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

Effect modification in the impacts of body mass index change on the risk of colorectal cancer in middle-aged and older adults

BACKGROUND

Effect modification by cofactors in the association between body mass index (BMI) change and colorectal cancer (CRC) risk has rarely been investigated.

METHODS

Cancer-free individuals who participated in the national health examinations and cancer screening at 2010 and underwent national health examination at 2014, were enrolled and followed through 2021 RESULTS: Among 3.8 million, 42,555 patients developed CRCs. Persistent high BMI increased CRC risk comparing to persistent normal BMI. Among overweight individuals, BMI loss reduced CRC risk (adjusted hazard ratios [aHR] 0.93; 95 % confidence intervals [CIs] 0.88-0.99) and marked BMI gain (overweight to obesity II) increased CRC risk (aHR 1.91; 95 % CI 1.11-3.29). The impact of BMI change on CRC risk was significant across sex, age, and smoking status, with stronger effects in women, especially postmenopausal women. Persistent underweight in individuals over 50 years increased CRC risk (aHR 1.19; 95 % CI 1.05-1.34). Marked BMI gain increased CRC risk in men (normal to obesity I; aHR 1.21; 95 % CI 1.02-1.44) and women (overweight to obesity II; aHR 2.08; 95 % CI 1.16-3.74).

CONCLUSIONS

These results highlight the hazardousness of persistent high BMI and further BMI gain with effect modification by cofactors.

The burden of colorectal cancer attributable to high body mass index in China: findings from 1990 to 2021 and prediction to 2035

BACKGROUND

Colorectal cancer (CRC) incidence and mortality are rising in China, with high body mass index (BMI) established as a significant risk factor. However, comprehensive evidence regarding the BMI-attributable CRC burden in the Chinese population remains limited.

OBJECTIVE

This study aims to analyze the trend of CRC burden attributable to high BMI (BMI ≥ 25 kg/m2) in China from 1990 to 2021 and to predict its development from 2022 to 2035, in order to provide a scientific foundation for the formulation of public health policies.

METHODS

We analyzed data from the Global Burden of Disease Study 2021 (GBD 2021) to assess the BMI-attributable CRC burden in China from 1990 to 2021. Temporal trends were analyzed using Joinpoint regression models. Future projections through 2035 were generated using Bayesian age-period-cohort (BAPC) modeling. The Das Gupta method was used to explore the contribution of population growth, aging, and epidemiologic factors to these burden changes.

RESULTS

From 1990 to 2021, China's BMI-attributable CRC burden increased substantially, with ASMR and ASDR rising at annual rates of 2.393% (95% CI 2.306-2.481) and 2.305% (95% CI 2.188-2.422), respectively. The mortality and disability-adjusted life years (DALYs) rate both increased with age. Males showed higher burden rates in most age groups. Projections indicate continued increases in ASMR (2.43% annually) and ASDR (2.44% annually) through 2035. Epidemiological factors were the primary drivers, contributing 99.73% to mortality changes and 44.81% to DALYs changes.

CONCLUSIONS

The BMI-attributable CRC burden in China shows a concerning upward trajectory that is predicted to continue, with epidemiologic factors playing a major role. Urgent public health interventions targeting obesity prevention, lifestyle modification, and expanded CRC screening are needed to mitigate this growing burden.

Association of overweight/obesity and digestive system cancers: A meta-analysis and trial sequential analysis of prospective cohort studies

BACKGROUND

Previous researches have reported correlations between overweight/obesity and common digestive system cancers (DSCs), including gastric, liver, esophageal, colorectal, and pancreatic cancers. However, the inconsistency in defining overweight/obesity and the risk of recall bias from case-control and retrospective cohort studies may influence existing results. Therefore, we aimed to validate the relationship between overweight/obesity and common DSCs by combining prospective cohort studies based on the World Health Organization (WHO) criteria for defining overweight/obesity.

METHODS

A comprehensive literature search was conducted across PubMed, Embase, Web of Science, and Cochrane databases, covering all publications up to February 7, 2024. The inclusion criteria focused on prospective cohort studies that examined the link between overweight/obesity and risks of DSCs. R software 4.1.3 and STATA 12 were utilised to calculate the relative risk (RR), with 95% confidence interval (CI) and prediction interval (PI). TSA v0.9.5.10 Beta software was used for trial sequential analysis (TSA).

RESULTS

The meta-analysis encompassed 39 articles. The overall analysis showed that compared with normal weight, overweight/obesity increased the risks of liver cancer (overweight: RR [95% CI] =  1.237 [1.112-1.377]; 95% PI: 0.888-1.725; obesity: RR [95% CI] =  1.642 [1.466-1.839]; 95% PI: 1.143-2.358) and colorectal cancer (overweight: RR [95% CI] =  1.124 [1.056-1.197]; 95% PI: 0.931-1.357; obesity: RR [95% CI] =  1.366 [1.242-1.503]; 95% PI: 0.959-1.945) in the total population. Subgroup analysis revealed that overweight (RR [95% CI] =  1.237 [1.165-1.314]; 95% PI: 1.154-1.327) and obesity (RR [95% CI] =  1.306 [1.152-1.480]; 95% PI: 1.108-1.539) were associated with an increased risk of pancreatic cancer only in women, and overweight also increased the gastric cancer risk of women (RR [95% CI] =  1.041 [1.013-1.070], 95% PI: 0.806-1.230). No significant association of overweight/obesity and esophageal cancer was observed in both male and female.

CONCLUSION

Our study suggested that overweight/obesity elevated the risks of liver and colorectal cancer in both men and women. No significant association was found between overweight/obesity and the risk of developing esophageal cancer. Clinicians are advised to consider weight control as an effective measure for preventing pancreatic, liver, and colorectal cancers.

Cancer, malnutrition and inflammatory biomarkers. Why do some cancer patients lose more weight than others?

Introduction

Malnutrition is highly prevalent in cancer patients, significantly influencing their clinical outcomes and prognosis. The study was conducted to investigate the association between inflammatory biomarkers, nutritional status and progression of the disease across various types of cancers.

Material and methods

Retrospective data from 200 consecutive Caucasian cancer patients admitted to a major oncology hospital for cancer treatment were analyzed according to age, sex, cancer type, nutritional status (percentage body weight loss - %BWL), body mass index (BMI), percentage of dietary intake from the calculated requirement for nutrients (%DI)), and laboratory results (albumin levels, total protein concentration, C-reactive protein - CRP). Inflammatory biomarkers such as prognostic nutritional index (PNI), neutrophil-to-lymphocyte ratio (NLR), and platelet-to-lymphocyte ratio (PLR) were assessed.

Results

Prognostic nutritional index (ρ = -0.464, p < 0.001), PLR (ρ = 0.293, p = 0.019), albumin level (ρ = -0.490, p < 0.001), platelet count (ρ = 0.114, p = 0.370), neutrophil count (ρ = 0.273, p = 0.030), CRP (ρ = 0.293, p = 0.019) and lymphocyte count (ρ = -0.288, p = 0.021) were significantly associated with %BWL. No significant association was found with NLR. Cancer dissemination was significantly associated with PNI (OR: 0.93, 95% CI: 0.88-0.98), PLR (OR: 1.00, 95% CI: 1.00-1.01), albumin (OR: 0.86, 95% CI: 0.80-0.93), platelet count (OR: 1.01, 95% CI: 1.00-1.01), %BWL (OR: 1.06, 95% CI: 1.02-1.10) and %DI (OR: 0.97, 95% CI: 0.96-0.99) but not with NLR, total protein level, total lymphocyte count, or BMI. For patients with albumin levels below 35 g/l, the likelihood of disseminated cancer was more than five times higher (OR: 5.45, 95% CI: 2.05-14.48).

Conclusions

The intensity of inflammation may be responsible for the severity of malnutrition and cancer prognosis.

Age and sex differences in the relationship of body weight changes with colon cancer risks: A nationwide cohort study

Colon cancer is a significant health concern, and obesity is a well-established risk factor. However, previous studies have mainly focused on assessing body weight as a risk factor for colon cancer at a specific time point. This nationwide cohort study investigated the association between body weight changes, which can fluctuate throughout an individual's lifespan, and the incidence of colon cancer using the South Korean population database provided by the National Health Insurance Service (NHIS). Participants who underwent biennial health screenings between 2004 and 2006, and had follow-up health check-ups between 2014 and 2016, were included in this study. Body weight changes were categorized as follows: < 5%, decrease 5-20%, decrease > 20%, increase 5-20%, or > 20%. The primary outcome was the incidence of newly diagnosed colon cancer. Statistical analysis was used to examine the relationship between body weight changes and the incidence of colon cancer stratified according to age and sex. The Kaplan-Meier method estimated the cumulative incidence of colon cancer, and Cox proportional hazards models were used to calculate hazard ratios (HR) and 95% confidence intervals (CI), adjusting for confounding factors. The analysis included data from 10,332,397 individuals, with a mean (± SD) age of 45.5 ± 13.1 years, and 54.9% were male. In males with a body mass index (BMI) range of 18-30 kg/m2, both a weight gain of 5-20% (HR 1.07, P > z 0.01 [95% CI 1.02-1.13]) and weight gain > 20% (HR 1.27, P > z 0.03 [95% CI 1.03-1.56]) were associated with an increased risk for colon cancer. In addition, males < 40 years of age exhibited a higher risk for colon cancer with > 20% weight gain (HR 1.65, P > z < 0.001 [95% CI 1.18-2.30]). Whereas, females within the BMI range of 18-30 kg/m2 who exhibited > 20% weight loss demonstrated a reduced risk (HR 0.77, P > z 0.04 [95% CI 0.60-0.98]). Moreover, females ≥ 40 years of age, who experienced weight loss > 20%, exhibited a decreased risk for colon cancer (HR 0.76; P > 0.02 [95% CI 0.60-0.96]). This nationwide cohort study demonstrated a relationship between body weight changes and the incidence of colon cancer, with differences based on sex and age. In particular, avoiding weight gain is crucial for males < 40 years of age, whereas weight loss could be beneficial for females > 40 years of age in reducing the risk of colon cancer.

Association of hTERT Gene Polymorphism and Colorectal Cancer (CRC) Risk in the Chinese Han Population

The catalytic subunit telomerase reverse transcriptase (hTERT) is a prerequisite for malignant transformation of human cells. Colorectal cancer (CRC) is a common malignant tumor. The genetic association of hTERT gene rs2853669 and rs2736098 polymorphisms with CRC was surveyed in the Chinese population. Two hundreds patients with CRC and 200 healthy controls were taken for blood sample collection. Sanger sequencing was applied for genotyping. Multiple logistic regression analysis was performed, and odds ratio (OR) together with confidence interval (CI) were calculated to obtain the corresponding association power. Among CRC cases (49.50%), hTERT gene rs2736098 GA genotype carriers were more prevalent compared with the control group (41.00%, P = 0.035), which increased the risk of CRC by 1.576 times (95% CI, 1.031-2.409). Distribution of the rs2736098 genotypes was significantly associated with TNM stage, tumor differentiation, tumor size and lymph node metastasis (P < 0.05). The frequencies of hTERT gene rs2853669 polymorphism were not significantly different between CRC patients and healthy controls. Logistic regression analysis indicated that both body mass index (BMI) and hTERT gene rs2736098 polymorphism remained significantly correlated with CRC susceptibility. The frequencies of hTERT gene rs2853669 polymorphism did not differ significantly between CRC patients and control group (P > 0.05). The hTERT gene rs2736098 polymorphism was correlated with CRC risk in the Chinese Han population, and the GA genotype was a risk element for the onset of CRC.

Anthropometric indicators may explain the high incidence of follicular lymphoma in Europeans: Results from a bidirectional two-sample two-step Mendelian randomisation

BACKGROUND

Non-Hodgkin's lymphoma incidence rates vary between European and Asian populations. The reasons remain unclear. This two-sample two-step Mendelian randomisation (MR) study aimed to investigate the causal relationship between anthropometric indicators (AIs) and diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma (FL) and the possible mediating role of basal metabolic rate (BMR) in Europe.

METHODS

We used the following AIs as exposures: body mass index (BMI), whole-body fat mass (WBFM), whole-body fat-free mass (WBFFM), waist circumference(WC), hip circumference(HC), standing height (SH), and weight(Wt). DLBCL and FL represented the outcomes, and BMR was a mediator. A two-sample MR analysis was performed to examine the association between AIs and DLBCL and FL onset. We performed reverse-MR analysis to determine whether DLBCL and FL interfered with the AIs. A two-step MR analysis was performed to determine whether BMR mediated the causality.

FINDINGS

WBFFM and SH had causal relationships with FL. A causal association between AIs and DLBCL was not observed. Reverse-MR analysis indicated the causal relationships were not bidirectional. Two-step MR suggested BMR may mediate the causal effect of WBFFM and SH on FL.

CONCLUSIONS

We observed a causal relationship between WBFFM and SH and the onset of FL in Europeans, Which may explain the high incidence of follicular lymphoma in Europeans.

Microbiome confounders and quantitative profiling challenge predicted microbial targets in colorectal cancer development

Despite substantial progress in cancer microbiome research, recognized confounders and advances in absolute microbiome quantification remain underused; this raises concerns regarding potential spurious associations. Here we study the fecal microbiota of 589 patients at different colorectal cancer (CRC) stages and compare observations with up to 15 published studies (4,439 patients and controls total). Using quantitative microbiome profiling based on 16S ribosomal RNA amplicon sequencing, combined with rigorous confounder control, we identified transit time, fecal calprotectin (intestinal inflammation) and body mass index as primary microbial covariates, superseding variance explained by CRC diagnostic groups. Well-established microbiome CRC targets, such as Fusobacterium nucleatum, did not significantly associate with CRC diagnostic groups (healthy, adenoma and carcinoma) when controlling for these covariates. In contrast, the associations of Anaerococcus vaginalis, Dialister pneumosintes, Parvimonas micra, Peptostreptococcus anaerobius, Porphyromonas asaccharolytica and Prevotella intermedia remained robust, highlighting their future target potential. Finally, control individuals (age 22-80 years, mean 57.7 years, standard deviation 11.3) meeting criteria for colonoscopy (for example, through a positive fecal immunochemical test) but without colonic lesions are enriched for the dysbiotic Bacteroides2 enterotype, emphasizing uncertainties in defining healthy controls in cancer microbiome research. Together, these results indicate the importance of quantitative microbiome profiling and covariate control for biomarker identification in CRC microbiome studies.

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.

Trends in BMI of Indonesian adults between 1993 and 2014: a longitudinal population-based study

OBJECTIVE

To examine the trajectories of BMI in Indonesian adults from 1993 to 2014, investigating different patterns by sex and birth cohort.

DESIGN

Longitudinal study: secondary data analysis of the Indonesian Family Life Survey, a large-scale population-based longitudinal study, had their height and weight measured up to five times throughout the 21-year study period (1993-2014). The change in BMI across time was estimated using group-based trajectory models, then differences by sex and birth cohort were investigated using random effect (mixed) models.

SETTING

Thirteen out of twenty-seven provinces in Indonesia.

PARTICIPANTS

Indonesian adults aged 19 years and older (n 42 537) were included in the analysis.

RESULTS

Mean BMI in adults increased between 1993 (21·4 kg/m2) and 2014 (23·5 kg/m2). The group-based trajectory model found three distinct groups with mean BMI increasing more rapidly in the most recent time periods. The first group (56·7 % of participants) had a mean BMI entirely within the normal weight range; the second group (34·7 %) started in the normal weight category and were obese, on average by the end of the study period; and the third group (8·6 %) were always in the obese category, on average. The shape of these three trajectories differed by gender (P < 0·001) and birth cohort (P < 0·001).

CONCLUSIONS

The mean BMI among Indonesian adults has increased between 1993 and 2014, driven by those in the most recent birth cohorts. Our findings support the urgent need for targeted overweight and obesity prevention and intervention programmes in Indonesia.

Analysis of Body Mass Index in Early and Middle Adulthood and Estimated Risk of Gastrointestinal Cancer

Importance

In a population with significantly increasing rates of individuals with overweight or obesity, understanding the association of obesity with long-term disease risk, such as cancer, is necessary to improve public health.

Objective

To investigate the association between body mass index (BMI) and gastrointestinal (GI) cancer risk (colorectal cancer [CRC] and noncolorectal GI cancer) in the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial.

Design, Setting, and Participants

This retrospective cohort study was a secondary analysis of data from the PLCO Cancer Screening Trial. Participants aged 55 to 74 years were enrolled and randomized to the intervention (screening group) or control group at 10 screening centers between November 8, 1993, and July 2, 2001. The initial analysis of PLCO Cancer Screening Trial data occurred after 13 years of follow-up or December 31, 2009, whichever came first. Participants were reconsented in 2011 and either continued follow-up or refused additional follow-up. For those who reconsented, follow-up for incident cancers continued until December 31, 2014, or death, whichever occurred first. Data analysis for this secondary analysis was performed from April 2022 through November 2022.

Exposures

Body mass index and aspirin use, defined as the frequency of use of aspirin or aspirin-containing substances in the last 12 months.

Main Outcomes and Measures

The primary outcomes were the diagnoses of CRC and noncolorectal GI cancer. The association between BMI and cancer (CRC and noncolorectal GI cancer) was assessed using Cox proportional hazards regression modeling. The association between cancer risk and change in BMI was further analyzed at different ages, and an exploratory analysis was performed to evaluate GI cancer risk among aspirin users.

Results

This analysis included 135 161 participants (median [range] age, 62 [55-78] years; 67 643 [50.0%] female). Overweight BMI in early adulthood (hazard ratio [HR], 1.23; 95% CI, 1.10-1.37) and overweight BMI in middle adulthood (HR, 1.23; 95% CI, 1.13-1.34) and later adulthood (HR, 1.21; 95% CI, 1.10-1.32) as well as obese BMI in middle adulthood (HR, 1.55; 95% CI, 1.38-1.75) and later adulthood (HR, 1.39; 95% CI, 1.25-1.54) were associated with increased risk of CRC. Similar results were observed for the association with overall GI and non-CRC GI risk and BMI in middle and later adulthood. Maintaining overweight or obese BMI or increasing BMI to overweight or obese in later adulthood was also associated with increased CRC risk. Aspirin use 3 or more times per week did not significantly modify this association.

Conclusions and Relevance

In this secondary analysis of the PLCO Cancer Screening Trial, overweight and obese BMI in early and middle adulthood was associated with an elevated risk of CRC and noncolorectal GI cancers. The results of the current study prompt further exploration into the mechanistic role of obese BMI in carcinogenesis.

Estimation and Inference for High-Dimensional Generalized Linear Models with Knowledge Transfer

Transfer learning provides a powerful tool for incorporating data from related studies into a target study of interest. In epidemiology and medical studies, the classification of a target disease could borrow information across other related diseases and populations. In this work, we consider transfer learning for high-dimensional generalized linear models (GLMs). A novel algorithm, TransHDGLM, that integrates data from the target study and the source studies is proposed. Minimax rate of convergence for estimation is established and the proposed estimator is shown to be rate-optimal. Statistical inference for the target regression coefficients is also studied. Asymptotic normality for a debiased estimator is established, which can be used for constructing coordinate-wise confidence intervals of the regression coefficients. Numerical studies show significant improvement in estimation and inference accuracy over GLMs that only use the target data. The proposed methods are applied to a real data study concerning the classification of colorectal cancer using gut microbiomes, and are shown to enhance the classification accuracy in comparison to methods that only use the target data.

Subtyping Patients With Chronic Disease Using Longitudinal BMI Patterns

Obesity is a major health problem, increasing the risk of various major chronic diseases, such as diabetes, cancer, and stroke. While the role of obesity identified by cross-sectional BMI recordings has been heavily studied, the role of BMI trajectories is much less explored. In this study, we use a machine learning approach to subtype individuals' risk of developing 18 major chronic diseases by using their BMI trajectories extracted from a large and geographically diverse EHR dataset capturing the health status of around two million individuals for a period of six years. We define nine new interpretable and evidence-based variables based on the BMI trajectories to cluster the patients into subgroups using the k-means clustering method. We thoroughly review each cluster's characteristics in terms of demographic, socioeconomic, and physiological measurement variables to specify the distinct properties of the patients in the clusters. In our experiments, the direct relationship of obesity with diabetes, hypertension, Alzheimer's, and dementia has been re-established and distinct clusters with specific characteristics for several of the chronic diseases have been found to be conforming or complementary to the existing body of knowledge.

Dysbiotic microbiome variation in colorectal cancer patients is linked to lifestyles and metabolic diseases

BACKGROUND

Differences in the composition and diversity of the gut microbial communities among individuals are influenced by environmental factors. However, there is limited research on factors affecting microbiome variation in colorectal cancer patients, who display lower inter-individual variations than that of healthy individuals. In this study, we examined the association between modifiable factors and the microbiome variation in colorectal cancer patients.

METHODS

A total of 331 colorectal cancer patients who underwent resection surgery at the Department of Surgery, Seoul National University Hospital between October 2017 and August 2019 were included. Fecal samples from colorectal cancer patients were collected prior to the surgery. Variations in the gut microbiome among patients with different lifestyles and metabolic diseases were examined through the network analysis of inter-connected microbial abundance, the assessment of the Anna Karenina principle effect for microbial stochasticity, and the identification of the enriched bacteria using linear discrimination analysis effect size. Associations of dietary diversity with microbiome variation were investigated using the Procrustes analysis.

RESULTS

We found stronger network connectivity of microbial communities in non-smokers, non-drinkers, obese individuals, hypertensive subjects, and individuals without diabetes than in their counterparts. The Anna Karenina principle effect was found for history of smoking, alcohol consumption, and diabetes (with significantly greater intra-sample similarity index), whereas obesity and hypertension showed the anti-Anna Karenina principle effect (with significantly lower intra-sample similarity index). We found certain bacterial taxa to be significantly enriched in patients of different categories of lifestyles and metabolic diseases using linear discrimination analysis. Diversity of food and nutrient intake did not shape the microbial diversity between individuals (p_Procrustes>0.05).

CONCLUSIONS

Our findings suggested an immune dysregulation and a reduced ability of the host and its microbiome in regulating the community composition. History of smoking, alcohol consumption, and diabetes were shown to affect partial individuals in shifting new microbial communities, whereas obesity and history of hypertension appeared to affect majority of individuals and shifted to drastic reductions in microbial compositions. Understanding the contribution of modifiable factors to microbial stochasticity may provide insights into how the microbiome regulates effects of these factors on the health outcomes of colorectal cancer patients.

Causal inference under over-simplified longitudinal causal models

Many causal models of interest in epidemiology involve longitudinal exposures, confounders and mediators. However, repeated measurements are not always available or used in practice, leading analysts to overlook the time-varying nature of exposures and work under over-simplified causal models. Our objective is to assess whether - and how - causal effects identified under such misspecified causal models relates to true causal effects of interest. We derive sufficient conditions ensuring that the quantities estimated in practice under over-simplified causal models can be expressed as weighted averages of longitudinal causal effects of interest. Unsurprisingly, these sufficient conditions are very restrictive, and our results state that the quantities estimated in practice should be interpreted with caution in general, as they usually do not relate to any longitudinal causal effect of interest. Our simulations further illustrate that the bias between the quantities estimated in practice and the weighted averages of longitudinal causal effects of interest can be substantial. Overall, our results confirm the need for repeated measurements to conduct proper analyses and/or the development of sensitivity analyses when they are not available.

Body Size at Different Ages and Risk of 6 Cancers: A Mendelian Randomization and Prospective Cohort Study

It is unclear if body weight in early life affects cancer risk independently of adult body weight. To investigate this question for 6 obesity-related cancers, we performed univariable and multivariable analyses using 1) Mendelian randomization (MR) analysis and 2) longitudinal analyses in prospective cohorts. Both the MR and longitudinal analyses indicated that larger early life body size was associated with higher risk of endometrial (odds ratioMR = 1.61, 95% confidence interval = 1.23 to 2.11) and kidney (odds ratioMR = 1.40, 95% confidence interval = 1.09 to 1.80) cancer. These associations were attenuated after accounting for adult body size in both the MR and cohort analyses. Early life body mass index (BMI) was not consistently associated with the other investigated cancers. The lack of clear independent risk associations suggests that early life BMI influences endometrial and kidney cancer risk mainly through pathways that are common with adult BMI.

BMI trajectories, morbidity, and mortality in England: a two-step approach to estimating consequences of changes in BMI

OBJECTIVE

BMI is known to have an association with morbidities and mortality. Many studies have argued that identifying health risks using single BMI measures has limitations, particularly in older adults, and that changes in BMI can help to identify risks. This study identifies distinct BMI trajectories and their association with the risks of a range of morbidities and mortality.

METHODS

The English Longitudinal Study of Aging provides data on BMI, mortality, and morbidities between 1998 and 2015, sampled from adults over 50 years of age. This study uses a growth-mixture model and discrete-time survival analysis, combined using a two-step approach, which is novel in this setting, to the authors' knowledge.

RESULTS

This study identified four trajectories: "stable overweight," "elevated BMI," "increasing BMI," and "decreasing BMI." No differences in mortality, cancer, or stroke risk were found between these trajectories. BMI trajectories were significantly associated with the risks of diabetes, asthma, arthritis, and heart problems.

CONCLUSIONS

These results emphasize the importance of looking at change in BMI alongside most recent BMI; BMI trajectories should be considered where possible when assessing health risks. The results suggest that established BMI thresholds should not be used in isolation to identify health risks, particularly in older adults.

Body mass index trajectories, weight gain and risks of liver and biliary tract cancers

BACKGROUND

Little is known about the role of early obesity or weight change during adulthood in the development of liver cancer and biliary tract cancer (BTC).

METHODS

We investigated the associations of body mass index (BMI) and weight trajectories with the risk of liver cancer and BTC in the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial (PLCO). BMI was self-reported at ages 20, 50, and at enrollment. BMI trajectories were determined using latent class growth models. Cox regression was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

During a median follow-up of 15.9 years among 138,922 participants, 170 liver cancer and 143 BTC cases were identified. Compared with those whose BMI does not exceed 25 kg/m2, participants with BMI exceeding 25 kg/m2 at age 20 had increased risks of liver cancer (HR = 2.03, 95% CI: 1.26-3.28) and BTC (HR = 1.99, 95% CI: 1.16-3.39). Compared to participants maintaining normal BMI until enrollment, trajectory of normal weight at age 20 to obesity at enrollment was associated with increased risk for liver cancer (HR = 2.50, 95% CI: 1.55-4.04) and BTC (HR = 1.83, 95% CI: 1.03-3.22). Compared to adults with stable weight (+/-5kg) between age 20 to 50 years, weight gain ≥20 kg between ages 20 to 50 years had higher HRs of 2.24 (95%CI: 1.40-3.58) for liver cancer and 1.86 (95% CI: 1.12-3.09) for BTC.

CONCLUSIONS

Being overweight/obese at age 20, and BMI trajectories that result in being overweight and/or obese, may increase risk for both liver cancer and BTC.

Body Mass Index and Other Risk Factors Effects on Colon Cancer Prognosis in Pakistan

INTRODUCTION

Asian developing countries share the burden of colorectal cancer (CRC) with rising mortality rates. This prospective study aims to apprehend the clinical relevance of age, gender, lifestyle choices (dietary habits and addiction) and body mass index (BMI) to the occurrence and progression of colon cancer (CC).

METHODS

A cohort of non-cancer (NC) and CC patients of South-Central Asian origin registered for screening colonoscopy or surgery at Shaukat Khanum Memorial Cancer Hospital and Research Centre (SKMCH and RC), Lahore, Pakistan, from 2015 to 2020 was identified. BMI (Kg/m2) was classified according to the World Health Organization criteria as underweight (<18.5 Kg/m2), normal weight (18.5-24.9 Kg/m2) and overweight (≥25 Kg/m2).

RESULTS

Among 236 participants, 99 (41.9%) belonged to the NC group, and 137 (58.1 %) participants had CC Overall, participants included 74 women and 162 men aged 20-85 years (mean ± SD; 49.9 ± 14.9). Notably, 46.0% of cancer patients had a family history of cancer. There was a direct relationship between CC with abnormal BMI (underweight and overweight), positive smoking history and positive family history of cancer.

CONCLUSION

Being underweight or overweight is a potential risk factor for CC patients. The overall survival in patients with CC is clinically associated with lifestyle choices before CC diagnosis. A balanced diet, walking and other forms of exercise should be strongly recommended to the community and those undergoing screening colonoscopy.

Body Mass Index and Other Risk Factors Effects on Colon Cancer Prognosis in Pakistan

INTRODUCTION

Asian developing countries share the burden of colorectal cancer (CRC) with rising mortality rates. This prospective study aims to apprehend the clinical relevance of age, gender, lifestyle choices (dietary habits and addiction) and body mass index (BMI) to the occurrence and progression of colon cancer (CC).

METHODS

A cohort of non-cancer (NC) and CC patients of South-Central Asian origin registered for screening colonoscopy or surgery at Shaukat Khanum Memorial Cancer Hospital and Research Centre (SKMCH and RC), Lahore, Pakistan, from 2015 to 2020 was identified. BMI (Kg/m2) was classified according to the World Health Organization criteria as underweight (<18.5 Kg/m2), normal weight (18.5-24.9 Kg/m2) and overweight (≥25 Kg/m2).

RESULTS

Among 236 participants, 99 (41.9%) belonged to the NC group, and 137 (58.1 %) participants had CC Overall, participants included 74 women and 162 men aged 20-85 years (mean ± SD; 49.9 ± 14.9). Notably, 46.0% of cancer patients had a family history of cancer. There was a direct relationship between CC with abnormal BMI (underweight and overweight), positive smoking history and positive family history of cancer.

CONCLUSION

Being underweight or overweight is a potential risk factor for CC patients. The overall survival in patients with CC is clinically associated with lifestyle choices before CC diagnosis. A balanced diet, walking and other forms of exercise should be strongly recommended to the community and those undergoing screening colonoscopy.

The timing of adiposity and changes in the life course on the risk of cancer

Excess body weight has been established as a risk factor for at least twelve cancer sites, though questions remain as to the timing of associations for adiposity and cancer risk throughout the life course. We conducted a narrative review summarizing existing evidence to provide insights into the complex timing relationship between adiposity and risk of seven common obesity-related cancers. We considered five types of studies, including traditional epidemiologic studies examining adiposity at different time points, studies examining weight gain in specific life phases, studies examining weight loss over a period including from bariatric surgery, life course trajectory analysis, and Mendelian randomization studies. The results showed that lifetime excess body weight is associated with increased risk of cancers of endometrium, colorectum, liver, kidney, and pancreas. Early life obesity is one of the strongest risk factors for pancreatic cancer but less directly important than adult obesity for endometrial and kidney cancer. Interestingly, heavy weight during childhood, adolescence, and early adulthood is protective against pre- and postmenopausal breast cancer and possibly advanced prostate cancer. It is apparent that preventing weight gain later in adulthood would likely reduce risk of many cancers, including postmenopausal breast cancer, endometrial cancer, colorectal cancer (especially in men), liver cancer, kidney cancer, and probably advanced prostate cancer. Furthermore, weight loss even late in life may confer benefits for cancers of breast, endometrium, colorectum, and liver among patients with obesity, as mostly demonstrated by studies of bariatric surgery. Overall, maintaining a healthy weight throughout the life course will help prevent a large number of cancers.

Alcohol intake trajectories during the life course and risk of alcohol-related cancer: A prospective cohort study

We examined associations between sex-specific alcohol intake trajectories and alcohol-related cancer risk using data from 22 756 women and 15 701 men aged 40 to 69 years at baseline in the Melbourne Collaborative Cohort Study. Alcohol intake for 10-year periods from age 20 until the decade encompassing recruitment, calculated using recalled beverage-specific frequency and quantity, was used to estimate group-based sex-specific intake trajectories. Hazard ratios (HR) and 95% confidence intervals (CI) were estimated for primary invasive alcohol-related cancer (upper aerodigestive tract, breast, liver and colorectum). Three distinct alcohol intake trajectories for women (lifetime abstention, stable light, increasing moderate) and six for men (lifetime abstention, stable light, stable moderate, increasing heavy, early decreasing heavy, late decreasing heavy) were identified. 2303 incident alcohol-related cancers were diagnosed during 485 525 person-years in women and 789 during 303 218 person-years in men. For men, compared with lifetime abstention, heavy intake (mean ≥ 60 g/day) at age 20 to 39 followed by either an early (from age 40 to 49) (early decreasing heavy; HR = 1.75, 95% CI: 1.25-2.44) or late decrease (from age 60 to 69) (late decreasing heavy; HR = 1.94, 95% CI: 1.28-2.93), and moderate intake (mean <60 g/day) at age 20 to 39 increasing to heavy intake in middle-age (increasing heavy; HR = 1.45, 95% CI: 1.06-1.97) were associated with increased risk of alcohol-related cancer. For women, compared with lifetime abstention, increasing intake from age 20 (increasing moderate) was associated with increased alcohol-related cancer risk (HR = 1.25, 95% CI: 1.06-1.48). Similar associations were observed for colorectal (men) and breast cancer. Heavy drinking during early adulthood might increase cancer risk later in life.

Associations of genetic risk, BMI trajectories, and the risk of non-small cell lung cancer: a population-based cohort study

BACKGROUND

Body mass index (BMI) has been found to be associated with a decreased risk of non-small cell lung cancer (NSCLC); however, the effect of BMI trajectories and potential interactions with genetic variants on NSCLC risk remain unknown.

METHODS

Cox proportional hazards regression model was applied to assess the association between BMI trajectory and NSCLC risk in a cohort of 138,110 participants from the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial. One-sample Mendelian randomization (MR) analysis was further used to access the causality between BMI trajectories and NSCLC risk. Additionally, polygenic risk score (PRS) and genome-wide interaction analysis (GWIA) were used to evaluate the multiplicative interaction between BMI trajectories and genetic variants in NSCLC risk.

RESULTS

Compared with individuals maintaining a stable normal BMI (n = 47,982, 34.74%), BMI trajectories from normal to overweight (n = 64,498, 46.70%), from normal to obese (n = 21,259, 15.39%), and from overweight to obese (n = 4,371, 3.16%) were associated with a decreased risk of NSCLC (hazard ratio [HR] for trend = 0.78, P < 2×10-16). An MR study using BMI trajectory associated with genetic variants revealed no significant association between BMI trajectories and NSCLC risk. Further analysis of PRS showed that a higher GWAS-identified PRS (PRSGWAS) was associated with an increased risk of NSCLC, while the interaction between BMI trajectories and PRSGWAS with the NSCLC risk was not significant (PsPRS= 0.863 and PwPRS= 0.704). In GWIA analysis, four independent susceptibility loci (P < 1×10-6) were found to be associated with BMI trajectories on NSCLC risk, including rs79297227 (12q14.1, located in SLC16A7, Pinteraction = 1.01×10-7), rs2336652 (3p22.3, near CLASP2, Pinteraction = 3.92×10-7), rs16018 (19p13.2, in CACNA1A, Pinteraction = 3.92×10-7), and rs4726760 (7q34, near BRAF, Pinteraction = 9.19×10-7). Functional annotation demonstrated that these loci may be involved in the development of NSCLC by regulating cell growth, differentiation, and inflammation.

CONCLUSIONS

Our study has shown an association between BMI trajectories, genetic factors, and NSCLC risk. Interestingly, four novel genetic loci were identified to interact with BMI trajectories on NSCLC risk, providing more support for the aetiology research of NSCLC.

TRIAL REGISTRATION

http://www.

CLINICALTRIALS

gov , NCT01696968 .

Deep Learning Analysis of the Adipose Tissue and the Prediction of Prognosis in Colorectal Cancer

Research has shown that the lipid microenvironment surrounding colorectal cancer (CRC) is closely associated with the occurrence, development, and metastasis of CRC. According to pathological images from the National Center for Tumor diseases (NCT), the University Medical Center Mannheim (UMM) database and the ImageNet data set, a model called VGG19 was pre-trained. A deep convolutional neural network (CNN), VGG19CRC, was trained by the migration learning method. According to the VGG19CRC model, adipose tissue scores were calculated for TCGA-CRC hematoxylin and eosin (H&E) images and images from patients at Zhujiang Hospital of Southern Medical University and First People's Hospital of Chenzhou. Kaplan-Meier (KM) analysis was used to compare the overall survival (OS) of patients. The XCell and MCP-Counter algorithms were used to evaluate the immune cell scores of the patients. Gene set enrichment analysis (GSEA) and single-sample GSEA (ssGSEA) were used to analyze upregulated and downregulated pathways. In TCGA-CRC, patients with high-adipocytes (high-ADI) CRC had significantly shorter OS times than those with low-ADI CRC. In a validation queue from Zhujiang Hospital of Southern Medical University (Local-CRC1), patients with high-ADI had worse OS than CRC patients with low-ADI. In another validation queue from First People's Hospital of Chenzhou (Local-CRC2), patients with low-ADI CRC had significantly longer OS than patients with high-ADI CRC. We developed a deep convolution network to segment various tissues from pathological H&E images of CRC and automatically quantify ADI. This allowed us to further analyze and predict the survival of CRC patients according to information from their segmented pathological tissue images, such as tissue components and the tumor microenvironment.

Risk of Colorectal Cancer Associated With Lifetime Excess Weight

Importance

Excess weight is associated with increased cancer risk, but the risk may have been underestimated, as previous studies did not consider cumulative lifetime exposure.

Objective

To assess the association of cumulative lifetime excess weight with risk of colorectal cancer (CRC).

Design, Setting, and Participants

In a population-based case-control study conducted since 2003 in Germany, height and self-reported weight documented in 10-year increments starting at age 20 years up to the current age were obtained from 5635 individuals with CRC and 4515 persons serving as controls. Body mass index (BMI), calculated as weight in kilograms divided by height in meters squared, was calculated for each year of age from age 20 years to the current age by linear interpolation. Excess BMI (eBMI) at each year of age was determined as BMI - 25 and summed across ages to obtain the weighted number of years lived with overweight or obesity (WYOs), determined as year × eBMI. The eBMI was set to 0 in case of a BMI below 25. Associations with CRC risk were estimated for BMI at various ages and for WYOs by multiple logistic regression. Data analyses were performed from June 4, 2021, to December 17, 2021.

Main Outcomes and Measures

Relative risk of CRC according to lifetime exposure to excess weight compared with relative risks according to BMI at various ages.

Results

The mean (SD) age of the patients with CRC (n = 5635) was 68.4 (10.9) years; 3366 were men (59.7%); mean (SD) age of the control participants (n = 4515) was 68.5 (10.6) years; 2759 were men (61.1%). An association was observed between WYOs and CRC risk, with adjusted odds ratios (ORs) increasing from 1.25 (95% CI, 1.09-1.44) to 2.54 (95% CI, 2.24-2.89) from the first to the fourth quartile of WYOs compared with participants who remained within the normal weight range. Each SD increment in WYOs was associated with an increase of CRC risk by 55% (adjusted OR, 1.55; 95% CI, 1.46-1.64). This OR was higher than the OR per SD increase of eBMI at any single point of time, which ranged from 1.04 (95% CI, 0.93-1.16) to 1.27 (95% CI 1.16-1.39).

Conclusions and Relevance

The results of this case-control study suggest a greater role of cumulative lifetime excess weight for CRC risk than estimated by traditional analyses based on BMI measures taken at a single point.

Meta-Analysis of the Association between Dietary Inflammatory Index (DII) and Colorectal Cancer

The Dietary Inflammatory Index (DII) was extensively used to examine the inflammatory potential of diet related to colorectal cancer (CRC). This meta-analysis aimed to update the evidence of the association between the DII and CRC across various culture-specific dietary patterns. Literature search was performed through online databases (Scopus, Web of Science, PubMed, and EBSCOHost). Observational studies exploring the association between the DII and CRC, published between 2017 and 2021, were included. The risk ratio (RR) and 95% confidence interval (CI) were separately computed for 12 studies comparing the highest and lowest DII scores and for 3 studies that presented continuous DII scores. A high DII score was associated with a higher risk of CRC (RR:1.16; 95% CI, 1.05–1.27). In the subgroup analysis, significant associations were seen in cohort design (RR: 1.24; 95% CI, 1.06–1.44), those lasting for 10 years or longer (RR: 2.95; 95% CI, 2.47–3.52), and in adjustment factor for physical activity (RR: 1.13; 95% CI, 1.07–1.20). An increase of one point in the DII score elevates the risk of CRC by 1.34 (95% CI: 1.15–1.55) times. The findings call for standardized measurement of the inflammatory potential of diet in future studies to enable the establishment of global guidelines for CRC prevention.

Addressing Hispanic Obesity Disparities Using a Community Health Worker Model Grounded in Motivational Interviewing

PURPOSE

To determine whether Hispanic residents receiving the Healthy Fit intervention enhanced with Motivational Interviewing (MI) experienced greater improvements in body composition, relative to participants receiving the initial intervention.

DESIGN

Quasi-experimental evaluation.

SETTING

El Paso, Texas.

SAMPLE

Among 656 baseline participants, 374 (54%) completed the 12-month assessment.

INTERVENTION

In Healthy Fit, community health workers (CHWs) promote nutrition and exercise. To strengthen intrinsic motivation and help participants overcome barriers to change, we incorporated a 30-minute motivational interview into the baseline assessment. Follow-up phone calls at 1, 3, and 6 months were identical across conditions.

MEASURES

CHWs assessed body mass index (BMI) and body fat percentage (BFP) using a bioelectrical impedance scale.

ANALYSIS

Regression models estimated differences between intervention conditions on change in BMI and BFP from baseline to the 12-month assessment.

RESULTS

Participants receiving MI had 2.13 times higher odds of losing weight (OR = 2.14, 95% CI [1.30, 3.53], P = .003) and 2.59 times higher odds of reduced BFP (OR = 2.59, 95% CI [1.51, 4.41], P < .001), relative to initial intervention participants. MI participants lost an average of 1.23 kg (2.71 lbs.) and their BFP declined 2% over 12 months.

CONCLUSION

Findings suggest CHW use of MI is a promising approach for promoting incremental changes in diet and exercise, which Healthy Fit integrates into a low-cost intervention.

Multidisciplinary prevention and management strategies for colorectal cancer and cardiovascular disease

Colorectal cancer (CRC) and cardiovascular disease (CVD) are leading causes of morbidity and mortality worldwide. Their numerous shared and modifiable risk factors underscore the importance of effective prevention strategies for these largely preventable diseases. Conventionally regarded as separate disease entities, clear pathophysiological links and overlapping risk factors represent an opportunity for synergistic collaborative efforts of oncologists and cardiologists. In addition, current CRC treatment approaches can exert cardiotoxicity and thus increase CVD risk. Given the complex interplay of both diseases and increasing numbers of CRC survivors who are at increased risk for CVD, multidisciplinary cardio-oncological approaches are warranted for optimal patient care from primary prevention to acute disease treatment and long-term surveillance.

Weight change in middle adulthood and risk of cancer in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort

Obesity is a risk factor for several major cancers. Associations of weight change in middle adulthood with cancer risk, however, are less clear. We examined the association of change in weight and body mass index (BMI) category during middle adulthood with 42 cancers, using multivariable Cox proportional hazards models in the European Prospective Investigation into Cancer and Nutrition cohort. Of 241 323 participants (31% men), 20% lost and 32% gained weight (>0.4 to 5.0 kg/year) during 6.9 years (average). During 8.0 years of follow-up after the second weight assessment, 20 960 incident cancers were ascertained. Independent of baseline BMI, weight gain (per one kg/year increment) was positively associated with cancer of the corpus uteri (hazard ratio [HR] = 1.14; 95% confidence interval: 1.05-1.23). Compared to stable weight (±0.4 kg/year), weight gain (>0.4 to 5.0 kg/year) was positively associated with cancers of the gallbladder and bile ducts (HR = 1.41; 1.01-1.96), postmenopausal breast (HR = 1.08; 1.00-1.16) and thyroid (HR = 1.40; 1.04-1.90). Compared to maintaining normal weight, maintaining overweight or obese BMI (World Health Organisation categories) was positively associated with most obesity-related cancers. Compared to maintaining the baseline BMI category, weight gain to a higher BMI category was positively associated with cancers of the postmenopausal breast (HR = 1.19; 1.06-1.33), ovary (HR = 1.40; 1.04-1.91), corpus uteri (HR = 1.42; 1.06-1.91), kidney (HR = 1.80; 1.20-2.68) and pancreas in men (HR = 1.81; 1.11-2.95). Losing weight to a lower BMI category, however, was inversely associated with cancers of the corpus uteri (HR = 0.40; 0.23-0.69) and colon (HR = 0.69; 0.52-0.92). Our findings support avoiding weight gain and encouraging weight loss in middle adulthood.

Physical multimorbidity and cancer prevalence in the National Health and Nutrition Examination Survey

OBJECTIVES

As the US population ages, both cancer and multimorbidity become more common and pose challenges to the healthcare system. Limited studies have examined the association between multimorbidity and cancer prevalence in the US adult population. To help address this gap, we evaluated the associations between individual chronic conditions and all-site cancer, multimorbidity and all-site cancer, and multimorbidity and site-specific cancers.

STUDY DESIGN

This is a cross-sectional study.

METHODS

Data from 10,731 adults aged 20 years or older who participated in the 2013-2016 National Health and Nutrition Examination Survey were used in our study. Self-reported demographics, smoking status, sedentary behavior, body mass index, individual chronic conditions, multimorbidity status, cancer history, and cancer sites were assessed.

RESULTS

In our sample, the prevalence of having any type of cancer or multimorbidity was 9% (N = 861) and 38% (N = 4248), respectively. Respiratory conditions (multivariable-adjusted odds ratio [OR]: 1.3; 95% confidence interval [CI]: 1.1-1.6) and arthritis (multivariable-adjusted OR: 1.5; 95% CI: 1.2-1.8) were observed to be statistically significantly associated with having all-site cancer after adjusting for potential confounders. Having multimorbidity was also statistically significantly associated with having all-site cancer (multivariable-adjusted OR: 1.4; 95% CI: 1.2-1.7), cervical cancer (multivariable-adjusted OR: 2.6; 95% CI: 1.2-5.4), and bladder cancer (multivariable-adjusted OR: 2.8; 95% CI: 1.0-7.6).

CONCLUSIONS

Multimorbidity was associated with all-site cancer, cervical cancer, and bladder cancer. The present study provides new evidence of the potential relationships between multimorbidity and cancer. Future longitudinal studies are warranted to clarify the temporality and potential biological mechanisms of the associations between multimorbidity and cancer.

A prospective study of the associations among fine particulate matter, genetic variants, and the risk of colorectal cancer

BACKGROUND

Fine particulate matter (PM_2.5) is suspected to increase the risk of colorectal cancer, but the mechanism remains unknown. We aimed to investigate the association between PM_2.5 exposure, genetic variants and colorectal cancer risk in the Prostate, Lung, Colon and Ovarian (PLCO) Cancer Screening trial.

METHODS

We included a prospective cohort of 139,534 cancer-free individuals from 10 United States research centers with over ten years of follow-up. We used a Cox regression model to assess the association between PM_2.5 exposure and colorectal cancer incidence by calculating the hazard ratio (HR) and 95% confidence interval (CI) with adjustment for potential confounders. The polygenic risk score (PRS) and genome-wide interaction analysis (GWIA) were used to evaluate the multiplicative interaction between PM_2.5 exposure and genetic variants in regard to colorectal cancer risk.

RESULTS

After a median of 10.43 years of follow-up, 1,666 participants had been diagnosed with colorectal cancer. PM_2.5 exposure was significantly associated with an increased risk of colorectal cancer (HR = 1.27; 95% CI = 1.17-1.37 per 5 μg/m³ increase). Five independent susceptibility loci reached statistical significance at P < 1.22 × 10^-8 in the interaction analysis. Furthermore, a joint interaction was observed between PM_2.5 exposure and the PRS based on these five loci with colorectal cancer risk (P = 3.11 × 10^-29). The Gene Ontology analysis showed that the vascular endothelial growth factor (VEGF) receptor signaling pathway was involved in the biological process of colorectal cancer.

CONCLUSIONS

Our large-scale analysis has shown for the first time that long-term PM_2.5 exposure potential increases colorectal cancer risk, which might be modified by genetic variants.

The independent and combined effects of selected risk factors and Arg399Gln XRCC1 polymorphism in the risk of colorectal cancer among an Iranian population

Background: Several environmental and genetic factors have contributed to the development of colorectal cancer (CRC). We aimed to investigate the independent and combined effects of some selected risk factors and Arg399Gln XRCC1 polymorphism on CRC.

Methods: A total of 180 patients with CRC and 160 healthy individuals who were matched for sex, age, and place of residence (Northeast of Iran) participated in this case-control study. Before collecting blood samples and filling out questionnaires, a written consent form was obtained from all participants. Genotypes were determined by RFLP-PCR. The comparison of genotype and allele frequencies was performed using p value based on the results of chi-square test. The odds ratios (OR) and 95% confidence intervals (CI) were calculated by employing a logistic regression model. All statistical calculations were performed using SPSS. Each of the 2- sided p values less than 0.05 were considered statistically significant.

Results: The level of literacy, physical activity, consumption of vegetables and fruits, and tea intake of the patients were significantly lower than healthy individuals, but gastrointestinal disorders, family history of cancer, BMI, and fast food consumption were significantly higher in cases than in controls. No significant difference was observed between the 2 groups regarding smoking, opioid addiction, alcohol consumption, diet, fish consumption, and liquid intake, using the kitchen hood, diabetes, and cardiovascular disease. Arg/Gln + Gln/Gln and Arg/Gln genotypes were involved in increased CRC risk (The crude OR =1.781 with a 95% CI of 1.156-2.744 and OR = 1.690 with a 95% CI of 0.787-3.630). Also, Gln/Gln genotype was more frequent in CRC group than in control group. However, none of the risk factors interacted with polymorphism, and thus did not have an effect on CRC.

Conclusion: Some risk factors, such as reducing the consumption of vegetables and fruits or reducing physical activity as well as polymorphism of the XRCC1 Arg399Gln alone, increase the risk of CRC, but they do not interact with each other.

Latent Class Trajectory Modeling of Adult Body Mass Index and Risk of Obesity-Related Cancer: Findings from the Melbourne Collaborative Cohort Study

BACKGROUND

Obesity increases the risk of 13 cancer types. Given the long process of carcinogenesis, it is important to determine the impact of patterns of body mass over time.

METHODS

Using data from 30,377 participants in the Melbourne Collaborative Cohort Study, we identified body mass index (BMI) trajectories across adulthood and examined their association with the risk of obesity-related cancer. Participants completed interviews and questionnaires at baseline (1990-1994, age 40-69 years), follow-up 1 (1995-1998), and follow-up 2 (2003-2005). Body mass was recalled for age 18 to 21 years, measured at baseline, self-reported at follow-up 1, and measured at follow-up 2. Height was measured at baseline. Cancer diagnoses were ascertained from the Victorian Cancer Registry and the Australian Cancer Database. A latent class trajectory model was used to identify BMI trajectories that were not defined a priori. Cox regression was used to estimate HRs and 95% confidence intervals (CI) of obesity-related cancer risks by BMI trajectory.

RESULTS

Six distinct BMI trajectories were identified. Compared with people who maintained lower normal BMI, higher risks of developing obesity-related cancer were observed for participants who transitioned from normal to overweight (HR, 1.29; 95% CI, 1.13-1.47), normal to class I obesity (HR, 1.50; 95% CI, 1.28-1.75), or from overweight to class II obesity (HR, 1.66; 95% CI, 1.32-2.08).

CONCLUSIONS

Our findings suggest that maintaining a healthy BMI across the adult lifespan is important for cancer prevention.

IMPACT

Categorization of BMI by trajectory allowed us to identify specific risk groups to target with public health interventions.

ASSOCIATION BETWEEN DIABETICS AND INTESTINAL CANCER WITH THE RISK OF MUTATION IN CD38 GENE IN IRANIAN POPULATION

BACKGROUND

Intestinal cancer often occurs in type 2 diabetic patients. The concept of increasing insulin levels and insulin-like growth factor in the blood with type 2 diabetes are stimulated with the growth and depletion of cloned cell walls, and the continuation of this process leads to the cellular deformation. This is the evidence for intestinal cancer in type 2 diabetes in population.

OBJECTIVE

In this study, we aimed to find out the relationship between diabetics and intestinal cancer based on CD38 gene mutation.

METHODS

Samples were collected from 200 population including normal and case ones. PCR products related to rs 6449181 of CD38 gene was amplified with ARMS-PCR technique, and a 420-bp sharp banding was observed as well. According three ARMS-PCR techniques, three primers were designed by oligo7 software. Primers include F1, F2 and R (amplifying for normal, mutant and reverse primer respectively).

RESULTS

This band was observed using a primer F1 that carries the wild type nucleotide using a primer, and when it is used with the F2 primer, it brings the mutant primer to populations of patients with diabetes and diabetes-cancer. In addition, the clinical results including body mass index, blood glucose and insulin level were analyzed. The means ±SD and Tuckey's post hoc test were significant between the clinical characterization parameters between cases and healthy populations. The allelic gene frequencies and Hardy-Weinberg equilibrium between nucleotides were evaluated, and the significant level between the alleles and gene frequencies was observed.

CONCLUSION

In general, the current study found that there is a relationship between diabetes and intestinal cancer among the studied populations.

Relationship between prediagnostic body mass index trajectory and colorectal adenomas: an analysis of the PLCO cancer screening trial

Background

Studies on the relationship between lifetime body mass index (BMI) trajectory and colorectal premalignant precursor lesions are limited. This study aimed to assess the relationship between prediagnostic adulthood BMI trajectory and the risk of colorectal adenomas using data from the Prostate, Lung, Colorectal and Ovarian (PLCO) cancer screening trial.

Methods

In total, 39,824 participants in the intervention arm of the prospective PLCO cohort, who have undergone at least one colonoscopy or sigmoidoscopy examination with a confirmed diagnosis of colorectal adenomas, were enrolled and divided into four groups (underweight, normal weight, overweight, and obese) according to BMI during each age period. SAS Proc Traj was used to establish the BMI trajectory model. Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs).

Results

Compared with normal weight, overweight or obesity significantly increased colorectal adenomas risk in each age period after 30 years. Specifically, obesity in the 50s was most closely related to colorectal adenomas risk [HR: 1.32, 95% CI: (1.22, 1.43)]. BMI gain from the age of 40 to 50 [HR: 1.25, 95% CI: (1.11, 1.42)] showed the strongest correlation with an increased incidence of colorectal adenomas, followed by that from the age of 30 to 50 [HR: 1.19, 95% CI: (1.10, 1.29)], the age of 20 to 50 [HR: 1.16, 95% CI: (1.10, 1.24)], the age of 20 to 40 [HR: 1.14, 95% CI: (1.05, 1.23)], and the age of 20 to 30 [HR: 1.13, 95% CI: (1.02, 1.26)]. Additionally, compared with those who maintained normal weight throughout adulthood, those who progressed from normal weight to obesity [HR: 1.15, 95% CI: (1.06, 1.25)], or from overweight to obesity [HR: 1.33, 95% CI: (1.11, 1.61)], had a higher risk of colorectal adenomas.

Conclusions

Overweight and obesity increased the risk of colorectal adenomas, and this risk increased with advancing age.

Prediagnostic BMI and thyroid cancer incidence in the PLCO trial

Aim: To assess the correlation between prediagnostic BMI and thyroid cancer risk within the prostate, lung, colorectal and ovary (PLCO) trial. Methods: PLCO trial participants without a history of thyroid cancer before study enrollment who have complete information about prediagnostic BMI were included. Multivariable Cox regression analyses were conducted to assess the impact of prediagnostic BMI on thyroid cancer risk. Results: Higher BMI at the time of the study enrollment was associated with a higher thyroid cancer risk (hazard ratio: 1.046; p < 0.01). Furthermore, compared with a normal to normal prediagnostic BMI trajectory, both normal to overweight as well as normal to obese trajectories were associated with a higher thyroid cancer risk (p = 0.04 and p = 0.03, respectively). Conclusion: Higher BMI at the time of study entry as well as an increasing prediagnostic BMI trajectory are associated with a higher thyroid cancer risk.

Clinical stages of colorectal cancer diagnosed in obese and overweight individuals in the Polish Colonoscopy Screening Program

Background

Obesity is a known risk factor of colorectal cancer (CRC). However, precise interconnections between excessive body fat and CRC are still vague. Therefore, the aim of this study was to assess whether stage of CRC detected in overweight and obese individuals differs from individuals with normal body mass index (BMI). A secondary aim of this study was to elucidate whether overweight and obesity influence the overall survival in CRC.

Methods

This study was a cross-sectional analysis of 163,129 individuals who underwent screening colonoscopy performed on data from a prospectively maintained database of the Polish Colonoscopy Screening Program.

Results

Overweight and obese individuals present with a less advanced CRC in screening setting (p = 0.014). This trend is the most pronounced in males (p = 0.001). Univariable and multivariable analyses revealed that obesity was a negative predictor of detection of advanced CRC with odds ratio 0.72 (95% confidence interval 0.52-1.00; p = 0.047). Furthermore, overweight and obesity were not statistically significant predictors of risk of death (p = 0.614 and p = 0.446, respectively).

Conclusions

Obese screenees present with a less advanced disease in comparison to non-obese. Moreover, survival stratified by clinical stage seems to not be influenced by BMI category. Therefore, a higher proportion of early diagnosed cancers can potentially create a survival benefit in this group.