Obesity and Cancer: Insights for Clinicians

Early-onset and later-onset cancer: trends, risk factors, and prevention in Northern China

The characteristics of early-onset (onset age <50 years) and later-onset (onset age ≽ 50 years) cancers differ significantly. Identifying novel risk factors for both types of cancer is crucial for increasing awareness of cancer prevention and for reducing its burden. This study aimed to analyze the trends in incidence and risk factors for early-onset and late-onset cancers. We conducted a prospective study by drawing data from the Kailuan Study. This study included 6,741 participants with cancer (624 with early-onset cancer and 6,117 with later-onset cancer) and 6,780 matched controls among the 186,249 participants who underwent Kailuan health examinations from 2006 to 2019. The primary outcomes were cancer incidence rates, and associated risk factors for early- and later-onset cancer. Weighted Cox regression was used to calculate hazard ratios and 95% confidence intervals of each exposure factor for early- and later-onset cancer by cancer type. Population-attributable risk proportions were used to estimate the number of cases that could be prevented by eliminating a risk factor from the population. Except for liver cancer, incidence rates for nearly all types of cancer increased during the study period. Smoking, alcohol consumption, lipid metabolism disorders, hypertension, diabetes mellitus, fatty liver, and inflammation were associated with a significantly increased risk of cancer at multiple sites, but risk factors for cancer incidence differed by site. Smoking, alcohol consumption, inflammation, and hypertension were the major contributors to preventable cancer. The incidence of several different types of cancer, including early-onset cancer, is increasing in northeastern China. Differences in risk factors between early-onset and later-onset malignancies may contribute to the divergence in the observed changes in incidence trends between these two specific types of cancer.

Shared Lifestyle-Related Risk Factors of Cardiovascular Disease and Cancer: Evidence for Joint Prevention

Cardiovascular disease (CVD) and cancer are leading causes of mortality and morbidity worldwide and are the major focus of the World Health Organization's joint prevention programs. While, diverse diseases, CVD and cancer, have many similarities. These include common lifestyle-related risk factors and shared environmental, metabolic, cellular, inflammatory, and genetic pathways. In this review, we will discuss the shared lifestyle-related and environmental risk factors central to both diseases and how the strategies commonly used to prevent atherosclerotic vascular disease can be applied to cancer prevention.

Obesity Measured via Body Mass Index May Be Associated with Increased Incidence but Not Worse Outcomes of Immune-Mediated Diarrhea and Colitis

Obesity defined by high body mass index (BMI) has traditionally been associated with gastrointestinal inflammatory processes but has recently been correlated with better survival in patients receiving immune checkpoint inhibitors (ICI). We sought to investigate the association between BMI and immune-mediated diarrhea and colitis (IMDC) outcomes and whether BMI reflects body fat content on abdominal imaging. This retrospective, single-center study included cancer patients with ICI exposure who developed IMDC and had BMI and abdominal computed tomography (CT) obtained within 30 days before initiating ICI from April 2011 to December 2019. BMI was categorized as <25, ≥25 but <30, and ≥30. Visceral fat area (VFA), subcutaneous fat area (SFA), total fat area (TFA: VFA+SFA), and visceral to subcutaneous fat (V/S) ratio were obtained from CT at the umbilical level. Our sample comprised 202 patients; 127 patients (62.9%) received CTLA-4 monotherapy or a combination, and 75 (37.1%) received PD-1/PD-L1 monotherapy. Higher BMIs ≥ 30 were associated with a higher incidence of IMDC than BMIs ≤ 25 (11.4% vs. 7.9%, respectively; p = 0.029). Higher grades of colitis (grade 3-4) correlated with lower BMI (p = 0.03). BMI level was not associated with other IMDC characteristics or did not influence overall survival (p = 0.83). BMI is strongly correlated with VFA, SFA, and TFA (p < 0.0001). Higher BMI at ICI initiation was linked to a higher incidence of IMDC but did not appear to affect outcomes. BMI strongly correlated with body fat parameters measured by abdominal imaging, suggesting its reliability as an obesity index.

Therapeutic Potential of Tumor Metabolic Reprogramming in Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) is the most aggressive subtype of breast cancer, with clinical features of high metastatic potential, susceptibility to relapse, and poor prognosis. TNBC lacks the expression of the estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2). It is characterized by genomic and transcriptional heterogeneity and a tumor microenvironment (TME) with the presence of high levels of stromal tumor-infiltrating lymphocytes (TILs), immunogenicity, and an important immunosuppressive landscape. Recent evidence suggests that metabolic changes in the TME play a key role in molding tumor development by impacting the stromal and immune cell fractions, TME composition, and activation. Hence, a complex inter-talk between metabolic and TME signaling in TNBC exists, highlighting the possibility of uncovering and investigating novel therapeutic targets. A better understanding of the interaction between the TME and tumor cells, and the underlying molecular mechanisms of cell-cell communication signaling, may uncover additional targets for better therapeutic strategies in TNBC treatment. In this review, we aim to discuss the mechanisms in tumor metabolic reprogramming, linking these changes to potential targetable molecular mechanisms to generate new, physical science-inspired clinical translational insights for the cure of TNBC.

Gut Microbiota, Metabolic Disorders and Breast Cancer: Could Berberine Turn Out to Be a Transversal Nutraceutical Tool? A Narrative Analysis

Metabolic disorders, mainly characterized as the marked alteration of the lipid and carbohydrate profile, in addition to the clinical presence of the direct consequences of these alterations, are pathological conditions that have considerably increased in prevalence in recent years. They are directly linked to the onset of various pathologies, including cancer, particularly breast cancer, and are hormone-responsive. Alongside the known conditions responsible for this scenario, such as nutrition and lifestyle in general, the importance of both the colonic microbiota and the various organs and systems is becoming increasingly evident. In fact, it is now evident that microbial dysbiosis plays a fundamental role in the onset of these metabolic disorders, and therefore how these conditions are indirectly responsible for the onset and progression of neoplasms. Indirect mechanisms such as an altered Firmicutes/Bacteroidetes ratio; the formation of metabolites such as short-chain fatty acids (SCFAs), in particular, butyrate, which is capable of acting as a tumor suppressor; and the glucuronidase activity of estroboloma (bacteria responsible for estrogen metabolism) are just some of the most important mechanisms that contribute to the history of breast cancer. It is therefore understandable that in clinical terms, it is essential to associate the modulation of metabolic disorders and the microbial conditions that contribute to generating them with common therapies, preferably using compounds and solutions that are effective and acceptable for the patient without side effects. Nutraceuticals such as berberine (active both in metabolic scenarios and in the microbiota) and interventions modulating the microbial structure such as the use of probiotics and prebiotics seem to be ideal solutions for these preventive and no-longer-ignorable strategies in the light of numerous data now present in the literature.

Ketogenic diets, physical activity and body composition: a review

Obesity remains a serious relevant public health concern throughout the world despite related countermeasures being well understood (i.e. mainly physical activity and an adjusted diet). Among different nutritional approaches, there is a growing interest in ketogenic diets (KD) to manipulate body mass (BM) and to enhance fat mass loss. KD reduce the daily amount of carbohydrate intake drastically. This results in increased fatty acid utilisation, leading to an increase in blood ketone bodies (acetoacetate, 3-β-hydroxybutyrate and acetone) and therefore metabolic ketosis. For many years, nutritional intervention studies have focused on reducing dietary fat with little or conflicting positive results over the long term. Moreover, current nutritional guidelines for athletes propose carbohydrate-based diets to augment muscular adaptations. This review discusses the physiological basis of KD and their effects on BM reduction and body composition improvements in sedentary individuals combined with different types of exercise (resistance training or endurance training) in individuals with obesity and athletes. Ultimately, we discuss the strengths and the weaknesses of these nutritional interventions together with precautionary measures that should be observed in both individuals with obesity and athletic populations. A literature search from 1921 to April 2021 using Medline, Google Scholar, PubMed, Web of Science, Scopus and Sportdiscus Databases was used to identify relevant studies. In summary, based on the current evidence, KD are an efficient method to reduce BM and body fat in both individuals with obesity and athletes. However, these positive impacts are mainly because of the appetite suppressive effects of KD, which can decrease daily energy intake. Therefore, KD do not have any superior benefits to non-KD in BM and body fat loss in individuals with obesity and athletic populations in an isoenergetic situation. In sedentary individuals with obesity, it seems that fat-free mass (FFM) changes appear to be as great, if not greater, than decreases following a low-fat diet. In terms of lean mass, it seems that following a KD can cause FFM loss in resistance-trained individuals. In contrast, the FFM-preserving effects of KD are more efficient in endurance-trained compared with resistance-trained individuals.

Awareness of link between obesity and breast cancer risk is associated with willingness to participate in weight loss intervention

PURPOSE

To assess knowledge of obesity-associated cancer risk, self-awareness of BMI status, and willingness to engage in weight loss intervention in breast cancer survivors with overweight and obesity as a companion study for a novel weight loss program using a telehealth platform (NCT04855552).

METHODS

Breast cancer survivors with BMI ≥ 25 kg/m² were surveyed to assess self-perception of BMI, knowledge of obesity-related cancer risk, and willingness to participate in weight loss programs. Multivariable logistic regression was used to assess factors associated with willingness to participate.

RESULTS

Of the 122 participants, 73 (59.8%) had BMI 25.0-29.9 kg/m² (overweight) and 49 (40.2%) had BMI ≥ 30 (obesity). Patients with obesity were more likely to underestimate their BMI than those with overweight, 40.8% vs. 23.3% (p = 0.03). The majority (82.0%) indicated awareness that obesity increases breast cancer risk and 57.4% expressed interest in a weight loss program. Patients with knowledge of obesity-related breast cancer risk (91.4% willing vs. 69.2% not willing, p < 0.01) were more willing to participate in a weight loss program on univariable and multivariable analyses (p < 0.01).

CONCLUSION

Our results underscore the importance of raising patients' awareness of obesity-related health risks and individual BMI category. Future work in the development of better education and communication tools to improve awareness will likely improve the adoption rate of healthy lifestyles in at-risk patients.

Trends in Incidence and Mortality Rates of Uterine Cancer in Kentucky

OBJECTIVES

The objective of this analysis was to gauge how the incidence and mortality of uterine cancer in Kentucky have changed from 1995 through 2017. An assessment of the trends in incidence and mortality across different geographic areas and between different races was also performed.

METHODS

Age-adjusted annual incidence and mortality rates for uterine cancer were obtained from the Kentucky Cancer Registry. A meta-regression framework was used to assess changes in incidence and mortality rates during the time frame and to determine differences in these rates between rural versus urban counties, Appalachian versus non-Appalachian counties, and Black versus White women.

RESULTS

The incidence of uterine cancer has significantly increased throughout the state of Kentucky since 1995. Uterine cancer incidence was 10% and 22% higher in rural and Appalachian counties, respectively, compared with urban and non-Appalachian counties (P < 0.0001) from 1995 through 2017. In contrast, urban and non-Appalachian women had higher or equivalent age-adjusted mortality from uterine cancer, compared with rural and Appalachian women, respectively. The incidence of uterine cancer was significantly higher in White women compared with Black women from 1995 through 2006, but since 2007, there has been no significant difference in uterine cancer incidence based on race. Black women had higher age-adjusted mortality than White women throughout the entire time period examined.

CONCLUSIONS

The incidence of uterine cancer is higher in rural and Appalachian Kentucky, without a corresponding geographic trend in mortality. Uterine cancer mortality is significantly higher in Black women.

Dual-energy three-compartment breast imaging for compositional biomarkers to improve detection of malignant lesions

Background

While breast imaging such as full-field digital mammography and digital breast tomosynthesis have helped to reduced breast cancer mortality, issues with low specificity exist resulting in unnecessary biopsies. The fundamental information used in diagnostic decisions are primarily based in lesion morphology. We explore a dual-energy compositional breast imaging technique known as three-compartment breast (3CB) to show how the addition of compositional information improves malignancy detection.

Methods

Women who presented with Breast Imaging-Reporting and Data System (BI-RADS) diagnostic categories 4 or 5 and who were scheduled for breast biopsies were consecutively recruited for both standard mammography and 3CB imaging. Computer-aided detection (CAD) software was used to assign a morphology-based prediction of malignancy for all biopsied lesions. Compositional signatures for all lesions were calculated using 3CB imaging and a neural network evaluated CAD predictions with composition to predict a new probability of malignancy. CAD and neural network predictions were compared to the biopsy pathology.

Results

The addition of 3CB compositional information to CAD improves malignancy predictions resulting in an area under the receiver operating characteristic curve (AUC) of 0.81 (confidence interval (CI) of 0.74-0.88) on a held-out test set, while CAD software alone achieves an AUC of 0.69 (CI 0.60-0.78). We also identify that invasive breast cancers have a unique compositional signature characterized by reduced lipid content and increased water and protein content when compared to surrounding tissues.

Conclusion

Clinically, 3CB may potentially provide increased accuracy in predicting malignancy and a feasible avenue to explore compositional breast imaging biomarkers.

An update on pharmacotherapeutic strategies for obesity

INTRODUCTION

The field of obesity medicine has evolved over the past several years. With greater understanding of its pathophysiology, obesity is regarded more as a chronic disease than a lifestyle choice. However, it is difficult to treat with lifestyle modifications alone due to the complexity of energy dysregulation. The availability of anti-obesity medications (AOMs) provides practitioners with more effective and sustainable ways to treat obesity.

AREAS COVERED

This review briefly summarizes the weight loss efficacy of AOMs currently approved for long-term use and expands on their therapeutic potential beyond weight loss with particular focus on obesity-related comorbidities. Possible future AOMs with promising phase II or III data are also covered.

EXPERT OPINION

The future of obesity medicine is in recognizing obesity as a disease and approaching treatment similarly to other chronic diseases. Lifestyle interventions alone are rarely sufficient in the treatment of chronic diseases, and pharmacotherapy often plays a necessary role in changing the course of disease. Current AOMs have proven efficacy in weight management and emerging therapeutic uses in obesity-related comorbidities, such as non-alcoholic fatty liver disease, obstructive sleep apnea, and polycystic ovarian syndrome. The development of new AOMs will further empower providers to deliver effective obesity management.

Impact of Obesity on Quality of Life, Psychological Distress, and Coping on Patients with Colon Cancer

BACKGROUND

Despite the causal relationship between obesity and colon cancer being firmly established, the effect of obesity on the course of cancer calls for further elucidation. The objective of this study was to assess differences in clinical-pathological and psychosocial variables between obese and nonobese individuals with colon cancer.

MATERIALS AND METHODS

This was a prospective, multicentric, observational study conducted from 2015-2018. The sample comprised patients with stage II-III, resected colon cancer about to initiate adjuvant chemotherapy with fluoropyrimidine in monotherapy or associated with oxaliplatin and grouped into nonobese (body mass index <30 kg/m² ) or obese (≥30 kg/m² ). Subjects completed questionnaires appraising quality of life (European Organization for Research and Treatment of Cancer Quality of Life Core questionnaire), coping (Mini-Mental Adjustment to Cancer), psychological distress (Brief Symptom Inventory 18), perceived social support (Multidimensional Scale of Perceived Social Support), personality (Big Five Inventory 10), and pain (Brief Pain Inventory). Toxicity, chemotherapy compliance, 12-month recurrence, and mortality rate data were recorded.

RESULTS

Seventy-nine of the 402 individuals recruited (19.7%) were obese. Obese subjects exhibited more comorbidities (≥2 comorbidities, 46.8% vs. 30.3%, p = .001) and expressed feeling slightly more postoperative pain (small size-effect). There was more depression, greater helplessness, less perceived social support from friends, and greater extraversion among the obese versus nonobese subjects (all p < .04). The nonobese group treated with fluoropyrimidine and oxaliplatin suffered more grade 3-4 hematological toxicity (p = .035), whereas the obese had higher rates of treatment withdrawal (17.7% vs. 7.7%, p = .033) and more recurrences (10.1% vs. 3.7%, p = .025). No differences in sociodemographic, quality of life, or 12-month survival variables were detected.

CONCLUSION

Obesity appears to affect how people confront cancer, as well as their tolerance to oncological treatment and relapse.

IMPLICATIONS FOR PRACTICE

Obesity is a causal factor and affects prognosis in colorectal cancer. Obese patients displayed more comorbidities, more pain after cancer surgery, worse coping, and more depression and perceived less social support than nonobese patients. Severe hematological toxicity was more frequent among nonobese patients, whereas rates of withdrawal from adjuvant chemotherapy were higher in the obese cohort, and during follow-up, obese patients presented greater 12-month recurrence rates. With the growing and maintained increase of obesity and the cancers associated with it, including colorectal cancer, the approach to these more fragile cases that have a worse prognosis must be adapted to improve outcomes.

Optimising weight-loss interventions in cancer patients-A systematic review and network meta-analysis

Background

Excess weight has been associated with increased morbidity and a worse prognosis in adult patients with early-stage cancer. The optimal lifestyle interventions to optimize anthropometric measures amongst cancer patients and survivors remain inconsistent.

Objective

To conduct a systematic review and network meta-analysis (NMA) of randomized controlled trials (RCTs) comparing the effects of exercise and dietary interventions alone or in combination on anthropometric measures of adult cancer patients and survivors.

Methods

A systematic search of Medline, Embase and the Cochrane Trials Registry was performed. Outcomes of interest included changes in weight, body mass index (BMI), and waist circumference. Screening and data collection were performed by two reviewers. Bayesian NMAs were performed.

Results

Overall, 98 RCTs were included; 75 were incorporated in NMAs (n = 12,199). Groups of intervention strategies included: 3 exercise interventions, 8 dietary interventions, 7 combination interventions of diet and exercise and standard care. Median intervention duration was 26 weeks. NMA suggested that diet alone (mean difference [MD] -2.25kg, 95% CrI -3.43 to -0.91kg) and combination strategies (MD -2.52kg, 95% CrI -3.54 to -1.62kg) were associated with more weight loss compared to standard care. All dietary interventions achieved a similar magnitude of weight loss (MD range from -2.03kg to -2.52kg). Both diet alone and combination strategies demonstrated greater BMI reductions versus standard care, and each of diet alone, exercise alone and combination strategies demonstrated greater reductions in waist circumference than standard care.

Conclusion

Diet and exercise alone or in combination are effective lifestyle interventions to improve anthropometric measures in cancer patients and survivors. All reputable diets appear to be similarly effective to achieve weight loss.

Tumor organoid models in precision medicine and investigating cancer-stromal interactions

Tumor development and progression require chemical and mechanical cues derived from cellular and non-cellular components in the tumor microenvironment, including the extracellular matrix (ECM), cancer-associated fibroblasts (CAFs), endothelial cells, and immune cells. Therefore, it is crucial to develop tissue culture models that can mimic in vivo cancer cell-ECM and cancer-stromal cell interactions. Three-dimensional (3D) tumor culture models have been widely utilized to study cancer development and progression. A recent advance in 3D culture is the development of patient-derived tumor organoid (PDO) models from primary human cancer tissue. PDOs maintain the heterogeneity of the primary tumor, which makes them more relevant for identifying therapeutic targets and verifying drug response. Other significant advances include development of 3D co-culture assays to investigate cell-cell interactions and tissue/organ morphogenesis, and microfluidic technology that can be integrated into 3D culture to mimic vasculature and blood flow. These advances offer spatial and temporal insights into cancer cell-stromal interactions and represent novel techniques to study tumor progression and drug response. Here, we summarize the recent progress in 3D culture and tumor organoid models, and discuss future directions and the potential of utilizing these models to study cancer-stromal interactions and direct personalized treatment.

High-Fat Diet Accelerates Carcinogenesis in a Mouse Model of Barrett's Esophagus via Interleukin 8 and Alterations to the Gut Microbiome

BACKGROUND & AIMS

Barrett's esophagus (BE) is a precursor to esophageal adenocarcinoma (EAC). Progression from BE to cancer is associated with obesity, possibly due to increased abdominal pressure and gastroesophageal reflux disease, although this pathogenic mechanism has not been proven. We investigated whether environmental or dietary factors associated with obesity contribute to the progression of BE to EAC in mice.

METHODS

Tg(ED-L2-IL1RN/IL1B)#Tcw mice (a model of BE, called L2-IL1B mice) were fed a chow (control) or high-fat diet (HFD) or were crossbred with mice that express human interleukin (IL) 8 (L2-IL1B/IL8 mice). Esophageal tissues were collected and analyzed for gene expression profiles and by quantitative polymerase chain reaction, immunohistochemistry, and flow cytometry. Organoids were established from BE tissue of mice and cultured with serum from lean or obese individuals or with neutrophils from L2-IL1B mice. Feces from mice were analyzed by 16s ribosomal RNA sequencing and compared to 16s sequencing data from patients with dysplasia or BE. L2-IL1B were mice raised in germ-free conditions.

RESULTS

L2-IL1B mice fed an HFD developed esophageal dysplasia and tumors more rapidly than mice fed the control diet; the speed of tumor development was independent of body weight. The acceleration of dysplasia by the HFD in the L2-IL1B mice was associated with a shift in the gut microbiota and an increased ratio of neutrophils to natural killer cells in esophageal tissues compared with mice fed a control diet. We observed similar differences in the microbiomes from patients with BE that progressed to EAC vs patients with BE that did not develop into cancer. Tissues from dysplasias of L2-IL1B mice fed the HFD contained increased levels of cytokines that are produced in response to CXCL1 (the functional mouse homolog of IL8, also called KC). Serum from obese patients caused organoids from L2-IL1B/IL8 mice to produce IL8. BE tissues from L2-IL1B mice fed the HFD and from L2-IL1B/IL8 mice contained increased numbers of myeloid cells and cells expressing Cxcr2 and Lgr5 messenger RNAs (epithelial progenitors) compared with mice fed control diets. BE tissues from L2-IL1B mice raised in germ-free housing had fewer progenitor cells and developed less dysplasia than in L2-IL1 mice raised under standard conditions; exposure of fecal microbiota from L2-IL1B mice fed the HFD to L2-IL1B mice fed the control diet accelerated tumor development.

CONCLUSIONS

In a mouse model of BE, we found that an HFD promoted dysplasia by altering the esophageal microenvironment and gut microbiome, thereby inducing inflammation and stem cell expansion, independent of obesity.

Prehabilitation for adults diagnosed with cancer: A systematic review of long-term physical function, nutrition and patient-reported outcomes

OBJECTIVE

Prehabilitation is increasingly being used to mitigate treatment-related complications and enhance recovery. An individual's state of health at diagnosis, including obesity, physical fitness and comorbidities, are influencing factors for the occurrence of adverse effects. This review explores whether prehabilitation works in improving health outcomes at or beyond the initial 30 days post-treatment and considers the utility of prehabilitation before cancer treatment.

METHODS

A database search was conducted for articles published with prehabilitation as a pre-cancer treatment intervention between 2009 and 2017. Studies with no 30 days post-treatment data were excluded. Outcomes post-prehabilitation were extracted for physical function, nutrition and patient-reported outcomes.

RESULTS

Sixteen randomised controlled trials with a combined 2017 participants and six observational studies with 289 participants were included. Prehabilitation interventions provided multi-modality components including exercise, nutrition and psychoeducational aspects. Prehabilitation improved gait, cardiopulmonary function, urinary continence, lung function and mood 30 days post-treatment but was not consistent across studies.

CONCLUSION

When combined with rehabilitation, greater benefits were seen in 30-day gait and physical functioning compared to prehabilitation alone. Large-scale randomised studies are required to translate what is already known from feasibility studies to improve overall health and increase long-term cancer patient outcomes.

Causal effect of obesity on gynecologic malignancies

INTRODUCTION

Gynecologic malignancies are estimated to affect 110,070 women and will be the cause of death in approximately 32,120 in 2018. Endometrial cancer is among the most prevalent with 63,320 estimated new cases and approximately 11,350 deaths, followed by ovarian cancer with an estimate of 22,000 new cases and 14,000 deaths annually. Obesity is one of the most modifiable risk factors. Providers should engage in a multifaceted approach to patient education and healthcare to decrease the projected cases of obesity-related cancers.

BACKGROUND

The literature demonstrates a significant link between obesity and the development of certain malignancies such as endometrial, pancreatic, and renal cancer. Specific mechanisms found to play a role in the development of these malignancies include alterations of the metabolic pathway attributed to lipid accumulation as well as a chronic inflammatory process. Obesity also predisposes patients to other medical comorbidities as well as a poorer prognosis once a diagnosis of cancer is established. Factors contributing to poorer prognosis include challenges with treatment planning, specifically pertaining to inappropriate chemotherapy dosing and delivery of radiation therapy. Surgical approach and perioperative management are similarly challenging in obese patients and are associated with increased risk of complications.

CONCLUSION

Obesity is a modifiable factor which is associated with an increased risk of cancer and poorer outcomes. Providers should educate patients on all health hazards of obesity, including increased risk of cancer, and encourage them to participate in a structured weight loss plan.

The obesity paradox in cancer: clinical insights and perspectives

A series of evidence demonstrated that obesity represents an established risk factor for an increase in the incidence of multiple cancer types and for poor cancer survival. Nevertheless, recent studies suggested that, in a series of cancers, patients with a normal body mass index (BMI) have worse outcomes than obese patients. This phenomenon, named 'obesity paradox' or 'reverse epidemiology' in cancer, is not well understood and presents controversial aspects. Therefore, this review aims to explore the available studies concerning the relationship between obesity and cancer incidence or survival and to highlight the hypothetical explanations and the methodological framework. In this regard, we underline the limits of BMI as a potential marker of adiposity and the relevance to assessing body composition, beyond the body size. Further studies are needed to define the impact of obesity in cancer patients, to tailor weight management after cancer diagnosis and to hopefully improve overall clinical outcome.

Metabolic cooperation between cancer and non-cancerous stromal cells is pivotal in cancer progression

The way cancer cells adapt to microenvironment is crucial for the success of carcinogenesis, and metabolic fitness is essential for a cancer cell to survive and proliferate in a certain organ/tissue. The metabolic remodeling in a tumor niche is endured not only by cancer cells but also by non-cancerous cells that share the same microenvironment. For this reason, tumor cells and stromal cells constitute a complex network of signal and organic compound transfer that supports cellular viability and proliferation.

The intensive dual-address cooperation of all components of a tumor sustains disease progression and metastasis. Herein, we will detail the role of cancer-associated fibroblasts, cancer-associated adipocytes, and inflammatory cells, mainly monocytes/macrophages (tumor-associated macrophages), in the remodeling and metabolic adaptation of tumors.

Phase II prospective randomized trial of weight loss prior to radical prostatectomy

BACKGROUND

Obesity is associated with poorly differentiated and advanced prostate cancer and increased mortality. In preclinical models, caloric restriction delays prostate cancer progression and prolongs survival. We sought to determine if weight loss (WL) in men with prostate cancer prior to radical prostatectomy affects tumor apoptosis and proliferation, and if WL effects other metabolic biomarkers.

METHODS

In this Phase II prospective trial, overweight and obese men scheduled for radical prostatectomy were randomized to a 5–8 week WL program consisting of standard structured energy-restricted meal plans (1200–1500 Kcal/day) and physical activity or to a control group. The primary endpoint was apoptotic index in the radical prostatectomy malignant epithelium. Secondary endpoints were proliferation (Ki67) in the radical prostatectomy tissue, body weight, body mass index (BMI), waist to hip ratio, body composition, and serum PSA, insulin, triglyceride, cholesterol, testosterone, estradiol, leptin, adiponectin, interleukin 6, interleukin 8, insulin-like growth factor 1, and IGF binding protein 1.

RESULTS

Twenty-three patients were randomized to the WL intervention and twenty-one patients to the control group. Subjects in the intervention group had significantly more weight loss (WL:−3.7 ± 0.5 kg; Control:−1.6 ± 0.5 kg; p=0.007) than the control group and total fat mass was significantly reduced (WL:−2.1 ± 0.4; Control: 0.1 ± 0.3; p=0.015). There was no significant difference in apoptotic or proliferation index between the groups. Among the other biomarkers, triglyceride and insulin levels were significantly decreased in the WL compared to the control group.

CONCLUSIONS

In summary, this short-term WL program prior to radical prostatectomy resulted in significantly more WL in the intervention vs. the control group and was accompanied by significant reductions in body fat mass, circulating triglycerides, and insulin. However, no significant changes were observed in malignant epithelium apoptosis or proliferation. Future studies should consider a longer term or more intensive weight loss intervention.

Long-term weight loss after colorectal cancer diagnosis is associated with lower survival: The Colon Cancer Family Registry

BACKGROUND

Body weight is associated with colorectal cancer (CRC) risk and survival, but to the authors' knowledge, the impact of long-term postdiagnostic weight change is unclear. Herein, the authors investigated whether weight change over the 5 years after a diagnosis of CRC is associated with survival.

METHODS

CRC cases diagnosed from 1997 to 2008 were identified through 4 population-based cancer registry sites. Participants enrolled within 2 years of diagnosis and reported their height and weight 2 years prior. Follow-up questionnaires were administered approximately 5 years after diagnosis. Associations between change in weight (in kg) or body mass index (BMI) with overall and CRC-specific survival were estimated using Cox regression analysis adjusted for age, sex, American Joint Committee on Cancer stage of disease, baseline BMI, nonsteroidal anti-inflammatory drug use, smoking, time between diagnosis and enrollment, and study site.

RESULTS

At the 5-year postdiagnostic survey, 2049 participants reported higher (53%; median plus 5 kg), unchanged (12%), or lower (35%; median -4 kg) weight. Over a median of 5.1 years of subsequent follow-up (range, 0.3-9.9 years), 344 participants died (91 of CRC). Long-term weight loss (per 5 kg) was found to be associated with poorer overall survival (hazard ratio, 1.13; 95% confidence interval, 1.07-1.21) and CRC-specific survival (hazard ratio, 1.25; 95% confidence interval, 1.13-1.39). Significantly lower survival was similarly observed for relative weight loss (>5% vs ≤5% change), BMI reduction (per 1 unit), or BMI category change (overweight to normal vs remaining overweight).

CONCLUSIONS

Weight loss 5 years after a diagnosis of CRC was found to be significantly associated with decreased long-term survival, suggesting the importance of avoiding weight loss in survivors of CRC. Future research should attempt to further evaluate this association, accounting for whether this weight change was intentional or represents a marker of declining health. Cancer 2017;123:4701-4708. © 2017 American Cancer Society.

Diet, Physical Activity, and Body Weight in Cancer Survivorship

Diet, physical activity, and body weight have been shown to play an important role in cancer survivorship. The impact of each of these lifestyle factors differs slightly among cancer types, and adherence to recommended diet and physical activity guidelines has been associated with positive outcomes, including decrease in the risk of cancer recurrence and improvement of quality of life. Although there are compelling data that appropriate diet, physical activity, and body weight have beneficial effects in cancer survivorship, additional trials are needed to understand the relationship.

Doxorubicin effect is enhanced by sphingosine-1-phosphate signaling antagonist in breast cancer

BACKGROUND

Doxorubicin is one of the most commonly used chemotherapeutic drugs for breast cancer; however, its use is limited by drug resistance and side effects. We hypothesized that adding FTY720, a sphingosine-1-phosphate (S1P) receptor functional antagonist, to doxorubicin would potentiate its effects by suppression of drug-induced inflammation.

MATERIALS AND METHODS

The Cancer Genome Atlas, Gene Expression Omnibus data sets, and National Cancer Institute-60 panel were used for gene expressions and gene set enrichment analysis. E0771 syngeneic mammary tumor cells were used. OB/OB mice fed with western high-fat diet were used as an obesity model.

RESULTS

STAT3 expression was significantly increased after doxorubicin treatment in human breast cancer that implicates that doxorubicin evokes inflammation. Expression of sphingosine kinase 1, the enzyme that produces S1P and links inflammation and cancer, tended to be higher in doxorubicin-resistant human cancer and cell lines. In a murine breast cancer model, sphingosine kinase 1, S1P receptor 1, interleukin 6, and STAT3 were overexpressed in the doxorubicin-treated group, whereas all of them were significantly suppressed with addition of FTY720. Combination therapy synergistically suppressed cancer growth both in vitro and in vivo. Furthermore, combination therapy showed higher efficacy in an obesity breast cancer model, where high body mass index demonstrated trends toward worse disease-free and overall survival, and high-serum S1P levels in human patients and volunteers.

CONCLUSIONS

We found that FTY720 enhanced the efficacy of doxorubicin by suppression of drug-induced inflammation, and combination therapy showed stronger effect in obesity-related breast cancer.