Premorbid Obesity and Mortality in Patients With Pancreatic Cancer: A Systematic Review and Meta-analysis

Global disparities in the burden of pancreatic cancer (1990-2021): insights from the 2021 Global Burden of Disease study

BACKGROUND

Pancreatic cancer (PC) is a highly lethal malignancy, ranking seventh among cancer-related deaths worldwide. This study utilizes data from the 2021 Global Burden of Disease (GBD) study to examine the global burden of PC and associated health inequalities from 1990 to 2021, with a focus on key risk factors such as obesity, high fasting plasma glucose, and the Socio-Demographic Index (SDI).

METHODS

Disability-Adjusted Life Years (DALYs) for PC were estimated using GBD 2021 data. The analysis incorporated SDI, age, gender, and major risk factors, including obesity and high fasting plasma glucose. Descriptive statistics and visualizations, such as age-sex pyramids and geographic maps, were employed to assess global, regional, and national burdens. Health disparities were quantified using the Concentration Index (CI) and the Slope Index of Inequality (SII), with CI assessing relative health distribution by income and SII measuring absolute socioeconomic inequality.

RESULTS

Globally, PC-related DALYs rose from 1.76 million in 1990 to 4.25 million in 2021 (141.48% increase), with the age-standardized DALY rate up 11.57% to 48.71 (95% UI 23.43 to 74.33). The burden was highest in high SDI regions, while low SDI areas still faced elevated rates; transitional and developing economies showed the highest age-standardized DALY rates. The SII increased from 189.63 (95% CI 177.65 to 245.17) in 1990 to 321.17 (95% CI 294.48 to 379.722) in 2021, indicating widening socioeconomic disparities.

CONCLUSION

PC remains a significant global health challenge with growing socioeconomic and geographic disparities. Urgent action is needed to address modifiable risk factors (e.g., obesity, diabetes) through enhanced healthcare infrastructure, early detection, and treatment access in low SDI countries, alongside improved data systems and international collaboration.

Beneath the Surface: The Emerging Role of Ultra-Processed Foods in Obesity-Related Cancer

PURPOSEOF REVIEW

Ultra-processed foods (UPFs) are becoming more and more important in daily diets around the world; in some cases, they can account for as much as 60% of daily energy intake. Epidemiological evidence suggests that this shift toward high levels of food processing may be partially responsible for the global obesity epidemic and the rise in the prevalence of chronic diseases.

RECENT FINDINGS

Few prospective studies have examined the relationship between UPF consumption and cancer outcomes. According to currently available information, UPFs may increase the risk of cancer due to their obesogenic properties and exposure to substances that can cause cancer, such as certain food additives and pollution from product processing. The complex relationship between obesity and cancer involves factors such as immune dysregulation, altered adipokine and sex hormone levels, abnormal fatty acid metabolism, extracellular matrix remodeling, and chronic inflammation. Addressing cancer risk associated with UPF consumption could involve a multifaceted approach, including consumer behavior modification programs and robust public health regulations aimed at enhancing food environments. Improved knowledge of the potential dual negative impacts of UPFs on the environment and cancer risk is one of the priority areas we identify for future research and policy implications. Various approaches could be used to prevent cancers associated with UPF consumption, such as consumer behavior change programs and stricter public health regulations needed to improve the food environment. This review examines for the first time the potential role of UPFs in cancer risk associated with obesity, exploring underlying biological mechanisms and identifying key areas for future research and policy action, including the dual environmental and health impact of UPFs.

Underweight as a Risk Factor for Major Intra-abdominal Malignancy Surgeries

Purpose The relationship between body mass index (BMI) and postoperative outcomes for oncology surgeries among the Asian population remains controversial. A prevailing perception suggests that excess adiposity is associated with reduced cancer survival. However, several reports have shown that overweight or early obese states confer better survival outcomes. It is hypothesized that patients with better nutrition and surplus calories grant survival advantages to radical cancer treatment. The purpose of this study is to examine the relationship between BMI and postoperative 30-day and one-year mortality in the Asian population. Methods This retrospective review investigates the postoperative mortality, intensive care unit (ICU) admission, and length of hospital stay following major abdominal cancer surgeries within the Asian population. Patients were stratified into three groups based on their BMI: underweight (BMI < 18.5 kg/m2), normal weight (BMI 18.5-27.5 kg/m2), and obese (BMI > 27.5 kg/m2). Results A total of 646 patients were included in this study. At 30 days, the underweight group presents an 8% mortality compared to 1% and 3% mortality in the normal BMI and obese groups, respectively. At one year, the low BMI group presents a significant increase in mortality of 53% as opposed to the normal BMI and obese group with mortality rates of 14% and 12%, respectively (p < 0.001). There is a significant increase in the ICU admission rate in the underweight group (n = 13, 25%) compared to the normal BMI and obese groups (n = 26, 6%; n = 8, 6% p < 0.001). Similarly, the group with lower BMI was observed to require a longer hospital stay postoperatively (median (IQR) 11.0 (4.0-24.0)) compared to the normal (median (IQR) 4.0 (3.0-9.0)) and obese (median (IQR) 4.5 (3.0-8.0)) patients. Conclusion Concordant results were observed in the underweight patient group with increased one-year mortality, ICU admission rate, and hospital stay postoperatively. Low BMI presents as an independent risk factor for major radical surgeries.

Physical Activity Decreases Inflammation and Delays the Development of Obesity-Associated Pancreatic Ductal Adenocarcinoma

Obesity is a risk factor for pancreatic ductal adenocarcinoma (PDAC), a deadly disease with limited preventive strategies. Lifestyle interventions to decrease obesity represent a potential approach to prevent obesity-associated PDAC. In this study, we examined whether decreasing obesity through physical activity (PA) and/or dietary changes could decrease inflammation in humans and prevent obesity-associated PDAC in mice. Comparison of circulating inflammatory-associated cytokines in subjects (overweight and obese) before and after a PA intervention revealed PA lowered systemic inflammatory cytokines. Mice with pancreatic-specific inducible KrasG12D expression were exposed to PA and/or dietary interventions during and after obesity-associated cancer initiation. In mice with concurrent diet-induced obesity and KrasG12D expression, the PA intervention led to lower weight gain, suppressed systemic inflammation, delayed tumor progression, and decreased proinflammatory signals in the adipose tissue. However, these benefits were not as evident when obesity preceded pancreatic KrasG12D expression. Combining PA with diet-induced weight loss (DI-WL) delayed obesity-associated PDAC progression in the genetically engineered mouse model, but neither PA alone nor combined with DI-WL or chemotherapy prevented PDAC tumor growth in orthotopic PDAC models regardless of obesity status. PA led to the upregulation of Il15ra in adipose tissue. Adipose-specific overexpression of Il15 slowed PDAC growth but only in nonobese mice. Overall, our study suggests that PA alone or combined with DI-WL can reduce inflammation and delay obesity-associated PDAC development or progression. Lifestyle interventions that prevent or manage obesity or therapies that target weight loss-related molecular pathways could prevent progression of PDAC. Significance: Physical activity reduces inflammation and induces changes to adipose-related signaling to suppress pancreatic cancer, supporting the potential of obesity management strategies to reduce the risk of developing pancreatic cancer. See related commentary by Sogunro and Muzumdar, p. 2935.

Body mass index and survival among patients with advanced biliary tract cancer: a single-institutional study with nationwide data-based validation

BACKGROUND

Excess body weight may modulate the progression of various cancer types. The prognostic relevance of body mass index (BMI) has not been fully examined in patients with biliary tract cancer.

METHODS

Using a single-institutional cohort of 360 patients receiving gemcitabine-based chemotherapy for advanced biliary tract cancer, we examined the association of BMI with overall survival (OS). Using the Cox regression model with adjustment for potential confounders, we calculated hazard ratios (HRs) and 95% confidence intervals (CIs) for OS according to BMI. The findings were validated using a Japanese nationwide inpatient database including 8324 patients treated at 201 hospitals.

RESULTS

In the clinical cohort, BMI was not associated with OS (Ptrend = 0.34). Compared to patients with BMI = 18.5-24.9 kg/m2, patients with BMI < 18.5 kg/m2 and ≥ 25.0 kg/m2 had adjusted HRs for OS of 1.06 (95% CI, 0.78-1.45) and 1.01 (95% CI, 0.74-1.39), respectively. There was no evidence on a non-linear relationship between BMI and OS (Pnonlinearity = 0.63). In the nationwide cohort, the null findings were validated (Ptrend = 0.18) with adjusted HRs of 1.07 (95% CI, 0.98-1.18) for BMI < 18.5 kg/m2 and 1.05 (95% CI, 0.96-1.14) for BMI ≥ 25.0 kg/m2 (vs. BMI = 18.5-24.9 kg/m2). In the clinical cohort, BMI was not associated with progression-free survival (Ptrend = 0.81).

CONCLUSIONS

BMI was not associated with survival outcomes of patients with advanced biliary tract cancer. Further research is warranted incorporating more detailed body composition metrics to explore the prognostic role of adiposity in biliary tract cancer.

Extracellular vesicles in tumor-adipose tissue crosstalk: key drivers and therapeutic targets in cancer cachexia

Cancer cachexia is a complex metabolic syndrome characterized by unintentional loss of skeletal muscle and body fat. This syndrome is frequently associated with different types of cancer and negatively affects the prognosis and outcome of these patients. It involves a dynamic interplay between tumor cells and adipose tissue, where tumor-derived extracellular vesicles (EVs) play a crucial role in mediating intercellular communication. Tumor cells release EVs containing bioactive molecules such as hormones (adrenomedullin, PTHrP), pro-inflammatory cytokines (IL-6), and miRNAs (miR-1304-3p, miR-204-5p, miR-155, miR-425-3p, miR-146b-5p, miR-92a-3p), which can trigger lipolysis and induce the browning of white adipocytes contributing to a cancer cachexia phenotype. On the other hand, adipocyte-derived EVs can reprogram the metabolism of tumor cells by transporting fatty acids and enzymes involved in fatty acid oxidation, resulting in tumor growth and progression. These vesicles also carry leptin and key miRNAs (miR-155-5p, miR-10a-3p, miR-30a-3p, miR-32a/b, miR-21), thereby supporting tumor cell proliferation, metastasis formation, and therapy resistance. Understanding the intricate network underlying EV-mediated communication between tumor cells and adipocytes can provide critical insights into the mechanisms driving cancer cachexia. This review consolidates current knowledge on the crosstalk between tumor cells and adipose tissue mediated by EVs and offers valuable insights for future research. It also addresses controversial topics in the field and possible therapeutic approaches to manage cancer cachexia and ultimately improve patient outcomes and quality of life.

Body mass index, weight change, and cancer prognosis: a meta-analysis and systematic review of 73 cohort studies

BACKGROUND

Identifying the association between body mass index (BMI) or weight change and cancer prognosis is essential for the development of effective cancer treatments. We aimed to assess the strength and validity of the evidence of the association between BMI or weight change and cancer prognosis by a systematic evaluation and meta-analysis of relevant cohort studies.

METHODS

We systematically searched the PubMed, Web of Science, EconLit, Embase, Food Sciences and Technology Abstracts, PsycINFO, and Cochrane databases for literature published up to July 2023. Inclusion criteria were cohort studies with BMI or weight change as an exposure factor, cancer as a diagnostic outcome, and data type as an unadjusted hazard ratio (HR) or headcount ratio. Random- or fixed-effects models were used to calculate the pooled HR along with the 95% confidence interval (CI).

RESULTS

Seventy-three cohort studies were included in the meta-analysis. Compared with normal weight, overweight or obesity was a risk factor for overall survival (OS) in patients with breast cancer (HR 1.37, 95% CI 1.22-1.53; P < 0.0001), while obesity was a protective factor for OS in patients with gastrointestinal tumors (HR 0.67, 95% CI 0.56-0.80; P < 0.0001) and lung cancer (HR 0.67, 95% CI 0.48-0.92; P = 0.01) compared with patients without obesity. Compared with normal weight, underweight was a risk factor for OS in patients with breast cancer (HR 1.15, 95% CI 0.98-1.35; P = 0.08), gastrointestinal tumors (HR 1.54, 95% CI 1.32-1.80; P < 0.0001), and lung cancer (HR 1.28, 95% CI 1.22-1.35; P < 0.0001). Compared with nonweight change, weight loss was a risk factor for OS in patients with gastrointestinal cancer.

CONCLUSIONS

Based on the results of the meta-analysis, we concluded that BMI, weight change, and tumor prognosis were significantly correlated. These findings may provide a more reliable argument for the development of more effective oncology treatment protocols.

Association between triglyceride glucose index and total bone mineral density: a cross-sectional study from NHANES 2011-2018

The Homeostatic Model Assessment for Triglyceride Glucose Index (TyG) and its related indices, including triglyceride glucose-waist circumference (TyG-WC), triglyceride glucose-waist-to-height ratio (TyG-WHtR) and triglyceride glucose-body mass index (TyG-BMI), has emerged as a practical tool for assessing insulin resistance in metabolic disorders. However, limited studies have explored the connection between TyG, TyG-related indices and osteoporosis. This population-based study, utilizing data from the National Health and Nutrition Examination Survey 2011-2018, involved 5456 participants. Through weighted multivariate linear regression and smoothed curve fitting, a significant positive correlation was found between TyG, TyG-related indices and total bone mineral density (BMD) after adjusting for covariates [β = 0.0124, 95% CI (0.0006, 0.0242), P = 0.0390; β = 0.0004, 95% CI (0.0003, 0.0004), P < 0.0001; β = 0.0116, 95% CI (0.0076, 0.0156), P < 0.0001; β = 0.0001, 95% CI (0.0001, 0.0001), P < 0.0001]. In subgroup analysis, race stratification significantly affected the relationship between TyG and total BMD. Additionally, gender and race were both significant for TyG-related indices. Non-linear relationships and threshold effects with inflection points at 9.106, 193.9265, 4.065, and 667.5304 (TyG, TyG-BMI, TyG-WHtR, TyG-WC) were identified. Saturation phenomena were observed between TyG-BMI, TyG-WC and total BMD with saturation thresholds at 314.177 and 1022.0428. These findings contributed to understanding the association between TyG, TyG-related indices and total BMD, offering insights for osteoporosis prevention and treatment.

Risk reduction of non-hormonal cancers following bariatric surgery

Metabolic and bariatric surgery (MBS) is the most effective intervention for weight loss leading to significant resolution of obesity-related medical conditions. Recent literature has demonstrated risk reduction of certain cancer types after MBS. Studies have shown an overall reduction in the risk of hormonal cancer, such as breast and endometrial cancer. However, the association between bariatric surgery and the incidence of various types of non-hormonal cancer such as esophageal, gastric, liver, gallbladder, colorectal, pancreatic and kidney cancer remains contested. The aim of this study was to highlight obesity and its relationship to cancer development as well as bariatric surgery and its role in cancer reduction with focus on non-hormonal cancers.

Metabolic Risk Factors and Their Impact on Quality of Life in Patients with Pancreatic Cancer, Acute or Exacerbated Chronic Pancreatitis

Аim: to evaluate metabolic risk factors and their impact on quality of life in patients with pancreatic cancer (PC) and in patients with acute or exacerbated chronic pancreatitis.

Materials and methods. Forty-five patients with PC (group 1) and 141 patients with acute pancreatitis or exacerbated chronic pancreatitis (group 2) in an observational multicenter clinical cross-sectional uncontrolled study were examined. Clinical, laboratory and instrumental examination of patients and assessment of risk factors (lipid profile, blood plasma glucose, obesity, arterial hypertension) were carried out in accordance with clinical recommendations. Patients completed the SF-36 questionnaire once to assess quality of life at hospital admission before treatment.

Results. In group 1, indicators of total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C) in blood serum (3.7 ± 0.2; 2.2 ± 0.2 and 0.8 ± 0.1 mmol/L) were lower than in group 2 (5.1 ± 0.1; 3.1 ± 0.1 and 1.2 ± 0.1 mmol/L; p < 0.05). Arterial hypertension was more common in group 1 (55.6 %) than in group 2 (34.8 %; p = 0.013). The presence of arterial hypertension increases the chance of having PC by 2.7 times (p < 0.05). Body mass index parameters, including obesity, as well as parameters of triglycerides, and fasting plasma glucose, did not differ between the groups. Logistic regression analysis revealed a direct relationship with PC HDL hypocholesterolemia (Exp B = 4.976; p < 0.001) and arterial hypertension (Exp B = 2.742; p = 0.027) and an inverse relationship — with hypercholesterolemia (Exp B = 0.204; p = 0.002). The chance of having PC was not associated with age, fasting plasma glucose ³ 7.0 mmol/L, obesity. Quality of life indicators were higher in group 1 than in group 2 on four SF-36 scales: bodily pain (68.1 ± 5.1 and 36.8 ± 2.0; p < 0.001), general health (51.1 ± 2.5 and 38.0 ± 1.7 points; p < 0.001), social functioning (74.7 ± 3.0 and 64.5 ± 2.2 points; p = 0.007), role emotional functioning (28.2 ± 5.2 and 12.5 ± 3.1 points; p = 0.007) and in the general domain “physical component of health” (40.2 ± 1.0 and 33.6 ± 0.8 points; p < 0.001). In group 1 with HDL hypocholesterolemia compared with its absence, the indicators of role emotional functioning (22.2 ± 5.1 and 51.9 ± 13.7 points; p = 0.020) were lower, with arterial hypertension compared with its absence — role physical functioning (5.0 ± 4.0 and 25.5 ± 7.5 points; p = 0.036) and role emotional functioning (16.0 ± 5.1 and 43.3 ± 8.8 points; p = 0.007) were lower.

Conclusions. In patients with PC arterial hypertension was more common and the levels of total cholesterol, LDL-C and HDL-C were lower than in patients with acute or exacerbated chronic pancreatitis. The chance of having PC is directly associated with HDL hypocholesterolemia, with arterial hypertension, inversely — with hypercholesterolemia, and is not associated with age, fasting plasma glucose ³ 7 mmol/L, or obesity. In patients with PC, quality of life indicators were higher on four SF-36 scales and on the general domain “physical component of health” than in the group with acute or exacerbated chronic pancreatitis. In patients with PC metabolic factors significantly worsened self-assessment of quality of life in terms of role functioning; in patients with acute or exacerbated chronic pancreatitis there was no such association.

Efficacy and Safety of Chemotherapy in Elderly Patients with Unresectable Pancreatic Cancer

BACKGROUND/AIMS

The incidence of pancreatic cancer (PC) is gradually increasing among elderly individuals, but there are insufficient clinical data on elderly individuals. To determine the efficacy and safety of chemotherapy, we compared the. the outcomes of elderly patients with unresectable PC.

METHODS

We enrolled patients aged 75 years or older diagnosed with PC from 1 January 2010 to 30 November 2021. Propensity score matching (PSM) was used to reduce the heterogeneity of the study population. For efficacy evaluation, the median overall survival (OS) was estimated for the chemotherapy and nonchemotherapy groups. Chemotherapy tolerability evaluations were also investigated.

RESULTS

The study included 115 patients, 47 of whom received chemotherapy and 68 who did not. After PSM, compared with the nonchemotherapy group, the chemotherapy group had more myocardial infarctions (14.6 vs. 0.0%, p < 0.001) and chronic obstructive pulmonary disease (4.4 vs. 0.0%, p = 0.043). The primary endpoint, median OS, was significantly different in the with vs. without chemotherapy groups (203 vs. 106 days, p = 0.013). In the chemotherapy group, 10 patients (21.3%) discontinued treatment due to adverse events. However, there were no reports of death due to severe adverse events.

CONCLUSIONS

This study demonstrated that chemotherapy improved median OS among elderly patients. These data could support the use of chemotherapy for elderly patients with unresectable PC.

Mechanisms of obesity- and diabetes mellitus-related pancreatic carcinogenesis: a comprehensive and systematic review

Research on obesity- and diabetes mellitus (DM)-related carcinogenesis has expanded exponentially since these two diseases were recognized as important risk factors for cancers. The growing interest in this area is prominently actuated by the increasing obesity and DM prevalence, which is partially responsible for the slight but constant increase in pancreatic cancer (PC) occurrence. PC is a highly lethal malignancy characterized by its insidious symptoms, delayed diagnosis, and devastating prognosis. The intricate process of obesity and DM promoting pancreatic carcinogenesis involves their local impact on the pancreas and concurrent whole-body systemic changes that are suitable for cancer initiation. The main mechanisms involved in this process include the excessive accumulation of various nutrients and metabolites promoting carcinogenesis directly while also aggravating mutagenic and carcinogenic metabolic disorders by affecting multiple pathways. Detrimental alterations in gastrointestinal and sex hormone levels and microbiome dysfunction further compromise immunometabolic regulation and contribute to the establishment of an immunosuppressive tumor microenvironment (TME) for carcinogenesis, which can be exacerbated by several crucial pathophysiological processes and TME components, such as autophagy, endoplasmic reticulum stress, oxidative stress, epithelial-mesenchymal transition, and exosome secretion. This review provides a comprehensive and critical analysis of the immunometabolic mechanisms of obesity- and DM-related pancreatic carcinogenesis and dissects how metabolic disorders impair anticancer immunity and influence pathophysiological processes to favor cancer initiation.

Obesity and Cancer: A Current Overview of Epidemiology, Pathogenesis, Outcomes, and Management

BACKGROUND

Obesity or excess body fat is a major global health challenge that has not only been associated with diabetes mellitus and cardiovascular disease but is also a major risk factor for the development of and mortality related to a subgroup of cancer. This review focuses on epidemiology, the relationship between obesity and the risk associated with the development and recurrence of cancer and the management of obesity.

METHODS

A literature search using PubMed and Google Scholar was performed and the keywords 'obesity' and cancer' were used. The search was limited to research papers published in English prior to September 2022 and focused on studies that investigated epidemiology, the pathogenesis of cancer, cancer incidence and the risk of recurrence, and the management of obesity.

RESULTS

About 4-8% of all cancers are attributed to obesity. Obesity is a risk factor for several major cancers, including post-menopausal breast, colorectal, endometrial, kidney, esophageal, pancreatic, liver, and gallbladder cancer. Excess body fat results in an approximately 17% increased risk of cancer-specific mortality. The relationship between obesity and the risk associated with the development of cancer and its recurrence is not fully understood and involves altered fatty acid metabolism, extracellular matrix remodeling, the secretion of adipokines and anabolic and sex hormones, immune dysregulation, and chronic inflammation. Obesity may also increase treatment-related adverse effects and influence treatment decisions regarding specific types of cancer therapy. Structured exercise in combination with dietary support and behavior therapy are effective interventions. Treatment with glucagon-like peptide-1 analogues and bariatric surgery result in more rapid weight loss and can be considered in selected cancer survivors.

CONCLUSIONS

Obesity increases cancer risk and mortality. Weight-reducing strategies in obesity-associated cancers are important interventions as a key component of cancer care. Future studies are warranted to further elucidate the complex relationship between obesity and cancer with the identification of targets for effective interventions.

Low preoperative skeletal muscle index increases the risk of mortality among resectable pancreatic cancer patients: A retrospective study

BACKGROUND

The only potential curative treatment for patients with pancreatic cancer is surgery; however, the prognosis remains poor. Measures of body composition based on computed tomography (CT) have been established as a reliable predictor of the prognosis of cancer patients after surgery.

AIM

To elucidate the associations of body composition measures derived from preoperative CT scans with the prognosis of patients with pancreatic cancer.

METHODS

One hundred fifteen patients undergoing pancreatic resection with curative intent for pancreatic cancer were retrospectively enrolled. A preoperative CT scan at the third lumbar vertebral level was performed to measure the skeletal muscle index (SMI), mean skeletal muscle radiodensity, subcutaneous adipose tissue index, and visceral to subcutaneous adipose tissue area ratio. The clinical and pathological data were collected. The effects of these factors on long-term survival were evaluated.

RESULTS

Among the five body composition measures, only low SMI independently predicted overall survival (OS) [hazard ratio (HR): 2.307; 95% confidence interval (CI): 1.210-4.402] and recurrence-free survival (HR: 1.907; 95%CI: 1.147-3.171). Furthermore, patients with low SMI (vs high SMI) were older (68.8 ± 9.3 years vs 63.3 ± 8.4 years); low SMI was present in 27 of 56 patients (48.2%) aged 65 years and older and in 11 of 59 younger patients (18.6%). In addition, subgroup analyses revealed that the correlation between low SMI and OS was observed only in patients aged 65 years and older.

CONCLUSION

Low preoperative SMI was more prevalent in elderly patients and was associated with a poor prognosis among pancreatic cancer patients, especially elderly patients.

Adiposity and cancer survival: a systematic review and meta-analysis

PURPOSE

The increasing availability of clinical imaging tests (especially CT and MRI) that directly quantify adipose tissue has led to a rapid increase in studies examining the relationship of visceral, subcutaneous, and overall adiposity to cancer survival. To summarize this emerging body of literature, we conducted a systematic review and meta-analysis of imaging-measured as well as anthropometric proxies for adipose tissue distribution and cancer survival across a wide range of cancer types.

METHODS

Using keywords related to adiposity, cancer, and survival, we conducted a systematic search of the literature in PubMed and MEDLINE, Embase, and Web of Science Core Collection databases from database inception to 30 June 2021. We used a random-effect method to calculate pooled hazard ratios (HR) and corresponding 95% confidence intervals (CI) within each cancer type and tested for heterogeneity using Cochran's Q test and the I2 test.

RESULTS

We included 203 records for this review, of which 128 records were utilized for quantitative analysis among 10 cancer types: breast, colorectal, gastroesophageal, head and neck, hepatocellular carcinoma, lung, ovarian, pancreatic, prostate, and renal cancer. We found that imaging-measured visceral, subcutaneous, and total adiposity were not significantly associated with increased risk of overall mortality, death from primary cancer, or cancer progression among patients diagnosed with these 10 cancer types; however, we found significant or high heterogeneity for many cancer types. For example, heterogeneity was similarly high when the pooled HRs (95% CI) for overall mortality associated with visceral adiposity were essentially null as in 1.03 (0.55, 1.92; I2 = 58%) for breast, 0.99 (0.81, 1.21; I2 = 71%) for colorectal, versus when they demonstrated a potential increased risk 1.17 (0.85, 1.60; I2 = 78%) for hepatocellular carcinoma and 1.62 (0.90, 2.95; I2 = 84%) for renal cancer.

CONCLUSION

Greater adiposity at diagnosis (directly measured by imaging) is not associated with worse survival among cancer survivors. However, heterogeneity and other potential limitations were noted across studies, suggesting differences in study design and adiposity measurement approaches, making interpretation of meta-analyses challenging. Future work to standardize imaging measurements and data analyses will strengthen research on the role of adiposity in cancer survival.

Healthcare vulnerability disparities in pancreatic cancer treatment and mortality using the Korean National Sample Cohort: a retrospective cohort study

Background

The gap in treatment and health outcomes after diagnosis of pancreatic cancer is a major public health concern. We aimed to investigate the differences in the health outcomes and treatment of pancreatic cancer patients in healthcare vulnerable and non-vulnerable areas.

Methods

This retrospective cohort study evaluated data from the Korea National Health Insurance Corporation-National Sample Cohort from 2002 to 2019. The position value for relative comparison index was used to define healthcare vulnerable areas. Cox proportional hazard regression was used to estimate the risk of mortality in pancreatic cancer patients according to healthcare vulnerable areas, and multiple logistic regression was used to estimate the difference in treatment.

Results

Among 1,975 patients, 279 (14.1%) and 1,696 (85.9%) lived in the healthcare vulnerable and non-vulnerable areas, respectively. Compared with the non-vulnerable area, pancreatic cancer patients in the vulnerable area had a higher risk of death at 3 months (hazard ratio [HR]: 1.33, 95% confidence interval [CI] = 1.06–1.67) and 6 months (HR: 1.23, 95% CI = 1.03–1.48). In addition, patients with pancreatic cancer in the vulnerable area were less likely to receive treatment than patients in the non-vulnerable area (odds ratio [OR]: 0.70, 95% CI = 0.52–0.94). This trend was further emphasized for chemotherapy (OR: 0.68, 95% CI = 0.48–0.95).

Conclusion

Patients with pancreatic cancer belonging to medically disadvantaged areas receive less treatment and have a higher risk of death. This may be a result of the late diagnosis of pancreatic cancer among these patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-10027-2.

Obesity and Pancreatic Cancer: Recent Progress in Epidemiology, Mechanisms and Bariatric Surgery

More than 30% of people in the United States (US) are classified as obese, and over 50% are considered significantly overweight. Importantly, obesity is a risk factor not only for the development of metabolic syndrome but also for many cancers, including pancreatic ductal adenocarcinoma (PDAC). PDAC is the third leading cause of cancer-related death, and 5-year survival of PDAC remains around 9% in the U.S. Obesity is a known risk factor for PDAC. Metabolic control and bariatric surgery, which is an effective treatment for severe obesity and allows massive weight loss, have been shown to reduce the risk of PDAC. It is therefore clear that elucidating the connection between obesity and PDAC is important for the identification of a novel marker and/or intervention point for obesity-related PDAC risk. In this review, we discussed recent progress in obesity-related PDAC in epidemiology, mechanisms, and potential cancer prevention effects of interventions, including bariatric surgery with preclinical and clinical studies.

Expected and paradoxical effects of obesity on cancer treatment response

Obesity, whose prevalence is pandemic and continuing to increase, is a major preventable and modifiable risk factor for diabetes and cardiovascular diseases, as well as for cancer. Furthermore, epidemiological studies have shown that obesity is a negative independent prognostic factor for several oncological outcomes, including overall and cancer-specific survival, for several site-specific cancers as well as for all cancers combined. Yet, a recently growing body of evidence suggests that sometimes overweight and obesity may associate with better outcomes, and that immunotherapy may show improved response among obese patients compared with patients with a normal weight. The so-called 'obesity paradox' has been reported in several advanced cancer as well as in other diseases, albeit the mechanisms behind this unexpected relationship are still not clear. Aim of this review is to explore the expected as well as the paradoxical relationship between obesity and cancer prognosis, with a particular emphasis on the effects of cancer therapies in obese people.

The Saturation Effect of Body Mass Index on Bone Mineral Density for People Over 50 Years Old: A Cross-Sectional Study of the US Population

Background: Previous studies had revealed that Body Mass Index (BMI) positively affected Bone Mineral Density (BMD). However, an excessively high BMI was detrimental to health, especially for the elderly. Moreover, it was elusive how much BMI was most beneficial for BMD in older adults to maintain.

Objective: To investigate whether there was a BMI saturation effect value that existed to maintain optimal BMD.

Methods: A cross-sectional study was conducted using the datasets of the National Health and Nutrition Examination Survey (NHANES) 2005–2006, 2007–2008, 2009–2010, 2013–2014, and 2017–2018. After adjusting for covariates, an analysis of the association between BMI and BMD in different femoral regions (Total femur, Femoral neck, Trochanter, Intertrochanter, and Ward's triangle) and lumbar spine regions (Total spine, L1, L2, L3, and L4) in the whole population was performed using the multivariate linear regression models, smoothing curve fitting, and saturation effects analysis models. Then, subgroup analyses were performed according to gender, age, and race.

Results: A total of 10,910 participants (5,654 males and 5,256 females) over 50 years were enrolled in this population-based study. Multivariate linear regression analyses in the population older than 50 years showed that BMI was positively associated with femoral BMD and lumbar spine BMD (P < 0.001, respectively). Smoothing curve fitting showed that the relationship between BMI and BMD was not simply linear and that a saturation value existed. The saturation effect analysis showed that the BMI saturation value was 26.13 (kg/m²) in the total femur, 26.82 (kg/m²) in the total spine, and showed site-specificity in L1 (31.90 kg/m²) and L2 (30.89 kg/m²). The saturation values were consistent with the whole participants in males, while there was high variability in the females. BMI saturation values remained present in subgroup analyses by age and race, showing specificity in some age (60–70 years old) groups and in some races.

Conclusions: Our study showed a saturation value association between BMI and BMD for people over 50 years old. Keeping the BMI in the slightly overweight value (around 26 kg/m²) might reduce other adverse effects while obtaining optimal BMD.

[Obesity and Pancreatobiliary Disease]

Obesity has become a major medical and public health problem worldwide. Recent studies have shown that obesity is a chronic disease that is associated with many diseases, such as gallstone disease, acute pancreatitis, fatty liver, and digestive cancer. Obesity is also a risk factor for the formation of cholesterol gallstones. Clinical and epidemiological studies have suggested that obesity is positively associated with the risk of gallbladder cancer. Obesity may modulate the lipid and endogenous hormones metabolism, affect gallbladder motility, increase the risk of gallstones, and increased the risk of gallbladder cancer. In addition, obesity has been considered a risk factor for pancreatic diseases, including pancreatitis and pancreatic cancer. Obese patients develop systemic and local complications of acute pancreatitis more frequently. Several epidemiologic studies have suggested an association of pancreatic cancer with high body mass and lack of physical activity. This study reviewed the literature on obesity and pancreatobiliary disease in terms of epidemiology and mechanism.

Gender Differences in Obesity-Related Cancers

PURPOSE OF REVIEW

In this review, we summarize the role of obesity in carcinogenesis, providing details on specific cancer sites. Special emphasis is given to gender differences in obesity-related cancers and on the effect of bariatric surgery on cancer risk.

RECENT FINDINGS

Accumulating evidence has highlighted the detrimental role of overweight/obesity in cancer, with almost 55% of cancers diagnosed in women and 24% diagnosed in men considered overweight- and obesity-related cancers. Sufficient data have shown that higher BMI is associated with risk of gynecologic malignancies (mainly breast and endometrial cancers) as well as cancers in sites such as the esophagus (adenocarcinoma), gastric cardia, colon, rectum, liver, gallbladder, pancreas, kidney, thyroid gland, and multiple myeloma. The main mechanisms underlying this relationship include the insulin/IGF1 system, the effect of sex hormones, and adipocytokines. Marked differences may be seen in specific cancer sites when comparing men to women. There is a higher overall incidence of obesity-related cancers among females (endometrial, ovarian, and postmenopausal female breast cancers), whereas cancers that concern both sexes show a higher incidence in males, particularly esophageal adenocarcinoma (male to female ratio: 9: 1 in the USA). Additionally, bariatric surgery has provided evidence of lowering overall cancer risk in patients with morbid obesity. Interestingly, bariatric surgery may lower overall cancer risk in women within the first 5 years after surgery due to the reduced risk of breast and endometrial cancer, and non-Hodgkin lymphoma. Obesity constitutes the base for marked metabolic, hormonal, and inflammatory alterations, including increased cancer risk in both men and women. Implementation of early obesity prevention strategies could ameliorate the continuously increasing incidence of cancer attributed to obesity.

Pancreatic Tumorigenesis: Oncogenic KRAS and the Vulnerability of the Pancreas to Obesity

Simple Summary

Pancreatic cancer is a devastating disease with a poor survival rate, and oncogenic mutant KRAS is a major driver of its initiation and progression; however, effective strategies/drugs targeting major forms of mutant KRAS have not been forthcoming. Of note, obesity is known to worsen mutant KRAS-mediated pathologies, leading to PDAC with high penetrance; however, the mechanistic link between obesity and pancreatic cancer remains elusive. The recent discovery of FGF21 as an anti-obesity and anti-inflammation factor and as a downstream target of KRAS has shed new light on the problem.

Abstract

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal malignancies and KRAS (Kirsten rat sarcoma 2 viral oncogene homolog) mutations have been considered a critical driver of PDAC initiation and progression. However, the effects of mutant KRAS alone do not recapitulate the full spectrum of pancreatic pathologies associated with PDAC development in adults. Historically, mutant KRAS was regarded as constitutively active; however, recent studies have shown that endogenous levels of mutant KRAS are not constitutively fully active and its activity is still subject to up-regulation by upstream stimuli. Obesity is a metabolic disease that induces a chronic, low-grade inflammation called meta-inflammation and has long been recognized clinically as a major modifiable risk factor for pancreatic cancer. It has been shown in different animal models that obesogenic high-fat diet (HFD) and pancreatic inflammation promote the rapid development of mutant KRAS-mediated PDAC with high penetrance. However, it is not clear why the pancreas with endogenous levels of mutant KRAS is vulnerable to chronic HFD and inflammatory challenges. Recently, the discovery of fibroblast growth factor 21 (FGF21) as a novel anti-obesity and anti-inflammatory factor and as a downstream target of mutant KRAS has shed new light on this problem. This review is intended to provide an update on our knowledge of the vulnerability of the pancreas to KRAS-mediated invasive PDAC in the context of challenges engendered by obesity and associated inflammation.

Induction Chemotherapy for Primarily Unresectable Locally Advanced Pancreatic Adenocarcinoma-Who Will Benefit from a Secondary Resection?

Background and Objectives: An increasing number of patients (pts) with locally advanced pancreatic cancer (LAPC) are treated with an intensive neoadjuvant therapy to obtain a secondary curative resection. Only a certain number of patients benefit from this intention. The aim of this investigation was to identify prognostic factors which may predict a benefit for secondary resection. Materials and Methods: Survival time and clinicopathological data of pts with pancreatic cancer were prospective and consecutively collected in our Comprehensive Cancer Center Database. For this investigation, we screened for pts with primarily unresectable pancreatic cancer who underwent a secondary resection after receiving induction therapy in the time between March 2017 and May 2019. Results: 40 pts had a sufficient database to carry out a reliable analysis. The carbohydrate-antigen 19-9 (CA 19-9) level of the pts treated with induction therapy decreased by 44.7% from 4358.3 U/mL to 138.5 U/mL (p = 0.001). The local cancer extension was significantly reduced (p < 0.001), and the Eastern Cooperative Oncology Group (ECOG) performance status was lowered (p = 0.03). The median overall survival (mOS) was 20 months (95% CI: 17.2–22.9). Pts who showed a normal CA 19-9 level (<37 U/mL) at diagnosis and after neoadjuvant therapy or had a Body Mass Index (BMI) below 25 kg/m² after chemotherapy had a significant prolonged overall survival (29 vs. 19 months, p = 0.02; 26 vs. 18 months, p = 0.04; 15 vs. 24 months, p = 0.01). Pts who still presented elevated CA 19-9 levels >400 U/mL after induction therapy did not profit from a secondary resection (24 vs. 7 months, p < 0.001). Nodal negativity as well as the performance of an adjuvant therapy lead to better mOS (25 vs. 15 months, p = 0.003; 10 vs. 25 months, p < 0.001). Conclusion: The pts in our investigation had different benefits from the multimodal treatment. We identified the CA 19-9 level at time of diagnosis and after neoadjuvant therapy as well as the preoperative BMI as predictive factors for overall survival. Furthermore, diagnostics of presurgical nodal status should gain more importance as nodal negativity is associated with better outcome.

The obesity paradox for mid- and long-term mortality in older cancer patients: a prospective multicenter cohort study

BACKGROUND

Overweight and obesity are associated with adverse health outcomes. However, substantial literature suggests that they are associated with longer survival among older people. This "obesity paradox" remains controversial. In the context of cancer, the association between overweight/obesity and mortality is complicated by concomitant weight loss (WL). Sex differences in the relation between BMI (in kg/m2) and survival have also been observed.

OBJECTIVES

We studied whether a high BMI was associated with better survival, and whether the association differed by sex, in older patients with cancer.

METHODS

We studied patients aged ≥70 y from the ELCAPA (Elderly Cancer Patients) prospective open cohort (2007-2016; 10 geriatric oncology clinics, Greater Paris urban area). The endpoints were 12- and 60-mo mortality. We created a variable combining BMI at cancer diagnosis and WL in the previous 6 mo, and considered 4 BMI categories-underweight (BMI < 22.5), normal weight (BMI = 22.5-24.9), overweight (BMI = 25-29.9), and obesity (BMI ≥ 30)-and 3 WL categories-<5% (minimal), 5% to <10% (moderate), and ≥10% (severe). Univariate and multivariate Cox proportional hazards analyses were conducted in men and women.

RESULTS

A total of 2071 patients were included (mean age: 81 y; women: 48%; underweight: 30%; normal weight: 23%; overweight: 33%; obesity: 14%; predominant cancer sites: colorectal (18%) and breast (16%); patients with metastases: 49%). By multivariate analysis, obese women with WL < 5% had a lower 60-mo mortality risk than normal-weight women with WL < 5% (adjusted HR: 0.56; 95% CI: 0.37, 0.86; P = 0.012). Overweight/obese women with WL ≥ 5% did not have a lower mortality risk than normal-weight women with WL < 5%. Overweight and obese men did not have a lower mortality risk, irrespective of WL.

CONCLUSIONS

By taking account of prediagnosis WL, only older obese women with cancer with minimal WL had a lower mortality risk than their counterparts with normal weight.This trial was registered at clinicaltrials.gov as NCT02884375.

The Role of Dysfunctional Adipose Tissue in Pancreatic Cancer: A Molecular Perspective

Pancreatic cancer (PC) is a lethal malignancy with rising incidence and limited therapeutic options. Obesity is a well-established risk factor for PC development. Moreover, it negatively affects outcome in PC patients. Excessive fat accumulation in obese, over- and normal-weight individuals induces metabolic and inflammatory changes of adipose tissue microenvironment leading to a dysfunctional adipose “organ”. This may drive the association between abnormal fat accumulation and pancreatic cancer. In this review, we describe several molecular mechanisms that underpin this association at both local and systemic levels. We focus on the role of adipose tissue-derived circulating factors including adipokines, hormones and pro-inflammatory cytokines, as well as on the impact of the local adipose tissue in promoting PC. A discussion on potential therapeutic interventions, interfering with pro-tumorigenic effects of dysfunctional adipose tissue in PC, is included. Considering the raise of global obesity, research efforts to uncover the molecular basis of the relationship between pancreatic cancer and adipose tissue dysfunction may provide novel insights for the prevention of this deadly disease. In addition, these efforts may uncover novel targets for personalized interventional strategies aimed at improving the currently unsatisfactory PC therapeutic options.

Increased Adiposity Enhances the Accumulation of MDSCs in the Tumor Microenvironment and Adipose Tissue of Pancreatic Tumor-Bearing Mice and in Immune Organs of Tumor-Free Hosts

Obesity is associated with increased risk and reduced survival for many types of cancer. Increasing adiposity may affect the balance between immunosuppressive and antitumor mechanisms critical for dictating cancer progression or remission. The goal of the current study was to determine if increased adiposity altered tumor growth, survival, and myeloid-derived suppressor cell (MDSC) accumulation in a subcutaneous murine model of pancreatic cancer. C57BL/6 mice were placed on a 30% kcal calorie-restricted diet, 10% kcal from fat diet fed ad libitum, or 60% kcal from fat diet fed ad libitum for 16 weeks to generate lean, overweight, and obese mice, respectively; followed by subcutaneous injection with 1 × 10⁶ Panc.02 cells. We observed a significant linear relationship between increased adiposity and increased tumor growth and mortality; increased accumulation of Gr-1⁺CD11b⁺ MDSCs; and reduced CD8 T cell:MDSC ratio in multiple tissues, including tumor. Increased adiposity also increased the accumulation of MDSCs in the spleen and lymph node of tumor-free mice. These data suggest adiposity induces MDSC accumulation, which may contribute to an immunosuppressive environment promoting tumor growth. Overall, our findings provide a rationale to prevent or reverse increased body weight as a strategy to reduce the accumulation of immunosuppressive cell types.

Obesity is Independently Associated With Increased Risk of Hepatocellular Cancer-related Mortality: A Systematic Review and Meta-Analysis

OBJECTIVE

Excess body weight is associated with increased risk of developing hepatocellular cancer (HCC), but its effect on HCC-related mortality remains unclear. We performed a systematic review and meta-analysis to assess the association between premorbid obesity and HCC-related mortality.

MATERIALS AND METHODS

Through a systematic literature search-up to March 2016, we identified 9 observational studies (1,599,453 individuals, 5705 HCC-related deaths) reporting the association between premorbid body mass index (BMI), and HCC-related mortality. We estimated summary adjusted hazard ratio (aHR) with 95% confidence intervals (CIs), comparing obese (BMI>30 kg/m(2)) and overweight (BMI, 25 to 29.9 kg/m(2)) individuals with normal BMI individuals using random-effects model.

RESULTS

On meta-analysis, compared with individuals with normal BMI, obese (aHR, 1.95; 95% CI, 1.46-2.46), but not overweight individuals (aHR, 1.08; 95% CI, 0.97-1.21), had higher HCC-related mortality, with moderate heterogeneity. On subgroup analysis, magnitude of increased mortality was higher in obese men (aHR, 2.50; 95% CI, 2.02-3.09; 3 studies) as compared with obese women (aHR, 1.45; 95% CI, 1.08-1.97; 2 studies). The impact of premorbid obesity on HCC-related mortality was observed only in western populations (aHR, 2.10; 95% CI, 1.77-2.48; 4 studies), but not Asian populations (aHR, 1.10; 95% CI, 0.63-1.92; 1 study). There was limited assessment of competing risk because of advanced liver disease.

CONCLUSIONS

On the basis of this meta-analysis, premorbid obesity may be independently associated with a 2-fold risk of HCC-related mortality. This association was more pronounced in men and western populations. Strategies targeting obesity-associated metabolic abnormalities may provide novel pathways for HCC therapy.

[Obesity and Cancer]

In the past decades, obesity and overweight prevalence has been rising worldwide, in both men and women. In France, the prevalence of overweight in adults was 49% in 2015 (54% among men and 44% among women), including 17% of obese adults. According to the last evaluation performed by IARC in 2017, overweight and obesity are established risk factors for 13 cancer sites with risk estimates per 5kg/m2 varying largely depending on the cancer site. In 2015 in France, 5.4% of cancer cases could be attributed to excess weight, corresponding to 18,600 cases, including 3400 colon cancers, 2600 kidney cancers, 4500 breast cancers and 2500 endometrial cancers. Obesity is also related to worse prognosis for some cancers, in particular breast and colon cancers. Obesity in children and adolescents, also rising in many countries, has also been associated to an increase in adult cancer risk. A major cause of obesity is a disequilibrium in energy balance favoured by a diet rich in processed food, red meat, trans and saturated fatty acids, sweetened foods and beverages and poor in fruits and vegetables, legumes and whole grains. Main national and international recommendations to reduce the prevalence of obesity are to have a balanced diet and regular physical activity.

The UCA1/KRAS axis promotes human pancreatic ductal adenocarcinoma stem cell properties and tumor growth

Emerging evidence indicates that the long noncoding RNA UCA1 is upregulated in multiple cancers, including pancreatic ductal adenocarcinoma (PDAC), and plays a critical role in various complex biological processes. However, the functional roles of UCA1 in PDAC remain to be clarified. In the current study, we showed that UCA1 significantly promoted cell proliferation and tumor growth both in vitro and in vivo, and enhanced stemness maintenance of PDAC cell lines. Moreover, we found that UCA1 overexpression increased the activity and expression of oncogenic KRAS. Mechanistically, upregulated UCA1 increased phospho-KRAS protein levels by interacting with hnRNPA2B1, and KRAS facilitated high cytoplasmic accumulation of hnRNPA2B1. Additionally, we identified that UCA1 functioned as a competing endogenous RNA (ceRNA) to increase the expression of KRAS via sponging miR-590-3p, and in turn, KRAS promoted UCA1 expression. Collectively, these findings suggest that the UCA1-KRAS axis plays a crucial role in PDAC progression and that UCA1 may serve as a target for new PDAC therapies.

Global patterns in excess body weight and the associated cancer burden

The prevalence of excess body weight and the associated cancer burden have been rising over the past several decades globally. Between 1975 and 2016, the prevalence of excess body weight in adults-defined as a body mass index (BMI) ≥ 25 kg/m² -increased from nearly 21% in men and 24% in women to approximately 40% in both sexes. Notably, the prevalence of obesity (BMI ≥ 30 kg/m² ) quadrupled in men, from 3% to 12%, and more than doubled in women, from 7% to 16%. This change, combined with population growth, resulted in a more than 6-fold increase in the number of obese adults, from 100 to 671 million. The largest absolute increase in obesity occurred among men and boys in high-income Western countries and among women and girls in Central Asia, the Middle East, and North Africa. The simultaneous rise in excess body weight in almost all countries is thought to be driven largely by changes in the global food system, which promotes energy-dense, nutrient-poor foods, alongside reduced opportunities for physical activity. In 2012, excess body weight accounted for approximately 3.9% of all cancers (544,300 cases) with proportion varying from less than 1% in low-income countries to 7% or 8% in some high-income Western countries and in Middle Eastern and Northern African countries. The attributable burden by sex was higher for women (368,500 cases) than for men (175,800 cases). Given the pandemic proportion of excess body weight in high-income countries and the increasing prevalence in low- and middle-income countries, the global cancer burden attributable to this condition is likely to increase in the future. There is emerging consensus on opportunities for obesity control through the multisectoral coordinated implementation of core policy actions to promote an environment conducive to a healthy diet and active living. The rapid increase in both the prevalence of excess body weight and the associated cancer burden highlights the need for a rejuvenated focus on identifying, implementing, and evaluating interventions to prevent and control excess body weight.

Long Non-Coding RNAs in Obesity-Induced Cancer

Many mechanisms of obesity-induced cancers have been proposed. However, it remains unclear whether or not long non-coding RNAs (lncRNAs) play any role in obesity-induced cancers. In this article, we briefly discuss the generally accepted hypotheses explaining the mechanisms of obesity-induced cancers, summarize the latest evidence for the expression of a number of well-known cancer-associated lncRNAs in obese subjects, and propose the potential contribution of lncRNAs to obesity-induced cancers. We hope this review can serve as an inspiration to scientists to further explore the regulatory roles of lncRNAs in the development of obesity-induced cancers. Those findings will be fundamental in the development of effective therapeutics or interventions to combat this life-threatening adverse effect of obesity.

The mitochondrial one-carbon metabolic pathway is associated with patient survival in pancreatic cancer

The expression levels of one-carbon metabolic enzymes were investigated and observed to be correlated with clinicopathological parameters in patients with pancreatic cancer. Mitochondrial one-carbon metabolism comprises a network of biological reactions that integrate nutrient status with nucleotide synthesis, amino acid metabolism, antioxidant reduced nicotinamide adenine dinucleotide phosphate production and epigenetic methylation processes. Previous studies have reported that the hyper-activation of mitochondrial one-carbon metabolism serves a significant role in malignant cancer phenotypes. A total of 103 patients underwent surgical resection of pancreatic ductal adenocarcinomas (PDAC) at Osaka University Hospital between April 2007 and December 2013 and were enrolled in this study. Subsequently, the expression of the one-carbon metabolic enzymes methylenetetrahydrofolate dehydrogenase 2 (MTHFD2), aldehyde dehydrogenase 1 family member L2 (ALDH1L2), and serine hydroxymethyltransferase (SHMT2) was examined using immunohistochemical analysis. The immunohistochemical analyses demonstrated that patients with high expression levels of MTHFD2, ALDH1L2 or SHMT2 had significantly poor overall survival (OS) and disease-free survival (DFS) rates, as compared with patients with low expression levels. Furthermore, multivariate Cox proportional hazards analysis indicated that MTHFD2 and ALDH1L2 were independent prognostic factors for OS and DFS, whereas SHMT2 was not predictive of DFS. However, high and low expression levels of all three folate metabolic enzymes were significantly associated with improved OS and DFS, compared with the high expression of one or two folate metabolic enzymes. The expression levels of mitochondrial one-carbon metabolic enzymes are independent prognostic factors and potential therapeutic targets for future pancreatic cancer treatments.

c-Met affects gemcitabine resistance during carcinogenesis in a mouse model of pancreatic cancer

Pancreatic adenocarcinoma is thought to develop from histologically identifiable intraductal lesions known as pancreatic intraepithelial neoplasias (PanINs), which exhibit similar morphological and genetic features to pancreatic ductal adenocarcinoma (PDAC). Therefore, a better understanding of the biological features underlying the progression of PanIN is essential to development more effective therapeutic interventions for PDAC. In recent years, numerous studies have reported that MET proto-oncogene receptor tyrosine kinase (c-MET) is a potential marker of pancreatic cancer stem cells (CSCs). CSCs have been revealed to initiate and propagate tumors in vitro and in vivo, and are associated with a chemoresistant phenotype. However, in vivo models using a xenograft approach are limited. In the present study, the morphological phenotype, molecular alteration and biological behavior of neoplasia in Pdx-1Cre/+, KrasLSL-G12D/+ and Metflox/flox and wild-type mice was analyzed. The results demonstrated that while oncogenic KrasLSL-G12D/+ increased PanIN initiation and significantly decreased survival rate compared with wild-type mice, no additive effect of c-Met receptor signaling on PanIN progression or prognosis was observed. Following gemcitabine administration, c-Met inhibition in Kras LSL-G12D/+ mice significantly decreased the total surface area of PanIN lesions and the number of anti-proliferation marker protein Ki-67 positive cells occupying PanIN lesions compared with Met+/+ mice. In conclusion, complete inhibition of the c-Met signaling pathway with chemotherapy may be useful for the treatment of pancreatic cancer.

Lipocalin-2 Promotes Pancreatic Ductal Adenocarcinoma by Regulating Inflammation in the Tumor Microenvironment

Lipocalin-2 (LCN2) promotes malignant development in many cancer types. LCN2 is upregulated in patients with pancreatic ductal adenocarcinoma (PDAC) and in obese individuals, but whether it contributes to PDAC development is unclear. In this study, we investigated the effects of Lcn2 depletion on diet-induced obesity, inflammation, and PDAC development. Mice with acinar cell-specific expression of KrasG12D were crossed with Lcn2-depleted animals and fed isocaloric diets with varying amounts of fat content. Pancreas were collected and analyzed for inflammation, pancreatic intraepithelial neoplasia (PanIN), and PDAC. We also used a syngeneic orthotopic PDAC mouse model to study tumor growth in the presence or absence of Lcn2 expression. In addition, to understand the mechanistic role of how LCN2 could be mediating PDAC, we studied LCN2 and its specific receptor solute carrier family 22 member 17 (SLC22A17) in human pancreatic cancer stellate cells (PSC), key mediators of the PDAC stroma. Depletion of Lcn2 diminished extracellular matrix deposition, immune cell infiltration, PanIN formation, and tumor growth. Notably, it also increased survival in both obesity-driven and syngeneic orthotopic PDAC mouse models. LCN2 modulated the secretion of proinflammatory cytokines in PSC of the PDAC tumor microenvironment, whereas downregulation of LCN2-specific receptor SLC22A17 blocked these effects. Our results reveal how LCN2 acts in the tumor microenvironment links obesity, inflammation, and PDAC development. Cancer Res; 77(10); 2647-60. ©2017 AACR.

A review of the impact of obesity on common gastrointestinal malignancies

Obesity is a global pandemic and is a well-recognized risk factor for various gastrointestinal diseases. The prevalence of obesity is increasing across all age groups. There is an emergent need for focused guidelines aimed at reducing the incidence, prevalence, and associated risks of obesity. The impact of obesity on gastrointestinal cancers being multifactorial adversely influences the associated risk, disease course, prognosis, and overall survival. We have summarized the current literature highlighting the association between obesity and common gastrointestinal cancers, with specific focus on esophageal adenocarcinoma, colon cancer, hepatocellular cancer, cholangiocarcinoma, and pancreatic malignancies.

Surveillance for neoplasia in the pancreas

Despite its low incidence in the general population, pancreatic cancer is one of the leading causes of cancer-related mortality. Survival greatly depends on operability, but most patients present with unresectable disease. Therefore, there is great interest in the early detection of pancreatic cancer and its precursor lesions by surveillance. Worldwide, several programs have been initiated for individuals at high risk for pancreatic cancer. Their first results suggest that surveillance in high-risk individuals is feasible, but their effectiveness in decreasing mortality remains to be proven. This review will discuss which individuals are eligible for surveillance, which lesions are aimed to be detected, and which surveillance modalities are being used in current clinical practice. Furthermore, it addresses the management of abnormalities found during surveillance and topics for future research.

The Impact of Obesity on Gallstone Disease, Acute Pancreatitis, and Pancreatic Cancer

Obesity is a well-recognized risk factor for gallstone formation and increases the risk for gallstone-related complications. Pancreatic diseases are impacted adversely by obesity. Although weight loss surgery increases the risk of gallstone disease, evidence suggests that bariatric surgery mitigates the obesity-associated adverse prognostication in acute pancreatitis. Obesity is also a significant risk factor for pancreatic cancer. Obesity is a global epidemic and is increasing worldwide and among all age groups. There is an urgent need for focused health policies aimed at reducing the incidence and prevalence of obesity. This article summarizes the current literature highlighting the association between obesity and the pathophysiology and outcome of gallstone disease, pancreatitis, and pancreatic cancer.

Obesity and cancer: inflammation bridges the two

Obesity is a growing public health problem and affects 35% US adults. Obesity increases the risk of many cancer types and is associated with poor outcomes. Clinical management of cancer patients has been essentially the same between normal weight and obese individuals. Understanding causal mechanisms by which obesity drives cancer initiation and progression is essential for the development of novel precision therapy for obese cancer patients. One caveat is that various mechanisms have been proposed for different cancer types for their progression under obesity. Since obesity is known to have global impact on inflammation, here we will summarize recent literature and discuss the potential of inflammation being the common causal mechanism to promote cancer promotion across cancer types.

Characteristics of Venous Thromboembolism in Pancreatic Adenocarcinoma in East Asian Ethnics: A Large Population-Based Observational Study

Pancreatic cancer (PC) is known to be frequently associated with venous thromboembolism (VTE). Although treatment and prophylaxis strategies for VTE in PC patients were updated recently, these were mainly based on data from Western populations and were not verified in East Asian ethnic populations.We investigated the clinical characteristics of VTE in East Asian PC patients. We reviewed electronic medical records (EMR) of 1334 patients diagnosed with pancreatic adenocarcinoma from 2005 to 2010 at single tertiary hospital in Korea. All the patients with newly diagnosed VTE were classified by anatomical site and manifestation of symptoms. The primary outcomes of interest were 2-year cumulative incidence of VTE events. Cox proportional hazards models were used to analyze associations between risk factors and clinical outcomes.A total of 1115 patients were eligible for enrollment. The 2-year cumulative VTE incidence was 9.2%. Major risk factors associated with VTE event were advanced cancer stage, major surgery, and poor performance status. Risk factors associated with mortality after PC diagnosis included advanced cancer stage, poor performance score, leukocytosis, and lower albumin level. The overall VTE did not affected mortality. However in subgroup analysis, symptomatic VTE and deep vein thrombosis/pulmonary thromboembolism (DVT/PTE) showed worse prognosis than incidental or intra-abdominal VTE.The overall incidence of VTE events in Korean PC patients was lower than previous studies. Advanced cancer stage was the most important factor for VTE event and mortality. Unlike Western population group, VTE event did not affect overall prognosis after PC diagnosis. However, symptomatic VTE and DVT/PTE showed higher mortality after VTE event.

PlGF/VEGFR-1 Signaling Promotes Macrophage Polarization and Accelerated Tumor Progression in Obesity

PURPOSE

Obesity promotes pancreatic and breast cancer progression via mechanisms that are poorly understood. Although obesity is associated with increased systemic levels of placental growth factor (PlGF), the role of PlGF in obesity-induced tumor progression is not known. PlGF and its receptor VEGFR-1 have been shown to modulate tumor angiogenesis and promote tumor-associated macrophage (TAM) recruitment and activity. Here, we hypothesized that increased activity of PlGF/VEGFR-1 signaling mediates obesity-induced tumor progression by augmenting tumor angiogenesis and TAM recruitment/activity.

EXPERIMENTAL DESIGN

We established diet-induced obese mouse models of wild-type C57BL/6, VEGFR-1 tyrosine kinase (TK)-null, or PlGF-null mice, and evaluated the role of PlGF/VEGFR-1 signaling in pancreatic and breast cancer mouse models and in human samples.

RESULTS

We found that obesity increased TAM infiltration, tumor growth, and metastasis in pancreatic cancers, without affecting vessel density. Ablation of VEGFR-1 signaling prevented obesity-induced tumor progression and shifted the tumor immune environment toward an antitumor phenotype. Similar findings were observed in a breast cancer model. Obesity was associated with increased systemic PlGF, but not VEGF-A or VEGF-B, in pancreatic and breast cancer patients and in various mouse models of these cancers. Ablation of PlGF phenocopied the effects of VEGFR-1-TK deletion on tumors in obese mice. PlGF/VEGFR-1-TK deletion prevented weight gain in mice fed a high-fat diet, but exacerbated hyperinsulinemia. Addition of metformin not only normalized insulin levels but also enhanced antitumor immunity.

CONCLUSIONS

Targeting PlGF/VEGFR-1 signaling reprograms the tumor immune microenvironment and inhibits obesity-induced acceleration of tumor progression. Clin Cancer Res; 22(12); 2993-3004. ©2016 AACR.