Adolescent body mass index and risk of colon and rectal cancer in a cohort of 1.79 million Israeli men and women: A population-based study

Early-Onset Colorectal Cancer: Prevalence, Risk Factors, and Clinical Features Among Commercially Insured Adults in the United States

BACKGROUND

 The incidence of colorectal cancer (CRC) in patients younger than 50 has been rising over the last several decades, accounting for up to 25% of total cases. Despite the screening age recently being lowered to 45, a significant proportion of cases would still arise at younger ages prior to screening. Nonfamilial early-onset CRC remains a particular concern. Identification of risk factors and clinical features in this age group is needed to improve detection.

METHODS

In this retrospective cohort analysis using claims data from the Truven Health MarketScan® Commercial Claims insurance database from 2007 to 2017, patients were identified with colon and rectal cancer, compared across three age groups (ages 18-40, 40-50, and >50), and analyzed for risk factors and clinical features.

RESULTS

Female sex was more prevalent in the younger age group compared to age >50 (54% and 51.9% vs. 49.6%), with little change noted between rectal cancer age groups by sex. A higher percentage of younger patients were in the obese age groups compared with older groups for colon cancer, particularly the morbidly obese with BMI >40 (24.94%, 25.75%, and 21.34% in the three age groups). Abdominal pain was a common presenting symptom identified in the age groups <50 compared with age >50 (25% and 19% vs. 14%), along with hematochezia, weight loss, and anemia.

CONCLUSIONS

Morbid obesity and female sex may be important risk factors among patients with early-onset CRC. The presence of abdominal pain was more common among the early-onset CRC cohort.

High-fat diet plus HNF1A variant promotes polyps by activating β-catenin in early-onset colorectal cancer

The incidence of early-onset colorectal cancer (EO-CRC) is rising and is poorly understood. Lifestyle factors and altered genetic background possibly contribute. Here, we performed targeted exon sequencing of archived leukocyte DNA from 158 EO-CRC participants, which identified a missense mutation at p.A98V within the proximal DNA binding domain of Hepatic Nuclear Factor 1 α (HNF1AA98V, rs1800574). The HNF1AA98V exhibited reduced DNA binding. To test function, the HNF1A variant was introduced into the mouse genome by CRISPR/Cas9, and the mice were placed on either a high-fat diet (HFD) or high-sugar diet (HSD). Only 1% of the HNF1A mutant mice developed polyps on normal chow; however, 19% and 3% developed polyps on the HFD and HSD, respectively. RNA-Seq revealed an increase in metabolic, immune, lipid biogenesis genes, and Wnt/β-catenin signaling components in the HNF1A mutant relative to the WT mice. Mouse polyps and colon cancers from participants carrying the HNF1AA98V variant exhibited reduced CDX2 and elevated β-catenin proteins. We further demonstrated decreased occupancy of HNF1AA98V at the Cdx2 locus and reduced Cdx2 promoter activity compared with WT HNF1A. Collectively, our study shows that the HNF1AA98V variant plus a HFD promotes the formation of colonic polyps by activating β-catenin via decreasing Cdx2 expression.

Obesity indices as risk factor for colorectal cancer in patients at a national police hospital in Peru

<b>Introduction: </b>Colorectal cancer (CRC) represents the third most diagnosed form of cancer around the world, accounting for 11% of all cancer diagnoses. It has been seen that obesity is closely linked to this disease.<br /> <b>Materials and methods: </b>This study is a non-paired case-control study. To measure obesity, the body mass index (BMI), new body mass index (NBMI), and the triponderal index (TPI) were used. Logistic regression was used to obtain the adjusted odds ratio (aOR) by age and sex, confidence interval (95%CI).<br /> <b>Results: </b>The sample was 246 patients. The prevalence of obesity according to BMI was 12.20%. The multivariable analysis found statistically significant association between CRC and obesity according to BMI (aOR: 3.23; 95% CI 1.26-8.30) compared to normal weight; NBMI tertile 3 (aOR: 4.02; 95% CI 1.95-8.30), compared to tertile 1; and TPI tertile 3 (aOR: 4.55; 95% CI 2.21-9.35) versus tertile 1.<br /> <b>Conclusions: </b>Obesity, is a risk factor for CRC. Future studies might consider useful different ways to measure obesity to define population strata with a higher-risk of CRC.

Colorectal cancer statistics, 2023

Colorectal cancer (CRC) is the second most common cause of cancer death in the United States. Every 3 years, the American Cancer Society provides an update of CRC statistics based on incidence from population-based cancer registries and mortality from the National Center for Health Statistics. In 2023, approximately 153,020 individuals will be diagnosed with CRC and 52,550 will die from the disease, including 19,550 cases and 3750 deaths in individuals younger than 50 years. The decline in CRC incidence slowed from 3%-4% annually during the 2000s to 1% annually during 2011-2019, driven partly by an increase in individuals younger than 55 years of 1%-2% annually since the mid-1990s. Consequently, the proportion of cases among those younger than 55 years increased from 11% in 1995 to 20% in 2019. Incidence since circa 2010 increased in those younger than 65 years for regional-stage disease by about 2%-3% annually and for distant-stage disease by 0.5%-3% annually, reversing the overall shift to earlier stage diagnosis that occurred during 1995 through 2005. For example, 60% of all new cases were advanced in 2019 versus 52% in the mid-2000s and 57% in 1995, before widespread screening. There is also a shift to left-sided tumors, with the proportion of rectal cancer increasing from 27% in 1995 to 31% in 2019. CRC mortality declined by 2% annually from 2011-2020 overall but increased by 0.5%-3% annually in individuals younger than 50 years and in Native Americans younger than 65 years. In summary, despite continued overall declines, CRC is rapidly shifting to diagnosis at a younger age, at a more advanced stage, and in the left colon/rectum. Progress against CRC could be accelerated by uncovering the etiology of rising incidence in generations born since 1950 and increasing access to high-quality screening and treatment among all populations, especially Native Americans.

Is the association of overweight and obesity with colorectal cancer underestimated? An umbrella review of systematic reviews and meta-analyses

Although high body-mass index (BMI) is associated with increased risk of developing colorectal cancer (CRC), many CRC patients lose weight before diagnosis. BMI is often reported close to diagnosis, which may have led to underestimation or even reversal of direction of the BMI-CRC association. We aimed to assess if and to what extent potential bias from prediagnostic weight loss has been considered in available epidemiological evidence. We searched PubMed and Web of Science until May 2022 for systematic reviews and meta-analyses investigating the BMI-CRC association. Information on design aspects and results was extracted, including if and how the reviews handled prediagnostic weight loss as a potential source of bias. Additionally, we analyzed how individual cohort studies included in the latest systematic review handled the issue. Overall, 18 reviews were identified. None of them thoroughly considered or discussed prediagnostic weight loss as a potential source of bias. The majority (15/21) of cohorts included in the latest review did not exclude any initial years of follow-up from their main analysis. Although the majority of studies reported having conducted sensitivity analyses in which initial years of follow-up were excluded, results were reported very heterogeneously and mostly for additional exclusions of 1-2 years only. Where explicitly reported, effect estimates mostly increased with increasing length of exclusion. The impact of overweight and obesity on CRC risk may be larger than suggested by the existing epidemiological evidence.

Separating the effects of early and later life adiposity on colorectal cancer risk: a Mendelian randomization study

BACKGROUND

Observational studies have linked childhood obesity with elevated risk of colorectal cancer; however, it is unclear if this association is causal or independent from the effects of obesity in adulthood on colorectal cancer risk.

METHODS

We conducted Mendelian randomization (MR) analyses to investigate potential causal relationships between self-perceived body size (thinner, plumper, or about average) in early life (age 10) and measured body mass index in adulthood (mean age 56.5) with risk of colorectal cancer. The total and independent effects of body size exposures were estimated using univariable and multivariable MR, respectively. Summary data were obtained from a genome-wide association study of 453,169 participants in UK Biobank for body size and from a genome-wide association study meta-analysis of three colorectal cancer consortia of 125,478 participants.

RESULTS

Genetically predicted early life body size was estimated to increase odds of colorectal cancer (odds ratio [OR] per category change: 1.12, 95% confidence interval [CI]: 0.98-1.27), with stronger results for colon cancer (OR: 1.16, 95% CI: 1.00-1.35), and distal colon cancer (OR: 1.25, 95% CI: 1.04-1.51). After accounting for adult body size using multivariable MR, effect estimates for early life body size were attenuated towards the null for colorectal cancer (OR: 0.97, 95% CI: 0.77-1.22) and colon cancer (OR: 0.97, 95% CI: 0.76-1.25), while the estimate for distal colon cancer was of similar magnitude but more imprecise (OR: 1.27, 95% CI: 0.90-1.77). Genetically predicted adult life body size was estimated to increase odds of colorectal (OR: 1.27, 95% CI: 1.03, 1.57), colon (OR: 1.32, 95% CI: 1.05, 1.67), and proximal colon (OR: 1.57, 95% CI: 1.21, 2.05).

CONCLUSIONS

Our findings suggest that the positive association between early life body size and colorectal cancer risk is likely due to large body size retainment into adulthood.

Association of childhood and adolescence obesity with incidence and mortality of adulthood cancers. A systematic review and meta-analysis

BACKGROUND

Prevalence and subsequent conditions of childhood and adolescent obesity are increasing. It has been seen that obesity in youth is associated with adulthood cancer. This systematic review and meta-analysis aimed to determine the pooled association of childhood obesity with cancers in adulthood.

METHODS

In this systematic review, international electronic databases such as Scopus, PubMed, Web of Science, and EMBASE were searched using relevant keywords until February 2022. All Cohort studies assessing the association of childhood and adolescent obesity (under 18 years old) with the incidence and mortality of all types of cancers were included. Two independent reviewers screened and carried out the quality assessment of included studies. Between-studies heterogeneity was assessed using the I squared and Cochran's Q tests. Random/fixed-effect meta-analyses were used to pool the appropriate effect sizes (Hazard ratios (HR)).

RESULTS

Overall, 46 studies were found to be relevant and were included in this study. Based on the random-effects model meta-analysis, childhood obesity increased the hazard of cancer incidence and mortality in adulthood by 33% (HR: 1.33, 95%CI (1.25, 1.41)) and by 28% (HR: 1.28, 95%CI (1.13, 1.42)), respectively. In the subgroups meta-analysis, the HR of childhood obesity and adulthood cancer incidence mortality in women was higher than in men (HR=1.39, 95%CI (1.25, 1.53) vs HR= 1.20, 95%CI (1.07, 1.32)) and (HR= 1.40, 95%CI (1.10, 1.69) vs HR=1.20, 95%CI (1.04, 1.36)) respectively.

CONCLUSION

This study found that obesity in childhood and adolescence is associated with a significant increase in the incidence and mortality of cancers in adulthood. Prevention of childhood obesity, in addition to its short-term beneficial effects, can reduce the burden of cancer in adulthood. The data sets of this study are present in the Tables of the current manuscript. Moreover this study was registered online in PROSPERO (registration code: CRD42022331958).

SYSTEMIC REVIEW REGISTRATION

https://www.crd.york.ac.uk/Prospero/, identifier CRD42022331958.

Risk factors for early-onset colorectal cancer: systematic review and meta-analysis

Background

The incidence of early-onset colorectal cancer (EOCRC), which means colorectal cancer diagnosed in patients under 50 years, has been increasing around the world. However, the etiology remains unclear. This study aims to identify risk factors for EOCRC.

Methods

This systematic review was conducted in PubMed, Embase, Scopus, and Cochrane Library databases from inception to November 25, 2022. We examined risk factors for EOCRC, including demographic factors, chronic conditions, and lifestyle behaviors or environmental factors. Random-effects/fixed-effects meta-analysis was adopted to combine effect estimates from published data. Study quality was evaluated with the Newcastle-Ottawa Scale (NOS). Statistical analysis was performed Revman5.3. Studies not suitable for the meta-analysis were analyzed by a systematic review.

Results

A total of 36 studies were identified for this review, and 30 studies were included in the meta-analysis. Significant risk factors for EOCRC included male (OR=1.20; 95% CI, 1.08-1.33), Caucasian (OR=1.44; 95% CI, 1.15-1.80), a family history of CRC (OR=5.90; 95% CI, 3.67-9.48), inflammatory bowel disease (OR=4.43; 95% CI, 4.05-4.84), obesity (OR=1.52; 95%CI, 1.20-1.91), overweight (OR=1.18; 95% CI, 1.12-1.25), triglycerides (OR=1.12; 95% CI, 1, 08-1.18), hypertension (OR=1.16; 95% CI, 1.12-1.21), metabolic syndrome (OR=1.29; 95% CI, 1.15-1.45), smoking (OR=1.44; 95% CI, 1.10-1.88), alcohol consumption (OR=1.41; 95% CI, 1.22-1.62), a sedentary lifestyle (OR=1.24; 95% CI, 1.05-1.46), red meat (OR=1.10; 95% CI, 1.04-1.16), processed meat (OR=1.53; 95% CI, 1.13-2.06), Western dietary patterns (OR=1.43; 95% CI, 1.18-1.73) and sugar-sweetened beverages (OR=1.55; 95% CI, 1.23-1.95). However, no statistical differences were found for hyperlipidemia and hyperglycemia. Vitamin D may be a protective factor (OR=0.72; 95% CI, 0.56-0.92). There was considerable heterogeneity among studies (I²>60%).

Conclusions

The study provides an overview of the etiology and risk factors of EOCRC. Current evidence can provide baseline data for risk prediction models specific to EOCRC and risk-tailored screening strategies.

Is early-onset cancer an emerging global epidemic? Current evidence and future implications

Over the past several decades, the incidence of early-onset cancers, often defined as cancers diagnosed in adults <50 years of age, in the breast, colorectum, endometrium, oesophagus, extrahepatic bile duct, gallbladder, head and neck, kidney, liver, bone marrow, pancreas, prostate, stomach and thyroid has increased in multiple countries. Increased use of screening programmes has contributed to this phenomenon to a certain extent, although a genuine increase in the incidence of early-onset forms of several cancer types also seems to have emerged. Evidence suggests an aetiological role of risk factor exposures in early life and young adulthood. Since the mid-20th century, substantial multigenerational changes in the exposome have occurred (including changes in diet, lifestyle, obesity, environment and the microbiome, all of which might interact with genomic and/or genetic susceptibilities). However, the effects of individual exposures remain largely unknown. To study early-life exposures and their implications for multiple cancer types will require prospective cohort studies with dedicated biobanking and data collection technologies. Raising awareness among both the public and health-care professionals will also be critical. In this Review, we describe changes in the incidence of early-onset cancers globally and suggest measures that are likely to reduce the burden of cancers and other chronic non-communicable diseases.

Risk Factors for Early-Onset Colorectal Cancer: A Systematic Review and Meta-analysis

BACKGROUND & AIMS

Despite the widespread increase in the incidence of early-onset colorectal cancer (EoCRC), the reasons for this increase remain unclear. The objective of this study was to determine risk factors for the development of EoCRC.

METHODS

We conducted a systematic literature review and meta-analysis of studies examining non-genetic risk factors for EoCRC, including demographic factors, comorbidities, and lifestyle factors. Random effects meta-analyses were conducted for risk factors that were examined in at least three studies. Heterogeneity was investigated using the Q-test and I² statistic.

RESULTS

From 3304 initial citations, 20 studies were included in this review. Significant risk factors for EoCRC included CRC history in a first-degree relative (RR 4.21, 95% CI 2.61-6.79), hyperlipidemia (RR 1.62, 95% CI 1.22-2.13), obesity (RR 1.54, 95% CI 1.01-2.35), and alcohol consumption (high vs. non-drinkers) (RR 1.71, 95% CI 1.62-1.80). While smoking was suggestive as a risk factor, the association was not statistically significant (RR 1.35, 95% CI 0.81-2.25). With the exception of alcohol consumption, there was considerable heterogeneity among studies (I² > 60%). Other potential risk factors included hypertension, metabolic syndrome, ulcerative colitis, chronic kidney disease, dietary factors, sedentary behaviour, and occupational exposure to organic dusts, but these were only examined in one or two studies.

CONCLUSIONS

The results of this study advance the understanding of the etiology of EoCRC. High-quality studies conducted on generalizable populations and that comprehensively examine risk factors for EoCRC are required to inform primary and secondary prevention strategies.

Associations of Body Mass Index at Different Ages With Early-Onset Colorectal Cancer

BACKGROUND & AIMS

Incidence of colorectal cancer (CRC) in younger adults is increasing in many countries. Given the established association of body mass index (BMI) with CRC risk and the increasing obesity prevalence among younger generations, we aimed to evaluate the association of BMI at different ages during early adulthood with early-onset CRC.

METHODS

Among 6602 patients with CRC and 7950 matched controls who were recruited in 2003-2020 in the Darmkrebs: Chancen der Verhütung durch Screening study, a population-based case-control study from Germany, 747 patients and 621 controls were younger than 55 years and included in this analysis. Self-reported height and weight at ages 20 years and 30 years and at approximately 10 years before diagnosis or interview were recorded in personal interviews. Associations of BMI with early-onset CRC were estimated using multiple logistic regression.

RESULTS

Compared with participants with BMI <25 kg/m², those with BMI ≥30 kg/m² (obesity) at ages 20 years and 30 years and approximately 10 years before diagnosis or interview had 2.56- (95% confidence interval, 1.20-5.44), 2.06- (confidence interval, 1.25-3.40), and 1.88- (95% confidence interval, 1.30-2.73) fold risk of early-onset CRC. The association of BMI with early-onset CRC risk was particularly pronounced among, and essentially restricted to, the majority of participants with no previous colonoscopy.

CONCLUSIONS

Obesity at early adulthood is strongly associated with increased risk of early-onset CRC. German Clinical Trials Register ID: DRKS00011793.

Obesity during childhood is associated with higher cancer mortality rate during adulthood: the i3C Consortium

BACKGROUND

In high-income countries, cancer is the leading cause of death among middle-aged adults. Prospective data on the effects of childhood risk exposures on subsequent cancer mortality are scarce.

METHODS

We examined whether childhood body mass index (BMI), blood pressure, glucose and lipid levels were associated with adult cancer mortality, using data from 21,012 children enrolled aged 3-19 years in seven prospective cohort studies from the U.S., Australia, and Finland that have followed participants from childhood into adulthood. Cancer mortality (cancer as a primary or secondary cause of death) was captured using registries.

RESULTS

354 cancer deaths occurred over the follow-up. In age-, sex, and cohort-adjusted analyses, childhood BMI (Hazard ratio [HR], 1.13; 95% confidence interval [CI] 1.03-1.24 per 1-SD increase) and childhood glucose (HR 1.22; 95%CI 1.01-1.47 per 1-SD increase), were associated with subsequent cancer mortality. In a multivariable analysis adjusted for age, sex, cohort, and childhood measures of fasting glucose, total cholesterol, triglycerides, and systolic blood pressure, childhood BMI remained as an independent predictor of subsequent cancer mortality (HR, 1.24; 95%CI, 1.03-1.49). The association of childhood BMI and subsequent cancer mortality persisted after adjustment for adulthood BMI (HR for childhood BMI, 1.35; 95%CI 1.12-1.63).

CONCLUSIONS

Higher childhood BMI was independently associated with increased overall cancer mortality.

Association of Body Mass Index With Risk of Early-Onset Colorectal Cancer: Systematic Review and Meta-Analysis

INTRODUCTION

Incidence of colorectal cancer (CRC) in young adults has been increasing in recent decades in many countries for still widely unclear reasons. Suspected candidates include increasing prevalence of overweight and obesity, but specific evidence on their role for early-onset CRC (EOCRC) is sparse. We conducted a systematic review and meta-analysis to summarize available evidence on the association of body mass index (BMI) with EOCRC.

METHODS

We systematically searched PubMed, EMBASE, and Web of Science up to February 2021 for studies that evaluated the association of BMI (before diagnosis but not near diagnosis) with CRC risk and reported specific results for EOCRC. Results from studies with similar BMI groupings were summarized in meta-analyses using random-effects models.

RESULTS

Twelve studies were eligible and included. Results of 6 studies were pooled in meta-analyses, which yielded a higher risk of EOCRC for overweight and obesity (BMI ≥25 kg/m2) compared with normal weight (odds ratio [OR] 1.42, 95% confidence interval [CI] 1.19-1.68). An increasing risk with increasing BMI was observed, with much higher risk for obesity (OR 1.88, 95% CI 1.40-2.54) than for overweight (OR 1.32, 95% CI 1.19-1.47).

DISCUSSION

Obesity is a strong risk factor for EOCRC, and its increasing prevalence in younger generations is likely to substantially contribute to the increase in EOCRC. Efforts to limit the obesity epidemic in adolescents and younger adults may be crucial for reducing CRC incidence in future generations of adults.

Excess Body Weight and Gastrointestinal Cancer Risk

Background

Excess body weight (EBW), defined as a body mass index (BMI) ≥25 kg/m², has become the second most important as well as a potentially modifiable risk factor for cancer in many industrialized countries. The more excess weight people have, the higher the risk of certain cancers. Over the past several decades, EBW has been increasing globally not only among adults, but also among children and adolescents.

Summary

EBW is causally associated with colorectal, esophageal (adenocarcinoma), gastric (cardia), pancreatic, biliary and hepatocellular cancer. EBW when combined with tobacco smoking, risky alcohol use, or diabetes can act synergistically to cause gastrointestinal cancer. In recent years, more and more young adults (20-40 years old) were diagnosed with EBW-associated neoplasms. People with EBW should be encouraged to join cancer screening programs.

Key Messages

Keeping a healthy weight is a major public health concern and reduces the risk of cancer.

Rectal Cancer in Adolescent and Young Adult Patients: Pattern of Clinical Presentation and Case-Matched Comparison of Outcomes

BACKGROUND

Rectal cancer in adolescents and young adults (age ≤39) is increasing. Early diagnosis is a challenge in this subset of patients.

OBJECTIVE

This study aims to analyze the presentation pattern and outcomes of sporadic rectal cancer in adolescents and young adults.

DESIGN

This is a retrospective study.

SETTING

This study was conducted at 3 European tertiary centers.

PATIENTS

Data on adolescents and young adults operated on for sporadic rectal cancer (January 2008 through October 2019) were analyzed. To compare outcomes, adolescents and young adults were matched to a group of patients aged ≥40 operated on during the same period.

MAIN OUTCOME MEASURES

The primary outcomes measured were clinical presentation and long-term outcomes.

RESULTS

Sporadic rectal cancers occurred in 101 adolescents and young adults (2.4%; mean age, 33.5; range, 18-39); 51.5% were male, and a smoking habit was reported by 17.8% of patients. The rate of a family history for colorectal cancer was 25.7%, and of these patients, 24.7% were obese. Diagnosis based on symptoms was reported in 92.1% patients, and the mean time from first symptoms to diagnosis was 13.7 months. The most common symptom at diagnosis was rectal bleeding (68.8%), and 12% and 34% of the adolescents and young adults presented with locally advanced or metastatic disease at diagnosis. Consequently, 68.3% and 62.4% adolescents and young adults received neoadjuvant and adjuvant treatments. The rate of complete pathological response was 24.1%; whereas 38.6% patients had stage IV disease, and 93.1% were microsatellite stable. At a mean follow-up of 5 years, no difference in cancer-specific survival, but a lower disease-free survival was reported in adolescents and young adults (p < 0.0001) vs the matched group. Adolescents and young adults with stages I to II disease had shorter cancer-specific survival and disease-free survival (p = 0.006; p < 0.0001); with stage III disease, they had a shorter disease-free survival (p = 0.01).

LIMITATIONS

This study was limited by its observational, retrospective design.

CONCLUSIONS

The significantly delayed diagnosis in adolescents and young adults may have contributed to the advanced disease at presentation and lower disease-free survival, even at earlier stages, suggesting a higher metastatic potential than in older patients. See Video Abstract at http://links.lww.com/DCR/B537.

CNCER DE RECTO EN PACIENTES ADOLESCENTES Y ADULTOS JVENES CUADRO DE PRESENTACIN CLNICA Y COMPARACIN DE DESENLACES POR CASOS EMPAREJADOS

ANTECEDENTES:El cáncer de recto en adolescentes y adultos jóvenes (edad ≤ 39) está aumentando. El diagnóstico temprano es un desafío en este subgrupo de pacientes.OBJETIVO:Analizar el cuadro de presentación y los desenlaces en adolescentes y adultos jóvenes con cáncer de recto esporádico.DISEÑO:Estudio retrospectivo.ÁMBITO:Tres centros europeos de tercer nivel.PACIENTES:Se analizaron los datos de adolescentes y adultos jóvenes operados de cáncer de recto esporádico (enero de 2008 - octubre de 2019). Para comparar los desenlaces se emparejó a adolescentes y adultos jóvenes con un grupo de pacientes mayores de 40 años operados en el mismo período de tiempo.PRINCIPALES VARIABLES ANALIZADAS:Cuadro clínico, resultados a largo plazo.RESULTADOS:Los cánceres de recto esporádicos en adolescentes y adultos jóvenes fueron 101 (2,4%, edad media: 33,5, rango 18-39). El 51,5% eran hombres, el 17,8% de los pacientes fumaba. El 25,7% tentía antecedentes familiares de cáncer colorrectal. El 24,7% eran obesos. El diagnóstico con base en los síntomas se informó en el 92,1% de los pacientes, el tiempo promedio desde los primeros síntomas hasta el diagnóstico fue de 13,7 meses. El síntoma más común en el momento del diagnóstico fue el sangrado rectal (68,8%). 12% y 34% de adolescentes y adultos jóvenes presentaron enfermedad localmente avanzada o metastásica en el momento del diagnóstico. Por lo tanto, el 68,3% y el 62,4% de adolescentes y adultos jóvenes recibieron neoadyuvancia y adyuvancia. La tasa de respuesta patológica completa fue del 24,1%; mientras que el 38,6% estaban en estadio IV. El 93,1% eran microsatelite estable. Con una media de seguimiento de 5 años, no se observaron diferencias en la sobrevida específica del cáncer, pero se informó una menor sobrevida libre de enfermedad en adolescentes y adultos jóvenes (p <0,0001) frente al grupo emparejado. Los adolescentes y adultos jóvenes en estadios I-II tuvieron una sobrevida específica por cáncer y una sobrevida libre de enfermedad más corta (p = 0,006; p <0,0001); el estadio III tuvo una sobrevida libre de enfermedad más baja (p = 0,01).LIMITACIONES:Diseño observacional y retrospectivo.CONCLUSIONES:El diagnóstico notablemente demorado en adolescentes y adultos jóvenes puede contribuir a la presentación de una enfermedad avanzada y a una menor sobrevida libre de enfermedad, incluso en estadios más tempranas, lo cual implica un mayor potencial metastásico en comparación con pacientes mayores. Consulte Video Resumen en http://links.lww.com/DCR/B537.

Adolescent and Childhood Obesity and Excess Morbidity and Mortality in Young Adulthood-a Systematic Review

PURPOSE OF REVIEW

Rates of childhood obesity have been soaring in recent decades. The association between obesity in adulthood and excess morbidity and mortality has been readily established, whereas the association of childhood and adolescent obesity has not. The purpose of this review is to summarize existing data regarding the association of the presence of obesity in childhood/adolescence and early-onset adverse outcomes in adulthood, with specific focus on young adults under the age of 45 years.

RECENT FINDINGS

Diabetes, cancer, and cardiometabolic outcomes in midlife are closely linked to childhood and adolescent obesity. Childhood and adolescent obesity confer major risks of excess and premature morbidity and mortality, which may be evident before age 30 years in both sexes. The scientific literature is mixed regarding the independent risk of illness, which may be attributed to childhood BMI regardless of adult BMI, and additional data is required to establish causality between the two. Nonetheless, the increasing prevalence of childhood and adolescent obesity may impose an increase of disease burden in midlife, emphasizing the need for effective interventions to be implemented at a young age.

Young-Onset Carcinogenesis - The Potential Impact of Perinatal and Early Life Metabolic Influences on the Epigenome

The last decade has witnessed a significant rise in cancers in young adults. This spectrum of solid organ cancers occurring in individuals under the age of 40 years (some reports extending the age-group to <50 years) in whom aetiology of cancer cannot be traced back to pre-existing familial cancer syndromes, is referred to as termed young-, or early- onset cancers. The underlying causes for young-onset carcinogenesis have remained speculative. We recently proposed a hypothesis to explain the causation of this entity. We propose that the risk for young-onset cancer begins in the perinatal period as a result of the exposure of the foetus to stressors, including maternal malnutrition, smoking or alcohol, with the consequent epigenomic events triggered to help the foetus cope/adapt. Exposure to the same stressors, early in the life of that individual, facilitates a re-activation of these ‘responses designed to be protective’ but ultimately resulting in a loss of regulation at a metabolic and/or genetic level culminating in the evolution of the neoplastic process. In this manuscript, we will provide a rationale for this hypothesis and present evidence to further support it by clarifying the pathways involved, including elucidating a role for Acetyl-CoA and its effect on the epigenome. We present strategies and experimental models that can be used to test the hypothesis. We believe that a concerted effort by experts in different, but complementary fields, such as epidemiology, genetics, and epigenetics united towards the common goal of deciphering the underlying cause for young-onset cancers is the urgent need. Such efforts might serve to prove, or disprove, the presented hypothesis. However, the more important aim is to develop strategies to reverse the disturbing trend of the rise in young-onset cancers.

A comparison of methods in estimating population attributable risk for colorectal cancer in the United States

Population attributable risk (PAR) is becoming more widely used for quantifying preventability of cancer. However, its estimations have had a wide range, leading to questions about the true preventability. Our study aimed to compare the two PAR estimation methods (ie, literature-based method and low-risk method) for colorectal cancer (CRC) in the US population based on the same set of modifiable risk factors: physical activity, body mass index, alcoholic drinks, red meat, processed meat, dietary fiber, dietary calcium and cigarette smoking. For the literature-based method, 65% and 53%, and for the low-risk method, 62% and 49% of CRC cases for males and females, respectively, were attributable to the eight dietary and lifestyle risk factors. Additional sensitivity analyses were conducted with respect to the different choices of risk factors, relative risks (RRs) and exposure prevalence estimates used in the literature-based method. The PARs including only the "convincing" factors and excluding "probable" factors defined by the WCRF/AICR were 50% for males and 34% for females. Using RRs derived from different studies changed the PARs considerably (57%-74% for males and 37%-60% for females). Our study assessed the robustness of PAR calculations through a direct comparison between the two methods using different assumptions and data and generally found high concordance. From the additional analyses, we found that the choice of risk factors and RRs could substantially influence the PAR estimates. Given the findings, future studies reporting PAR should consider presenting a range of PAR estimates based on choices of risk factors and RRs.

Coding Variants are Relevant to the Expression of Obesity-Related Genes for Pediatric Adiposity

OBJECTIVE

Heredity has a remarkable effect on obesity in an obesogenic environment. Despite the numerous genetic variants that contribute to obesity-related traits, none has been identified in Chinese children. This study aimed to identify novel variants associated with childhood obesity in China.

METHODS

Promising single-nucleotide variants were obtained using whole-exome sequencing from 76 children who had obesity and 74 children with normal weight, and their associations with obesity-related traits in an additional 6,334-child cohort were investigated. The effects of the genome-wide significant (P < 5E-8) variants on the expression of the implicated genes in blood and adipose tissue were then depicted using transcriptome sequencing.

RESULTS

Two coding variants associated with obesity with genome-wide significance were identified: rs1059491 (P = 2.57E-28) in SULT1A2 and rs189326455 (P = 8.98E-12) in MAP3K21. In addition, rs1059491 was also significantly associated with several obesity traits. Transcriptome sequencing demonstrated that rs1059491 and rs189326455 were expression quantitative trait loci relevant to the expression levels of several obesity-related genes, such as SULT1A2, ATXN2L, TUFM, and MAP3K21.

CONCLUSIONS

This work identified two coding variants that were significantly associated with pediatric adiposity and were expression quantitative trait loci for obesity-related genes. This study provides new insights into the pathophysiology of Chinese childhood obesity.

Excessive Body Fat at a Young Age Increases the Risk of Colorectal Cancer: A Systematic Review and Meta-Analysis

Overweight and obesity was considered as a risk factor for colorectal cancer (CRC), and CRC development may be due to exposure during one's youth. Metabolic syndrome and insulin resistance seem to play an important role in the underlying mechanisms. Even though several studies indicated the association between BMI at young age and CRC risks, an identified founding is still lacked. Therefore, we conducted a meta-analysis and a dose-response analysis to quantify the association between BMI at young age and CRC risks with relative accuracy. We searched the PubMed, Embase, Medline and Cochrane Library databases for articles published before Sep. 15, 2019. Fifteen articles with 2 520 091 participants were included. Risk for CRC was estimated using relative risks (RR) and 95% confidence intervals (CIs). Compared with individuals with normal weight, overweight and obese young adults had a significantly higher risk of CRC (relative risks (RR):18%, 95% CI:1.08, 1.28； RR:32%, 95% CI: 1.11, 1.56, respectively). However, this correlation may not exist for obese women (RR: 1.22, 95% CI: 0.99, 1.51); Overweight may not a risk factor for rectal cancer (RC) (RR: 1.12, 95% CI: 0.97, 1.29). In the dose-response analysis, we observed a linear relationship between BMI at a young age and CRC risk, with each 1 kg/m² increment associated with a 2% increased risk. Higher BMI at a young age was positively associated with CRC risk, which indicates that weight control since a young age was needed.

Early-onset colorectal cancer: initial clues and current views

Over the past several decades, the incidence of early-onset colorectal cancer (EOCRC; in patients <50 years old) has increased at an alarming rate. Although robust and scientifically rigorous epidemiological studies have sifted out environmental elements linked to EOCRC, our knowledge of the causes and mechanisms of this disease is far from complete. Here, we highlight potential risk factors and putative mechanisms that drive EOCRC and suggest likely areas for fruitful research. In addition, we identify inconsistencies in the evidence implicating a strong effect of increased adiposity and suggest that certain behaviours (such as diet and stress) might place nonobese and otherwise healthy people at risk of this disease. Key risk factors are reviewed, including the global westernization of diets (usually involving a high intake of red and processed meats, high-fructose corn syrup and unhealthy cooking methods), stress, antibiotics, synthetic food dyes, monosodium glutamate, titanium dioxide, and physical inactivity and/or sedentary behaviour. The gut microbiota is probably at the crossroads of these risk factors and EOCRC. The time course of the disease and the fact that relevant exposures probably occur in childhood raise important methodological issues that are also discussed.

Which obesity-associated parameters can better reflect the risk of the occurrence of the anastomotic leakage?

Purpose: We investigated which obesity-associated parameters can better predict the risk of anastomotic leakage (AL) in rectal cancer patients that underwent anterior resection of the rectum.Method: Patients (n = 589) who underwent anterior resection of the rectum with a primary anastomosis were included in this study, including 44 patients with AL and 545 without AL. Univariate analysis was used to compare demographic characteristics and to select risk factors that were used in one-to-one propensity score matching (PSM). Obesity-associated parameters, including preoperative body mass index (BMI), visceral fat area (VFA), subcutaneous fat area (SFA), total fat area (TFA), VFA/TFA ratio, serum cholesterol, and triglycerides, were compared between the two groups after PSM.Results: Sex, neoadjuvant chemotherapy, operation time, and anastomosis level from the anal verge were risk factors for AL (p < .05). After the PSM, BMI, VFA, SFA, TFA, VFA/TFA, and serum cholesterol showed no significant difference between the two group (p > .05). However, the level of serum triglycerides was an independent risk factor for AL (p = .024, odds ratio = 2.95).Conclusions: Serum triglycerides have potential as a predictive indicator for AL, which may improve the treatment and outcomes of patients with AL.

Adolescent characteristics and incidence of pre-malignant disease and invasive tumors of the cervix

INTRODUCTION

Pre-malignant cervical disease and invasive cervical cancer present a significant global health burden with respect to morbidity and mortality, mostly in low- and middle-income countries. Human papillomavirus (HPV) infection typically manifests for the first time in adolescence. We aimed to identify adolescent sociodemographic and anthropometric characteristics associated with subsequent risk for pre-malignant cervical disease and cervical cancer, in a country that offers free screening and HPV vaccines.

METHODS

This historical cohort study included 969 123 Israeli women examined and anthropometrically measured at age 17 years between January 1967 and December 2011. Data on pre-malignant disease and invasive cervical tumors were obtained from the national cancer registry by linkage. We excluded non-Jewish minorities (a total of 25 472 women) and orthodox/ultraorthodox Jewish women since these populations are not required by law to serve in the military, as well as women with a pre-examination diagnosis of cancer. Cox proportional hazards regression models were applied per each lesion type, adjusted for origin, measured body mass index, height, education, dwelling type, birth year, and age at examination.

RESULTS

In total, 5094 and 859 incident pre-malignant cervical disease and cervical cancer cases, respectively, were diagnosed during a median follow-up of 17.6 years. Risk for both lesions was origin-dependent, with higher incidence in women of North-African origin (HR (pre-malignant cervical disease) 1.22, 95% CI 1.04 to 1.42; HR (cervical cancer) 1.87, 95% CI 1.30 to 2.69) compared with European origin. Height, lower education, and later birth year were associated with higher pre-malignant cervical disease and cervical cancer risk also. Adolescent overweight (HR 0.81, 95% CI 0.74 to 0.90) and obesity (HR 0.56, 95% CI 0.43 to 0.71) status were associated with reduced pre-malignant cervical disease but not cervical cancer incidence, as did urban (vs rural) residence.

DISCUSSION

Ethnic background, tall stature, and education were associated with pre-malignant cervical disease and cervical cancer incidence, while adolescent overweight and obesity were inversely associated with only pre-malignant cervical disease. Despite free screening and HPV vaccines, these findings suggest that there is still a need for appropriate safe sex and screening education in adolescence.

Proportion of Cancer Cases Attributable to Excess Body Weight by US State, 2011-2015

Importance

Excess body weight (EBW) is an established cause of cancer. Despite variations in the prevalence of EBW among US states, there is little information on the EBW-related cancer burden by state; this information would be useful for setting priorities for cancer-control initiatives.

Objective

To calculate the population attributable fraction (PAF) of incident cancer cases attributable to EBW among adults 30 years or older in 2011 to 2015 in all 50 states and the District of Columbia.

Design, Setting, and Participants

State-level, self-reported body mass index (BMI [calculated as weight in kilograms divided by height in meters squared]) data from the Behavioral Risk Factor Surveillance System were adjusted by sex, age, race/ethnicity, and education using objectively measured BMI values from the National Health and Nutrition Examination Survey. Age- and sex-specific cancer incidence data by state were obtained from the US Cancer Statistics database. All analyses were performed between February 15, 2018, and July 17, 2018.

Main Outcomes and Measures

Sex-, age-, and state-specific adjusted prevalence estimates for 4 high BMI categories and corresponding relative risks from large-scale pooled analyses or meta-analyses were used to compute the PAFs for each US state for esophageal adenocarcinoma, multiple myeloma, and cancers of the gastric cardia, colorectum, liver, gallbladder, pancreas, female breast, corpus uteri, ovary, kidney and renal pelvis, and thyroid.

Results

Each year, an estimated 37 670 cancer cases in men (4.7% of all cancer cases excluding nonmelanoma skin cancers) and 74 690 cancer cases in women (9.6%) 30 years or older in the United States were attributable to EBW from 2011 to 2015. In both men and women, there was at least a 1.5-fold difference in the proportions of cancers attributable to EBW between states with the highest and lowest PAFs. Among men, the PAF ranged from 3.9% (95% CI, 3.6%-4.3%) in Montana to 6.0% (95% CI, 5.6%-6.4%) in Texas. The PAF for women was approximately twice as high as for men, ranging from 7.1% (95% CI, 6.7%-7.6%) in Hawaii to 11.4% (95% CI, 10.7%-12.2%) in the District of Columbia. The largest PAFs were found mostly in southern and midwestern states, as well as Alaska and the District of Columbia.

Conclusions and Relevance

The proportion of cancers attributable to EBW varies among states, but EBW accounts for at least 1 in 17 of all incident cancers in each state. Broad implementation of known community- and individual-level interventions is needed to reduce access to and marketing of unhealthy foods (eg, through a tax on sugary drinks) and to promote and increase access to healthy foods and physical activity, as well as preventive care.

Obesity, diabetes and the risk of colorectal adenoma and cancer

BACKGROUND

Colorectal cancer (CRC) is the fourth most commonly diagnosed gastrointestinal (GI) malignancy and the third leading cause of cancer-related death worldwide. In the current case-control study, an association between diagnosis of CRC, obesity and diabetes was investigated.

METHODS

Demographic characteristics, colonoscopy reports, history of drug, smoking, and medical history were collected from patients referred to a colonoscopy unit. The location, size and number of the polyps were recorded during the colonoscopy. Statistically, t-test was conducted for mean comparison for the groups. Pearson's chi-squared test (χ2) was applied to categorize variables. Five classification methods based on the important clinicopathological characteristics such as age, BMI, diabetes, family history of colon cancer was performed to predict the results of colonoscopy.

RESULTS

Overall, 693 patients participated in this study. In the present study, 115 and 515 patients were evaluated for adenoma/adenocarcinoma and normal colonoscopy, respectively. The mean age of patients positive for adenoma or adenocarcinoma were significantly higher than the negative groups (p value < 0.001). Incidence of overweight and/or obesity (BMI > 25 kg/m2) were significantly higher in adenoma positive patients as compared to controls (49.9 and 0.9% respectively, p value = 0.04). The results also demonstrated a significant association between suffering from diabetes and having colon adenoma (OR = 1.831, 95%CI = 1.058-3.169, p value = 0.023). The experimental results of 5 classification methods on higher risk factors between colon adenoma and normal colonoscopy data were more than 82% and less than 0.42 for the percentage of classification accuracy and root mean squared error, respectively.

CONCLUSIONS

In the current study, the occurrence of obesity measured based on BMI and diabetes in the adenoma positive patient group was significantly higher than the control group although there was no notable association between obesity, diabetes and adenocarcinoma.

Rectal cancer in the young: analysis of contributing factors and surgical outcomes

Background

Rectal cancer (RC) among young patients (≤50 years) is on the rise. The factors associated with development of RC are established however; factors leading to early RC remain unclear. The aim of this study was to assess factors associated with RC among young patients.

Methods

National estimates for patients with RC were abstracted from the National Inpatient Sample (NIS) database [2010-2012]. Patients were divided into two groups: young (≤50 years) and old (>50 years). Demographic, comorbidities, procedures performed, and hospital outcomes were collected. Regression analysis was performed to compare both groups.

Results

A total of 68,699 patients with RC were included. Incidence of RC among young patients increased significantly over the study period (2.4% vs. 3.4%; P=0.04). Majority of young patients with RC were white females. Bleeding was the most common presentation among young patients (P=0.03). Younger patients were more likely to have a family history of RC (P=0.01) and were more likely to undergo elective surgery (P=0.04) and laparoscopic surgery (P=0.02) compared to the older patients. Younger patients with RC were also more likely to use alcohol (P=0.03), be obese (P=0.02) compared to elder patients. There was no difference in the other co-morbidities between the two groups. After controlling for all factors in a regression model, younger patients had a lower complication rate (P=0.01), hospital LOS (P=0.02), and mortality rate (P=0.04).

Conclusions

RC in younger patients appears as a different disease with different outcomes. There appears to be multifactorial and environmental factors contributing to this trend. Race and gender also play a role in the incidence of RC in the young. Identifying these risk factors will lead to a more robust intervention plan to help improve care among younger patients with RC.

Behavioral and Physiological Health-Related Risk Factors in College Students

The purpose of this study was to assess the behavioral and physiological health-related risk factors in college students. A cross-sectional study was conducted in 1620 college students (21.3 ± 1.7 years, 897 males, and 723 females). Physical activity (PA), sitting time, body composition, cardiorespiratory fitness (CRF), muscular endurance (ME), and blood test were assessed. In the total sample, 15.2% were not meeting PA guidelines, 33% were sedentary, 13.3% were obese, 10.7% had low CRF, 36.8% had poor ME, 33.7% had dyslipidemia and 5.9% presented with prediabetes. Obesity and poor CRF were more prevalent in male students, whereas inactivity was more prevalent in female students. Individuals with poor CRF were more likely to be obese (odds ratio = 5.2, 95% CI = 3.5-7.8, P = .007 for male students, and 9.4, 95% CI = 1.5-57.8, P = .021 for female students). Sitting time positively correlated with fat percentage (fat%) and inversely with lean body mass (LBM) in male students, whereas ME inversely correlated with fat% and positively with LBM in female students. Although most students were active, significant prevalence of health-related risk factors were observed. Sedentary behavior and poor fitness were associated with a compromised body composition in both sexes. Improving fitness and reducing sedentary behavior in college students could be a public health strategy for health promotion and chronic diseases prevention.

Estrogen Receptor Beta (ERβ) Mediated-CyclinD1 Degradation via Autophagy Plays an Anti-Proliferation Role in Colon Cells

Dysfunction of autophagic degradation machinery causes tumorigenesis, including colorectal cancer (CRC). Overexpression of CyclinD1 in CRC has been reported. Recent evidence also suggests that ERβ deficiency is related to the pathogenesis of CRC. Very little is known, however, about the detailed molecular mechanisms underlying the relationship among ERβ, autophagy, and CyclinD1 in CRC. Here, results showed that ERβ played an anti-proliferation role in HCT116 through impairing cell cycle but not apoptosis. Additionally, CyclinD1 accumulation was increased in response to chloroquine (CQ) or in MEF Atg7 knockout cells. Further, ERβ could inhibit the mammalian target of rapamycin (mTOR) or activate Bcl-2/adenovirus E1B 19-kDa-interacting protein 3 (BNIP3) to promote autophagy in HCT116. In summary, these results indicate that ERβ-mediated CyclinD1 degradation can inhibit colon cancer cell growth via autophagy.

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.

The effect of increased body mass index values on surgical outcomes after radical resection for low rectal cancer

PURPOSES

This study aimed to explore the effect of increased body mass index (BMI) values (overweight: BMI ≥ 25-30 kg/m²; obese: BMI ≥ 30 kg/m²) on surgical outcomes after radical resection for low rectal cancer (LRC).

METHODS

Patients with LRC who underwent radical surgery from January 2009 to December 2013 were included. The patients were divided into three groups according to their BMI values (control group: BMI < 25 kg/m²; overweight group: BMI 25 to < 30 kg/m²; obese group: BMI ≥ 30 kg/m²). The patients' clinicopathological characteristics and survival data were collected and analyzed.

RESULTS

A total of 792 patients were enrolled in this study finally (control, n = 624; overweight, n = 147; obese, n = 21). The baseline characteristics of the three groups were similar. We found that an increased BMI was associated with a longer operative time (P < 0.001) and length of postoperative hospital stay (P = 0.032). Patients with increased BMI values had a significantly higher incidence of postoperative complications, including pulmonary infection (P = 0.008), anastomotic leakage (P = 0.029), allergy (P = 0.017) and incisional hernia (P = 0.045). The limited data showed that the pathological outcomes of the three groups did not differ to a statistically significant extent. A multivariate analysis showed that increased BMI was not associated with poorer OS or DFS.

CONCLUSION

In LRC resection, an increased BMI was associated with a longer operative time, postoperative hospital stay, and an increased number of postoperative complications. However, it did not contribute to poorer pathological or survival outcomes.

Early-life obesity and adulthood colorectal cancer risk: a meta-analysis

Objective

This meta-analysis examines the relationship between early-life obesity and risk of colorectal cancer (CRC) in adulthood.

Methods

A systematic search of Google Scholar, PubMed, and reference data was conducted. Fifteen relevant studies were identified and meta-analyzed, for men and women separately. A random-effects model was used to compare the multivariable-adjusted relative risks (RR) of overall and subsite-specific CRC to the highest versus lowest categories of body mass index (BMI) in early life. Meta-regression was performed on factors that may have contributed to between-study heterogeneity.

Results

High early-life BMI was associated with a 39% increased risk of CRC in adult men (RR = 1.39, 95%CI = 1.20 – 1.62, P < 0.0001) and a 19% increased risk of CRC in adult women (RR = 1.19, 95%CI = 1.06 – 1.35, P = 0.004). No statistically significant heterogeneity was identified in meta-regression according to tumor subsite (RR = 1.06, 95%CI = 0.97 – 1.17, RR = 1.08, 95%CI = 0.99 – 1.18 for male and female proximal colon cancer; RR = 1.51, 95%CI = 1.22 – 1.87, RR = 1.08, 95%CI = 0.98 – 1.19 for male and female distal colon cancer; and RR = 1.39, 95%CI = 1.1 – 1.77, RR = 1.51, 95%CI = 0.94 – 2.03 for male and female rectal cancer) or other factors, including age of BMI assessment, self-reported or measured BMI, and adjustment for smoking.

Conclusions

The results suggest that high early-life BMI is associated with increased risk of CRC in adulthood. Further studies should investigate adult CRC risk in early-life obese individuals from non-Western countries and the underlying mechanisms by which early-life adiposity may influence CRC pathogenesis.

Maternal stress and early-onset colorectal cancer

Early-onset colorectal cancer (EOCRC) is defined as colorectal cancer (CRC) diagnosed before the age of 50. Alarmingly, there has been a significant increase in EOCRC diagnoses' worldwide over the past several decades. Emerging data suggest EOCRCs have distinguishing clinical, pathological, biological and molecular features; and thus, are a fundamentally different subtype of CRCs. Unfortunately, there is no simple explanation for the causes of EOCRC. Scientifically rigorous studies are needed to determine what may be driving the challenging epidemiology of EOCRC. We contend here that a reasonable hypothesis is that prenatal risk factors such as maternal stress and associated sleeping disorders influence offspring epigenetic make-up, and shape immune system and gut health contributing to an increased risk for EOCRC.

Proportion and number of cancer cases and deaths attributable to potentially modifiable risk factors in the United States

Contemporary information on the fraction of cancers that potentially could be prevented is useful for priority setting in cancer prevention and control. Herein, the authors estimate the proportion and number of invasive cancer cases and deaths, overall (excluding nonmelanoma skin cancers) and for 26 cancer types, in adults aged 30 years and older in the United States in 2014, that were attributable to major, potentially modifiable exposures (cigarette smoking; secondhand smoke; excess body weight; alcohol intake; consumption of red and processed meat; low consumption of fruits/vegetables, dietary fiber, and dietary calcium; physical inactivity; ultraviolet radiation; and 6 cancer-associated infections). The numbers of cancer cases were obtained from the Centers for Disease Control and Prevention (CDC) and the National Cancer Institute; the numbers of deaths were obtained from the CDC; risk factor prevalence estimates were obtained from nationally representative surveys; and associated relative risks of cancer were obtained from published, large-scale pooled analyses or meta-analyses. In the United States in 2014, an estimated 42.0% of all incident cancers (659,640 of 1570,975 cancers, excluding nonmelanoma skin cancers) and 45.1% of cancer deaths (265,150 of 587,521 deaths) were attributable to evaluated risk factors. Cigarette smoking accounted for the highest proportion of cancer cases (19.0%; 298,970 cases) and deaths (28.8%; 169,180 deaths), followed by excess body weight (7.8% and 6.5%, respectively) and alcohol intake (5.6% and 4.0%, respectively). Lung cancer had the highest number of cancers (184,970 cases) and deaths (132,960 deaths) attributable to evaluated risk factors, followed by colorectal cancer (76,910 cases and 28,290 deaths). These results, however, may underestimate the overall proportion of cancers attributable to modifiable factors, because the impact of all established risk factors could not be quantified, and many likely modifiable risk factors are not yet firmly established as causal. Nevertheless, these findings underscore the vast potential for reducing cancer morbidity and mortality through broad and equitable implementation of known preventive measures. CA Cancer J Clin 2018;68:31-54. © 2017 American Cancer Society.

NK cells in childhood obesity are activated, metabolically stressed, and functionally deficient

Childhood obesity is a major global concern, with over 50 million children now classified as obese. Obesity has been linked to the development of numerous chronic inflammatory diseases, including type 2 diabetes and multiple cancers. NK cells are a subset of innate effector cells, which play an important role in the regulation of adipose tissue and antitumor immunity. NK cells can spontaneously kill transformed cells and coordinate subsequent immune responses through their production of cytokines. We investigated the effect of obesity on NK cells in a cohort of obese children, compared to children with a healthy weight. We demonstrated a reduction in peripheral NK cell frequencies in childhood obesity and inverse correlations with body mass index and insulin resistance. Compared with NK cells from children with normal weight, we show increased NK cell activation and metabolism in obese children (PD-1, mTOR activation, ECAR, and mitochondrial ROS), along with a reduced capacity to respond to stimulus, ultimately leading to loss of function (proliferation and tumor lysis). Collectively we show that NK cells from obese children are activated, metabolically stressed, and losing the ability to perform their basic duties. Paired with the reduction in NK cell frequencies in childhood obesity, this suggests that the negative effect on antitumor immunity is present early in the life course of obesity and certainly many years before the development of overt malignancies.