Risk Factor Profiles Differ for Cancers of Different Regions of the Colorectum

A comprehensive review of phytochemicals targeting macrophages for the regulation of colorectal cancer progression

BACKGROUND

Phytochemicals are natural compounds derived from plants, and are now at the forefront of anti-cancer research. Macrophage immunotherapy plays a crucial role in the treatment of colorectal cancer (CRC). In the context of colorectal cancer, which remains highly prevalent and difficult to treat, it is of research value to explore the potential mechanisms and efficacy of phytochemicals targeting macrophages for CRC treatment.

PURPOSE

The aim of this study was to gain insight into the role of phytochemical-macrophage interactions in regulating CRC and to provide a theoretical basis for the development of new therapeutic strategies in the future.

STUDY DESIGN

This review discusses the potential immune mechanisms of phytochemicals for the treatment of CRC by summarizing research of phytochemicals targeting macrophages.

METHODS

We reviewed the PubMed, EMBASE, Web of Science and CNKI databases from their initial establishment to July 2023 to classify and summaries phytochemicals according to their mechanism of action in targeting macrophages.

RESULTS

The results of the literature review suggest that phytochemicals interfere with CRC development by affecting macrophages through four main mechanisms. Firstly, they modulate the production of cytotoxic substances, such as NO and ROS, by macrophages to exert anticancer effects. Secondly, phytochemicals polarize macrophages towards the M1 phenotype, inhibit M2 polarisation and enhance the anti-tumour immune responses. Thirdly, they enhance the secretion of macrophage-derived cytokines and alter the tumour microenvironment, thereby inhibiting tumor growth. Finally, they activate the immune response by targeting macrophages, triggering the recruitment of other immune cells, thereby enhancing the immune killing effect and exerting anti-tumor effects. These findings highlight phytochemicals as potential therapeutic strategies to intervene in colorectal cancer development by modulating macrophage activity, providing a strong theoretical basis for future clinical applications.

CONCLUSION

Phytochemicals exhibit potential anti-tumour effects by modulating macrophage activity and intervening in the colorectal cancer microenvironment by multiple mechanisms.

The Cancer Spectrum Theory

SUMMARY

Biological characteristics of tumors are heterogeneous, forming spectra in terms of several factors such as age at onset, anatomic spatial localization, tumor subtyping, and the degree of tumor aggressiveness (encompassing a neoplastic property spectrum). Instead of blindly using dichotomized approaches, the application of the multicategorical and continuous analysis approaches to detailed cancer spectrum data can contribute to a better understanding of the etiology of cancer, ultimately leading to effective prevention and precision oncology. We provide examples of cancer spectra and emphasize the importance of integrating the cancer spectrum theory into large-scale population cancer research.

Sex differences in cancer incidence among solid organ transplant recipients

BACKGROUND

Males have 2-3-fold greater risk of cancer than females at most shared anatomic sites, possibly reflecting enhanced immune surveillance against cancer in females. We examined whether these sex differences remained among immunocompromised adults.

METHODS

Using the Transplant Cancer Match (TCM) study, we estimated the male-to-female incidence rate ratio in TCM (M:F IRRTransplant) for 15 cancer sites diagnosed between 1995 and 2017 using Poisson regression. Male to female IRRs in the general population (M:F IRRGP) were calculated using expected cancer counts from the Surveillance, Epidemiology, and End Results Program, standardized to the transplant population on age, race and ethnicity, and diagnosis year. Male to female IRRs were compared using a chi-square test.

RESULTS

Among 343 802 solid organ transplants, 211 206 (61.4%) were among men and 132 596 (38.6%) among women. An excess cancer incidence in males was seen in transplant recipients, but the sex difference was attenuated for cancers of the lip (M:F IRRTransplant: 1.81 vs M:F IRRGP: 3.96; P < .0001), stomach (1.51 vs 2.09; P = .002), colorectum (0.98 vs 1.43; P < .0001), liver (2.39 vs 3.44; P = .002), kidney (1.67 vs 2.24; P < .0001), bladder (2.02 vs 4.19; P < .0001), Kaposi sarcoma (1.79 vs 3.26; P = .0009), and non-Hodgkin lymphoma (1.34 vs 1.64; P < .0001). The M:F IRRTransplant was not statistically different from the M:F IRRGP for other cancer sites.

CONCLUSIONS

Although male solid organ transplant recipients have higher cancer incidence than female recipients, the attenuation in the male to female ratio for many cancers studied relative to the general population might suggest the importance of immunosurveillance, with some loss of advantage in female recipients due to immunosuppression after transplantation.

Carbohydrate quality, not quantity, linked to reduced colorectal cancer incidence and mortality in US populations: evidence from a prospective study

BACKGROUND

Carbohydrates have been implicated in colorectal cancer (CRC) risk, but the specific impact of carbohydrate quality and quantity on CRC susceptibility in US populations remains unclear.

METHODS

We followed 101,694 participants from Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial. The carbohydrate quality index (CQI) and low-carbohydrate diet score (LCDs) were used to evaluate the daily carbohydrate quality and quantity separately, where higher scores indicated greater adherence. Cox proportional hazards regression was used to compute HRs and 95% CIs for incident CRC and related death. Subgroup analyses were conducted to identify potential effect modifiers.

RESULTS

During follow-up, we documented 1085 incident cases of CRC, of whom 311 died from CRC. Individuals in the highest compared with the lowest quartiles of CQI had a lower CRC incidence (Q4 vs Q1: HR 0.80, 95% CI 0.67-0.96, Ptrend = 0.012) and mortality (Q4 vs Q1: HR 0.61, 95% CI 0.44-0.86, Ptrend = 0.004). The inverse association between CQI and CRC risk was observed for distal colon and rectum but not for proximal colon cancer. Regarding mortality, this association was only significant for rectum cancer. Subgroup analyses indicated this inverse association of CQI with CRC risk was only observed in participants with lower LCDs. No significant associations were found between LCDs and CRC incidence or mortality.

CONCLUSIONS

Our findings suggest focusing on higher quality, rather than restricting the quantity, of carbohydrate consumption may be an effective approach to reduce the risk of CRC in the US population, particularly for distal colon and rectal cancers.

Genome-wide polygenic risk scores for colorectal cancer have implications for risk-based screening

BACKGROUND

Hereditary factors, including single genetic variants and family history, can be used for targeting colorectal cancer (CRC) screening, but limited data exist on the impact of polygenic risk scores (PRS) on risk-based CRC screening.

METHODS

Using longitudinal health and genomics data on 453,733 Finnish individuals including 8801 CRC cases, we estimated the impact of a genome-wide CRC PRS on CRC screening initiation age through population-calibrated incidence estimation over the life course in men and women.

RESULTS

Compared to the cumulative incidence of CRC at age 60 in Finland (the current age for starting screening in Finland), a comparable cumulative incidence was reached 5 and 11 years earlier in persons with high PRS (80-99% and >99%, respectively), while those with a low PRS (< 20%) reached comparable incidence 7 years later. The PRS was associated with increased risk of post-colonoscopy CRC after negative colonoscopy (hazard ratio 1.76 per PRS SD, 95% CI 1.54-2.01). Moreover, the PRS predicted colorectal adenoma incidence and improved incident CRC risk prediction over non-genetic risk factors.

CONCLUSIONS

Our findings demonstrate that a CRC PRS can be used for risk stratification of CRC, with further research needed to optimally integrate the PRS into risk-based screening.

Long-term trends in the burden of colorectal cancer in Europe over three decades: a joinpoint regression and age-period-cohort analysis

Background

The burden of colorectal cancer (CRC) in Europe is at a high level, but the epidemiological features have not yet been systematically studied. This study aimed to provide a timely and reliable assessment of the burden and trends of CRC in Europe to provide a scientific basis for its prevention and treatment.

Methods

We analyzed data on CRC in 44 European countries between 1990 and 2019 from the Global Burden of Disease study (GBD) 2019. In addition, the joinpoint regression model was applied to reflect temporal trends. The age-period-cohort model was constructed to explore age, period, and birth cohort effects that influence the risk of morbidity and mortality.

Results

In Europe, new cases, disability-adjusted life years (DALYs) and deaths of CRC rose by 70.01%, 22.88% and 38.04% from 1990 to 2019, respectively. The age-standardized incidence rate (ASIR) has increased, while age-standardized DALY rate and age-standardized mortality rate (ASMR) have declined. We found that men experienced a significantly higher CRC burden than women. Age-period-cohort analysis showed that the risk of incidence and mortality increased with age and time; and it was lower in the later-born cohort than the earlier-born cohort.

Conclusion

ASIR for CRC in Europe generally trended upwards from 1990 to 2019, stabilizing in recent years but still at a high level. CRC burden varied considerably in different countries. There was a pronounced gender difference in CRC burden, and middle-aged and older men should be a priority population for CRC prevention and treatment.

Temporal trends in age- and stage-specific incidence of colorectal adenocarcinomas in Germany

BACKGROUND

A national colorectal cancer (CRC) screening programme was launched in 2002 in Germany. A comprehensive evaluation of the programme effectiveness using real-world data is still lacking. In addition, there are regional reports on increasing colorectal cancer incidence in younger populations. Therefore, we aimed to describe and compare the overall, age- and stage-specific incidence trends for colorectal, colon and rectal cancer.

METHODS

We used data from seven population-based cancer registries in Germany. We report absolute and relative changes in incidence rates between the early screening phase (2003-2005) and the most recent time period available (2015-2017), as well as annual percent changes. We analysed incidences according to tumour site (colorectum, colon, and rectum) and to six age groups (young adults: 15-34, 35-39, 40-49, screening-entitled/older adults: 50-54, 55-69 and 70 + years old).

RESULTS

In our sample of 271,011 colorectal adenocarcinomas, about two-thirds were located in the colon and 95% of them occurred in the age group 50+ (50-54: 5%, 55-69: 32.8%, 70+: 57.2%). For the time period 2003-2005 the age-specific incidence rates of individuals in the age group 55-69 were about 76/100,00 for colon and 54/100,000 for rectal cancer (age group 70 + colon: 179/100,000; rectum: 84/100,000). The incidence rates in young adults were less than 13% of that of individuals in the age group 55-69 (< 5% of individuals aged 70+; <33% of individuals aged 50-54). Over time, incidence decreased in individuals at the age of 55+, for all subsites considered as well as for early and late stage cancers (with few exceptions), while incidence of young adult CRC (both early and late stage) increased steepest in the youngest age groups. For late stage rectal cancer, a shift was observed in all age groups from UICC stage IV to stage III being the most frequent stage.

CONCLUSIONS

Six years after the introduction of the national colonoscopy screening program, late stage CRC incidence began to decline substantially in the screening-eligible age groups (55-69, 70+). It is likely that this decline and the increase in early stage CRC observed in younger age groups can be attributed to the program. Long lasting public awareness campaigns for CRC screening might have led to opportunistic screening in younger adults. Whether these benefits outweigh the possible harm of screening in younger age groups remains unclear.

Factors influencing advanced colorectal neoplasm anatomic site distribution in China: An epidemiological study based on colorectal cancer screening data

OBJECTIVE

Existing studies indicate that advanced colorectal neoplasms exhibit distinct clinical and biological traits based on anatomical sites. However, in China, especially for advanced colorectal neoplasms, there's limited information available on these traits. Our primary objective is to comprehensively study the characteristics of advanced colorectal neoplasm patients in different anatomical sites in China.

METHODS

We selected information from the colorectal cancer screening database in Tianjin, China, since 2010 as the study subject. We chose valid information from 3113 patients with comprehensive data and diagnosed advanced colorectal neoplasms (ANs) from a pool of 19,308 individuals to be included in the study. We then conducted further analysis to examine the correlation between these epidemiological data and tumor location.

RESULTS

Among the 3113 patients, neoplasms in the left side of the colon accounted for the largest proportion, while neoplasms in the right side of the colon had the smallest proportion, followed by rectal neoplasms. The highest proportion of advanced colorectal neoplasms was found among men. In the age group of 39-49 years old, the proportion of left late-stage advanced colon neoplasms was equal to that of right late-stage advanced colon neoplasms, while late-stage advanced rectal neoplasms increased with age. Smoking, drinking, and a history of colon cancer in first-degree relatives showed statistically significant associations with the location distribution of advanced colorectal neoplasms. A history of appendicitis, appendectomy, cholecystitis, or cholecystectomy did not significantly affect the location distribution of advanced colorectal neoplasms. However, among patients with such histories, there was a statistically significant relationship between advanced colon neoplasms on the right and those on the left and in the rectum. Similar results were observed for BMI.

CONCLUSION

Our research findings demonstrate that advanced colorectal neoplasms display unique epidemiological characteristics depending on their anatomical locations, and these distinctions deviate from those observed in Western populations. These insights contribute to a more comprehensive understanding of the topic and offer valuable guidance for future research in China. We advocate for further investigations centered on the anatomical location of colorectal neoplasms to enhance the precision of colorectal cancer (CRC) screening and treatment.

The association between pro-vegetarian dietary pattern and risk of colorectal cancer: a matched case-control study

BACKGROUND

Few studies assess the link between plant-based diets and colorectal cancer (CRC) incidence. To our knowledge, no study has examined the association between pro-vegetarian dietary pattern (PDP) and CRC globally or among Iranians. Therefore, the objective of our matched case-control study was to evaluate the association between PDP and CRC in the Iranian population.

METHODS

The present research was a hospital-based case (n = 71)-control (n = 142) study conducted in the same hospitals in Tehran, Iran. This study used a reliable and valid semi-quantitative food frequency questionnaire to evaluate the participants' dietary intake. According to the residual method, the selected plant and animal foods have been adjusted in the total energy intake to calculate the PDP index. Odds ratios (ORs) and 95% confidence intervals (CIs) adjusted for confounding variables were also expressed using logistic regression by SPSS software.

RESULTS

In the crude and adjusted models, we observed that the odds of CRC decreased significantly in the 3rd and last quartile of PDP compared to the 1st quartile (Q) (Crude model: Q3: OR = 0.36, 95% CI: 0.17 - 0.79, P-value = 0.011 and Q4: OR = 0.33, 95% CI: 0.14 - 0.79, P-value = 0.012 - Adjusted model: Q3: OR = 0.41, 95% CI: 0.18 - 0.94, P-value = 0.035 and Q4: OR = 0.35, 95% CI: 0.14 - 0.87, P-value = 0.025).

CONCLUSIONS

Based on the results of the present case-control study in the Iranian population, it was concluded that PDP, which involves consuming vegetables, fruits, cereals, dairy products, and low meat consumption, reduces the odds of CRC. In conclusion, adherence to PDP is associated with a decreased odds of CRC.

Inflammatory Bowel Disease and Risk of Colorectal Polyps: A Nationwide Population-Based Cohort Study From Sweden

BACKGROUND

Inflammatory bowel disease [IBD] has been linked to an increased risk of colorectal neoplasia. However, the types and risks of specific polyp types in IBD are less clear.

METHODS

We identified 41 880 individuals with IBD (Crohn's disease [CD: n = 12 850]; ulcerative colitis [UC]: n = 29 030]) from Sweden matched with 41 880 reference individuals. Using Cox regression, we calculated adjusted hazard ratios [aHRs] for neoplastic colorectal polyps [tubular, serrated/sessile, advanced and villous] defined by histopathology codes.

RESULTS

During follow-up, 1648 [3.9%] IBD patients and 1143 [2.7%] reference individuals had an incident neoplastic colorectal polyp, corresponding to an incidence rate of 46.1 and 34.2 per 10 000 person-years, respectively. This correlated to an aHR of 1.23 (95% confidence interval [CI] 1.12-1.35) with the highest HRs seen for sessile serrated polyps [8.50, 95% CI 1.10-65.90] and traditional serrated adenomas [1.72, 95% CI 1.02-2.91]. aHRs for colorectal polyps were particularly elevated in those diagnosed with IBD at a young age and at 10 years after diagnosis. Both absolute and relative risks of colorectal polyps were higher in UC than in CD [aHRs 1.31 vs 1.06, respectively], with a 20-year cumulative risk difference of 4.4% in UC and 1.5% in CD, corresponding to one extra polyp in 23 patients with UC and one in 67 CD patients during the first 20 years after IBD diagnosis.

CONCLUSIONS

In this nationwide population-based study, there was an increased risk of neoplastic colorectal polyps in IBD patients. Colonoscopic surveillance in IBD appears important, especially in UC and after 10 years of disease.

Plant-based dietary patterns, genetic predisposition and risk of colorectal cancer: a prospective study from the UK Biobank

BACKGROUND

Plant-based dietary patterns may affect colorectal cancer (CRC) related outcomes, while risks differ in the quality of plant foods. We aimed to examine the association of plant-based diet quality with risks of CRC incidence and mortality and whether this association was modified by genetic risk.

METHODS

This prospective cohort study included 186,675 participants free of cancer when the last dietary recall was completed. We calculated three plant-based diet indices (PDIs), i.e., the overall plant-based diet index (PDI), the healthful plant-based diet index (hPDI), and the unhealthful plant-based diet index (uPDI) representing adherence to plant-based diets with diverse quality. Genetic risk was characterized using a weighted polygenic risk score (PRS), capturing overall risk variants associated with CRC. Hazard ratios (HR) and 95% confidential intervals (CI) were estimated by the cause-specific Cox proportional hazards model.

RESULTS

Over a follow-up of 9.5 years, 2163 cases and 466 deaths from CRC were documented. The HR of CRC incidence was 0.88 (95% CI, 0.81-0.96) and 0.91 (95% CI, 0.84-0.99) per 10-score increase in PDI and hPDI, respectively. Compared to the lowest quartile, PDI, hPDI, and uPDI in the highest quartile were associated with a 13% decrease, a 15% decrease, and a 14% increase in risk of incident CRC, respectively. We found a joint association of genetic risk and PDIs with incident CRC, with the highest hazard observed in those carrying higher PRS and adhering to lower-quality PDIs. The inverse association of PDI and hPDI with CRC mortality was pronounced in males.

CONCLUSIONS

Our results suggested that better adherence to overall and healthful plant-based diets was associated with a lower risk of CRC, whereas an unhealthful plant-based diet was associated with a higher CRC risk. Consumption of a higher-quality plant-based diet combined with decreased genetic risk conferred less susceptibility to CRC. Our findings highlighted the importance of food quality when adhering to a plant-based dietary pattern for CRC prevention in the general population.

Early onset colorectal cancer in Canterbury, New Zealand

BACKGROUND

The overall incidence of colorectal cancer is decreasing in much of the world, yet the incidence in those under 50 years of age is increasing (early onset colorectal cancer (EOCRC)). The reasons for this are unclear. This study was undertaken to describe the clinical, pathological and familial characteristics of patients with EOCRC and their oncological outcomes and compare this with previously published data on late onset colorectal cancer (LOCRC).

METHODS

A retrospective review of all patients diagnosed with EOCRC in Canterbury between 2010 and 2017 was conducted. Data was collected on demographics, family history, treatment, and oncologic outcomes. Kaplan-Meier survival curves were calculated to assess overall survival based on disease stage.

RESULTS

During the study period (2010-2017) there were 3340 colorectal cancers diagnosed in Canterbury, of which 201 (6%) were in patients under 50 years (range: 17-49). Of these, 87 (43.3%) were female and 125 (62.2%) were aged between 40 and 49 years. 28 (13.9%) were associated with hereditary conditions. Of the 201 patients, 139 (69.2%) had rectal or left-sided cancers. 142 (70.6%) patients presented with either stage 3 or 4 disease and the 5-year overall survival by stage was 79.1% and 14.4%, respectively.

CONCLUSION

EOCRC is increasing and usually presents as distal left sided cancers, and often at an advanced stage. They do not appear to have the common risk factors of family history or inherited pre-disposition for colorectal cancer. Planning by healthcare providers for this epidemiological change is imperative in investigating symptomatic patients under 50 and optimizing early detection and prevention.

Molecular Characteristics of Early-Onset Colorectal Cancer According to Detailed Anatomical Locations: Comparison With Later-Onset Cases

INTRODUCTION

Early-onset colorectal cancer diagnosed before the age of 50 years has been increasing. Likely reflecting the pathogenic role of the intestinal microbiome, which gradually changes across the entire colorectal length, the prevalence of certain tumor molecular characteristics gradually changes along colorectal subsites. Understanding how colorectal tumor molecular features differ by age and tumor location is important in personalized patient management.

METHODS

Using 14,004 cases with colorectal cancer including 3,089 early-onset cases, we examined microsatellite instability (MSI), CpG island methylator phenotype (CIMP), and KRAS and BRAF mutations in carcinomas of the cecum, ascending colon, transverse colon, descending colon, sigmoid colon, and rectum and compared early-onset cases with later-onset cases.

RESULTS

The proportions of MSI-high, CIMP-high, and BRAF -mutated early-onset tumors were lowest in the rectum (8.8%, 3.4%, and 3.5%, respectively) and highest in the ascending colon (46% MSI-high; 15% CIMP-high) or transverse colon (8.6% BRAF -mutated) (all Ptrend <0.001 across the rectum to ascending colon). Compared with later-onset tumors, early-onset tumors showed a higher prevalence of MSI-high status and a lower prevalence of CIMP-high status and BRAF mutations in most subsites. KRAS mutation prevalence was higher in the cecum compared with that in the other subsites in both early-onset and later-onset tumors ( P < 0.001). Notably, later-onset MSI-high tumors showed a continuous decrease in KRAS mutation prevalence from the rectum (36%) to ascending colon (9%; Ptrend <0.001), followed by an increase in the cecum (14%), while early-onset MSI-high cancers showed no such trend.

DISCUSSION

Our findings support biogeographical and pathogenic heterogeneity of colorectal carcinomas in different colorectal subsites and age groups.

Epidemiology of overall and early-onset serrated polyps versus conventional adenomas in a colonoscopy screening cohort

Serrated polyps (SPs) are precursors to one-third of colorectal cancers (CRCs), with histological subtypes: hyperplastic polyps (HPs), sessile serrated lesions (SSLs) and traditional serrated adenomas (TSAs). The incidence of early-onset CRC before the age of 50 is increasing, with limited understanding of SPs in younger cohorts. Using a large colonoscopy-based cohort, we characterized epidemiologic profiles of SP subtypes, compared to conventional adenomas, with secondary analysis on early-onset polyps. Ninety-four thousand four hundred and twenty-seven patients underwent screening colonoscopies between 2010 and 2018. Demographic, endoscopic and histopathologic characteristics of each polyp subtype were described. High-risk polyps included SSLs ≥10 mm/with dysplasia and conventional adenomas ≥10 mm/with tubulovillous/villous histology/high-grade dysplasia. We examined polyp prevalence with age and compared early- (age < 50) and late-onset polyps (age ≥ 50). Eighteen thousand one hundred and twenty-five patients had SPs (4357 SSLs, 15 415 HPs, 120 TSAs) and 26 699 had conventional adenomas. High-risk SSLs were enriched in the ascending colon (44.1% vs 2.6-35.8% for other locations; P < .003). Early- and late-onset SPs had similar subsite distribution. Early-onset conventional adenomas were more enriched in the distal colon/rectum (51.8% vs 43.4%, P < .001). Multiple conventional adenomas were more represented in late-onset groups (40.8% vs 33.8%, P < .001), with no difference in SSLs. The prevalence of conventional adenomas/high-risk conventional adenomas increased continuously with age, whereas the prevalence of SSLs/high-risk SSLs was stable from age 40 years onwards. A higher proportion of women were diagnosed with early-onset than late-onset SSLs (62.9% vs 57.6%, P = .03). Conventional adenomas, SSLs, early- and late-onset polyps have distinct epidemiology. The findings have implications for improved colonoscopy screening and surveillance and understanding the etiologic heterogeneity of CRC.

Research progress of traditional Chinese medicine as sensitizer in reversing chemoresistance of colorectal cancer

In recent years, the incidences and mortalities from colorectal cancer (CRC) have been increasing; therefore, there is an urgent need to discover newer drugs that enhance drug sensitivity and reverse drug tolerance in CRC treatment. With this view, the current study focuses on understanding the mechanism of CRC chemoresistance to the drug as well as exploring the potential of different traditional Chinese medicine (TCM) in restoring the sensitivity of CRC to chemotherapeutic drugs. Moreover, the mechanism involved in restoring sensitivity, such as by acting on the target of traditional chemical drugs, assisting drug activation, increasing intracellular accumulation of anticancer drugs, improving tumor microenvironment, relieving immunosuppression, and erasing reversible modification like methylation, have been thoroughly discussed. Furthermore, the effect of TCM along with anticancer drugs in reducing toxicity, increasing efficiency, mediating new ways of cell death, and effectively blocking the drug resistance mechanism has been studied. We aimed to explore the potential of TCM as a sensitizer of anti-CRC drugs for the development of a new natural, less-toxic, and highly effective sensitizer to CRC chemoresistance.

The comparison of risk factors for colorectal neoplasms at different anatomical sites

AIM

Both the clinical manifestation and molecular characteristics of colorectal cancer (CRC) vary according to the anatomical site. We explored the risk factors for four groups of colorectal neoplasms (CRN) at different anatomical sites.

METHODS

We extracted data from the database of Tianjin Colorectal Cancer Screening Program from 2010 to 2020. According to the CRN anatomical sites, patients were divided into four groups: the proximal colon group, the distal colon group, the rectum group, and the multiple colorectal sites. Binary logistic regression analysis was used to explore the differences in risk factors of CRN at different anatomical sites.

RESULTS

The numbers of patients with CRN in the proximal colon, distal colon, rectum, and multiple colorectal sites were 4023, 6920, 3657, and 7938, respectively. Male sex was associated with a higher risk from the proximal colon to the rectum. Advanced age and obesity were also significantly associated with overall colorectal CRN risk, but there were some differences between men and women. Smoking was associated with CRN risk only in the distal colon and rectum in both men and women. Frequent alcohol consumption and family history of CRC in first-degree relatives (FDRs) were associated with the risk of multisite colorectal CRN only in males.

CONCLUSIONS

We observed differences in advanced age, obesity, smoking, alcohol consumption, and family history of colorectal cancer at different anatomical sites of colorectal neoplasms. These factors vary by gender.

Awareness of the Link Between the Consumption of Ultra-Processed Food and Colorectal Cancer Risk in Saudi Arabia

Introduction Cancer is a group of diseases with uncontrollable growth of abnormal cells. Colorectal cancer (CRC) is one of the most common cancers. Increased intake of animal-source foods, sedentary lifestyle, decreased physical activity, and increased prevalence of excess body weight are independently associated with CRC risk. Additional risk factors include heavy alcohol consumption, cigarette smoking, and consumption of red or processed meat. Ultra-processed food (UPF) is made utilizing multiple components and a number of procedures. Soft drinks and salty or sugary snacks typically contain a lot of added sugar, fats, and processed carbohydrates, which negatively affect the balance of the gut bacteria, nutrients, and bioactive substances that are necessary for the prevention of CRC. The aim of this study is to assess the awareness of the general population in Saudi Arabia toward the relationship between UPF and CRC. Methods A cross-sectional questionnaire-based study was conducted in Saudi Arabia between June and December, 2022. Result The study involved 802 participants, of which 84% consumed UPF and 71% were aware of the link between UPF and CRC. Only 18.3% were familiar with the particular type of UPF and only 29.4% knew how to prepare them. The prevalence of participants who were aware of the link between UPF and CRC was significantly more among the older age groups, people living in the Eastern Region, and those who knew how to manufacture UPF, while the prevalence of awareness was significantly less among those who regularly consumed UPF. Conclusion The study showed that a significant portion of subjects regularly ate UPF, and only a few were aware of its link to CRC. This highlights the need for greater awareness of the fundamentals of UPF and its impact on health. Governmental organizations should develop a strategy to raise public awareness of excessive UPF use.

The Cancer Genome Atlas (TCGA) based m6A methylation-related genes predict prognosis in rectosigmoid cancer

N6-methyladenosine (m6A) methylation plays an important role in the occurrence and development of tumors. This study aimed to explore the effects of m6A methylation regulatory genes on rectosigmoid cancer (RSC). RNA-seq data and related clinical information in The Cancer Genome Atlas database were analyzed. The Wilcoxon test was used to analyze the different expression levels of m6A methylation regulatory genes between the tumor and normal samples. Least absolute shrinkage and selection operator Cox regression analysis was used to construct a risk prognosis model between the m6A methylation regulatory genes and RSC. The median risk score was used to classify RSC patients into high and low-risk groups. Kaplan-Meier survival analysis and receiver operating characteristic curves were used to evaluate the sensitivity and specificity of the prediction model. The expression of m6A methylation regulation genes was different between the tumor and normal samples, 6 genes were overexpressed in tumor and 2 genes were down-regulated. Four m6A methylation regulatory genes, YTHDF3, KIAA1429, ALKBH5 and METTL3, were screened by least absolute shrinkage and selection operator Cox regression analysis. The overall survival of high-risk group was significantly lower than that of low-risk group (P = 4.681 × 10-4). The area under the curve value in the receiver operating characteristic curve was 0.935, indicating that the prediction model was effective. Univariate and multivariate Cox regression were used to test the effectiveness of the model. m6A methylation regulators YTHDF3, KIAA1429, ALKBH5, and METTL3 can be used to construct predictive models to predict overall survival in different clinical subgroups of RSC patients.

Pulsatilla Decoction Combined with 5-Fluorouracil Triggers Immunogenic Cell Death in Colorectal Cancer Cells

Background: Our research is designed to explore the role of 5-FU and Pulsatilla decoction (PD) through modulation of Immunogenic cell death (ICD) for the co-treatment of Colorectal cancer (CRC). Materials and Methods: Cell viability was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazol-3-ium bromide (MTT) assays. Cell apoptosis was assessed using flow cytometry. Phosphorylation of STAT3 and expression of Mcl-1 and Bcl-xl were measured by Western blot assays. The levels of ATP and HMGB1 in the supernatants of the culture medium were analyzed by ATP assays and the HMGB1 enzyme linked immunosorbent assay kit. The cell surface levels of CRT were measured by immunofluorescence assays. The tumor growth was analyzed in mice. Results: PD increased 5-FU-induced ICD in CRC cells, as demonstrated by the extracellular levels of adenosine triphosphate (ATP) and high-mobility group box 1 (HMGB1), and the surface levels of calreticulin (CRT). Our mechanism study showed that PD promoted 5-FU-induced ICD by inactivating signal transducer and activator of transcription 3 (STAT3). Furthermore, the co-treatment of 5-FU and PD further promoted 5-FU-induced CRT expression and T cell infiltration in vivo. Tumorigenicity analysis revealed that 5-FU combined with PD notably reduced tumor growth. Conclusion: This study indicated that PD enhances 5-FU-induced ICD and anti-tumor effect in CRC by inactivating STAT3. The combined application of 5-FU with PD may improve the anti-tumor activity of 5-FU in CRC.

Plant-based dietary patterns defined by a priori indices and colorectal cancer risk by sex and race/ethnicity: the Multiethnic Cohort Study

BACKGROUND

Plant-based diets assessed by a priori indices are associated with health outcomes. This study investigated the associations between pre-defined indices of plant-based diets and risk of colorectal cancer (CRC) and evaluated whether the association varies by sex, race and ethnicity, and anatomic subsite of tumors.

METHODS

A total of 79,952 men and 93,475 women who participated in the Multiethnic Cohort Study were included. Primary outcome was incidence of invasive CRC. Cox models were used to estimate the risk of CRC across quintiles of three plant-based diet scores: overall plant-based diet index (PDI), healthful plant-based diet index (hPDI), and unhealthful plant-based diet index (uPDI).

RESULTS

During a mean follow-up of 19.2 years, 4976 incident CRC were identified. Among men, multivariable-adjusted HR (95% CI) for the highest vs. lowest quintiles was 0.77 (0.67-0.88) for PDI, and 0.80 (0.70-0.91) for hPDI, while no significant association was found for uPDI among men and for all indices among women. In men, the inverse association for PDI was stronger in Japanese American, Native Hawaiian, and White groups than African American or Latino group (P for heterogeneity = 0.01) and for left colon and rectal tumors than right tumors (P for heterogeneity = 0.005), whereas the decreased risk with hPDI was found consistently across racial and ethnic groups and subsites.

CONCLUSIONS

Greater adherence to plant-based diets rich in healthy plant foods and low in less healthy plant foods is associated with a reduced risk of CRC in men, but not in women. The strength of the association among men may vary by race and ethnicity and anatomic subsite of tumors.

Adherence to a healthy lifestyle in relation to colorectal cancer incidence and all-cause mortality after endoscopic polypectomy: A prospective study in three U.S. cohorts

It remains unknown whether maintenance of a healthy lifestyle after endoscopic polypectomy could still confer benefit for colorectal cancer (CRC) incidence and mortality. In this study, we defined a healthy lifestyle score based on body mass index, smoking, physical activity, alcohol consumption and diet (range, 0-5). We used Cox proportional hazards regression to estimate the hazard ratios (HRs) for the associations of healthy lifestyle score and individual lifestyle factors with CRC incidence and all-cause mortality. During a median of 10 years of follow-up of 24 668 participants who underwent endoscopic polypectomy, we documented 161 CRC cases and 4857 all-cause deaths. A higher healthy lifestyle score after endoscopic polypectomy was associated with lower risk of CRC and all-cause mortality. Compared with individuals with 0 to 1 healthy lifestyle factors, those with 2, 3 and 4 to 5 healthy lifestyle factors had a HR for CRC risk of 0.86 (95% confidence interval [CI], 0.60-1.24), 0.73 (95% CI, 0.47-1.14) and 0.52 (95% CI, 0.27-1.01), respectively (Ptrend  = .03). The corresponding HR (95% CI) for all-cause mortality was 0.83 (95% CI, 0.76-0.90), 0.63 (95% CI, 0.56-0.70) and 0.56 (95% CI, 0.48-0.65), respectively (Ptrend  < .0001). In the joint analysis of pre- and postpolypectomy periods, patients with a healthy postpolypectomy lifestyle had a lower incidence of CRC regardless of their prepolypectomy exposure, whereas those with a healthy lifestyle in both periods had a lower mortality than those with an unhealthy lifestyle in either period. In conclusion, adherence to a healthy lifestyle after polypectomy may confer significant benefit for CRC prevention and reduction in all-cause mortality.

NAP1L1 promotes the growth of colon cancer by activating HDGF/DDX5

Colon cancer is a common malignant tumor. However, its pathogenesis still needs further study. In this study, we explored the role of nucleosome assembly protein 1-like 1 (NAP1L1) in colon cancer and its underlying mechanism. Based on analysis of The Cancer Genome Atlas data, we found that NAP1L1 is augmented in colorectal cancer, and the elevated NAP1L1 expression is associated with a poor prognosis in patients with colon cancer. Immunohistochemistry staining results showed that upregulated NAP1L1 protein level is an unfavorable factor that stimulates colon cancer progression. To further investigate the role of NAP1L1 in colon cancer, we established a colon cancer cell line with NAP1L1 knockdown, and found that repressing NAP1L1 expression in colon cancer cells markedly reduces cell proliferation in vivo and in vitro by MTT assay, colony formation, EdU incorporation, and subcutaneous tumorigenesis in nude mice. Furthermore, we found that NAP1L1 binds to HDGF, recruits DDX5, and induces β-catenin/CCND1 signaling, which promotes colon cancer cell proliferation. Finally, transfection with HDGF or DDX5restores cell growth in NAP1L1-knockdown colon cancer cells by upregulating DDX5/β-catenin/CCND1 signaling. Our study demonstrates that NAP1L1 functions as a potential oncogene that promotes colon cancer tumorigenesis by binding to HDGF, which stimulates DDX5/β-catenin/CCND1 signaling.

Association Between Metabolic Syndrome and the Risk of Colorectal Cancer Diagnosed Before Age 50 Years According to Tumor Location

BACKGROUND & AIMS

The increasing prevalence of obesity at younger ages is concurrent with an increased earlier-onset colorectal cancer (CRC) (before age 50 years) incidence, particularly left-sided colon cancer. We investigated whether obesity and metabolic syndrome (MetS) are associated with increased earlier-onset CRC risk according to tumor location.

METHODS

Our nationwide population-based cohort study enrolled 9,774,081 individuals who underwent health checkups under the Korean National Health Insurance Service from 2009 to 2010, with follow-up until 2019. We collected data on age, sex, lifestyle factors, body mass index (BMI), waist circumference (WC), blood pressure, and laboratory findings. A multivariate Cox proportional hazards regression analysis was performed.

RESULTS

A total of 8320 earlier-onset and 57,257 later-onset CRC cases developed during follow-up. MetS was associated with increased earlier-onset CRC (adjusted hazard ratio, 1.20; 95% CI, 1.14-1.27), similar to later-onset CRC (adjusted hazard ratio, 1.19; 95% CI, 1.17-1.21). The adjusted hazard ratios for earlier-onset CRC with 1, 2, 3, 4, and 5 MetS components were 1.07 (95% CI, 1.01-1.13), 1.13 (95% CI, 1.06-1.21), 1.25 (95% CI, 1.16-1.35), 1.27 (95% CI, 1.15-1.41), and 1.50 (95% CI, 1.26-1.79), respectively (P for trend < .0001). We found that higher body mass index and larger waist circumference were significantly associated with increased earlier-onset CRC (P for trend < .0001). These dose-response associations were significant in distal colon and rectal cancers, although not in proximal colon cancers.

CONCLUSIONS

MetS and obesity are positively associated with CRC before age 50 years with a similar magnitude of association as people diagnosed after age 50 years. Thus, people younger than 50 years with MetS require effective preventive interventions to help reduce CRC risk.

Association of ultra-processed food consumption with colorectal cancer risk among men and women: results from three prospective US cohort studies

OBJECTIVE

To examine the association between consumption of ultra-processed foods and risk of colorectal cancer among men and women from three large prospective cohorts.

DESIGN

Prospective cohort study with dietary intake assessed every four years using food frequency questionnaires.

SETTING

Three large US cohorts.

PARTICIPANTS

Men (n= 46 341) from the Health Professionals Follow-up Study (1986-2014) and women (n=159 907) from the Nurses' Health Study (1986-2014; n=67 425) and the Nurses' Health Study II (1991-2015; n=92 482) with valid dietary intake measurement and no cancer diagnosis at baseline.

MAIN OUTCOME MEASURE

Association between ultra-processed food consumption and risk of colorectal cancer, estimated using time varying Cox proportional hazards regression models adjusted for potential confounding factors.

RESULTS

3216 cases of colorectal cancer (men, n=1294; women, n=1922) were documented during the 24-28 years of follow-up. Compared with those in the lowest fifth of ultra-processed food consumption, men in the highest fifth of consumption had a 29% higher risk of developing colorectal cancer (hazard ratio for highest versus lowest fifth 1.29, 95% confidence interval 1.08 to 1.53; P for trend=0.01), and the positive association was limited to distal colon cancer (72% increased risk; hazard ratio 1.72, 1.24 to 2.37; P for trend<0.001). These associations remained significant after further adjustment for body mass index or indicators of nutritional quality of the diet (that is, western dietary pattern or dietary quality score). No association was observed between overall ultra-processed food consumption and risk of colorectal cancer among women. Among subgroups of ultra-processed foods, higher consumption of meat/poultry/seafood based ready-to-eat products (hazard ratio for highest versus lowest fifth 1.44, 1.20 to 1.73; P for trend<0.001) and sugar sweetened beverages (1.21, 1.01 to 1.44; P for trend=0.013) among men and ready-to-eat/heat mixed dishes among women (1.17, 1.01 to 1.36; P for trend=0.02) was associated with increased risk of colorectal cancer; yogurt and dairy based desserts were negatively associated with the risk of colorectal cancer among women (hazard ratio 0.83, 0.71 to 0.97; P for trend=0.002).

CONCLUSIONS

In the three large prospective cohorts, high consumption of total ultra-processed foods in men and certain subgroups of ultra-processed foods in men and women was associated with an increased risk of colorectal cancer. Further studies are needed to better understand the potential attributes of ultra-processed foods that contribute to colorectal carcinogenesis.

Anatomic location of colorectal cancer presents a new paradigm for its prognosis in African American patients

Among all racial groups in the U.S., African Americans (AA) have the highest incidence of and mortality from colorectal cancer (CRC). Although socioeconomic factors, as the major contributors to racial disparity of CRC, have been widely investigated, there is a dearth of information germane to understanding its biological basis. To better elucidate the clinicopathologic features we extracted demographic, clinical, pathologic and molecular features of 500 consecutive cases of CRC diagnosed at our institution which has an AA-predominant patient population (75% of all patients). We compared data from our AA patients with those of white patients both from our institution and from SEER and the published literature for meaningful comparison. AA patients were more likely to be at an advanced disease stage (25.9% vs. 20.8%, p = 0.041), have low grade tumors (89.2% vs. 77.5%, p<0.001) in cecum (18.7% vs. 16.2%, p<0.001) and <60-years-old than white patients (31.8% vs. 26.3%, p = 0.015). The frequency of KRAS mutation was higher in AA patients than in white patients (56.8% vs. 20.7%, p<0.001). Amongst subtypes of KRAS tested in CRC, codon 12 mutation is more common in AA than white patients (85.2% vs. 68.9%, p = 0.020). Compared with other racial groups, we found AA patients to have worse disease-free survival (HR = 3.682, p = 0.035). Also, AA patients with CRC in distal (sigmoid and rectum) or proximal (cecum) colon have worse overall survival than those with CRC in middle colon (HR = 2.926, p = 0.014), a finding not observed in white patients. In both racial groups, advanced stage, perforation, and hypertension were independent prognostic factors for overall survival (p<0.05). Similarly, low body-mass index at presentation, mucinous adenocarcinoma, lymphovascular invasion, perineural invasion and KRAS mutations were independent factors significantly associated with poor disease-free survival. Collectively, our data provide new insights into the roles of clinicopathologic features, especially anatomic distribution, in predicting outcomes of CRC in AA population.

Sugar-sweetened beverage and sugar consumption and colorectal cancer incidence and mortality according to anatomic subsite

BACKGROUND

Recent preclinical research strongly suggests that dietary sugars can enhance colorectal tumorigenesis by direct action, particularly in the proximal colon that unabsorbed fructose reaches.

OBJECTIVES

We aimed to examine long-term consumption of sugar-sweetened beverages (SSBs) and total fructose in relation to incidence and mortality of colorectal cancer (CRC) by anatomic subsite.

METHODS

We followed 121,111 participants from 2 prospective US cohort studies, the Nurses' Health Study (1984-2014) and Health Professionals Follow-Up Study (1986-2014), for incident CRC and related death. Cox proportional hazards regression was used to compute HRs and 95% CIs.

RESULTS

During follow-up, we documented 2733 incident cases of CRC with a known anatomic location, of whom 901 died from CRC. Positive associations of SSB and total fructose intakes with cancer incidence and mortality were observed in the proximal colon but not in the distal colon or rectum (Pheterogeneity ≤ 0.03). SSB consumption was associated with a statistically significant increase in the incidence of proximal colon cancer (HR per 1-serving/d increment: 1.18; 95% CI: 1.03, 1.34; Ptrend = 0.02) and a more pronounced elevation in the mortality of proximal colon cancer (HR: 1.39; 95% CI: 1.13, 1.72; Ptrend = 0.002). Similarly, total fructose intake was associated with increased incidence and mortality of proximal colon cancer (HRs per 25-g/d increment: 1.18; 95% CI: 1.03, 1.35; and 1.42; 95% CI: 1.12, 1.79, respectively). Moreover, SSB and total fructose intakes during the most recent 10 y, rather than those from a more distant period, were associated with increased incidence of proximal colon cancer.

CONCLUSIONS

SSB and total fructose consumption were associated with increased incidence and mortality of proximal colon cancer, particularly during later stages of tumorigenesis.

Associations Between Glycemic Traits and Colorectal Cancer: A Mendelian Randomization Analysis

BACKGROUND

Glycemic traits-such as hyperinsulinemia, hyperglycemia, and type 2 diabetes-have been associated with higher colorectal cancer risk in observational studies; however, causality of these associations is uncertain. We used Mendelian randomization (MR) to estimate the causal effects of fasting insulin, 2-hour glucose, fasting glucose, glycated hemoglobin (HbA1c), and type 2 diabetes with colorectal cancer.

METHODS

Genome-wide association study summary data were used to identify genetic variants associated with circulating levels of fasting insulin (n = 34), 2-hour glucose (n = 13), fasting glucose (n = 70), HbA1c (n = 221), and type 2 diabetes (n = 268). Using 2-sample MR, we examined these variants in relation to colorectal cancer risk (48 214 case patient and 64 159 control patients).

RESULTS

In inverse-variance models, higher fasting insulin levels increased colorectal cancer risk (odds ratio [OR] per 1-SD = 1.65, 95% confidence interval [CI] = 1.15 to 2.36). We found no evidence of any effect of 2-hour glucose (OR per 1-SD = 1.02, 95% CI = 0.86 to 1.21) or fasting glucose (OR per 1-SD = 1.04, 95% CI = 0.88 to 1.23) concentrations on colorectal cancer risk. Genetic liability to type 2 diabetes (OR per 1-unit increase in log odds = 1.04, 95% CI = 1.01 to 1.07) and higher HbA1c levels (OR per 1-SD = 1.09, 95% CI = 1.00 to 1.19) increased colorectal cancer risk, although these findings may have been biased by pleiotropy. Higher HbA1c concentrations increased rectal cancer risk in men (OR per 1-SD = 1.21, 95% CI = 1.05 to 1.40), but not in women.

CONCLUSIONS

Our results support a causal effect of higher fasting insulin, but not glucose traits or type 2 diabetes, on increased colorectal cancer risk. This suggests that pharmacological or lifestyle interventions that lower circulating insulin levels may be beneficial in preventing colorectal tumorigenesis.

Lack of Association Between PDCD-1 Polymorphisms and Colorectal Cancer Risk: A Case-Control Study

Functional variants of immune-related genes may be implicated in the occurrence of colorectal cancer (CRC). In this study, Programmed cell death (PDCD)-1.6 (rs10204525 T/C), PDCD-1.7 (rs7421861 A/G), and PDCD-1.9 (rs2227982 A/G) loci were selected to explore gene expression and the potential susceptibility to the development of CRC. Here, 1,003 CRC patients and 1,303 controls were included and three PDCD-1 tagging loci were selected and analyzed by using SNPscan genotyping assays. SHESIS software was harnessed to obtain the haplotypes of the PDCD-1 gene. We found that the genotype and allele distribution of PDCD-1 tagging loci did not significantly affect the risk of CRC. Adjustment for body mass index, age, smoking, alcohol using and sex also found that PDCD-1 tagging loci did not influence the occurrence of CRC. In conclusion, this study suggests that the PDCD-1 tagging loci (rs10204525, rs7421861, and rs2227982) are not correlated with CRC susceptibility.

Circulating Sex Hormone Levels and Colon Cancer Risk in Men: A Nested Case-Control Study and Meta-Analysis

BACKGROUND

Endogenous sex hormones may contribute to higher colorectal cancer incidence rates in men compared with women, but despite an increased number of studies, clear evidence is lacking.

METHODS

We conducted a comprehensive nested case-control study of circulating concentrations of sex hormones, sex hormone precursors, and sex hormone binding globulin (SHBG) in relation to subsequent colon cancer risk in European men. Concentrations were measured using liquid LC/MS-MS in prospectively collected plasma samples from 690 cases and 690 matched controls from the European Prospective Investigation into Cancer and Nutrition (EPIC) and the Northern Sweden Health and Disease Study (NSHDS) cohorts. Multivariable conditional logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (CI). In addition, we conducted a meta-analysis of previous studies on men.

RESULTS

Circulating levels of testosterone (OR, 0.68; 95% CI, 0.51-0.89) and SHBG (OR, 0.77; 95% CI, 0.62-0.96) were inversely associated with colon cancer risk. For free testosterone, there was a nonsignificant inverse association (OR, 0.83; 95% CI, 0.58-1.18). In a dose-response meta-analysis of endogenous sex hormone levels, inverse associations with colorectal/colon cancer risk were found for testosterone [relative risks (RR) per 100 ng/dL = 0.98; 95% CI, 0.96-1.00; I2 = 22%] and free testosterone (RR per 1 ng/dL = 0.98; 95% CI, 0.95-1.00; I2 = 0%).

CONCLUSIONS

Our results provide suggestive evidence for the association between testosterone, SHBG, and male colon cancer development.

IMPACT

Additional support for the involvement of sex hormones in male colon cancer.

Molecular Biologic and Epidemiologic Insights for Preventability of Colorectal Cancer

The etiology of colorectal cancer (CRC) has been informed from both a molecular biology perspective, which concerns the study of the nature, timing, and consequences of mutations in driver genes, and epidemiology, which focuses on identifying risk factors for cancer. For the most part, these fields have developed independently, and it is thus important to consider them in a more integrated manner. The molecular mutational perspective has stressed the importance of mutations due to replication of adult stem cells, and the molecular fingerprint of most CRCs does not suggest the importance of direct carcinogens. Epidemiology has identified numerous modifiable risk factors that account for most CRCs, most of which are not direct mutagens. The distribution of CRCs across the large bowel is not uniform, which is possibly caused by regional differences in the microbiota. Some risk factors are likely to act through or interact with the microbiota. The mutational perspective informs when risk factors may begin to operate in life and when they may cease to operate. Evidence from the mutational model and epidemiology supports that CRC risk factors begin early in life and may contribute to the risk of early-onset CRC. Later in carcinogenesis, there may be a "point of no return" when sufficient mutations have accumulated, and some risk factors do not affect cancer risk. This period may be at least 5-15 years for some risk factors. A more precise knowledge of timing of risk factor to cancer is required to inform preventive efforts.

Long-Term Statin Use, Total Cholesterol Level, and Risk of Colorectal Cancer: A Prospective Cohort Study

INTRODUCTION

Statin use has been examined as a potential chemopreventive strategy against colorectal cancer (CRC). Previous studies have not been able to investigate this topic with adequate follow-up time or disentangle the effects of statin use and total cholesterol level. We investigated prospectively this topic.

METHODS

Eligible participants (100,300 women and 47,991 men) in the Nurses' Health Study and Health Professionals Follow-Up Study were followed for up to 24 years. Cox proportional hazards models were used to estimate hazard ratios and 95% confidence intervals.

RESULTS

We documented 2,924 incident CRC cases during follow-up. In fully adjusted analyses, longer duration of statin use was associated with higher risk of colon cancer (hazard ratios, the 95% confidence interval was 1.09, 0.95-1.25 for 1-5 years; 1.16, 0.99-1.36 for 6-10 years; 1.08, 0.81-1.44 for 11-15 years; 1.85, 1.30-2.61 for >15 years; vs never users, P = 0.004 for trend) rather than rectal cancer. The risk elevation was driven by proximal colon cancer (1.16, 0.98-1.38 for 1-5 years; 1.19, 0.98-1.45 for 6-10 years; 1.25, 0.89-1.74 for 11-15 years; 2.17, 1.46-3.24 for >15 years; vs never users, P = 0.001 for trend) rather than distal colon cancer. The results remained robust in analyses among participants with hypercholesterolemia or who never received screening. Total cholesterol level was not associated with CRC risk.

DISCUSSION

This study does not support benefit of statin use in CRC chemoprevention or any association between total cholesterol level and CRC risk. On the contrary, long-term statin use may be associated with increased colon cancer risk (driven by proximal colon cancer).

The Role of Diet and Lifestyle in Early-Onset Colorectal Cancer: A Systematic Review

Simple Summary

This systematic review sifted through the exogenous dietary and lifestyle risk factors associated with early-onset colorectal cancer, going through the putative involvement of these exogenous risk factors in epigenetic and microbiota modifications. Given the burden of early-onset colorectal cancer and its globally increasing trend with scant literature on its pathogenesis, we believe it would be of benefit to highlight the importance of further systematic and large studies. Indeed, dietary and lifestyle modification could complement colorectal screening for early-onset colorectal cancer prevention.

Abstract

The incidence of early-onset colorectal cancer, defined as colorectal cancer occurring in young adults under the age of 50, is increasing globally. Knowledge of the etiological factors in young adults is far from complete. Questionable eoCRCs’ exogenous factors are represented by processed meat, sugary drinks, alcohol, Western dietary pattern, overweight and obesity, physical inactivity, and smoking, though with heterogeneous results. Therefore, we performed a systematic review to summarize the current evidence on the role of diet and lifestyle as eoCRC risk factors. We systematically searched PubMed, Scopus, and EMBASE up to July 2021, for original studies evaluating diet, alcohol, physical activity, BMI, and smoking in eoCRC and included twenty-six studies. Indeed, the exogenous factors could represent modifiable key factors, whose recognition could establish areas of future interventions through public health strategies for eoCRC primary prevention. Additionally, we discussed the role of additional non-modifiable risk factors, and of epigenetic regulation and microbiota as mediators of the eoCRC triggered by diet and lifestyle.

Association of preserved vegetable consumption and prevalence of colorectal polyps: results from the Lanxi Pre-colorectal Cancer Cohort (LP3C)

PURPOSE

Although fresh vegetable consumption has been linked with a lower risk of colorectal polyps, a precursor lesion for colorectal cancer (CRC), the association between preserved vegetable consumption and colorectal polyps is unknown. We aimed to assess the association of preserved vegetable intake with the prevalence of colorectal polyps with the consideration of subsites, sizes and multiplicity of polyps.

METHODS

We analyzed the cross-sectional data from 40-80 years Chinese at a high risk of CRC from the Lanxi Pre-colorectal Cancer Cohort (LP3C) baseline survey, which was conducted between March 2018 and December 2019. Dietary information was obtained via a validated food frequency questionnaire. Multivariate logistic regression was employed to estimate the odds ratios (ORs) and 95% confidence intervals (CIs) of preserved vegetable consumption and the prevalence of colorectal polyps.

RESULTS

Of 6783 eligible participants in 2018-2019 survey of LP3C, 2064 prevalent colorectal polyp cases were identified. In the multivariable-adjusted model, preserved vegetable consumption was positively associated with the prevalence of colorectal polyps (OR for fourth vs. first quartile: 1.18; 95% CI 1.01-1.36; P trend = 0.02). The similar association was also detected for small polyps [OR_{Q4 vs Q1} (95% CI): 1.17 (1.00-1.37); P trend = 0.03]. The similar trend was detected for multiple polyps [OR _{Q4 vs Q1} (95% CI):1.27 (0.98-1.64); P trend = 0.04], proximal colon polyps [OR_{Q4 vs Q1} (95% CI): 1.12 (0.90-1.38); P trend = 0.07], and single polyp [OR_{Q4 vs Q1} (95% CI) for 1.15 (0.98-1.35); P trend = 0.06]. No significant association was observed for distal colon [OR_{Q4 vs Q1} (95% CI) 1.19 (0.98-1.45); P trend = 0.09]. Replacing one serving per day of preserved vegetables with fresh vegetables was related to 20%, 23%, and 37% lower prevalence of overall, small, and multiple polyps, respectively.

CONCLUSIONS

Preserved vegetable consumption was associated with a higher prevalence of colorectal polyps in a Chinese population at a high risk of CRC. Replacing preserved vegetables with fresh vegetables may be conducive to lower prevalent colorectal polyps.

A fecal-based test for the detection of advanced adenoma and colorectal cancer: a case-control and screening cohort study

BACKGROUND

Colorectal cancer (CRC) is the leading cause of cancer death worldwide. Screening is a confirmed way to reduce the incidence and mortality rates of CRC. This study aimed to identify a fecal-based, noninvasive, and accurate method for detection of colorectal cancer (CRC) and advanced adenoma (AA).

METHODS

Through detection in tissue (n = 96) and fecal samples (n = 88) and tested in an independent group of fecal samples (n = 294), the methylated DNA marker ITGA4 and bacterial markers Fusobacterium nucleatum (Fn) and Pepetostreptococcusanaerobius (Pa) were identified from the candidate biomarkers for CRC and AA detection. A prediction score (pd-score) was constructed using the selected markers and fecal immunochemical test (FIT) for distinguishing AA and CRC from healthy subjects by logistic regression method. The diagnostic performance of the pd-score was compared with FIT and validated in the external validation cohort (n = 117) and in a large CRC screening cohort.

RESULTS

The pd-score accurately identified AA and CRC from healthy subjects with an area under the curve (AUC) of 0.958, at a specificity of 91.37%; the pd-score showed sensitivities of 95.38% for CRC and 70.83% for AA, respectively. In the external validation cohort, the sensitivities of the pd-score for CRC and AA detection were 94.03% and 80.00%, respectively. When applied in screening, the pd-score identified 100% (11/11) of CRC and 70.83% (17/24) of AA in participants with both colonoscopy results and qualified fecal samples, showing an improvement by 41.19% compared to FIT.

CONCLUSIONS

The current study developed a noninvasive and well-validated approach for AA and CRC detection, which could be applied widely as a diagnostic and screening test.

Rising incidence of colorectal cancer in individuals younger than 50 years and increasing mortality from rectosigmoid cancer in England

AIM

The aim was to describe changes in incidence and mortality from colorectal cancer (CRC) in England by analysing data available from the National Cancer Registration and Analysis Service (NCRAS, 2001-2017).

METHODS

Data analysis was undertaken to interpret trends and patterns in age-standardized incidence and death rates from CRC, including sub-analyses by six age groups (0-24, 25-49, 50-59, 60-69, 70-79, 80+) and three sites of cancer-colonic, rectosigmoid and rectal.

RESULTS

Overall CRC incidence remained relatively stable-70.1 cases per 100 000 individuals (95% CI 69.3-71.0) in 2001 and 68.8 cases (95% CI 68.0-69.5) in 2017. Sub-analysis demonstrates a quarter fewer incidence of rectosigmoid cancer (-27%). This is counterbalanced by a 3% rise in colon cancers. The age-standardized incidence rate of CRC increased by 59% in the 25-49 age group. In the over 50s, CRC incidence remained stable, with reductions seen in rectosigmoid cancer (50-59 years, -19%; 60-69, -26%; 70-79, -39%; 80+, -27%). Overall, mortality improved (-18.7%), primarily as a result of the reduction in deaths from colon (-31.6%) and rectal cancers (-25.1%). Deaths from the small incident number of rectosigmoid cancers, however, demonstrated a significant increase overall (+166.7%). Grouped age-standardized death rate analyses showed increasing death rates in the under 50s (+28.3%) compared to declining rates in the over 50s (-15.8%).

CONCLUSIONS

There is a clear trend in increased incidence and mortality in individuals under 50 years old. There is also a trend to increased mortality from rectosigmoid cancer. These findings should have implications for national screening programme extension to under 50s and a call to arms for appropriate identification, staging and treatment of rectosigmoid cancers.

To what extent is male excess risk of advanced colorectal neoplasms explained by known risk factors? Results from a large German screening population

Colorectal cancer (CRC) incidence and prevalence of its precursors are substantially higher among males than among females in most countries but the reasons for the male excess risk are incompletely understood. We aimed to assess to what extent it is explained by known risk factors. Prevalence of advanced neoplasia (AN, ie, CRC or advanced adenoma) and CRC risk and preventive factors were ascertained among 15 985 participants of screening colonoscopy aged 55-79 years in Germany. Logistic regression was used to calculate odds ratios (ORs) for the association between male sex and AN with and without adjustment for known risk and preventive factors. In age-adjusted comparisons, men had 2-fold increased risk for AN compared to women (OR = 1.98, 95% confidence interval [CI] 1.79-2.19). After comprehensive adjustment for medical, lifestyle and dietary factors, the OR was reduced to 1.52 (95% CI 1.30-1.77), suggesting that these factors accounted for 47% of male excess risk. Male excess risk increased from proximal colon to distal colon and rectum, with age-adjusted ORs (95% CI) of 1.63 (1.38-1.91), 2.13 (1.85-2.45) and 2.36 (1.95-2.85), respectively, and with the proportion of excess risk explained by covariates being lower for AN in the rectum (26%) than for AN in the proximal (52%) or distal colon (46%). Male excess risk was somewhat lower (age-adjusted OR 1.87) and explained excess risk was smaller (36%) when men were compared to women who never used hormone replacement therapy. In conclusion, most of the male excess risk and the potential to overcome it remain to be explored by further research.

Association of Habitual Preoperative Dietary Fiber Intake With Complications After Colorectal Cancer Surgery

IMPORTANCE

Postoperative complications are associated with increased morbidity and mortality among patients with colorectal cancer. As a modifiable factor associated with gut health, dietary fiber intake is of interest with regard to the risk of complications after surgery for colorectal cancer.

OBJECTIVE

To examine the association between preoperative dietary fiber intake and risk of complications after surgery for colorectal cancer.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study used data from the Colorectal Longitudinal, Observational Study on Nutritional and Lifestyle Factors (COLON) study, which recruited adult patients with colorectal cancer at any stage at diagnosis from 11 hospitals in the Netherlands between August 2010 and December 2017. The present study included patients with stage I to IV colorectal cancer who underwent elective abdominal surgery. Data were analyzed between December 2019 and September 2020.

EXPOSURES

Habitual dietary fiber intake was assessed at diagnosis using a 204-item food frequency questionnaire.

MAIN OUTCOMES AND MEASURES

Any complications, surgical complications, and anastomotic leakage occurring during the 30 days after surgery for colorectal cancer. The association between fiber intake and risk of postoperative complications was assessed using logistic regression analyses. Additional analyses stratified by sex, tumor location, and fiber source were performed.

RESULTS

Among the 1399 patients included in the analysis, the median age at inclusion was 66 years (interquartile range, 61-72 years) and 896 (64%) were men. Any complications occurred in 397 patients (28%), and surgical complications occurred in 235 patients (17%). Of 1237 patients with an anastomosis, 67 (5%) experienced anastomotic leakage. Higher dietary fiber intake (per 10 g per day) was associated with a lower risk of any complications (odds ratio [OR], 0.75; 95% CI, 0.62-0.92) and surgical complications (OR, 0.76; 95% CI, 0.60-0.97), whereas no association with anastomotic leakage was found (OR, 0.97; 95% CI, 0.66-1.43). Among women, higher dietary intake was associated with any complications (OR, 0.64; 95% CI, 0.44-0.94), whereas there was no association among men (OR, 0.79; 95% CI, 0.63-1.01). Fiber intake from vegetables (per 1 g per day) was inversely associated with any (OR, 0.90; 95% CI, 0.83-0.99) and surgical (OR, 0.87; 95% CI, 0.78-0.97) complications.

CONCLUSIONS AND RELEVANCE

In this cohort study, higher habitual dietary fiber intake before surgery was associated with a lower risk of postoperative complications among patients with colorectal cancer. The findings suggest that improving preoperative dietary fiber intake may be considered in future prehabilitation programs for patients undergoing surgery for colorectal cancer.

Nongenetic Determinants of Risk for Early-Onset Colorectal Cancer

Background

Incidence of early-onset (younger than 50 years of age) colorectal cancer (CRC) is increasing in many countries. Thus, elucidating the role of traditional CRC risk factors in early-onset CRC is a high priority. We sought to determine whether risk factors associated with late-onset CRC were also linked to early-onset CRC and whether association patterns differed by anatomic subsite.

Methods

Using data pooled from 13 population-based studies, we studied 3767 CRC cases and 4049 controls aged younger than 50 years and 23 437 CRC cases and 35 311 controls aged 50 years and older. Using multivariable and multinomial logistic regression, we estimated odds ratios (ORs) and 95% confidence intervals (CIs) to assess the association between risk factors and early-onset CRC and by anatomic subsite.

Results

Early-onset CRC was associated with not regularly using nonsteroidal anti-inflammatory drugs (OR = 1.43, 95% CI = 1.21 to 1.68), greater red meat intake (OR = 1.10, 95% CI = 1.04 to 1.16), lower educational attainment (OR = 1.10, 95% CI = 1.04 to 1.16), alcohol abstinence (OR = 1.23, 95% CI = 1.08 to 1.39), and heavier alcohol use (OR = 1.25, 95% CI = 1.04 to 1.50). No factors exhibited a greater excess in early-onset compared with late-onset CRC. Evaluating risks by anatomic subsite, we found that lower total fiber intake was linked more strongly to rectal (OR = 1.30, 95% CI = 1.14 to 1.48) than colon cancer (OR = 1.14, 95% CI = 1.02 to 1.27; P = .04).

Conclusion

In this large study, we identified several nongenetic risk factors associated with early-onset CRC, providing a basis for targeted identification of those most at risk, which is imperative in mitigating the rising burden of this disease.

Causal Effects of Lifetime Smoking on Breast and Colorectal Cancer Risk: Mendelian Randomization Study

BACKGROUND

Observational evidence has shown that smoking is a risk factor for breast and colorectal cancer. We used Mendelian randomization (MR) to examine causal associations between smoking and risks of breast and colorectal cancer.

METHODS

Genome-Wide Association Study summary data were used to identify genetic variants associated with lifetime amount of smoking (n = 126 variants) and ever having smoked regularly (n = 112 variants). Using two-sample MR, we examined these variants in relation to incident breast (122,977 cases/105,974 controls) and colorectal cancer (52,775 cases/45,940 controls).

RESULTS

In inverse-variance weighted models, a genetic predisposition to higher lifetime amount of smoking was positively associated with breast cancer risk [OR per 1-SD increment: 1.13; 95% confidence interval (CI): 1.00-1.26; P = 0.04]; although heterogeneity was observed. Similar associations were found for estrogen receptor-positive and estrogen receptor-negative tumors. Higher lifetime amount of smoking was positively associated with colorectal cancer (OR per 1-SD increment, 1.21; 95% CI, 1.04-1.40; P = 0.01), colon cancer (OR, 1.31; 95% CI, 1.11-1.55; P < 0.01), and rectal cancer (OR, 1.36; 95% CI, 1.07-1.73; P = 0.01). Ever having smoked regularly was not associated with risks of breast (OR, 1.01; 95% CI, 0.90-1.14; P = 0.85) or colorectal cancer (OR, 0.97; 95% CI, 0.86-1.10; P = 0.68).

CONCLUSIONS

These findings are consistent with prior observational evidence and support a causal role of higher lifetime smoking amount in the development of breast and colorectal cancer.

IMPACT

The results from this comprehensive MR analysis indicate that lifetime smoking is a causal risk factor for these common malignancies.

Toward Colorectal Cancer Biomarkers: The Role of Genetic Variation, Wnt Pathway, and Long Noncoding RNAs

Colorectal cancer (CRC) is the third leading cause of death worldwide, comprising nearly 8% of cancer-related deaths per year. In South Korea, for example, CRC is the second most common cancer in men, and third in women. This study reports on the association of CRC with genetic variations in long noncoding RNAs, activators, and inhibitors of a cell proliferation pathway. Five normal colon mucosa tissue samples and their matched five-stage IV CRC samples were evaluated (dataset Gene Expression Omnibus accession: GSE50760). We identified more than 5000 differentially expressed genes (DEGs). The Wnt pathway had the greatest portion of DEGs, including activators, inhibitors, and associated long noncoding RNAs (lncRNAs), suggesting the importance of Wnt pathway in CRC. The following genes were aberrantly expressed: WIF1, SFRP4, CD82, WNT2, WNT3, WNT5A, HOTAIR, CRNDE, and UCA1. Notably, HOTAIR is known to silence WIF1, and WIF1 inhibits the Wnt ligands to negatively regulate the pathway. The lncRNA CRNDE positively regulates WNT5A, while UCA1 positively regulates WNT2 and WNT3. We note that HOTAIR was unable to silence WIF1. CRNDE and UCA1 were found to be upregulated, which may explain the high expression of the WIF1 targets. Furthermore, 10 single-nucleotide polymorphisms (SNPs) were identified in five of the candidate genes above. A possible novel SNP in CD82, chr11:44619242T > C, was predicted to introduce a ZBTB7A binding site. These SNPs are hypothesized to contribute to aberrant and discrepant regulation of the Wnt pathway in a context of CRC pathogenesis. These findings collectively inform future research on diagnostics and therapeutics innovation in CRC.

Rising incidence of early-onset colorectal cancer - a call to action

The incidence of early-onset colorectal cancer (CRC), which occurs in individuals <50 years of age, has been increasing worldwide and particularly in high-income countries. The reasons for this increase remain unknown but plausible hypotheses include greater exposure to potential risk factors, such as a Western-style diet, obesity, physical inactivity and antibiotic use, especially during the early prenatal to adolescent periods of life. These exposures can not only cause genetic and epigenetic alterations in colorectal epithelial cells but also affect the gut microbiota and host immunity. Early-onset CRCs have differential clinical, pathological and molecular features compared with later-onset CRCs. Certain existing resources can be utilized to elucidate the aetiology of early-onset CRC and inform the development of effective prevention, early detection and therapeutic strategies; however, additional life-course cohort studies spanning childhood and young adulthood, integrated with prospective biospecimen collections, omics biomarker analyses and a molecular pathological epidemiology approach, are needed to better understand and manage this disease entity. In this Perspective, we summarize our current understanding of early-onset CRC and discuss how we should strategize future research to improve its prevention and clinical management.

Ethnicity Influences Risk of Inflammatory Bowel Disease (IBD)-Associated Colon Cancer: A Cross-sectional Analysis of Dysplasia Prevalence and Risk Factors in Hispanics and Non-Hispanic Whites With IBD

Background

Inflammatory bowel disease (IBD) is an emerging disease in Hispanics. In this study, we examine the prevalence of IBD-related colon dysplasia (IBD-dys) in Hispanics versus non-Hispanic whites (NHWs) and compare differences in established clinical and environmental risk factors.

Methods

We performed a cross-sectional analysis on adult Hispanics and NHWs with IBD who met criteria for colorectal cancer surveillance and were followed at our center between 2008 and 2018. Clinical variables and IBD phenotype were recorded. Lifestyle IBD-dys risk factors were examined, including smoking and lack of physical activity. Using multivariable regression, we compared the prevalence of IBD-dys in Hispanics versus NHW, using relevant covariates. Receiver operating characteristic and area under the curve were performed to find the best fitting model.

Results

A total of 445 IBD patients were included (148 Hispanics and 297 NHWs). IBD phenotype was similar between groups, except that Hispanics had shorter disease duration, a lower frequency of Crohn’s disease-related complications, and lower reported use of steroids. Frequency of surveillance colonoscopies was similar between Hispanics and NHW. There were no differences in median body mass index between Hispanics and NHW [26.5 (IQR 6.0) vs 25.0 (IQR 6.0), P = 0.40]. Hispanics were less likely than NHW to consume alcohol but smoking history was similar between groups. Three out of 148 Hispanic patients had IBD-dys (2.02%) compared to 29 out of 297 NHWs (9.76%). Adjusting for disease duration, primary sclerosing cholangitis, family history of colon cancer, and smoking, Hispanics had a lower prevalence of IBD-dys compared to NHW [ORadjusted = 0.207 (95% CI 0.046–0.938), P = 0.008].

Conclusions

Hispanics with IBD undergoing surveillance had a lower prevalence of IBD-dys than their NHW counterparts, despite similar risk factors. Future studies should examine dietary and microbial factors that may explain differences in risk.

Aspects of colorectal cancer screening, methods, age and gender

Colorectal cancer (CRC) is, besides breast, prostate, lung and skin cancers, the most common cancer worldwide and is suitable for screening. The incidence of CRC varies considerably in different parts of the world: in well-developed countries, the incidence is between 30 and 70 per 100 000 inhabitants, whereas in less-developed countries such as sub-Saharan Africa, it is 10-20/100 000 inhabitants. Women have a lower incidence of CRC, which is usually one-third of total incidence. Several studies have shown that it is possible to decrease mortality from CRC with about 20%, which is evidenced through the data from countries with screening programmes. Though the method of choice to identify blood samples in faecal matter is under debate, the most feasible way is to perform colonoscopy. Other methods include more advanced faecal analyses, testing for mutations from CRC, sigmoidoscopy, CT colonoscopy or optical colonoscopy. Colonoscopy is in most countries not available in sufficient amount and has to be carried out with great accuracy; otherwise, lesions will be missed to identify, thus leading to complications. Gender is an issue in CRC screening, as women have about 20% fewer colorectal adenomas and CRCs, but they also have more right-sided lesions, which are more difficult to detect with tests for faecal blood since they create less blood in faeces. Thus, other strategies may have to be developed for women in order for screening to have the same effect. It is essential to introduce colorectal cancer screening in all countries together with other clinical pieces of advice such as information on smoking, obesity and exercise in order to reduce one of the most dangerous cancers.

Clinical characteristics, medical service utilization, and expenditure for colorectal cancer in China, 2005 to 2014: Overall design and results from a multicenter retrospective epidemiologic survey

BACKGROUND

Colorectal cancer (CRC) is the third most common cancer in China, however, publicly available, descriptive information on the clinical epidemiology of CRC is limited.

METHODS

Patients diagnosed with primary CRC during 2005 through 2014 were sampled from 13 tertiary hospitals in 9 provinces across China. Data related to sociodemographic characteristics, the use of diagnostic technology, treatment adoption, and expenditure were extracted from individual medical records.

RESULTS

In the full cohort of 8465 patients, the mean ± SD age at diagnosis was 59.3 ± 12.8 years, 57.2% were men, and 58.7% had rectal cancer. On average, 14.4% of patients were diagnosed with stage IV disease, and this proportion increased from 13.5% in 2005 to 20.5% in 2014 (P value for trend < .05). For diagnostic techniques, along with less use of x-rays (average, 81.6%; decreased from 90.0% to 65.7%), there were increases in the use of computed tomography (average, 70.4%; increased from 4.5% to 90.5%) and magnetic resonance imaging (average, 8.8%; increased from 0.1% to 20.4%) over the study period from 2005 to 2014. With regard to treatment, surgery alone was the most common (average, 50.1%), but its use decreased from 51.3% to 39.8% during 2005 through 2014; and the use of other treatments increased simultaneously, such as chemotherapy alone (average, 4.1%; increased from 4.1% to 11.9%). The average medical expenditure per patient was 66,291 Chinese Yuan (2014 value) and increased from 47,259 to 86,709 Chinese Yuan.

CONCLUSIONS

The increasing proportion of late-stage diagnoses presents a challenge for CRC control in China. Changes in diagnostic and treatment options and increased expenditures are clearly illustrated in this study. Coupled with the recent introduction of screening initiatives, these data provide an understanding of changes over time and may form a benchmark for future related evaluations of CRC interventions in China.

Long-Term Colorectal Cancer Incidence and Mortality After Colonoscopy Screening According to Individuals' Risk Profiles

BACKGROUND

It remains unknown whether the benefit of colonoscopy screening against colorectal cancer (CRC) and the optimal age to start screening differ by CRC risk-profile.

METHODS

Among 75,873 women and 42,875 men, we defined a CRC risk score (0-8) based on family history, aspirin, height, body mass index, smoking, physical-activity, alcohol, and diet. We calculated colonoscopy screening-associated hazard ratios (HRs) and absolute risk reductions (ARRs) for CRC incidence and mortality and age-specific CRC cumulative incidence according to risk score. All statistical tests were 2-sided.

RESULTS

During a median of 26 years' follow-up, we documented 2,407 CRC cases and 874 CRC deaths. While the screening-associated hazard ratio did not vary by risk score, the absolute risk reductions in multivariable-adjusted 10-year CRC incidence more than doubled for individuals with score 6-8 (ARR = 0.34%, 95% CI = 0.26% to 0.42%) compared to 0-2 (ARR = 0.15%, 95% CI = 0.12% to 0.18%; Ptrend<0.001). Similar results were found for CRC mortality (ARR = 0.22% [95% CI = 0.21% to 0.24%] vs. 0.08% [95% CI = 0.07% to 0.08%]; Ptrend<0.001). The absolute risk reduction in mortality of distal-colon and rectal cancers was four-fold higher for score 6-8 than 0-2 (distal-colon cancer: ARR = 0.08% [95% CI = 0.07% to 0.08%] vs. 0.02% [95% CI = 0.02% to 0.02%], Ptrend <0.001; rectal cancer: ARR = 0.08% [95% CI = 0.08% to 0.09%] vs. 0.02% [95% CI = 0.02% to 0.03%], Ptrend <0.001). When using age 45 years as the benchmark to start screening, individuals with risk score of 0-2, 3, 4, 5, and 6-8 attained the threshold CRC risk level (10-year cumulative risk of 0.47%) at age 51, 48, 45, 42, and 38 years, respectively.

CONCLUSIONS

The absolute benefit of colonoscopy screening is more than twice higher for individuals with the highest than lowest CRC risk profile. Individuals with a high and low risk profile may start screening up to 6-7 years earlier and later, respectively, than the recommended age 45 years.

Immuno-Oncolytic Viruses: Emerging Options in the Treatment of Colorectal Cancer

Colorectal cancer is the third most common neoplasm in the world and the third leading cause of cancer-related deaths in the USA. A safer and more effective therapeutic intervention against this malignant carcinoma is called for given the limitations and toxicities associated with the currently available treatment modalities. Immuno-oncolytic or oncolytic virotherapy, the use of viruses to selectively or preferentially kill cancer cells, has emerged as a potential anticancer treatment modality. Oncolytic viruses act as double-edged swords against the tumors through the direct cytolysis of cancer cells and the induction of antitumor immunity. A number of such viruses have been tested against colorectal cancer, in both preclinical and clinical settings, and many have produced promising results. Oncolytic virotherapy has also shown synergistic antitumor efficacy in combination with conventional treatment regimens. In this review, we describe the status of this therapeutic approach against colorectal cancer at both preclinical and clinical levels. Successes with and the challenges of using oncolytic viruses, both as monotherapy and in combination therapy, are also highlighted.

Serum lipid profiles and risk of colorectal cancer: a prospective cohort study in the UK Biobank

BACKGROUND

It remains unclear whether serum lipids influence colorectal cancer (CRC) risk.

METHODS

We conducted a prospective cohort study of 380,087 adults aged 40-69 years in the UK Biobank. Serum high-density cholesterol, low-density cholesterol, total cholesterol, triglycerides, and apolipoprotein A and B were measured. We used Cox proportional hazard models to estimate the multivariable hazard ratios (HRs) of CRC according to one standard deviation (SD) increment in serum lipids. We conducted subgroup analysis by tumour anatomical subsites.

RESULTS

During a median of 10.3 years of follow-up, we documented 2667 incident CRC cases. None of the lipid biomarkers was associated with the risk of CRC after adjusting for potential confounding factors, including body mass index and waist circumference. When assessed by cancer subsites, serum triglycerides was associated with an increased risk of cancer in the caecum and transverse colon, with the HR of 1.12 (95% CI, 1.00-1.25) and 1.29 (95% CI, 1.09-1.53), respectively; and apolipoprotein A was associated with a lower risk of hepatic flexure cancer (HR, 0.73, 95% CI, 0.56-0.96).

CONCLUSIONS

Serum lipid profiles were not associated with colorectal cancer risk after adjusting for obesity indicators. The potential subsite-specific effects of triglycerides and apolipoprotein A require further confirmation.