Associations of clothing size, adiposity and weight change with risk of postmenopausal breast cancer in the UK Women's Cohort Study (UKWCS)

Weight-centric prevention of cancer

Background

The link between excess adiposity and carcinogenesis has been well established for multiple malignancies, and cancer is one of the main contributors to obesity-related mortality. The potential role of different weight-loss interventions on cancer risk modification has been assessed, however, its clinical implications remain to be determined. In this clinical review, we present the data assessing the effect of weight loss interventions on cancer risk.

Methods

In this clinical review, we conducted a comprehensive search of relevant literature using MEDLINE, Embase, Web of Science, and Google Scholar databases for relevant studies from inception to January 20, 2024. In this clinical review, we present systematic reviews and meta-analysis, randomized clinical trials, and prospective and retrospective observational studies that address the effect of different treatment modalities for obesity in cancer risk. In addition, we incorporate the opinions from experts in the field of obesity medicine and oncology regarding the potential of weight loss as a preventative intervention for cancer.

Results

Intentional weight loss achieved through different modalities has been associated with a reduced cancer incidence. To date, the effect of weight loss on the postmenopausal women population has been more widely studied, with multiple reports indicating a protective effect of weight loss on hormone-dependent malignancies. The effect of bariatric interventions as a protective intervention for cancer has been studied extensively, showing a significant reduction in cancer incidence and mortality, however, data for the effect of bariatric surgery on certain specific types of cancer is conflicting or limited.

Conclusion

Medical nutrition therapy, exercise, antiobesity medication, and bariatric interventions, might lead to a reduction in cancer risk through weight loss-dependent and independent factors. Further evidence is needed to better determine which population might benefit the most, and the amount of weight loss required to provide a clinically significant preventative effect.

Oxidative Stress Linking Obesity and Cancer: Is Obesity a 'Radical Trigger' to Cancer?

Obesity is on the rise worldwide, and consequently, obesity-related non-communicable diseases are as well. Nutritional overload induces metabolic adaptations in an attempt to restore the disturbed balance, and the byproducts of the mechanisms at hand include an increased generation of reactive species. Obesity-related oxidative stress causes damage to vulnerable systems and ultimately contributes to neoplastic transformation. Dysfunctional obese adipose tissue releases cytokines and induces changes in the cell microenvironment, promoting cell survival and progression of the transformed cancer cells. Other than the increased risk of cancer development, obese cancer patients experience higher mortality rates and reduced therapy efficiency as well. The fact that obesity is considered the second leading preventable cause of cancer prioritizes the research on the mechanisms connecting obesity to cancerogenesis and finding the solutions to break the link. Oxidative stress is integral at different stages of cancer development and advancement in obese patients. Hypocaloric, balanced nutrition, and structured physical activity are some tools for relieving this burden. However, the sensitivity of simultaneously treating cancer and obesity poses a challenge. Further research on the obesity-cancer liaison would offer new perspectives on prevention programs and treatment development.

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.

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.

Traditional and Novel Adiposity Indicators and Pancreatic Cancer Risk: Findings from the UK Women's Cohort Study

(1) Background: We studied the association of both conventional (BMI, waist and hip circumference and waist-hip ratio) and novel (UK clothing sizes) obesity indices with pancreatic cancer risk in the UK women's cohort study (UKWCS). (2) Methods: The UKWCS recruited 35,792 women from England, Wales and Scotland from 1995 to 1998. Cancer diagnosis and death information were obtained from the National Health Service (NHS) Central Register. Cox's proportional hazards regression was used to evaluate the association between baseline obesity indicators and pancreatic cancer risk. (3) Results: This analysis included 35,364 participants with a median follow-up of 19.3 years. During the 654,566 person-years follow up, there were 136 incident pancreatic cancer cases. After adjustments for age, smoking, education and physical activity, each centimetre increase in hip circumference (HR: 1.03, 95% CI: 1.01-1.05, p = 0.009) and each size increase in skirt size (HR: 1.12, 95% CI: 1.02-1.23, p = 0.041) at baseline increased pancreatic cancer risk. Baseline BMI became a significant predictor of pancreatic cancer risk (HR: 1.04, 95% CI: 1.00-1.08, p = 0.050) when latent pancreatic cancer cases were removed. Only baseline hip circumference was associated with pancreatic cancer risk (HR: 1.03, 95% CI: 1.00-1.05, p = 0.017) when participants with diabetes at baseline were excluded to control for reverse causality. (4) Conclusion: Hip circumference and skirt size were significant predictors of pancreatic cancer risk in the primary analysis. Thus, hip circumference is useful to assess body shape relationships. Additionally, standard skirt sizes offer an economical and objective alternative to conventional obesity indices for evaluating pancreatic cancer risk in women.

Cancer prevention through weight control-where are we in 2020?

Growing data from epidemiological studies highlight the association between excess body fat and cancer incidence, but good indicative evidence demonstrates that intentional weight loss, as well as increasing physical activity, offers much promise as a cost-effective approach for reducing the cancer burden. However, clear gaps remain in our understanding of how changes in body fat or levels of physical activity are mechanistically linked to cancer, and the magnitude of their impact on cancer risk. It is important to investigate the causal link between programmes that successfully achieve short-term modest weight loss followed by weight-loss maintenance and cancer incidence. The longer-term impact of weight loss and duration of overweight and obesity on risk reduction also need to be fully considered in trial design. These gaps in knowledge need to be urgently addressed to expedite the development and implementation of future cancer-control strategies. Comprehensive approaches to trial design, Mendelian randomisation studies and data-linkage opportunities offer real possibilities to tackle current research gaps. In this paper, we set out the case for why non-pharmacological weight-management trials are urgently needed to support cancer-risk reduction and help control the growing global burden of cancer.

Maternal pre-pregnancy body mass index, gestational weight gain and breastfeeding outcomes: a cross-sectional analysis

BACKGROUND

It is well established that mothers with above-normal pre-pregnancy BMI are at increased risk of breastfeeding cessation; however, the impact of pregnancy weight-gain (PWG) is less well-defined. Excess PWG may alter the hormonal preparation of breast tissue for lactation, increase the risk of complications that negatively impact breastfeeding (e.g. Cesarean-section, gestational diabetes), and may make effective latch more difficult to achieve.

METHODS

Our objective was to determine the impact of PWG and pre-pregnancy BMI on the risk of breastfeeding cessation utilizing the Institute of Medicine's 2009 recommendations. Cox proportional hazards models were utilized to estimate the risk of cessation of exclusive breastfeeding, and cessation of any breastfeeding among women who initiated exclusive and any breastfeeding, respectively, in a cross sectional sample of survey respondents from a New York county (N = 1207). PWG category was interacted with pre-pregnancy BMI (3 levels of pre-pregnancy BMI, 3 levels of PWG). Confounders of the relationship of interest were evaluated using directed acyclic graphs and bivariate analyses; variables not on the proposed causal pathway and associated with the exposure and outcome were included in multivariate models.

RESULTS

After adjustment, women of normal and obese pre-pregnancy BMI with greater-than-recommended PWG had 1.39 (1.03-1.86) and 1.48 (1.06-2.07) times the risk of any breastfeeding cessation within the first 3 months postpartum compared to women with normal pre-pregnancy BMI who gained within PWG recommendations. Overweight women with greater-than-recommended PWG were at increased risk of cessation, although not significantly (aHR [95% CI]: 1.29 [0.95-1.75]). No significant relationship was observed for exclusive breastfeeding cessation.

CONCLUSIONS

Pre-pregnancy BMI and PWG may be modifiable risk factors for early breastfeeding cessation. Understanding the mechanism behind this risk should be ascertained by additional studies aimed at understanding the physiological, social, logistical (positioning) and other issues that may lead to early breastfeeding cessation.

Body shape and pants size as surrogate measures of obesity among males in epidemiologic studies

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Alternative anthropometric indicators reflect overall and abdominal obesity in males.

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Abdominal obesity is predicted using age, pants size, Stunkard’s silhouette & weight.

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Stunkard’s silhouette scale reflects well body mass index recently and in the past.

This study aimed at characterizing anthropometric indicators that can be used as alternatives to measurements for assessing overall obesity over adulthood and abdominal obesity among men. We used data from a population-based case-control study of prostate cancer conducted in Montreal, Canada in 2005–2012. It included men aged ≤ 75 years, 1872 of which were newly diagnosed with prostate cancer, and 1918 others randomly selected from the electoral list. In-person interviews elicited reports of height as well as of weight, pants size and Stunkard’s silhouette at 5 time points over adulthood, i.e., for the ages of 20, 40, 50 and 60 years, if applicable, and at the time of interview. Waist and hip circumferences were measured by interviewers following a validated protocol. Analyses were conducted on the overall sample of 3790 subjects, after having confirmed that results did not differ according to disease status. Stunkard’s silhouette scale proved to be an easy-to-administer tool that reflects well reported body mass index, either recently or decades in the past among adult males. It was discriminatory enough to classify individuals according to commonly-used obesity categories. We observed that a model including age, reported pants size, silhouette and weight can reasonably predict current abdominal obesity. In conclusion, alternative anthropometric indicators can serve as valuable means to assess overall and abdominal obesity when measurements cannot be envisaged in the context of epidemiological studies.

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.