Are Colon and Rectal Cancer Two Different Tumor Entities? A Proposal to Abandon the Term Colorectal Cancer. Int J Mol Sci. 2018;19. [PMID: 30200215 PMCID: PMC6165083 DOI: 10.3390/ijms19092577]

Evolutionary patterns of chromosomal instability and mismatch repair deficiency in proximal and distal colorectal cancer

AIM

Colorectal carcinomas (CRCs) progress through heterogeneous pathways. The aim of this study was to analyse whether or not the cytogenetic evolution of CRC is linked to tumour site, level of chromosomal imbalance and metastasis.

METHOD

A set of therapy-naïve pT3 CRCs comprising 26 proximal and 49 distal pT3 CRCs was studied by combining immunohistochemistry of mismatch repair (MMR) proteins, microsatellite analyses and molecular karyotyping as well as clinical parameters.

RESULTS

A MMR deficient/microsatellite-unstable (dMMR/MSI-H) status was associated with location of the primary tumour proximal to the splenic flexure, and dMMR/MSI-H tumours presented with significantly lower levels of chromosomal imbalances compared with MMR proficient/microsatellite-stable (pMMR/MSS) tumours. Oncogenetic tree modelling suggested two evolutionary clusters characterized by dMMR/MSI-H and chromosomal instability (CIN), respectively, for both proximal and distal CRCs. In CIN cases, +13q, -18q and +20q were predicted as preferentially early events, and -1p, -4 -and -5q as late events. Separate oncogenetic tree models of proximal and distal cases indicated similar early events independent of tumour site. However, in cases with high CIN defined by more than 10 copy number aberrations, loss of 17p occurred earlier in cytogenetic evolution than in cases showing low to moderate CIN. Differences in the oncogenetic trees were observed for CRCs with lymph node and distant metastasis. Loss of 8p was modelled as an early event in node-positive CRC, while +7p and +8q comprised early events in CRC with distant metastasis.

CONCLUSION

CRCs characterized by CIN follow multiple, interconnected genetic pathways in line with the basic 'Vogelgram' concept proposed for the progression of CRC that places the accumulation of genetic changes at centre of tumour evolution. However, the timing of specific genetic events may favour metastatic potential.

The Association of Metformin, Other Antidiabetic Medications, and Statins With the Prognosis of Colon Cancer in Patients With Type 2 Diabetes: A Retrospective Cohort Study

BACKGROUND

Use of metformin and statins have been associated with improved prognosis of colon cancer (CC) in patients with type 2 diabetes (T2D). We examined the survival from CC in relation to the use of metformin, other oral antidiabetic medications (ADM), insulin, and statins in T2D patients.

MATERIALS AND METHODS

A cohort (n = 2252) of persons with pre-existing T2D diagnosed with incident CC between 1998 and 2011 was identified from several Finnish registers. Cox models were fitted for cause-specific mortality rates to obtain adjusted estimates of the hazard ratios (HR) with 95% confidence intervals (CI) in relation to use of ADM and statins before the CC diagnosis. Cox models were also fitted for mortality in relation to post-diagnostic use of the medications treating these as time-dependent exposures, and starting follow-up 1 year after the CC diagnosis.

RESULTS

Pre- and post-diagnostic metformin use was weakly associated with the risk of CC-related death (HR .75; 95% CI .58-.99, and HR .78; 95% CI .54-1.14, respectively) compared to the use of other oral ADMs. Pre- and post-diagnostic statin use predicted a reduced risk of CC-related death (HR .83; 95% CI .71- .98, and HR .69; 95% CI .54-.89, respectively).

CONCLUSION

Additional evidence was found for use of statins being associated with an improved survival from CC in patients with pre-existing T2D, but for metformin use the evidence was weaker.

Patient-centered developments in colon- and rectal cancer with a multidisciplinary international team: From translational research to national guidelines

Rarely, scientific developments centered around the patient as a whole are published. Our multidisciplinary group, headed by gastrointestinal surgeons, applied this research philosophy considering the most important aspects of the diseases "colon- and rectal cancer" in the long-term developments. Good expert cooperation/knowledge at the Comprehensive Cancer Center Ulm (CCCU) were applied in several phase III trials for multimodal treatments of primary tumors (MMT) and metastatic diseases (involving nearly 2000 patients and 64 centers), for treatment individualization of MMT and of metastatic disease, for psycho-oncology/quality of life involving the patients' wishes, and for disease prevention. Most of the targets initially were heavily rejected/discussed in the scientific communities, but now have become standards in treatments and national guidelines or are topics in modern translational research protocols involving molecular biology for e.g., "patient centered individualized treatment". In this context we also describe the paths we had to tread in order to realize our new goals, which at the end were highly beneficial for the patients from many points of view. This description is also important for students and young researchers who, with an actual view on our recent developments, might want to know how medical progress was achieved.

Blood Bacterial DNA Load and Profiling Differ in Colorectal Cancer Patients Compared to Tumor-Free Controls

Inflammation and immunity are linked to intestinal adenoma (IA) and colorectal cancer (CRC) development. The gut microbiota is associated with CRC risk. Epithelial barrier dysfunction can occur, possibly leading to increased intestinal permeability in CRC patients. We conducted a case-control study including 100 incident histologically confirmed CRC cases, and 100 IA and 100 healthy subjects, matched to cases by center, sex and age. We performed 16S rRNA gene analysis of blood and applied conditional logistic regression. Further analyses were based on negative binomial distribution normalization and Random Forest algorithm. We found an overrepresentation of blood 16S rRNA gene copies in colon cancer as compared to tumor-free controls. For high levels of gene copies, community diversity was higher in colon cancer cases than controls. Bacterial taxa and operational taxonomic unit abundances were different between groups and were able to predict CRC with an accuracy of 0.70. Our data support the hypothesis of a higher passage of bacteria from gastrointestinal tract to bloodstream in colon cancer. This result can be applied on non-invasive diagnostic tests for colon cancer control.

Bacterial and Parasitic Pathogens as Risk Factors for Cancers in the Gastrointestinal Tract: A Review of Current Epidemiological Knowledge

The oncogenic potential of viral infections is well established and documented for many years already. However, the contribution of (commensal) bacteria and parasites to the development and progression of cancers has only recently gained momentum, resulting in a rapid growth of publications on the topic. Indeed, various bacteria and parasites have been suggested to play a role in the development of gastrointestinal cancer in particular. Therefore, an overview of the current epidemiological knowledge on the association between infections with bacteria and parasites and cancers of the gastrointestinal tract is needed. In this review, we summarized the methodological characteristics and main results of epidemiological studies investigating the association of 10 different bacteria (Bacteroides fragilis, Campylobacter spp., Clostridium spp., Enterococcus faecalis, Escherichia coli, Fusobacterium nucleatum, Porphyromonas gingivalis, non-typhoidal Salmonella, Salmonella Typhi, and Streptococcus spp.) and three parasites (Cryptosporidium spp., Schistosoma spp., and Strongyloides stercoralis) with gastrointestinal cancer. While the large body of studies based on microbiome sequencing provides valuable insights into the relative abundance of different bacterial taxa in cancer patients as compared to individuals with pre-malignant conditions or healthy controls, more research is needed to fulfill Koch's postulates, possibly making use of follow-up data, to assess the complex role of bacterial and parasitic infections in cancer epidemiology. Studies incorporating follow-up time between detection of the bacterium or parasite and cancer diagnosis remain valuable as these allow for estimation of cause-effect relationships.

Predicted Vitamin D Status and Colorectal Cancer Incidence in the Black Women's Health Study

BACKGROUND

Observational studies, mostly among White populations, suggest that low vitamin D levels increase colorectal cancer risk. African Americans, who are disproportionately burdened by colorectal cancer, often have lower vitamin D levels compared with other populations.

METHODS

We assessed predicted vitamin D score in relation to colorectal cancer among 49,534 participants in the Black Women's Health Study, a cohort of African American women followed from 1995 to 2017 through biennial questionnaires. We derived predicted vitamin D scores at each questionnaire cycle for all participants using a previously validated prediction model based on actual 25-hydroxyvitamin D values from a subset of participants. We calculated cumulative average predicted vitamin D score at every cycle by averaging scores from cycles up to and including that cycle. Using Cox proportional hazards regression, we estimated hazard ratios (HR) and 95% confidence intervals (CI) for colorectal cancer incidence according to predicted score quartiles.

RESULTS

Over follow-up, 488 incident colorectal cancers occurred. Compared with women in the highest quartile of predicted vitamin D score, those in the lowest had an estimated 41% (HR = 1.41; 95% CI, 1.05-1.90) higher colorectal cancer risk. Comparable HRs were 1.44 (95% CI, 1.02-2.01) for colon and 1.34 (95% CI, 0.70-2.56) for rectal cancer.

CONCLUSIONS

Low vitamin D status may lead to elevated colorectal cancer risk in African American women.

IMPACT

Our findings, taken together with established evidence that vitamin D levels are generally lower in African Americans than other U.S. groups, suggest that low vitamin D status may contribute to the disproportionately high colorectal cancer incidence among African Americans.

General insight into cancer: An overview of colorectal cancer (Review)

Cancer is currently among the leading causes of mortality globally. Colorectal cancer (CRC) ranks second among the most common types of cancer in terms of mortality worldwide. This type of cancer arises from mutations in the colonic and rectal epithelial tissues that target oncogenes, tumor suppressor genes and genes related to DNA repair mechanisms. The aim of the present review was to provide an explanation of CRC classification, which is carried out according to the histological subtype, location and molecular pathways implicated in its development. The pathogenic mechanisms implicated in CRC may involve one of three different molecular pathways: Chromosomal instability, microsatellite instability and cytosine preceding guanine island methylator phenotype. In addition, a variety of mutated genes associated with CRC, which affect certain signaling pathways, including DNA mismatch repair, cell cycle checkpoints and apoptotic pathways, were discussed. Moreover, a brief description of the risk factors and the symptoms associated with CRC was also provided. Finally, the treatment approaches to CRC were outlined.

The therapeutic and prognostic implications of immunobiology in colorectal cancer: a review

Colorectal cancer represents the second leading cause of cancer-related death worldwide. The therapeutic field of immuno-oncology has rapidly gained momentum, with strikingly promising results observed in clinical practice. Increasing emphasis has been placed on the role of the immune response in tumorigenesis, therapy and predicting prognosis. Enhanced understanding of the dynamic and complex tumour-immune microenvironment has enabled the development of molecularly directed, individualised treatment. Analysis of intra-tumoural lymphocyte infiltration and the dichotomisation of colorectal cancer into microsatellite stable and unstable disease has important therapeutic and prognostic implications, with potential to capitalise further on this data. This review discusses the latest evidence surrounding the tumour biology and immune landscape of colorectal cancer, novel immunotherapies and the interaction of the immune system with each apex of the tripartite of cancer management (oncotherapeutics, radiotherapy and surgery). By utilising the synergy of chemotherapeutic agents and immunotherapies, and identifying prognostic and predictive immunological biomarkers, we may enter an era of unprecedented disease control, survivorship and cure rates.

Anticancer Activity of Selenium Nanoparticles In Vitro Studies

Health systems worldwide consider cancer a disease that causes the highest number of deaths per year. The low efficacy of current cancer therapies has led other areas of science to search for new alternatives, including nanomaterial sciences. Selenium nanoparticles have anticancer activity, as revealed by in vitro tests performed on prostate, breast, cervical, lung, colorectal, and liver cancer cell lines. Studies attribute anticancer activity to the anti-metastatic effect due to the inhibition of migration and invasion processes. The antiproliferative effect is the low expression of molecules such as cyclin D1, cyclin E, and CDK2. In addition to the activation of cell apoptosis by caspase-dependent mechanisms, there is a low expression of anti-apoptotic proteins such as Bcl-2 and a high expression of the apoptotic proteins like Bax and Bad. Other studies attribute anticancer activity to the activation of cell necroptosis, where molecules such as TNF and IRF1 participate. The pharmacological potential of selenium nanoparticles depends primarily on the administered dose, particle size, and chemical composition. Furthermore, several studies have shown that the administration of these nanoparticles is safe due to their low toxicity in non-cancerous cells. In this review, the most relevant antecedents on the anticancer potential of selenium nanoparticles in prostate, breast, cervical, lung, liver, and colorectal cancer cell lines are discussed.

Blood lipids and risk of colon or rectal cancer: a Mendelian randomization study

PURPOSE

Recent Mendelian randomization (MR) studies derived inconsistent results of blood lipids' effect on colorectal cancer, and whether the blood lipids' effect on colon and rectal cancer is different is still unknown. Here, we sought to answer these questions.

METHODS

Primarily, we employed univariable MR to explore the blood lipids' effect on colon and rectal cancer, including high-density lipoprotein (HDL), low-density lipoprotein (LDL), total cholesterol and triglycerides. Then, multivariable MR was also employed to reassess each blood lipid's effect on the two cancers with adjustment of the other lipids. Reverse MR analysis was adopted to determine whether colon or rectal cancer could affect the levels of blood lipids. The Cochrane's Q value was used to evaluate the heterogeneity, and MR-PRESSO was used to appraise the pleiotropy.

RESULTS

Generally, we did not find any significant result between blood lipids and the colon/rectal cancer after Bonferroni correction in the univariable MR analysis. The multivariable MR analysis also obtained the same results. However, it should be noted that higher total cholesterol level might increase the risk of colon cancer (OR = 1.15 [1.01, 1.31], IVW p value = 0.029) but not rectal cancer (OR = 1.02 [0.85, 1.21], IVW p value = 0.853). Such causal relationship turned insignificant in the multivariable MR. The reverse MR analysis suggested that either colon or rectal cancer could increase the levels of blood lipids.

CONCLUSION

We found no association between blood lipids and risk of colon or rectal cancer, except for a positive association between total cholesterol and colon cancer risk.

The Association Between Treatment Interval and Survival in Patients With Colon or Rectal Cancer: A Systematic Review

BACKGROUND

Surgery for colon or rectal cancer is associated with a high incidence of complications, especially in patients with a low aerobic fitness. Those patients might benefit from a comprehensive preoperative workup including prehabilitation. However, time between diagnosis and treatment is often limited due to current treatment guidelines. To date, it is unclear whether the treatment interval can be extended without compromising survival.

METHODS

A systematic review concerning the association between treatment intervals and survival in patients who underwent elective curative surgery for colon or rectal cancer was performed. A search up to December 2020 was conducted in PubMed, Cinahl and Embase. Original research articles were eligible. Quality assessment was performed using the Downs and Black checklist.

RESULTS

Eleven observational studies were included (897 947 patients). In colon cancer, treatment intervals that were statistically significant associated with reduced overall survival or cancer-specific survival ranged between > 30 and > 84 days. In rectal cancer, only one out of four studies showed that treatment intervals > 49 days was associated with reduced cancer-specific survival.

CONCLUSIONS

This systematic review identified that studies investigating the association between treatment intervals and survival are heterogeneous with regard to treatment interval definitions, treatment interval time intervals and used outcome measures. These aspects need standardization before a reliable estimate of an optimal treatment interval can be made. In addition, further research should focus on establishing optimal treatment intervals in patients at high risk for postoperative complications, as particularly these patients might benefit from extended diagnosis to treatment intervals permitting comprehensive preoperative preparation.

Colon cancer patients with mismatch repair deficiency are more likely to present as acute surgical cases

BACKGROUND

The effect of the genetic imprint on the emergency presentation of colon cancer remains unclear. The disparity between tumours evolving along different carcinogenetic pathways has not been studied systematically. This retrospective multicenter cohort study evaluates the association between mismatch repair status and the risk for acute surgery of colon cancer.

PATIENTS AND METHODS

A retrospective multicenter cohort study including in total 870 patients from three different countries. Scandinavian cohort (Finland and Sweden), including a total of 412 patients operated between January 1, 1995 and December 31, 2010, was validated against a cohort from the Czech Republic, including a total of 458 patients, operated between January 1, 2018 and December 31, 2019. The proficiency or deficiency of mismatch repair was determined by immunohistochemistry. Primary outcome was the risk for acute colon cancer surgery given as the Odds Ratio (OR) in the univariable and multivariable analyses. Acute colon cancer surgery was defined as surgery performed during the same hospital admission as when the diagnosis of colon cancer was made.

RESULTS

Of the 870 patients (399 females [46%]) included in the analyses, median age at surgery was 69 [interquartile range, 61-76] years, deficient Mismatch Repair (dMMR) status was found in 190 patients (22%), and 179 patients (21%) underwent acute surgery during the same hospital admission as when the diagnosis of colon cancer was made. In the Scandinavian cohort, a significant association between dMMR status and acute surgery was seen in both the univariable (OR 1.82, 95% CI 1.11-3.02, P = 0.017) and the multivariable (OR = 2.21, 95% CI 1.28-3.95, P = 0.005) analyses. This was confirmed in the Czech validation cohort in both the univariable (OR = 1.94, 95% CI 1.09-3.26, P = 0.022) and the multivariable (OR = 1.77, 95% CI 1.15-3.18, P = 0.021) analyses.

CONCLUSION

This multicenter study reveals a strong association between acute colon cancer surgery and dMMR tumour status.

Survival Impact of Chronic Obstructive Pulmonary Disease or Acute Exacerbation on Patients with Rectal Adenocarcinoma Undergoing Curative Resection: A Propensity Score-Matched, Nationwide, Population-Based Cohort Study

PURPOSE

The survival effect of current smoking-related chronic obstructive pulmonary disease (COPD) and COPD with acute exacerbation (COPDAE) is unclear for patients with rectal adenocarcinoma undergoing curative resection.

METHODS

We recruited patients with clinical stage I-IIIC rectal adenocarcinoma from the Taiwan Cancer Registry Database who had received surgery. The Cox proportional hazards model was used to analyze all-cause mortality. We categorized the patients into two groups by using propensity score matching based on COPD status to compare overall survival outcomes: Group 1 (current smokers with COPD) and Group 2 (nonsmokers without COPD).

RESULTS

In the multivariate Cox regression analyses, the adjusted hazard ratio (aHR; 95% confidence interval (CI)) of all-cause mortality for Group 1 compared with Group 2 was 1.25 (1.04-1.51). The aHRs (95% cis) of all-cause mortality for frequency of ≥1 hospitalizations for COPDAE or ≥2 hospitalizations within 1 year before diagnosis were 1.17 (1.05-1.51) and 1.48 (1.03-2.41) compared with no COPDAE in patients with rectal adenocarcinoma undergoing curative resection.

CONCLUSION

In patients with rectal adenocarcinoma undergoing curative resection, being a current smoker with COPD (Group 1) was associated with worse survival outcomes than being a nonsmoker without COPD (Group 2). Being hospitalized at least once for COPDAE within 1 year before the diagnosis of rectal adenocarcinoma is an independent risk factor for poor overall survival in these patients, and a higher number of hospitalizations for COPDAE within 1 year before diagnosis was associated with poorer survival.

[The study of mRNA expression profiles of main cell function regulator genes in unchanged colonic mucosa from healthy donors]

A comparative analysis of molecular genetic phenotypes of mucous membrane cells in five anatomical regions of the colon in a group of healthy donors was conducted by comparing mRNA expression profiles of 62 genes involved in the regulation of vital cellular function. We used 181 biopsy samples of morphologically unchanged colonic mucosa, obtained from the colon (ascending, transverse-colon, descending, sigmoid) and rectum sections during prophylactic colonoscopy of 58 donors with no colon pathology. The mRNA levels for 62 genes involved in the regulation of apoptosis, proliferation, transcription, differentiation, cell-cell adhesion, and immune response were assessed by RT-PCR. Statistically significant differences were found for the molecular phenotypes of five sections of the colon. The results of the study can serve as a basis for creating a reference database (values of expression profiles), developing methods of differential diagnostics and screening of various pathologies of the colon.

Occupational exposure and risk of colon cancer: a nationwide registry study with emphasis on occupational exposure to zoonotic gastrointestinal pathogens

OBJECTIVES

While colon cancer (CC) risk is associated with several lifestyle-related factors, including physical inactivity, smoking and diet, the contribution of occupation to CC morbidity remains largely unclear. Growing evidence indicates that gastrointestinal infections like salmonellosis could contribute to CC development. We performed a nationwide registry study to assess potential associations between occupation (history) and CC, including also those occupations with known increased exposure to gastrointestinal pathogens like Salmonella. METHODS: Person-level occupational data for all residents in The Netherlands were linked to CC diagnosis data. Differences in the incidence of (overall, proximal and distal) CC among occupational sectors and risk groups were tested for significance by calculating standardised incidence ratios (SIRs) with 95% CIs using the general population as reference group. Effects of gender, age, exposure duration and latency were also assessed.

RESULTS

Significant differences in CC incidence were observed only for a few occupational sectors, including the manufacturing of rubber and plastics, machinery and leather, the printing sector and the information service sector (SIRs 1.06-1.88). No elevated risk of CC was observed among people with increased salmonellosis risk through occupational exposure to live animals, manure or among those working in the sale of animal-derived food products (SIRs 0.93-0.95, 0.81-0.95 and 0.93-1.09 for overall, proximal and distal CC, respectively).

CONCLUSIONS

The results of this study suggest that occupation in itself provides a relatively small contribution to CC incidence. This is consistent with previous studies where a similar degree of variation in risk estimates was observed. The lack of an association with the high-risk occupations for salmonellosis might be due to higher levels of physical activity, a known protective factor for CC and other diseases, of people working in the agricultural sector, which might outweigh the potential Salmonella-associated risk of CC.

MKK4 variants rs3826392 and rs3809728 are associated with susceptibility and clinicopathological features in colorectal cancer patients

OBJECTIVES

The mitogen-activated protein kinase kinase 4 (MKK4) plays a key role in several processes like inflammation, apoptosis, and tumorigenesis. Several authors have proposed that genetic variations in these genes may alter their expression with subsequent cancer risk. This study aimed to examine the possible association of MKK4 rs3826392 and rs3809728 variants in Mexican patients with colorectal cancer (CRC). These variants were also compared with clinical features as sex, age, TNM stage, and tumor location.

MATERIALS AND METHODS

The study included genomic DNA from 218 control subjects and 250 patients. Genotyping of the MKK4 variants was performed using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) procedure.

RESULTS

Individuals with A/T and T/T genotypes for the rs3809728 (-1044 A>T) variant showed a significantly increased risk for CRC (P=0.012 and 0.007, respectively); while individuals with the G/G genotype for the rs3826392 (-1304 T>G) variant showed a decreased risk for CRC (P=0.012). Genotypes of the MKK4 rs3809728 variant were also significantly related to colon localization and advanced TNM stage in CRC patients. T-T haplotype (rs3826392 and rs3809728) of the MKK4 gene was associated with risk in patients with CRC.

CONCLUSION

The rs3826392 variant in the MKK4 gene could be a cancer protective factor, while the rs3809728 variant could be a risk factor. These variants play a significant role in CRC risk.

Increasing colorectal cancer in the young population and tailoring of the colorectal cancer screening recommendations in subpopulation: a retrospective single-center study

PURPOSE

The United States Preventive Services Task Force (USPSTF) newly drafted recommendations for colorectal cancer (CRC) screening age in average-risk individuals decreased to 45 years from 50 years. This study evaluates the change in the incidence of CRC, compares the demographic characteristics, characteristics of CRC, survival, and factors affecting the survival of younger (< 50 years) with the older (> 50 years) CRC-diagnosed population of Boston Medical Center (BMC). Also tailors the screening recommendations of CRC based on subpopulations.

METHODS

A retrospective cohort study was conducted from 2004 to 2019 at BMC who underwent colonoscopy, to see newly diagnosed CRC. The analysis was done in R studio version 1.2.5033.

RESULTS

The incidence rate of CRC is increasing in the younger population. The CRC in younger population was 350 and older was 2019. The most prevalent site among the younger population was rectum (33.33%), and most of the CRC were diagnosed at an advanced stage. Hispanics were less likely to be diagnosed with CRC in older age group (OR= 0.468, 95% CI 0.285, 0.796). Lower BMI was associated with a higher risk of mortality (p= 0.012). There was no difference in survival in younger and older populations.

CONCLUSIONS

CRC is increasing in the younger population, and Hispanics are diagnosed with CRC usually at a younger age. Early screening in young populations with average risk and even earlier screening in high-risk populations like Hispanics is warranted for timely recognition for prevention, early management, and reduction of mortality.

Prognostic Score Model Based on Ten Differentially Methylated Genes for Predicting Clinical Outcomes in Patients with Adenocarcinoma of the Colon

Purpose

We aimed to screen novel genetic biomarkers for use in a prognostic score (PS) model for the accurate prediction of survival outcomes for patients with colon adenocarcinoma (COAD).

Methods

Gene expression and methylation data were downloaded from The Cancer Genome Atlas database, and the samples were randomly divided into training and validation sets for the screening of differentially methylated genes (DMGs) and differentially expressed genes (DEGs). Co-methylated genes were screened using weighted gene co-expression network analysis. Functional enrichment analysis was performed using the Database for Annotation, Visualization, and Integrated Discovery. Univariate and multivariate Cox regression analyses were performed to identify prognosis-related genes and clinical factors. Receiver operating characteristic curve analysis was carried out to evaluate the predictive performance of the PS model.

Results

In total, 1434 DEGs and 1038 DMGs were screened in the training set, among which 284 were found to be overlapping genes. For 127 of these overlapping genes, the methylation and expression levels were significantly negatively correlated. An optimal signature from 10 DMGs was identified to construct the PS model. Patients with a high PS seemed to have worse outcomes than those with a low PS. Moreover, cancer recurrence and the PS model status were independent prognostic factors.

Conclusion

This PS model based on an optimal 10-gene signature would help in the stratification of patients with COAD and improve the assessment of their clinical outcomes.

The influence of predictive nursing on the emotions and self-management abilities of post-colostomy rectal cancer patients

OBJECTIVE

This study aimed to explore the influence of predictive nursing on the emotions and self-management abilities of post-colostomy rectal cancer patients.

METHODS

From March 2017 to October 2019, 130 patients with rectal cancer were recruited as the study cohort and placed into a predictive group (the PG) (n=80) that underwent predictive nursing or a normal group (the NG) (n=50) that underwent routine nursing. After the intervention, the operative indications, self-care abilities, nutritional indicators, mental health, postoperative recovery, complications, and nursing satisfaction of the two groups were compared.

RESULTS

After the intervention, compared with the NG, the average blood loss, operation times, gastrointestinal tract recovery times and durations of the hospital stays in the PG were shorter, and the self-care ability scores were higher, the nutritional conditions, namely the albumin (ALB), transferrin (TRF), and prealbumin (PAB) levels, were higher, the mental health, namely the self-rating anxiety scale (SAS) and self-rating depression scale (SDS) scores, was better, the total effective rate of the postoperative recovery and the nursing satisfaction were higher, and the incidence of complications was lower.

CONCLUSION

predictive nursing can improve the moods and self-management abilities of post-colostomy rectal cancer patients.

Bromelain a Potential Bioactive Compound: A Comprehensive Overview from a Pharmacological Perspective

Bromelain is an effective chemoresponsive proteolytic enzyme derived from pineapple stems. It contains several thiol endopeptidases and is extracted and purified via several methods. It is most commonly used as an anti-inflammatory agent, though scientists have also discovered its potential as an anticancer and antimicrobial agent. It has been reported as having positive effects on the respiratory, digestive, and circulatory systems, and potentially on the immune system. It is a natural remedy for easing arthritis symptoms, including joint pain and stiffness. This review details bromelain's varied uses in healthcare, its low toxicity, and its relationship to nanoparticles. The door of infinite possibilities will be opened up if further extensive research is carried out on this pineapple-derived enzyme.

Analyzing non-cancer causes of death of colorectal carcinoma patients in the US population for the years 2000-2016

BACKGROUND

Colorectal cancer (CRC) treatment and patient survival improved greatly. Consequently an increased incidence of non-cancer-related deaths is observed. This study analyzed the causes of non-cancer death for people suffering from CRC based on the year of diagnosis, follow-up time, and patient's age.

METHODS

The data from patients diagnosed with CRC in the years 2000-2016 were taken from the Surveillance, Epidemiology, and End Results 18 database. Patients were categorized according to: death from CRC, non-CRC cancer, and non-cancer. Constituent ratios and standardized mortality ratios (SMRs) were calculated to describe the death causes distribution and relative death risks.

RESULTS

Between 2000 and 2016, a stable and rapid drop for the original diagnosis as death cause for CRC patients was observed (70.19% to 49.35%). This was coupled to an increase in non-cancer-associated death reasons (23.38% to 40.00%). The most common non-cancer death cause was heart disease, especially for elderly patients. However, deaths from accidents and adverse effects were frequent in younger CRC patients. Patients died from septicemia more often within the first follow-up year; however, a 6-fold increase in death from Alzheimer's disease was found for after at least 180 months follow-up time. The SMRs of all 25 non-cancer death causes initially decreased in all CRC subgroups, followed by an increase with follow-up times. Gradually decreasing SMR values were observed with increasing age of CRC patients.

CONCLUSIONS

These findings could help modify and sharpen preventive measures and clinical management and raise physician's awareness to potential non-CRC death risk factors for CRC patients.

Identification of a 5-Gene-Based Scoring System by WGCNA and LASSO to Predict Prognosis for Rectal Cancer Patients

Background

Although accumulating evidence suggested that a molecular signature panel may be more effective for the prognosis prediction than routine clinical characteristics, current studies mainly focused on colorectal or colon cancers. No reports specifically focused on the signature panel for rectal cancers (RC). Our present study was aimed at developing a novel prognostic signature panel for RC.

Methods

Sequencing (or microarray) data and clinicopathological details of patients with RC were retrieved from The Cancer Genome Atlas (TCGA-READ) or the Gene Expression Omnibus (GSE123390, GSE56699) database. A weighted gene coexpression network was used to identify RC-related modules. The least absolute shrinkage and selection operator analysis was performed to screen the prognostic signature panel. The prognostic performance of the risk score was evaluated by survival curve analyses. Functions of prognostic genes were predicted based on the interaction proteins and the correlation with tumor-infiltrating immune cells. The Human Protein Atlas (HPA) tool was utilized to validate the protein expression levels.

Results

A total of 247 differentially expressed genes (DEGs) were commonly identified using TCGA and GSE123390 datasets. Brown and yellow modules (including 77 DEGs) were identified to be preserved for RC. Five DEGs (ASB2, GPR15, PRPH, RNASE7, and TCL1A) in these two modules constituted the optimal prognosis signature panel. Kaplan-Meier curve analysis showed that patients in the high-risk group had a poorer prognosis than those in the low-risk group. Receiver operating characteristic (ROC) curve analysis demonstrated that this risk score had high predictive accuracy for unfavorable prognosis, with the area under the ROC curve of 0.915 and 0.827 for TCGA and GSE56699 datasets, respectively. This five-mRNA classifier was an independent prognostic factor. Its predictive accuracy was also higher than all clinical factor models. A prognostic nomogram was developed by integrating the risk score and clinical factors, which showed the highest prognostic power. ASB2, PRPH, and GPR15/TCL1A were predicted to function by interacting with CASQ2/PDK4/EPHA67, PTN, and CXCL12, respectively. TCL1A and GPR15 influenced the infiltration levels of B cells and dendritic cells, while the expression of PRPH was positively associated with the abundance of macrophages. HPA analysis supported the downregulation of PRPH, RNASE7, CASQ2, EPHA6, and PDK4 in RC compared with normal controls.

Conclusion

Our immune-related signature panel may be a promising prognostic indicator for RC.

Emerging Trends for Radio-Immunotherapy in Rectal Cancer

Rectal cancer is a heterogeneous disease at the genetic and molecular levels, both aspects having major repercussions on the tumor immune contexture. Whilst microsatellite status and tumor mutational load have been associated with response to immunotherapy, presence of tumor-infiltrating lymphocytes is one of the most powerful prognostic and predictive biomarkers. Yet, the majority of rectal cancers are characterized by microsatellite stability, low tumor mutational burden and poor T cell infiltration. Consequently, these tumors do not respond to immunotherapy and treatment largely relies on radiotherapy alone or in combination with chemotherapy followed by radical surgery. Importantly, pre-clinical and clinical studies suggest that radiotherapy can induce a complete reprograming of the tumor microenvironment, potentially sensitizing it for immune checkpoint inhibition. Nonetheless, growing evidence suggest that this synergistic effect strongly depends on radiotherapy dosing, fractionation and timing. Despite ongoing work, information about the radiotherapy regimen required to yield optimal clinical outcome when combined to checkpoint blockade remains largely unavailable. In this review, we describe the molecular and immune heterogeneity of rectal cancer and outline its prognostic value. In addition, we discuss the effect of radiotherapy on the tumor microenvironment, focusing on the mechanisms and benefits of its combination with immune checkpoint inhibitors.

CXCL11 Correlates With Antitumor Immunity and an Improved Prognosis in Colon Cancer

The chemokine ligand C-X-C motif chemokine ligand 11 (CXCL11) is involved in the progression of various cancers, but its biological roles in colorectal cancer (CRC) remain confused. Therefore, the prognostic value and underlying mechanism of CXCL11 in CRC were preliminarily evaluated. Three independent datasets were used for mRNA-related analysis: one dataset from the Cancer Genome Atlas (TCGA, n = 451) and two single-cell RNA sequencing (scRNA-seq) datasets from Gene Expression Omnibus (GEO): GSE146771 and GSE132465. In addition, a colon adenocarcinoma (COAD) patient cohort (the Yijishan Hospital cohort, YJSHC, n = 108) was utilized for analysis of cell infiltration by immunohistochemistry. We determined the distribution of CXCL11 in tumor tissue across all TCGA cancers and found that CXCL11 expression was significantly upregulated in both COAD and rectal adenocarcinoma (READ). However, the upregulation of CXCL11 mRNA was associated with a better prognosis in COAD, but not in READ. Within the YJSHC, the patients with a high abundance of intratumoral CXCL11⁺ cells had prolonged survival (p = 0.001). Furthermore, we found that the high CXCL11 expression group had a higher proportion of antitumor immune cells, and a lower proportion of protumor immune cells. Additionally, we discovered the changes of gene expression and enriched immune pathway network mediated by CXCL11. Interestingly, both cytotoxic genes (IFNG, GZMA, GZMB, GZMK, GZMM, and PRF1) and immunosuppressive molecules, including PD-L1, were positively correlated with CXCL11 expression. CXCL11, which promoted antitumor immunity to benefit survival, was identified as an independent prognostic biomarker in patients with COAD.

Fibrotic Phenotype of Peritumour Mesenteric Adipose Tissue in Human Colon Cancer: A Potential Hallmark of Metastatic Properties

The impact of tumour associated stroma on cancer metastasis is an emerging field. However, cancer associated genes in peritumoral adipose tissue (pAT) in human colon cancer have not been explored. The aim of this study was to identify differentially expressed genes (DEGs) associated with cancer pathways in mesenteric pAT compared with adjacent adipose tissue. In total, nine patients with colon cancer pathological stage T2/T4 were employed in this study. DEGs were identified in 6 patients employing Nanostring PanCancer Pathway Panel and pathway enrichment analyses were performed. Differential expression of the 5 most up-regulated and 2 down regulated genes was validated with qRT-PCR. Results showed collagen type I alpha 1 chain (COL1A1) p = 0.007; secreted frizzled related protein (SFRP2) p = 0.057; fibroblast growth factor 7 (FGF7) not significant (ns); phospholipase A2, group IIA (PLA2G2A) ns; nerve growth factor receptor (NGFR) ns; lymphoid enhancer binding factor 1 (LEF1) p = 0.03; cadherin 1, Type 1, E-cadherin (epithelial) (CDH1) 0.09. Results have highlighted down-regulation of the Wingless/Integrated (Wnt) pathway in mesenteric pAT compared to distal adipose tissue. Highly upregulated genes in mesenteric pAT were involved in extracellular matrix (ECM)-receptor interactions and focal adhesion. Highly down regulated genes were involved in the cell cycle. Immunohistochemistry revealed differential distribution of COL1A1 showing maximum levels in tumour tissue and gradually decreasing in distant adipose tissue. COL1A1 and down regulation of Wnt pathway may have a role in local invasion and distant metastasis. COL1A1 may represent a stromal prognostic biomarker and therapeutic target in colon cancer.

Effects of the Novel PFKFB3 Inhibitor KAN0438757 on Colorectal Cancer Cells and Its Systemic Toxicity Evaluation In Vivo

BACKGROUND

Despite substantial progress made in the last decades in colorectal cancer (CRC) research, new treatment approaches are still needed to improve patients' long-term survival. To date, the promising strategy to target tumor angiogenesis metabolically together with a sensitization of CRC to chemo- and/or radiotherapy by PFKFB3 (6-phosphofructo-2-kinase/fructose-2,6-biphosphatase-3) inhibition has never been tested. Therefore, initial evaluation and validation of newly developed compounds such as KAN0438757 and their effects on CRC cells are crucial steps preceding to in vivo preclinical studies, which in turn may consolidate new therapeutic targets.

MATERIALS AND METHODS

The efficiency of KAN0438757 to block PFKFB3 expression and translation in human CRC cells was evaluated by immunoblotting and real-time PCR. Functional in vitro assays assessed the effects of KAN0438757 on cell viability, proliferation, survival, adhesion, migration and invasion. Additionally, we evaluated the effects of KAN0438757 on matched patient-derived normal and tumor organoids and its systemic toxicity in vivo in C57BL6/N mice.

RESULTS

High PFKFB3 expression is correlated with a worse survival in CRC patients. KAN0438757 reduces PFKFB3 protein expression without affecting its transcriptional regulation. Additionally, a concentration-dependent anti-proliferative effect was observed. The migration and invasion capacity of cancer cells were significantly reduced, independent of the anti-proliferative effect. When treating colonic patient-derived organoids with KAN0438757 an impressive effect on tumor organoids growth was apparent, surprisingly sparing normal colonic organoids. No high-grade toxicity was observed in vivo.

CONCLUSION

The PFKFB3 inhibitor KAN0438757 significantly reduced CRC cell migration, invasion and survival. Moreover, on patient-derived cancer organoids KAN0438757 showed significant effects on growth, without being overly toxic in normal colon organoids and healthy mice. Our findings strongly encourage further translational studies to evaluate KAN0438757 in CRC therapy.

A Prognostic Nomogram of Colon Cancer With Liver Metastasis: A Study of the US SEER Database and a Chinese Cohort

Background

Among colon cancer patients, liver metastasis is a commonly deadly phenomenon, but there are few prognostic models for these patients.

Methods

The clinicopathologic data of colon cancer with liver metastasis (CCLM) patients were downloaded from the Surveillance, Epidemiology and End Results (SEER) database. All patients were randomly divided into training and internal validation sets based on the ratio of 7:3. A prognostic nomogram was established with Cox analysis in the training set, which was validated by two independent validation sets.

Results

A total of 5,700 CCLM patients were included. Age, race, tumor size, tumor site, histological type, grade, AJCC N status, carcinoembryonic antigen (CEA), lung metastasis, bone metastasis, surgery, and chemotherapy were independently associated with the overall survival (OS) of CCLM in the training set, which were used to establish a nomogram. The AUCs of 1-, 2- and 3-year were higher than or equal to 0.700 in the training, internal validation, and external validation sets, indicating the favorable effects of our nomogram. Besides, whether in overall or subgroup analysis, the risk score calculated by this nomogram can divide CCLM patients into high-, middle- and low-risk groups, which suggested that the nomogram can significantly determine patients with different prognosis and is suitable for different patients.

Conclusion

Higher age, the race of black, larger tumor size, higher grade, histological type of mucinous adenocarcinoma and signet ring cell carcinoma, higher N stage, RCC, lung metastasis, bone metastasis, without surgery, without chemotherapy, and elevated CEA were independently associated with poor prognosis of CCLM patients. A nomogram incorporating the above variables could accurately predict the prognosis of CCLM.

Long-term oncological outcomes of low anterior resection for rectal cancer with and without preservation of the left colic artery: a retrospective cohort study

Background

There is uncertainty in the literature about preserving the left colic artery (LCA) during low anterior resection for rectal cancer. We analyzed the effect of preserving the LCA on long-term oncological outcomes.

Methods

We retrospectively collected clinicopathological and follow-up details of patients who underwent low anterior resection for rectal cancer in the General Surgery Department of Guangdong Provincial People’s Hospital, from January 2014 to December 2015. Cases were divided into low ligation (LL), LCA preserved, or high ligation (HL), LCA not preserved, of the inferior mesenteric artery. The 5-year overall survival (OS) and disease-free survival (DFS) rates were compared between the two groups.

Results

Altogether, there were 221 and 295 cases in the LL group and HL groups, respectively. Operating time in the LL group was significantly longer than in the HL group (224.7 vs. 211.7 min, p = 0.039). Postoperative 30-day mortality, early complications including anastomotic leakage showed no significant differences between the LL and HL groups (postoperative 30-day mortality, 0.9% LL, 1.4% HL, p = 0.884; early complications, 41.2% LL, 38.3% HL, p = 0.509; anastomotic leakage 8.6% LL, 13.2% HL, p = 0.100). The median follow-up periods were 51.4 (7–61) months in the LL group and 51.2 (8–61) months in the HL group. During follow-up, the percentages of patients who died, had local recurrence, or had metastases were 39.8, 7.7, and 38.5%, respectively, in the LL group and 39, 8.5, and 40%, respectively, in the HL group; these differences were not significant (all p > 0.05). The 5-year OS and DFS were 69.6 and 59.6% in the LL group, respectively, and 69.1 and 56.2% in the HL group, respectively; these differences were not significant (all p > 0.05). After stratification by tumor-node-metastasis stage, the difference between the 5-year OS and DFS for stages I, II, and III cancer were not significant (all p > 0.05).

Conclusions

The long-term oncological outcomes of LL group are comparable with HL group. LL cannot be supported due to the absence of lower complication rates and the longer operating times.

Single-Cell Analysis Reveals Characterization of Infiltrating T Cells in Moderately Differentiated Colorectal Cancer

Objective

This study aimed to characterize the tumor-infiltrating T cells in moderately differentiated colorectal cancer.

Methods

Using single-cell RNA sequencing data of isolated 1632 T cells from tumor tissue and 1252 T cells from the peripheral blood of CRC patients, unsupervised clustering analysis was performed to identify functionally distinct T cell populations, followed by correlations and ligand-receptor interactions across cell types. Finally, differential analysis of the tumor-infiltrating T cells between colon cancer and rectal cancer were carried out.

Results

A total of eight distinct T cell populations were identified from tumor tissue. Tumor-Treg showed a strong correlation with Th17 cells. CD8⁺T_RM was positively correlated with CD8⁺IEL. Seven distinct T cell populations were identified from peripheral blood. There was a strong correlation between CD4+T_N and CD4+blood-T_CM. Colon cancer and rectal cancer showed differences in the composition of tumor-infiltrating T cell populations. Tumor-infiltrating CD8⁺IEL cells were found in rectal cancer but not in colon cancer, while CD8⁺ T_N cells were found in the peripheral blood of colon cancer but not in that of rectal cancer. A larger number of tumor-infiltrating CD8⁺ Tex (88.94%) cells were found in the colon cancer than in the rectal cancer (11.06%). The T cells of the colon and rectal cancers showed changes in gene expression pattern.

Conclusions

We characterized the T cell populations in the CRC tumor tissue and peripheral blood.

Three dimensional cultivation increases chemo- and radioresistance of colorectal cancer cell lines

Although 2D cell cultures are commonly used to predict therapy response, it has become clear that 3D cultures may better mimic the in vivo situation and offer the possibility of tailoring translational clinical approaches. Here, we compared the response of 2D and 3D colorectal cancer (CRC) cell lines to irradiation and chemotherapy. Classic 2D cultures and 3D spheroids of CRC cell lines (CaCo2, Colo205, HCT116, SW480) were thoroughly established, then irradiated with doses of 1, 4, or 10 Gy, using a clinical-grade linear accelerator. The response was assessed by immunohistochemistry, flow cytometry, and TUNEL assays. Upon irradiation, CRC 3D spheroids were morphologically altered. After irradiation with 10 Gy, annexin V/PI staining revealed a 1.8- to 4-fold increase in the apoptosis rate in the 2D cell cultures (95% CI 3.24±0.96), and a 1.5- to 2.4-fold increase in the 3D spheroids (95% CI 1.56±0.41). Irradiation with 1 Gy caused 3- and 4-fold increases in TUNEL positive cells in the CaCo2 and HCT116 (p = 0.01) 2D cultures, respectively, compared with a 2-fold increase in the 3D spheroids. Furthermore, the 2D and 3D cultures responded differently to chemotherapy; the 3D cultures were more resistant to 5-FU and cisplatin, but not to doxorubicin and mitomycin C, than the 2D cultures. Taken together, CRC cells cultured as 3D spheroids displayed markedly higher resistance to irradiation therapy and selected chemotherapeutic drugs than 2D cultures. This in vitro difference must be considered in future approaches for determining the ideal in vitro systems that mimic human disease.

The mutational pattern of homologous recombination-related (HRR) genes in Chinese colon cancer and its relevance to immunotherapy responses

BACKGROUND

Microsatellite-stable (MSS) colon adenocarcinoma (COAD) patients are not sensitive to immune checkpoint inhibitors. Here, we focused on analyzing the relationship between homologous recombination repair (HRR)-related gene mutations and clinical immunotherapy responses in MSS COAD.

METHODS

The mutational landscape was profiled in a cohort of 406 Chinese COAD patients via next-generation sequencing (NGS). Correlations between HRR gene mutations and tumor immunity or clinical outcomes in two COAD genomic datasets were analyzed via bioinformatics.

RESULTS

In the Chinese cohort, seventy (17%) patients exhibited genomic alterations in HRR genes; ATM (9%), BRCA2 (4%), ATR (3%), RAD50 (3%) and BRIP1 (3%) were the most frequently mutated. In the MSK-IMPACT COAD cohort (immune checkpoint inhibitor-treated), HRR-mut patients (n=34) survived longer than HRR-wt patients (n=50) (log-rank P < 0.01). Based on the TCGA MSS COAD cohort, HRR gene mutations increased immune activities, such as infiltration of cytotoxic cells (P < 0.05) and exhausted CD8+ T cells (P < 0.01), and increased the IFN-γ scores (P < 0.05). The results differed in MSI-H COAD patients (all P > 0.05).

CONCLUSION

HRR gene mutations significantly increased immune activities in MSS COAD patients, implying the feasibility of the HRR-mut status as an immunotherapy response predictor in MSS COAD.

Is tumor testing efficiency for Lynch syndrome different in rectal and colon cancer?

BACKGROUND

Tumor testing utility in Lynch syndrome (LS) diagnosis is established.

AIMS

Analyze the differences between tumor testing efficiency in rectal (RC) and colon cancer (CC).

METHODS

We performed immunohistochemistry (IHC) for MisMatch Repair (MMR) proteins (IHC-MMR) and MicroSatellite Instability analysis (MSI) on 482 unselected primary tumors: 320 CCs and 162 RCs. Samples had proficient-IHC, deficient-IHC or borderline-IHC ("patchy" expression). MSI-H borderline-IHC tumors were considered as likely MMR-deficient. Germline testing was offered to MMR-deficient patients without BRAF mutation or MLH1 promoter hypermetilation (MLH1-Hy).

RESULTS

We identified 51/482 (10.6%) MMR-defective tumors. Multivariable analysis demonstrated a significant correlation between tumor testing results with histotype, lymph-node involvement and tumor location. In particular, RC showed a lower MMR-deficiency rate than CC (p<0.0001). Interestingly, MLH1 loss was detected in 0% RCs and 76.1% CCs, with 80% of them showing BRAF mutation/MLH1-Hy. A germline variant was detected in 12 out of 18 patients (mutation detection rate of 66.7%).

CONCLUSION

Tumor testing results showed molecular differences between CCs and RCs, in terms of MMR proteins expression, and presence of BRAF mutation/MLH1-Hy. MSH6 variants were the most frequent ones (50%). Although young age at diagnosis was associated with mutation detection (p = 0.045), 33.3% of LS patients were >50 years.

Tumor-Associated Macrophages in Human Breast, Colorectal, Lung, Ovarian and Prostate Cancers

Tumor-associated macrophages (TAMs) are major innate immune cells that constitute up to 50% of the cell mass of human tumors. TAMs are highly heterogeneous cells that originate from resident tissue-specific macrophages and from newly recruited monocytes. TAMs' variability strongly depends on cancer type, stage, and intratumor heterogeneity. Majority of TAMs are programmed by tumor microenvironment to support primary tumor growth and metastatic spread. However, TAMs can also restrict tumor growth and metastasis. In this review, we summarized the knowledge about the role of TAMs in tumor growth, metastasis and in the response to cancer therapy in patients with five aggressive types of cancer: breast, colorectal, lung, ovarian, and prostate cancers that are frequently metastasize into distant organs resulting in high mortality of the patients. Two major TAM parameters are applied for the evaluation of TAM correlation with the cancer progression: total amount of TAMs and specific phenotype of TAMs identified by functional biomarkers. We summarized the data generated in the wide range of international patient cohorts on the correlation of TAMs with clinical and pathological parameters of tumor progression including lymphatic and hematogenous metastasis, recurrence, survival, therapy efficiency. We described currently available biomarkers for TAMs that can be measured in patients' samples (tumor tissue and blood). CD68 is the major biomarker for the quantification of total TAM amounts, while transmembrane receptors (stabilin-1, CD163, CD206, CD204, MARCO) and secreted chitinase-like proteins (YKL-39, YKL-40) are used as biomarkers for the functional TAM polarization. We also considered that specific role of TAMs in tumor progression can depend on the localization in the intratumoral compartments. We have made the conclusion for the role of TAMs in primary tumor growth, metastasis, and therapy sensitivity for breast, colorectal, lung, ovarian, and prostate cancers. In contrast to other cancer types, majority of clinical studies indicate that TAMs in colorectal cancer have protective role for the patient and interfere with primary tumor growth and metastasis. The accumulated data are essential for using TAMs as biomarkers and therapeutic targets to develop cancer-specific immunotherapy and to design efficient combinations of traditional therapy and new immunomodulatory approaches.

CD44 Genotypes Are Associated with Susceptibility and Tumor Characteristics in Colorectal Cancer Patients

Colorectal cancer is the third cause of cancer and the second leading cause of death worldwide. The CD44 gene plays a key role in malignant processes, including growth, survival, epithelial to mesenchymal transition and metastasis. It is also known that some variants as rs187116 (c.67+4883G>A) and rs7116432 (c.2024+779A>G) can modulate the function of the CD44 gene and malignant transformation in several neoplasms. This study aims to explore, for the first time, the association of the CD44 rs187116 and rs7116432 variants in patients with colorectal cancer. Genomic DNA from 250 patients and 250 healthy blood donors were analyzed. The identification of variants was made by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) methodology. Association was calculated by the odds ratio (OR) test and multivariate analysis. Individuals carrying the G/A and A/A genotypes for the rs187116 polymorphism showed an increased risk for colorectal cancer (OR = 3.11, 95% CI: 1.87-5.16, P = 0.001 and OR = 3.59, 95% CI: 2.06-6.25, P = 0.001, respectively). After adjusting for age and gender, these same genotypes and the G/G genotype of the rs7116432 polymorphism were associated with TNM stage and tumor location in the colon. Moreover, the A-G (rs187116 and rs7116432) haplotype was associated with increased risk; while, the haplotype G-A (rs187116 and rs7116432) was related with decreased risk. In conclusion, our results suggest that the here analyzed CD44 variants are involved with risk, TNM stage and tumor location in colorectal cancer.

Genome-wide DNA methylation analysis by MethylRad and the transcriptome profiles reveal the potential cancer-related lncRNAs in colon cancer

Colon cancer (CC) is characterized by global aberrant DNA methylation that may affect gene expression and genomic stability. A series of studies have demonstrated that DNA methylation could regulate the expressions of not only protein-coding genes but also ncRNAs. However, the regulatory role of lncRNA genes methylaton in CC remains largely unknown. In the present study, we systemically characterize the profile of DNA methylation, especially the aberrant methylation of lncRNAs genes using MethylRAD technology. A total of 132 999 CCGG/8487 CCWGG sites were identified as differentially methylated sites (DMSs), which were mainly located on the introns and intergenic elements. Moreover, 1,359 CCGG/1,052 CCWGG differentially methylated genes (DMGs) were screened. Our results demonstrated that aberrant methylation of lncRNA genes occurred most frequently, accounting for 37.5% and 44.3% in CCGG and CCWGG DMGs respectively. In addition, 963 lncRNA DMGs were co-analyzed with 1328 differentially expressed lncRNAs which were identified from TCGA database. We found that 15 lncRNAs might be CC-related lncRNAs. ZNF667-AS1 and MAFA-AS1 were down-regulated in CC, which might be silenced by hypermethylation. Besides, 13 lncRNAs were hypomethylated and up-regulated in CC. Moreover, our results validated the expression and methylation level of CC-related lncRNAs by RT-qPCR and pyrosequencing assay. In conclusion, we performed a genome-wide DNA methylation analysis by MethylRAD to acquire both CCGG and CCWGG DMSs and DMGs in CC. The results screened lncRNA DMSs as potential biomarkers and identified 15 lncRNAs as CC-related lncRNAs. This study provided novel therapy targets and valuable insights into molecular mechanism in tumorigenesis and development of CC.

Obesity Has a Stronger Relationship with Colorectal Cancer in Postmenopausal Women than Premenopausal Women

BACKGROUND

To examine the relationship between obesity measured by waist circumference (WC) and body mass index (BMI) and the incidence of colorectal cancer in premenopausal and postmenopausal women.

METHODS

A total of 1,418,180 premenopausal and 4,854,187 postmenopausal women without cancer at baseline and ages over 40 were identified using the Korean National Health Insurance System Cohort during 2009 to 2014. The hazard ratio (HR) for colorectal cancer incidence was assessed according to menopausal state using Cox proportional hazards models.

RESULTS

During a mean follow-up period of 7.2 years, 7,094 and 57,449 colorectal cancer cases occurred in premenopausal and postmenopausal women, respectively. Compared with the reference group (WC 65-75), the HRs [95% confidence interval (CI)] of colorectal cancer in WC <65, 75-85, 85-95, and >95 groups were 1.01 (0.91-1.11), 1.02 (0.97-1.07), 1.09 (1.00-1.18), and 1.31 (1.12-1.52), respectively, in premenopausal women and 1.01 (0.95-1.17), 1.09 (1.07-1.12), 1.19 (1.00-1.18), and 1.30 (1.25-1.35), respectively, in postmenopausal women. Compared with the reference group (BMI 18.5-22.9), HRs (95% CI) for colorectal cancer in BMI <18.5, 23-25, 25-30, and >30 groups were 0.99 (0.87-1.14), 0.99 (0.94-1.06), 0.98 (0.92-1.04), and 1.06 (0.92-1.20), respectively, in premenopausal women. In postmenopausal women, those values were 0.99 (0.93-1.05), 1.05 (1.03-1.08), 1.11 (1.09-1.13), and 1.20 (1.16-1.25), respectively.

CONCLUSIONS

WC is associated with the risk of colorectal cancer in both groups of women, but this association was stronger in postmenopausal women than in premenopausal women. BMI increased the incidence of colorectal cancer only in postmenopausal women IMPACT: Obesity has a stronger relationship with colorectal cancer in postmenopausal women than in premenopausal women.

Comparative Study of Organoids from Patient-Derived Normal and Tumor Colon and Rectal Tissue

Colon and rectal tumors, often referred to as colorectal cancer, show different gene expression patterns in studies that analyze whole tissue biopsies containing a mix of tumor and non-tumor cells. To better characterize colon and rectal tumors, we investigated the gene expression profile of organoids generated from endoscopic biopsies of rectal tumors and adjacent normal colon and rectum mucosa from therapy-naive rectal cancer patients. We also studied the effect of vitamin D on these organoid types. Gene profiling was performed by RNA-sequencing. Organoids from a normal colon and rectum had a shared gene expression profile that profoundly differed from that of rectal tumor organoids. We identified a group of genes of the biosynthetic machinery as rectal tumor organoid-specific, including those encoding the RNA polymerase II subunits POLR2H and POLR2J. The active vitamin D metabolite 1α,25-dihydroxyvitamin D3/calcitriol upregulated stemness-related genes (LGR5, LRIG1, SMOC2, and MSI1) in normal rectum organoids, while it downregulated differentiation marker genes (TFF2 and MUC2). Normal colon and rectum organoids share similar gene expression patterns and respond similarly to calcitriol. Rectal tumor organoids display distinct and heterogeneous gene expression profiles, with differences with respect to those of colon tumor organoids, and respond differently to calcitriol than normal rectum organoids.

Inflammatory potential of the diet and risk of colorectal cancer in the European Prospective Investigation into Cancer and Nutrition study

Proinflammatory diets are associated with risk of developing colorectal cancer (CRC), however, inconsistencies exist in subsite- and sex-specific associations. The relationship between CRC and combined lifestyle-related factors that contribute toward a low-grade inflammatory profile has not yet been explored. We examined the association between the dietary inflammatory potential and an inflammatory profile and CRC risk in the European Prospective Investigation into Cancer and Nutrition (EPIC) study. This cohort included 476,160 participants followed-up of 14 years and 5,991 incident CRC cases (3,897 colon and 2,094 rectal tumors). Dietary inflammatory potential was estimated using an Inflammatory Score of the Diet (ISD). An Inflammatory Profile Score (IPS) was constructed, incorporating the ISD, physical activity level and abdominal obesity. The associations between the ISD and CRC and IPS and CRC were assessed using multivariable regression models. More proinflammatory diets were related to a higher CRC risk, particularly for colon cancer; hazard ratio (HR) for highest versus lowest ISD quartile was 1.15 (95% confidence interval [CI] 1.04-1.27) for CRC, 1.24 (95% CI 1.09-1.41) for colon cancer and 0.99 (95% CI 0.83-1.17) for rectal cancer. Associations were more pronounced in men and not significant in women. The IPS was associated with CRC risk, particularly colon cancer among men; HRs for the highest versus lowest IPS was 1.62 (95% CI 1.31-2.01) for colon cancer overall and 2.11 (95% CI 1.50-2.97) for colon cancer in men. Our study shows that more proinflammatory diets and a more inflammatory profile are associated with higher risk of CRC, principally colon cancer and in men.

Early-onset colorectal cancer: initial clues and current views

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

Is There an Optimal Choice in Refractory Colorectal Cancer? A Network Meta-Analysis

BACKGROUND

In the absence of head-to-head comparison studies, the present network meta-analysis evaluated and compared the efficacy of 4 therapeutic alternatives for refractory colorectal cancer.

MATERIALS AND METHODS

The search focused on results from phase III randomized controlled trials. Separate (subgroup) network meta-analyses were conducted to obtain drug comparisons stratified by various patient characteristics. The principal outcome of interest was overall survival (OS).

RESULTS

No difference in OS was found between regorafenib and TAS-102. For a rectal primary location, TAS-102 conferred benefit versus placebo (hazard ratio [HR], 0.671), but regorafenib did not (HR, 0.950). For patients aged > 65 years, TAS-102 showed benefit versus placebo (HR, 0.579) but regorafenib did not (HR, 0.816). For patients with an Eastern Cooperative Oncology Group (ECOG) performance status (PS) of 0 in the indirect comparison, regorafenib showed benefit versus placebo (HR, 0.687), as did TAS-102 (HR, 0.756) but with a lower advantage. For patients with RAS wild type not previously treated with anti-EGFR antibodies, panitumumab was the optimal choice for OS.

CONCLUSIONS

No differences in OS were found between regorafenib and TAS-102. Possible greater efficacy was found for TAS-102 compared with regorafenib for patients with a rectal primary location, ECOG PS > 0, and age > 65 years. In contrast, regorafenib showed possible greater effectiveness for patients with ECOG PS 0 and age < 65 years. In the RAS WT population, the anti-EGFR drug showed superiority with respect to TAS-102 and regorafenib. These results should be viewed as only exploratory, and further prospective studies are warranted to validate these data.

Construction of an Immunogenomic Risk Score for Prognostication in Colon Cancer

Immune-related genes (IRGs) play regulatory roles in the immune system and are involved in the initiation and progression of colon cancer. This study aimed to develop an immunogenomic risk score for predicting survival outcomes among colon cancer patients. We analyzed the expressions of IRGs in colon specimens and discovered 484 differentially expressed IRGs when we compared specimens from colon cancer and adjacent normal tissue. Univariate Cox regression analyses were performed to identify 26 IRGs that were associated with survival. A Cox proportional hazards model with a lasso penalty identified five optimal IRGs for constructing the immunogenomic risk score (CD1B, XCL1, PLCG2, NGF, and OXTR). The risk score had good performance in predicting overall survival among patients with colon cancer and was correlated with the amount of tumor-infiltrating immune cells. Our findings suggest that the immunogenomic risk score may be useful for prognostication in colon cancer cases. Furthermore, the five IRGs included in the risk score might be useful targets for investigating the initiation of colon cancer and designing personalized treatments.

Long Noncoding RNA MALAT1 Promotes the Development of Colon Cancer by Regulating miR-101-3p/STC1 Axis

Purpose

Colon cancer (CC) is a leading cause of cancer-related deaths worldwide. This study aimed to clarify the effect of long noncoding RNA (lncRNA) metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) on CC progression and the potential mechanism.

Methods

CC cell lines HCT116 and HT29 were selected for functional analysis. The expression of MALAT1, microRNA (miR)-101-3p, and stanniocalcin 1 (STC1) in CC tissues and cells were measured by quantitative reverse transcription PCR (qRT-PCR). Cell proliferation, apoptosis, migration and invasion were measured by Cell Counting Kit-8 (CCK-8), flow cytometry, wound scratch and transwell assay, respectively. The target relationships (MALAT1 and miR-101-3p, miR-101-3p and STC1) were validated by dual-luciferase reporter and RNA pull-down assay.

Results

The expression of MALAT1 was elevated in CC tissues compared with adjacent normal tissues and was associated with lymph node metastasis, depth of invasion and tumor-node-metastasis (TNM) stage. Up-regulation of MALAT1 promoted the proliferation, migration, and invasion and inhibited the apoptosis of CC cells; while MALAT1 knockdown exhibited opposite results. MiR-101-3p was a target of MALAT1, which was negatively regulated by MALAT1. Silencing of miR-101-3p reverses the anti-tumor effect of MALAT1 knockdown on CC cells. STC1 was a target of miR-101-3p, which was negatively regulated by miR-101-3p. Silencing of STC1 reverses the tumor promoting effects of MALAT1 up-regulation and miR-101-3p down-regulation on CC cells.

Conclusion

MALAT1 may function as an oncogene in CC progression by affecting the miR-101-3p/STC1 axis, providing a hopeful therapeutic option for CC.

A meta-analysis of serological thymidine kinase 1 as a marker for colorectal benign and malignant tumor risk assessment

The present study investigated whether a concentration of serum thymidine kinase 1 (STK1p) could be used to distinguish between healthy individuals, patients with colorectal benign tumors and individuals with colorectal cancer (CRC). The effectiveness of surgery on patients with CRC was monitored. A total of 20 publications containing patients with CRC (n=1,836), patients with colorectal benign tumors (n=774) and healthy controls (n=1,701) were analysed in the present meta-analysis. The publications were collected from PubMed, Embase, CENTRAL, CNKI, Wanfang, VIP and SinoMed databases from January 1, 2009 until August 31, 2019. Articles were analyzed according to sensitivity (Forest plot) and publication bias (Begg's plot, Egger's linear regression) using fixed or random effect models to calculate the weighted mean difference. Study quality was checked using the Newcastle-Ottawa Scale Document Quality Assessment Scale. The meta-analysis followed the PRISMA statement. The results revealed that STK1p significantly distinguished healthy individuals and those with colorectal benign tumors from patients with CRC, and from patients with benign tumors (P<0.000001). STK1p levels also decreased by 40% following surgery (P<0.0001), which corresponded to half-life of ~1 month. The quality of the present study was high and no bias was identified among publication. It was concluded that STK1p was a reliable biomarker for the early detection of benign lesions, which may therefore prevent their future development into colorectal malignancies. STK1p may also be used for the clinical dynamic monitoring of the effectiveness of surgery in patients with CRC. Combining STK1p with colorectal-associated biomarkers, in addition to the determination of tumor stage and grade may therefore be of use.

Dietary natural methylxanthines and colorectal cancer: a systematic review and meta-analysis

Some evidence suggests that caffeine, theophylline, and theobromine, as natural methylxanthines (MTXs), possess anti-cancer effects.

Tumor sidedness influences prognostic impact of lymph node metastasis in colon cancer patients undergoing curative surgery

This study aimed to evaluate prognostic impacts of the number of lymph nodes (LNs) examined and LN ratio on cancer-specific mortality after surgery in patients with right-sided colon cancer (RCC) or left-sided colon cancer (LCC) using the Surveillance, Epidemiology, and End Results database. Number of LNs examined and LN ratio were treated as categorical and/or continuous. Competing risks proportional hazards regressions adjusted by propensity score were performed. All included patients had stage I, II, or III disease, and 45.1% of them had RCC. RCC and LCC patients with high level of LNs examined had better prognosis after segmental resection or hemicolectomy. RCC and LCC patients with higher LN ratio had worse prognosis regardless of surgery. Survival benefit of having high level of LNs examined was observed in RCC patients with stage I, II, or III disease, but only in LCC patients with stage II disease. Both higher LN ratio and high level of LN were negative prognostic factors for cancer-specific mortality in stage III patients regardless of tumor sidedness. In conclusion, RCC patients in various conditions had worse or comparable prognosis compared to their LCC counterparts, which reflected the severity of LN metastasis.

DNA methylation instability by BRAF-mediated TET silencing and lifestyle-exposure divides colon cancer pathways

Background

Aberrations in DNA methylation are widespread in colon cancer (CC). Understanding origin and progression of DNA methylation aberrations is essential to develop effective preventive and therapeutic strategies. Here, we aimed to dissect CC subtype-specific methylation instability to understand underlying mechanisms and functions.

Methods

We have assessed genome-wide DNA methylation in the healthy normal colon mucosa (HNM), precursor lesions and CCs in a first comprehensive study to delineate epigenetic change along the process of colon carcinogenesis. Mechanistically, we used stable cell lines, genetically engineered mouse model of mutant BRAF^V600E and molecular biology analysis to establish the role of BRAF^V600E-mediated-TET inhibition in CpG-island methylator phenotype (CIMP) inititation.

Results

We identified two distinct patterns of CpG methylation instability, determined either by age–lifestyle (CC-neutral CpGs) or genetically (CIMP-CpGs). CC-neutral-CpGs showed age-dependent hypermethylation in HNM, all precursors, and CCs, while CIMP-CpGs showed hypermethylation specifically in sessile serrated adenomas/polyps (SSA/Ps) and CIMP-CCs. BRAF^V600E-mutated CCs and precursors showed a significant downregulation of TET1 and TET2 DNA demethylases. Stable expression of BRAF^V600E in nonCIMP CC cells and in a genetic mouse model was sufficient to repress TET1/TET2 and initiate hypermethylation at CIMP-CpGs, reversible by BRAF^V600E inhibition. BRAF^V600E-driven CIMP-CpG hypermethylation occurred at genes associated with established CC pathways, effecting functional changes otherwise achieved by genetic mutation in carcinogenesis.

Conclusions

Hence, while age–lifestyle-driven hypermethylation occurs generally in colon carcinogenesis, BRAF^V600E-driven hypermethylation is specific for the “serrated” pathway. This knowledge will advance the use of epigenetic biomarkers to assess subgroup-specific CC risk and disease progression.

Newly Developed CK1-Specific Inhibitors Show Specifically Stronger Effects on CK1 Mutants and Colon Cancer Cell Lines

Protein kinases of the CK1 family can be involved in numerous physiological and pathophysiological processes. Dysregulated expression and/or activity as well as mutation of CK1 isoforms have previously been linked to tumorigenesis. Among all neoplastic diseases, colon and rectal cancer (CRC) represent the fourth leading cause of cancer related deaths. Since mutations in CK1δ previously found in CRC patients exhibited increased oncogenic features, inhibition of CK1δ is supposed to have promising therapeutic potential for tumors, which present overexpression or mutations of this CK1 isoform. Therefore, it is important to develop new small molecule inhibitors exhibiting higher affinity toward CK1δ mutants. In the present study, we first characterized the kinetic properties of CK1δ mutants, which were detected in different tumor entities. Subsequently, we characterized the ability of several newly developed IWP-based inhibitors to inhibit wild type and CK1δ mutants and we furthermore analyzed their effects on growth inhibition of various cultured colon cancer cell lines. Our results indicate, that these compounds represent a promising base for the development of novel CRC therapy concepts.

Mediterranean diet adherence and risk of colorectal cancer: the prospective Netherlands Cohort Study

Mediterranean diet (MD) adherence has been associated with a large variety of health benefits. However, prospective studies investigating the relation between MD adherence and colorectal cancer risk had inconsistent results. In this analysis of the Netherlands Cohort Study (NLCS), we evaluated sex- and subsite-specific associations of MD adherence with colorectal cancer risk. In 1986, 120,852 subjects filled out the NLCS baseline questionnaire, which incorporated a 150-item food frequency questionnaire. MD adherence was estimated through alternate Mediterranean diet scores including and excluding alcohol (aMED and aMEDr, respectively). Using 20.3 year follow-up data, 1993 male and 1574 female colorectal cancer cases could be included in multivariable case-cohort analyses. aMEDr was not significantly associated with colorectal cancer risk, regardless of sex. Hazard ratios (95% confidence intervals) per two-point increment were 1.04 (0.95–1.13) for men and 0.97 (0.88–1.07) for women. Additionally, there was no evidence of an inverse association with any of the colorectal cancer subsites (colon, proximal colon, distal colon, and rectum). In women, the association between aMEDr and colorectal cancer risk was significantly modified by smoking status (P_interaction = 0.015). Comparable results were obtained for the original aMED including alcohol. In conclusion, higher MD adherence was not associated with a reduced risk of colorectal cancer or anatomical subsites in the context of a Dutch population.