Intentional Weight Loss and Obesity-Related Cancer Risk

Mendelian randomization unraveled: gender-specific insights into obesity-related phenotypes and colorectal cancer susceptibility

Objective

Evidence has been increasingly pointing towards a potential link between phenotypes related to obesity and the incidence of colorectal cancer. However, confirming this as a direct causal connection remains elusive. This investigation aims to elucidate the causative links between obesity-associated phenotypes and the incidence of colorectal cancer.

Methods

Employing the Two Sample Mendelian Randomization (TwoSampleMR) R package, analyses were conducted using Mendelian randomization (MR) to discern potential causative links between obesity categories sourced from both the Institute for Education and University (IEU) Open GWAS Project and Zenodo, and colorectal tumors (data obtained from IEU Open GWAS and FinnGen). For primary evaluations, the study utilized the Wald ratio and the Inverse Variance Weighting (IVW) methods, while the MR-Egger approach was integrated for sensitivity assessment. Bidirectional Mendelian Randomization (Bidirectional MR), as well as Linkage Disequilibrium (LD) Score Regression with well-imputed HapMap3 single nucleotide polymorphisms (SNPs), were additionally executed. Sensitivity assessments entailed IVW, MR-Egger methodologies to assess heterogeneity and pleiotropy, along with a leave-one-out strategy. Instrumental variables were chosen judiciously based on predetermined P-value thresholds and F-statistics.

Results

Results from MR evaluations did not identify a clear causative link between BMI and colorectal malignancy. Conversely, both measures of obesity, the Waist-Hip Ratio (WHR) and its adjusted form for BMI (WHRadjBMI), displayed a connection to increased risk of colorectal cancer, especially prominent among female subjects. Reverse MR analyses dismissed potential reverse causality between colorectal malignancies and obesity. A significant genetic interplay was observed between WHR, WHRadjBMI, and colorectal cancer instances. Ensuing MR probes spotlighted inflammatory bowel ailment as a protective factor, while salad intake was indicated as a potential risk concerning colorectal malignancies. Sensitivity reviews, which included tests for both pleiotropy and heterogeneity, validated the robustness of the MR findings.

Conclusion

Findings from this research indicate that specific obesity-related parameters, notably WHR and WHRadjBMI, carry a causal relationship with an elevated colorectal cancer risk. The impact is distinctly more evident among females. Such insights might be pivotal for public health deliberations, hinting that individuals boasting a high WHR might necessitate intensified colorectal cancer screenings.

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.

Ketogenic metabolic therapy in conjunction with standard treatment for glioblastoma: A case report

Glioblastoma (GBM) is the most common primary malignant brain tumour in adults. The standard of care consists of surgical resection and concurrent chemoradiation, followed by adjuvant temozolomide chemotherapy. This protocol is associated with a median survival of 12-15 months, and <5% of patients survive >3 years. Ketogenic metabolic therapy (KMT) targets cancer cell metabolism by restricting glucose availability and evoking differential stress resistance and sensitization, which may augment the standard treatments and lead to therapeutic benefit. The present study reports the case of a 64-year-old woman with isocitrate dehydrogenase (IDH)-wildtype GBM who pursued the standard treatment protocol in conjunction with an intensive, multimodal KMT program for 3 years. The KMT program consisted of a series of prolonged (7-day, fluid-only) fasts, which were specifically timed to maximize the tolerability and efficacy of the standard treatments, combined with a time-restricted ketogenic diet on all other days. During the first and second treatment years the patient sustained a glucose ketone index (GKI) of 1.65 and 2.02, respectively, which coincided with complete clinical improvement, a healthy body-mass index and a high quality of life, with no visible progressive tumour detected on imaging at the end of the second year. In the setting of the death of an immediate family member leading to increased life stress, slightly relaxed KMT adherence, and a higher GKI of 3.20, slow cancer progression occurred during the third year. The adverse effects attributed to KMT were mild. Despite the limitations of this case report, it highlights the feasibility of implementing the standard treatment protocol for GBM in conjunction with an intensive, long-term, multimodal and specifically timed KMT program, the potential therapeutic efficacy of which may depend upon achieving as low a GKI as possible.

Crosstalk between obesity and cancer: a role for adipokines

Adipose tissue is a complex organ that is increasingly being recognised as the largest endocrine organ in the body. Adipocytes among multiple cell types of adipose tissue can secrete a variety of adipokines, which are involved in signalling pathways and these can be changed by obesity and cancer. There are proposed mechanisms to link obesity/adiposity to cancer development including adipocytokine dysregulation. Among these adipokines, leptin acts through multiple pathways including the STAT3, MAPK, and PI3K pathways involved in cell growth. Adiponectin has the opposite action from leptin in tumour growth partly because of increased apoptotic responses of p53 and Bax. Visfatin increases cancer cell proliferation through ERK1/2, PI3K/AKT, and p38 which are stimulated by proinflammatory cytokines. Omentin through the PI3K/Akt-Nos pathway is involved in cancer-tumour development. Apelin might be involved through angiogenesis in tumour progressions. PAI-1 via its anti-fibrinolytic activity on cell adhesion and uPA/uPAR activity influence cancer cell growth.

Impact of weight loss after treatment on survival outcomes of overweight and obese patients with early‑stage endometrial cancer

Despite the fact that obesity is the main risk factor for endometrial cancer, there is limited evidence regarding the effects of body weight change on overweight and obese women treated for early-stage endometrial can its impact on cancer outcomes. A retrospective cohort study was performed including all overweight and obese patients with early-stage type-I endometrial cancer that were treated at the Insular University Hospital of Las Palmas (Las Palmas de Gran Canaria, Spain) between January 2007 and December 2019. Body weight change at 12 months of treatment was evaluated, as well as its impact on cancer outcomes. Weight loss ≥5% was independently evaluated regarding its impact on survival. A total of 526 women were studied, of which 152 (28.90%) were overweight (BMI ≥25 and <30) and 374 (71.10%) were obese (BMI ≥30). The median follow-up was 76.17 months, during which time 77 (14.64%) women died. In the survivor group, body weight at initial diagnosis was 86.4±17.9 kg compared with 84.6±16.4 kg 1 year after treatment, which corresponded to a significant mean weight loss of 1.47 kg (P<0.001). However, in the group of non-survivors, body weight at initial diagnosis was 84.7±15.7 kg compared with 84.7±14.6 kg 1 year after treatment, which demonstrated a non-significant mean weight loss of 0.63 kg (P=0.180). When comparing between the patients who maintained or gained ≥5% weight and those who lost ≥5% weight, there were no significant differences taking into account the whole cohort and follow-up time; however, when adjusting for the period between 32 and 98 months, survival was significantly higher in those patients that lost ≥5% of their initial body weight (P=0.025; log-rank test). Based on the final univariate and cer and multivariate analyses, body weight change at 12 months was not indicated to be a factor significantly affecting overall survival; adjusted hazard ratio was 1.01 (95% CI 0.97-1.05, P=0.723). In conclusion, even if greater weight loss is observed in patients with endometrial cancer that survive the disease, no significant impact on survival outcomes is observed based on multivariate analysis.

Trends in the burden of most common obesity-related cancers in 16 Southern Africa development community countries, 1990-2019. Findings from the global burden of disease study

Background

Obesity-related cancers in the 16 Southern African Development Community (SADC) countries is quite prominent. The changes and time trends of the burden of obesity-related cancers in developing countries like SADC remain largely unknown. A descriptive epidemiological analysis was conducted to assess the burden of obesity-related cancers, (liver, esophageal, breast, prostate, colon/rectal, leukemia, ovarian, uterine, pancreatic, kidney, gallbladder/biliary tract, and thyroid cancers) in SADC countries.

Methods

Data from the 2019 Global Burden of Diseases Study was used. Deaths extracted from vital registration, verbal autopsies and ICD codes. Cancer-type, mortality and prevalence per 100,000 population and 95% uncertainty intervals (UIs) were calculated using the Cause of Death Ensemble model and Spatio-Temporal Gaussian process with mixed effects regression models. Annual rates of change (AROCs) between 1990 and 2019 and the corresponding UIs were calculated.

Results

The top age-standardized mortality rates per 100,000 in 2019 for males were leukemia, 20.1(14.4-26.4), esophageal cancer, 15.1 (11.2-19.1), and colon and rectal cancer, 10.3 (8.6-12.6). For females, breast cancer, 20.6 (16.6-25.0), leukemia, 17.1 (11.4-23.7), and esophageal cancer, 8.3 (5.5-10.7), had the leading mortality rates. For males, AROC substantial (p < 0.05) increase for kidney cancer for 11 of the countries (AROC from 0.41% to 1.24%), colon cancer for eight of the countries (from 0.39% to 0.92%), and pancreatic cancer for seven countries (from 0.26% to 1.01%). In females, AROC showed substantial increase for pancreatic cancer for 13 of the countries from (0.34%-1.67%), nine countries for kidney cancer (from 0.27% to 1.02%), seven countries each for breast cancer (0.35%-1.13%), and ovarian cancer (from 0.33% to 1.21%).

Conclusions

There is need for location-specific and culturally appropriate strategies for better nutrition and weight control, and improved screening for all cancers. Health promotion messaging should target kidney, colon, pancreatic, and breast cancers and encourage clinically tested methods of reducing BMI such as increasing personal physical activity and adoption of effective dietary regimes.

Gastrointestinal: Weight gain increases the risk of metachronous advanced colorectal neoplasm observed in post-polypectomy surveillance colonoscopy

BACKGROUND AND AIM

Although obesity is a known risk factor for colorectal neoplasms, the correlation between weight change and colorectal neoplasm is unclear. Thus, we aim to evaluate the association between weight change and advanced colorectal neoplasm (ACRN) recurrence during post-polypectomy surveillance colonoscopy.

METHODS

This retrospective cohort study included 7473 participants diagnosed with colorectal neoplasms between 2003 and 2010 who subsequently underwent surveillance colonoscopies until 2020. We analyzed the association between the risk of metachronous ACRN and weight change, defining stable weight as a weight change of <3% and weight gain as a weight increase of ≥3% from baseline during the follow-up period.

RESULTS

During a median 8.5 years of follow-up, 619 participants (8.3%) developed ACRN. Weight gain was reported as an independent risk factor for metachronous ACRN in a time-dependent Cox analysis. A weight gain of 3-6% and ≥6% had adjusted hazard ratios (AHRs) of 1.48 (95% confidence interval [CI]: 1.19-1.84) and 2.14 (95% CI: 1.71-2.69), respectively. Participants aged 30-49 and 50-75 years with weight gain of ≥6% showed AHRs of 2.88 (95% CI: 1.96-4.21) and 1.90 (95% CI: 1.43-2.51), respectively. In men and women, weight gain of ≥3% was significantly correlated with metachronous ACRN.

CONCLUSIONS

Weight gain is associated with an increased risk of metachronous ACRN. Furthermore, weight gain is associated with the recurrence of ACRN in both men and women regardless of age.

Post-diagnosis weight trajectories and mortality among women with breast cancer

Weight gain after breast cancer diagnosis is associated with adverse health outcomes. Yet, few studies have characterized post-diagnosis weight change in the modern treatment era or populations most at risk for weight changes. Among women diagnosed with stages I-III breast cancer in the Smilow Care Network (2013-2019; N = 5441), we abstracted demographic and clinical characteristics from electronic health records and survival data from tumor registries. We assessed if baseline characteristics modified weight trajectories with nonlinear multilevel mixed-effect models. We evaluated body mass index (BMI) at diagnosis and weight change 1-year post-diagnosis in relation to all-cause and breast cancer-specific mortality with Cox proportional hazard models. Women had 34.4 ± 25.5 weight measurements over 3.2 ± 1.8 years of follow-up. Weight gain was associated with ER/PR-, HER2+ tumors, BMI ≤ 18.5 kg/m2, and age ≤ 45 years (+4.90 kg (standard error [SE] = 0.59), +3.24 kg (SE = 0.34), and +1.75 kg (SE = 0.10), respectively). Weight loss was associated with BMI ≥ 35 kg/m2 and age ≥ 70 years (-4.50 kg (SE = 0.08) and -4.34 kg (SE = 0.08), respectively). Large weight loss (≥10%), moderate weight loss (5-10%), and moderate weight gain (5-10%) 1-year after diagnosis were associated with higher all-cause mortality (hazard ratio [HR] = 2.93, 95% confidence interval [CI] = 2.28-3.75, HR = 1.32, 95% CI = 1.02-1.70 and HR = 1.39, 95% CI = 1.04-1.85, respectively). BMI ≥ 35 kg/m2 or BMI ≤ 18.5 kg/m2 at diagnosis were also associated with higher all-cause mortality. Weight change after a breast cancer diagnosis differed by demographic and clinical characteristics highlighting subgroups at-risk for weight change during a 5-year period post-diagnosis. Monitoring and interventions for weight management early in clinical care are important.

Dietary fat and lipid metabolism in the tumor microenvironment

Metabolic reprogramming has been considered a core hallmark of cancer, in which excessive accumulation of lipids promote cancer initiation, progression and metastasis. Lipid metabolism often includes the digestion and absorption of dietary fat, and the ways in which cancer cells utilize lipids are often influenced by the complex interactions within the tumor microenvironment. Among multiple cancer risk factors, obesity has a positive association with multiple cancer types, while diets like calorie restriction and fasting improve health and delay cancer. Impact of these diets on tumorigenesis or cancer prevention are generally studied on cancer cells, despite heterogeneity of the tumor microenvironment. Cancer cells regularly interact with these heterogeneous microenvironmental components, including immune and stromal cells, to promote cancer progression and metastasis, and there is an intricate metabolic crosstalk between these compartments. Here, we focus on discussing fat metabolism and response to dietary fat in the tumor microenvironment, focusing on both immune and stromal components and shedding light on therapeutic strategies surrounding lipid metabolic and signaling pathways.

Randomized Trial Evaluating a Self-Guided Lifestyle Intervention Delivered via Evidence-Based Materials versus a Waitlist Group on Changes in Body Weight, Diet Quality, Physical Activity, and Quality of Life among Breast Cancer Survivors

Background: Lifestyle interventions for breast cancer survivors have proved effective at stimulating positive behavior change and promoting healthy weight loss, although integrating these programs into clinical practice is challenging. We evaluated the effect of a 6-month, unsupervised, self-guided, lifestyle intervention using printed materials and online videos vs. waitlist group on body weight for breast cancer survivors. Methods: The Lifestyle, Exercise and Nutrition (LEAN) Self-Guided trial randomized breast cancer survivors with a body mass index ≥25 kg/m2 to a 6-month lifestyle intervention (N = 102) or waitlist group (N = 103). Effects of the intervention on self-reported body weight, physical activity (PA), diet quality (via Health Eating Index-2010 (HEI-2010)), and quality of life were assessed using mixed model repeated measures analysis. Results: At 6 months, the intervention arm had significantly greater weight loss compared with the waitlist group (mean difference = -1.3 kg, 95% confidence interval [CI] = -2.5, -0.13). We observed suggestive improvements in PA (mean difference = 18.7 min/week, 95% CI = -24.2, 61.6), diet quality (mean difference in HEI = 3.2 points, 95% CI = -0.20, 6.5), and fatigue (mean difference in Functional Assessment of Chronic Illness Therapy-Fatigue scale = 1.4 points, 95% CI = -1.1, 3.9). Conclusions: The LEAN Self-Guided intervention led to favorable weight changes over 6 months. Low-resource-intensive programs have the potential to be delivered in diverse healthcare settings and may support breast cancer survivors in achieving a healthy body weight.

Novel Treatments for Obesity: Implications for Cancer Prevention and Treatment

It is now established that obesity is related to a higher incidence of cancer during a lifespan. The effective treatment of obesity opens up new perspectives in the treatment of a relevant modifiable cancer risk factor. The present narrative review summarizes the correlations between weight loss in obesity and cancer. The current knowledge between obesity treatment and cancer was explored, highlighting the greatest potential for its use in the treatment of cancer in the clinical setting. Evidence for the effects of obesity therapy on proliferation, apoptosis, and response to chemotherapy is summarized. While more studies, including large, long-term clinical trials, are needed to adequately evaluate the relationship and durability between anti-obesity treatment and cancer, collaboration between oncologists and obesity treatment experts is increasingly important.

[Obesity and Colorectal Cancer]

The prevalence of obesity has increased significantly worldwide, and this trend is likely to continue in the coming years. There is substantial evidence that obesity plays a crucial role in the development of colorectal cancer. Epidemiological data have consistently demonstrated a correlation between obesity and colorectal cancer. Insulin resistance, hyperinsulinemia, chronic inflammation, altered levels of growth factors, adipocytokines, and various hormones are plausible biological mechanisms. In addition, obesity has been shown to have an impact on recurrence, treatment success, and overall survival. There are some reports, although the evidence is not conclusive, that weight loss and lifestyle changes such as dietary modification and physical activity can reduce the risk of colorectal cancer. The understanding that obesity is a potentially modifiable risk factor that can affect the incidence and prognosis of colorectal cancer is crucial knowledge that can have an impact on the prevention and treatment of the condition.

Body size over the adult life course and the risk of colorectal cancer among postmenopausal women

OBJECTIVE

To assess the associations among several anthropometric measures, as well as BMI trajectories and colorectal cancer (CRC) risk in older women.

DESIGN

Prospective cohort study.

SETTING

Forty clinical centres in the USA.

PARTICIPANTS

Totally, 79 034 postmenopausal women in the Women's Health Initiative Observational Study.

RESULTS

During an average of 15·8 years of follow-up, 1514 CRC cases were ascertained. Five BMI trajectories over 18-50 years of age were identified using growth mixture model. Compared with women who had a normal BMI at age 18, women with obesity at age 18 had a higher risk of CRC (HR 1·58, 95 % CI 1·02, 2·44). Compared with women who kept relatively low normal body size during adulthood, women who progressed from normal to obesity (HR 1·29, 95 % CI 1·09, 1·53) and women who progressed from overweight to obesity (HR 1·37, 95 % CI 1·13, 1·68) had higher CRC risks. A weight gain > 15 kg from age 18 to 50 (HR 1·20, 95 % CI 1·04, 1·40) and baseline waist circumference > 88 cm (HR 1·33, 95 % CI 1·19, 1·49) were associated with higher CRC risks, compared with stable weight and waist circumference ≤ 88 cm, respectively.

CONCLUSION

Women who have a normal weight in early adult life and gain substantial weight later, as well as those who are persistently heavy over adulthood, demonstrated a higher risk of developing CRC. Our study highlights the importance of maintaining a healthy body weight over the life course for reducing the risk of developing CRC in women.

Obesity, diabetes, and cancer: epidemiology, pathophysiology, and potential interventions

The proportion of deaths attributable to cancer is rising, and malignant neoplasms have become the leading cause of death in high-income countries. Obesity and diabetes are now recognized as risk factors for several types of malignancies, especially endometrial, colorectal, and postmenopausal breast cancers. Mechanisms implicated include disturbances in lipid-derived hormone secretion, sex steroids biosynthesis, hyperinsulinemia, and chronic inflammation. Intentional weight loss is associated with a mitigation of risk for obesity-related cancers, a phenomenon observed specially with bariatric surgery. The impact of pharmacological interventions for obesity and diabetes is not uniform: while metformin seems to protect against cancer, other agents such as lorcaserin may increase the risk of malignancies. However, these interpretations must be carefully considered, since most data stem from bias-prone observational studies, and high-quality randomized controlled trials with appropriate sample size and duration are needed to achieve definite conclusions. In this review, we outline epidemiological and pathophysiological aspects of the relationship between obesity, diabetes, and malignancies. We also highlight pieces of evidence regarding treatment effects on cancer incidence in these populations.

Thyroid Nodules and Obesity

A widely discussed topic in the pathophysiology of thyroid nodules is the role of obesity, a state that leads to increased systemic inflammatory markers. Leptin plays a vital role in forming thyroid nodules and cancer through several mechanisms. Together with chronic inflammation, there is an augmentation in the secretion of tumor necrosis factor (TNF) and the cytokine interleukin 6 (IL-6), which contributed to cancer development, progression and metastasis. In addition, leptin exerts a modulatory action in the growth, proliferation and invasion of thyroid carcinoma cell lines via activating various signal pathways, such as Janus kinase/signal transducer and activator of transcription, mitogen-activated protein kinase (MAPK) and/or phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt). Through several proposed mechanisms, aberrant endogenous estrogen levels have been suggested to play a vital role in the development of both benign and malignant nodules. Metabolic syndrome triggers the development of thyroid nodules by stimulating thyroid proliferation and angiogenesis due to hyperinsulinemia, hyperglycemia and dyslipidemia. Insulin resistance influences the distribution and structure of the thyroid blood vessels. Insulin growth factor 1 (IGF-1) and insulin affect the regulation of the expression of thyroid genes and the proliferation and differentiation of thyroid cells. TSH can promote the differentiation of pre-adipocytes to mature adipocytes but also, in the presence of insulin, TSH possesses mitogenic properties. This review aims to summarize the underlying mechanisms explaining the role of obesity in the pathophysiology of thyroid nodules and discuss potential clinical implications.

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.

Metabolic and bariatric surgery and obesity pharmacotherapy for cancer prevention: current status and future possibilities

Obesity is a chronic, relapsing, progressive disease of excess adiposity that increases the risk of developing at least 13 types of cancer. This report provides a concise review of the current state of the science regarding metabolic and bariatric surgery and obesity pharmacotherapy related to cancer risk. Meta-analyses of cohort studies report that metabolic and bariatric surgery is independently associated with a lower risk of incident cancer than nonsurgical obesity care. Less is known regarding the cancer-preventive effects of obesity pharmacotherapy. The recent approval and promising pipeline of obesity drugs will provide the opportunity to understand the potential for obesity therapy to emerge as an evidence-based cancer prevention strategy. There are myriad research opportunities to advance our understanding of how metabolic and bariatric surgery and obesity pharmacotherapy may be used for cancer prevention.

Impact of risk factors on early cancer evolution

Recent identification of oncogenic cells within healthy tissues and the prevalence of indolent cancers found incidentally at autopsies reveal a greater complexity in tumor initiation than previously appreciated. The human body contains roughly 40 trillion cells of 200 different types that are organized within a complex three-dimensional matrix, necessitating exquisite mechanisms to restrain aberrant outgrowth of malignant cells that have the capacity to kill the host. Understanding how this defense is overcome to trigger tumorigenesis and why cancer is so extraordinarily rare at the cellular level is vital to future prevention therapies. In this review, we discuss how early initiated cells are protected from further tumorigenesis and the non-mutagenic pathways by which cancer risk factors promote tumor growth. By nature, the absence of permanent genomic alterations potentially renders these tumor-promoting mechanisms clinically targetable. Finally, we consider existing strategies for early cancer interception with perspectives on the next steps for molecular cancer prevention.

Gynecological malignancies and obesity

The global pandemic of obesity has had a significant impact on gynecological malignancies, most notably endometrial cancer. It has resulted in worldwide increases in the incidence of endometrial cancer and a change in patient demographics, resulting in more diagnoses than ever before being made in pre-menopausal women, who are often keen to pursue fertility-sparing treatments. Obesity increases the risk of gynecological cancers by creating a pro-carcinogenic environment of unopposed estrogen, hyperinsulinemia, and chronic inflammation. It can present both a diagnostic challenge and strongly influence management decisions, including the practicalities of performing surgery, increase anesthetic risks, and alter response rates to adjuvant and medical therapies. Obesity may also influence endometrial cancer mortality and certainly contributes to poorer overall survival due to an excess of deaths related to cardiovascular disease. Weight loss may well, therefore, be the key to the prevention of gynecological cancers and their recurrence.

Metabolic reprogramming and interventions in endometrial carcinoma

Cancer cells are usually featured by metabolic adaptations that facilitate their growth, invasion, and metastasis. Thus, reprogramming of intracellular energy metabolism is currently one of the hotspots in the field of cancer research. Whereas aerobic glycolysis (known as the Warburg effect) has long been considered a dominant form of energy metabolism in cancer cells, emerging evidence indicates that other metabolic forms, especially oxidative phosphorylation (OXPHOS), may play a critical role at least in some types of cancer. Of note, women with metabolic syndromes (MetS), including obesity, hyperglycemia, dyslipidemia, and hypertension, have an increased risk of developing endometrial carcinoma (EC), suggesting a close link between metabolism and EC. Interestingly, the metabolic preferences vary among EC cell types, particularly cancer stem cells and chemotherapy-resistant cells. Currently, it is commonly accepted that glycolysis is the main energy provider in EC cells, while OXPHOS is reduced or impaired. Moreover, agents specifically targeting the glycolysis and/or OXPHOS pathways can inhibit tumor cell growth and promote chemosensitization. For example, metformin and weight control not only reduce the incidence of EC but also improve the prognosis of EC patients. In this review, we comprehensively overview the current in-depth understanding of the relationship between metabolism and EC and provide up-to-date insights into the development of novel therapies targeting energy metabolism for auxiliary treatment in combination with chemotherapy for EC, especially those resistant to conventional chemotherapy.

Longevity, tumor, and physical vitality in rats consuming ginsenoside Rg1

Background

Effects of the major ginsenoside Rg1 on mammalian longevity and physical vitality are rarely reported.

Purpose

To examine longevity, tumor, and spontaneous locomotor activity in rats consuming Rg1.

Methods

A total of 138 Wistar rats were randomized into 2 groups: control (N = 69) and Rg1 (N = 69). Rg1 (0.1 mg/kg per day) were orally supplemented from 6 months of age until natural death. Spontaneous mobility was measured by video-tracking together with body composition (dual energy x-ray absorptiometry) and inflammation markers at 5, 14, 21, and 28 months of age.

Results

No significant differences in longevity (control: 706 days; Rg1: 651 days, p = 0.77) and tumor incidence (control: 19%; Rg1: 12%, p = 0.24) were observed between the two groups. Movement distance in the control group declined significantly by ∼60% at 21 months of age, together with decreased TNF-α (p = 0.01) and increased IL-10 (p = 0.02). However, the movement distance in the Rg1 group was maintained ∼50% above the control groups (p = 0.01) at 21 months of age with greater magnitudes of TNF-α decreases and IL-10 increases. Glucose, insulin, and body composition (bone, muscle and fat percentages) were similar for both groups during the entire observation period.

Conclusion

The results of the study suggest a delay age-dependent decline in physical vitality during late life by lifelong Rg1 consumption. This improvement is associated with inflammatory modulation. Significant effects of Rg1 on longevity and tumorigenesis were not observed.

Response to a novel, weight self-awareness plan used in a multi-component lifestyle intervention programme to reduce breast cancer risk factors in older women-Secondary analysis from the ActWELL trial

BACKGROUND

The ActWELL randomised controlled trial assessed the effectiveness of a weight management programme delivered by volunteer lifestyle coaches (LCs) in women attending breast clinics. The intervention focused on caloric intake and physical activity, utilising behavioural change techniques including a weight awareness plan (WAP). The current work is a secondary analysis of the ActWELL data and aims to examine the response to the weight self-awareness plan (used as part of the intervention programme).

METHODS

The LCs invited participants (n = 279) to undertake an implementation intention discussion to formulate a self-weighing (SW) plan. Bodyweight scales were offered, and recording books provided. The physical activity component of the intervention focused on a walking plan assessed by accelerometers. The LCs contacted participants by telephone monthly and provided personalised feedback. Mann-Whitney tests and chi-squared analysis were used to examine the effect of SW on weight change. A qualitative evaluation utilising semi-structured interviews was also undertaken.

RESULTS

Most participants (96.4%) agreed to set a weekly SW goal and 76 (27%) requested scales. At 12 months, 226 (81%) returned for follow up. The median (interquartile range) weight change for those who self- reported at least one weight (n = 211) was -2.3 kg (-5.0 to 0.0) compared to -1.2 kg (-5.0 to 0.03) in those who did not (n = 14). Participants who reported weights on more than eight occasions (39%) were significantly more likely (p = 0.012) to achieve 5% weight loss compared to those who weighed less often. Low numbers of accelerometers were returned that did not allow for significance testing. Qualitative data (n = 24) indicated that many participants found the WAP helpful and motivating.

CONCLUSIONS

Greater adherence to the WAP initiated by volunteer coaches is associated with achieving 5% weight loss.

Obesity and myeloma: Clinical and mechanistic contributions to disease progression

Obesity and obesogenic behaviors are positively associated with both monoclonal gammopathy of unknown significance (MGUS) and multiple myeloma (MM). As the only known modifiable risk factor, this association has emerged as a new potential target for MM prevention, but little is known about the mechanistic relationship of body weight with MM progression. Here we summarize epidemiological correlations between weight, body composition, and the various stages of myeloma disease progression and treatments, as well as the current understanding of the molecular contributions of obesity-induced changes in myeloma cell phenotype and signaling. Finally, we outline groundwork for the future characterization of the relationship between body weight patterns, the bone marrow microenvironment, and MM pathogenesis in animal models, which have the potential to impact our understanding of disease pathogenesis and inform MM prevention messages.

Joint association of alcohol consumption and adiposity with alcohol- and obesity-related cancer in a population sample of 399,575 UK adults

Obesity and alcohol consumption are both important modifiable risk factors for cancer. We examined the joint association of adiposity and alcohol consumption with alcohol- and obesity-related cancer incidence. This prospective cohort study included cancer-free UK Biobank participants aged 40-69 years. Alcohol consumption was categorised based on current UK guidelines into four groups. We defined three markers of adiposity: body fat percentage (BF %), waist circumference and BMI and categorised each into three groups. We derived a joint alcohol consumption and adiposity marker variable with twelve mutually exclusive categories. Among 399 575 participants, 17 617 developed alcohol-related cancer and 20 214 developed obesity-related cancer over an average follow-up of 11·8 (SD 0·9) years. We found relatively weak evidence of independent associations of alcohol consumption with cancer outcomes. However, the joint association analyses showed that across all adiposity markers, above guideline drinkers who were in the top two adiposity groups had elevated cancer incidence risk (e.g. HR for alcohol-related cancer was 1·53 (95 % CI (1·24, 1·90)) for within guideline drinkers and 1·61 (95 % CI (1·30, 2·00)) for above guideline drinkers among participants who were in the top tertile BF %. Regardless of alcohol consumption status, the risk of obesity-related cancer increased with higher adiposity in a dose-response manner within alcohol consumption categories. Our study provides guidance for public health priorities aimed at lowering population cancer risk via two key modifiable risk factors.

Feasibility and Safety of a Combined Metabolic Strategy in Glioblastoma Multiforme: A Prospective Case Series

Background

Glioblastoma multiforme (GBM) may be susceptible to metabolic strategies such as fasting and ketogenic diets, which lower blood glucose and elevate ketones. Combining these two strategies may be an ideal approach for sustaining a potentially therapeutic glucose ketone index (GKI). In this prospective case series, we observed whether a combined metabolic strategy was feasible, safe, and capable of sustaining a GKI <6 in patients with GBM.

Methods

We provided recommendations and guidelines to 10 GBM patients at various stages of tumour progression and treatment that enabled them to complete a 5–7-day fast every 1–2 months combined with a modified ketogenic diet during the intervening weeks. Patients monitored their blood glucose and ketone levels and body weight. Adverse effects were assessed.

Results

Patients completed a mean of 161 ± 74 days of the combined metabolic strategy, with 34 ± 18 (21%) days of prolonged fasting (mean fast duration: 6.0 ± 1.4 days) and 127 ± 59 (79%) days on the ketogenic diet. The mean GKI for all 10 patients was 3.22 (1.28 during the fasts, 5.10 during the ketogenic diet). Body weight decreased by 8.4 ± 6.9 kg (11.2% decrease in baseline weight). The most common adverse effects attributed to the fasts and ketogenic diet were fatigue, irritability, and feeling lightheaded. The metabolic strategy did not interfere with standard oncological treatments.

Conclusion

This is the first study to observe the feasibility and safety of repeated, prolonged fasting combined with a modified ketogenic diet in patients with GBM. Using minimal support, patients maintained the combined metabolic strategy for 5–6 months while sustaining a potentially therapeutic mean GKI of 3.22. Weight loss was considerable. Adverse effects attributed to the metabolic strategy were mild, and it did not interfere with standard oncological treatments. Study Registration: This study is registered on the Australia New Zealand Clinical Trials Registry, number ACTRN12620001310954. The study was registered on 4 December 2020.

Cancer and Obesity: An Obesity Medicine Association (OMA) Clinical Practice Statement (CPS) 2022

Background

This Obesity Medicine Association (OMA) Clinical Practice Statement (CPS) provides an overview of cancer and increased body fat.

Methods

The scientific information for this CPS is based upon published scientific citations, clinical perspectives of OMA authors, and peer review by the Obesity Medicine Association leadership.

Results

Topics include the increased risk of cancers among patients with obesity, cancer risk factor population-attributable fractions, genetic and epigenetic links between obesity and cancer, adiposopathic and mechanistic processes accounting for increased cancer risk among patients with obesity, the role of oxidative stress, and obesity-related cancers based upon Mendelian randomization and observational studies. Other topics include nutritional and physical activity principles for patients with obesity who either have cancer or are at risk for cancer, and preventive care as it relates to cancer and obesity.

Conclusions

Obesity is the second most common preventable cause of cancer and may be the most common preventable cause of cancer among nonsmokers. This Obesity Medicine Association (OMA) Clinical Practice Statement (CPS) on cancer is one of a series of OMA CPSs designed to assist clinicians in the care of patients with the disease of obesity. Patients with obesity are at greater risk of developing certain types of cancers, and treatment of obesity may influence the risk, onset, progression, and recurrence of cancer in patients with obesity.

Body mass index trajectories, weight gain and risks of liver and biliary tract cancers

BACKGROUND

Little is known about the role of early obesity or weight change during adulthood in the development of liver cancer and biliary tract cancer (BTC).

METHODS

We investigated the associations of body mass index (BMI) and weight trajectories with the risk of liver cancer and BTC in the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial (PLCO). BMI was self-reported at ages 20, 50, and at enrollment. BMI trajectories were determined using latent class growth models. Cox regression was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

During a median follow-up of 15.9 years among 138,922 participants, 170 liver cancer and 143 BTC cases were identified. Compared with those whose BMI does not exceed 25 kg/m2, participants with BMI exceeding 25 kg/m2 at age 20 had increased risks of liver cancer (HR = 2.03, 95% CI: 1.26-3.28) and BTC (HR = 1.99, 95% CI: 1.16-3.39). Compared to participants maintaining normal BMI until enrollment, trajectory of normal weight at age 20 to obesity at enrollment was associated with increased risk for liver cancer (HR = 2.50, 95% CI: 1.55-4.04) and BTC (HR = 1.83, 95% CI: 1.03-3.22). Compared to adults with stable weight (+/-5kg) between age 20 to 50 years, weight gain ≥20 kg between ages 20 to 50 years had higher HRs of 2.24 (95%CI: 1.40-3.58) for liver cancer and 1.86 (95% CI: 1.12-3.09) for BTC.

CONCLUSIONS

Being overweight/obese at age 20, and BMI trajectories that result in being overweight and/or obese, may increase risk for both liver cancer and BTC.

Weight Loss and/or Sulindac Mitigate Obesity-associated Transcriptome, Microbiome, and Protumor Effects in a Murine Model of Colon Cancer

Obesity is associated with an increased risk of colon cancer. Our current study examines whether weight loss and/or treatment with the NSAID sulindac suppresses the protumor effects of obesity in a mouse model of colon cancer. Azoxymethane-treated male FVB/N mice were fed a low-fat diet (LFD) or high-fat diet (HFD) for 15 weeks, then HFD mice were randomized to remain on HFD (obese) or switch to LFD [formerly obese (FOb-LFD)]. Within the control (LFD), obese, and FOb-LFD groups, half the mice started sulindac treatment (140 ppm in the diet). All mice were euthanized 7 weeks later. FOb-LFD mice had intermediate body weight levels, lower than obese but higher than control (P < 0.05). Sulindac did not affect body weight. Obese mice had greater tumor multiplicity and burden than all other groups (P < 0.05). Transcriptomic profiling indicated that weight loss and sulindac each modulate the expression of tumor genes related to invasion and may promote a more antitumor immune landscape. Furthermore, the fecal microbes Coprobacillus, Prevotella, and Akkermansia muciniphila were positively correlated with tumor multiplicity and reduced by sulindac in obese mice. Coprobacillus abundance was also decreased in FOb-LFD mice. In sum, weight loss and sulindac treatment, alone and in combination, reversed the effects of chronic obesity on colon tumor multiplicity and burden. Our findings suggest that an investigation regarding the effects of NSAID treatment on colon cancer risk and/or progression in obese individuals is warranted, particularly for those unable to achieve moderate weight loss.

PREVENTION RELEVANCE

Obesity is a colon cancer risk and/or progression factor, but the underlying mechanisms are incompletely understood. Herein we demonstrate that obesity enhances murine colon carcinogenesis and expression of numerous tumoral procancer and immunosuppressive pathways. Moreover, we establish that weight loss via LFD and/or the NSAID sulindac mitigate procancer effects of obesity.

Review article: obesity and colorectal cancer

BACKGROUND

Obesity is a growing global public health problem. More than half the European and North American population is overweight or obese. Colon and rectum cancers are still the second leading cause of cancer death worldwide, and epidemiological data support an association between obesity and colorectal cancers (CRCs).

AIM

To review the literature on CRC epidemiology in obese subjects, assessing the effects of obesity, including childhood or maternal obesity, on CRC, diagnosis, management, and prognosis, and discussing targeted prophylactic measures.

METHOD

We searched PubMed for obesity/overweight/metabolic syndrome and CRC. Other key words included 'staging', 'screening', 'treatment', 'weight loss', 'bariatric surgery' and 'chemotherapy'.

RESULTS

In Europe, about 11% of CRCs are attributed to overweight and obesity. Epidemiological data suggest that obesity is associated with a 30%-70% increased risk of colon cancer in men, the association being less consistent in women. Visceral fat or abdominal obesity seems to be of greater concern than subcutaneous fat obesity, and any 1 kg/m² increase in body mass index confers more risk (hazard ratio 1.03). Obesity might increase the likelihood of recurrence or mortality of the primary cancer and may affect initial management, including accurate staging. The risk maybe confounded by different factors, including lower adherence to organised CRC screening programmes. It is unclear whether bariatric surgery helps reduce rectal cancer risk.

CONCLUSIONS

Despite a growing body of evidence linking obesity to CRC, many questions remain unanswered, including whether we should screen patients with obesity earlier or propose prophylactic bariatric surgery for certain patients with obesity.

Weight-change trajectory in relation to cancer risk: findings from a nationwide cohort study in South Korea

OBJECTIVE

This study examined relationships between weight-change trajectories and all cancers and obesity-related cancer risks.

METHODS

A total of 1,882,304 men and 899,912 women from the 2002 to 2017 National Health Insurance Service cohort were included. Weight-change trajectories in 2002 to 2009, according to BMI, were determined using group-based trajectory modeling. Cox proportional hazards regression assessed associations between trajectories and cancer incidence.

RESULTS

Overall, >50% of individuals maintained stable weight, as did two-thirds of those in the overweight and obesity groups. A total of 64,725 men and 37,608 women developed incident cancer. Weight stability in overweight or obesity groups was associated with greater cancer risk. In both sexes, higher weight across BMI groups increased risks of all cancers, obesity-related cancers and thyroid, colorectal, stomach, liver, prostate, and postmenopausal breast cancer. Stratified by BMI, weight gain increased risks of all cancers and obesity-related cancers in men with obesity class I and women with overweight. Weight loss decreased risks of obesity-related cancers, thyroid cancer, and kidney cancer among men with overweight, premenopausal breast, endometrial, and ovarian cancer in women with overweight, and obesity-related cancers and thyroid cancer in women with class I obesity.

CONCLUSIONS

Maintaining weight and avoiding weight gain are crucial for reducing cancer risk, but achieving a stable, normal BMI optimizes cancer prevention.

Krebsrisiko bei Prädiabetes und Typ-2-Diabetes mellitus

Krebs ist nun die führende Todesursache bei Typ-2-Diabetes mellitus (T2D). Prädiabetes und T2D erhöhen das Risiko für bestimmte Tumoren. Zu den Prädiabetes- bzw. T2D-assoziierten Malignomen zählen gastrointestinale, gynäkologische, urologische und endokrine Karzinome aber auch Leukämien. Prädiabetes und T2D bedingen eine 1,2- bis 2,7-fach erhöhte Krebssterblichkeit. Zugrundeliegende Mechanismen der Assoziation zwischen T2D und Krebs beinhalten die chronische Hyperglykämie, einen chronischen systemischen Entzündungszustand, oxidativen Stress, Dyslipidämie, die Insulinresistenz sowie chronisch erhöhte Spiegel von insulin-like growth factor 1 (IGF-1) und von Insulin. Eine dauerhafte Gewichtsreduktion kann das Krebsrisiko adipöser T2D-Patienten signifikant senken. Ein gesunder Lebensstil und die regelmäßige Teilnahme an Vorsorgeuntersuchungen sind wichtig und können die Krebsmortalität von Diabetespatienten erheblich verringern.

NAMS 2021 Utian Translational Science SymposiumSeptember 2021, Washington, DCCharting the path to health in midlife and beyond: the biology and practice of wellness

ABSTRACT

Charting the Path to Health in Midlife and Beyond: The Biology and Practice of Wellness was a Translational Science Symposium held on Tuesday, September 21, 2021. Foundational psychosocial and behavioral approaches to promote healthy aging and strategies to disseminate this information were discussed. The following synopsis documents the conversation, describes the state of the science, and outlines a path forward for clinical practice. Wellness, in its broadest sense, prioritizes an orientation toward health, and an embrace of behaviors that will promote it. It involves a journey to improve and maintain physical and mental health and overall well-being to fully engage and live one's best life. It is more about recognizing and optimizing what one can do than what one cannot do and emphasizes the individual's agency over changing what they are able to change. Wellness is therefore not a passive state but rather an active goal to be sought continually. When viewed in this fashion, wellness is accessible to all. The conference addressed multiple aspects of wellness and embraced this philosophy throughout.

Obesity-Associated Differentially Methylated Regions in Colon Cancer

Obesity with adiposity is a common disorder in modern days, influenced by environmental factors such as eating and lifestyle habits and affecting the epigenetics of adipose-based gene regulations and metabolic pathways in colorectal cancer (CRC). We compared epigenetic changes of differentially methylated regions (DMR) of genes in colon tissues of 225 colon cancer cases (154 non-obese and 71 obese) and 15 healthy non-obese controls by accessing The Cancer Genome Atlas (TCGA) data. We applied machine-learning-based analytics including generalized regression (GR) as a confirmatory validation model to identify the factors that could contribute to DMRs impacting colon cancer to enhance prediction accuracy. We found that age was a significant predictor in obese cancer patients, both alone (p = 0.003) and interacting with hypomethylated DMRs of ZBTB46, a tumor suppressor gene (p = 0.008). DMRs of three additional genes: HIST1H3I (p = 0.001), an oncogene with a hypomethylated DMR in the promoter region; SRGAP2C (p = 0.006), a tumor suppressor gene with a hypermethylated DMR in the promoter region; and NFATC4 (p = 0.006), an adipocyte differentiating oncogene with a hypermethylated DMR in an intron region, are also significant predictors of cancer in obese patients, independent of age. The genes affected by these DMR could be potential novel biomarkers of colon cancer in obese patients for cancer prevention and progression.

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.

Obesity, colorectal cancer and MACC1 expression: A possible novel molecular association

Obesity is a major and increasing public health concern, associated with an increased risk of and mortality from several types of cancer including colorectal cancer (CRC), being associated with cancer progression, metastasis and resistance to therapy. It was hypothesized that the expression of cancer/metastasis-inducing gene metastasis-associated in colon cancer 1 (MACC1) is increased in obesity, which may constitute a link to obesity-induced cancer. The present study thus analyzed circulating cell-free plasma MACC1 expression levels in human obese (vs. normal weight) adult individuals from independent studies, namely the Martin Luther University (MLU) study (n=32) and the Metabolic syndrome study (MetScan, Berlin) (n=191). Higher plasma MACC1 levels were found in obese individuals, increasing with a greater body fat mass and body mass index; these levels were predominantly observed in male and to a lesser extent in female individuals, although the results were not significant. A reduction in body fat mass following dietary intervention and physical exercise decreased the MACC1 expression levels in the MLU study. Furthermore, Wistar rats with diet-induced obesity exhibited slightly increased plasma MACC1 levels compared with rats of normal weight. The obese Wistar rats exposed to azoxymethane to induce colon cancer exhibited a more severe colon tumor outcome, which was associated with significantly increased MACC1 levels compared with their non-obese littermates. On the whole, the findings of the present study suggest an association between MACC1 and obesity, as well as with obesity-induced CRC.

Bariatric surgery in patients with breast and endometrial cancer in California: population-based prevalence and survival

BACKGROUND

The number of bariatric surgeries performed in the United States has increased substantially since the 1990's. However, the prevalence and prognostic impact of bariatric surgery, or weight loss surgery (WLS), among patients with cancer are not known.

OBJECTIVES

We investigated the population-based prevalence of WLS in women with breast or endometrial cancer and conducted exploratory analysis to examine whether postdiagnosis WLS is associated with survival.

SETTING

Administrative statewide database.

METHODS

WLS records for women with nonmetastasized breast (n = 395,146) or endometrial (n = 69,859) cancer were identified from the 1991-2014 California Cancer Registry data linked with the California Office of Statewide Health Planning and Development database. Characteristics of the patients were examined according to history of WLS. Using body mass index data available since 2011, a retrospective cohort of patients with breast or endometrial cancer and obesity (n = 12,540) was established and followed until 2017 (5% lost to follow-up). Multivariable cause-specific Cox proportional hazards models were used to examine the associations between postdiagnostic WLS and time to death.

RESULTS

WLS records were identified for 2844 (.7%) patients with breast cancer and 1140 (1.6%) patients with endometrial cancer; about half of the surgeries were performed after cancer diagnosis. Postdiagnosis WLS was performed in ∼1% of patients with obesity and was associated with a decreased hazard for death (cause-specific hazard ratio = .37; 95% confidence interval = .014-.99; P = .049), adjusting for age, stage, co-morbidity, race/ethnicity, and socioeconomic status.

CONCLUSION

About 2000 patients with breast or endometrial cancer in California underwent post-diagnosis WLS between 1991 and 2014. Our data support survival benefits of WLS after breast and endometrial cancer diagnosis.

A review of research on the intersection between breast cancer and cardiovascular research in the Women's Health Initiative (WHI)

Both obesity and metabolic syndrome are linked to increased incidence of type 2 diabetes, cardiovascular disease (CVD), and cancers of the breast (post-menopausal), and other obesity-related cancers. Over the past 50 years, the worldwide prevalence of obesity and metabolic syndrome has increased, with a concomitant higher incidence of associated co-morbidities and mortality. The precise mechanism linking metabolic syndrome to increased cancer incidence is incompletely understood, however, individual components of metabolic syndrome have been linked to increased breast cancer incidence and worse survival. There is a bidirectional relationship between the risk of CVD and cancer due to a high burden of shared risk factors and higher rates of CVD among cancer survivors, which may be impacted by the pro-inflammatory microenvironment associated with metabolic syndrome and cancer-directed therapies. The Women's Health Initiative (WHI) is an excellent resource to study a dual relationship between cancer and CVD (cardio-oncology) with extensive information on risk factors and long-term outcomes. The purpose of this review is to provide an overview of research on cardio-oncology conducted utilizing WHI data with focus on studies evaluating both breast cancer and CVD including shared risk factors and outcomes after cancer. The review also includes results on other obesity related cancers which were included in the analyses of breast cancer, articles looking at cancer after heart disease (reverse cardio-oncology) and the role of Clonal Hematopoiesis of Indeterminate Potential (CHIP) as a shared risk factor between CVD and cancer. A summary of pertinent WHI literature helps to delineate the direction of future research evaluating the relationship between CVD and other cancer sites, and provides information on the opportunity for other novel analyses within the WHI.

Nonalcoholic fatty liver disease is specifically related to the risk of hepatocellular cancer but not extrahepatic malignancies

OBJECTIVE

We performed a matched cohort study among individuals with and without nonalcoholic fatty liver disease (NAFLD) to determine: 1) the incidence of cancers (extrahepatic and liver) and their spectrum and 2) if NAFLD increases the risk of extrahepatic cancers.

METHODS

The NAFLD and non-NAFLD (control) cohorts were identified from electronic medical records via International Classification of Diseases (ICD) codes from a single center and followed from 2010 to 2019. Cohorts were matched 1:2 for age, sex, race, body mass index (BMI), and type 2 diabetes.

RESULTS

A total of 1,412 subjects were included in the analyses. There were 477 individuals with NAFLD and 935 controls (median age, 52 years; women, 54%; white vs. black: 59% vs. 38%; median BMI, 30.4 kg/m²; type 2 diabetes, 34%). The cancer incidence (per 100,000 person-years) was 535 vs. 1,513 (NAFLD vs. control). Liver cancer incidence (per 100,000 person-years) was 89 in the NAFLD group vs. 0 in the control group, whereas the incidence of malignancy was higher across other types of cancer in the control group vs. in the NAFLD group.

CONCLUSIONS

The overall extrahepatic cancer risk in NAFLD is not increased above and beyond the risk from background risk factors such as age, race, sex, BMI, and type 2 diabetes.

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

•

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

•

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.

Obesity, metabolic syndrome, and cancer: pathophysiological and therapeutic associations

Overweight, obesity, and metabolic syndrome (MetS) have become epidemic conditions affecting 39%, 13%, and 20% of the population respectively. The aim of this article is to review the literature on the association of obesity and MetS with the risk of cancer. We also explore the effect of lifestyle modifications, such as diet, physical activity, and antidiabetic medications, on cancer incidence. Increased body mass index (BMI) has been associated with a multitude of site-specific cancers, reaching relative risk (RR) 1.54 [95% confidence interval (CI) 1.47-1.61] per 5 unit increase for endometrial cancer, as well as with overall cancer risk (RR 1.03, 95% CI 1.02-1.05). Central adiposity measured by waist circumference or waist-to-hip ratio has been suggested as a stronger predictor than BMI for several cancers, such as colorectal cancer. Metabolic Syndrome has been consistently and positively associated with the risk of very common cancers like colorectal (RR 1.34, 95% CI 1.24-1.44), endometrial (RR 1.62, 95% CI 1.26-2.07) and postmenopausal breast cancer (RR 2.01, 95% CI 1.55-2.60). Hyperglycemia and subsequently T2DM have been also shown to increase the risk of cancer. Nevertheless, these risk factors are modifiable and therefore implementing lifestyle modifications could prevent an important number of cancer cases. Adherence to cancer prevention guidelines, including maintaining a healthy weight, having regular physical exercise (RR 0.58-0.90 for different cite specific cancers) and following a healthy dietary pattern (RR 0.74-0.94 for different cite specific cancers) have a protective effect on the risk of cancer. The strength of this review is the presentation of the best evidence, as the data derive mainly from meta-analyses. Public health policies should focus on the modification of risk factors and future research is needed to reveal the pathophysiological links between these risk factors and cancer to develop more efficient prevention and treatment strategies.

Spot-light on microbiota in obesity and cancer

Over the last few years, the complexity and diversity of gut microbiota within and across individuals has been detailed in relation to human health. Further, understanding of the bidirectional association between gut microbiota and metabolic disorders has highlighted a complimentary, yet crucial role for microbiota in the onset and progression of obesity-related cancers. While strategies for cancer prevention and cure are known to work efficiently when supported by healthy diet and lifestyle choices and physical activity, emerging evidence suggests that the complex interplay relating microbiota both to neoplastic and metabolic diseases could aid strategies for cancer treatment and outcomes. This review will explore the experimental and clinical grounds supporting the functional role of gut microbiota in the pathophysiology and progression of cancers in relation to obesity and its metabolic correlates. Therapeutic approaches aiding microbiota restoration in connection with cancer treatments will be discussed.

The Troubling Link Between Non-alcoholic Fatty Liver Disease (NAFLD) and Extrahepatic Cancers (EHC)

Non-alcoholic fatty liver disease (NAFLD) is a fast-spreading epidemic across the globe and has serious implications far beyond that of a "benign" liver condition. It is usually an outcome of ectopic fat storage due to chronic positive energy balance leading to obesity and is associated with multiple health problems. While association with cardiovascular disease and hepatocellular cancer is well recognized, it is becoming clear the NAFLD carries with it an increased risk of cancers of extrahepatic tissues. Studies have reported a higher risk for cancers of the colon, breast, prostate, lung, and pancreas. Fatty liver is associated with increased mortality; there is an urgent need to understand that fatty liver is not always benign, and not always associated with obesity. It is, however, a reversible condition and early recognition and intervention can alter its natural history and associated complications.

Adiposity, Adulthood Weight Change and Risk of Incident Hepatocellular Carcinoma

Prospective data are limited regarding dynamic adulthood weight changes and hepatocellular carcinoma (HCC) risk. We included 77,238 women (1980-2012) and 48,026 men (1986-2012), who recalled young-adult weight (age 18 years [women]; 21 years [men]), and provided biennially-updated information regarding weight, body mass index (BMI) and comorbidities. Overall adulthood weight change was defined as the difference in weight (kilograms) between young-adulthood and present. Using Cox proportional hazards models, we calculated multivariable-adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs). Over 3,676,549 person-years, we documented 158 incident HCC cases. Elevated HCC risk was observed with higher BMI in both young-adulthood and later-adulthood (continuous aHRs per each 1-unit=1.05, 95%CI=1.02-1.09 [Ptrend=0.019], and 1.08, 95%CI=1.06-1.10 [Ptrend=0.004], respectively). Moreover, overall adulthood weight gain was also significantly associated with increased HCC risk (aHR per each 1-kg increase=1.03, 95%CI=1.01-1.08; Ptrend=0.010), including after further adjusting for young-adult BMI (Ptrend=0.010) and later-adult BMI (Ptrend=0.008). Compared to adults with stable weight (+/-5kg), the multivariable-aHRs with weight gain of 5-<10kg, 10-<20kg and {greater than or equal to}20kg were, 1.40 (95%CI=0.67-2.16), 2.09 (95%CI=1.11-3.95) and 2.61 (95%CI=1.42-5.22), respectively. In two prospective, nationwide cohorts, adulthood weight gain was significantly associated with increased HCC risk.

Obesity-related Cancers: The Coming Epidemic

The world is in the grip of an obesity pandemic, with tripling of obesity rates since 1975; it is predicted that one-third of people on Earth will be obese by 2025. The health consequences of obesity are primarily thought to be related to cardiometabolic disorders such as diabetes and cardiovascular diseases. It is less well appreciated that obesity has been related to at least 13 different cancers and in future, (with increasing control over tobacco misuse and infections), obesity will be the main cause of cancers. While this is an area of active research, there are large gaps in the definition of what is an obesity related cancer (JRC) and more importantly, what are the underlying mechanisms. To an extent, this is due to the controversy on what constitutes “unhealthy obesity” which is further related to the causes of obesity. This narrative review examines the causes and measurement of obesity, the types of obesity-related cancers and possible mechanisms. The information has wide implications ranging from prevention, screening, prognosis and therapeutic strategies. Obesity related cancers should be an area of high-priority research. Oncologists can contribute by spreading awareness and instituting management measures for individual patients in their care.

Visceral Adiposity and Cancer: Role in Pathogenesis and Prognosis

The prevalence of being overweight and obese has been expanded dramatically in recent years worldwide. Obesity usually occurs when the energetic introit overtakes energy expenditure from metabolic and physical activity, leading to fat accumulation mainly in the visceral depots. Excessive fat accumulation represents a risk factor for many chronic diseases, including cancer. Adiposity, chronic low-grade inflammation, and hyperinsulinemia are essential factors of obesity that also play a crucial role in tumor onset. In recent years, several strategies have been pointed toward boundary fat accumulation, thus limiting the burden of cancer attributable to obesity. While remodeling fat via adipocytes browning seems a tempting prospect, lifestyle interventions still represent the main pathway to prevent cancer and enhance the efficacy of treatments. Specifically, the Mediterranean Diet stands out as one of the best dietary approaches to curtail visceral adiposity and, therefore, cancer risk. In this Review, the close relationship between obesity and cancer has been investigated, highlighting the biological mechanisms at the basis of this link. Finally, strategies to remodel fat, including browning and lifestyle interventions, have been taken into consideration as a major perspective to limit excess body weight and tumor onset.

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.

The Triple Health Threat of Diabetes, Obesity, and Cancer-Epidemiology, Disparities, Mechanisms, and Interventions

Obesity and type 2 diabetes are both chronic, relapsing, progressive diseases that are recognized as risk factors for the development of multiple types of cancer. In a recent symposium titled "Hitting A Triple-Diabetes, Obesity, and the Emerging Links to Cancer Risk," convened by The Obesity Society during ObesityWeek 2019, experts in the field presented the current science and highlighted existing research gaps. Topics included (1) the epidemiology of obesity and diabetes and their links to cancer risk; (2) racial and ethnic differences in obesity, diabetes, and cancer risk; (3) biological mechanisms common to obesity and diabetes that may increase cancer risk; and (4) innovative interventions that can be used to prevent the development of cancers related to obesity and diabetes. This report provides an overview of the symposium and describes key research gaps and pressing questions in need of answers to advance the field. The collective burden of obesity, diabetes, and cancer represents one of the largest public health challenges of the century. Although the symposium was titled "hitting a triple," it was recognized that being able to disrupt the linkages among obesity, diabetes, and cancer would be a "grand slam" for public health and medicine.