The association of body mass index with tumor aggression among men undergoing radical prostatectomy

OBJECTIVES

To evaluate the association of preoperative body mass index (BMI) on adverse pathology in peripheral (PZ) and transition zone (TZ) tumors at time of prostatectomy for localized prostate cancer.

METHODS

Clinical and pathologic characteristics were obtained from up to 100 consecutive prostatectomy patients from 10 prostate surgeons. BMI groups included normal (18.5-24.9), overweight (25-29.9) and obese (> 29.9). "Aggressive" pathology was defined as the presence of Grade Group (GG) 3 or higher and/or pT3a or higher. Pathologic characteristics were evaluated for association with BMI using univariate analyses. Our primary outcome was the association of BMI with adverse pathology, which was assessed using logistic regression accounting for patient age. We hypothesized that obese BMI would be associated with aggressive TZ tumor.

RESULTS

Among 923 patients, 140 (15%) were classified as "normal" BMI, 413 (45%) were "overweight", and 370 (40%) were "obese." 474 patients (51%) had aggressive PZ tumors while 102 (11%) had aggressive TZ tumors. "Obese" BMI was not associated with aggressive TZ tumor compared to normal weight. Increasing BMI group was associated with overall increased risk of aggressive PZ tumor (HR 1.56 [95CI 1.04-2.34]; P = 0.03). Among patients with GG1 or GG2, increasing BMI was associated with presence of pT3a or higher TZ tumor (P = 0.03).

CONCLUSIONS

Increased BMI is associated with adverse pathology in PZ tumors. TZ adverse pathology risk may be increased among obese men with GG1 or GG2 disease, which has implications for future studies assessing behavioral change among men whose tumors are actively monitored.

The Time-Dependent Association Between Irritable Bowel Syndrome and All-Cause and Cause-Specific Mortality: A Prospective Cohort Study Within the UK Biobank

INTRODUCTION

Irritable bowel syndrome (IBS) is one of the most common functional gastrointestinal disorders, but few studies have evaluated mortality risks among individuals with IBS. We explored the association between IBS and all-cause and cause-specific mortality in the UK Biobank.

METHODS

We included 502,369 participants from the UK Biobank with mortality data through 2022. IBS was defined using baseline self-report and linkage to primary care or hospital admission data. We estimated hazard ratios (HRs) and 95% confidence intervals (CIs) for all-cause and cause-specific mortality using multivariable Cox proportional hazards regression models within partitioned follow-up time categories (0-5, >5-10, and >10 years).

RESULTS

A total of 25,697 participants (5.1%) had a history of IBS at baseline. After a median follow-up of 13.7 years, a total of 44,499 deaths occurred. Having an IBS diagnosis was strongly associated with lower risks of all-cause (HR = 0.70, 95% CI = 0.62-0.78) and all-cancer (HR = 0.69, 95% CI = 0.60-0.79) mortality in the first 5 years of follow-up. These associations were attenuated over follow-up, but even after 10 years of follow-up, associations remained inverse (all-cause: HR = 0.89, 95% CI = 0.84-0.96; all-cancer: HR = 0.87, 95% CI = 0.78-0.97) after full adjustment. Individuals with IBS had decreased risk of mortality from breast, prostate, and colorectal cancers in some of the follow-up time categories.

DISCUSSION

We found that earlier during follow-up, having diagnosed IBS was associated with lower mortality risk, and the association attenuated over time. Additional studies to understand whether specific factors, such as lifestyle and healthcare access, explain the inverse association between IBS and mortality are needed.

Association of Preoperative Lung Function with Complications after Lobectomy Using Race-Neutral and Race-Specific Normative Equations

Rationale: Pulmonary function testing (PFT) is performed to aid patient selection before surgical resection for non-small cell lung cancer (NSCLC). The interpretation of PFT data relies on normative equations, which vary by race, but the relative strength of association of lung function using race-specific or race-neutral normative equations with postoperative pulmonary complications is unknown. Objectives: To compare the strength of association of lung function, using race-neutral or race-specific equations, with surgical complications after lobectomy for NSCLC. Methods: We studied 3,311 patients who underwent lobectomy for NSCLC and underwent preoperative PFT from 2001 to 2021. We used Global Lung Function Initiative equations to generate race-specific and race-neutral normative equations to calculate percentage predicted forced expiratory volume in 1 second (FEV1%). The primary outcome of interest was the occurrence of postoperative pulmonary complications within 30 days of surgery. We used unadjusted and race-adjusted logistic regression models and least absolute shrinkage and selection operator analyses adjusted for relevant comorbidities to measure the association of race-specific and race-neutral FEV1% with pulmonary complications. Results: Thirty-one percent of patients who underwent surgery experienced pulmonary complications. Higher FEV1, whether measured with race-neutral (odds ratio [OR], 0.98 per 1% change in FEV1% [95% confidence interval (CI), 0.98-0.99]; P < 0.001) or race-specific (OR, 0.98 per 1% change in FEV1% [95% CI, 0.98-0.98]; P < 0.001) normative equations, was associated with fewer postoperative pulmonary complications. The area under the receiver operator curve for pulmonary complications was similar for race-adjusted race-neutral (0.60) and race-specific (0.60) models. Using least absolute shrinkage and selection operator regression, higher FEV1% was similarly associated with a lower rate of pulmonary complications in race-neutral (OR, 0.99 per 1% [95% CI, 0.98-0.99]) and race-specific (OR, 0.99 per 1%; 95% CI, 0.98-0.99) models. The marginal effect of race on pulmonary complications was attenuated in all race-specific models compared with all race-neutral models. Conclusions: The choice of race-specific or race-neutral normative PFT equations does not meaningfully affect the association of lung function with pulmonary complications after lobectomy for NSCLC, but the use of race-neutral equations unmasks additional effects of self-identified race on pulmonary complications.

Modulating a prebiotic food source influences inflammation and immune-regulating gut microbes and metabolites: insights from the BE GONE trial

BACKGROUND

Accessible prebiotic foods hold strong potential to jointly target gut health and metabolic health in high-risk patients. The BE GONE trial targeted the gut microbiota of obese surveillance patients with a history of colorectal neoplasia through a straightforward bean intervention.

METHODS

This low-risk, non-invasive dietary intervention trial was conducted at MD Anderson Cancer Center (Houston, TX, USA). Following a 4-week equilibration, patients were randomized to continue their usual diet without beans (control) or to add a daily cup of study beans to their usual diet (intervention) with immediate crossover at 8-weeks. Stool and fasting blood were collected every 4 weeks to assess the primary outcome of intra and inter-individual changes in the gut microbiome and in circulating markers and metabolites within 8 weeks. This study was registered on ClinicalTrials.gov as NCT02843425, recruitment is complete and long-term follow-up continues.

FINDINGS

Of the 55 patients randomized by intervention sequence, 87% completed the 16-week trial, demonstrating an increase on-intervention in diversity [n = 48; linear mixed effect and 95% CI for inverse Simpson index: 0.16 (0.02, 0.30); p = 0.02] and shifts in multiple bacteria indicative of prebiotic efficacy, including increased Faecalibacterium, Eubacterium and Bifidobacterium (all p < 0.05). The circulating metabolome showed parallel shifts in nutrient and microbiome-derived metabolites, including increased pipecolic acid and decreased indole (all p < 0.002) that regressed upon returning to the usual diet. No significant changes were observed in circulating lipoproteins within 8 weeks; however, proteomic biomarkers of intestinal and systemic inflammatory response, fibroblast-growth factor-19 increased, and interleukin-10 receptor-α decreased (p = 0.01).

INTERPRETATION

These findings underscore the prebiotic and potential therapeutic role of beans to enhance the gut microbiome and to regulate host markers associated with metabolic obesity and colorectal cancer, while further emphasizing the need for consistent and sustainable dietary adjustments in high-risk patients.

FUNDING

This study was funded by the American Cancer Society.

The association between inflammatory bowel disease and all-cause and cause-specific mortality in the UK Biobank

PURPOSE

Inflammatory bowel disease (IBD) has a rising global prevalence. However, the understanding of its impact on mortality remains inconsistent so we explored the association between IBD and all-cause and cause-specific mortality.

METHODS

This study included 502,369 participants from the UK Biobank, a large, population-based, prospective cohort study with mortality data through 2022. IBD was defined by baseline self-report or from primary care or hospital admission data. We estimated hazard ratios (HRs) and 95% confidence intervals (CIs) for all-cause and cause-specific mortality in multivariable Cox proportional hazards regression models.

RESULTS

A total of 5799 (1.2%) participants had a history of IBD at baseline. After a median follow-up of 13.7 years, 44,499 deaths occurred. Having IBD was associated with an increased risk of death from all causes (HR = 1.16, 95% CI = 1.07-1.24) and cancer (HR = 1.16, 95% CI = 1.05-1.30), particularly colorectal cancer (CRC) (HR = 1.56, 95% CI = 1.17-2.09). We observed elevated breast cancer mortality rates for individuals with Crohn's disease, and increased CRC mortality rates for individuals with ulcerative colitis. In stratified analyses of IBD and all-cause mortality, mortality risk differed by individuals' duration of IBD, age at IBD diagnosis, body mass index (BMI) (PHeterogeneity = 0.03) and smoking status (PHeterogeneity = 0.01). Positive associations between IBD and all-cause mortality were detected in individuals diagnosed with IBD for 10 years or longer, those diagnosed before the age of 50, all BMI subgroups except obese individuals, and in never or current, but not former smokers.

CONCLUSIONS

We found that having IBD was associated with increased risks of mortality from all causes, all cancers, and CRC. This underscores the importance of enhanced patient management strategies and targeted prevention efforts in individuals with IBD.

A Study of Dietary Patterns Derived by Cluster Analysis and Their Association With Metabolic Dysfunction-Associated Steatotic Liver Disease Severity Among Hispanic Patients

INTRODUCTION

Diet is a modifiable metabolic dysfunction-associated steatotic liver disease (MASLD) risk factor, but few studies have been conducted among Hispanic patients, despite the fact that MASLD prevalence and severity are highest among this ethnic subgroup. We aimed to identify prevalent dietary patterns among Hispanic patients using cluster analysis and to investigate associations with MASLD severity.

METHODS

This cross-sectional analysis included 421 Harris County MASLD Cohort participants who self-reported Hispanic ethnicity and completed baseline food frequency questionnaires. All included patients had MASLD, diagnosed per standard clinical criteria. K-means analysis was used to identify clusters of patients sharing similar dietary habits. Multivariable adjusted logistic regression was used to estimate associations of dietary clusters with aminotransferases among the overall sample and with histologic steatosis, metabolic dysfunction-associated steatohepatitis, and fibrosis among a subsample of patients who underwent liver biopsy within 6 months of their baseline food frequency questionnaire (n = 186).

RESULTS

We identified 2 clusters: a plant-food/prudent and a fast-food/meat pattern. The fast-food/meat pattern was associated with 2.47-fold increased odds (95% confidence interval 1.31-4.65) of more severe steatosis than the plant-food/prudent pattern after adjusting for demographics, metabolic score, physical activity, and alcohol ( q = 0.0159). No significant association was observed between diet and aminotransferases, metabolic dysfunction-associated steatohepatitis, or fibrosis.

DISCUSSION

Given the importance of sociocultural influences on diet, it is important to understand dietary patterns prevalent among Hispanic patients with MASLD. Using cluster analysis, we identified 1 plant-based pattern vs 1 distinct fast-food/meat-based pattern associated with detrimental effects among our population. This information is an important starting point for tailoring dietary interventions for Hispanic patients with MASLD.

Gut Microbiome in Patients With Early-Stage and Late-Stage Melanoma

Importance

The gut microbiome modulates the immune system and responses to immunotherapy in patients with late-stage melanoma. It is unknown whether fecal microbiota profiles differ between healthy individuals and patients with melanoma or if microbiota profiles differ among patients with different stages of melanoma. Defining gut microbiota profiles in individuals without melanoma and those with early-stage and late-stage melanoma may reveal features associated with disease progression.

Objective

To characterize and compare gut microbiota profiles between healthy volunteers and patients with melanoma and between patients with early-stage and late-stage melanoma.

Design, Setting, and Participants

This single-site case-control study took place at an academic comprehensive cancer center. Fecal samples were collected from systemic treatment-naive patients with stage I to IV melanoma from June 1, 2015, to January 31, 2019, and from healthy volunteers from June 1, 2021, to January 31, 2022. Patients were followed up for disease recurrence until November 30, 2021.

Main Outcomes and Measures

Fecal microbiota was profiled by 16S ribosomal RNA sequencing. Clinical and pathologic characteristics, treatment, and disease recurrence were extracted from electronic medical records. Fecal microbiome diversity, taxonomic profiles and inferred functional profiles were compared between groups.

Results

A total of 228 participants were enrolled (126 men [55.3%]; median age, 59 [range, 21-90] years), including 49 volunteers without melanoma, 38 patients with early-stage melanoma (29 with stage I or melanoma in situ and 9 with stage II), and 141 with late-stage melanoma (66 with stage III and 75 with stage IV). Community differences were observed between patients with melanoma and volunteers. Patients with melanoma had a higher relative abundance of Fusobacterium compared with controls on univariate analysis (0.19% vs 0.003%; P < .001), but this association was attenuated when adjusted for covariates (log2 fold change of 5.18 vs controls; P = .09). Microbiomes were distinct between patients with early-stage and late-stage melanoma. Early-stage melanoma had a higher alpha diversity (Inverse Simpson Index 14.6 [IQR, 9.8-23.0] vs 10.8 [IQR, 7.2-16.8]; P = .003), and a higher abundance of the genus Roseburia on univariate analysis (2.4% vs 1.2%; P < .001) though statistical significance was lost with covariate adjustment (log2 fold change of 0.86 vs controls; P = .13). Multiple functional pathways were differentially enriched between groups. No associations were observed between the microbial taxa and disease recurrence in patients with stage III melanoma treated with adjuvant immunotherapy.

Conclusions and Relevance

The findings of this case-control study suggest that fecal microbiota profiles were significantly different among patients with melanoma and controls and between patients with early-stage and late-stage melanoma. Prospective investigations of the gut microbiome and changes that occur with disease progression may identify future microbial targets for intervention.

Coffee Intake, Caffeine Metabolism Genotype, and Survival Among Men with Prostate Cancer

BACKGROUND

Coffee intake may lower prostate cancer risk and progression, but postdiagnosis outcomes by caffeine metabolism genotype are not well characterized.

OBJECTIVE

To evaluate associations between coffee intake, caffeine metabolism genotype, and survival in a large, multicenter study of men with prostate cancer.

DESIGN, SETTING, AND PARTICIPANTS

Data from The PRACTICAL Consortium database for 5727 men with prostate cancer from seven US, Australian, and European studies were included. The cases included had data available for the CYP1A2 -163C>A rs762551 single-nucleotide variant associated with caffeine metabolism, coffee intake, and >6 mo of follow-up.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Multivariable-adjusted Cox proportional hazards models across pooled patient-level data were used to compare the effect of coffee intake (categorized as low [reference], high, or none/very low) in relation to overall survival (OS) and prostate cancer-specific survival (PCSS), with stratified analyses conducted by clinical disease risk and genotype.

RESULTS AND LIMITATIONS

High coffee intake appeared to be associated with longer PCSS (hazard ratio [HR] 0.85, 95% confidence interval [CI] 0.68-1.08; p = 0.18) and OS (HR 0.90, 95% CI 0.77-1.07; p = 0.24), although results were not statistically significant. In the group with clinically localized disease, high coffee intake was associated with longer PCSS (HR 0.66, 95% CI 0.44-0.98; p = 0.040), with comparable results for the group with advanced disease (HR 0.92, 95% CI 0.69-1.23; p = 0.6). High coffee intake was associated with longer PCSS among men with the CYP1A2 AA (HR 0.67, 95% CI 0.49-0.93; p = 0.017) but not the AC/CC genotype (p = 0.8); an interaction was detected (p = 0.042). No associations with OS were observed in subgroup analyses (p > 0.05). Limitations include the nominal statistical significance and residual confounding.

CONCLUSIONS

Coffee intake was associated with longer PCSS among men with a CYP1A2 -163AA (*1F/*1F) genotype, a finding that will require further replication.

PATIENT SUMMARY

It is likely that coffee intake is associated with longer prostate cancer-specific survival in certain groups, but more research is needed to fully understand which men may benefit and why.

Translating energy balance research from the bench to the clinic to the community: Parallel animal-human studies in cancer

Advances in energy balance and cancer research to date have largely occurred in siloed work in rodents or patients. However, substantial benefit can be derived from parallel studies in which animal models inform the design of clinical and population studies or in which clinical observations become the basis for animal studies. The conference Translating Energy Balance from Bench to Communities: Application of Parallel Animal-Human Studies in Cancer, held in July 2021, convened investigators from basic, translational/clinical, and population science research to share knowledge, examples of successful parallel studies, and strong research to move the field of energy balance and cancer toward practice changes. This review summarizes key topics discussed to advance research on the role of energy balance, including physical activity, body composition, and dietary intake, on cancer development, cancer outcomes, and healthy survivorship.

Obesity Is Associated with Altered Tumor Metabolism in Metastatic Melanoma

PURPOSE

Overweight/obese (OW/OB) patients with metastatic melanoma unexpectedly have improved outcomes with immune checkpoint inhibitors (ICI) and BRAF-targeted therapies. The mechanism(s) underlying this association remain unclear, thus we assessed the integrated molecular, metabolic, and immune profile of tumors, as well as gut microbiome features, for associations with patient body mass index (BMI).

EXPERIMENTAL DESIGN

Associations between BMI [normal (NL < 25) or OW/OB (BMI ≥ 25)] and tumor or microbiome characteristics were examined in specimens from 782 patients with metastatic melanoma across 7 cohorts. DNA associations were evaluated in The Cancer Genome Atlas cohort. RNA sequencing from 4 cohorts (n = 357) was batch corrected and gene set enrichment analysis (GSEA) by BMI category was performed. Metabolic profiling was conducted in a subset of patients (x = 36) by LC/MS, and in flow-sorted melanoma tumor cells (x = 37) and patient-derived melanoma cell lines (x = 17) using the Seahorse XF assay. Gut microbiome features were examined in an independent cohort (n = 371).

RESULTS

DNA mutations and copy number variations were not associated with BMI. GSEA demonstrated that tumors from OW/OB patients were metabolically quiescent, with downregulation of oxidative phosphorylation and multiple other metabolic pathways. Direct metabolite analysis and functional metabolic profiling confirmed decreased central carbon metabolism in OW/OB metastatic melanoma tumors and patient-derived cell lines. The overall structure, diversity, and taxonomy of the fecal microbiome did not differ by BMI.

CONCLUSIONS

These findings suggest that the host metabolic phenotype influences melanoma metabolism and provide insight into the improved outcomes observed in OW/OB patients with metastatic melanoma treated with ICIs and targeted therapies. See related commentary by Smalley, p. 5.

Gut microbiome features associated with liver fibrosis in Hispanics, a population at high risk for fatty liver disease

BACKGROUND AND AIMS

Hispanics are disproportionately affected by NAFLD, liver fibrosis, cirrhosis, and HCC. Preventive strategies and noninvasive means to identify those in this population at high risk for liver fibrosis, are urgently needed. We aimed to characterize the gut microbiome signatures and related biological functions associated with liver fibrosis in Hispanics and identify environmental and genetic factors affecting them.

APPROACH AND RESULTS

Subjects of the population-based Cameron County Hispanic Cohort (CCHC; n = 217) were screened by vibration-controlled transient elastography (FibroScan). Among them, 144 (66.7%) had steatosis and 28 (13.0%) had liver fibrosis. The gut microbiome of subjects with liver fibrosis was enriched with immunogenic commensals (e.g., Prevotella copri, Holdemanella, Clostridiaceae 1) and depleted of Bacteroides caccae, Parabacteroides distasonis, Enterobacter, and Marinifilaceae. The liver fibrosis-associated metagenome was characterized by changes in the urea cycle, L-citrulline biosynthesis and creatinine degradation pathways, and altered synthesis of B vitamins and lipoic acid. These metagenomic changes strongly correlated with the depletion of Parabacteroides distasonis and enrichment of Prevotella and Holdemanella. Liver fibrosis was also associated with depletion of bacterial pathways related to L-fucose biosynthesis. Alcohol consumption, even moderate, was associated with high Prevotella abundance. The single-nucleotide polymorphisms rs3769502 and rs7573751 in the NCK adaptor protein 2 (NCK2) gene positively associated with high Prevotella abundance.

CONCLUSION

Hispanics with liver fibrosis display microbiome profiles and associated functional changes that may promote oxidative stress and a proinflammatory environment. These microbiome signatures, together with NCK2 polymorphisms, may have utility in risk modeling and disease prevention in this high-risk population.

Physical activity and diet quality in relation to non-alcoholic fatty liver disease: A cross-sectional study in a representative sample of U.S. adults using NHANES 2017-2018

The association of physical activity (PA) and diet quality with non-alcoholic fatty liver disease (NAFLD) and NAFLD-related fibrosis have never been examined in a representative sample of U.S. adults using a more precise form of measuring NAFLD. The purpose of this study was to assess the associations of PA and diet quality (Healthy Eating Index [HEI]-2015) with NAFLD and a subset with advanced fibrosis (F3-4) as assessed by vibration-controlled transient elastography with controlled attenuation parameter in a representative sample of U.S. adults. This cross-sectional analysis uses data from 2017-2018 National Health and Nutrition Examination Survey. NAFLD was defined as controlled attenuation parameter ≥285 dB/m, and high likelihood of advanced fibrosis as liver stiffness measurements ≥8.6 kPa. Associations of HEI-2015 from 24-h dietary recalls and self-reported PA and sedentary behavior were estimated in multivariable-adjusted logistic regression models of NAFLD and advanced fibrosis. In 2892 adults, the prevalence of NAFLD and advanced fibrosis was 35.6% and 5.6%, respectively. We found that high adherence to U.S. dietary recommendations (highest vs. lowest HEI-2015 tertile) and more PA (middle tertile vs. lowest) were associated with reduced odds of NAFLD (Adjusted OR and 95% CI; 0.60 (0.44, 0.84) and 0.65 (0.42, 0.99), respectively). More PA was inversely associated with advanced fibrosis (Adjusted OR = 0.35, 95%CI 0.16, 0.75). Diet quality and PA are associated with reduced odds of NAFLD, and PA may be critical even for those with advanced liver disease. These behaviors should be the focus of targeted public health interventions.

Dietary fiber and probiotics influence the gut microbiome and melanoma immunotherapy response

Gut bacteria modulate the response to immune checkpoint blockade (ICB) treatment in cancer, but the effect of diet and supplements on this interaction is not well studied. We assessed fecal microbiota profiles, dietary habits, and commercially available probiotic supplement use in melanoma patients and performed parallel preclinical studies. Higher dietary fiber was associated with significantly improved progression-free survival in 128 patients on ICB, with the most pronounced benefit observed in patients with sufficient dietary fiber intake and no probiotic use. Findings were recapitulated in preclinical models, which demonstrated impaired treatment response to anti–programmed cell death 1 (anti–PD-1)–based therapy in mice receiving a low-fiber diet or probiotics, with a lower frequency of interferon-γ–positive cytotoxic T cells in the tumor microenvironment. Together, these data have clinical implications for patients receiving ICB for cancer.

Dietary N-Nitroso Compounds and Risk of Hepatocellular Carcinoma: A USA-Based Study

BACKGROUND AND AIMS

N-nitroso compounds (NOCs) are among the most potent dietary carcinogens. N-nitrosodiethylamine (NDEA), N-nitrosodimethylamine (NDMA), and N-nitrosopiperidine (NPIP) are abundant in foods and carcinogenic to the liver. We investigated the relationship between dietary NOCs and HCC risk.

APPROACH AND RESULTS

In this large, hospital-based, case-control study of 827 pathologically or radiologically confirmed HCC cases and 1,013 controls, NOC intake was calculated by linking food frequency questionnaire-derived dietary data with a comprehensive NOC concentration database. Multivariable-adjusted ORs and 95% CIs of HCC by quartiles of NOC consumption were estimated using logistic regression models, with the lowest quartile as the referent. We further investigated joint effects of consuming the highest quartile of NOCs that were associated with increased HCC risk and hepatitis, diabetes, or alcohol drinking on HCC risk. After adjustment for confounding factors, higher intake of NDEA from plant sources (ORQ4 vs. Q1  = 1.58; 95% CI = 1.03-2.41), NDMA from plant sources (ORQ4 vs. Q1  = 1.54; 95% CI = 1.01-2.34), and NPIP (ORQ4 vs. Q1  = 2.52; 95% CI = 1.62-3.94) was associated with increased HCC risk. No association was observed for nitrate or total NOC intake and HCC risk. Higher consumption of HCC-inducing NOCs and positive hepatitis virus status jointly increased the risk of developing HCC.

CONCLUSIONS

In conclusion, though some of our findings may indicate the presence of reverse causation owing to lower meat intake among cases with chronic liver diseases before HCC diagnosis, the potent dietary HCC carcinogens, NDEA, NDMA, and NPIP, and their enhanced carcinogenic effects among chronic carriers of hepatitis virus warrant further prospective investigation.

Dietary Intake of Fatty Acids and Risk of Pancreatic Cancer: A Case-Control Study

BACKGROUND

Epidemiological findings on dietary fat intake and risk of pancreatic cancer (PanC) are inconsistent.

OBJECTIVES

This study aimed to determine the association between types of dietary fat intake and PanC.

METHODS

We conducted a hospital-based case-control study in 957 pathologically confirmed PanC cases and 938 cancer-free controls. Cases and controls were frequency matched by age, sex, and race. Dietary information was collected using a self-administered validated FFQ. Unconditional logistic regression models were used to estimate the ORs and 95% CIs of PanC risk by quintiles of fat intake with the lowest quintile as referent and with adjustment for other risk factors and dietary factors.

RESULTS

We observed no difference in (median) intake of total fat standardized for energy among cases versus controls. The multivariable-adjusted OR (95% CI) of the highest versus the lowest quintile of intake (ORQ5 compared with Q1) was 2.51 (1.68-3.72) for fat from animal sources and 0.41 (0.29-0.58) for fat from plant sources. Intakes of total MUFA, total PUFA, and linoleic (n-6) and long chain n-3 fatty acids were inversely associated with PanC (ORQ5 compared with Q1 and 95% CI: 0.55 [0.36-0.82], 0.59 [0.42-0.82], 0.64 [0.43-0.84], and 0.60 [0.42-0.84], respectively). Arachidonic acid (n-6) and several SFAs were positively associated with PanC.

CONCLUSION

Although some observed associations with pancreatic cancer risk could be explained by reverse causation, the potential protective associations with intakes of largely plant-derived PUFAs and MUFAs and fish-derived long chain n-3 PUFAs warrant further prospective investigation.

Abstract 2909: Tumor microbiota profiles are associated with molecular subtype and survival in colorectal cancer patients

Background: The intestinal microbiome is intimately involved in the pathogenesis of colorectal cancer and likely holds further insights to improve the treatment and management of this deadly disease. In a clinical cohort of patients with colon and rectal cancers, we characterized the tumor microbiota of surgical specimens and evaluated associations with prognostic factors, consensus molecular subtypes (CMS), and survival.

Methods: In 167 patients diagnosed with stage II through IV colon and/or rectal cancer who underwent evaluation and surgical resection (no prior systemic therapy) at The University of Texas MD Anderson Cancer, we characterized the tumor microbiome via 16S rRNA gene sequencing. Each patient's tumor was classified via CMS, a gene expression-based colorectal cancer classification system; and all patients were prospectively followed for disease progression, recurrence, or death. Microbiota diversity and composition were assessed with regard to clinicopathologic and tumor features; and associations with survival were further evaluated in multivariable Cox proportional hazards models.

Results: Left- vs. right-sided colon tumors were characterized by higher microbial diversity, distinct community features, and increased abundance of Bacteroides and Fusobacterium. CMS1 (microsatellite instability immune) vs. CMS2 (canonical) tumors were characterized by higher Bacteroides and Fusobacterium and lower Escherichia (all P&lt;0.05). Fusobacterium-positive and Escherichia-positive tumors were associated with improved 5-year overall survival [presence vs. absence, multivariable-adjusted HR and 95% CI: 0.43 (0.20-0.93) and 0.32 (0.19-0.78), respectively]. Bacteroides was enriched among stage II/III patients who progressed within 2-years (log-rank p&lt;0.001).

Conclusions: Our findings are consistent with those of other groups suggesting the landscape of the tumor microbiome differs by sidedness and molecular subtype, holding important clues and exploitable targets to improve outcomes in colorectal cancer patients.

Citation Format: Fangyu Li, Michael G. White, Jennifer Davis, Kristi L. Hoffman, David Menter, Nadim Ajami, Xiaotao Zhang, Jeffrey S. Morris, Robert R. Jenq, Joseph Petrosino, Jennifer A. Wargo, Scott Kopetz, Carrie R. Daniel. Tumor microbiota profiles are associated with molecular subtype and survival in colorectal cancer patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2909.

Abstract LB223: Beans to Enrich the Gut microbiome vs. Obesity's Negative Effects: First results from the BE GONE Trial in high-risk colorectal patients

Background: Dry beans are a prebiotic food source rich in bioactive compounds with anti-inflammatory, anti-lipidemic and chemopreventive properties. The BE GONE trial tested the impact of an increase in dry bean consumption on gut microbiota and blood lipid profiles in high-risk colorectal (CR) patients otherwise consuming their usual diet. Methods: Following initiation of the pilot protocol (July 2016) among patients with a high-risk BMI and/or waist circumference and history of precancerous CR polyps, the crossover trial was expanded to patients with a history of CR cancer (May 2017). Patients were block randomized according to no vs. regular use of chronic disease medications commonly prescribed in the target population. Following a 4-week run-in/equilibration period, participants were randomized to continue the control diet (usual diet, no dry beans) or to begin the intervention diet (usual diet + dry beans). The intervention included a 2-week ramp-up to 1 cup/day navy beans (12 g dietary fiber; 14 g protein; 200 kcal) continued for an additional 6 weeks. Dietary habits, body weight, and other lifestyle parameters were monitored throughout the 20-week study. We characterized the 16Sv4 rDNA microbiome (Illumina MiSeq) and CLIA cholesterol panel in serial stool and fasting blood samples collected at baseline, week 4, and week 8 for each crossover period (n=249). Longitudinal analyses were conducted using generalized linear mixed models with random intercept and slope adjusted for chronic disease medication use examining the post-intervention effect from baseline to 4 weeks and baseline to 8 weeks. Results: Eligible patients were enrolled in the 4-week run-in/equilibration (n=69). Of these, 55 were randomized and 50 completed the 20-week trial in December 2019 with &gt;80% compliance. Primary reasons for withdrawal were work/travel/family obligations. Half (54%) of the participants were male, 74% were CR cancer survivors, 76% were white (non-Hispanic) and 40% were on statins and/or metformin. Pre-study dietary profiles were characterized by low mean intake of legumes (&lt;3 servings/month) and dietary fiber (17 g/day). The 8-week increase in bean intake significantly increased the inverse Simpson index [effect estimate and 95% CI: 1.59 (0.10, 3.08)], a diversity measure reflecting a greater variety of bacteria with a more even relative abundance. Longitudinal analyses restricted to taxa present in &gt;80% of patients at baseline, revealed significantly decreased Anaerostipes and Streptococcus at week 4 and increased Faecalibacterium at week 8, along with temporal fluctuations in other known specialized (e.g., pectin) and versatile fiber-fermenting bacteria of the Lachnospiraceae and Ruminococcaceae families. A modest decrease in LDL cholesterol was observed at 8-weeks [-2.64 (-6.91, 1.62)] Conclusions: Early results of the BE GONE trial suggest that an 8-week increase in dry bean intake may be sufficient to balance or enrich the gut microbiome of high-risk CR patients. Continued sample processing and analysis, including stool metagenomics and blood metabolomics should continue to shed light on functional interactions relevant to the human host.

Citation Format: Xiaotao Zhang, Kristi L. Hoffman, Fangyu Li, Ehsan Irajizad, Gladys Browman, Karen Basen-Engquist, Samir Hanash, Paul Scheet, Pablo C. Okhuysen, Scott Kopetz, Joseph Petrosino, Carrie R. Daniel. Beans to Enrich the Gut microbiome vs. Obesity's Negative Effects: First results from the BE GONE Trial in high-risk colorectal patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr LB223.

Satiety does not affect neuroaffective electrophysiological responses to food-related or emotional visual cues

Continuing to eat even when full leads to excessive calorie consumption and obesity. Thus, understanding brain responses to food cues when satiated has important implications for weight control interventions. We used the late positive potential (LPP, a component of the event-related potentials (ERP) indexing motivational relevance) to determine the extent to which satiety affects brain responses to images of highly palatable foods (high-fat, high-sugar), high and low motivationally relevant (pleasant, unpleasant) and neutral stimuli in a sample of obese (body mass index [BMI] ≥ 30 kg/m2) and lean (BMI < 25 kg/m2) individuals. Satiated individuals (N = 55, 21 with BMI ≥ 30 kg/m2) were fed a nutritional drink prior to the experimental session and were individually matched with 55 unsatiated individuals who saw the same images during a passive viewing task. Satiety did not affect LPP response to food-related or motivationally relevant cues in either BMI < 25 kg/m2 or BMI ≥ 30 kg/m2 individuals (p = .6). Irrespective of satiety, all participants showed larger LPPs as a function of the images' motivational relevance. There were no differences in LPP amplitude between BMI < 25 kg/m2 and BMI ≥ 30 kg/m2 individuals for any picture category, including food. However, within-group comparisons showed that BMI < 25 kg/m2 individuals had larger LPPs to low motivationally relevant pleasant images than to food-related cues (p < .001); this difference was not significant for BMI ≥ 30 kg/m2 individuals. Although satiety does not affect LPP responses to food-related cues, these results highlight the importance of evaluating reactivity to food-related cues in relation to other motivationally relevant stimuli. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Adherence to the Mediterranean diet and grade group progression in localized prostate cancer: An active surveillance cohort

BACKGROUND

The Mediterranean diet (MD) may be beneficial for men with localized prostate cancer (PCa) on active surveillance (AS) because of its anti-inflammatory, antilipidemic, and chemopreventive properties. This study prospectively investigated adherence to the MD with Gleason score progression and explored associations by diabetes status, statin use, and other factors.

METHODS

Men with newly diagnosed PCa on an AS protocol (n = 410) completed a baseline food frequency questionnaire, and the MD score was calculated across 9 energy-adjusted food groups. Cox proportional hazards models were fit to evaluate multivariable-adjusted associations of the MD score with progression-free survival; progression was defined as an increase in the Gleason grade group (GG) score over a biennial monitoring regimen.

RESULTS

In this cohort, 15% of the men were diabetic, 44% of the men used statins, and 76 men progressed (median follow-up, 36 months). After adjustments for clinical factors, higher adherence to the MD was associated with a lower risk of GG progression among all men (hazard ratio [HR] per 1-unit increase in MD score, 0.88; 95% confidence interval [CI], 0.77-1.01), non-White men (HR per 1-unit increase in MD score, 0.64; 95% CI, 0.45-0.92; P for interaction = .07), and men without diabetes (HR per 1-unit increase in MD score, 0.82; 95% CI, 0.71-0.96; P for interaction = .03). When joint effects of the MD score and statin use were examined, a similar risk reduction was observed among men with high MD scores who did not use statins in comparison with men with low/moderate MD scores with no statin use.

CONCLUSIONS

The MD is associated with a lower risk of GG progression in men on AS, and this is consistent with prior reports about the MD and reduced cancer morbidity and mortality.

Baseline Oral Microbiome and All-cancer Incidence in a Cohort of Nonsmoking Mexican American Women

Given the increasing evidence that the oral microbiome is involved in obesity, diabetes, and cancer risk, we investigated baseline oral microbiota profiles in relation to all-cancer incidence among nonsmoking women enrolled in a Texas cohort of first- and second-generation immigrants of Mexican origin. We characterized the 16Sv4 rDNA microbiome in oral mouthwash samples collected at baseline from a representative subset of 305 nonsmoking women, ages 20-75 years. We evaluated within- (alpha) and between-sample (beta) diversity by incident cancer status and applied linear discriminant analysis (LDA) effect size analysis to assess differentially abundant taxa. Diversity and candidate taxa in relation to all-cancer incidence were evaluated in multivariable-adjusted Cox regression models. Over 8.8 median years of follow-up, 31 incident cancer cases were identified and verified. Advanced age, greater acculturation, and cardiometabolic risk factors were associated with all-cancer incidence. Higher alpha diversity (age-adjusted P _difference < 0.01) and distinct biological communities (P _difference = 0.002) were observed by incident cancer status. Each unit increase in the Shannon diversity index yielded >8-fold increase in all-cancer and obesity-related cancer risk [multivariable-adjusted HR (95% confidence interval), 8.11 (3.14-20.94) and 10.72 (3.30-34.84), respectively] with similar findings for the inverse Simpson index. Streptococcus was enriched among women who did not develop cancer, while Fusobacterium, Prevotella, Mogibacterium, Campylobacter, Lachnoanaerobaculum, Dialister, and Atopobium were higher among women who developed cancer (LDA score ≥ 3; q-value < 0.01). This initial study of oral microbiota and overall cancer risk in nonsmoking Mexican American women suggests the readily accessible oral microbiota as a promising biomarker. PREVENTION RELEVANCE: Mexican American women suffer a disproportionate burden of chronic health conditions that increase cancer risk. Few investigations of the microbiome, a key determinant of host health, have been conducted among this group. Oral microbiota profiles may provide early and accessible cancer biomarker data on invasive bacteria or community disruptions.

Dietary inflammatory potential in relation to the gut microbiome: results from a cross-sectional study

Diet has direct and indirect effects on health through inflammation and the gut microbiome. We investigated total dietary inflammatory potential via the literature-derived index (Dietary Inflammatory Index (DII®)) with gut microbiota diversity, composition and function. In cancer-free patient volunteers initially approached at colonoscopy and healthy volunteers recruited from the medical centre community, we assessed 16S ribosomal DNA in all subjects who provided dietary assessments and stool samples (n 101) and the gut metagenome in a subset of patients with residual fasting blood samples (n 34). Associations of energy-adjusted DII scores with microbial diversity and composition were examined using linear regression, permutational multivariate ANOVA and linear discriminant analysis. Spearman correlation was used to evaluate associations of species and pathways with DII and circulating inflammatory markers. Across DII levels, α- and β-diversity did not significantly differ; however, Ruminococcus torques, Eubacterium nodatum, Acidaminococcus intestini and Clostridium leptum were more abundant in the most pro-inflammatory diet group, while Akkermansia muciniphila was enriched in the most anti-inflammatory diet group. With adjustment for age and BMI, R. torques, E. nodatum and A. intestini remained significantly associated with a more pro-inflammatory diet. In the metagenomic and fasting blood subset, A. intestini was correlated with circulating plasminogen activator inhibitor-1, a pro-inflammatory marker (rho = 0·40), but no associations remained significant upon correction for multiple testing. An index reflecting overall inflammatory potential of the diet was associated with specific microbes, but not overall diversity of the gut microbiome in our study. Findings from this preliminary study warrant further research in larger samples and prospective cohorts.

A Mixed Methods Study on Engagement and Satisfaction with a Digitally-Enhanced Pilot Intervention Among African American and Hispanic Women

African American and Hispanic women report less physical activity (PA) than non-Hispanic White women. As such, a digitally-enhanced 16-week social support pilot intervention was conducted to promote PA among African American and Hispanic women dyads. This study quantitatively and qualitatively examined the engagement and satisfaction of participants (N = 30; 15 dyads) assigned to the intervention. Intervention participants received telephone counseling calls based on motivational interviewing and a Jawbone UP activity monitor. Intervention engagement and satisfaction data were collected from the Jawbone UP, call logs, self-report questionnaires conducted at the 16-week follow-up, and two post-intervention focus groups. Nonparametric tests assessed group differences across engagement and satisfaction measures, and a manually-driven coding scheme was used to evaluate emerging themes from qualitative text. Participants demonstrated high engagement in the telephone counseling sessions and moderate engagement with the Jawbone UP. Friend/co-worker dyads and participants who were 45 years and older were more likely to use the device. Qualitative results emphasized participants' appreciation for the counseling calls, the Jawbone UP, and the overall dyadic framework of the study to collectively nurture social support and accountability for PA. Overall, the intervention group reacted positively to study components. Additional research is needed to understand the role of technology in facilitating long-lasting PA change via social support in minority populations.

Epidemiology and Molecular-Pathologic Characteristics of CpG Island Methylator Phenotype (CIMP) in Colorectal Cancer

BACKGROUND

CpG island methylator phenotype (CIMP) forms a distinct epigenetic phenotype in colorectal cancer (CRC). Though associated with distinct clinicopathologic characteristics, limited evidence exists of the association of CIMP with patient's reported lifestyle factors and tumor molecular characteristics. We assessed the associations of these characteristics in a pooled analysis of CRC patients.

PATIENTS AND METHODS

We pooled data from 3 CRC patient cohorts: Assessment of Targeted Therapies Against Colorectal Cancer (ATTACC), biomarker-based protocol (Integromics), and The Cancer Genome Atlas (TCGA). CIMP was measured using the classical 6-gene methylated-in-tumor (MINT) marker panel (MINT1, MINT2, MINT31, p14, p16, and MLH1) in ATTACC and genome-wide human methylation arrays in Integromics and TCGA, respectively. CIMP-High (CIMP-H) was defined as ≥ 3 of 6 methylated markers in ATTACC. In TCGA and Integromics, CIMP-H group was defined on the basis of clusters of methylation profiles and high levels of methylation in tumor samples. Baseline comparisons of characteristics across CIMP groups (CIMP-H vs. CIMP-0) were performed by Student t test or chi-square test for continuous or categorical variables, respectively. Further logistic regression analyses were performed to compute the odds ratio (OR) of these associations.

RESULTS

Pooled prevalence of CIMP-H was 22% across 3 data sets. CIMP-H CRC tumors were associated with older age at diagnosis (OR, 1.02; 95% confidence interval [CI], 1.01, 1.03), microsatellite instability-high (MSI-H) status (OR, 9.15; 95% CI, 4.45, 18.81), BRAF mutation (OR, 7.70; 95% CI, 4.98, 11.87), right-sided tumor location (OR, 2.40; 95% CI, 1.78, 3.22), poor differentiation (OR, 2.94; 95% CI, 1.95, 4.45), and mucinous histology (OR, 2.47; 95% CI, 1.77, 3.47), as reported previously in the literature. CIMP-H tumors were also found to be associated with self-reported history of alcohol consumption (OR, ever vs. never, 1.58; 95% CI, 1.07, 2.34). Pathologically, CIMP-H tumors were associated with the presence of intraepithelial lymphocytes (OR, 3.31; 95% CI, 1.41, 7.80) among patients in the Integromics cohort.

CONCLUSION

CIMP-H tumors were associated with history of alcohol consumption and presence of intraepithelial lymphocytes. In addition, we confirmed the previously known association of CIMP with age, MSI-H status, BRAF mutation, sidedness, and mucinous histology. Molecular pathologic epidemiology associations help us explore the underlying association of lifestyle and clinical factors with molecular subsets like CIMP and help guide cancer prevention and treatment strategies.

Modulating the microbiome to improve therapeutic response in cancer

Although novel therapies, including immunotherapy, have dramatically improved outcomes for many patients with cancer, overall outcomes are heterogeneous and existing biomarkers do not reliably predict response. To date, predictors of response to cancer therapy have largely focused on tumour-intrinsic features; however, there is growing evidence that other host factors (eg, host genomics and the microbiome) can substantially affect therapeutic response. The microbiome, which refers to microbiota within a host and their collective genomes, is becoming increasingly recognised for its influence on host immunity, as well as therapeutic responses to cancer treatment. Importantly, microbiota can be modified via several different strategies, affording new angles in cancer treatment to improve outcomes. In this Review, we examine the evidence on the role of the microbiome in cancer and therapeutic response, factors that influence and shape host microbiota, strategies to modulate the microbiome, and present key unanswered questions to be addressed in ongoing and future research.

The BE GONE trial study protocol: a randomized crossover dietary intervention of dry beans targeting the gut microbiome of overweight and obese patients with a history of colorectal polyps or cancer

BACKGROUND

Mouse and human studies support the promise of dry beans to improve metabolic health and to lower cancer risk. In overweight/obese patients with a history of colorectal polyps or cancer, the Beans to Enrich the Gut microbiome vs. Obesity's Negative Effects (BE GONE) trial will test whether and how an increase in the consumption of pre-cooked, canned dry beans within the context of usual diet and lifestyle can enhance the gut landscape to improve metabolic health and reduce cancer risk.

METHODS/DESIGN

This randomized crossover trial is designed to characterize changes in (1) host markers spanning lipid metabolism, inflammation, and obesity-related cancer risk; (2) compositional and functional profiles of the fecal microbiome; and (3) host and microbial metabolites. With each subject serving as their own control, the trial will compare the participant's usual diet with (intervention) and without (control) dry beans. Canned, pre-cooked dry beans are provided to participants and the usual diet continually assessed and monitored. Following a 4-week run-in and equilibration period, each participant provides a total of 5 fasting blood and 6 stool samples over a total period of 16 weeks. The intervention consists of a 2-week ramp-up of dry bean intake to 1 cup/d, which is then continued for an additional 6 weeks. Intra- and inter-individual outcomes are assessed across each crossover period with consideration of the joint or modifying effects of the usual diet and baseline microbiome.

DISCUSSION

The BE GONE trial is evaluating a scalable dietary prevention strategy targeting the gut microbiome of high-risk patients to mitigate the metabolic and inflammatory effects of adiposity that influence colorectal cancer risk, recurrence, and survival. The overarching scientific goal is to further elucidate interactions between diet, the gut microbiome, and host metabolism. Improved understanding of the diet-microbiota interplay and effective means to target these relationships will be key to the future of clinical and public health approaches to cancer and other major diet- and obesity-related diseases.

TRIAL REGISTRATION

This protocol is registered with the U.S. National Institutes of Health trial registry, ClinicalTrials.gov, under the identifier NCT02843425. First posted July 25, 2016; last verified January 25, 2019.

Dietary N-nitroso compounds and risk of pancreatic cancer: results from a large case-control study

N-nitroso compounds (NOCs) are among the most potent dietary and pancreatic carcinogens. N-nitrosodiethylamine (NDEA) and N-nitrosodimethylamine (NDMA) are the most prevalent NOCs identified in foods. Using a validated and comprehensive N-nitroso database developed to estimate total NOCs and important individual NOCs from food intake, we investigated dietary exposure to NOCs in relation to pancreatic cancer in a large matched case-control study. Self-administered food frequency questionnaires were collected from 957 pathologically confirmed pancreatic ductal adenocarcinoma cases and 938 frequency-matched controls. For each food item, frequency of intake and portion size in grams was multiplied by the estimated NOC concentration from the N-nitroso database. Multiple unconditional logistic regression models were used to estimate the odds ratios (OR) and 95% confidence intervals (CIs) for pancreatic cancer risk by quartiles of NOCs and major food group contributors to NOCs, with the lowest quartile as referent. Following adjustment for confounders, we observed significant positive associations for NDEA (ORQ4 versus Q1 = 2.28, 95% CI = 1.71-3.04, Ptrend < 0.0001) and NDMA from plant sources (ORQ4 versus Q1 = 1.93, 95% CI = 1.42-2.61, Ptrend < 0.0001) with pancreatic cancer. The major food groups related to NDEA and NDMA intakes in this population were fermented cheese, pizza, grains, seafood and beer. No associations of intake of nitrate or total NOCs were observed; nitrite was inversely associated with pancreatic cancer. Although some of our findings probably reflect reverse causation bias due to lower meat intake in cases with latent disease, biologically plausible findings for pancreatic carcinogens, NDEA and NDMA, warrant further prospective investigation.

Global differences in the prevalence of the CpG island methylator phenotype of colorectal cancer

Background

CpG Island Methylator Phenotype (CIMP) is an epigenetic phenotype in CRC characterized by hypermethylation of CpG islands in promoter regions of tumor suppressor genes, leading to their transcriptional silencing and loss of function. While the prevalence of CRC differs across geographical regions, no studies have compared prevalence of CIMP-High phenotype across regions. The purpose of this project was to compare the prevalence of CIMP across geographical regions after adjusting for variations in methodologies to measure CIMP in a meta-analysis.

Methods

We searched PubMed, Medline, and Embase for articles focusing on CIMP published from 2000 to 2018. Two reviewers independently identified 111 articles to be included in final meta-analysis. We classified methods used to quantify CIMP into 4 categories: a) Classical (MINT marker) Panel group b) Weisenberg-Ogino (W-O) group c) Human Methylation Arrays group and d) Miscellaneous group. We compared the prevalence of CIMP across geographical regions after correcting for methodological variations using meta-regression techniques.

Results

The pooled prevalence of CIMP-High across all studies was 22% (95% confidence interval:21–24%; I² = 94.75%). Pooled prevalence of CIMP-H across Asia, Australia, Europe, North America and South America was 22, 21, 21, 27 and 25%, respectively. Meta-regression analysis identified no significant differences in the prevalence of CIMP-H across geographical regions after correction for methodological variations. In exploratory analysis, we observed variations in CIMP-H prevalence across countries.

Conclusion

Although no differences were found for CIMP-H prevalence across countries, further studies are needed to compare the influence of demographic, lifestyle and environmental factors in relation to the prevalence of CIMP across geographical regions.

Gut microbial diversity and genus-level differences identified in cervical cancer patients versus healthy controls

OBJECTIVES

The aim of this study was to characterize variation in the gut microbiome of women with locally advanced cervical cancer and compare it to healthy controls.

METHODS

We characterized the 16S rDNA fecal microbiome in 42 cervical cancer patients and 46 healthy female controls. Shannon diversity index (SDI) was used to evaluate alpha (within sample) diversity. Beta (between sample) diversity was examined using principle coordinate analysis (PCoA) of unweighted Unifrac distances. Relative abundance of microbial taxa was compared between samples using Linear Discriminant Analysis Effect Size (LEfSe).

RESULTS

Within cervical cancer patients, bacterial alpha diversity was positively correlated with age (p = 0.22) but exhibited an inverse relationship in control subjects (p < 0.01). Alpha diversity was significantly higher in cervical cancer patients as compared to controls (p < 0.05), though stratification by age suggested this relationship was restricted to older women (>50 years; p < 0.01). Beta diversity (unweighted Unifrac; p < 0.01) also significantly differed between cervical cancer patients and controls. Based on age- and race-adjusted LEfSe analysis, multiple taxa significantly differed between cervical cancer patients and controls. Prevotella, Porphyromonas, and Dialister were significantly enriched in cervical cancer patients, while Bacteroides, Alistipes and members of the Lachnospiracea family were significantly enriched in healthy subjects.

CONCLUSION

Our study suggests differences in gut microbiota diversity and composition between cervical cancer patients and controls. Associations within the gut microbiome by age may reflect etiologic/clinical differences. These findings provide rationale for further study of the gut microbiome in cervical cancer.

Nutrition and Cancer in the Microbiome Era

Popular views of what constitutes a healthy diet may shift, but the professional consensus is comparatively static and largely supported by our growing understanding of diet-microbiota interactions. The gut microbiome's responsiveness to diet and ability to calibrate immune and metabolic function shape new research opportunities across the cancer continuum.

Vitamin C and Vitamin E Mitigate the Risk of Pancreatic Ductal Adenocarcinoma from Meat-Derived Mutagen Exposure in Adults in a Case-Control Study

BACKGROUND

Previous studies have found that meat-derived mutagens increase, and vitamin C or E decrease, the risk of pancreatic cancer.

OBJECTIVE

The aim of this study was to determine whether intake of vitamin C or E modulates the association between meat-derived mutagen exposure and risk of pancreatic cancer.

DESIGN

We conducted a case-control study in 1321 patients with pathologically confirmed pancreatic ductal adenocarcinoma (PDAC) and 1061 healthy controls (aged 28-88 y). Cases and controls were frequency-matched by age, sex, and race/ethnicity. Mutagen intake was assessed using a meat preparation questionnaire. Intakes of vitamin C, E, and other dietary components were assessed via a food-frequency questionnaire in a subset of 811 cases and 818 controls. ORs and 95% CIs were estimated in multivariable-adjusted logistic regression models.

RESULTS

The risk of PDAC was not associated with meat intake but was associated with consumption of well-done grilled or barbecued chicken (OR: 1.57; 95% CI: 1.18, 2.09; P = 0.001). Intake of 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline was associated with increased PDAC risk (Ptrend = 0.047). Participants in the highest, as compared with the lowest, quintile of 2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline (PhIP) intake experienced a 38% increased risk of PDAC (95% CI: 1.00, 1.90; P = 0.048). Intakes of total vitamin C or E from food and supplements or from supplements alone were each inversely associated with PDAC risk. Stratified analyses showed differential associations for PhIP intake and PDAC risk, such that risk increased among individuals with lower intake of vitamin C or E and decreased among those with higher vitamin intake. Significant interactions of dietary vitamin C, dietary vitamin E, and total vitamin E with PhIP intake were detected (Pinteraction = 0.023, <0.001, and 0.013, respectively).

CONCLUSIONS

Consistent with experimental evidence, this study of 811 cases and 818 controls has shown that high intake of dietary vitamin C or E mitigates the risk of PhIP-related PDAC.

Coffee, Caffeine Metabolism Genotype and Disease Progression in Patients with Localized Prostate Cancer Managed with Active Surveillance

PURPOSE

Active surveillance is increasingly used as a management strategy for localized prostate cancer. Coffee intake has been associated with a lower prostate cancer incidence. We assessed whether coffee was associated with disease progression in men on active surveillance.

MATERIALS AND METHODS

A total of 411 patients with newly diagnosed Gleason score 6 or 7 prostate cancer were enrolled on a prospective active surveillance protocol for at least 6 months and completed a baseline dietary assessment. The active surveillance protocol included a biennial monitoring regimen with disease progression defined as an increase in the Gleason score. Cox proportional hazards models were used to evaluate associations of coffee intake with progression-free survival. We also evaluated patient genotype in the caffeine metabolism related single nucleotide polymorphism rs762551.

RESULTS

Median followup was 36 months (range 6 to 126) and the Gleason score progressed in 76 of the 411 patients (18.5%). Compared to 0 cups per day, in the multivariable model adjusting for prostate specific antigen, patient age and tumor length, less than 1 cup (HR 0.85, 95% CI 0.40-1.71), 1 to 1.9 cups (HR 0.64, 95% CI 0.29-1.43), 2 to 3.9 cups (HR 0.71, 95% CI 0.35-1.47) and 4 cups or more (HR 1.67, 95% CI 0.81-3.45) were not significantly associated with progression-free survival (p for nonlinearity = 0.01). Patients with low/moderate coffee intake and the AA fast caffeine metabolizer genotype were less likely to experience grade progression than nonconsumers (HR 0.36, 95% CI 0.15-0.88, p = 0.03).

CONCLUSIONS

Low to moderate coffee intake appears safe in men on active surveillance of localized prostate cancer. Further work is needed to determine whether high consumption is associated with shorter progression-free survival in sensitive groups.

Viewing images of alcohol use in PG-13-rated movies and alcohol initiation in Mexican-heritage youth

Mexican American adolescents report high rates of alcohol consumption as well as media use. Viewing alcohol images in the media is associated with increased alcohol consumption; however, to date, this association has not been examined across different ethnic groups in the United States. To bridge this gap, we examined the association between viewing alcohol use images in PG-13-rated movies and alcohol initiation in Mexican-heritage adolescents. A cohort of 1,154 Mexican-heritage youth, average age 14 years, was followed for 2 years; in 2008-2009, participants reported alcohol use in the past 30 days and again in 2010-2011. Exposure to alcohol use images in PG-13-rated movies was estimated from 50 movies randomly selected from a pool of 250 of the top box office hits in the United States using previously validated methods. A series of generalized linear models, adjusting for age, gender, peer and family alcohol use, family functioning, anxiety, sensation-seeking tendency, and acculturation were completed. Multiple imputation was utilized to address missing data. Overall, N = 652 participants reported no alcohol use in 2008-2009; by 2010-2011, 33.6% (n = 219) had initiated alcohol use. Adjusted models indicated an independent association between exposure to alcohol use images in PG-13-rated movies and alcohol initiation (comparing quartiles 3 to 1: RR =1.53; 95% CI [1.11, 2.10]). The findings emphasize that the relationship between viewing alcohol use scenes in American films and alcohol initiation holds among Mexican-heritage adolescents and underscore the need to limit adolescents' exposure to such powerful images in PG-13-rated movies.

Longitudinal associations of family functioning with body mass index in Mexican-origin adolescents living in the U.S

Mexican-origin adolescents have a high prevalence of obesity. Research is needed to understand how family context may shape adolescent BMI. This study examined longitudinal associations of family functioning variables with the Centers for Disease Control and Prevention's modified BMI z-score (BMIaz) in 1175 Mexican-origin adolescents, and explored interactions with acculturation. Adolescents (50% female, aged 11-13 y in 2005-06) were identified from an ongoing cohort study of Mexican-origin adults in Houston, TX, and were assessed three times from 2005-06 to 2010-11. In multivariate linear mixed models stratified by gender, we assessed longitudinal associations of family cohesion and family conflict with adolescent BMIaz and explored interactions with language acculturation. We disaggregated the between- (mean) and within-person (individual deviation) components of family cohesion and family conflict to assess the effects on BMIaz. Approximately one-third of adolescents were obese at baseline, and BMIaz declined during the study. In girls, higher mean family cohesion and conflict were associated with steeper declines in BMIaz. Parental linguistic acculturation modified the relationship between within-person deviation in family cohesion and BMIaz in girls, such that high parental U.S. acculturation was associated with a stronger inverse association. There were no significant associations in boys. These findings highlight the potential importance of the family context to female adolescent BMI and the promise of addressing family context in obesity-related interventions.

Personalized Nutrition in Disrupting Cancer - Proceedings From the 2017 American College of Nutrition Annual Meeting

Cancer is a major public health problem and is the second leading cause of death in the United States and worldwide; nearly one in six deaths are attributable to cancer. Approximately 20% of all cancers diagnosed in the United States are attributable to unhealthy diet, excessive alcohol consumption, physical inactivity, and body fatness. Individual cancers are distinct disease states that are multifactorial in their causation, making them exceedingly cumbersome to study from a nutrition standpoint. Genetic influences are a major piece of the puzzle and personalized nutrition is likely to be most effective in disrupting cancer during all stages. Increasing evidence shows that after a cancer diagnosis, continuing standard dietary recommendations may not be appropriate. This is because powerful dietary interventions such as short-term fasting and carbohydrate restriction can disrupt tumor metabolism, synergizing with standard therapies such as radiation and drug therapy to improve efficacy and ultimately, cancer survival. The importance of identifying dietary interventions cannot be overstated, and the American College of Nutrition's commitment to advancing knowledge and research is evidenced by dedication of the 2017 ACN Annual Meeting to "Disrupting Cancer: The Role of Personalized Nutrition" and this resulting proceedings manuscript, which summarizes the meeting's findings.

Association of body-mass index and outcomes in patients with metastatic melanoma treated with targeted therapy, immunotherapy, or chemotherapy: a retrospective, multicohort analysis

BACKGROUND

Obesity has been linked to increased mortality in several cancer types; however, the relation between obesity and survival outcomes in metastatic melanoma is unknown. The aim of this study was to examine the association between body-mass index (BMI) and progression-free survival or overall survival in patients with metastatic melanoma who received targeted therapy, immunotherapy, or chemotherapy.

METHODS

This retrospective study analysed independent cohorts of patients with metastatic melanoma assigned to treatment with targeted therapy, immunotherapy, or chemotherapy in randomised clinical trials and one retrospective study of patients treated with immunotherapy. Patients were classified according to BMI, following the WHO definitions, as underweight, normal, overweight, or obese. Patients without BMI and underweight patients were excluded. The primary outcomes were the associations between BMI and progression-free survival or overall survival, stratified by treatment type and sex. We did multivariable analyses in the independent cohorts, and combined adjusted hazard ratios in a mixed-effects meta-analysis to provide a precise estimate of the association between BMI and survival outcomes; heterogeneity was assessed with meta-regression analyses. Analyses were done on the predefined intention-to-treat population in the randomised controlled trials and on all patients included in the retrospective study.

FINDINGS

The six cohorts consisted of a total of 2046 patients with metastatic melanoma treated with targeted therapy, immunotherapy, or chemotherapy between Aug 8, 2006, and Jan 15, 2016. 1918 patients were included in the analysis. Two cohorts containing patients from randomised controlled trials treated with targeted therapy (dabrafenib plus trametinib [n=599] and vemurafenib plus cobimetinib [n=240]), two cohorts containing patients treated with immunotherapy (one randomised controlled trial of ipilimumab plus dacarbazine [n=207] and a retrospective cohort treated with pembrolizumab, nivolumab, or atezolizumab [n=331]), and two cohorts containing patients treated with chemotherapy (two randomised controlled trials of dacarbazine [n=320 and n=221]) were classified according to BMI as normal (694 [36%] patients), overweight (711 [37%]), or obese (513 [27%]). In the pooled analysis, obesity, compared with normal BMI, was associated with improved survival in patients with metastatic melanoma (average adjusted hazard ratio [HR] 0·77 [95% CI 0·66-0·90] for progression-free survival and 0·74 [0·58-0·95] for overall survival). The survival benefit associated with obesity was restricted to patients treated with targeted therapy (HR 0·72 [0·57-0·91] for progression-free survival and 0·60 [0·45-0·79] for overall survival) and immunotherapy (HR 0·75 [0·56-1·00] and 0·64 [0·47-0·86]). No associations were observed with chemotherapy (HR 0·87 [0·65-1·17, p_interaction=0·61] for progression-free survival and 1·03 [0·80-1·34, p_interaction=0·01] for overall survival). The association of BMI with overall survival for patients treated with targeted and immune therapies differed by sex, with inverse associations in men (HR 0·53 [0·40-0·70]), but no associations observed in women (HR 0·85 [0·61-1·18, p_interaction=0·03]).

INTERPRETATION

Our results suggest that in patients with metastatic melanoma, obesity is associated with improved progression-free survival and overall survival compared with those outcomes in patients with normal BMI, and that this association is mainly seen in male patients treated with targeted or immune therapy. These results have implications for the design of future clinical trials for patients with metastatic melanoma and the magnitude of the benefit found supports further investigation of the underlying mechanism of these associations.

FUNDING

ASCO/CCF Young Investigator Award, ASCO/CCF Career Development Award, MD Anderson Cancer Center (MDACC) Melanoma Moonshot Program, MDACC Melanoma SPORE, and the Dr Miriam and Sheldon G Adelson Medical Research Foundation.

Gut microbiome modulates response to anti-PD-1 immunotherapy in melanoma patients

Preclinical mouse models suggest that the gut microbiome modulates tumor response to checkpoint blockade immunotherapy; however, this has not been well-characterized in human cancer patients. Here we examined the oral and gut microbiome of melanoma patients undergoing anti-programmed cell death 1 protein (PD-1) immunotherapy (n = 112). Significant differences were observed in the diversity and composition of the patient gut microbiome of responders versus nonresponders. Analysis of patient fecal microbiome samples (n = 43, 30 responders, 13 nonresponders) showed significantly higher alpha diversity (P < 0.01) and relative abundance of bacteria of the Ruminococcaceae family (P < 0.01) in responding patients. Metagenomic studies revealed functional differences in gut bacteria in responders, including enrichment of anabolic pathways. Immune profiling suggested enhanced systemic and antitumor immunity in responding patients with a favorable gut microbiome as well as in germ-free mice receiving fecal transplants from responding patients. Together, these data have important implications for the treatment of melanoma patients with immune checkpoint inhibitors.

Social-demographics, health behaviors, and telomere length in the Mexican American Mano a Mano Cohort

In the current study, we examined cross-sectional associations among social-demographics, lifestyle behaviors, and relative telomere length (RTL) in peripheral blood leukocytes, as well as longitudinal relationships among major chronic diseases, weight gain, and RTL, among 12,792 Mexican Americans aged 20 to 85 years in the Mano-A-Mano, the Mexican American Cohort. As expected, RTL was inversely correlated with age (ρ=-0.15, ρ<0.001). In the multivariate analysis, we found that RTL was positively correlated with levels of education (ρ=0.021), self-insurance (ρ=0.041), body mass index (BMI) (ρ<0.001), and sleeping time per day (ρ for trend<0.001), and RTL was inversely correlated with sitting time per day (ρ for trend =0.001). In longitudinal analysis, we found that longer RTL was modestly but positively associated with increased risks of overall cancer (adjusted hazard ratio (adj.HR)=1.05, 95% conference interval (95%CI)=1.02-1.09). In quartile analysis, 4^th quartile (longest RTL) was associated with 1.53-fold increased risk of overall cancer (adj.HR=1.53, 95%CI=1.11-2.10), compared to 1^st quartile (shortest RTL). RTL was reversely associated with the risk of type-2 diabetes (adj.HR=0.89, 95%CI=0.82-0.94). In quartile analysis, 4^th quartile (longest RTL) was associated with 48% decreased risk of typle-2 diabetes (adj.HR=0.52, 95%CI=0.32-0.70), compared to 1^st quartile (shortest RTL). In addition, longer RTL was a positive predictor of at least 10% weight gain (adj.HR=1.03, 95%CI=1.00-1.05). In summary, our results in Mexican Americans support the notion that telomere length is a biological mechanism by which social demographics and health behaviors “get under the skin” to affect health.

Cohort Profile: The Mexican American Mano a Mano Cohort

Hispanic Americans comprise the largest and fastest-growing ethnic minority in the USA. In Houston, Texas, 44% of the population is of Hispanic descent, with the majority being Mexican Americans (78%). This population is under-represented in health-related research despite their high prevalence of obesity and diabetes, which may predispose them to cancer and other chronic conditions. Recognizing the need for a greater research effort into the health risks of Hispanic Americans, the population-based Mexican American (Mano a Mano) Cohort study was launched in 2001. This is an open cohort with enrolment ongoing to 2019, and as of 30 June 2014, 23 606 adult participants from over 16 600 households were enrolled. Bilingual interviewers elicit information in person on demographics, acculturation, lifestyle, occupation, medical history, family cancer history, self-reported and measured height and weight, and other exposures. Urine, blood and saliva samples have been collected at baseline from 43%, 56% and 63% of participants, respectively. DNA samples are available for about 90% of participants. Incident cancers and other chronic diseases are ascertained through annual telephone re-contact and linkage to the Texas Cancer Registry and/or medical records. Molecular data such as genetic ancestry markers, blood telomere length and HbA1c, a marker of impaired glucose tolerance, are available for a substantial proportion of the participants. Data access is provided on request [manoamano@mdanderson.org]. For further information please visit [www.mano-mano.us].

Correlates of Physical Activity Differ by Sex and Country of Birth Among Mexican-Heritage Youth

Barriers to physical activity (PA) may be experienced differently by sex and country of birth. We examine psychosocial correlates of PA in four groups based on sex (boy/girl) and country of birth [Mexico/United States (U.S.)]. 1154 Mexican heritage adolescents residing in Houston, Texas provided psychosocial data in 2008-09 and PA (number of days per week active for at least 60 min) in 2010-11 (N = 1001). Poisson regression models were fitted for each groups. Among boys, English language preference (p US-born  = 0.045, p Mexico-born  = 0.008) and higher subjective social status (p US-born  = 0.002, p Mexico-born  = 0.031) were associated with increased PA. Body image dissatisfaction was associated with decreased PA in Mexico-born girls (p = 0.007). Sensation-seeking tendencies were associated with increased PA among all groups; anxiety was associated with decreased PA among all but U.S.-born boys. Tailoring PA interventions to key sex-specific psychosocial correlates rather than country of birth may enhance efficacy of interventions to increase PA levels among Mexican heritage adolescents.

Glycemic Index, Glycemic Load, and Lung Cancer Risk in Non-Hispanic Whites

BACKGROUND

Postprandial glucose (PPG) and insulin responses play a role in carcinogenesis. We evaluated the association between dietary glycemic index (GI) and glycemic load (GL), markers of carbohydrate intake and PPG, and lung cancer risk in non-Hispanic whites.

METHODS

GL and GI were assessed among 1,905 newly diagnosed lung cancer cases recruited from the University of Texas MD Anderson Cancer Center (Houston, TX) and 2,413 healthy controls recruited at Kelsey-Seybold Clinics (Houston, TX). We assessed associations between quintiles of GI/GL and lung cancer risk and effect modification by various risk factors. ORs and 95% confidence intervals (CI) were estimated using multivariable logistic regression.

RESULTS

We observed a significant association between GI [5th vs. 1st quintile (Q) OR = 1.49; 95% CI, 1.21-1.83; P(trend) <0.001] and lung cancer risk and GI(ac) (5th vs. 1st Q OR = 1.48; 95% CI, 1.20-1.81; P(trend) = 0.001) and lung cancer risk. We observed a more pronounced association between GI and lung cancer risk among never smokers (5th vs. 1st Q OR = 2.25; 95% CI, 1.42-3.57), squamous cell carcinomas (SCC; 5th vs. 1st Q OR = 1.92; 95% CI, 1.30-2.83), and those with less than 12 years of education (5th vs. 1st Q OR = 1.75; 95% CI, 1.19-2.58, P(interaction) = 0.02).

CONCLUSION

This study suggests that dietary GI and other lung cancer risk factors may jointly and independently influence lung cancer etiology.

IMPACT

Understanding the role of GI in lung cancer could inform prevention strategies and elucidate biologic pathways related to lung cancer risk.

Mobile Phone Use and its Association With Sitting Time and Meeting Physical Activity Recommendations in a Mexican American Cohort

Background

The benefits of physical activity (PA) are well-documented. Mobile phones influence PA by promoting screen-based sedentary time, providing prompts or reminders to be active, aiding in tracking and monitoring PA, or providing entertainment during PA. It is not known how mobile phone use is associated with PA and sitting time in Mexican Americans, and how mobile phone users may differ from nonusers.

Objective

To determine the associations between mobile phone use, PA, and sitting time and how these behaviors differ from mobile phone nonusers in a sample of 2982 Mexican-American adults from the Mano a Mano cohort.

Methods

Differences in meeting PA recommendations and sitting time between mobile phone users and nonusers were examined using chi-square and analysis of variance tests. Logistic regression was used to examine associations between mobile phone use, PA, and sitting.

Results

Mobile phone users were more likely to be obese by body mass index criteria (≥30 kg/m²), younger, born in the United States and lived there longer, more educated, and sit more hours per day but more likely to meet PA recommendations than nonusers. Males (odds ratio [OR] 1.42, 95% CI 1.16-1.74), use of text messaging (OR 1.26, 95% CI 1.03-1.56), and having a higher acculturation score (OR 1.27, 95% CI 1.07-1.52) were associated with higher odds of meeting PA recommendations. Sitting more hours per day was associated with being male, obese, born in the United States, a former alcohol drinker, and having at least a high school education. Among nonusers, being born in the United States was associated with higher odds of more sitting time, and being married was associated with higher odds of meeting PA recommendations.

Conclusions

Mobile phone interventions using text messages could be tailored to promote PA in less acculturated and female Mexican American mobile phone users.

Acculturation and Diabetes Risk in the Mexican American Mano a Mano Cohort

OBJECTIVES

To investigate the association between acculturation and diabetes risk in the Mexican American Mano a Mano (hand to hand) Cohort.

METHODS

We recruited 15 975 men and women in the Houston, Texas, area from 2001 to 2014. We used language use, birth country, and duration of US residence (among Mexico-born) to assess acculturation. Participants self-reported a physician's diagnosis of diabetes during annual follow-up over an average of 5.4 (range = 1-13) years. Self-reported diabetes status was validated in medical records for a subset of 235 participants with 98% agreement.

RESULTS

Diabetes risk was higher among immigrants with 15 to 19, 20 to 24, and 25 or more years (relative risk = 1.47; 95% confidence interval = 1.07, 2.01) of US residence, relative to those with less than 5 years. Neither language acculturation nor birth country was significantly associated with diabetes risk.

CONCLUSIONS

Among participants born in Mexico, diabetes risk increased with longer duration of US residence.

Severe obesity prior to diagnosis limits survival in colorectal cancer patients evaluated at a large cancer centre

Background:

In contrast to the consistent evidence for obesity and colorectal cancer (CRC) risk, the impact of obesity in CRC patients is less clear. In a well-characterised cohort of CRC patients, we prospectively evaluated class I and class II obesity with survival outcomes.

Methods:

The CRC patients (N=634) were followed from the date of diagnosis until disease progression/first recurrence (progression-free survival (PFS)) or death (overall survival (OS)). Body mass index (BMI) was calculated from reported usual weight prior to diagnosis. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated in models adjusted for clinicopathologic, treatment, and lifestyle factors.

Results:

Over a median follow-up of 4 years, 208 (33%) patients died and 235 (37%) recurred or progressed. Class II obesity, as compared with either overweight or normal weight, was associated with an increased risk of death (HR and 95% CI: 1.55 (0.97–2.48) and 1.65 (1.02–2.68), respectively), but no clear association was observed with PFS. In analyses restricted to patients who presented as stages I–III, who reported stable weight, or who were aged <50 years, obesity was associated with a significant two- to five-fold increased risk of death.

Conclusions:

In CRC patients evaluated at a large cancer centre, severely obese patients experienced worse survival outcomes independent of many other factors.