Adult weight change and risk of colorectal cancer in the European Prospective Investigation into Cancer and Nutrition

Challenges and Opportunities for Precision Surgery for Colorectal Liver Metastases

The incidence of colorectal cancer and colorectal liver metastases (CRLM) is increasing globally due to an interaction of environmental and genetic factors. A minority of patients with CRLM have surgically resectable disease, but for those who have resection as part of multimodal therapy for their disease, long-term survival has been shown. Precision surgery-the idea of careful patient selection and targeting of surgical intervention, such that treatments shown to be proven to benefit on a population level are the optimal treatment for each individual patient-is the new paradigm of care. Key to this is the understanding of tumour molecular biology and clinically relevant mutations, such as KRAS, BRAF, and microsatellite instability (MSI), which can predict poorer overall outcomes and a poorer response to systemic therapy. The emergence of immunotherapy and hepatic artery infusion (HAI) pumps show potential to convert previously unresectable disease to resectable disease, in addition to established systemic and locoregional therapies, but the surgeon must be wary of poor-quality livers and the spectre of post-hepatectomy liver failure (PHLF). Volume modulation, a cornerstone of hepatic surgery for a generation, has been given a shot in the arm with the advent of liver venous depletion (LVD) ensuring significantly more hypertrophy of the future liver remnant (FLR). The optimal timing of liver resection for those patients with synchronous disease is yet to be truly established, but evidence would suggest that those patients requiring complex colorectal surgery and major liver resection are best served with a staged approach. In the operating room, parenchyma-preserving minimally invasive surgery (MIS) can dramatically reduce the surgical insult to the patient and lead to better perioperative outcomes, with quicker return to function.

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

BACKGROUND AND AIM

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

OBJECTIVE

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

DESIGN

Prospective cohort study.

SETTING

Forty clinical centres in the USA.

PARTICIPANTS

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

RESULTS

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

CONCLUSION

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

The risk of colorectal cancer according to obesity status at four-year intervals: a nationwide population-based cohort study

Obesity is a risk factor for colorectal cancer. However, the effect of body weight change on colorectal cancer is uncertain. This study aimed to investigate the relationship between difference in body mass index and the risk of colorectal cancer. In this nationwide population-based cohort study, participants of the national cancer screening program in 2005 and 2009 were enrolled. Difference of body mass index was calculated from screening data from 2005 and 2009. Participants were divided into four groups according to direction of obesity status: non-obese/non-obese, non-obese/obese, obese/non-obese, and obese/obese. The effect of differences in body mass index on colorectal cancer was analyzed. Among 3,858,228 participants, 47,894 (1.24%) participants were newly diagnosed with colorectal cancer during the 9.2 years of follow-up. The incidence of colorectal cancer was higher in the obese/obese group than the non-obese/non-obese group (hazard ratio = 1.08 [1.06-1.11], P trend < 0.001). The men in the obese/obese group had a higher risk of colon cancer than women (hazard ratio = 1.13 [1.10-1.17] in men, and hazard ratio = 1.04 [1.01-1.18] in women, P = 0.001). Persistent obesity was associated with a higher risk of incidence of colorectal cancer.

Association of Overweight, Obesity, and Recent Weight Loss With Colorectal Cancer Risk

Importance

Overweight and obesity, conditions with rising prevalence in many countries, are associated with increased colorectal cancer (CRC) risk. However, many patients with CRC lose weight before diagnosis, which may lead the association to be underestimated.

Objective

To evaluate the association of body mass index (BMI) and weight change with CRC risk when considering BMI at different time frames, with the intention to account for prediagnostic weight loss.

Design, Setting, and Participants

This population-based case-control study was conducted in southwestern Germany between 2003 and 2021. Cases with a first diagnosis of CRC and controls (frequency matched by age, sex, and county) with comprehensive risk factor information and self-reported weight at different time points were included. Data were analyzed between October 2022 and March 2023.

Exposure

BMI and weight change at different time frames before the time of diagnosis (cases) or recruitment (controls).

Main Outcomes and Measures

Association of BMI and weight change at various points in time before and up to diagnosis with CRC, assessed by multivariable logistic regression with comprehensive confounder adjustment.

Results

A total of 11 887 participants (6434 CRC cases, 5453 controls; median [IQR] age, 69 [61-77] years; 7173 male [60.3%]) were included. At the time of diagnosis, 3998 cases (62.1%) and 3601 controls (66.0%) were overweight or obese, suggesting an inverse association between excess weight and CRC risk. Conversely, we found significant positive associations of overweight (adjusted odds ratio [aOR], 1.27; 95% CI, 1.03-1.56), obesity (aOR, 2.09; 95% CI, 1.61-2.70), and a 5-unit increase in BMI (aOR, 1.35; 95% CI, 1.21-1.50) with CRC risk when using BMI measured 8 to 10 years before diagnosis. High BMI as a risk factor for CRC was increased as earlier periods before diagnosis were examined, with the association being particularly pronounced using BMI at least 8 years before diagnosis. An opposite trend was found for the association of weight loss (at or exceeding 2 kg) with CRC, with the greatest effect sizes occurring for weight loss within 2 years before diagnosis (aOR, 7.52; 95% CI, 5.61-10.09), and gradually decreased for earlier intervals.

Conclusions and Relevance

In this population-based case-control study, accounting for substantial prediagnostic weight loss further highlighted the association of overweight and obesity with CRC risk.

Changes in Lifestyle and Risk of Colorectal Cancer in the European Prospective Investigation Into Cancer and Nutrition

INTRODUCTION

We investigated the impact of changes in lifestyle habits on colorectal cancer (CRC) risk in a multicountry European cohort.

METHODS

We used baseline and follow-up questionnaire data from the European Prospective Investigation into Cancer cohort to assess changes in lifestyle habits and their associations with CRC development. We calculated a healthy lifestyle index (HLI) score based on smoking status, alcohol consumption, body mass index, and physical activity collected at the 2 time points. HLI ranged from 0 (most unfavorable) to 16 (most favorable). We estimated the association between HLI changes and CRC risk using Cox regression models and reported hazard ratios (HR) with 95% confidence intervals (CI).

RESULTS

Among 295,865 participants, 2,799 CRC cases were observed over a median of 7.8 years. The median time between questionnaires was 5.7 years. Each unit increase in HLI from the baseline to the follow-up assessment was associated with a statistically significant 3% lower CRC risk. Among participants in the top tertile at baseline (HLI > 11), those in the bottom tertile at follow-up (HLI ≤ 9) had a higher CRC risk (HR 1.34; 95% CI 1.02-1.75) than those remaining in the top tertile. Among individuals in the bottom tertile at baseline, those in the top tertile at follow-up had a lower risk (HR 0.77; 95% CI 0.59-1.00) than those remaining in the bottom tertile.

DISCUSSION

Improving adherence to a healthy lifestyle was inversely associated with CRC risk, while worsening adherence was positively associated with CRC risk. These results justify and support recommendations for healthy lifestyle changes and healthy lifestyle maintenance for CRC prevention.

Retrospective study of clinic-epidemiological correlation between body mass index (BMI) and colorectal cancer (CRC) with survival impact

BACKGROUND

Body mass index (BMI) is positively associated with the risk of colorectal cancer (CRC). For that reason, investigators have hypothesized that being overweight or obese leads to worse CRC prognosis and survival outcome.

METHODOLOGY

The impact of BMI in patients with colorectal cancer on (disease free survival) DFS and three years overall survival (OS) rates in correlation with clinic-pathological data of those patients was studied on 128 patients enrolled in this study. They were diagnosed with stage II and III colorectal cancer that presented at clinical oncology department Ain Shams University hospitals from January 2016 till December 2017 with 3 years duration follow up. All of them had measured their BMI at time of presentation.

RESULTS

Estimated 3- years OS for each BMI category revealed that normal weight patients had 97.1% survival rate and overweight patients had 77.8% survival rate. Much lower survival rates for both underweight and obese patients had been estimated being (33.3%, 37.3%) respectively. This correlation to BMI categories shows a statistically significant value between normal weight patients and overweight patients in relation to underweight and obese patients (p- value < 0.0001).

CONCLUSION

BMI has an impact on colorectal cancer patients with clinicopathological relations and survival rate.

Chinese consensus on prevention of colorectal neoplasia (2021, Shanghai)

Most patients with colorectal cancer (CRC) were diagnosed in advanced stage and the prognosis is poor. Therefore, early detection and prevention of CRC are very important. As with other cancers, there is also the tertiary prevention for CRC. The primary prevention is etiological prevention, which is mainly the treatment of adenoma or inflammation for preventing the development into cancer. The secondary prevention is the early diagnosis and early treatment for avoiding progressing to advanced cancer. The tertiary prevention belongs to the broad category of prevention, mainly for advanced CRC, through surgical treatment and postoperative adjuvant chemotherapy, radiotherapy, targeted therapy, immunotherapy for preventing tumor recurrence or metastasis. This consensus is based on the recent domestic and international consensus guidelines and the latest progress of international researches in the past five years. This consensus opinion seminar was hosted by the Chinese Society of Gastroenterology and Cancer Collaboration Group of Chinese Society of Gastroenterology, and was organized by the Division of Gastroenterology and Hepatology & Shanghai Institute of Digestive Disease, Renji Hospital, School of Medicine, Shanghai Jiao Tong University. The consensus opinion contains 60 statement clauses, the standard and basis of the evidence-based medicine grade and voting grade of the statement strictly complied with the relevant international regulations and practice.

Preoperative Neutrophil-BMI Ratio As a Promising New Marker for Predicting Tumor Outcomes in Colorectal Cancer

Background: Inflammation and nutritional status are highly associated with colorectal cancer (CRC) prognosis. This study aimed to evaluate the prognostic value of the preoperative neutrophil-BMI ratio (NBR) in patients with CRC. Methods: A retrospective analysis was performed on 2471 patients with CRC who underwent surgical resection between 2004 and 2019. Patients were divided into two groups based on the cutoff value for NBR. Cox regression and Kaplan–Meier curves were used to evaluate overall survival (OS). Results: High NBR was associated with female sex, low BMI, colon, right-sided CRC, poor differentiation, T3 to 4 stage, M1 to 2 stage, high carcinoembryonic antigen (CEA) level, III-IV stage, microsatellite instability (MSI), and no adjuvant chemotherapy (all P < .05). The high NBR group had a shorter OS than the low NBR group. Female and right sided patients with CRC and with high NBR had a worse prognosis. Univariate Cox regression suggested that NBR was significantly associated with poor prognosis. Multivariate analysis confirmed that age (P = .019,HR:1.012), differentiation (P = .001,HR:1.306), TNM stage (P < .001,HR:2.432), CEA (P = .014,HR:1.001), and NBR (P < .001, HR: 3.309) were independent poor prognostic factors for OS. Subgroup univariate analysis indicated that female patients with high NBR had a worse prognosis. A nomogram composed of TNM stage, CEA, and NBR was developed, and internal validation was based on female patients with CRC. The nomogram provided good discrimination for both the training and validation sets, with area under the curve values of 0.79 and 0.769, respectively. Conclusions: High preoperative levels of NBR are indicators of poor prognosis in patients with CRC.

Narrative review of the influence of diabetes mellitus and hyperglycemia on colorectal cancer risk and oncological outcomes

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Diabetes mellitus and hyperglycemia significantly affect the incidence and prognosis of colorectal cancer.

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Evidence of the effects of metformin remain controversial in cancer prognosis.

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Potential molecular mechanisms by which DM and hyperglycemia affects cancer risk.

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Potential roles of glucose modulation in CRC therapy.

Diabetes mellitus (DM) and hyperglycemia have been shown to have significant effects on the incidence, chemoresistance, and prognosis of colorectal cancer (CRC), as well as the outcomes of localized and metastatic CRC. Inflammation and endocrine effects may act as central mechanisms of DM and cancer and stimulate the insulin‐like growth factor 1–phosphoinositide 3-kinase–Akt–mammalian target of rapamycin (IGF-1–PI3K–AKT–mTOR) pathway. Dysregulation of the AMP-activated protein kinase (AMPK) pathway leads to metabolic imbalance and indicates cancer risk. The use of metformin for chemoprevention has been shown to reduce CRC and adenoma incidence through the upregulation of AMPK, which causes cell cycle arrest in the Gap 1–S (G1–S) phase and inhibits the mTOR pathway, even potentially reversing the epithelial–mesenchymal transition. However, evidence of the effects of metformin remain controversial in cancer prognosis. Several genes, such as transcription factor 7-like 2(TCF7L2), tumor protein P53 inducible nuclear protein 1(TP53INP1), gremlin 1 (GREM1), and potassium voltage-gated channel subfamily Q member 1(KCNQ1), are pleiotropically related to DM as well as cancer risk and prognosis. Epigenetic modification of members of the Let-7 family such as miR-497, miR-486, and miR-223 is strongly associated with impaired glucose tolerance and CRC risk. Herein we review the pathophysiological and epidemiological evidence as well as potential underlying molecular mechanisms by which DM and hyperglycemia affect CRC risk. We also suggest potential roles of glucose modulation in CRC therapy and propose an agenda for future research and clinical practice.

Systematic Review of Prevalence, Risk Factors, and Risk for Metachronous Advanced Neoplasia in Patients With Young-Onset Colorectal Adenoma

BACKGROUND & AIMS

The incidence and mortality of early-onset colorectal cancer (CRC) are increasing. Adenoma detection, removal, and subsequent endoscopic surveillance might modify risk of CRC diagnosed before age 50 years (early-onset CRC). We conducted a systematic review of young-onset adenoma (YOA) prevalence, associated risk factors, and rate of metachronous advanced neoplasia after YOA diagnosis.

METHODS

We performed a systematic search of multiple electronic databases through February 12, 2019 and identified studies of individuals 18 to 49 years old that reported prevalence of adenoma, risk factors for adenoma, and/or risk for metachronous advanced neoplasia. Summary estimates were derived using random effects meta-analysis, when feasible.

RESULTS

The pooled overall prevalence of YOA was 9.0% (95% CI, 7.1%-11.4%), based on 24 studies comprising 23,142 individuals. On subgroup analysis, the pooled prevalence of YOA from autopsy studies was 3.9% (95% CI, 1.9%-7.6%), whereas the prevalence from colonoscopy studies was 10.7% (95% CI, 8.5%-13.5). Only advancing age was identified as a consistent risk factor for YOA, based on 4 studies comprising 78,880 individuals. Pooled rate of metachronous advanced neoplasia after baseline YOA diagnosis was 6.0% (95% CI, 4.1%-8.6%), based on 3 studies comprising 1493 individuals undergoing follow-up colonoscopy, with only 1 CRC case reported. Overall, few studies reported metachronous advanced neoplasia and no studies evaluated whether routine surveillance colonoscopy decreases risk of CRC.

CONCLUSIONS

In a systematic review, we estimated the prevalence of YOA to be 9% and to increase with age. Risk for metachronous advanced neoplasia after YOA diagnosis is estimated to be 6%. More research is needed to understand the prevalence, risk factors, and risk of CRC associated with YOA.

Preventable fractions of cancer incidence attributable to 7-years weight gain in the Norwegian Women and Cancer (NOWAC) study

There is a lack of tangible measures for directed public health action to halt the increase in weight and cancer. We estimated the fraction and preventable cases of all and major body fatness-related cancers attributable to 7-years weight gain (≥ 2 kg). We assessed validated self-reported anthropometrics from 44,114 women aged 34-49 years at the enrolment in 1991-1992 and from a second questionnaire in 1998, with follow-up through December 31, 2015. Over 18 years, 3216 body fatness-related cancers and 2041 deaths were reported. Nearly 70% of women experienced weight gain and the average weight change was 4 kg. We observed a substantial proportional impact of weight gain on pancreatic cancer with a population attributable fraction (PAF) of 41.8% (95% CI 8.1-63.1) and a high absolute impact on postmenopausal breast cancer with 4403 preventable cases (95% CI 1064-7299) and a PAF of 16.8% (95% CI 4.1-27.8), and colorectal cancer with 3857 preventable cases (95% CI 1313-5990) and a PAF of 22.6% (95% CI 7.7-35.1). Avoiding weight gain over seven years in middle adulthood could have prevented a considerable proportion of the cancer burden and thousands of cancer cases in women in Norway.

The prognostic impact of RAS on overall survival following liver resection in early versus late-onset colorectal cancer patients

BACKGROUND

The impact of molecular aberrations on survival after resection of colorectal liver metastases (CLM) in patients with early-age-onset (EOCRC) versus late-age-onset colorectal cancer (LOCRC) is unknown.

METHODS

Patients who underwent liver resection for CLM with known RAS, BRAF and MSI status were retrospectively studied. The prognostic impact of RAS mutations by age was analysed with age as a categorical variable and a continuous variable.

RESULTS

The study included 573 patients, 192 with EOCRC and 381 with LOCRC. The younger the age of onset of CRC, the greater the negative impact on overall survival of RAS mutations in the LOCRC, EOCRC, and ≤40 years (hazard ratio (HR), 1.64 (95% confidence interval (CI), 1.23-2.20), 2.03 (95% CI, 1.30-3.17), and 2.97 (95% CI, 1.44-6.14), respectively. Age-specific mortality risk and linear regression analysis also demonstrated that RAS mutations had a greater impact on survival in EOCRC than in LOCRC (slope: -4.07, 95% CI -8.10 to 0.04, P = 0.047, R² = 0.08).

CONCLUSION

Among patients undergoing CLM resection, RAS mutations have a greater negative influence on survival in patients with EOCRC, more so in patients ≤40 years, than in patients with LOCRC and should be considered as a prognostic factor in multidisciplinary treatment planning.

Colon cancer combined with obesity indicates improved survival- research on relevant mechanism

Obesity contributes to the incidence of various tumors, including colon cancer. However, the impact of obesity on patients’ survival and related mechanisms remains unclear. Multi-omics data of 227 cases of colon cancer patients combined with clinical characteristics data were acquired from The Cancer Genome Atlas (TCGA) database. We confirmed obesity as an independent prognostic factor for improved overall survival of colon cancer patients. We demonstrated that hypoxia pathways were repressed in obese patients by regulating miR-210. Immune checkpoints PD-1 and LAG3 were also downregulated in obese patients, which indicated enhanced immune surveillance. The frequency of PIK3CA and KRAS mutations was decreased in obese patients. The sites and types of TP53 mutation were alternated in obesity patients. In conclusion, our research demonstrated the potential mechanisms of prolonged survival in colon cancer patients combined with obesity, which may provide potential value for improving the prognosis of colon cancer.

Weight change since age 20 and incident risk of obesity-related cancer in Japan: a pooled analysis of the Miyagi Cohort Study and the Ohsaki Cohort Study

It is unclear whether weight change during adulthood affects the risk of obesity-related cancers such as those of the esophagus, colorectum, pancreas, breast, endometrium, and kidney among Japanese, where obesity is less frequent and less severe. We examined the association between weight change during adulthood and the risk of obesity-related cancer among Japanese by conducting a pooled analysis of two prospective studies of residents in Miyagi Prefecture, Japan. A total of 78,743 persons (40,422 women and 38,321 men) aged 40-79 years participated in the Miyagi Cohort Study in 1990 and in the Ohsaki Cohort Study in 1994. Weight change since age 20 was divided into four categories (weight loss; stable weight; moderate weight gain; high weight gain). Cox proportional hazards regression analysis was used to estimate the multivariate hazard ratios (HRs) and 95% confidence intervals (CIs) for obesity-related cancer incidence. During 1,057,899 person-years of follow up, 4,467 cases of obesity-related cancer (women; 1,916 cases, men; 2,551cases) were identified. In women, compared to the stable weight, weight gain was associated with an increased risk of obesity-related cancer (moderate weight gain; HRs = 1.10, 95%CIs: 0.97-1.26, high weight gain; HRs = 1.29, 95%CIs: 1.14-1.47). The results indicate that weight gain since age 20 was associated with a significantly increased risk of obesity-related cancer among Japanese women. By contrast, in men, our study found that weight change is not associated with the incidence of obesity-related cancer.

Early-onset colorectal cancer in young individuals

Treatment of young adults with colorectal cancer (CRC) represents an unmet clinical need, especially as diagnosis in this population might lead to the greatest loss of years of life. Since 1994, CRC incidence in individuals younger than 50 years has been increasing by 2% per year. The surge in CRC incidence in young adults is particularly alarming as the overall CRC frequency has been decreasing. Early-onset CRC are characterized by a more advanced stage at diagnosis, poorer cell differentiation, higher prevalence of signet ring cell histology, and left colon-sided location of the primary tumor. Among EO-CRC, approximately 30% of patients are affected by tumors harboring mutations causing hereditary cancer predisposing syndromes, and 20% have familial CRC. Most notably, the remaining 50% of EO-CRC patients have neither hereditary syndromes nor familial CRC, thus representing a formidable challenge for research. In this review article we summarize epidemiology, clinical and molecular features, heredity and outcome of treatments of EO-CRC, and provide considerations for future perspectives.

Stem Cell Intrinsic Hexosamine Metabolism Regulates Intestinal Adaptation to Nutrient Content

The intestine is an organ with an exceptionally high rate of cell turnover, and perturbations in this process can lead to severe diseases such as cancer or intestinal atrophy. Nutrition has a profound impact on intestinal volume and cellular architecture. However, how intestinal homeostasis is maintained in fluctuating dietary conditions remains insufficiently understood. By utilizing the Drosophila midgut model, we reveal a novel stem cell intrinsic mechanism coupling cellular metabolism with stem cell extrinsic growth signal. Our results show that intestinal stem cells (ISCs) employ the hexosamine biosynthesis pathway (HBP) to monitor nutritional status. Elevated activity of HBP promotes Warburg effect-like metabolic reprogramming required for adjusting the ISC division rate according to nutrient content. Furthermore, HBP activity is an essential facilitator for insulin signaling-induced ISC proliferation. In conclusion, ISC intrinsic hexosamine synthesis regulates metabolic pathway activities and defines the stem cell responsiveness to niche-derived growth signals.

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HBP is a mediator of Drosophila midgut adaptation to nutrient content

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ISC intrinsic HBP is a necessary and sufficient driver of stem cell divisions

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HBP activity regulates a Warburg-like metabolic reprogramming of the intestine

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HBP activity determines the output of InR signaling of the ISCs

Excess body weight, weight gain and obesity-related cancer risk in women in Norway: the Norwegian Women and Cancer study

Background

Excess body weight and weight gain have been reported to independently increase the risk of several cancers. There are few published studies in nationally representative populations of women on specific, ‘obesity-related’ cancers in relation to prior weight change and relevant confounders.

Methods

Based on self-reported anthropometry, we prospectively assessed body mass index (BMI), weight change over 6 years and subsequent obesity-related cancer risk in the Norwegian Women and Cancer study. We used Cox proportional hazard models to calculate hazard ratios and restricted cubic splines to model potential non-linear dose–response relationships.

Results

Excess body weight increased the risk of overall obesity-related cancer, postmenopausal breast, colorectal, colon, endometrial and kidney cancer, with endometrial cancer showing a threefold elevated risk. High weight gain ( ≥ 10 kg) increased the risk of overall obesity-related cancer, postmenopausal breast, endometrial and pancreatic cancer. The association between high weight gain and pancreatic cancer was strong, with 91% increased risk.

Conclusions

Maintaining stable weight in middle adulthood, irrespective of BMI category at baseline, and avoiding excess body weight are both important in the prevention of several obesity-related cancers in women. Our finding of increased risk of pancreatic cancer in women with moderate and high weight gain is novel.

Time trends of incidence and mortality in colorectal cancer in Changning District, Shanghai, 1975-2013

OBJECTIVE

To evaluate the incidence and mortality of colorectal cancer (CRC) and the estimated patient's age, diagnostic duration and birth cohort effects in patients of Changning District, Shanghai.

METHODS

Age-standardized rates (ASRs) of CRC over eight intervals of 5 years from 1975 to 2013 were determined. Joinpoint regression analysis was used to determine the changes in annual incidence and mortality trends. Age-period-cohort analysis was performed to investigate their effects on the incidence and mortality trends of CRC.

RESULTS

For incidence, the ASRs of 14.14 per 100 000 and 11.81 per 100 000 during 1975-1979 increased to 32.11 per 100 000 and 26.25 per 100 000 in men and women during 2008-2013. For mortality, ASRs of 9.40 per 100 000 and 8.76 per 100 000 increased to 14.80 per 100 000 and 11.92 per 100 000 in men and women, respectively, from 1975-1979 to 2010-2013. Joinpoint regression analysis found an increasing incidence (average annual percentage change [AAPC] 2.18% for men and 1.65% for women) and mortality (AAPC 1.47% for men and 0.97% for women) of CRC throughout the entire period. The incidence and mortality trends of CRC were significantly affected by birth cohorts.

CONCLUSIONS

The increasing incidence and mortality of CRC are largely affected by the effects of birth cohorts. The increased incidence of CRC may be attributed to changes in lifestyle and diet, while that in mortality trends may be resulted from increasing incidence, an aging population and changing lifestyles.

Midlife weight gain is a risk factor for obesity-related cancer

Background

Overweight and diabetes are known cancer risk factors. This study examines independent and combined effects of weight gain and metabolic dysfunction during middle-adult years on obesity-related cancer risk.

Methods

Subjects (n = 3850) aged 45–69 years at exams 3–5 in the Framingham Offspring Study were classified according to current and prior (~14 years earlier) weight status, interim weight change and prevalent metabolic dysfunction. Cancer risk among subjects who were overweight at baseline and remained overweight, as well as those who became overweight during follow-up, was compared with risk among normal-weight individuals.

Results

Gaining ≥0.45 kg (≥1.0 pound)/year (vs. maintaining stable weight) over ~14 years increased cancer risk by 38% (95% confidence interval (CI), 1.09, 1.76); combined with metabolic dysfunction, weight gain increased cancer risk by 77% (95% CI, 1.21, 2.59). Compared with non-overweight adults, men and women who became overweight during midlife had 2.18-fold and 1.60-fold increased cancer risks; those who were overweight from baseline had non-statistically significant 28 and 33% increased cancer risks, respectively, despite having a midlife body mass index that was 3.4 kg/m² higher than those who gained weight later.

Conclusion

Midlife weight gain was a strong cancer risk factor. This excess risk was somewhat stronger among those with concurrent metabolic dysfunction.

Body mass index (BMI) trajectories and risk of colorectal cancer in the PLCO cohort

Obesity is correlated with increased colorectal cancer (CRC) risk, but few studies have investigated lifetime body mass index (BMI) metrics and CRC risk. In a cohort of 139 229 subjects in the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial, we analysed the effects of life-course BMI trajectories on CRC risk. At 13 years of follow-up, 2031 subjects developed CRC. Compared with subjects who were never overweight/obese, subjects who first exceeded the threshold of 25 kg m⁻² at age 20 had a higher CRC risk (HR = 1.28, 95% confidence interval (CI) = 1.11–1.48). A body weight gain of ≥15 kg between 20 and 50 years of age (HR = 1.34, 95% CI = 1.18–1.52) and baseline (HR = 1.24, 95% CI = 1.08–1.43) was significantly associated with increased CRC risk. BMI trajectory analyses revealed that the CRC risk increased gradually over the three BMI trajectories (HR = 1.11–1.27, P_trend = 0.005) compared with subjects who maintained a normal BMI. Being overweight/obese at the onset of adulthood and BMI trajectories over the lifespan that result in obesity lead to an increased CRC risk.

Changing trends in age and stage of colorectal cancer presentation in Ireland - From the nineties to noughties and beyond

BACKGROUND

Recent studies report incidence of colorectal (CRC) in younger adults (<50 years old) is increasing, and these patients are more likely to present with advanced disease. We performed a population-based analysis of these trends in an Irish population.

METHODS

A retrospective analysis was performed of all patients with histologically confirmed CRC in Ireland, using data from the National Cancer Registry of Ireland (NCRI) [1994-2012, inclusive]. Trends in age-adjusted CRC incidence and stage at presentation were tabulated. Total and average age-adjusted annual percentage change (APC) in CRC rates were calculated using regression analysis, with age adjusted to the European standard population for trend analysis.

RESULTS

A total of 39,528 cases were included. Throughout the entire study period the most common age of presentation was 70-79 years (32.5%, n = 12 829) with Stage II (27.5%, n = 10 851) CRC. Overall, an increase in incidence of CRC of 2.1% was observed. A significantly increased incidence in patients aged 20-29 years (APC = 9.17%; total change = 4.2%; p = 0.003) was identified from 1994 to 2012. Overall, in patients <50 years, the incidence of stage I colorectal cancer at presentation significantly reduced from 23.5% to 11.6% (p = 0.01). This was associated with a significant parallel rise in stage IV disease (11%-23%, p = 0.02) in this age group.

CONCLUSION

Increasing incidence of CRC in younger patient groups is observed in an Irish population, with an increase in advanced staged disease at presentation seen. Further studies should focus on identifying causality for this trend and identify potential targets for prevention going forward.

Changes in Adult BMI and Waist Circumference Are Associated with Increased Risk of Advanced Colorectal Neoplasia

BACKGROUND

Waist circumference (WC) is a stronger predictor of colon cancer (CRC) risk than body mass index (BMI). However, how well change in either WC or BMI predicts risk of advanced colorectal neoplasia (AN) is unclear.

AIMS

To determine the relationship between change in BMI and WC from early adulthood to later age and the risk of AN and which change measure is a stronger predictor.

METHODS

In 4500 adults, ages 50-80, with no previous neoplasia and undergoing screening colonoscopy, BMI and WC at age 21 and at time of screening were reported. Changes in BMI and WC were defined using universal risk cutoffs. Known CRC risk factors were controlled in the logistic models.

RESULTS

Overall, model statistics showed WC change (omnibus test χ ² = 10.15, 2 DF, p value = 0.006) was a statistically stronger predictor of AN than BMI change (omnibus test χ ² = 5.66, 5 DF, p value = 0.34). Independent of BMI change, participants who increased WC (OR 1.44; 95% CI 1.05-1.96) or maintained a high-risk WC (OR 2.50; 95% CI 1.38-4.53) at age 21 and at screening had an increased risk of AN compared to those with a low-risk WC. Study participants who were obese at age 21 and at screening had an increased risk of AN (OR 1.87; 95% CI 1.08-3.23) compared to those who maintained a healthy BMI. Maintaining an overweight BMI or increasing BMI was not associated with AN.

CONCLUSIONS

Maintaining an unhealthy BMI and WC throughout adult life may increase risk of AN. WC change may be a better predictor of AN than BMI change.

Metabolic Mediators of the Association Between Adult Weight Gain and Colorectal Cancer: Data From the European Prospective Investigation into Cancer and Nutrition (EPIC) Cohort

Evidence indicates that gaining weight in adult life is associated with an elevated risk of colorectal cancer; however, biological mechanisms that may explain this association remain unclear. We evaluated the mediation effect of 20 different biomarkers on the relationship between adult weight gain and colorectal cancer, using data from a prospective nested case-control study of 452 incident cases diagnosed between 1992 and 2003 and matched within risk sets to 452 controls within the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. The proportions of mediated effects (%) were estimated on the basis of differences in percent effect changes in conditional logistic regression models with and without additional adjustment for individual biomarkers. Greater adult weight gain (≥300 g/year vs. <300 g/year) was associated with a higher risk of colon cancer (multivariable-adjusted relative risk = 1.54, 95% confidence interval: 1.07, 2.24) but not rectal cancer (relative risk = 1.07, 95% confidence interval: 0.68, 1.66). This association was accounted for mostly by attained waist circumference (reduction of 61%) and by the biomarkers soluble leptin receptor (reduction of 43%) and glycated hemoglobin (reduction of 28%). These novel data suggest that the observed association between adult weight gain and colon cancer could be primarily explained by attained abdominal fatness and biomarkers of metabolic dysfunction.

Smoking at diagnosis significantly decreases 5-year cancer-specific survival in a population-based cohort of 18 166 colon cancer patients

BACKGROUND

Accumulating evidence suggests smoking may adversely affect cancer patients' outcomes. Previous studies of smoking and survival in colon cancer have been limited by size and/or lack of a population basis and results have been inconsistent.

AIM

To investigate in a large population-based cohort whether smoking status at diagnosis is an independent prognostic factor for cancer-specific survival in colon cancer and whether treatment modifies any impact of smoking.

METHODS

Colon adenocarcinomas diagnosed between 1994 and 2012 were abstracted from the National Cancer Registry Ireland, and classified by smoking status at diagnosis. Cancer-specific death rates over 5 years were compared in current, ex- and never smokers using multivariable Cox proportional hazards models, and subgroup analyses by treatment (combinations of cancer-directed surgery and chemotherapy) were conducted.

RESULTS

Of 18 166 colon cancers, 20% of patients were current smokers, 23% ex-smokers and 57% never smokers. Compared to never smokers, current smokers had a significantly raised cancer death rate [multivariable hazard ratio (HR) = 1.14, 95% CI: 1.07-1.12]. There was a significant interaction between treatment and smoking (P = 0.03). In those who had cancer-directed surgery only, but not other groups, current smokers had a significantly increased cancer death rate compared to never smokers (HR = 1.21, 95% CI: 1.09-1.34).

CONCLUSIONS

Smoking at diagnosis is an independent prognostic factor for colon cancer. The limitation of the association to surgically-treated patients suggests that the underlying mechanism(s) may be related to surgery. While further research is needed to elucidate mechanisms, continued efforts to encourage smoking prevention and cessation may yield benefits in terms of improved survival from colon cancer.

Bariatric Surgery Prior to Index Screening Colonoscopy Is Associated With a Decreased Rate of Colorectal Adenomas in Obese Individuals

Objectives:

Obesity is an important risk factor for the development of colorectal cancer (CRC). Although the impact of bariatric surgery on CRC is conflicting, its impact on precursor lesions is unknown. The aim of this study was to determine whether bariatric surgery before index screening colonoscopy is associated with decreased development of colorectal adenomas.

Methods:

We performed a retrospective cohort study of bariatric surgery patients who had undergone index, screening colonoscopy at an academic center from 2001 to 2014. Patients who had bariatric surgery at least 1 year before index colonoscopy were compared with those who had surgery after colonoscopy, using multivariable logistic regression to control for presurgical body mass index, sex, gender, race, type of surgery, aspirin use, metformin use, smoking, and age at colonoscopy.

Results:

One hundred and twenty-five obese individuals who had bariatric surgery before colonoscopy were compared with 223 individuals who had colonoscopy after surgery. Adenomatous polyps were found in 16.8% of individuals who had surgery first vs. 35.5% who had colonoscopy before bariatric surgery (unadjusted odds ratio (OR) 0.37, 95% confidence interval (CI): 0.21–0.64, P=0.0003). After multivariable adjustment, bariatric surgery before index screening colonoscopy was associated with a decreased risk of adenomas at index colonoscopy (adjusted OR 0.37, 95% CI: 0.19–0.69, P=0.002).

Conclusions:

Bariatric surgery is associated with a decreased risk of colorectal adenomas in obese individuals without a family history of CRC.

Analysis of Body Mass Index and Mortality in Patients With Colorectal Cancer Using Causal Diagrams

IMPORTANCE

Physicians and investigators have sought to determine the relationship between body mass index (BMI [calculated as weight in kilograms divided by height in meters squared]) and colorectal cancer (CRC) outcomes, but methodologic limitations including sampling selection bias, reverse causality, and collider bias have prevented the ability to draw definitive conclusions.

OBJECTIVE

To evaluate the association of BMI at the time of, and following, colorectal cancer (CRC) diagnosis with mortality in a complete population using causal diagrams.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective observational study with prospectively collected data included a cohort of 3408 men and women, ages 18 to 80 years, from the Kaiser Permanente Northern California population, who were diagnosed with stage I to III CRC between 2006 and 2011 and who also had surgery.

EXPOSURES

Body mass index at diagnosis and 15 months following diagnosis.

MAIN OUTCOMES AND MEASURES

Hazard ratios (HRs) for all-cause mortality and CRC-specific mortality compared with normal-weight patients, adjusted for sociodemographics, disease severity, treatment, and prediagnosis BMI.

RESULTS

This study investigated a cohort of 3408 men and women ages 18 to 80 years diagnosed with stage I to III CRC between 2006 and 2011 who also had surgery. At-diagnosis BMI was associated with all-cause mortality in a nonlinear fashion, with patients who were underweight (BMI <18.5; HR, 2.65; 95% CI, 1.63-4.31) and patients who were class II or III obese (BMI ≥35; HR, 1.33; 95% CI, 0.89-1.98) exhibiting elevated mortality risks, compared with patients who were low-normal weight (BMI 18.5 to <23). In contrast, patients who were high-normal weight (BMI 23 to <25; HR, 0.77; 95% CI, 0.56-1.06), low-overweight (BMI 25 to <28; HR, 0.75; 95% CI, 0.55-1.04), and high-overweight (BMI 28 to <30; HR, 0.52; 95% CI, 0.35-0.77) had lower mortality risks, and patients who were class I obese (BMI 30 to <35) showed no difference in risk. Spline analysis confirmed a U-shaped relationship in participants with lowest mortality at a BMI of 28. Associations with CRC-specific mortality were similar. Associations of postdiagnosis BMI and mortality were also similar, but patients who were class I obese had significantly lower all-cause and cancer-specific mortality risks.

CONCLUSIONS AND RELEVANCE

In this study, body mass index at the time of diagnosis and following diagnosis of CRC was associated with mortality risk. Though evidence shows that exercise in patients with cancer should be encouraged, findings suggest that recommendations for weight loss in the immediate postdiagnosis period among patients with CRC who are overweight may be unwarranted.

Anticancer effect of icaritin inhibits cell growth of colon cancer through reactive oxygen species, Bcl-2 and cyclin D1/E signaling

Icaritin has an advantage in enhancing immunity. Besides, with its anticancer effect, it may be of great help in cancer treatment and recovery of cancer patients. As a result, icaritin is likely to become a novel anticancer drug. However, the anticancer effect of icaritin against colon cancer has not been elucidated thus far. The present study investigated the latent anticancer effect of icaritin on the inhibition of colon cancer cell growth by regulating reactive oxygen species (ROS), B-cell lymphoma (Bcl)-2 and cyclin D1/E signaling. The COLO-205 colon cancer cell line was used as a colon cancer cell model in the present study. First, cell growth and apoptosis were measured to analyze the anticancer effect of icaritin against colon cancer. Next, the possible mechanism of icaritin against colon cancer, including ROS, Bcl-2, cyclin D1, cyclin E and caspase-3/9, was explored. The results revealed that icaritin could inhibit cell growth and induce the apoptosis of COLO-205 cells. In addition, icaritin significantly induced ROS generation, suppressed Bcl-2, cyclin D1 and cyclin E protein expression, and activated caspase-3/9 activity in COLO-205 cells. The present findings demonstrated that icaritin exerted antiproliferative and anticancer effects against colon cancer through the activation of ROS generation and the suppression of Bcl-2, cyclin D1 and cyclin E signaling.

The impact of body weight gain on nonalcoholic fatty liver disease and metabolic syndrome during earlier and later adulthood

AIM

Body weight gain adds risk for metabolic disorders and there are different metabolic changes in earlier and later adulthood. However, its impact on non-alcoholic fatty liver disease (NAFLD) was indeterminate. The aim of current study was to evaluate the impact of body weight gain on NAFLD and metabolic syndrome (MetS) during overall, earlier (25-40y) and later (over 40y) adulthood.

METHODS

1119 subjects were selected to calculate changes in body weight (ΔBW), body mass index (BMI) (ΔBMI) and bodyweight per year (ΔBW/y) to analysis their impact on NAFLD and MetS in multi-variable regression models, and explored the potential mediators that associated ΔBMI with NAFLD by mediation analysis.

RESULTS

ΔBMI, ΔBW and ΔBW/y in whole adulthood were all positively associated with NAFLD and MetS. Body weight gain during earlier adulthood was more strongly associated with NAFLD than those during later adulthood. In NAFLD, the ORs of ΔBMI (third trisection), ΔBW and ΔBW/y were 3.86 (2.25, 6.57), 1.05 (1.02, 1.09) and 2.05 (1.29, 3.24) during earlier adulthood, and 1.47 (1.09, 2.02), 1.02 (1.00, 1.06), and 1.04 (.99, 1.13) over 40y. Insulin and HOMA-IR were important intermediates that associated ΔBMI with NAFLD. ΔBMI in earlier adulthood increased higher insulin and insulin resistance (IR) than later adulthood.

CONCLUSIONS

Body weight gain in adulthood was positively associated with NAFLD and MetS, and the association was stronger in earlier than later adulthood. Insulin and IR were important mediators that contributed to the association.

Obesity and cancer: An update of the global impact

In view of the growing global obesity epidemic, this paper reviews the relation between recent trends in body mass index (BMI) and the changing profile of cancer worldwide. By examining seven selected countries, each representing a world region, a pattern of increasing BMI with region and gender-specific diversity is noted: increasing levels of BMI were most pronounced in the Middle East (Saudi Arabia), rather modest in Eastern Asia (India) and generally more rapid in females than in males. This observation translates into a disproportionate distribution of cancer attributable to high levels of BMI, ranging by sex from 4-9% in Saudi Arabia and from 0.2-1.2% in India. Overweight and obesity may also influence cancer outcomes, and hence have a varying impact on cancer survival and death in different world regions. Future challenges in cancer studies exploring the association with overweight and obesity concern the measurement of adiposity and its potentially cumulative effect over the life course. Given the limitations of BMI as an imperfect measure of body fatness, routine anthropometric data collection needs to be extended to develop more informative measures, such as waist circumference in settings where the gold standard tools remain unaffordable. Furthermore, questions surrounding the dose-response and timing of obesity and their associations with cancer remain to be answered. Improved surveillance of health risk factors including obesity as well as the scale and profile of cancer in every country of the world is urgently needed. This will enable the design of cost-effective actions to curb the growing burden of cancer related to excess body weight.

Annual Average Changes in Adult Obesity as a Risk Factor for Papillary Thyroid Cancer: A Large-Scale Case-Control Study

We evaluated the association between weight change in middle-aged adults and papillary thyroid cancer (PTC) based on a large-scale case-control study. Our study included data from 1551 PTC patients (19.3% men and 80.7% women) who underwent thyroidectomy at the 3 general hospitals in Korea and 15,510 individually matched control subjects. The subjects' weight history, epidemiologic information, and tumor characteristics confirmed after thyroidectomy were analyzed. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were determined for the annual average changes in weight and obesity indicators (body mass index (BMI), body surface area, and body fat percentage (BF%) in subjects since the age of 35 years. Subjects with a total weight gain ≥10 kg after age 35 years were more likely to have PTC (men, OR, 5.39, 95% CI, 3.88-7.49; women, OR, 3.36, 95% CI, 2.87-3.93) compared with subjects with a stable weight (loss or gain <5 kg). A marked increase in BMI since age 35 years (annual average change of BMI ≥0.3 kg/m/yr) was related to an elevated PTC risk, and the association was more pronounced for large-sized PTC risks (<1 cm, OR, 2.34, 95% CI, 1.92-2.85; ≥1 cm, OR, 4.00, 95% CI, 2.91-5.49, P heterogeneity = 0.005) compared with low PTC risks. Weight gain and annual increases in obesity indicators in middle-aged adults may increase the risk of developing PTC.

Can diet and lifestyle prevent breast cancer: what is the evidence?

Breast cancer is the most common cancer among women in both developed and less-developed countries. Rates of breast cancer are increasing worldwide, with a particular increase in postmenopausal and estrogen receptor-positive cases. The World Cancer Research Fund (WCRF) and American Cancer Society (ACS) cancer prevention guidelines recommend maintaining a healthy weight, undertaking at least 150 minutes of moderate intensity exercise per week, limiting alcohol consumption, and eating a plant-based diet. Observational data link adherence to physical activity and alcohol guidelines throughout life to a reduced risk of developing pre- and postmenopausal breast cancer. Weight control throughout life appears to prevent cases after menopause. Adherence to a healthy dietary pattern does not have specific effects on breast cancer risk but remains important as it reduces the risk for other common diseases, such as cardiovascular disease (CVD), diabetes, and dementia. Emerging data suggest that smoking during adolescence or early adulthood increases later risk of breast cancer. Lifestyle factors appear to modify risk among high-risk women with a family history and those with typical risk of the general population, although their effects among carriers of BRCA mutations are not well defined. Recent expert reports estimate that successful lifestyle changes could prevent 25% to 30% of cases of breast cancer. These reductions will only be achieved if we can implement targeted prevention programs for high-risk women and women in population-based breast screening programs during childhood, adolescence, and early adulthood when the rapidly developing breast is particularly susceptible to carcinogenesis.

Imbalanced insulin action in chronic over nutrition: Clinical harm, molecular mechanisms, and a way forward

The growing worldwide prevalence of overnutrition and underexertion threatens the gains that we have made against atherosclerotic cardiovascular disease and other maladies. Chronic overnutrition causes the atherometabolic syndrome, which is a cluster of seemingly unrelated health problems characterized by increased abdominal girth and body-mass index, high fasting and postprandial concentrations of cholesterol- and triglyceride-rich apoB-lipoproteins (C-TRLs), low plasma HDL levels, impaired regulation of plasma glucose concentrations, hypertension, and a significant risk of developing overt type 2 diabetes mellitus (T2DM). In addition, individuals with this syndrome exhibit fatty liver, hypercoagulability, sympathetic overactivity, a gradually rising set-point for body adiposity, a substantially increased risk of atherosclerotic cardiovascular morbidity and mortality, and--crucially--hyperinsulinemia. Many lines of evidence indicate that each component of the atherometabolic syndrome arises, or is worsened by, pathway-selective insulin resistance and responsiveness (SEIRR). Individuals with SEIRR require compensatory hyperinsulinemia to control plasma glucose levels. The result is overdrive of those pathways that remain insulin-responsive, particularly ERK activation and hepatic de-novo lipogenesis (DNL), while carbohydrate regulation deteriorates. The effects are easily summarized: if hyperinsulinemia does something bad in a tissue or organ, that effect remains responsive in the atherometabolic syndrome and T2DM; and if hyperinsulinemia might do something good, that effect becomes resistant. It is a deadly imbalance in insulin action. From the standpoint of human health, it is the worst possible combination of effects. In this review, we discuss the origins of the atherometabolic syndrome in our historically unprecedented environment that only recently has become full of poorly satiating calories and incessant enticements to sit. Data are examined that indicate the magnitude of daily caloric imbalance that causes obesity. We also cover key aspects of healthy, balanced insulin action in liver, endothelium, brain, and elsewhere. Recent insights into the molecular basis and pathophysiologic harm from SEIRR in these organs are discussed. Importantly, a newly discovered oxide transport chain functions as the master regulator of the balance amongst different limbs of the insulin signaling cascade. This oxide transport chain--abbreviated 'NSAPP' after its five major proteins--fails to function properly during chronic overnutrition, resulting in this harmful pattern of SEIRR. We also review the origins of widespread, chronic overnutrition. Despite its apparent complexity, one factor stands out. A sophisticated junk food industry, aided by subsidies from willing governments, has devoted years of careful effort to promote overeating through the creation of a new class of food and drink that is low- or no-cost to the consumer, convenient, savory, calorically dense, yet weakly satiating. It is past time for the rest of us to overcome these foes of good health and solve this man-made epidemic.

Obesity promotes colonic stem cell expansion during cancer initiation

There is an urgent need to elucidate the mechanistic links between obesity and colon cancer. Convincing evidence for the role of Lgr5(+) stem cells in colon tumorigenesis has been established; however, the influence of obesity on stem cell maintenance is unknown. We assessed the effects of high fat (HF) feeding on colonic stem cell maintenance during cancer initiation (AOM induced) and the responsiveness of stem cells to adipokine signaling pathways. The number of colonic GFP(+) stem cells was significantly higher in the AOM-injected HF group compared to the LF group. The Lgr5(+) stem cells of the HF fed mice exhibited statistically significant increases in cell proliferation and decreases in apoptosis in response to AOM injection compared to the LF group. Colonic organoid cultures from lean mice treated with an adiponectin receptor agonist exhibited a reduction in Lgr5-GPF(+) stem cell number and an increase in apoptosis; however, this response was diminished in the organoid cultures from obese mice. These results suggest that the responsiveness of colonic stem cells to adiponectin in diet-induced obesity is impaired and may contribute to the stem cell accumulation observed in obesity.

Body weight gain and risk of colorectal cancer: a systematic review and meta-analysis of observational studies

While the relationship between body mass index as an indicator of excess body weight and the risk of colorectal cancer (CRC) is well established, the association between body weight gain in adulthood and risk of CRC remains unresolved. We quantified this association in a meta-analysis of 12 observational studies published until November 2014 with a total of 16,151 incident CRC cases. Random effect models were used to obtain summary relative risks (RR) and 95% confidence intervals (95% CIs). Between-study heterogeneity was assessed using I(2) statistics. Overall, the summary RR (95% CI) was 1.22 (1.14-1.30) for high body weight gain (midpoint: 15.2 kg) compared with stable weight (P for heterogeneity = 0.182; I(2) = 21.2%). In a dose-response analysis, each 5 kg weight gain was associated with a 4% (95% CI: 2%-5%) higher risk of CRC. The association persisted after adjustment for body weight at younger age and was present for both men and women, as well as for colon and rectal cancer. Differences by sex were detected for colon cancer (P for interaction = 0.003, with higher risk for men than women), but not for rectal cancer (P for interaction = 0.613). In conclusion, these data underscore the importance of body weight management from early adulthood onwards for the prevention of CRC development.

Colorectal Cancer Classification and Cell Heterogeneity: A Systems Oncology Approach

Colorectal cancer is a heterogeneous disease that manifests through diverse clinical scenarios. During many years, our knowledge about the variability of colorectal tumors was limited to the histopathological analysis from which generic classifications associated with different clinical expectations are derived. However, currently we are beginning to understand that under the intense pathological and clinical variability of these tumors there underlies strong genetic and biological heterogeneity. Thus, with the increasing available information of inter-tumor and intra-tumor heterogeneity, the classical pathological approach is being displaced in favor of novel molecular classifications. In the present article, we summarize the most relevant proposals of molecular classifications obtained from the analysis of colorectal tumors using powerful high throughput techniques and devices. We also discuss the role that cancer systems biology may play in the integration and interpretation of the high amount of data generated and the challenges to be addressed in the future development of precision oncology. In addition, we review the current state of implementation of these novel tools in the pathological laboratory and in clinical practice.

Weight change and risk of colorectal cancer: a systematic review and meta-analysis

Results from cohort studies of adult weight gain and risk of colorectal cancer are inconsistent. We conducted a systematic review and meta-analysis of prospective studies assessing the association of change in weight/body mass index with colorectal cancer risk. We searched Scopus and Web of Science up to June 2014 and supplemented the search with manual searches of the reference lists of the identified articles. Thirteen studies published between 1997 and 2014 were pooled by using a random-effects model, and potential heterogeneity was explored by fitting meta-regression models. The highest weight gain category, measured by weight/body mass index, compared with a reference category, was associated with increased risk of colorectal cancer (hazard ratio (HR) = 1.16, 95% confidence interval (CI): 1.08, 1.24), whereas no association was found for weight loss (HR = 0.96, 95% CI: 0.89, 1.05). There was no suggestion of heterogeneity across studies. For dose response, a 5-kg weight gain was associated with a slightly increased risk of colorectal cancer (HR = 1.03, 95% CI: 1.02, 1.05), with some heterogeneity observed (I(2) = 42%; P = 0.02), which was partially explained by sex (ratio of HRs = 1.03, 95% CI: 1.00, 1.07). In this meta-analysis, gain in weight/body mass index was positively associated with colorectal cancer risk.

Body fatness as a cause of cancer: epidemiologic clues to biologic mechanisms

Carrying excess body fat is a leading cause of cancer. Epidemiologic evidence gives strong clues about the mechanisms that link excess adiposity to risk for several cancer sites. For postmenopausal breast cancer and endometrial cancer, the hyper-estrogenic state that is induced by excess body fatness is the likely cause. For esophageal cancer and gallbladder cancer, chronic local inflammation induced by acid reflux and gallstones is the likely cause, and for liver cancer, local inflammation induced by hepatic fatty infiltration is the likely cause. However, for several other cancers known to be associated with excess adiposity, including cancers of the colon, pancreas, ovary, kidney, and prostate, specific causes are not known. Possible candidates include elevated systemic or local tissue inflammation induced by adiposity and effects of the elevated levels of leptin, insulin, IGFs, and depressed immune function that are seen with excess adiposity. There is growing evidence that intentional weight loss not only reduces circulating levels of cancer-associated factors but that it also reduces cancer incidence and recurrence. Better research is needed to understand the mechanisms that link excess body fat to cancer risk as well as to understand the amount of weight loss needed for substantial cancer risk reduction. Finally, as we develop better understanding of the mediators of the effects of excess body fatness on cancer risk, we should identify pharmacologic interventions that target those mediators so that they can be used to complement weight loss in order to reduce cancer risk.

Adulthood Weight Change and Risk of Colorectal Cancer in the Nurses' Health Study and Health Professionals Follow-up Study

We investigated the association between adulthood weight change and colorectal cancer risk in a prospective study with 24 to 34 years of follow-up among 90,988 women and 46,679 men. The primary exposures included weight change from early adulthood (age = 18 years for women, 21 years for men) to baseline enrollment (median age = 43 years for women, 52 years for men), and from baseline to present. In the secondary analyses, we also assessed 4-year weight change during follow-up, and during premenopausal (from age 18 years to menopause) and postmenopausal (from menopause to present) periods in women. Compared to men maintaining their weight from age 21 to baseline, those who gained 20 kg or more were at a higher risk of colorectal cancer (relative risk [RR], 1.64; 95% confidence interval [CI], 1.15-2.35, Ptrend < 0.001), whereas those who lost 8 kg or more had a lower risk (RR, 0.61; 95% CI, 0.30-1.22, Ptrend = 0.003). Similar but weaker associations were found in women and the corresponding RRs were 1.38 (95% CI, 1.13-1.69, Ptrend < 0.001) and 0.80 (95% CI, 0.58-1.09, Ptrend = 0.21). Weight change from baseline to present was not associated with colorectal cancer risk. Four-year weight change during follow-up was positively associated with colorectal cancer risk in men (Ptrend = 0.03) but not in women (Ptrend = 0.42). In addition, in women, weight change before, but not after, menopause was associated with colorectal cancer risk. Our findings provide further scientific rationale for recommendations to maintain a healthy body weight during adulthood. A potential differential association according to sex and timing of weight change warrants further investigation.

Increasing disparities in the age-related incidences of colon and rectal cancers in the United States, 1975-2010

IMPORTANCE

The overall incidence of colorectal cancer (CRC) has been decreasing since 1998 but there has been an apparent increase in the incidence of CRC in young adults.

OBJECTIVE

To evaluate age-related disparities in secular trends in CRC incidence in the United States.

DESIGN, SETTING, AND PATIENTS

A retrospective cohort study using the Surveillance, Epidemiology, and End Results (SEER) CRC registry. Age at diagnosis was analyzed in 15-year intervals starting at the age of 20 years. SEER*Stat was used to obtain the annual cancer incidence rates, annual percentage change, and corresponding P values for the secular trends. Data were obtained from the National Cancer Institute's SEER registry for all patients diagnosed as having colon or rectal cancer from January 1, 1975, through December 31, 2010 (N = 393 241).

MAIN OUTCOME AND MEASURE

Difference in CRC incidence by age.

RESULTS

The overall age-adjusted CRC incidence rate decreased by 0.92% (95% CI, -1.14 to -0.70) between 1975 and 2010. There has been a steady decline in the incidence of CRC in patients age 50 years or older, but the opposite trend has been observed for young adults. For patients 20 to 34 years, the incidence rates of localized, regional, and distant colon and rectal cancers have increased. An increasing incidence rate was also observed for patients with rectal cancer aged 35 to 49 years. Based on current trends, in 2030, the incidence rates for colon and rectal cancers will increase by 90.0% and 124.2%, respectively, for patients 20 to 34 years and by 27.7% and 46.0%, respectively, for patients 35 to 49 years.

CONCLUSIONS AND RELEVANCE

There has been a significant increase in the incidence of CRC diagnosed in young adults, with a decline in older patients. Further studies are needed to determine the cause for these trends and identify potential preventive and early detection strategies.

Adult weight gain and adiposity-related cancers: a dose-response meta-analysis of prospective observational studies

BACKGROUND

Adiposity, measured by body mass index, is implicated in carcinogenesis. While adult weight gain has diverse advantages over body mass index in measuring adiposity, systematic reviews on adult weight gain in relation to adiposity-related cancers are lacking.

METHODS

PubMed and Embase were searched through September 2014 for prospective observational studies investigating the relationship between adult weight gain and the risk of 10 adiposity-related cancers. Dose-response meta-analyses were performed using a random-effects model to estimate summary relative risk (RR) and 95% confidence interval (CI) for each cancer type. All statistical tests were two-sided.

RESULTS

A total of 50 studies were included. For each 5 kg increase in adult weight gain, the summary relative risk was 1.11 (95% CI = 1.08 to 1.13) for postmenopausal breast cancer among no- or low-hormone replacement therapy (HRT) users, 1.39 (95% CI = 1.29 to 1.49) and 1.09 (95% CI = 1.02 to 1.16) for postmenopausal endometrial cancer among HRT nonusers and users, respectively, 1.13 (95% CI = 1.03 to 1.23) for postmenopausal ovarian cancer among no or low HRT users, 1.09 (95% CI = 1.04 to 1.13) for colon cancer in men. The relative risk of kidney cancer comparing highest and lowest level of adult weight gain was 1.42 (95% CI = 1.11 to 1.81). Adult weight gain was unrelated to cancers of the breast (premenopausal women, postmenopausal HRT users), prostate, colon (women), pancreas, and thyroid. An increase in risk associated with adult weight gain for breast cancer was statistically significantly greater among postmenopausal women (P(heterogeneity) = .001) and HRT nonusers (P(heterogeneity) = .001); that for endometrial cancer was alike among HRT nonusers (P(heterogeneity) = .04).

CONCLUSIONS

Avoiding adult weight gain itself may confer protection against certain types of cancers, particularly among HRT nonusers.

Dietary glycemic index and glycemic load and risk of colorectal cancer: results from the EPIC-Italy study

A carbohydrate-rich diet, resulting in high blood glucose and insulin, has been hypothesized as involved in colorectal cancer etiology. We investigated dietary glycemic index (GI) and glycemic load (GL), in relation to colorectal cancer, in the prospectively recruited EPIC-Italy cohort. After a median 11.7 years, 421 colorectal cancers were diagnosed among 47,749 recruited adults. GI and GL were estimated from validated food frequency questionnaires. Multivariable Cox modeling estimated hazard ratios (HRs) for associations between colorectal cancer and intakes of total, high GI and low GI carbohydrate and GI and GL. The adjusted HR of colorectal cancer for highest versus lowest GI quartile was 1.35; 95% confidence interval (CI) 1.03-1.78; p trend 0.031. Increasing high GI carbohydrate intake was also significantly associated with increasing colorectal cancer risk (HR 1.45; 95% CI 1.04-2.03; p trend 0.034), whereas increasing low GI carbohydrate was associated with reducing risk (HR 0.73; 95% CI 0.54-0.98; p trend 0.033). High dietary GI and high GI carbohydrate were associated with increased risks of cancer at all colon sites (HR 1.37; 95% CI 1.00-1.88, HR 1.80; 95% CI 1.22-2.65, respectively), whereas high GI carbohydrate and high GL were associated with increased risk of proximal colon cancer (HR 1.94; 95% CI 1.18-3.16, HR 2.01; 95% CI 1.08-3.74, respectively). After stratification for waist-to-hip ratio (WHR), cancer was significantly associated with GI, and high GI carbohydrate, in those with high WHR. These findings suggest that high dietary GI and high carbohydrate intake from high GI foods are associated with increased risk of colorectal cancer.

Association between adult weight gain and colorectal cancer: a dose-response meta-analysis of observational studies

This study investigated the association between adult weight gain and risk of colorectal cancer (CRC). Using terms related to weight gain and CRC, we searched PubMed, Embase and Web of Science for relevant studies published before June 2014. Two evaluators independently selected studies according to the selection criteria, and eight studies were included (three case-control and five cohort studies). Summary estimates were obtained using fixed- or random-effects models. The relative risk (RR) of the association between adult weight gain and CRC was 1.25 (95% confidence interval [CI], 1.10-1.43); the RR was 1.30 (95% CI, 1.14-1.49) for colon cancer (CC) and 1.27 (95% CI, 1.02-1.58) for rectal cancer (RC) for the highest versus lowest category. For every 5-kg increase in adult weight, the risk increased by 5% (RR, 1.05; 95% CI, 1.02-1.09) for CRC, 6% (RR, 1.06; 95% CI, 1.02-1.11) for CC and 6% (RR, 1.06; 95% CI, 1.03-1.08) for RC. The subgroup analyses showed a positive association between adult weight gain and risk of CRC only in men, and the RR was 1.65 (95% CI, 1.42-1.92) for the highest versus lowest category of adult weight gain and 1.10 (95% CI, 1.06-1.15) for a 5-kg increase in adult weight. In conclusion, there is evidence that adult weight gain is associated with an increased risk of CRC. However, the positive association between adult weight gain and risk of CRC is stronger among men than among women.

Obesity and colorectal cancer: Role of adipokines in tumor initiation and progression

Obesity-associated diseases account for a large portion of public health challenges. Among obesity-related disorders, a direct and independent relationship has been ascertained for colorectal cancer (CRC). The evidence that adipocyte hypertrophy and excessive adipose tissue accumulation (mainly visceral) can promote pathogenic adipocyte and adipose tissue-related diseases, has led to formulate the concept of “adiposopathy”, defined as adipocyte and adipose tissue dysfunction that contributes to metabolic syndrome. Adipose tissue can, indeed, be regarded as an important and highly active player of the innate immune response, in which cytokine/adipokine secretion is responsible for a paracrine loop between adipocytes and macrophages, thus contributing to the systemic chronic low-grade inflammation associated with visceral obesity, which represents a favorable niche for tumor development. The adipocyte itself participates as a central mediator of this inflammatory response in obese individuals by secreting hormones, growth factors and proinflammatory cytokines, which are of particular relevance for the pathogenesis of CRC. Among adipocyte-secreted hormones, the most relevant to colorectal tumorigenesis are adiponectin, leptin, resistin and ghrelin. All these molecules have been involved in cell growth and proliferation, as well as tumor angiogenesis and it has been demonstrated that their expression changes from normal colonic mucosa to adenoma and adenocarcinoma, suggesting their involvement in multistep colorectal carcinogenesis. These findings have led to the hypothesis that an unfavorable adipokine profile, with a reduction of those with an anti-inflammatory and anti-cancerous activity, might serve as a prognostic factor in CRC patients and that adipokines or their analogues/antagonists might become useful agents in the management or chemoprevention of CRC.