Weight change and risk of endometrial cancer

Approaches to prevention of gynecological malignancies

Gynecological malignancies represent one of the prevalent diseases in the female sex and prevention is essential to limit their incidence and mortality. Nowadays, not all malignancies benefit from adequate screening methods for this reason new biomarkers and methods are being developed to undertake timely and effective therapies.

Association between weight cycling and risk of colorectal cancer: a prospective cohort study

BACKGROUND

Weight cycling is the repeated episodes manifesting intentional weight loss and subsequent unintentional weight gain. Whether the frequency and magnitude of weight cycling is associated with colorectal cancer risk independent of body mass index (BMI) remains unknown.

METHODS

Two prospective cohort studies, Nurses' Health Study I and Health Professionals Follow-up Study, followed 85,562 participants from 1992 to 2014. Participants completed a questionnaire regarding the frequency and magnitude of intentional weight loss in the past 4 years at the baseline. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox proportional hazard model.

RESULTS

We identified 1626 colorectal cancer cases during up to 22 years of follow-up. In the pooled analysis of HPFS and NHS, compared to non-weight cycling, moderate weight cycling (≥3 times of intentional weight loss of ≥2.3-4.4 kg) was associated with a reduced risk of colorectal cancer after adjustment for confounders, including attained BMI after weight cycling (HR = 0.82, 95% CI 0.69, 0.97). However, no significant association was observed in mild weight cyclers and in severe weight cyclers.

CONCLUSIONS

Moderate weight cycling was associated with a lower risk of colorectal cancer independent of BMI. This finding needs further studies for replication and putative biological mechanisms.

Reproductive Factors and Endometrial Cancer Risk Among Women

Importance

Despite evidence of an association between reproductive factors and endometrial cancer risk, prospective studies have been conducted mainly in non-Asian countries.

Objective

To assess the association between reproductive factors, such as number of deliveries, age at menarche, or menopause, and endometrial cancer risk.

Design, Setting, and Participants

This cohort study used pooled individual data from 13 prospective cohort studies conducted between 1963 and 2014 in the Asia Cohort Consortium. Participants were Asian women. Data analysis was conducted from September 2019 to April 2023.

Exposures

Reproductive factors were assessed using a questionnaire in each cohort.

Main Outcomes and Measures

The main outcome was time to incidence of endometrial cancer. A Cox proportional hazards model was used to calculate hazard ratios (HRs) and 95% CIs.

Results

A total of 1005 endometrial cancer cases were detected among 332 625 women (mean [SD] age, 54.3 [10.4] years) during a mean (SD) of 16.5 (6.4) years of follow-up. Increasing number of deliveries was associated with a decreased endometrial cancer risk in a dose-response manner (≥5 deliveries vs nulliparous [reference]: HR, 0.37; 95% CI, 0.26-0.53; P for trend < .001). Compared with menarche at younger than 13 years, menarche at 17 years or older had an HR of 0.64 (95% CI, 0.48-0.86; P for trend < .001). Late menopause (age ≥55 years) showed an HR of 2.84 (95% CI, 1.78-4.55; P for trend < .001) compared with the youngest age category for menopause (<45 years). Age at first delivery, hormone therapy, and breastfeeding were not associated with endometrial cancer risk.

Conclusions and Relevance

This large pooled study of individual participant data found that late menarche, early menopause, and a higher number of deliveries were significantly associated with a lower risk of endometrial cancer. These convincing results from Asian prospective studies add to the growing body of evidence for the association between reproductive factors and endometrial cancer.

Does weight loss in women with obesity induce regression of endometrial hyperplasia? A systematic review

Obesity is a leading risk factor for endometrial cancer and its precursor, endometrial hyperplasia (EH). Currently, weight loss is recommended for people with EH and obesity, but evidence to guide weight management as primary or adjunctive therapy is limited. This systematic review aims to assess the role of weight loss in inducing histopathological regression of EH in women with obesity. A systematic search of Medline, PubMed, Embase and The Cochrane Library databases was conducted in January 2022. Studies reporting on participants with EH who underwent weight loss interventions, incorporating comparisons of pre- and post-intervention histology, were included. Studies were limited to those published in English with full text available. Six studies met the inclusion criteria, all of which reported outcomes after bariatric surgery. Three studies reported outcomes for the same group of participants, therefore only one outcome set was included. Pre-operative endometrial biopsy results were available for 167 women, and 81 had post-operative biopsies reported. Nineteen women (11.4% of those biopsied) had EH pre-operatively; 17 underwent repeat sampling post-operatively. Twelve (71%) had complete histological resolution, 1 (6%) had partial regression from complex hyperplasia to simple hyperplasia, 1 (6%) had persistent atypical hyperplasia, and 3 (18%) had persistent simple hyperplasia. One patient with a normal pre-intervention biopsy had simple hyperplasia post-operatively. Due to poor quality and overall scarcity of data, the role of weight loss in the primary or adjunctive treatment of EH is unknown. Future studies should prospectively assess weight loss modalities and targets, as well as use of concurrent therapies.

MyLynch: A Patient-Facing Clinical Decision Support Tool for Genetically-Guided Personalized Medicine in Lynch Syndrome

Lynch syndrome (LS) is a hereditary cancer susceptibility condition associated with varying cancer risks depending on which of the five causative genes harbors a pathogenic variant; however, lifestyle and medical interventions provide options to lower those risks. We developed MyLynch, a patient-facing clinical decision support (CDS) web application that applies genetically-guided personalized medicine (GPM) for individuals with LS. The tool was developed in R Shiny through a patient-focused iterative design process. The knowledge base used to estimate patient-specific risk leveraged a rigorously curated literature review. MyLynch informs LS patients of their personal cancer risks, educates patients on relevant interventions, and provides patients with adjusted risk estimates, depending on the interventions they choose to pursue. MyLynch can improve risk communication between patients and providers while also encouraging communication among relatives with the goal of increasing cascade testing. As genetic panel testing becomes more widely available, GPM will play an increasingly important role in patient care, and CDS tools offer patients and providers tailored information to inform decision-making. MyLynch provides personalized cancer risk estimates and interventions to lower these risks for patients with LS.

Weight Cycling in Women: Adaptation or Risk?

Obesity, dieting, and weight cycling are common among reproductive-age women. Weight cycling refers to intentional weight loss followed by unintentional weight regain. Weight loss is accompanied by changes in gut peptides, adipose hormones, and energy expenditure that promote weight regain to a tightly regulated set point. While weight loss can improve body composition and surrogate markers of cardiometabolic health, it is hypothesized that the weight regain can result in an overshoot effect, resulting in excess weight gain, altered body composition, and negative effects on surrogate markers of cardiometabolic health. Numerous observational studies have examined the association of weight cycling and health outcomes. There appears to be modest association between weight cycling with type 2 diabetes mellitus and dyslipidemia in women, but no association with hypertension, cardiovascular events, and overall cancer risk. Interestingly, mild weight cycling may be associated with a decreased risk of overall and cardiovascular mortality. Little is known about the effects of weight cycling in the preconception period. Although obesity and weight gain are associated with pregnancy complications, preconception weight loss does not appear to mitigate the risk of most pregnancy complications related to obesity. Research on preconception weight cycling may provide insight into this paradox.

Reprogramming of Fatty Acid Metabolism in Gynaecological Cancers: Is There a Role for Oestradiol?

Gynaecological cancers are among the leading causes of cancer-related death among women worldwide. Cancer cells undergo metabolic reprogramming to sustain the production of energy and macromolecules required for cell growth, division and survival. Emerging evidence has provided significant insights into the integral role of fatty acids on tumourigenesis, but the metabolic role of high endogenous oestrogen levels and increased gynaecological cancer risks, notably in obesity, is less understood. This is becoming a renewed research interest, given the recently established association between obesity and incidence of many gynaecological cancers, including breast, ovarian, cervical and endometrial cancers. This review article, hence, comprehensively discusses how FA metabolism is altered in these gynaecological cancers, highlighting the emerging role of oestradiol on the actions of key regulatory enzymes of lipid metabolism, either directly through its classical ER pathways, or indirectly via the IGIFR pathway. Given the dramatic rise in obesity and parallel increase in the prevalence of gynaecological cancers among premenopausal women, further clarifications of the complex mechanisms underpinning gynaecological cancers are needed to inform future prevention efforts. Hence, in our review, we also highlight opportunities where metabolic dependencies can be exploited as viable therapeutic targets for these hormone-responsive cancers.

Spatiotemporal trends in burden of uterine cancer and its attribution to body mass index in 204 countries and territories from 1990 to 2019

BACKGROUND

Uterine cancer is one of the most common female cancers worldwide, with huge heterogeneity in morbidity and mortality. Although a high body-mass index (BMI) has been linked to uterine cancer, systematic reports about the influence of high BMI and its temporal trends are scarce.

METHODS

The annual morbidity, mortality, and disability-adjusted life years (DALYs) of uterine cancer in 204 countries or territories were retrieved from the GBD 2019 study. To reflect trends in disease burden, we also calculated the estimated annual percentage change (EAPC) based on the age-standardized rates of uterine cancer from 1990 to 2019.

RESULTS

The global incident cases of uterine cancer increased 2.3 times from 187,190 in 1990 to 435,040 in 2019. Although the age-standardized incidence rate (ASIR) of uterine cancer increased worldwide from 8.67/100,000 in 1990 to 9.99/100,000 in 2019, the age-standardized death rate (ASDR) and DALY rate decreased during the same period. High socio-demographic index (SDI) countries tended to have a higher ASIR than developing regions, and their increasing trend in ASIR was also more pronounced. The disease was rare before 40 years old, but its risk rose sharply among women aged 50-70. A high BMI was linked to more than one-third of deaths from uterine cancer in 2019.

CONCLUSIONS

The incidence in developed areas was significantly higher than in developing areas and also increased much more rapidly. Elderly females, especially those with a high BMI, have a higher risk of uterine cancer. Therefore, more health resources may be needed to curb the rising burden in specific populations.

Adult lifetime body mass index trajectories and endometrial cancer risk

OBJECTIVE

To identify body mass index (BMI) trajectories in adult life and to examine their association with endometrial cancer (EC) risk, also exploring whether relations differ by HRT use.

DESIGN

Pooled analysis of two case control studies.

SETTING

Italy and Switzerland.

POPULATION

A total of 458 EC cases and 782 controls.

METHODS

We performed a latent class growth model in order to identify homogenous BMI trajectories over 6 decades of age, with a polynomial function of age. Odds Ratios (ORs) and the corresponding 95% confidence intervals (CI) for EC risk were derived through a multiple logistic regression model, correcting for classification error.

MAIN OUTCOME MEASURES

The relation of BMI trajectories with endometrial cancer.

RESULTS

We identified 5 BMI trajectories. Compared with women in the 'Normal weight-stable' trajectory, a reduction by about 50% in the risk of EC emerged for those in the 'Underweight increasing to normal weight' (95% CI=0.28-0.99). The 'Normal weight increasing to overweight' and the 'Overweight-stable' trajectories were associated to, respectively, an excess of 3% (95% CI=0.66-1.60) and of 71% (95% CI= 1.12-2.59) in cancer risk. The OR associated to the trajectory 'Overweight increasing to obese' was 2.03 (95% CI= 1.31-3.13). Stronger effects emerged among HRT never users (OR= 2.19 for the 'Overweight-stable' trajectory and OR=2.49 for the 'Overweight increasing to obese' trajectory).

CONCLUSIONS

Our study suggests that longer exposure to overweight and obesity across lifetime is associated with an increased risk of endometrial cancer. Weight during adulthood also appears to play an important role.

Effectiveness of profile by Sanford behavioral weight loss program for weight loss following endometrial cancer treatment

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Patients lost greater body weight (15.3%) over 12 months with a behavioral weight management program vs. standard care (2.3%).

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Health coach utilization was high with patients averaging 28.3 health coaching appointments over 12 months.

•

This behavioral weight management program should be evaluated for reducing risk of endometrial cancer recurrence.

Objective

To examine differences in weight change and Body Mass Index (BMI) at 12 months among women in remission from endometrial cancer who enrolled in a behavioral weight loss (BWL) program and a matched patient control group.

Methods

Women (n = 22) were enrolled into the BWL program and were compared against a control group (n = 28) that accounted for age, BMI, cancer type, cancer stage, and treatment dates. The BWL program included weekly health coaching meetings that targeted nutrition, activity, and behavior change topics.

Results

Women enrolled in the BWL program completed 28.3 ± 14.1 appointments over 12 months resulting in an average weight change of −14.2 ± 7.8 kg (−13.3 ± 7.4%) at 6 months and −16.4 ± 12.5 kg (−15.3 ± 11.4%) at 12 months (all p < 0.001). Women in the control group had a weight change of −1.7 ± 8.4 kg (−2.3 ± 7.6%) at 12 months which was significantly different than the BWL condition (p < 0.001). BMI was significantly reduced in the BWL group at 6 months (−4.8 ± 4.5, p < 0.001) and 12 months (−5.2 ± 5.9, p < 0.001) and significantly different than in the control group at 12 months (−0.9 ± 3.2, p = 0.007).

Conclusions

The BWL program yielded clinically significant weight loss for endometrial cancer survivors. Future work should include longer follow up periods and include additional behavioral and psychosocial outcomes.

Body weight variability and cancer incidence in men aged 40 years and older-Korean National Insurance Service Cohort

Repeated weight fluctuation has been proposed as a potential risk factor for increasing morbidity and mortality including cancer. We aimed to investigate the association between body weight variability (BWV) and all cancer and site-specific cancer incidence and the impact of smoking on these associations. A total of 1,759,848 cancer-free male subjects who had their weight measured at least 5 times from the National Health Insurance Service-Health Screening Cohort from 2002 to 2011 were included and followed up until 2015. BWV was defined as the average absolute difference between successive values (ASV). The risk of cancer and site-specific cancer from BWV was identified using Cox proportional hazards regression analysis using hazard ratios (HRs) and 95% confidence intervals (CIs) adjusted for potential confounders including weight, and stratified analysis was also conducted according to smoking status. During the 7,015,413 person-years of follow-up, 11,494 patients (0.65%) developed new-onset cancers. BWV was associated with a higher risk of all cancers after adjustment for confounders. The highest BWV quintile group compared to the lowest had greater risks of all cancers and site-specific cancers including lung, liver, and prostate cancer (HR 1.22, 95% CI 1.15–1.30; HR 1.22, 95% CI 1.07–1.39; HR 1.46, 95% CI 1.19–1.81; HR 1.36, 95% CI 1.15–1.62, in all cancers, lung, liver and prostate cancer, respectively). Due to small number of cancer occurrence, the risk of kidney cancer was increased, but statistically insignificant (HR 1.38, 95% CI 0.91–2.10). Similar results were observed in noncurrent smokers. However, in current smokers, the risks of all cancers and only prostate cancer were significantly increased in the highest BWV quintile group (HR 1.19, 95% CI 1.09–1.31; HR 1.51, 95% CI 1.08–2.11). The risk of kidney cancer also increased in this group, although the finding was not statistically significant (HR 1.77, 95% CI 0.87–3.63) This study suggested BWV is an independent risk factor for cancer in men, especially in lung, liver, and prostate cancer, but evidence was weaker in kidney cancer. This association remained significant only in prostate cancer in current smokers.

Association between weight cycling and risk of kidney cancer: a prospective cohort study and meta-analysis of observational studies

PURPOSE

Weight cycling is common in populations. However, it is unclear whether frequency and magnitude of weight cycling is associated with kidney cancer risk, independent of body mass index (BMI).

METHODS

A prospective cohort study followed 85,562 participants from Health Professionals Follow-up Study and Nurses' Health Study (1992-2014). At baseline, participants reported frequency and magnitude of intentional weight loss in the past 4 years. Cox proportional hazard model was used to estimate hazard ratios (HR) and 95% confidence intervals (CI). We also conducted a meta-analysis of all available observational studies including our two cohorts.

RESULTS

During 22 years of follow-up, we identified 441 kidney cancer cases. Compared with non-weight cyclers (no attempt of intentional weight loss), severe cyclers (≥ 3 times of intentional weight loss of ≥ 4.5 kg) were at increased kidney cancer risk after adjusting for BMI before weight cycling (pooled multivariable-adjusted HR, 1.78; 95% CI, 1.19, 2.66). Additional adjustment for attained BMI after weight cycling had minimal influence. There was a positive trend between weight cycling by frequency and magnitude and kidney cancer risk (P-trend = 0.01). Moreover, the observed positive association did not differ by subtypes of cyclers (e.g., adiposity status, weight-loss methods). In the meta-analysis, we found a strong positive association between weight cycling and kidney cancer risk (summary relative risk for weight cyclers vs. non-cyclers, 1.51; 95% CI, 1.16, 1.96; I²: 52.2%; 6 studies).

CONCLUSION

Frequent substantial weight cycling was associated with increased risk of kidney cancer, independent of BMI. Our study suggests that weight cycling may be an important risk factor for kidney cancer.

The levonorgestrel intrauterine system for prevention of endometrial cancer in women with obesity: A cost-effectiveness study

OBJECTIVE

To estimate the cost-effectiveness of the levonorgestrel intrauterine system (LNG-IUS) as an endometrial cancer prevention strategy in women with obesity.

METHODS

A Markov decision-analytic model was used to compare 5 strategies in women with a body mass index of 30 or greater: 1) Usual care 2) LNG-IUS for 5 years 3) LNG-IUS for 7 years 4) LNG-IUS for 5 years, replaced once for a total of 10 years 5) LNG-IUS for 7 years, replaced once for a total of 14 years. Obesity was presumed to be associated with a 3-fold relative risk of endometrial cancer incidence and a 2.65-fold disease-specific mortality. The LNG-IUS was assumed to confer a 50% reduction in cancer incidence over the period of the LNG-IUS insertion. Outcomes were incremental cost-effectiveness ratios, calculated in 2019 Canadian dollars (CAD) per year of life saved. One-way and two-way sensitivity analyses were performed.

RESULTS

The LNG-IUS strategy was considered cost-effective if the cost of the intervention is less than $66,400 CAD ($50,000 US dollars) per year of life saved. The strategy becomes cost-effective if the LNG-IUS is inserted at age 57 (strategy #2), at age 52 for strategy #3, at age 51 for strategy #4 and at age 45 for strategy #5, when compared to usual care. The results are stable to variations in cost but sensitive to the estimated risk reduction of the LNG-IUS and the impact of obesity on endometrial cancer incidence and disease-specific mortality.

CONCLUSION

The LNG-IUS is a cost-effective method of endometrial cancer prevention in women with obesity.

Weight fluctuation and risk of hepatocellular carcinoma: a nationwide population-based 8-million-subject study

BACKGROUND/AIM

The importance of hepatocellular carcinoma (HCC) caused by obesity has been emphasized. Many studies have shown that weight fluctuations as well as high BMI are associated with various adverse outcomes. In this study, we investigated the relationship between weight fluctuation and HCC in general populations drawn from a nationwide population-based cohort.

METHOD

A population-based cohort study including 8,001,829 subjects participating in more than three health examinations within 5 years from the index year were followed until the end of 2017. The degree of weight fluctuation and incidence of HCC during the period were evaluated.

RESULTS

When we classified groups according to baseline body mass index (BMI) level, the highest risk for HCC was observed in subjects with BMI of 30 or greater (adjusted hazard ratio [aHR] 1.40, 95% confidence interval [CI] 1.27-1.54). Also, increasing trends for the relationship between weight fluctuation and HCC were observed in multivariable Cox proportional analyses. The risk of HCC increased by 16% (aHR 1.16, 95% CI 1.12-1.20) for the highest quartile of weight fluctuation relative to the lowest quartile. These findings were consistent regardless of the baseline BMI or other metabolic factors. However, these effects of weight fluctuation on HCC were not observed in liver cirrhosis or viral hepatitis subgroups.

CONCLUSION

Weight fluctuation is an independent predictor of HCC. In the absence of liver cirrhosis or chronic hepatitis, the impact of weight fluctuation on HCC is further emphasized. These results suggest maintaining steady weight is recommended to reduce the risk of HCC.

Improving response to progestin treatment of low-grade endometrial cancer

OBJECTIVES

This review examines how response rates to progestin treatment of low-grade endometrial cancer can be improved. In addition to providing a brief overview of the pathogenesis of low-grade endometrial cancer, we discuss limitations in the current classification of endometrial cancer and how stratification may be refined using molecular markers to reproducibly identify 'low-risk' cancers which may represent the best candidates for progestin therapy. We also discuss constraints in current approaches to progestin treatment of low-grade endometrial cancer and perform a systematic review of predictive biomarkers.

METHODS

PubMed, ClinicalTrials.gov, and Cochrane Library were searched for studies reporting pre-treatment biomarkers associated with outcome in women with low-grade endometrial cancer or endometrial hyperplasia with an intact uterus who received progestin treatment. Studies of fewer than 50 women were excluded. The study protocol was registered in PROSPERO (ID 152374). A descriptive synthesis of pre-treatment predictive biomarkers reported in the included studies was conducted.

RESULTS

Of 1908 records reviewed, 19 studies were included. Clinical features such as age or body mass index cannot predict progestin response. Lesions defined as 'low-risk' by FIGO criteria (stage 1A, grade 1) can respond well; however, the reproducibility and prognostic ability of the current histopathological classification system is suboptimal. Molecular markers can be reproducibly assessed, have been validated as prognostic biomarkers, and may inform patient selection for progestin treatment. DNA polymerase epsilon (POLE)-ultramutated tumors and a subset of p53 wild-type or DNA mismatch repair (MMR)-deficient tumors with 'low-risk' features (eg, progesterone and estrogen receptor-positive) may have improved response rates, though this needs to be validated.

DISCUSSION

Molecular markers can identify cases which may be candidates for progestin treatment. More work is needed to validate these biomarkers and potentially identify new ones. Predictive biomarkers are anticipated to inform future research into progestin treatment of low-grade endometrial cancer and ultimately improve patient outcomes.

Endometrial cancer prevention in high-risk women

Endometrial cancer (EC) is the most common gynaecological malignancy, and its incidence is rising alongside the growing prevalence of obesity. Effective risk-reducing interventions hijacking the key mechanisms driving endometrial carcinogenesis may affect EC diagnoses if aimed at those at greatest risk. An understanding of the key risk factors and their role in tumourigenesis is critical in developing such prevention strategies. In this review, we summarise the major risk factors for EC and the evidence for available risk-reducing interventions in high-risk women. We suggest potential prevention strategies and make a case for the need for risk prediction models that identify specific groups of women at a particularly high risk of EC for whom risk-reducing interventions are likely to have a significant impact.

Intentional weight loss, weight cycling, and endometrial cancer risk: a systematic review and meta-analysis

PURPOSE

Weight cycling, defined as intentional weight loss followed by unintentional weight regain, may attenuate the benefit of intentional weight loss on endometrial cancer risk. We summarized the literature on intentional weight loss, weight cycling after intentional weight loss, bariatric surgery, and endometrial cancer risk.

METHODS

A systematic search was conducted using MEDLINE, Embase, and Cochrane Central Register of Controlled Trials databases published between January 2000 and November 2018. We followed Preferred Reporting Items of Systematic Reviews and Meta-analysis (PRISMA) guidelines. We qualitatively summarized studies related to intentional weight loss and weight cycling due to the inconsistent definition, and quantitatively summarized studies when bariatric surgery was the mechanism of intentional weight loss.

RESULTS

A total of 127 full-text articles were reviewed, and 13 were included (bariatric surgery n=7, self-reported intentional weight loss n=2, self-reported weight cycling n=4). Qualitative synthesis suggested that, compared with stable weight, self-reported intentional weight loss was associated with lower endometrial cancer risk (RR range 0.61-0.96), whereas self-reported weight cycling was associated with higher endometrial cancer risk (OR range 1.07-2.33). The meta-analysis yielded a 59% lower risk of endometrial cancer following bariatric surgery (OR 0.41, 95% CI 0.22 to 0.74).

CONCLUSIONS

Our findings support the notion that intentional weight loss and maintenance of a stable, healthy weight can lower endometrial cancer risk. Strategies to improve awareness and maintenance of weight loss among women with obesity are needed to reduce endometrial cancer risk.

Intentional Weight Loss and Obesity-Related Cancer Risk

Background

Epidemiologic studies regarding weight loss and subsequent cancer risk are sparse. The study aim was to evaluate the association between weight change by intentionality and obesity-related cancer incidence in the Women’s Health Initiative Observational Study. Eleven cancers were considered obesity related: breast, ovary, endometrium, colon and rectum, esophagus, kidney, liver, multiple myeloma, pancreas, stomach, and thyroid.

Methods

Postmenopausal women (n = 58 667) aged 50–79 years had body weight and waist circumference (WC) measured at baseline and year 3. Weight or WC change was categorized as stable (change < ±5%), loss (≥5%), and gain (≥5%). Self-report at year 3 characterized weight loss as intentional or unintentional. During the subsequent 12 years (mean) of follow-up, 6033 incident obesity-related cancers were identified. Relationships were evaluated using multivariable Cox proportional hazards regression models.

Results

Compared to women with stable weight, women with intentional weight loss had lower obesity-related cancer risk (hazard ratio [HR] = 0.88, 95% confidence interval [CI] = 0.80 to 0.98). A similar result was observed for intentional WC reduction (HR = 0.88, 95% CI = 0.80 to 0.96). Among all cancers, intentional weight loss was most strongly associated with endometrial cancer (HR = 0.61, 95% CI = 0.42 to 0.88). Intentional WC loss was also associated with lower colorectal cancer risk (HR = 0.79, 95% CI = 0.63 to 0.99). Unintentional weight loss or weight gain was not associated with overall obesity-related cancer risk.

Conclusion

Intentional weight or WC loss in postmenopausal women was associated with lower risk of obesity-related cancer. These findings suggest that postmenopausal women who intentionally lose weight can reduce their obesity-related cancer risk.

Age at Menopause and Risk of Developing Endometrial Cancer: A Meta-Analysis

Object

The association of age at menopause with endometrial cancer remains controversial. Therefore, we quantitatively summarized the evidence from observational studies with a meta-analysis.

Methods

We searched PubMed, Web of Science, Embase, Medline, Chinese National Knowledge Infrastructure (CNKI), and Wan Fang Med online up to March 2019, and all eligible case-control and cohort studies were included in the study. Pooled relative risks (RRs) with 95% confidence intervals (CIs) were calculated using the random-effects model. The dose-response relationship was assessed by restricted cubic spline model. The heterogeneity among studies was evaluated by I². Metaregression was used to explore the potential sources of between-study heterogeneity. Egger's test was used to estimate publication bias.

Results

Eighteen articles including 957242 subjects with 4781 cases were included in the meta-analysis. The pooled RR (95%CI) of endometrial cancer for the highest versus the lowest age at menopause was 1.89 (95%CI: 1.58-2.26). For dose-response analysis, a nonlinear relationship was found between age at menopause and endometrial cancer, and the positive association became statistically significant when age at menopause was greater than 46.5 years old.

Conclusions

This meta-analysis suggested that age at menopause was positively associated with endometrial cancer. For women whose menopausal age over 46.5 years old, the risk of endometrial cancer increased with the age at menopause.

Association of abnormal glucose metabolism and insulin resistance in patients with atypical and typical endometrial cancer

This study aimed to detect glucose metabolism indicators and insulin resistance index in patients with endometrial cancer, and to explore the clinical significance and correlation between them. A total of 65 patients with endometrial cancer (52 of typical endometrial and 13 cases of atypical endometrial cancer patients, 27 with diabetes mellitus, and 38 cases without diabetes mellitus) were selected at the People's Hospital of Rizhao from June, 2010 to June, 2016 to serve as the observation group. During the same period, 62 patients with endometrial benign lesions (24 with diabetes mellitus and 38 cases without diabetes mellitus) were selected as the control group. General information including height, body weight, body mass index (BMI), abdominal, waist and hip circumference, and waist-to-hip ratio (WHR) was compared between the two groups. Fasting blood glucose, glycosylated hemoglobin, fasting insulin level (FINS), insulin resistance index (HOMA-IR), follicle estrogen (FSH), luteinizing hormone and estradiol (estrogen) were detected and compared between the two groups. Multivariate logistic regression was used to analyze the risk factors for endometrial cancer. The results showed that there were no significant differences in the height and hip circumference among the typical, atypical and control groups. By contrast, weight, BMI, waist circumference, abdominal circumference and the WHR of the typical group were significantly higher than those of the atypical and control groups (P<0.05). No significant differences were found between the atypical and control groups (P>0.05). Levels of the FINS and HOMA-IR typical group were significantly higher than those in the atypical and control groups, and the incidence of hyperinsulinemia and insulin resistance was significantly higher in the observation than in the control group (P<0.05). Of the patients with diabetes, the levels of FINS, HOMA-IR and estrogen were significantly higher, but the level of FSH was significantly lower in the observation compared to the control group (P<0.05). For patients without diabetes, significant differences in the levels of FINS and HOMA-IR were found between the observation and control groups (P<0.05). There was no significant difference in the levels of FINS and HOMA-IR among endometrial cancer patients with different pathological features (P>0.05). HOMA-IR (OR=1.240), estrogen (OR=1.192) and FSH (OR=1.002) are risk factors for endometrial cancer. The results suggest that hyperinsulinemia and insulin resistance are risk factors of endometrial cancer. Insulin may therefore be involved in the development of endometrial cancer by affecting the level of sex hormones.

Weight Fluctuation and Cancer Risk in Postmenopausal Women: The Women's Health Initiative

Background: Weight cycling, defined by an intentional weight loss and subsequent regain, commonly occurs in overweight and obese women and is associated with some negative health outcomes. We examined the role of various weight-change patterns during early to mid-adulthood and associated risk of highly prevalent, obesity-related cancers (breast, endometrial, and colorectal) in postmenopausal women.Methods: A total of 80,943 postmenopausal women (age, 63.4 ± 7.4 years) in the Women's Health Initiative Observational Study were categorized by self-reported weight change (weight stable; weight gain; lost weight; weight cycled [1-3, 4-6, 7-10, >10 times]) during early to mid-adulthood (18-50 years). Three site-specific associations were investigated using Cox proportional hazard models [age, race/ethnicity, income, education, smoking, alcohol, physical activity, hormone therapy, diet, and body mass index (BMI)].Results: A total of 7,464 (breast = 5,564; endometrial = 788; and colorectal = 1,290) incident cancer cases were identified between September 1994 and August 2014. Compared with weight stability, weight gain was significantly associated with risk of breast cancer [hazard ratio (HR), 1.11; 1.03-1.20] after adjustment for BMI. Similarly, weight cycling was significantly associated with risk of endometrial cancer (HR = 1.23; 1.01-1.49). Weight cycling "4 to 6 times" was most consistently associated with cancer risk, showing a 38% increased risk for endometrial cancer [95% confidence interval (CI), 1.08-1.76] compared with weight stable women.Conclusions: Weight gain and weight cycling were positively associated with risk of breast and endometrial cancer, respectively.Impact: These data suggest weight cycling and weight gain increase risk of prevalent cancers in postmenopausal women. Adopting ideal body-weight maintenance practices before and after weight loss should be encouraged to reduce risk of incident breast and endometrial cancers. Cancer Epidemiol Biomarkers Prev; 26(5); 779-86. ©2017 AACR.

BGCS uterine cancer guidelines: Recommendations for practice

The British Gynaecological Cancer Society has issued the first Endometrial (Uterine) Cancer guidelines as recommendation for practice for the UK.

Intentional Weight Loss and Endometrial Cancer Risk

Purpose Although obesity is an established endometrial cancer risk factor, information about the influence of weight loss on endometrial cancer risk in postmenopausal women is limited. Therefore, we evaluated associations among weight change by intentionality with endometrial cancer in the Women's Health Initiative (WHI) observational study. Patients and Methods Postmenopausal women (N = 36,794) ages 50 to 79 years at WHI enrollment had their body weights measured and body mass indices calculated at baseline and at year 3. Weight change during that period was categorized as follows: stable (change within ± 5%), loss (change ≥ 5%), and gain (change ≥ 5%). Weight loss intentionality was assessed via self-report at year 3; change was characterized as intentional or unintentional. During the subsequent 11.4 years (mean) of follow-up, 566 incident endometrial cancer occurrences were confirmed by medical record review. Multivariable Cox proportional hazards regression models were used to evaluate relationships (hazard ratios [HRs] and 95% CIs) between weight change and endometrial cancer incidence. Results In multivariable analyses, compared with women who had stable weight (± 5%), women with weight loss had a significantly lower endometrial cancer risk (HR, 0.71; 95% CI, 0.54 to 0.95). The association was strongest among obese women with intentional weight loss (HR, 0.44; 95% CI, 0.25 to 0.78). Weight gain (≥ 10 pounds) was associated with a higher endometrial cancer risk than was stable weight, especially among women who had never used hormones. Conclusion Intentional weight loss in postmenopausal women is associated with a lower endometrial cancer risk, especially among women with obesity. These findings should motivate programs for weight loss in obese postmenopausal women.

Prospective cohort study of general and central obesity, weight change trajectory and risk of major cancers among Chinese women

General obesity, typically measured using body mass index (BMI), has been associated with an increased risk of several cancers. However, few prospective studies have been conducted in Asian populations. Although central obesity, often measured using waist-hip ratio (WHR), is more predictive for type 2 diabetes and cardiovascular diseases (CVD) risk than BMI, knowledge of its association with cancer incidence is limited. In a cohort of 68,253 eligible Chinese women, we prospectively investigated the association of BMI, WHR and weight change during adulthood with risk of overall cancer and major site-specific cancers using multivariate Cox proportional hazard models. Compared to the BMI group of 18.5-22.9 kg/m(2) , obese (BMI ≥ 30 kg/m(2) ) women were at an increased risk of developing overall cancer (hazard ratio = 1.36, 95% confidence interval = 1.21-1.52), postmenopausal breast cancer (HR: 2.43, 95% CI: 1.73-3.40), endometrial cancer (HR: 5.34, 95% CI: 3.48-8.18), liver cancer (HR: 1.93, 95% CI: 1.14-3.27) and epithelial ovarian cancer (HR: 2.44, 95% CI: 1.37-4.35). Weight gain during adulthood (per 5 kg gain) was associated with increased risk of all cancers combined (HR: 1.05, 95% CI: 1.03-1.08), postmenopausal breast cancer (HR: 1.17, 95% CI: 1.10-1.24) and endometrial cancer (HR: 1.37, 95% CI: 1.27-1.48). On the other hand, WHR was not associated with cancer risk after adjustment for baseline BMI. These findings suggest that obesity may be associated with cancer risk through different mechanisms from those for type 2 diabetes and CVD and support measures of maintaining health body weight to reduce cancer risk in Chinese women.

Body Size, Metabolic Factors, and Risk of Endometrial Cancer in Black Women

Total and abdominal obesity, as well as metabolic factors such as type 2 diabetes, have been associated with a higher risk of endometrial cancer in white women. It remains unclear to what extent these factors influence the risk of endometrial cancer in black women. We followed 47,557 participants from the Black Women's Health Study for incident endometrial cancer from 1995 through 2013 (n = 274). We used Cox regression models to estimate incidence rate ratios and 95% confidence intervals while accounting for potential confounders. Incidence rate ratios for body mass indices (weight (kg)/height (m)(2)) of 25.0-29.9, 30.0-34.9, 35.0-39.9, and ≥40.0 versus those <25.0 were 1.00 (95% confidence interval (CI): 0.67, 1.48), 1.49 (95% CI: 0.97, 2.30), 2.16 (95% CI: 1.34, 3.49), and 3.60 (95% CI: 2.24, 5.78), respectively (Ptrend <0.0001). A high weight-to-height ratio was also associated with a higher risk (for the highest quartile vs. the lowest, incidence rate ratio = 2.83, 95% CI: 1.77, 4.53), as was type 2 diabetes mellitus (incidence rate ratio = 1.52, 95% CI: 1.04, 2.21). Positive associations with measures of central adiposity (waist circumference, waist-to-hip ratio, and waist-to-height ratio) and hypertension were attenuated after we controlled for body mass index. Total adiposity was an independent risk factor for endometrial cancer among black women and appeared to explain most of the associations seen with other adiposity measures and metabolic factors.

Obesity and Endometrial Cancer

Endometrial cancer is the sixth most common cancer in women worldwide and the most common gynecologic malignancy in the developed world. This chapter explores the current epidemiologic evidence on the association between obesity and endometrial cancer risk and mortality. Using body mass index (BMI) as a measure of obesity, we found that obesity (defined as BMI > 30 and < 35 kg/m²) was associated with a 2.6-fold increase in endometrial cancer risk, while severe obesity (BMI > 35 kg/m²) was associated with a 4.7-fold increase compared to normal-weight women (BMI < 25 kg/m²). Increased central adiposity also increased endometrial cancer risk by 1.5- to twofold. Among both healthy and endometrial cancer patient populations, obesity was associated with a roughly twofold increase in endometrial cancer-specific mortality. This risk reduction was also observed for obesity and all-cause mortality among endometrial cancer patients. In the few studies that assessed risk associated with weight change, an increased endometrial cancer risk with weight gain and weight cycling was observed, whereas some evidence for a protective effect of weight loss was found. Furthermore, early-life obesity was associated with a moderately increased risk of endometrial cancer later in life. There are several mechanisms whereby obesity is hypothesized to increase endometrial cancer risk, including increased endogenous sex steroid hormones, insulin resistance, chronic inflammation and adipokines. Further research should focus on histological subtypes or molecular phenotypes of endometrial tumors and population subgroups that could be at an increased risk of obesity-associated endometrial cancer. Additionally, studies on weight gain, loss or cycling and weight loss interventions can provide mechanistic insight into the obesity-endometrial cancer association. Sufficient evidence exists to recommend avoiding obesity to reduce endometrial cancer risk.

Methylation of tumor suppressor gene CDH13 and SHP1 promoters and their epigenetic regulation by the UHRF1/PRMT5 complex in endometrial carcinoma

OBJECTIVE

Epigenetic changes in cancer and precancerous lesions could be utilized as biomarkers for cancer early detection. This study aims to investigate the novel biomarkers in endometrial carcinoma, and explore their epigenetic regulation.

METHODS

Methylation of six tumor suppressor genes (CDH13, SHP1, HIN1, DKK3, CTNNA1 and PCDH8) was evaluated in 155 endometrium samples. Changes of methylation and mRNA expression after treatment with 5-Aza-2'-deoxycytidine (5-Aza-CdR) or/and trichostatin A (TSA) were investigated by MSP and qRT-PCR respectively. Co-immunoprecipitation was used to detect the interactions between UHRF1 and PRMT5 proteins.

RESULTS

CDH13 and SHP1 promoters were highly methylated (81.36% and 86.44%, respectively) in endometrial carcinoma, while CDH13 promoter methylation was also present in complex hyperplasia and atypical hyperplasia (51.72% and 50.00%, respectively). Methylation of CDH13 and SHP1 promoters was associated with age and tumor differentiation or muscular infiltration depth. CDH13 and SHP1 promoters were completely methylated in endometrial carcinoma cell lines and were partially reversed by 5-Aza-CdR or TSA to induce mRNA levels (P<0.01). After combined treatment with these two agents, methylation of CDH13 and SHP1 promoters was completely reversed and expression of their mRNA was significantly increased (P<0.01). Moreover, PRMT5 could bind to UHRF1 and down-regulated by 5-Aza-CdR and/or TSA treatment (P<0.05).

CONCLUSIONS

Our data demonstrate for the first time that SHP1 methylation has high specificity for diagnosis of endometrial carcinoma, while CDH13 promoter methylation plays a role in the earlier stage. Furthermore, UHRF1 could form a complex with PRMT5 to contribute to the endometrial carcinogenesis.

Environmental (nongenetic) factors in gynecological cancers: update and future perspectives

Globally, gynecological cancers comprise three of the seven most common female cancers and are responsible for more than 1,000,000 new cases and 500,000 deaths annually. This review summarizes current knowledge regarding the role of environmental factors in gynecological cancer etiology and survival, focusing on those that are potentially amenable to intervention. Strong associations with use of exogenous hormones are countered by opposing risks of breast cancer, thus current hormonal preparations are not an option for prevention. Weight control would reduce risk of endometrial cancer but this and other lifestyle modifications are unlikely to have a major effect on gynecological cancer mortality rates. There is little information regarding the potential for lifestyle changes to improve outcomes for women with gynecological cancer.

Weight cycling and cancer incidence in a large prospective US cohort

Weight cycling, which consists of repeated cycles of intentional weight loss and regain, is common among individuals who try to lose weight. Some evidence suggests that weight cycling may affect biological processes that could contribute to carcinogenesis, but whether it is associated with cancer risk is unclear. Using 62,792 men and 69,520 women enrolled in the Cancer Prevention Study II Nutrition Cohort in 1992, we examined the association between weight cycling and cancer incidence. Weight cycles were defined by using baseline questions that asked the number of times ≥10 pounds (4.54 kg) was purposely lost and later regained. Multivariable-adjusted hazard ratios and 95% confidence intervals for all cancer and 15 individual cancers were estimated by using Cox proportional hazards regression. During up to 17 years of follow-up, 15,333 men and 9,984 women developed cancer. Weight cycling was not associated with overall risk of cancer in men (hazard ratio = 0.96, 95% confidence interval: 0.83, 1.11 for ≥20 cycles vs. no weight cycles) or women (hazard ratio = 0.96, 95% confidence interval: 0.86, 1.08) in models that adjusted for body mass index and other covariates. Weight cycling was also not associated with any individual cancer investigated. These results suggest that weight cycling, independent of body weight, is unlikely to influence subsequent cancer risk.

Laparoscopy versus laparotomy for the management of endometrial carcinoma in morbidly obese patients: a prospective study

OBJECTIVE

To compare the results of total laparoscopic hysterectomy and total abdominal hysterectomy in morbidly obese women with early stage endometrial cancer.

MATERIAL AND METHODS

This prospective study was conducted on 140 morbidly obese women with body mass indices ≥35 kg/m(2) and presenting with clinical stage 1 endometrial cancer. The patients underwent total laparoscopic hysterectomy (n=70) or total abdominal hysterectomy (n=70), bilateral salpingo-oophorectomy, pelvic lymphadenectomy, and peritoneal washing. Age, parity, menopausal status, weight, height, medical problems, history of previous laparotomy, surgical procedure, operative time, estimated amount of blood loss, preoperative hematocrit, postoperative hematocrit, operative complications, conversion to laparotomy, need for intraoperative or postoperative blood transfusion, intraoperative and postoperative complications, secondary surgery, tumor stage, grade, histology, number of recovered lymph nodes, and visual pain scores of the patients were recorded.

RESULTS

Postoperative complications were significantly higher in the laparotomy group. Hospital stay in the laparoscopy group was significantly lower than that in the laparotomy group. The visual pain scores were significantly higher in the laparotomy group on the first, second, and third postoperative days and on the day of discharge from the hospital. Resuming activity took a significantly longer time in the laparotomy group (34.70 days) than in the laparoscopic group (17.89 days).

CONCLUSION

With the availability of skilled endoscopic surgeons, most obese women with early stage endometrial cancer can be safely managed by performing laparoscopy with an excellent surgical outcome, shorter hospitalization, less postoperative pain, and faster resumption of full activity.

Overweight, obesity and endometrial cancer risk: results from a systematic review and meta-analysis

AIM

Findings from recent studies suggest that obesity may be associated with an increased risk of endometrial cancer, but several earlier studies were less conclusive. Here we strive to estimate this relationship in a meta-analysis of published data.

METHODS

We searched Pubmed and Embase for studies on body mass index and the risk of endometrial cancer, published from 1989 to 2011. Data were independently extracted and analyzed using random or fixed effects meta-analysis depending on the degree of heterogeneity.

RESULTS

Seven cohort studies and 11 case-control studies were included in the meta-analysis. Overall, the conditions of excess body weight ([EBW] defined as body mass index [BMI] ≥25 kg/m²), obesity (BMI ≥30 kg/m²) and overweight (25< BMI <30 kg/m²) were associated with an increased risk of endometrial cancer (relative risk [RR] for EBW=1.62, 95% confidence interval [CI], 1.39-1.89; for obesity RR=2.54, 95% CI, 2.11-3.06; for overweight RR=1.32, 95% CI, 1.16-1.50). Subgroup analyses showed that the positive associations were independent of study design, geographic locations, self-reported BMI, alcohol use, smoking habit, history of diabetes, hormone therapy, age at menarche, age at menopause, parity, and age at first full term pregnancy. However, there was no statistically significant association between EBW and endometrial cancer risk for measured BMI (for EBW RR=1.29, 95% CI, 0.66-2.53).

CONCLUSIONS

The findings from this meta-analysis strongly support that the conditions of EBW, overweight, and obesity are all associated with an increased risk of endometrial cancer. Also, the strength of the association increases with increasing BMI.

The occurrence of fetal microchimeric cells in endometrial tissues is a very common phenomenon in benign uterine disorders, and the lower prevalence of fetal microchimerism is associated with better uterine cancer prognoses

This is the first study carried out to describe the role of fetal microchimerism (FM) in the pathogenesis of uterine cancer. The prevalence and concentration of male fetal microchimeric cells (FMCs) were examined in endometrial tissues in relation to subtypes of uterine cancer, and the histological grade and stage of the tumor. FM occurrence was analyzed in relation to risk factors, including hypertension, obesity, type 2 diabetes, dyslipidemia, age at cancer diagnosis, and patient pregnancy history. The prevalence and concentration of FMCs were examined in endometrial tissues using real-time polymerase chain reaction, SRY and β-globin sequences as markers for male fetal FMCs and total DNA. The studied group involved 47 type 1 endometrial cancers, 28 type 2 endometrial cancers, and 41 benign uterine diseases. While the prevalence of FM was decreased only in type 1 endometrial cancer, compared with benign uterine disorders (38.3% vs.70.7%; odds ratio [OR]=0.257, 95% confidence interval [CI]: 0.105 to 0.628, p=0.003), FMC concentrations did not differ within examined groups. The lower FM prevalence was detected in low-grade (grade 1 and grade 2) endometrioid cancer (38.3% vs. 70.7%, OR=0.256, 95% CI: 0.105 to 0.627, p=0.003) and in FIGO 1 tumors (40.7% vs. 70.7%, OR=0.285, 95% CI: 0.120 to 0.675, p=0.004). No correlation between FM prevalence or FMC concentrations and risk factors was demonstrated. A lower prevalence of male FM seemed to be associated with better prognoses in uterine cancer based on tumor subtype, histological grade, and stage of the tumor.

Anthropometric measures and the risk of endometrial cancer, overall and by tumor microsatellite status and histological subtype

Obesity is an established risk factor for endometrial cancer, but this association is not well understood for subtypes of endometrial cancer. We evaluated the association of recent and adult-life obesity with subtypes of endometrial cancer based on microsatellite status (microsatellite-stable (MSS) vs. microsatellite-instable (MSI)) and histology (type I vs. type II). Analyses were based on a population-based case-control study (524 cases and 1,032 controls) conducted in Alberta, Canada (2002-2006) and included the following groupings of subtypes: MSS = 337 and MSI = 130; type I = 458 and type II = 66. Logistic and polytomous logistic regression were used to estimate odds ratios and 95% confidence intervals for overall endometrial cancer and subtypes of endometrial cancer, respectively. The risks of all subtypes of endometrial cancer, except type II, increased with an increase in all of the anthropometric characteristics examined. The risks for MSI tumors were suggestively stronger than those for MSS tumors; the risk with high (≥30) body mass index (weight (kg)/height (m)(2)) was significantly stronger for MSI tumors (odds ratio = 4.96, 95% confidence interval: 2.76, 8.91) than for MSS tumors (odds ratio = 2.33, 95% confidence interval: 1.66, 3.28) (P-heterogeneity = 0.02). Obesity is associated with most subtypes of endometrial cancer, and further studies are warranted to elucidate the biological mechanisms underlying the stronger risk for the MSI subtype with a high body mass index.

Obesity and gynecologic cancer etiology and survival

The prevalence of overweight and obesity in the United States and elsewhere has increased dramatically in recent decades. It has long been known that obese women have an increased risk of developing endometrial cancer, but recent studies suggest this association is strongest for the most common low-grade endometrioid endometrial cancers and weaker for the other histologic subtypes. There are insufficient data to assess whether obesity affects endometrial cancer-specific survival or whether the relation with all-cause mortality is similar to that seen in the general population. Recent data suggest obesity also increases risk of ovarian cancer, although it may not influence risk of the high-grade serous cancers that account for the majority of ovarian cancer deaths, and that it is also associated with poorer outcomes. There is currently insufficient evidence to draw any clear conclusions regarding the relation between obesity and risk of/survival from other gynecologic cancers although there are suggestions that obesity may increase risk of cervical cancer, particularly adenocarcinoma, and perhaps vulvar cancer. Possible mechanisms whereby obesity might influence gynecologic cancer risk and survival include: its strong association with endogenous estrogen levels among postmenopausal women, its effects on glucose metabolism, its effects on the wide range of adipocytokines and inflammatory mediators that are produced by adipose tissue and altered in concentration among obese individuals, and its potential effects on patient management, particularly with regard to chemotherapy dosing.

A systematic review of the impact of weight loss on cancer incidence and mortality

Obesity is well recognized as a significant risk factor for certain cancers; however, a corresponding risk reduction with weight loss is not yet clearly defined. This review aims to examine the literature investigating the effect of all types of weight loss on cancer incidence and mortality, and to more clearly describe the relationship between these two factors. A literature search identified 34 publications reporting weight loss data in relation to cancer incidence or mortality. All except one were observational studies and the majority used self-reported weights and did not define intentionality of weight loss. 16/34 studies found a significant inverse association between weight loss and cancer incidence or mortality. The remainder returned null findings. The observed association was more consistently seen in studies that investigated the effect of intentional weight loss (5/6 studies) and the risk reduction was greatest for obesity-related cancers and in women. In conclusion, intentional weight loss does result in a decreased incidence of cancer, particularly female obesity-related cancers. However, there is a need for further evaluation of sustained intentional weight loss in the obese with less reliance on self-reported weight data and more focus on male populations.

Postmenopausal endometrial cancer risk and body size in early life and middle age: prospective cohort study

Background:

Greater adiposity in early life has been linked to increased endometrial cancer risk in later life, but the extent to which this association is mediated through adiposity in later life is unclear.

Methods:

Among postmenopausal women who had never used menopausal hormone therapies and reported not having had a hysterectomy, adjusted relative risks (RRs) of endometrial cancer were estimated using Cox regression.

Results:

Among 249 791 postmenopausal women with 7.3 years of follow-up on average (1.8 million person-years), endometrial cancer risk (n=1410 cases) was strongly associated with current body mass index (BMI) at baseline (RR=1.87 per 5 kg m⁻² increase in BMI, 95% confidence interval (CI): 1.77–1.96). Compared with women thinner than average at age 10, the increased risk among women plumper at age 10 (RR=1.27, 95% CI: 1.09–1.49) disappeared after adjustment for current BMI (RR=0.90, 95% CI: 0.77–1.06). Similarly, compared with women with clothes size 12 or less at age 20, the increased risk among women with clothes size 16 or larger (RR=1.87, 95% CI: 1.61–2.18) was not significant after adjustment for current BMI (RR=1.03, 95% CI: 0.88–1.22).

Conclusion:

Among women who have never used hormone therapy for menopause, the association between body size in early life and endometrial cancer risk in postmenopausal women can be largely explained by women’s current BMI.

Effect of the timing of weight cycling during adulthood on mortality risk in overweight and obese postmenopausal women

Inconsistent results exist for whether or not weight cycling (WgtC) and weight variability (WgtV) increase mortality risk. The aim of this study was to examine the effect of WgtC and WgtV during adulthood on mortality risk. Data was obtained from the Women's Health Initiative (WHI) observational study (OS) dataset, acquired from the National Heart, Lung and Blood Institute (N = 47,473 overweight and obese women; age 50-79 years). Women were categorized (stable; WgtV: weight-gainer or loser; or WgtC) based on weight changes during early (18-35 years), mid (35-50 years), and late (50 years to current age) adulthood. Those with weight changes of <5% during all three time-periods were classified as being stable-weight. Weight-gainers were those with at least one period of weight-gain (≥5%) without a period of weight-loss (≥5%), and weight-losers were those with at least one period of loss without a period of gain during all time-periods. Those who experienced both a period of weight-gain and loss (≥5%) were categorized as WgtC. Compared to stable-weight individuals, WgtC and WgtV across adulthood were not significantly associated with mortality risk when the age-period of weight change was not considered. However, when considering the age period, increased mortality risk was observed for every 5 kg of weight-gain during early (hazard ratio (HR) = 1.04 (1.00-1.07)) or mid-adulthood (HR = 1.05 (1.02-1.08)), or for every 5 kg of weight-loss since mid (HR = 1.12 (1.01-1.24)) or late-adulthood (HR = 1.12 (1.04-1.20)). In conclusion, merely investigating WgtC and WgtV by weight changes across adulthood may not be sufficient to fully describe mortality risk, and the age at which the weight change occurred might be as important to consider.

Weight gain during adulthood and body weight at age 20 are associated with the risk of endometrial cancer in Japanese women

BACKGROUND

Current obesity is an established risk factor for endometrial cancer; however, the roles of weight gain during adulthood and obesity in early adulthood on endometrial cancer have not been elucidated. Here, we conducted a case-control study comprising 222 histologically diagnosed incident endometrial cancer cases and 2162 age- and menstrual-status matched non-cancer controls.

METHODS

Information on current body weight, weight and height at age 20 years, and lifestyle/environmental factors was obtained from a self-administered questionnaire. Subjects were classified into 3 groups according to change in body mass index (BMI, kg/m(2)) from age 20 years to enrollment (≤0 [reference], 0-3, and >3 kg/m(2)). The effects of adult BMI change and obesity in early adulthood were evaluated using an unconditional logistic regression model adjusted for potential confounders.

RESULTS

A high BMI at age 20 (BMI ≥25, BMI <25 as reference) was significantly positively associated with endometrial cancer risk (P = 0.005), as was a BMI increase during adulthood (0-3 BMI change, multivariate odds ratio [OR] = 1.28, 95% confidence interval [CI] = 0.88-1.87; >3 BMI change, OR = 2.02, 95% CI = 1.38-2.96; P-trend < 0.001). Parity and BMI at age 20 appeared to modify the effect of weight gain on cancer risk, albeit without statistical significance. This positive association of weight gain with risk was observed only for endometrioid adenocarcinoma.

CONCLUSIONS

The results show that endometrial cancer is positively associated with obesity at age 20 and weight gain during adulthood among Japanese women.

Weight cycling and cancer: weighing the evidence of intermittent caloric restriction and cancer risk

Overweight and obese individuals frequently restrict caloric intake to lose weight. The resultant weight loss, however, typically is followed by an equal or greater weight gain, a phenomenon called weight cycling. Most attention to weight cycling has focused on identifying its detrimental effects, but preclinical experiments indicating that intermittent caloric restriction or fasting can reduce cancer risk have raised interest in potential benefits of weight cycling. Although hypothesized adverse effects of weight cycling on energy metabolism remain largely unsubstantiated, there is also a lack of epidemiologic evidence that intentional weight loss followed by regain of weight affects chronic-disease risk. In the limited studies of weight cycling and cancer, no independent effect on postmenopausal breast cancer but a modest enhancement of risk for renal cell carcinoma, endometrial cancer, and non-Hodgkin's lymphoma have been reported. An effect of either intermittent caloric restriction or fasting in protecting against cancer is not supported by the majority of rodent carcinogenesis experiments. Collectively, the data argue against weight cycling and indicate that the objective of energy balance-based approaches to reduce cancer risk should be to strive to prevent adult weight gain and maintain body weight within the normal range defined by body mass index.

Case-control study of the metabolic syndrome and metabolic risk factors for endometrial cancer

BACKGROUND

Metabolic syndrome may predict endometrial cancer risk better than diabetes, hypertension, dyslipidemia, dysglycemia, or weight alone, but few studies have examined this issue.

METHODS

We conducted a population-based case-control study in Alberta, Canada (2002-2006) that included 515 incident endometrial cancer cases and 962 frequency age-matched controls. Data were collected through in-person interviews, anthropometric measurements, and 8-hour fasting bloods drawn either pre- or postsurgery. Bloods were analyzed using quantitative colorimetric or absorbance-based assays (ELISA), specific to metabolic syndrome markers. Metabolic syndrome was defined using harmonized guidelines requiring presence of ≥ 3 of the following risk factors: waist circumference ≥ 88 cm, triglycerides ≥ 150 mg/dL, high-density lipoprotein cholesterol <50 mg/dL, treatment of previously diagnosed hypertension, and fasting blood glucose ≥ 100 mg/dL. OR and 95% CIs for endometrial cancer risk with presence of metabolic syndrome and individual metabolic syndrome components were estimated using logistic regression analysis.

RESULTS

Metabolic syndrome was significantly more prevalent among cases (62%) than controls (38%). A statistically significant increased risk for endometrial cancer was observed for metabolic syndrome (OR = 1.53; 95% CI: 1.17-2.00), as well as for some of the individual components of metabolic syndrome including waist circumference ≥ 88 cm (OR = 1.57; 95% CI: 1.18-2.08), hypertension (OR = 1.57; 95% CI: 1.18-2.09), and fasting blood glucose ≥ 100 mg/dL (OR = 1.31; 95% CI: 1.03-1.67). Some evidence for effect modification by menopausal status and body mass index was also found.

CONCLUSION

Metabolic syndrome is clearly associated with increased endometrial cancer risk.

IMPACT

Targeting the entire metabolic syndrome may optimize endometrial cancer risk reduction.

Body mass index in early adulthood and endometrial cancer risk for mismatch repair gene mutation carriers

OBJECTIVE

To investigate the association of body mass index (BMI) in early adulthood and endometrial cancer risk for carriers of a germline mutation in a DNA mismatch repair gene.

METHODS

We estimated the association between BMI at age 18-20 years and endometrial cancer risk for mismatch repair gene mutation carriers and, as a comparison group, noncarriers using 601 female carriers of a germline mutation in a mismatch repair gene (245 MLH1, 299 MSH2, 38 MSH6, and 19 PMS2) and 533 female noncarriers from the Colon Cancer Family Registry using a weighted Cox proportional hazards regression.

RESULTS

During 51,693 person-years of observation, we observed diagnoses of endometrial cancer for 126 carriers and eight noncarriers. For carriers, there was no evidence of an association between BMI at age 20 years and endometrial cancer (adjusted hazard ratio 0.73 per 5 kg/m²; 95% confidence interval [CI], 0.40-1.34; P=.31). For noncarriers, endometrial cancer risk increased by 74% for each 5-kg/m² increment in BMI (adjusted hazard ratio 1.74; 95% CI 1.27-2.37; P<.001). The hazard ratio for BMI and endometrial cancer for noncarriers was greater than for carriers (P=.04).

CONCLUSION

The effect of body mass on endometrial cancer risk depends on the woman's mismatch repair gene mutation carrier status, suggesting obesity-independent endometrial carcinogenesis for carriers.

LEVEL OF EVIDENCE

II.

Anthropometric measures at different ages and endometrial cancer risk

Background:

Endometrial cancer is strongly associated with body mass index (BMI), but the influence of BMI history and of different types of obesity is uncertain.

Ethods:

M A case–control study was carried out in Italy including 454 cases and 908 controls admitted to hospital for acute non-hormone-related conditions. Odds ratios (ORs) and 95% confidence intervals (CIs) were computed using multivariate logistic and spline regression models.

Results:

The OR for BMI >30 at diagnosis compared with 20 to <25 kg m⁻² was 4.08 (95% CI: 2.90–5.74). The association for BMI was monotonic with a possible steeper increase for BMI above 28. Conversely, waist-to-hip ratio (WHR) showed a bell shaped curve with increased OR (2.10; 95% CI: 1.43–3.09) in the intermediate tertile only. After stratification by BMI at diagnosis, history of weight loss and BMI at age 30 did not influence endometrial cancer risk. History of obesity in middle age had a weak and not significant adverse effect among obese women (OR=1.60; 95% CI: 0.52–4.96).

Conclusion:

The predominant importance of recent weight compared to lifetime history, justifies encouraging weight reduction in women at any age.