Proximal tumors are associated with greater mortality in colon cancer

An Activated Dendritic-Cell-Related Gene Signature Indicative of Disease Prognosis and Chemotherapy and Immunotherapy Response in Colon Cancer Patients

Accumulating evidence has underscored the prognostic value of tumor-infiltrating immune cells in the tumor microenvironment of colon cancer (CC). In this retrospective study, based on publicly available transcriptome profiles and clinical data from the Gene Expression Omnibus and The Cancer Genome Atlas databases, we derived and verified an activated dendritic cell (aDC)-related gene signature (aDCRS) for predicting the survival outcomes and chemotherapy and immunotherapy response of CC patients. We quantified the infiltration abundance of 22 immune cell subtypes via the "CIBERSORT" R script. Univariate Cox proportional hazards (PHs) regression was used to identify aDC as the most robust protective cell type for CC prognosis. After selecting differentially expressed genes (DEGs) significantly correlated with aDC infiltration, we performed univariate Cox-PH regression, LASSO regression, and stepwise multivariate Cox-PH regression successively to screen out prognosis-related genes from selected DEGs for constructing the aDCRS. Receiver operating characteristic (ROC) curves and Kaplan-Meier (KM) analysis were employed to assess the discriminatory ability and risk-stratification capacity. The "oncoPredict" package, Cancer Treatment Response gene signature DataBase, and Tumor Immune Dysfunction and Exclusion algorithm were utilized to estimate the practicability of the aDCRS in predicting response to chemotherapy and immune checkpoint blockade. Gene set enrichment analysis and single-cell RNA sequencing analysis were also implemented. Furthermore, an aDCRS-based nomogram was constructed and validated via ROC curves, calibration plots and decision curve analysis. In conclusion, aDCRS and an aDCRS-based nomogram will facilitate precise prognosis prediction and individualized therapeutic interventions, thus improving the survival outcomes of CC patients in the future.

Histopathology and levels of proteins in plasma associate with survival after colorectal cancer diagnosis

BACKGROUND

The TNM system is used to assess prognosis after colorectal cancer (CRC) diagnosis. Other prognostic factors reported include histopathological assessments of the tumour, tumour mutations and proteins in the blood. As some of these factors are strongly correlated, it is important to evaluate the independent effects they may have on survival.

METHODS

Tumour samples from 2162 CRC patients were visually assessed for amount of tumour stroma, severity of lymphocytic infiltrate at the tumour margins and the presence of lymphoid follicles. Somatic mutations in the tumour were assessed for 2134 individuals. Pre-surgical levels of 4963 plasma proteins were measured in 128 individuals. The associations between these features and prognosis were inspected by a Cox Proportional Hazards Model (CPH).

RESULTS

Levels of stroma, lymphocytic infiltration and presence of lymphoid follicles all associate with prognosis, along with high tumour mutation burden, high microsatellite instability and TP53 and BRAF mutations. The somatic mutations are correlated with the histopathology and none of the somatic mutations associate with survival in a multivariate analysis. Amount of stroma and lymphocytic infiltration associate with local invasion of tumours. Elevated levels of two plasma proteins, CA-125 and PPP1R1A, associate with a worse prognosis.

CONCLUSIONS

Tumour stroma and lymphocytic infiltration variables are strongly associated with prognosis of CRC and capture the prognostic effects of tumour mutation status. CA-125 and PPP1R1A may be useful prognostic biomarkers in CRC.

Overall Survival Differences in Young Black Colorectal Cancer Patients: a Report from the National Cancer Database

Objectives: Black patients have the highest overall incidence rate of early onset colorectal cancer, with many of these patients presenting with more aggressive disease at diagnosis, ultimately leading to decreased overall survival. We aimed to (1) evaluate how race and age affected overall survival in colorectal cancer patients, and (2) determine the different demographic and clinical covariables that may influence survival in younger individuals. Methods: The 2017 National Cancer Database (NCDB) was used to identify all patients that had colorectal cancer between 2004-2017. These patients were then divided into groups according to age (<45 and ≥45 years old) and race (white and black). Overall survival (OS) between white and black groups according to age was compared. Initial testing of survivor functions between groups revealed violations of the proportional hazards assumption. Accordingly, we used parametric maximum likelihood analyses fitting the survivor functions to Weibull distributions. Logistic regression analysis was used to determine univariate and multivariate relationships between the covariates and race for younger subjects. Propensity score matching analysis was also used to control for differences in the demographic or clinical variables between the young black versus white subgroups. Results: Out of 1.4 million potential cases initially identified, 207,823 unique cases were deemed eligible for evaluation based on study criteria. Black patients in the study population were more likely to be female, have medical comorbidities, and come from areas with lower average income and baseline education. OS was lower in older patients of both race categories when compared to the younger cohorts. Among patients older than 45 years, there were no significant differences in proportional hazard of death between black and white patients. However, among those younger than 45 years, younger black patients had significantly increased hazard of death. Regarding disease burden at diagnosis, pathologic characteristics and overall risk of death, there were no significant differences between black and white patients. Conclusions: Overall survival in young black patients with colorectal cancer is significantly reduced when compared to young white patients, even when controlling for demographic and pathologic factors. This suggests that the outcome disparities between black and white patients are complex, and the underlying factors are not well understood.

Mitochondrial remodeling in colorectal cancer initiation, progression, metastasis, and therapy: A review

Colorectal cancer (CRC) is a major health concern with multifactorial pathophysiology representing intense therapeutic challenges. It is well known that deregulation of spatiotemporally-controlled signaling pathways and their metabolic reprogramming effects play a pivotal role in the development and progression of CRC. As such, the mitochondrial role in CRC initiation gained a lot of attention recently, as it is considered the powerhouse that regulates the bioenergetics in CRC. In addition, the crosstalk between microRNAs (miRNAs) and mitochondrial dysfunction has become a newfangled passion for deciphering CRC molecular mechanisms. This review sheds light on the relationship between different signaling pathways involved in metabolic reprogramming and their therapeutic targets, alterations in mitochondrial DNA content, mitochondrial biogenesis, and mitophagy, and the role of polymorphisms in mitochondrial genes as well as miRNAs regulating mitochondrial proteins in CRC initiation, progression, metastasis, and resistance to various therapies.

A Belgian Population-Based Study Reveals Subgroups of Right-Sided Colorectal Cancer with a Better Prognosis Compared to Left-sided Cancer

BACKGROUND

Patients with left-sided colorectal cancer (L-CRC) are known to have a significantly better prognosis than those with right-sided CRC (R-CRC). It has been hypothesized that RAS, BRAF mutations, or deficient mismatch repair status (MMR) might be responsible for the prognostic effect of primary tumor location (PTL). This study aims to evaluate the prognostic effect of PTL in the Belgian population and to determine the role of biomarkers (MMR, BRAF, and RAS status) in this effect.

PATIENTS AND METHODS

We performed a retrospective analysis of Belgian Cancer Registry data. First, we studied the prognostic effect of PTL on 5-year relative survival of 91 946 patients diagnosed with CRC (all stages) from 2004-2015. Second, we investigated the interaction between biomarkers and the prognostic effect of PTL in 1818 patients diagnosed with stage IV CRC in 2014-2015.

RESULTS

L-CRC was associated with a significantly better 5-year relative survival compared to R-CRC in all stages and ages combined (68.4%, 95% CI, 67.7-69.1% vs 65.6%, 95% CI, 64.7-66.4%). Also, when stratified by age, sex, and stage, the prognosis of L-CRC was better compared to R-CRC in most subgroups. Only in stage II and certain subgroups of elderly patients, the opposite was observed. Furthermore, our data showed that none of the biomarkers had a significant interaction with the effect of PTL on survival.

CONCLUSION

This population-based study confirms that L-CRC is associated with significantly better relative survival compared to R-CRC, in all stages and ages combined. Furthermore, in stage IV L-CRC is associated with a longer survival than R-CRC, regardless of MMR, RAS, and BRAF status.

Transcriptomic and functional analyses reveal a tumour-promoting role for the IL-36 receptor in colon cancer and crosstalk between IL-36 signalling and the IL-17/ IL-23 axis

BACKGROUND

The interleukin (IL)-36 cytokines are a sub-family of the IL-1 family which are becoming increasingly implicated in the pathogenesis of inflammatory diseases and malignancies. Initial studies of IL-36 signalling in tumorigenesis identified an immune-mediated anti-tumorigenic function for these cytokines. However, more recent studies have shown IL-36 cytokines also contribute to the pathogenesis of lung and colorectal cancer (CRC).

METHODS

The aim of this study was to investigate IL-36 expression in CRC using transcriptomic datasets and software such as several R packages, Cytoscape, GEO2R and AnalyzeR. Validation of results was completed by qRT-PCR on both cell lines and a patient cohort. Cellular proliferation was assessed by flow cytometry and resazurin reduction.

RESULTS

We demonstrate that IL-36 gene expression increases with CRC development. Decreased tumoral IL-36 receptor expression was shown to be associated with improved patient outcome. Our differential gene expression analysis revealed a novel role for the IL-36/IL-17/IL-23 axis, with these findings validated using patient-derived samples and cell lines. IL-36γ, together with either IL-17a or IL-22, was able to synergistically induce different genes involved in the IL-17/IL-23 axis in CRC cells and additively induce colon cancer cell proliferation.

CONCLUSIONS

Collectively, this data support a pro-tumorigenic role for IL-36 signalling in colon cancer, with the IL-17/IL-23 axis influential in IL-36-mediated colon tumorigenesis.

Endoscopic polypectomy for malignant polyps: Should tumor location (right versus left side) guide clinical decisions?

BACKGROUND

Current guidelines consider endoscopic resection appropriate treatment for malignant colon polyps with negative margins, low-grade histology, and no lymphovascular invasion. While increasing literature demonstrates a worse prognosis for advanced stage right- versus left-sided colon cancers after curative treatment, there is paucity of data regarding prognostic effect of location in patients undergoing endoscopic resection of T1 polyps. We hypothesized the more aggressive biologic behavior observed in advanced right-sided cancers would be similarly represented in malignant polyps, and this location would be associated with lower overall survival.

METHODS

The National Cancer Database was queried for adults with T1NxMx tumors who underwent endoscopic polypectomy (2004-2017). Patients with positive margins or without follow-up information were excluded.

RESULTS

A total of 2,337 patients met inclusion criteria; 22% had right-sided polyps. Endoscopically excised proximal tumors were more common in elderly, and those with public insurance and more comorbidities (all P < .01). Among patients with complete pathologic data, there were no statistical differences between right- and left-sided polyps with 1 cm median size, >92% without lymphovascular invasion, and 100% without tumor deposits. Univariate analysis showed 73% vs 86% 5-year overall survival for right versus left polyps (P < .01). After adjustment for available confounders, right-sided location remained significantly associated with worse overall survival (hazard ratio 1.49, 95% confidence interval 1.21-1.83).

CONCLUSION

In this national cohort of patients with endoscopically excised malignant polyps, we identified right colon location as an independent prognostic factor associated with increased risk of mortality. Our data suggest polyp location should be taken into consideration when making clinical decisions regarding treatment and/or surveillance.

The interaction between glycemic index, glycemic load, and the genetic variant ADIPOQ T45G (rs2241766) in the risk of colorectal cancer: a case-control study in a Korean population

PURPOSE

The glycemic index (GI), glycemic load (GL), and adiponectin level contribute to glycemic response and insulin sensitivity in the body. Studies have shown that tumor development is related to glycemic disorders; however, the results are contradictory. We aimed to investigate the association of GI and GL with colorectal cancer (CRC) risk in a Korean population and their possible interactions with the genetic variant ADIPOQ T45G.

METHODS AND RESULTS

A case-control study including 2096 participants with 695 CRC cases was conducted. The results showed that diets with high GI or GL were significantly associated with an increased risk of CRC [odds ratio (OR) = 5.44, 95% confidence interval (CI) 3.85-7.68; OR = 4.43, 95% CI 3.18-6.15, respectively; all p-trends < 0.001]. Moreover, even with a low-GI and low-GL diet, G/G genotype carriers may have 2.93-fold and 3.77-fold higher risk of rectal cancer compared to carriers of other genotypes (T/T + T/G), (OR = 2.93, 95% CI 1.01-8.59, p-interaction = 0.011 for GI; OR = 3.77, 95% CI 1.46-9.77, p-interaction = 0.025 for GL).

CONCLUSIONS

Overall, our study suggests positive associations of GI and GL with CRC risk. Moreover, the associations of GI and GL with rectal cancer risk could be modified by ADIPOQ T45G in a Korean population. Further studies with larger sample sizes are needed to confirm our findings.

Propensity Score Matching Analysis of the Effect of Payer Status on the Survival of Colon Cancer Patients

Background and objective

Colon cancer is one of the most common types of cancer globally. The factors that could affect colon cancer survival include age, stage, treatment, and other socioeconomic aspects. Payer status has been shown to be a significant predictor of cancer patient survival in retrospective studies. However, due to the limitations of retrospective studies, patient baseline characteristics between payer statuses are not comparable. Few studies have addressed the effect of payer status on the overall survival (OS) of patients using propensity score matching (PSM). In light of this, we conducted a study to examine the effect of payer status on the survival of colon cancer patients based on PSM.

Materials and methods 

About 66,493 stage II/III colon cancer patients aged 40-90 years and diagnosed between 2004 and 2015 were analyzed from a de-identified National Cancer Database (NCDB) file. All patients had undergone surgery, and patients who had received radiation therapy, hormone therapy, immunotherapy, palliative care, or therapies other than chemotherapy were excluded. Only private or Medicaid payer status was included. The propensity score was calculated by computing the probability of patients being in the Medicaid group using logistic regression. The PSMATCH procedure in the SAS software (SAS Inc., Gary, NC) was used to perform PSM on patients with Medicaid and private insurance. The greedy nearest neighbor matching method was used to match one Medicaid to one privately insured patient with a caliper of 0.2. At the same time, an exact match was done for gender, age group, race, and stage at diagnosis. Multivariate Cox regression was then used to estimate the effect of payer status on survival before and after PSM.

Results

Among the 66,493 patients, 90.3% were privately insured and 9.7% had Medicaid. In univariate analysis, payer status was found to be a significant predictor of OS. Prior to PSM, the median overall survival (MOS) for patients with private insurance was 12.75 years, while those with Medicaid had a MOS of 9.02 years. After PSM, 6,167 paired patients were matched, and patients with private insurance had a MOS of >12.82 years and Medicaid patients had a MOS of 8.88 years. After PSM, patients with Medicaid had a 50% increased risk of death, and payer status proved to be a statistically significant predictor of OS of colon cancer.

Conclusion

Based on our findings, as per the PSM method, payer status can be a significant predictor of survival among colon cancer patients. Also, chemotherapy, race, age, and other socioeconomic factors were also found to be significant predictors of OS. Further research should be conducted to investigate other covariates not studied here and the mediation effect of payer on the survival of cancer patients.

Colorectal Cancer Trends of 2018 in Romania-an Important Geographical Variation Between Northern and Southern Lands and High Mortality Versus European Averages

PURPOSE

In Romania, one of the highest rates for colorectal cancer (CRC) incidence and mortality in Europe was estimated based on data available in 2008. Ever since, consistent data are missing. In this article, we tried to estimate the general burden of CRC in our country.

METHODS

We collected data from all hospitalized recorded cases according to the ICD-10 revision (codes C18-C20), as both primary and secondary diagnoses, as reported by all the hospitals to the DRG National System, between 2016 and 2018.

RESULTS

There were 50,890 persons hospitalized with CRC. The prevalence of hospitalized colorectal cancer was 108.24/100,000 inhabitants in 2016, 113.09/100,000 inhabitants in 2017, and 116.83/100,000 inhabitants in 2018. Distal localization prevailed. We registered 34.13/100,000 deaths by CRC within the mentioned period of time, almost twofold higher than average European range. There are significant geographical differences regarding CRC prevalence and mortality, with higher rates in the Northern and Central Regions, and a very low prevalence and mortality in Bucharest and Southern provinces.

CONCLUSION

We note a high colorectal mortality rate in Romania, especially in the Northern and Central Regions, nearly double versus European ranges.

The rise of proximal colorectal cancer: a trend analysis of subsite specific primary colorectal cancer in the SEER database

Background

Colorectal cancer (CRC) is the third most common cancer worldwide and the second leading cause of cancer-related deaths. Given the significant prevalence of CRC, regular preventative screening is required. CRCs in different locations of the colon have variable molecular pathogenesis, gross appearance, and general disease outcomes. While the overall incidence of CRC has been decreasing, the decrease in proximally located CRC significantly lags behind the other forms of CRC. The objective of this study was to establish independent risk factors for proximal CRC for better identification of populations at risk for closer CRC monitoring and observation.

Methods

A time-trend analysis was conducted using data from the National Cancer Institute’s Surveillance, Epidemiology, and End Results (SEER) database from 1973-2007, comparing patient characteristics (age, sex, race/ethnicity, year of diagnosis, age of diagnosis, tumor grade, tumor stage, and urban-rural setting) between CRCs originating in different locations.

Results

Analysis demonstrated that black race, female sex, age over 60, and being diagnosed in the 21st century (rather than 20th) were associated with an increased risk of proximal CRC compared to CRCs originating in other locations.

Conclusions

Our study showed that black race, female sex, and age over 60 independently increased the likelihood of proximal CRC diagnosis. Furthermore, CRC trends identify an increasing proportion of all CRCs being of proximal origin. It is imperative that patients undergo regularly scheduled complete colonoscopies by trained endoscopists, especially if they belong to the high-risk groups previously identified.

Interleukins 4 and 13 and Their Receptors Are Differently Expressed in Gastrointestinal Tract Cancers, Depending on the Anatomical Site and Disease Advancement, and Improve Colon Cancer Cell Viability and Motility

Immunosuppressive interleukins (IL)-4 and 13 may directly promote cancer but neither their status nor role in gastrointestinal tract is clarified. We aim at quantifying ILs and their receptors in paired normal-tumor samples (n = 49/51) and sera (n = 263), using immunoassays and RTqPCR, and screening for their effect on colonic cancer cells. Both ILs were elevated locally at protein level in all cancers but only IL13 transcripts in colon were upregulated. Interleukin and their receptor expression reflected cancer pathology to varying degrees, with the association frequently inverse and manifested in non-cancerous tissue. Positive correlation with cancer-promoting genes BCL2, BCLxL, HIF1A, VEGFA, ACTA2, CCL2, PTGS2, and CDKN1A, but not Ki67, was demonstrated, particularly for ILs' receptors. Circulating IL-4 was elevated in all, while IL-13 only in colorectal or esophageal cancers, reflecting their advancement. IL4Ra and IL13Ra1 transcripts were downregulated by hypoxia and, in Caco-2, also by IL-4. Interleukin stimulation slightly improved colonic cancer cell viability, weakly upregulating BCL2 and Ki67 in HCT116 and HT-29. It affected cell motility more markedly and was consistently accompanied by upregulation of claudin-2. Gastrointestinal tract cancers are associated with IL-4 and IL-13 upregulation, which may facilitate cancer growth. Targeting both interleukins as an antineoplastic strategy warrants further investigation.

Clinical and prognostic differences between surgically resected right-sided and left-sided colorectal cancer

PURPOSE

A growing body of evidence suggests that right-sided colorectal cancer (RCRC) differs from left-sided colorectal cancer (LCRC) in certain clinicopathological features. Therefore, we investigated the difference between RCRC and LCRC in a series of 899 patients.

METHODS

We reviewed data retrospectively, from 899 patients who underwent R0-resection for stage II and III CRC and compared the clinicopathological factors between patients with RCRC and LCRC.

RESULTS

The patients with RCRC tended to be older, more likely female, with a larger tumor, higher pathological T stage, and a greater proportion of their tumors were poorly differentiated adenocarcinoma, mucinous adenocarcinoma, or signet ring cell carcinoma than the patients with LCRC,. Recurrence-free survival (RFS) of the patients with RCRC tended to be higher than that of the patients with LCRC and was significantly better among patients with stage II cancer. The overall survival (OS) was similar for patients with RCRC and LCRC, irrespective of cancer stage.

CONCLUSION

Compared with the patients with LCRC, those with RCRC had several oncologically unfavorable factors, with better RFS in stage II and similar OS in stages II and III. These results suggest that the biological aggressiveness of RCRC is lower than that of LCRC in stage II; however, it can increase after relapse.

Heterogeneity of Colorectal Cancer Risk Factors by Anatomical Subsite in 10 European Countries: A Multinational Cohort Study

BACKGROUND & AIMS

Colorectal cancer located at different anatomical subsites may have distinct etiologies and risk factors. Previous studies that have examined this hypothesis have yielded inconsistent results, possibly because most studies have been of insufficient size to identify heterogeneous associations with precision.

METHODS

In the European Prospective Investigation into Cancer and Nutrition study, we used multivariable joint Cox proportional hazards models, which accounted for tumors at different anatomical sites (proximal colon, distal colon, and rectum) as competing risks, to examine the relationships between 14 established/suspected lifestyle, anthropometric, and reproductive/menstrual risk factors with colorectal cancer risk. Heterogeneity across sites was tested using Wald tests.

RESULTS

After a median of 14.9 years of follow-up of 521,330 men and women, 6291 colorectal cancer cases occurred. Physical activity was related inversely to proximal colon and distal colon cancer, but not to rectal cancer (P heterogeneity = .03). Height was associated positively with proximal and distal colon cancer only, but not rectal cancer (P heterogeneity = .0001). For men, but not women, heterogeneous relationships were observed for body mass index (P heterogeneity = .008) and waist circumference (P heterogeneity = .03), with weaker positive associations found for rectal cancer, compared with proximal and distal colon cancer. Current smoking was associated with a greater risk of rectal and proximal colon cancer, but not distal colon cancer (P heterogeneity = .05). No heterogeneity by anatomical site was found for alcohol consumption, diabetes, nonsteroidal anti-inflammatory drug use, and reproductive/menstrual factors.

CONCLUSIONS

The relationships between physical activity, anthropometry, and smoking with colorectal cancer risk differed by subsite, supporting the hypothesis that tumors in different anatomical regions may have distinct etiologies.

Association of genetic ancestry with colorectal tumor location in Puerto Rican Latinos

Background

Colorectal cancer (CRC) is the first cause of cancer deaths among Puerto Ricans. The incidence and mortality of CRC in Puerto Rico continue to be on the rise. The burden of CRC in Puerto Rico is higher than among US Hispanics and is second only to African Americans, thus supporting the importance of studying this CRC health disparity. The genetic background of the Puerto Rican population is a mix of European, African, and Amerindian races, which may account, in part, for the differences observed in the CRC mortality rates among Puerto Ricans. The objective of the study was to assess the role of genetic ancestry in CRC risk and its association with clinicopathological features of CRC tumors in Puerto Ricans.

Results

We used a validated panel of 105 ancestry informative markers (AIMs) to estimate genetic ancestry in 406 Puerto Rican CRC cases and 425 Puerto Rican controls. We examined the association of genetic ancestry with CRC risk and tumor clinicopathological characteristics.

Conclusions

The mean ancestry proportions in the study population were 61% European, 21% African, and 18% Amerindian. No association was observed between genetic ancestry and risk of CRC. However, African ancestry was associated with an increased risk of developing rectal tumors (OR = 1.55, 95% CI 1.04–2.31). Additional studies are needed to fully elucidate the role of African ancestry in CRC carcinogenesis.

Assessment of intra-tumoural colorectal cancer prognostic biomarkers using RNA in situ hybridisation

Genome-wide expression studies using microarrays and RNAseq have increased our understanding of colorectal cancer development. Translating potential gene biomarkers from these studies for clinical utility has typically relied on PCR-based technology and immunohistochemistry. Results from these techniques are limited by tumour sample heterogeneity and the lack of correlation between mRNA transcript abundance and corresponding protein levels. The aim of this research was to investigate the clinical utility of the RNA in situ hybridisation technique, RNAscope^®, for measuring intra-tumoural gene expression of potential prognostic markers in a colorectal cancer cohort. Two candidate gene markers (GFI1 and TNFRSF11A) assessed in this study were identified from a previous study led by the The Cancer Genome Atlas (TCGA) Network, and analysis was performed on 112 consecutively collected, archival FFPE colorectal cancer tumour samples. Consistent with the TCGA Network study, we found reduced GFI1 expression was associated with high-grade and left-sided tumours, and reduced TNFRSF11A expression was associated with metastasis and high nodal involvement. RNAscope^® combined with image analysis also enabled quantification of GFI1 and TNFRSF11A mRNA expression levels at the single cell level, allowing cell-type determination. These data showed that reduced mRNA transcript abundance measured in patients with poorer prognosis occurred in carcinoma cells, and not lymphocytes, stromal cells or normal epithelial cells. To our knowledge, this is the first study to assess the intra-tumoural expression patterns of GFI1 and TNFRSF11A and to validate their microarray expression profiles using RNAscope. We also demonstrate the utility of RNAscope^® technology to show that expression differences are derived from carcinoma cells rather than from cells located in the tumour microenvironment.

Subsite heterogeneity in the profiles of circulating cytokines in colorectal cancer

Colorectal cancers (CRCs) are treated as one entity but are in fact a heterogeneous group of diseases. If not addressed, subsite-associated variability may interfere with mechanism-targeted therapies and accuracy of potential CRC biomarkers. Little is known about the contribution of systemic inflammatory and immune mediators to subsite heterogeneity in CRC. Our purpose was to compare the profiles of key cytokines between right and left colonic and rectal CRCs. Using Luminex xMAP® technology, serum concentrations of eotaxin, IL-1β, IL-1ra, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, IL-9, IL-10, IL-12(p70), IL-13, IL-15, IL-17, IFNγ, IP-10, FGF-2, G-CSF, GM-CSF, MCP-1, MIP-1α and β, PDGF-BB, RANTES, TNFα, and VEGF-A were determined in 104 CRC patients. We found the concentrations of IL-12(p70), IL-10, IL-1ra, IL-4, IL-6, IL-7, IL-8, G-CSF and TNFα to be significantly higher in right-sided and GM-CSF in left-sided than rectal CRCs. The concentrations of IFNγ and MIP-1α were significantly higher in right-sided CRCs as compared to cancers of other locations combined. In turn, MIP-1β was higher in rectal CRCs as compared to colon cancers. Taken together, our results show subsite heterogeneity of CRC cancers in terms of systemic inflammatory and immune responses that ought to be taken into account when attempting immunotherapy or developing biomarkers. Additionally, more pronounced T_H2 response accompanied by T_H1 immunity and more prominent tumor-promoting inflammation in CRC patients with primary tumors originating from right-sided colon may constitute a molecular background of unfavorable prognosis associated with this location.

Composition and Concentration of Serum Fatty Acids of Phospholipids Depend on Tumour Location and Disease Progression in Colorectal Patients

BACKGROUND

Polyunsaturated fatty acids (PUFAs) play a role in the development/progression of colon cancer. The aim of the study was to assess the relation between serum phospholipids PUFAs, colorectal tumour localization and disease progression.

METHODS

A total of 67 patients (18 with proximal colon, 17 with distal colon and 32 with rectal tumour localization) as well as 16 controls were studied. One year after surgery, 33 patients had disease progression. Serum levels of C16:1(n-7), C18:1(n-9), C18:3(n-3), C20:5(n-3), C22:6(n- 3), C18:2(n-6), C20:2(n-6), C20:4(n-6) fatty acids of se - rum phospholipids were quantitatively measured before surgery by gas-chromatography.

RESULTS

Significantly higher mean value of C18:2, as compared to control, has been noted only for patients with proximal (p<0.05) and distal tumour (p<0.03) localization. The lower mean level of C20:5 and unsaturation index (UI) were observed in colorectal cancer patients regardless the tumour localization, but the statistical difference was noted only for patients with proximal tumours (p<0.05, p<0.03). In patients with proximal tumours, significantly lower mean level of C20:4 and UI were noted in patients with disease progression, as compared to patients with proximal tumours without disease progression (p<0.05).

CONCLUSION

The evaluation of PUFAs as a risk/prognostic factor in colorectal cancer patients should take into account tumour localization as a dependent variable.

Colorectal Cancer Incidence Trend and Projections in Tunisia (1994 - 2024)

Objectives: The aim of this study was to describe trends of colorectal cancer incidence during the period 1994-2009 and to generate projections until 2024. Methods: The North-Tunisia Cancer Registry (NTCR) was the source of data for patients with CRC. This registry lists, since 1994, cases of malignant tumors in people living in North Tunisia, including the District of Tunis, the north east and the north west. Cases were classified using the International Classification of Diseases for Oncology. Data were analyzed using R software and Joinpoint one was employed to analyse trends. Projections were performed using the Age Period Cohort based on poisson regression. Results: During the period 1994 to 2009, 6,909 new cases of CRC were registered in Northern Tunisia. The age standardized incidence rate (ASR) increased significantly from 6.4/100,000 in 1994 to 12.4/100,000 in 2009. Trends in CRC incidence was significantly rising with an annual percentage change (APC) of + 3,9% [2.8% -5.1%]. Without effective interventions, the predicted CRC ASR would be 39.3/100,000 [CI 95%: 32,9/100,000 - 48,8/100,000] in 2024. Conclusion: The incidence of colorectal cancer is clearly increasing in Tunisia. Strengthening of screening and primary prevention measures is to be recommended.

Colorectal Cancer in African Americans: An Update

This review is an update to the American College of Gastroenterology (ACG) Committee on Minority Affairs and Cultural Diversity's paper on colorectal cancer (CRC) in African Americans published in 2005. Over the past 10 years, the incidence and mortality rates of CRC in the United States has steadily declined. However, reductions have been strikingly much slower among African Americans who continue to have the highest rate of mortality and lowest survival when compared with all other racial groups. The reasons for the health disparities are multifactorial and encompass physician and patient barriers. Patient factors that contribute to disparities include poor knowledge of benefits of CRC screening, limited access to health care, insurance status along with fear and anxiety. Physician factors include lack of knowledge of screening guidelines along with disparate recommendations for screening. Earlier screening has been recommended as an effective strategy to decrease observed disparities; currently the ACG and American Society of Gastrointestinal Endoscopists recommend CRC screening in African Americans to begin at age 45. Despite the decline in CRC deaths in all racial and ethnic groups, there still exists a significant burden of CRC in African Americans, thus other strategies including educational outreach for health care providers and patients and the utilization of patient navigation systems emphasizing the importance of screening are necessary. These strategies have been piloted in both local communities and Statewide resulting in notable significant decreases in observed disparities.

A randomized trial to compare the efficacy and tolerability of sodium picosulfate-magnesium citrate solution vs. 4 L polyethylene glycol solution as a bowel preparation for colonoscopy

PURPOSE

The purpose of this study is to compare the efficacy and acceptability of an evening-before regimens of sodium picosulfate/magnesium citrate (SPMC) and polyethylene glycol (PEG) as bowel cleansers and to explore the results of a same-day regimen of SPMC.

METHODS

Multicenter, randomized, observer-blinded, parallel study carried out in subjects who were 18-80 years old and were undergoing diagnostic colonoscopy for the first time. The primary outcome was treatment success, which was a composite outcome defined by (1) the evaluation of the overall preparation quality as "excellent" or "good" by two blinded independent evaluators with the Fleet(®) Grading Scale for Bowel Cleansing and (2) a subject's acceptability rating of "easy to take" or "tolerable." The primary outcome was analyzed using a logistic regression with site, gender, and age group (age ≥65 years and <65 years) as factors.

RESULTS

Four hundred ninety subjects were included in the efficacy evaluation. Although treatment success was significantly higher in subjects assigned to the evening-before regimen of SPMC vs. subjects assigned to the evening-before PEG, when evaluating the two individual components for treatment success, there were significant differences in the ease of completion but not in the quality of preparation. The same-day SPMC regimen was superior to both the evening-before regimen of SPMC and PEG in terms of the quality of preparation, especially regarding the proximal colon.

CONCLUSIONS

An evening-before regimen of SPMC is superior to an evening-before regimen of PEG in terms of subject's acceptability. The same-day SPMC regimen provides better cleansing levels in the proximal colon.

Characterization of the Hispanic or latino population in health research: a systematic review

The size and diversity of the Hispanic population in the United States has dramatically increased, with vast implications for health research. We conducted a systematic review of the characterization of the Hispanic population in health research and described its implications. Relevant studies were identified by searches of PubMed, Embase Scopus, and Science/Social Sciences Citation Index from 2000 to 2011. 131 articles met criteria. 56% of the articles reported only "Hispanic" or "Latino" as the characteristic of the Hispanic research population while no other characteristics were reported. 29% of the articles reported language, 27% detailed country of origin and 2% provided the breakdown of race. There is great inconsistency in reported characteristics of Hispanics in health research. The lack of detailed characterization of this population ultimately creates roadblocks in translating evidence into practice when providing care to the large and increasingly diverse Hispanic population in the US.

Different clinicopathologic features and favorable outcomes of patients with stage III left-sided colon cancer

Background

We evaluated the clinicopathologic features and outcomes of Taiwanese patients with right-sided versus left-sided colon cancer according to various cancer stages.

Methods

A total of 1095 patients with primary colorectal cancer (CRC) undergoing surgery at a single-institution were enrolled. We analyzed patient differences in terms of clinicopathologic features, overall survival (OS) and cancer-specific survival (CSS) of right- versus left-sided colon cancer.

Results

Right-sided colon cancers were noted in 249 (22.7 %) patients, and left-sided colon cancers were noted in 846 (77.3 %) patients. Right-sided colon cancers were found to be significantly larger (P = 0.003) and poorly differentiated (P < 0.001), while also exhibiting advanced depth of tumor invasion (P = 0.002) and advanced UICC/AJCC stage (P = 0.016). Patients with right-sided colon cancers had both poorer OS and CSS than those with left-sided colon cancers (P = 0.021 and 0.023, respectively). However, analysis by various stages revealed significant OS and CSS differences (P = 0.002 and 0.002, respectively) between right-sided and left-sided colon cancers only in stage III patients.

Conclusions

This study demonstrated poorer OS and CSS in patients with right-sided versus those with left-sided colon cancers, but significant differences were noted only in stage III patients.

Wild-type APC predicts poor prognosis in microsatellite-stable proximal colon cancer

Background:

APC mutations (APC-mt) occur in ∼70% of colorectal cancers (CRCs), but their relationship to prognosis is unclear.

Methods:

APC prognostic value was evaluated in 746 stage I–IV CRC patients, stratifying for tumour location and microsatellite instability (MSI). Microarrays were used to identify a gene signature that could classify APC mutation status, and classifier ability to predict prognosis was examined in an independent cohort.

Results:

Wild-type APC microsatellite stable (APC-wt/MSS) tumours from the proximal colon showed poorer overall and recurrence-free survival (OS, RFS) than APC-mt/MSS proximal, APC-wt/MSS distal and APC-mt/MSS distal tumours (OS HR⩾1.79, P⩽0.015; RFS HR⩾1.88, P⩽0.026). APC was a stronger prognostic indicator than BRAF, KRAS, PIK3CA, TP53, CpG island methylator phenotype or chromosomal instability status (P⩽0.036). Microarray analysis similarly revealed poorer survival in MSS proximal cancers with an APC-wt-like signature (P=0.019). APC status did not affect outcomes in MSI tumours. In a validation on 206 patients with proximal colon cancer, APC-wt-like signature MSS cases showed poorer survival than APC-mt-like signature MSS or MSI cases (OS HR⩾2.50, P⩽0.010; RFS HR⩾2.14, P⩽0.025). Poor prognosis APC-wt/MSS proximal tumours exhibited features of the sessile serrated neoplasia pathway (P⩽0.016).

Conclusions:

APC-wt status is a marker of poor prognosis in MSS proximal colon cancer.

The loss in expectation of life after colon cancer: a population-based study

Background

To demonstrate how assessment of life expectancy and loss in expectation of life can be used to address a wide range of research questions of public health interest pertaining to the prognosis of cancer patients.

Methods

We identified 135,092 cases of colon adenocarcinoma diagnosed during 1961–2011 from the population-based Swedish Cancer Register. Flexible parametric survival models for relative survival were used to estimate the life expectancy and the loss in expectation of life.

Results

The loss in expectation of life for males aged 55 at diagnosis was 13.5 years (95 % CI 13.2–13.8) in 1965 and 12.8 (12.4–13.3) in 2005. For males aged 85 the corresponding figures were 3.21 (3.15–3.28) and 2.10 (2.04–2.17). The pattern was similar for females, but slightly greater loss in expectation of life. The loss in expectation of life is reduced given survival up to a certain time point post diagnosis. Among patients diagnosed in 2011, 945 life years could potentially be saved if the colon cancer survival among males could be brought to the same level as for females.

Conclusion

Assessment of loss in expectation of life facilitates the understanding of the impact of cancer, both on individual and population level. Clear improvements in survival among colon cancer patients have led to a gain in life expectancy, partly due to a general increase in survival from all causes.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-015-1427-2) contains supplementary material, which is available to authorized users.

Screening for colorectal cancer in African Americans: determinants and rationale for an earlier age to commence screening

Colorectal cancer (CRC) screening is a cost-effective approach to reduce morbidity, mortality, and prevalence of CRC in populations. Current recommendations for asymptomatic populations begin screening at age 50 years, after which ~95% of cancers occur. Determinants that modify timing and frequency for screening include: personal/family history of adenomas or CRC, age of onset of lesions, and presence or potential to harbor high-risk conditions like inflammatory bowel disease (IBD), familial adenomatous polyposis (FAP), or Lynch syndrome. Although race, like family history, is heritable, it has not engendered inclusion in systematic screening recommendations despite multiple studies demonstrating disparity in the incidence and mortality from CRC, and the potential for targeted screening to reduce disparity. African Americans, when compared to Caucasians, have lower CRC screening utilization, younger presentation for CRC, higher CRC prevalence at all ages, and higher proportion of CRCs before age 50 years (~11 vs. 5%); are less likely to transmit personal/family history of adenomas or CRC that may change screening age; show excess of high-risk proximal adenomas, matched with 7-15% excess right-sided CRCs that lack microsatellite instability; show higher frequencies of high-risk adenomas for every age decile; and demonstrate genetic biomarkers associated with metastasis. These epidemiological and biological parameters put African Americans at higher risk from CRC irrespective of socioeconomic issues, like IBD, FAP, and Lynch patients. Including race as a factor in national CRC screening guidelines and commencing screening at an age earlier than 50 years seems rational based on the natural history and aggressive behavior in this population.

Rectal Site and Suboptimal Nodal Yield Predict Systemic Recurrence in Resected Colorectal Carcinoma

We assessed the contribution of histopathological features to systemic recurrence (SR) in patients with colorectal cancer, using a case-control design: 71 cases and 184 controls were included, with a mean time until SR of 1.4 ± 0.1 years and a mean follow-up of controls of 1.6 ± 0.06 years. Cases had significantly greater odds of rectal site (odds ratio [OR] = 1.82), stage ≥pT3 (OR = 2.11), suboptimal (<12) lymph node yield (OR = 4.6), stage ≥pN1 (OR = 2.46), KRAS mutation (OR = 2.76), and extramural venous invasion (OR = 1.97). By multiple regression analysis, rectal site, stage ≥pT3, suboptimal lymph node yield, and lymph node positivity independently predicted SR. Rectal cancers were more likely to have a suboptimal node yield than nonrectal cancers (relative risk = 1.6) among the entire cohort. We conclude that rectal cancers have greater risk of SR than colon cancers. A lower yield of lymph nodes in rectal cancer specimens may contribute to this.

Colorectal cancer in patients seen at the teaching hospitals of Guadeloupe and Martinique: discrepancies, similarities in clinicopathological features, and p53 status

BACKGROUND

In Guadeloupe and Martinique, two French Overseas Departments, colorectal cancer (CRC) has become an essential public health issue. However, little is known about CRC characteristics and the p53 status in these populations, particularly in Guadeloupe, whereas certification of a cancer registry has been recently validated.

METHODS

This was a descriptive retrospective study of 201 patients who, between 1995 and 2000, underwent surgery for CRC in the Guadeloupe Teaching Hospital (GlpeTH; 83 patients) and in the Martinique Teaching Hospital (MqueTH; 118 patients). The clinicopathological features and the p53 expression, evaluated with immunohistochemistry, were compared at the time of diagnosis. A relationship between these parameters and the p53 expression was also studied. Data were analysed, using the SPSS computer software version 17.0.

RESULTS

No statistical difference was found between the two groups of patients regarding age (p = 0.60), percentage of young patients (≤50 years; p = 0.94)), sex (p = 0.47), histological type (p = 0.073) and tumour sites (p = 0.65), although the GlpeTH patients were diagnosed with more distal colon cancers (54.2%) than the Mque TH patients (47.4%). By contrast, a significant difference was found regarding the tumour grade (p < 0.0001), the pTNM stage (p = 0.045) and the pT stage (p < 0.0001). Regarding p53 expression, solely for the MqueTH patients, nuclear expression was associated with pTNM, the percentage of p53 negative tumours increasing with the progression of the pTNM stages (p = 0.029).

CONCLUSIONS

For the first time, this study reveals discrepancies in clinicopathological features and in the p53 status between the two groups of patients. The GlpeTH patients were diagnosed with more moderated CRCs but with few CRCs at pTNM IV stage. By contrast, the MqueTH patients were diagnosed with more differentiated tumours, but with many more CRCs at pTNM IV stage. This paradox may be due to differences in tumour location (distal vs proximal), multiplicity of the genetic profiles of patients, or patients getting treatment elsewhere. Although our study is limited due to its small size, it emphasizes the originality of our results.

Difference in the recurrence rate between right- and left-sided colon cancer: a 17-year experience at a single institution

Purpose

The prognostic differences between right- and left-sided colon cancer are controversial. This study aimed to clarify the clinical difference between right- and left-sided colon cancer.

Methods

We enrolled 820 patients with stage I/II/III colon cancer who underwent radical surgery with curative intent. We explored the impact of the tumor location on the postoperative disease-free survival (DFS) rate using the univariate and multivariate analyses.

Results

Right-sided disease occurred in 399 of the 820 patients. The mean follow-up period was 55.8 ± 34.9 months. The pathological stage distribution was as follows: stage I 261 patients; stage II 283; and stage III 251. There were no significant differences in the five-year DFS of the overall populations (right 88.6 %; left 89.4 %; P = 0.231). The subgroup analyses demonstrated that patients with stage I right-sided colon cancer had a significantly better 5-year DFS rate than did those with left-sided disease (100 vs. 95.2 %, P = 0.034). There were no significant differences in the distributions of the first recurrent sites (P = 0.559).

Conclusions

The tumor location may contribute to postoperative tumor recurrence. However, these effects were inconsistent across tumor stages. Our results provide a better understanding of the prognostic disparity between tumor locations; this may improve patient consent and postoperative surveillance.

Oncogenic mutations and microsatellite instability phenotype predict specific anatomical subsite in colorectal cancer patients

In colorectal cancer (CRC) oncogenic mutations such as KRAS alterations, are considered standard molecular biomarkers that predict the clinical benefit for targeted intervention with epidermal growth factor receptor (EGFR) inhibitors. In addition, these mutations are associated with specific anatomical area in colon tumor development, as BRAF mutations with the microsatellite instability (MSI). In this translational study, we aimed to assess the mutation frequencies of the EGFR (hotspot area and polyadenine deletions A13_del), KRAS, BRAF(V600E), and PIK3CA oncogenes in a series of 280 CRC patients. MSI phenotypes are also considered in this series. All patients' clinicopathological data were assessed for statistical analysis and its associations were validated. We verified multiple associations between oncogenic mutations and determined clinicopathological tumor features (1) EGFR A13_deletions are associated with right colon carcinoma (P<0.005), mucinous histotype (P=0.042), G3 grading (P=0.024), and MSI status (P<0.005); (2) PIK3CA mutations are related mucinous histotype (P=0.021); (3) KRAS(G12) and KRAS(G13) mutations are correlated, respectively, with the left and right colon cancer development (P<0.005), and finally (4) MSI is associated with right colon tumors (P<0.005). Mostly, we verified a higher frequency rate of the KRAS(G13) and EGFR A13_del oncogene mutations in right colon cancer; whereas KRAS(G12) codon mutation occurs more frequently in left colon cancers. In particular, we assessed that right vs left colon cancer are associated with specific molecular characteristics. These evidences, in association with clinicopathological data, can delineate novel approaches for the CRC classification and targeted intervention.

Clinicopathological differences of colorectal cancers according to tumor origin: Identification of possibly de novo lesions

Colorectal cancer (CRC) is considered to develop through the conventional adenoma-carcinoma sequence. However, the existence of de novo carcinogenesis, without any intervening precursor lesions, has been suggested for certain morphologically different tumors lacking polypoid characteristics. The presence of such tumors, along with their correlation with cardinal clinicopathological parameters, such as stage, grade and site, was retrospectively investigated in a series of 119 surgically treated CRC cases. The absence of particular polypoid characteristics (adenomatous remnants or coexisting polyps in the tumor vicinity) in combination with an infiltrative (or ulceroinfiltrative) growth pattern, were the criteria defining the nonpolypoid origin. The recorded frequencies of remnants, coexisting polyps and infiltrative tumors were 7, 5, 9 and 32%, respectively. The incidence of cases meeting the above-mentioned criteria was 28.5%. These nonpolypoid lesions exhibited a predilection for proximal anatomical site (P=0.04), probably associated with their infiltrative pattern. Most importantly, de novo lesions (unlike polypoid) were rarely found among cases with indolent tumor characteristics (stage I or grade I, P=0.008), showing a considerably different overall pattern of distribution by stage and grade as compared to that of polypoid tumors (P=0.03). The fact that nonpolypoid CRCs appeared to be clinicopathologically different from their polypoid counterparts is supportive of possible de novo origin and suggestive of a likely worse clinical behavior. The impact of these findings should be investigated to determine potential applications in the diagnosis, treatment and surveillance of these lesions.

Cancer statistics for Hispanics/Latinos, 2012

Hispanics/Latinos are the largest and fastest growing major demographic group in the United States, accounting for 16.3% (50.5 million/310 million) of the US population in 2010. In this article, the American Cancer Society updates a previous report on cancer statistics for Hispanics using incidence data from the National Cancer Institute, the Centers for Disease Control and Prevention, and the North American Association of Central Cancer Registries and mortality data from the National Center for Health Statistics. In 2012, an estimated 112,800 new cases of cancer will be diagnosed and 33,200 cancer deaths will occur among Hispanics. In 2009, the most recent year for which actual data are available, cancer surpassed heart disease as the leading cause of death among Hispanics. Among US Hispanics during the past 10 years of available data (2000-2009), cancer incidence rates declined by 1.7% per year among men and 0.3% per year among women, while cancer death rates declined by 2.3% per year in men and 1.4% per year in women. Hispanics have lower incidence and death rates than non-Hispanic whites for all cancers combined and for the 4 most common cancers (breast, prostate, lung and bronchus, and colorectum). However, Hispanics have higher incidence and mortality rates for cancers of the stomach, liver, uterine cervix, and gallbladder, reflecting greater exposure to cancer-causing infectious agents, lower rates of screening for cervical cancer, differences in lifestyle and dietary patterns, and possibly genetic factors. Strategies for reducing cancer risk among Hispanics include increasing utilization of screening and available vaccines, as well as implementing effective interventions to reduce obesity, alcohol consumption, and tobacco use.

Association of dietary quercetin with reduced risk of proximal colon cancer

Quercetin is a flavonol that appears to be protective against several cancers, but its possible role in prevention of colorectal cancer is not yet well studied. We evaluated dietary intakes of quercetin and risk of colorectal cancer in a large case-control study conducted in metropolitan Detroit, Michigan (N = 2664). The protective effects of quercetin intake, as assessed by a food frequency questionnaire, were confined to risk of proximal colon cancer. Stratified analyses showed that the protective effects of quercetin on risk of proximal colon cancer were significant only when fruit intake or the Healthy Eating Index score was high, or when tea intake was low, with odds ratios (OR) for the highest vs. the lowest quartile of 0.49, 0.44, and 0.51, respectively. Increased quercetin intake had no protective effects when tea intake was high. Interestingly, increased intake of quercetin was associated with increased risk of distal colon cancer when total fruit intake was low (OR for the highest vs. the lowest quartile = 1.99). These results suggest that quercetin can have disparate effects on colon cancer risk depending on whether dietary intakes of fruit or tea are high, and that quercetin had protective effects only on proximal, not distal, colon cancer.