancer survivors without a prior history of depression, focusing on changes in weight, smoking habits, alcohol consumption, and physical activity from pre- to post-cancer diagnosis. The primary outcome was incident depression, with adjusted hazard ratios and confidence intervals calculated to consider potential confounders.

RESULTS

During an average follow-up of 5.3 years (160,755 person-years), lifestyle changes post-diagnosis included decreases in smoking (2.8% to 0.9%) and alcohol consumption (24.9% to 7.5%) and an increase in physical activity (18.9% to 32.1%). Substantial weight gain (> 10%) was associated with a 27% elevated risk of depression compared to those who maintained weight. Both continuation and cessation of smoking were associated with increased depression risk compared to sustained non-smokers. Changes in alcohol consumption, either initiation or cessation, were associated with increased depression risk compared to sustained non-drinkers. Conversely, breast cancer survivors who became inactive post-diagnosis had a reduced risk of depression compared to those who remained inactive. Our exploratory analysis showed that regular physical activity prior to diagnosis was associated with a 7% lower risk of depression compared to inactivity.

CONCLUSION

We observed that post-diagnosis weight gain exceeding 10%, sustaining or quitting smoking, starting or stopping alcohol consumption, and pre-diagnosis physical inactivity were all associated with an increased risk of depression in breast cancer survivors. Healthcare providers should support healthy behaviors to mitigate depression risk after breast cancer diagnosis and treatment.

Weight change and cardiovascular disease incidence in breast cancer survivors: a nationwide cohort study

BACKGROUND

Breast cancer survivors (BCS) face a higher risk of cardiovascular disease (CVD) due to treatment-related cardiotoxicity and pre-existing conditions. We investigated how post-diagnosis weight changes and obesity impact CVD risk in this population.

METHOD

Using the Korean National Health Insurance Service database (2010-2019), BCS without previous history of CVD were enrolled. Weight change was determined using standardized anthropometric protocols during biennial health examinations pre- and post-diagnosis. The primary outcome was incident CVD, a composite of myocardial infarction (MI) and ischemic stroke. Adjusted hazard ratios (aHRs) and confidence intervals (CIs) were estimated, accounting for cardiovascular risk factors, cancer treatments, and sociodemographic variables.

RESULTS

During a mean follow-up of 3.70 years among the 42,547 BCS (mean [SD] age 53.4 [9.4] years), substantial weight gain (> 10%) was associated with increased CVD risk (aHR 1.66, 95% CI 1.05-2.62) and MI risk (aHR 1.83, 95% CI 1.01-3.33) compared to those who maintained their weight. The association between change in obesity status and CVD risk was not significant. Among BCS with sustained obesity, CVD risk was more pronounced in younger survivors (< 50 years) (aHR 3.58, 95% CI 1.94-6.61), and in those using tamoxifen (aHR 1.74, 95% CI 1.11-2.75) (P-interactions < 0.05).

CONCLUSIONS

Our findings suggest that BCS who experience substantial weight gain post-diagnosis have an increased risk of CVD. Further intervention studies (e.g., GLP-1 agonist) are needed to ascertain the effects of weight changes on CVD risks in BCS.

The mediating roles of anthropo-metabolic biomarkers on the association between beverage consumption and breast cancer risk

BACKGROUND

Breast cancer (BC) is the most common malignancy in women, yet the role of beverage consumption in BC risk remains unclear. Additionally, the contribution of anthropo-metabolic biomarkers as mediators is unknown, limiting the development of effective prevention strategies.

METHODS

This study included 13,567 participants from the Guangzhou Biobank Cohort Study (GBCS), where beverage consumption was assessed at baseline using a food frequency questionnaire. BC cases were identified through cancer registry linkage over a mean follow-up of 14.8 years. Mendelian randomization (MR) analyses were performed to evaluate the causal effects of beverage consumption on BC risk, with a two-step MR approach used to estimate mediation effects.

RESULTS

During follow-up, 243 BC cases were identified. Weekly consumption of ≥ 1 portion of sugar sweetened beverages (SSB), versus < 1 portion, was significantly associated with a higher risk of BC (hazard ratio [HR] 1.58, 95% confidence interval [CI] 1.12-2.23). This association was partly mediated by body mass index (proportion mediated [PM] 4.2%, 95% CI 0.9-17.1%) and uric acid (PM 18.8%, 95% CI 1.5-77.5%). Weekly consumption of > 6 portions of dairy-based milk was associated with a non-significantly higher BC risk (HR 1.41, 95% CI 0.99-2.03), while 3-6 portions of soy milk were associated with a lower BC risk (HR 0.31, 95% CI 0.10-0.98). No significant associations were found for pure fruit juice, coffee, tea, or alcoholic drinks. MR analyses supported the detrimental effect of SSB on BC risk, with high-density lipoprotein cholesterol, polyunsaturated fatty acids to total fatty acids (TFAs) ratio, and omega-6 fatty acids to TFAs ratio mediating 2.44%, 2.73%, and 3.53% of the association, respectively.

CONCLUSION

This study suggested that SSB consumption was a risk factor for BC and identified key anthropo-metabolic biomarkers mediating this relationship. Reducing SSB consumption and addressing associated metabolic pathways may offer effective strategies for BC prevention.

Obesity and Risk of Pre- and Postmenopausal Breast Cancer in Africa: A Systematic Review

Background and Aims: Several epidemiological studies have investigated the relationship between anthropometric factors and breast cancer (BC), but the results, particularly for premenopausal BC, remain inconsistent and contradictory. The aim of this systematic review is to present an overview of studies examining the association between obesity and BC risk in African women, by menopausal status. Methods: PubMed, Scopus, Web of Science, and Google Scholar were searched until 17 February 2025 to identify published articles. The review included original studies, with no restrictions on publication date or language. The exposures studied were height, weight, body mass index (BMI), waist circumference (WC), hip circumference (HC), and waist-to-hip ratio (WHR). The quality of the studies was assessed using the National Institute of Health (NIH). Study selection and data extraction were carried out by two authors separately. Results: A total of fifteen case-control studies were included in this systematic review, comprising 45,056 subjects (7221 cases and 37,835 controls). Among them, fourteen studies reported stratified results for pre- and postmenopausal women, and one reported findings for only premenopausal BC. We found that BMI was associated with an increased risk of BC in both premenopausal and postmenopausal women, though the associations varied across studies. Height was associated with an increased risk of pre- and postmenopausal BC. WHR was positively associated with BC in pre- and postmenopausal women, while WC showed a positive association with the risk of postmenopausal BC, and inconsistent results with premenopausal BC. Finally, a higher HC was positively associated with premenopausal and postmenopausal BC. Conclusions: The risk of developing BC is higher in obese postmenopausal women. The protective role of BMI has not been demonstrated in African premenopausal women. WHR is a risk factor for premenopausal and postmenopausal BC. There is a need to study the influence of stages of overweight and obesity on BC risk in a large sample of African women in-depth.

Can exercise as a complementary technique manage inflammatory markers in women with breast cancer who are overweight and obese? A systematic review and meta-analysis

BACKGROUND

Inflammation can result in the development of breast cancer in women with overweight and obese, and also affects the outcome and prognosis of breast cancer patients, thereby decreasing the cure and survival rates of breast cancer patients. Exercise may benefit breast cancer patients as a supplement to conventional treatments. However, research on the effects of exercise on inflammatory markers in women with breast cancer who are overweight and obese remains incomplete.

OBJECTIVE

A systematic review and meta-analysis were used to study the effects of exercise on inflammatory markers in women with breast cancer who are overweight and obese.

METHOD

Literature up to May 2024 was searched from databases such as Cochrane, Embase, Pubmed, Web of Science, and EBSCO, and English-language randomized controlled trials (RCTs) that met the inclusion criteria were screened. The screening criteria were as follows (A) written in English; (B) RCT; (C) studied in women with overweight obese and breast cancer; (D) outcome measures: inflammatory markers; (E) the duration of the exercise intervention was unlimited.

RESULTS

A total of 14 articles and 1064 participants were included. Exercise significantly reduced C-reactive protein (CRP) (MD: -0.52, 95 % CI: -0.94 to -0.11; p = 0.01; heterogeneity p < 0.1), interleukin-6 (IL-6) (MD: -0.87, 95 % CI: -1.62 to -0.11; p = 0.02; heterogeneity p < 0.1), and leptin (MD: -0.92, 95 % CI: -1.71 to -0.13; p = 0.02; heterogeneity p < 0.1) levels and exercise significantly increased adiponectin levels (MD: 0.89, 95 % CI: 0.03-1.75, p = 0.04; heterogeneity p < 0.1) but had no effect on tumor necrosis factor-α (TNF-α) (MD: -0.26, 95 % CI: -0.82-0.29; p = 0.35; heterogeneity p < 0.1) and IL-10 (MD: 0.14, 95 % CI: -0.17-0.45; p = 0.37; heterogeneity p = 0.45) were not significant. In addition, subgroup analyses suggest that combination training (CE) may be the most recommended type of exercise to decrease pro-inflammatory markers, and increase anti-inflammatory markers in women with overweight obesity, and have breast cancer.

CONCLUSION

Exercise significantly reduced CRP, IL-6, and leptin levels and overall increased adiponectin levels in women with overweight obese, and breast cancer. However, the effects on TNF-α and IL-10 levels were not significant. CE may be the most recommended type of exercise for reducing pro-inflammatory factors and increasing anti-inflammatory factors. Therefore, this study considers exercise as an effective complementary approach to managing inflammatory markers in women with breast cancer who are overweight and obese. Future researchers may consider exploring the combined effects of exercise and dietary control, weight loss, and other factors, and formulate a comprehensive treatment plan accordingly.

General obesity, abdominal obesity, and the risk of cardiovascular disease including stroke in 5-year breast cancer survivors

BACKGROUND

To assess the association between discrepancies between general obesity and abdominal obesity and the risk of subsequent cardiovascular disease (CVD), including stroke, in breast cancer survivors.

METHODS

We undertook a retrospective cohort study using data from the National Health Insurance Service of South Korea. Among 72,174 5-year breast cancer survivors aged 40 years and above, body mass index (BMI) and waist circumference (WC) were used to determine obesity status. Cox proportional hazards models were used to evaluate the association of obesity and risk of CVD, including stroke.

RESULTS

Compared to those with normal WC and BMI, those who were overweight without abdominal obesity, had abdominal obesity only, and overweight with abdominal obesity, had higher risks of CVD [aHR(95 % CI) 1.23(1.02-1.48), 1.51(1.16-1.95), and 1.55(1.31-1.75), respectively] and total stroke [1.09(0.86-1.38), 1.63(1.20-2.23), and 1.40(1.17-1.68), respectively]. Compared to those overweight, those with abdominal obesity only had a significantly higher risk of ischemic stroke [2.04(1.14-3.65)].

CONCLUSIONS

Breast cancer survivors with higher BMI and/or abdominal obesity were associated with an elevated risk of CVD, including stroke.

Trends in the Disease Burden and Risk Factors of Women's Cancers in China From 1990 to 2019

Objectives

To examine age-specific trends and risk factors in the burden of women's cancers (WCs) in China from 1990 to 2019 to inform strategies.

Methods

Data were sourced from the Global Burden of Disease 2019 and World Population Prospects 2019. Time trends, age differences, and key factors for breast, cervical, and ovarian cancers (BC, CC, and OC) were analyzed based on age-standardized incidence rate (ASIR) and disability-adjusted life years (DALYs) rate.

Results

ASIRs for BC and CC increased over the study period, with a slower growth rate for CC after 2005, likely due to targeted HPV prevention. OC showed the highest ASIR and DALY increases, indicating a growing concern. Peak ASIR for BC and CC was in women aged 50-55, while OC showed a higher burden in women aged 70-79. Lower DALYs in women born after 1985 suggest improved healthcare access.

Conclusion

This study highlights significant trends in cancer burden among Chinese women, driven by age and reproductive health policies. Future efforts should enhance screening, health literacy, and age-targeted risk reduction for specific cancer types.

Changes in Physical Activity and Cardiovascular Disease Risk in Cancer Survivors: A Nationwide Cohort Study

Background

Cancer survivors face an elevated risk of cardiovascular disease, with physical inactivity after cancer treatment potentially worsening this risk.

Objectives

The aim of this study was to investigate the association between physical activity before and after a cancer diagnosis and the risk for heart disease.

Methods

A nationwide cohort of 269,943 cancer survivors (mean age 56.3, 45.7% men) was evaluated for physical activity adherence 2 years before and after diagnosis. The primary outcomes were the incidence of myocardial infarction (MI), heart failure (HF), and atrial fibrillation. Subdistribution HRs (sHRs) and 95% CIs were calculated using Gray's method, accounting for death as a competing risk.

Results

Over a follow-up period of 1,111,329.28 person-years, compared with those who remained inactive, persistent physical activity was associated with a 20% reduction in MI risk (sHR: 0.80; 95% CI: 0.70-0.91) and a 16% reduction risk in HF risk (sHR: 0.84; 95% CI: 0.78-0.90). Initiating physical activity after a cancer diagnosis was linked to an 11% lower risk for MI (sHR: 0.89; 95% CI: 0.79-0.99) and a 13% lower risk for HF (sHR: 0.87; 95% CI: 0.82-0.93). Being active only before diagnosis was associated with a 20% lower risk for MI (sHR: 0.80; 95% CI: 0.71-0.91) and a 6% lower risk for HF (sHR: 0.94; 95% CI: 0.88-1.00). No association was observed between physical activity and atrial fibrillation risk. Associations varied by primary cancer site.

Conclusions

These findings underscore the importance of maintaining physical activity for cardiovascular health in cancer survivors and suggest that physical activity before a diagnosis may offer enduring protection against ischemic heart disease and cardiac dysfunction.

Implications of obesity and insulin resistance for the treatment of oestrogen receptor-positive breast cancer

Breast cancer is the most common cancer in women, and incidence rates are rising, it is thought in part, due to increasing levels of obesity. Endocrine therapy (ET) remains the cornerstone of systemic therapy for early and advanced oestrogen receptor-positive (ER + ) breast cancer, but despite treatment advances, it is becoming more evident that obesity and insulin resistance are associated with worse outcomes. Here, we describe the current understanding of the relationship between both obesity and diabetes and the prevalence and outcomes for ER+ breast cancer. We also discuss the mechanisms associated with resistance to ET and the relationship to treatment toxicity.

Obesity Is an Independent Prognostic Factor That Reduced Pathological Complete Response in Operable Breast Cancer Patients

Background and Objectives: Obesity is a significant risk factor for the development of breast cancer (BC) and associated poorer outcomes. A pathological complete response (pCR) with neoadjuvant chemotherapy (NACT) correlates with improved long-term prognosis in BC patients. In this study, we aimed to investigate the predictive effect of obesity on achieving pCR following NACT. Methods: This single-center retrospective study included patients with operable BC who were treated with NACT. Patients were categorized based on their pre-chemotherapy body mass index (BMI), including non-obese (<30 kg/m2) and obese (≥30 kg/m2) groups, and pathological responses to NACT were compared. Results: A total of 191 female patients were included in this study; of these, 83 (43.4%) were obese and 108 (56.6%) were in the non-obese group. Obesity was more common in postmenopausal patients, and the median age of obese patients was significantly higher compared to non-obese patients. Patients in the obese group demonstrated significantly lower pCR rates compared to the non-obese group (30% vs. 45%, p = 0.03). The histological subtype assessment indicated that only in the HR-positive/HER2-negative patients was the pCR rate significantly lower in the obese group compared to the non-obese group (11% vs. 27%, p = 0.05). According to menopausal assessment, a significant difference in pCR rates was observed only among postmenopausal patients, with rates of 29% in the obese group compared to 52% in the non-obese group (p = 0.03). In logistic regression analysis, obesity (OR: 0.52, 95% CI: 0.28-0.97; p = 0.04) and a low Ki-67 score (HR: 2.7, 95% CI: 1.37-5.53; p = 0.003) were independently associated with a decreased rate of pCR. Conclusions: The impact of obesity on achieving pCR in BC patients undergoing NACT remains controversial. Our study revealed that obesity was an independently significant negative predictive factor for achieving pCR.

Body mass index and breast cancer risk in premenopausal and postmenopausal East Asian women: a pooled analysis of 13 cohort studies

BACKGROUND

It has been suggested that the association between body mass index and breast cancer risk differs between Asian women and Western women. We aimed to assess the associations between body mass index and breast cancer incidence in East Asian women.

METHODS

Pooled analyses were performed using individual participant data of 319,189 women from 13 cohort studies in Japan, Korea, and China. Participants' height and weight were obtained by measurement or self-reports at cohort baseline. Breast cancer was defined as code C50.0-C50.9 according to the International Classification. Using a Cox proportional hazards model, hazard ratios of breast cancer were estimated for each body mass index category, with the reference group set as the group with a body mass index of 21 to < 23 kg/m2. The hazard ratio for a 5 kg/m2 increase in body mass index was also calculated.

RESULTS

During a mean 16.6 years of follow-up, 4819 women developed breast cancer. Similar to Westerners, a steady increase in breast cancer risk with increasing body mass index was observed in postmenopausal women, but the slope of the risk increase appeared to slow at a body mass index of 26-28 kg/m2. In premenopausal women, the inverse association seen in Westerners was not observed. The risk of developing breast cancer after 50 years of age increased slightly with increasing body mass index, which was more pronounced in the older birth cohort. There was no significant association between body mass index and the risk of developing breast cancer before 50 years of age, but the risk estimates changed from positive to negative as the birth cohort got younger.

CONCLUSIONS

In East Asia, the role of body mass index in breast cancer in premenopausal women may be changing along with the increase in obesity and breast cancer. The increased risk of postmenopausal breast cancer with a higher body mass index was as robust as that of Western women.

Association between body mass index combined with high-sensitivity C-reactive protein and the risk of postmenopausal breast cancer: A prospective cohort study

The present study aimed to assess the risk of postmenopausal breast cancer in women based on a combination of body mass index (BMI) and high-sensitivity C-reactive protein (hs-CRP) levels. A total of 20,400 participants were investigated as part of the 'Kailuan Study' clinical trial. Participants were classified into four groups based on BMI (BMI ≥24 or <24 kg/m2) and hs-CRP level (hs-CRP ≥3 or <3 mg/l). Cox proportional hazards models were used to evaluate the association between the combination of BMI and hs-CRP and the risk of postmenopausal breast cancer. A total of 19,540 participants met the inclusion criteria. The median follow-up time was 14.97 years, with a cumulative follow-up period of 283,599.43 person-years. Among the participants, 269 individuals were diagnosed with postmenopausal breast cancer. Individuals with a high BMI (BMI ≥24 kg/m2) and a high hs-CRP level (hs-CRP ≥3 mg/) had a greater risk of postmenopausal breast cancer compared with individuals with a low BMI (BMI <24 kg/m2) and a low hs-CRP level (<3 mg/l) (hazard ratio, 1.75; 95% confidence interval, 1.25-2.47). The sensitivity analysis showed findings consistent with the primary results. In conclusion, the combination of high BMI and high hs-CRP level is associated with an increased risk of postmenopausal breast cancer. The present study is part of the Kailuan Study. Trial registration number: ChiCTRTNCR11001489 (Chinese Clinical Trial Registry, https://www.chictr.org.cn/showproj.html?proj=8050). Date of registration: 19/07/2015.

Changes in physical activity and diabetes risk after cancer diagnosis: a nationwide cohort study

PURPOSE

Physical activity has the potential to reduce the risk of diabetes after cancer diagnosis. However, current evidence supporting its effects is limited. This study aims to examine the associations between changes in physical activity and subsequent risk of diabetes among cancer survivors.

METHODS

A total of 264,250 cancer survivors (mean age 56.7 (12.5) years, 44.2% males) without a prior history of diabetes were assessed for adherence to physical activity both before and after their diagnosis. The primary outcome was incident diabetes. The Fine-Gray proportional sub-distribution hazards model was used to calculate sub-distribution hazard ratios (sHRs) and 95% confidence intervals (CIs) for diabetes risk, considering death as a competing risk.

RESULTS

Over a follow-up of 1,065,802 person-years, maintaining regular physical activity from pre-diagnosis was associated with a 10% reduced risk of diabetes after cancer diagnosis (sHR 0.90, 95% CI 0.85-0.96), considering traditional diabetes risk factors, sociodemographics, and primary cancer sites. Cancer survivors who became active and inactive after their cancer diagnosis exhibited a marginally decreased risk of diabetes (sHR 0.98, 95% CI 0.93-1.03; sHR 0.97, 95% CI 0.92-1.03). The strength and direction of the association varied depending on the primary site of cancer.

CONCLUSIONS

Regular physical activity starting before a cancer diagnosis is associated with a lower risk of diabetes following the diagnosis, independent of established diabetes risk factors.

IMPLICATIONS FOR CANCER SURVIVORS

The study underscores the importance of engaging in sufficient physical activity to mitigate the risk of diabetes in cancer survivors.

Adiposity, Body Composition Measures, and Breast Cancer Risk in Korean Premenopausal Women

Objective

To investigate the association between body composition parameters and breast cancer (BC) risk in premenopausal women.

Design, Setting, and Participants

Prospective cohort study using data from the Kangbuk Samsung Cohort Study. Participants were women aged 20 to 54 years who were enrolled from 2011 to 2019 and followed up for BC development until December 31, 2020. Data were analyzed from June to August 2023.

Exposures

Trained nurses conducted anthropometric measurements and assessed body composition using segmental bioelectric impedance analysis. The analysis encompassed adiposity measures such as body mass index (BMI), waist circumference, and body composition parameters, including muscle mass, fat mass, ratio of muscle mass to weight, ratio of fat mass to weight, and fat mass index.

Main outcomes and measures

Adjusted hazard ratios (aHR) for BC during the follow-up period.

Results

Among 125 188 premenopausal women, the mean (SD) age was 34.9 (6.3) years. During a mean (range) follow-up of 6.7 (0.5-9.9) years, 1110 incident BC cases were identified. The mean (SD) BMI and waist circumference were 21.6 (3.1) and 75.3 (8.2) cm, respectively. Higher BMI and waist circumference were associated with decreased risk, with an aHR of 0.89 (95% CI, 0.84-0.95) per SD increase in BMI and 0.92 (95% CI, 0.86-0.98) per SD increase in waist circumference. A higher ratio of fat mass to weight was associated with decreased BC risk (aHR, 0.92; 95% CI, 0.86-0.99 per SD increase), whereas the opposite trend was observed for the ratio of muscle mass to weight, with an aHR of 1.08 (95% CI, 1.02-1.15) per SD increase. The results remained consistent even after additional adjustments for height in the model. The fat mass index was also inversely associated with BC risk, with an HR of 0.90 (95% CI, 0.85-0.97) per SD increase.

Conclusions and Relevance

In this cohort study of premenopausal women, a higher level of adiposity, represented by increased BMI, waist circumference, and fat mass, was consistently associated with decreased breast cancer risk. Conversely, muscle mass and its ratio to weight displayed opposite or inconsistent patterns. These findings suggest an inverse association between excess adiposity and the risk of BC in premenopausal women, confirming earlier findings that BMI is an indirect measure of adiposity.

Interaction between body mass index and family history of cancer on the risk of female breast cancer

Both body mass index (BMI) and family history of cancer are established risk factors for female breast cancer. However, few studies explored the potential interaction between both factors. We assessed the association of BMI and its interaction with family cancer history on the risk of female breast cancer in Shanghai, China. Based on a population-based prospective cohort study started from 2008 to 2012 with 15,055 Chinese female participants in Minhang district, Shanghai. Cox regression models were used to estimate the association of BMI and its interaction with a family history of cancer on breast cancer risk. The additive interaction was evaluated by the relative excess risk due to interaction (RERI) and the attributable proportion due to interaction (AP), and the multiplicative interaction was assessed by the product term (BMI* family history of cancer) in the Cox regression model. Compared with BMI of < 24 kg/m2 and no family history of cancer, women with BMI of ≥ 24 kg/m2 and a family history of cancer had a higher risk for breast cancer with HR 2.06 (95% CI 1.39, 3.06). There was an additive interaction between BMI and family history of cancer on breast cancer incidence, with the RERI being 0.29 (95% CI 0.08, 0.51) and the AP being 0.37 (95% CI 0.08, 0.66). The coexistence of obesity and cancer family history may exacerbate breast cancer incidence risk, highlighting the importance of weight management in women with a family history of cancer.

Breast cancer risk association with postmenopausal hormone therapy: Health Insurance Database in South Korea-based cohort study

CONTEXT

Although many physicians have been concerned that the menopausal hormones used currently in clinical practice may affect the risk of breast cancer, there are currently few informative updated studies about the associations between menopausal hormone therapy (MHT) and the risk of breast cancer.

OBJECTIVE

This study aims to evaluate the association between the risk of breast cancer and MHT using the National Health Insurance Database in South Korea (HISK) cohort between 2002 and 2019 retrospectively.

METHODS

Postmenopausal women over 40 years of age from 2003 to 2011 were selected as the subject population, and their follow-up data were collected until 2019. We analyzed the risk and mortality of breast cancer according to the type of MHT received, namely, tibolone, combined estrogen plus progestin by manufacturer (CEPM), oral estrogen, combined estrogen plus progestin by physician (CEPP), or topical estrogen.

RESULTS

The risk of breast cancer increased in the CEPM group [hazard ratio (HR) 1.439, 95% CI 1.374-1.507, P-value < .001] in comparison with the non-MHT group. However, no significant associations were found between the use of tibolone, oral estrogen, CEPP, or topical estrogen and breast cancer risk in comparison with the non-MHT group (HR 0.968, 95% CI 0.925-1.012; HR 1.002, 95% CI 0.929-1.081; HR 0.929, 95% CI 0.75-1.15; HR 1.139, 95% CI 0.809-1.603). The mortality rate from breast cancer is lower in the MHT group in comparison with the non-MHT group, indicating that significant associations were found for tibolone, CEPM, and oral estrogen (HR 0.504, 95% CI 0.432-0.588; HR 0.429, 95% CI 0.352-0.522; HR 0.453 95% CI 0.349-0.588, P-value < .001).

CONCLUSIONS

This study suggests that the risk of breast cancer is increased by drugs in the CEPM group but not by tibolone, oral estrogen, CEPP, or topical estrogen. The mortality rate from breast cancer is lower with MHT (tibolone, CEPM, oral estrogen) than without MHT.

The effects of women's insight levels on breast cancer prevention behaviors: a cross-sectional study

The aim of this study is to determine the effect of women's insight levels on their breast cancer prevention behaviors in primary health care services. A systematic sampling method was used to select a sample of 393 women in a province in Turkey. Socio-demographic Characteristics Form, Insight Scale and Scale for Determining Factors Affecting Women's Breast Cancer Prevention Behaviour were used as data collection tools. Data were collected face-to-face and then analyzed statistically using Student's t-test, one-way analysis of variance, Tukey HSD, Spearman correlation test and multiple regression analysis. The results showed that those who felt "healthy" had significantly higher mean breast cancer prevention behavior (p < .05). It was determined that there was a weak positive correlation between the level of insight and breast cancer prevention behaviors, and the increase in the level of insight had a significant positive effect of 0.37 ± 0.051 points on breast cancer prevention behaviors. It was found that there was a significant negative effect on prevention behaviors with 1.66 ± 0.796 points in those with a high education level and 1.58 ± 0.505 points in those with suspected disease. In conclusion, in this study, it was determined that insight level, education level, and awareness of early diagnosis affected the prevention behaviors of breast cancer.

Changes in body composition and subsequent cardiovascular disease risk among 5-year breast cancer survivors

Introduction

Cardiovascular disease (CVD) remains a leading cause of death in breast cancer survivors, a growing population. The aim of this study was to determine whether changes in body composition, commonly observed in breast cancer survivors, is associated with subsequent CVD risk.

Methods

This cohort study used the Korean National Health Insurance Service database. The study population included 73,271 5-year breast cancer survivors aged 40 years or above. To assess changes in body composition and its effect on the risk of CVD, validated prediction equations and multivariate Cox proportional hazards regression were used. Changes in metabolic markers (blood pressure, total cholesterol, and fasting serum glucose) according to changes in body composition were calculated by multiple linear regression.

Results

Having persistently high predicted lean body and appendicular skeletal muscle mass percentages (LBMP and ASMP, respectively) among breast cancer survivors was associated with 32% and 40% lower CVD risks than a persistently low predicted LBMP or ASMP, respectively. Conversely, persistently high predicted body fat mass percentage (BFMP) was associated with a higher CVD risk than persistently low predicted BFMP. Additionally, those with a low to high change in predicted BFMP had a higher risk of CVD than those with persistently low predicted BFMP. Changes in body composition were accompanied by changes in metabolic markers.

Discussion

Maintaining high percentages of lean body and appendicular skeletal muscle mass and preventing an increase in fat mass may be beneficial in preventing CVD in breast cancer survivors.

The relationship between central obesity and risk of breast cancer: a dose-response meta-analysis of 7,989,315 women

Purpose

Central obesity may contribute to breast cancer (BC); however, there is no dose-response relationship. This meta-analysis examined the effects of central obesity on BC and their potential dose-response relationship.

Methods

In the present study, PubMed, Medline, Embase, and Web of Science were searched on 1 August 2022 for published articles. We included the prospective cohort and case-control studies that reported the relationship between central obesity and BC. Summary effect size estimates were expressed as risk ratios (RRs) or odds ratios (ORs) with 95% confidence intervals (95% CI) and were evaluated using random-effect models. The inconsistency index (I2) was used to quantify the heterogeneity magnitude derived from the random-effects Mantel-Haenszel model.

Results

This meta-analysis included 57 studies (26 case-control and 31 prospective cohort) as of August 2022. Case-control studies indicated that waist circumference (WC) (adjusted OR = 1.18; 95% CI: 1.00-1.38; P = 0.051) and waist-to-hip ratio (WHR) (adjusted OR = 1.28; 95% CI: 1.07-1.53; P = 0.008) were significantly positively related to BC. Subgroup analysis showed that central obesity measured by WC increased the premenopausal (adjusted OR = 1.15; 95% CI: 0.99-1.34; P = 0.063) and postmenopausal (adjusted OR = 1.18; 95% CI: 1.03-1.36; P = 0.018) BC risk and the same relationship appeared in WHR between premenopausal (adjusted OR = 1.38; 95% CI: 1.19-1.59; P < 0.001) and postmenopausal (adjusted OR = 1.41; 95% CI: 1.22-1.64; P < 0.001). The same relationship was observed in hormone receptor-positive (HR+) (adjusted ORWC = 1.26; 95% CI: 1.02-1.57; P = 0.035, adjusted ORWHR = 1.41; 95% CI: 1.00-1.98; P = 0.051) and hormone receptor-negative (HR-) (adjusted ORWC = 1.44; 95% CI: 1.13-1.83; P = 0.003, adjusted ORWHR = 1.42; 95% CI: 0.95-2.13; P = 0.087) BCs. Prospective cohort studies indicated that high WC (adjusted RR = 1.12; 95% CI: 1.08-1.16; P < 0.001) and WHR (adjusted RR = 1.05; 95% CI: 1.018-1.09; P = 0.017) may increase BC risk. Subgroup analysis demonstrated a significant correlation during premenopausal (adjusted RR = 1.08; 95% CI: 1.02-1.14; P = 0.007) and postmenopausal (adjusted RR = 1.14; 95% CI: 1.10-1.19; P < 0.001) between BC and central obesity measured by WC, and WHR was significantly positively related to BC both premenopausal (adjusted RRpre = 1.04; 95% CI: 0.98-1.11; P = 0.169) and postmenopausal (adjusted RRpost = 1.04; 95% CI: 1.02-1.07; P = 0.002). Regarding molecular subtype, central obesity was significantly associated with HR+ (adjusted ORWC = 1.13; 95% CI: 1.07-1.19; P < 0.001, adjusted ORWHR = 1.03; 95% CI: 0.98-1.07; P = 0.244) and HR- BCs (adjusted ORWC =1.11; 95% CI: 0.99-1.24; P = 0.086, adjusted ORWHR =1.01; 95% CI: 0.91-1.13; P = 0.808). Our dose-response analysis revealed a J-shaped trend in the relationship between central obesity and BC (measured by WC and WHR) in case-control studies and an inverted J-shaped trend between BMI (during premenopausal) and BC in the prospective cohort.

Conclusion

Central obesity is a risk factor for premenopausal and postmenopausal BC, and WC and WHR may predict it. Regarding the BC subtype, central obesity is proven to be a risk of ER+ and ER- BCs. The dose-response analysis revealed that when BMI (during premenopausal) exceeded 23.40 kg/m2, the risk of BC began to decrease, and WC higher than 83.80 cm or WHR exceeded 0.78 could efficiently increase the BC risk.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/, identifier: CRD42022365788.

Alcohol consumption and the risk of new-onset uterine leiomyomas: a nationwide population-based study in 2.5 million Korean women aged 20 to 39 years

BACKGROUND

Uterine leiomyomas are the most common benign tumors in women of childbearing age. Although there are several studies reporting the positive association of drinking alcohol with the incidence of uterine leiomyomas, studies targeting Korean women are lacking.

OBJECTIVE

This study aimed to investigate the association between alcohol consumption and the risk of new-onset uterine leiomyomas in Korean women of early reproductive-age.

STUDY DESIGN

This was a retrospective nationwide population-based cohort study using the Korean National Health Insurance Service database. Participants comprised 2,512,384 asymptomatic Korean women aged 20 to 39 years who underwent a national health examination from 2009 to 2012. The follow-up period was from the date of the first national health examination to the date of diagnosis of new-onset uterine leiomyomas or December 2018 if no uterine leiomyomas were detected. The diagnosis of uterine leiomyomas required 2 outpatient records within a year or 1 inpatient record of International Classification of Diseases, Tenth Revision (ICD-10) codes of uterine leiomyomas (D25) in the Korean National Health Insurance Service. Exclusion criteria were previously diagnosed uterine leiomyomas during the screening period (January 2002 to the date of first health examination) or uterine leiomyoma diagnosis within 1 year of baseline examination. The associations of alcohol consumption, amount drunk per drinking session, and sustained drinking over time with the risk of new-onset uterine leiomyomas were investigated.

RESULTS

Approximately 6.1% of women aged 20 to 39 years were diagnosed with uterine leiomyomas after an average of 4.3 years. Alcohol consumption was associated with an increased incidence of new-onset uterine leiomyomas of 12% to 16% (hazard ratio, 1.12; 95% confidence interval, 1.11-1.14 for mild-to-moderate drinkers; hazard ratio, 1.16; 95% confidence interval, 1.12-1.20 for heavy drinkers). Drinking ≥1 days per week was associated with increased risk of uterine leiomyomas (hazard ratio, 1.11; 95% confidence interval, 1.10-1.12 for drinking 1 day per week; hazard ratio, 1.15; 95% confidence interval, 1.12-1.17 for drinking ≥3 days per week), and the association increased proportionately to the amount of alcohol consumed per drinking session (hazard ratio, 1.17; 95% confidence interval, 1.15-1.19 for ≥7 glasses per drinking session). Women who also reported alcohol consumption in the questionnaire administered 2 years later (sustained drinkers) exhibited a 20% increased risk of new-onset uterine leiomyomas (hazard ratio, 1.20; 95% confidence interval, 1.17-1.22) compared with women who answered that they did not drink alcohol at both times (sustained nondrinkers). In women who discontinued drinking, the risk was 3% (hazard ratio, 1.03; 95% confidence interval, 1.01-1.06), whereas in women who became drinkers, the risk was 14% (hazard ratio, 1.14; 95% confidence interval, 1.11-1.16).

CONCLUSION

Having an alcohol drinking habit, the amount of alcohol consumed per drinking session, and sustained drinking over 2 years were significantly associated with the risk of new-onset uterine leiomyomas. Avoiding or discontinuing drinking could lower the risk of new-onset uterine leiomyomas in early reproductive-age women.

Dietary Heat-Treatment Contaminants Exposure and Cancer: A Case Study from Turkey

In this study, the 10-year dietary habits of patients diagnosed with cancer (n = 1155) were retrospectively analyzed, and the relationships between dietary (red meat, white meat, fish meat, French fries, bread, instant coffee, ready-to-drink coffee, Turkish coffee, and black tea) heterocyclic amines, polycyclic aromatic hydrocarbons, acrylamide, and N-nitrosamine-based risk scores and cancer types were statistically evaluated. The foods with the highest and lowest mean dietary heat-treatment contaminant risk scores were red meat and ready-to-drink coffee, respectively. There were statistically significant differences in the dietary heat-treatment contamination risk scores based on the cancer patients' demographic characteristics (sex, age, smoking, and body mass index) (p < 0.05). According to the cancer types, the systems with the highest and lowest dietary heat-treatment contaminant risk scores were determined as other (brain, thyroid, lymphatic malignancies, skin, oro- and hypopharynx, and hematology) and the reproductive (breast, uterus, and ovary) system, respectively. The relationship between instant coffee consumption and respiratory system cancer types, the frequency of consumption of French fries and urinary system cancer types and the consumption of meat products and gastrointestinal system cancer types were determined. It is thought that this study contains important findings regarding the relationship between dietary habits and cancer and will be a good source for other studies to be conducted in this context.

Development and Modification of a Culturally Tailored Education Program to Prevent Breast Cancer in Korean Immigrant Women in New York City

Breast cancer (BC) is the most common cancer in Korean American (KA) women. In view of its high prevalence in these women, their low screening rates, and the cultural influence of BC risk factors in their lifestyles, we developed a community-based culturally tailored BC prevention program, the Korean Breast Cancer Risk Reduction Program (KBCRRP). Guided by the PRECEDE-PROCEDE and health belief models, the KBCRRP was developed to achieve four goals: (1) healthy weight, (2) physically active lifestyle, (3) healthy diet, and (4) BC screening and adherence. KBCRRP combines effective multicomponent strategies for BC screening and a group-based lifestyle intervention incorporating traditional Korean health beliefs and is tailored for BC risk reduction. In this paper, we provide an overview of the program, the process of program development, implementation, and evaluation, and modification during the COVID-19 pandemic. The initial program involved 8 weeks of in-person group education sessions led by interdisciplinary healthcare professionals and 16 weeks of follow-up involving smartphone applications, phone calls, and text messaging from trained lifestyle coaches. Participants received opportunities to obtain free mammography during the program. After feasibility testing, the program was modified by incorporating participants' feedback. During the COVID-19 pandemic, we provided the program using the Zoom video platform. Participants' recruitment and retention during the pandemic was successful, reflecting the fact that virtual delivery of group-based education was a feasible and acceptable alternative to in-person sessions. Collaboration with community organizations serving the target population is the key to developing and sustaining a successful community-based educational program.

Trend of disease burden and risk factors of breast cancer in developing countries and territories, from 1990 to 2019: Results from the Global Burden of Disease Study 2019

Background

The incidence, mortality, burden of disability-adjusted life years (DALYs), and attributable risk factors of breast cancer vary significantly by country or region, particularly between developing and developed countries. This study aimed to analyze breast cancer development trends in developing countries based on the influence of the different sociodemographic indices (SDIs) and World Bank (WB) income-level disease data from 1990 to 2019.

Methods

Data on the annual incidence, mortality, DALY, years of life lost (YLL) prematurely, years lived with disability (YLD), and age-standardized rate (ASR) of breast cancer from 1990 to 2019 in different countries and territories were obtained from the 2019 Global Burden of Disease (GBD) Study. A comparative risk assessment (CRA) framework was used to analyze the general risk factors.

Results

The global age-standardized incidence rate (ASIR) gradually increased from 21.44 per 100,000 population in 1990 to 24.17 per 100,000 population in 2019. It rose precipitously to 2.91- and 2.49-fold, respectively, for countries with middle SDIs and low-middle SDIs. The ASIR of breast cancer was increasing in the lower-middle-income levels in WB, with an estimated annual percentage change (EAPC) of 0.29 [95% uncertainty interval (UI): 0.20-0.37] and reduced income (EAPC of 0.59 [95% UI: 0.53-0.65]). The Solomon Islands and the United Arab Emirates observed the most significant increase in the magnitude of deaths from breast cancer cases. Compared to the death cases of 1990, percentage changes increased separately by 1,169 and 851%. Compared to developed areas, breast cancer-related deaths increased rapidly in developing regions, especially among the middle-aged and elderly groups. Meanwhile, the long-term burden of breast cancer was ever expanding. Of all the GBD regions, Oceania had the youngest age distribution. The deaths in the young and middle-aged groups accounted for 69% in 1990 and 72% in 2019. Percentage changes in deaths from the seven risk factors in low- to middle-SDI regions increased significantly over time across all age groups. However, a diet with high red meat and high body mass index (BMI) accounted for the most considerable increase in the magnitude.

Conclusion

Public health policy regarding breast cancer is fundamental in low- and medium-income countries. The development and adoption of cost-effective screening and therapeutic solutions, the mitigation of risk factors, and the establishment of a cancer infrastructure are essential.

Adipocytokine imbalance and breast cancer in obese women

CONTEXT

Breast cancer is the most common diagnosis established in women with malignant tumors.

AIMS

The purpose is to investigate the blood contents of adiponectin and leptin in women with breast cancer and obesity.

SETTINGS AND DESIGN

A total of 140 women aged 40-50 were examined.

MATERIALS AND METHODS

Group 1 included 70 women from classes 1 or 2 obesity. Group 2 included 70 women with stage 1 or 2 breast cancer and classes 1 or 2 obesity. The control group included 30 apparently healthy women, with mean age of 42.5 ± 2.5 years.

STATISTICAL ANALYSIS USED

Statistical processing of the results obtained was performed using Statistica.

RESULTS

Groups 1 and 2 were statistically significantly different from each other across all parameters, except for leptin resistance. In group 2, the course of breast cancer with concomitant obesity is characterized by disrupted adipocytokine homeostasis, which manifests as a 1.94-fold decrease in the blood content of adiponectin (P < 0.05), a 4.14-fold increase in the blood content of leptin (P < 0.05), and an 8.00-fold increase in the leptin/adiponectin ratio (P < 0.05). Poorly differentiated breast tumors exhibit a more pronounced imbalance in the blood levels of adipocytokines. Thus, the serum content of leptin in women with poorly differentiated tumors (G3) was 1.79 times (P < 0.05) higher than in women with moderately differentiated tumors (G2).

CONCLUSIONS

The course of breast cancer with concomitant obesity is characterized by disrupted adipocytokine homeostasis and decreased adiponectin concentration in the blood.

Healthy Lifestyle and Breast Cancer Risk in Palestinian Women: A Case-Control Study

The aim of this study was to investigate the association between a combined healthy lifestyle score and the risk of breast cancer (BC) in Palestinian women. A hospital-based case-control study compared 237 BC cases with confirmed diagnoses to 237 healthy controls. Women's lifestyle components were assessed using a validated questionnaire. A healthy lifestyle index (HLI) has been developed. We used logistic regression models to investigate the relationship between combined lifestyle scores and BC odds. The results revealed that HLI was significantly higher in the control group than in the study group. A higher HLI score was associated with a lower risk of BC in the multivariate analysis. The adjusted odds ratios (AOR) were 0.19 for all women, 0.15 for postmenopausal women, and 0.23 for premenopausal women when the HLI highest and lowest tertiles were compared. HLI score increases of one point resulted in a 41% reduction in the risk of BC for all women, a 42% reduction for postmenopausal and premenopausal women, and a 39% reduction for postmenopausal women. Women who live a healthy lifestyle, according to our findings, have a lower risk of breast cancer. BC prevention programs must promote long-term healthy food and lifestyle choices.

Spatiotemporal distribution and determinants of overweight or obesity among urban women in Ethiopia: a multivariate decomposition analysis

BACKGROUND

Overweight /obesity is a global public health concern. It is higher among women than men in most continents of the world. This study aimed to determine the spatiotemporal distribution and determinants of changes in overweight/obesity over time among urban women in Ethiopia.

METHODS

We used data from three consecutive Demographic and Health Surveys in Ethiopia (2005, 2011, and 2016). The total weighted sample of 1112 in 2005, 3569 in 2011, and 3071 in 2016 urban women were included in the analysis. The primary outcome measure of this study was the spatiotemporal distribution and trends over time in overweight/obesity. Factors contributing to change in overweight/obesity were examined using a logit-based multivariate decomposition analysis.

RESULTS

Overweight/obesity increased from 14.2% in 2005 to 21% in 2016. Approximately 61.3% of the overall increase in overweight/obesity among urban women was due to the difference in coefficient (difference in the effect of characteristics) across the surveys. Changes in the composition of women aged 25-49 years (β = 0.012, 95% CI 0.008, 0.015), married women (β = 0.010, 95% CI 0.006, 0.014), women with formal education (primary: β = 0.007, 95% CI 0.003, 0.011, higher education: β = 0.014, 95% CI 0.006, 0.022), women with formal employment (β = 0.006, 95% CI 0.001, 0.011), and women with informal employment (β = - 0.002, 95% CI - 0.003, - 0.0004) were factors contributing to the change in overweight/obesity from 2005 to 2016. The risk difference (RD) in women's overweight/obesity significantly varied across regions in urban Ethiopia. Furthermore, a high proportion of overweight/obesity was found mainly in Tigray, Oromia, Amhara, and Addis Ababa.

CONCLUSIONS

The rate of overweight/obesity among women in urban Ethiopia has shown a significant increase over the last 11 years. This rate change was due to changes in the composition of women's age, educational status, marital status, and employment status. Therefore, program interventions should be targeted at older (> 25 years), educated, married, Addis Ababa residents, and formally employed women.

Identification of FOXM1 and CXCR4 as key genes in breast cancer prevention and prognosis after intermittent energy restriction through bioinformatics and functional analyses

We explored potential biomarkers and molecular mechanisms regarding breast cancer (BC) risk reduction after intermittent energy restriction (IER) and further explored the association between IER and BC prognosis. We identified differentially expressed genes (DEGs) in breast tissues before and after IER by analyzing the expression profile from GEO. Then, enrichment analysis was used to identify important pathways of DEGs and hub genes were selected from PPI network. After that, GEPIA, ROC, and KM plotter were used to explore the preventive and prognostic value of hub genes. It was found that FOXM1 and CXCR4 were highly expressed in BC tissues and associated with the worse prognosis. FOXM1 and CXCR4 were down-regulated after IER , which meant that FOXM1 and CXCR4 might be the most important key genes for reducing the risk and improving prognosis of BC after IER . ROC curve indicated that FOXM1 and CXCR4 also had the predictive value for BC. Our study contributed to a better understanding of the specific mechanisms in protective effects of IER on BC and provided a new approach to improve the prognosis of BC, which might provide partial guidance for the subsequent development of more effective treatments and prevention strategies.

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.

Consecutive gain and loss in body weight and waist circumference with risk of subsequent breast cancer in Korean women

BACKGROUND

This study investigated the association between longitudinal changes in weight and waist circumference and breast cancer risk according to menopausal status.

METHODS

This retrospective cohort study used data from the population-based Korean National Health Insurance Service (NHI) database. The study population included women aged ≥40 years who consecutively underwent three biennial breast cancer screenings between 2009-2014 and were followed up until 2020. The percentage changes in weight and waist circumference during the three screenings were calculated and categorized into five groups based on the level of increase or decrease in these two factors. Hazard ratios (HRs) and 95% confidence intervals (95% CI) for breast cancer risk were calculated and adjusted for other factors.

RESULTS

Of 691,253 premenopausal and 1,519,211 postmenopausal women, 9485 and 12,553 breast cancer cases were identified, respectively, during a median 6.9 follow-up years. Postmenopausal women with two consecutive weight gains had an increased risk of breast cancer risk (HR = 1.11, 95% CI = 1.01 to 1.22); meanwhile, consecutive weight loss was associated with a decreased risk (HR = 0.84, 95% CI = 0.76 to 0.93). Single time and continuous decreases in waist circumference were associated with a decreased risk (HR = 0.91, 95% CI = 0.85 to 0.98, and HR = 0.84, 95% CI = 0.76-0.93), while single time and continuous increases were associated with an increased risk (HR = 1.08, 95% CI = 1.01 to 1.15, and HR = 1.13, 95% CI = 1.04 to 1.22). Single weight gain was associated with the increased breast cancer risk in premenopausal women (HR = 1.07, 95% CI = 1.01 1.13).

CONCLUSIONS

Our findings suggest a dose-response relationship between weight, waist circumference change, and the risk of future breast 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.

Bariatric Surgery and Breast Cancer Incidence: a Population-Based, Matched Cohort Study

PURPOSE

Obesity is associated with increased breast cancer risk in women. Bariatric surgery induces substantial weight loss. However, the effects of such weight loss on subsequent breast cancer risk in women with obesity are poorly understood. To examine breast cancer incidence and related outcomes in women with obesity undergoing bariatric surgery.

MATERIALS AND METHODS

This was a population-based matched cohort study of breast surgery outcomes utilizing linked clinical databases in Ontario, Canada. Women with obesity who underwent bariatric surgery were 1:1 matched using a propensity score to non-surgical controls for age and breast cancer screening history. The main outcomes were incidence of breast cancer after lag periods of 1, 2, and 5 years. Additional outcomes included tumor hormone receptor status, cancer stage, and treatments undertaken. Time-varying Cox proportional hazard models accounting for screening during follow-up were used to model cancer incidence.

RESULTS

A total of 12,724 women per group were included, average age 45.09. After a 1-year lag, breast cancer incidence occurred in 1.09% and 0.79% of the control and surgery groups, respectively (adjusted hazard ratio, 0.81 [95%CI 0.69-0.95]; p = 0.01). This association was maintained after lag periods of 2 and 5 years. Women in the surgical cohort diagnosed with breast cancer were more likely to have low-grade tumors and less likely to have high-grade tumors (overall p < 0.01). No association was found for tumor hormone receptor status, although the surgical group was more likely to have her2neu-negative tumors (p = 0.01).

CONCLUSION

Bariatric surgery was associated with a lower incidence of breast cancer and lower tumor grade in women with obesity. Further evaluation of outcomes, including mortality, is required.

Insulin resistance and the development of breast cancer in premenopausal women: the Kangbuk Samsung Health Study

PURPOSE

Research on the role of insulin resistance (IR) in breast cancer risk in premenopausal women is scarce. We aimed to investigate the relationship between IR and the development of breast cancer in premenopausal women.

METHODS

We analyzed the prospective association of IR and incident breast cancer in premenopausal women without breast cancer at baseline using a subsample of the Kangbuk Samsung Health Study.

RESULTS

Among 134,488 Korean premenopausal women, 696 women developed incident breast cancers during a median follow-up of 4.34 years. After adjustment for dense breast and other potential confounders, HR (95% CI) for incident breast cancer comparing HOMA-IR quintiles 2, 3, 4, and 5 to the first quintile was 0.91 (0.71-1.17), 0.89 (0.69-1.15), 0.75 (0.57-0.98), and 0.87 (0.65-1.16), respectively (P for trend = 0.117), while HR (95% CI) comparing insulin quintiles 2, 3, 4, and 5 to the first quintile was 1.02 (0.80-1.30), 0.90 (0.69-1.16), 0.72 (0.54-0.96), and 0.96 (0.72-1.28), respectively (P for trend = 0.151). This pattern did not significantly differ by obesity. These results were attenuated and no longer significant in time-dependent analyses where updated status of insulin and other covariates over time were treated as time-varying covariates.

CONCLUSION

Our findings do not support the positive relationship of IR with the development of breast cancer in premenopausal women, unlike in postmenopausal women. Thus, the role of IR as a risk factor for breast cancer may differ by menopausal status.

Cancer Etiology and Prevention Principle: "1 + X"

Cancer was previously thought to be an inevitable aspect of human health with no effective treatments. However, the results of in-depth cancer research suggest that most types of cancer may be preventable. Therefore, a comprehensive understanding of the disparities in cancer burden caused by different risk factors is essential to inform and improve cancer prevention and control. Here, we propose the cancer etiology and prevention principle "1 + X," where 1 denotes the primary risk factor for a cancer and X represents the secondary contributing risk factors for the cancer. We elaborate upon the "1 + X" principle with respect to risk factors for several different cancer types. The "1 + X" principle can be used for precise prevention of cancer by eliminating the main cause of a cancer and minimizing the contributing factors at the same time.

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.

Enhanced Susceptibility to Breast Cancer in Korean Women With Elevated Serum Gamma-Glutamyltransferase Levels: A Nationwide Population-Based Cohort Study

BACKGROUND

The incidence of breast cancer has been gradually increasing in Korea. Recently, the elevated level of serum gamma-glutamyltransferase (GGT) has emerged to be associated with the development and progression of some malignancies. This study aimed to determine the effect of serum GGT levels on the risk of developing breast cancer in Korean women.

METHODS

We used National Health Insurance Service Health Checkup data to examine the association between serum GGT levels and breast cancer development in Korean women. Women aged 40 years or older who participated in the Korean National Health Screening Examination between January 2009 and December 2009 and who did not develop any cancer within 1-year post examination were included in this analysis (n = 3,109,506). Cox proportional hazard regression analysis was conducted to calculate hazard ratios (HRs) with 95% confidence intervals (CIs).

RESULTS

Overall, an elevated serum GGT level was associated with the increased risk of developing breast cancer; compared to the Q1 group, the Q4 group showed a significantly increased breast cancer risk (HR: 1.120,95% CI: 1.08-1.162). Such a relationship was stronger in post-menopausal women than pre-menopausal women (HR: 1.173, 95% CI: 1.107-1.243; HR: 1.070, 95% CI:1.019-1.124). Women with a high GGT level (Q4) were also at an increased risk of developing carcinoma in situ (CIS) (HR: 1.114, 95% CI: 1.04-1.192). In post-menopausal women, the Q4 group also exhibited higher CIS risk (HR: 1.266, 95% CI: 1.132-1.416). However, no significant difference in the risk of developing CIS was observed between the Q1 and Q4 groups in pre-menopausal women. Further analysis revealed that obese, post-menopausal women with a high GGT level (Q4) were associated with an increased risk of developing breast cancer (HR: 1.214, 95% CI: 1.125-1.31) and CIS (HR: 1.348, 95% CI: 1.159-1.569).

CONCLUSIONS

Our study results demonstrate that increased serum GGT level is a risk factor for developing breast cancer. The post-menopausal women group with obesity and elevated serum GGT level showed the highest incidence of breast cancer. Thus, serum GGT concentration could be a novel and potential risk factor for breast cancer. Further validation in different ethnic groups would be warranted.

Examination of incidence, mortality and disability-adjusted life years and risk factors of breast cancer in 49 Asian countries, 1990-2019: estimates from Global Burden of Disease Study 2019

BACKGROUND

This study presents an up-to-date, comprehensive and comparative examination of breast cancer's temporal patterns in females in Asia in last three decades.

METHODS

The estimates of incidence, mortality, disability-adjusted-life-years and risk factors of breast cancer in females in 49 Asian countries were retrieved from Global Burden of Disease 2019 study.

RESULTS

In Asia, female breast cancer incidence grew from 245 045[226 259-265 260] in 1990 to 914 878[815 789-1025 502] in 2019 with age-standardized incidence rate rising from 21.2/100 000[19.6-22.9] to 35.9/100 000[32.0-40.2] between 1990 and 2019. The death counts more than doubled from 136 665[126 094-148 380] to 337 822[301 454-375 251]. The age-standardized mortality rate rose marginally between 1990 and 2019 (1990: 12.1[11.0-13.1]; 2019: 13.4[12.0-14.9]). In 2019, age-standardized incidence rate varied from 17.2/100 000[13.95-21.4] in Mongolia to 122.5[92.1-160.7] in Lebanon and the age-standardized mortality rate varied 4-fold from 8.0/100 000 [7.2-8.8] in South Korea to 51.9[39.0-69.8] in Pakistan. High body mass index (5.6%), high fasting plasma glucose (5.6%) and secondhand smoke (3.5%) were the main contributory risk factors to all-age disability-adjusted-life-years due to breast cancer in Asia.

CONCLUSION

With growing incidence, escalating dietary and behavioural risk factors and lower survival rates due to late-disease presentation in low- and medium-income countries of Asia, breast cancer has become a significant public health threat. Its rising burden calls for increasing breast cancer awareness, preventive measures, early-stage detection and cost-effective therapeutics in Asia.

Relationship between body mass index and malignancy rates of MRI-guided breast biopsies: impact of clinicodemographic factors

PURPOSE

To determine the positive predictive value (PPV) of magnetic resonance imaging (MRI)-guided breast biopsy stratified by body mass index (BMI). Secondary endpoints include evaluation of indications for breast MRI and identification of factors associated with malignant biopsy.

METHODS

We retrospectively analyzed results of MRI-guided breast biopsies in a consecutive cohort of women at a single institution between 2014 and 2019. The PPV was compared between BMI subgroups and the overall group by the one-sample z-test. Factors associated with malignant biopsy were analyzed using multivariate regression analysis.

RESULTS

Among 427 MRI-guided breast biopsies, the PPV was significantly higher in patients with a BMI ≥ 35 compared to BMI < 35 (38.6% versus 24.5%, p = 0.043). This remained true in the 180 biopsies from high-risk screening studies, but there was no difference in PPV by BMI in the 205 biopsies performed to evaluate extent of known disease. Among this cohort who underwent MRI-guided breast biopsy, the underlying indication for MRI was less likely to be high-risk screening in those with a higher BMI or Black or Hispanic race (p = 0.015 and p < 0.001, respectively). For high-risk screening studies, only BMI ≥ 35 was associated with malignant biopsies (OR 37.5, p = 0.003). For evaluation of extent of disease studies, only increased lesion size was a significant predictor of malignant result (OR 1.01, p = 0.04).

CONCLUSIONS

Among women who underwent MRI-guided breast biopsy, elevated BMI was associated with increased PPV and malignant biopsies. Patients with a higher BMI or Black or Hispanic race who had MRI-guided biopsy were less likely to be undergoing high-risk screening and more likely to have breast MRI to evaluate extent of known disease.

Changes in Metabolic Syndrome Status and Breast Cancer Risk: A Nationwide Cohort Study

OBJECTIVE

To our knowledge, no studies have yet looked at how the risk of developing breast cancer (BC) varies with changes in metabolic syndrome (MetS) status. This study aimed to investigate the association between changes in MetS and subsequent BC occurrence.

RESEARCH DESIGN AND METHODS

We enrolled 930,055 postmenopausal women aged 40-74 years who participated in a biennial National Health Screening Program in 2009-2010 and 2011-2012. Participants were categorized into four groups according to change in MetS status during the two-year interval screening: sustained non-MetS, transition to MetS, transition to non-MetS, and sustained MetS. We calculated multivariable-adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs) for BC incidence using the Cox proportional hazards models.

RESULTS

At baseline, MetS was associated with a significantly increased risk of BC (aHR 1.11, 95% CI 1.06-1.17) and so were all of its components. The risk of BC increased as the number of the components increased (aHR 1.46, 95% CI 1.26-1.61 for women with all five components). Compared to the sustained non-MetS group, the aHR (95% CI) for BC was 1.11 (1.04-1.19) in the transition to MetS group, 1.05 (0.96-1.14) in the transition to non-MetS group, and 1.18 (1.12-1.25) in the sustained MetS group.

CONCLUSIONS

Significantly increased BC risk was observed in the sustained MetS and transition to MetS groups. These findings are clinically meaningful in that efforts to recover from MetS may lead to reduced risk of BC.