Colorectal Cancer Statistics From the Veterans Affairs Central Cancer Registry

Gut microbiota and their derivatives in the progression of colorectal cancer: Mechanisms of action, genome and epigenome contributions

Gut microbiota interacts with host epithelial cells and regulates many physiological functions such as genetics, epigenetics, metabolism of nutrients, and immune functions. Dietary factors may also be involved in the etiology of colorectal cancer (CRC), especially when an unhealthy diet is consumed with excess calorie intake and bad practices like smoking or consuming a great deal of alcohol. Bacteria including Fusobacterium nucleatum, Enterotoxigenic Bacteroides fragilis (ETBF), and Escherichia coli (E. coli) actively participate in the carcinogenesis of CRC. Gastrointestinal tract with chronic inflammation and immunocompromised patients are at high risk for CRC progression. Further, the gut microbiota is also involved in Geno-toxicity by producing toxins like colibactin and cytolethal distending toxin (CDT) which cause damage to double-stranded DNA. Specific microRNAs can act as either tumor suppressors or oncogenes depending on the cellular environment in which they are expressed. The current review mainly highlights the role of gut microbiota in CRC, the mechanisms of several factors in carcinogenesis, and the role of particular microbes in colorectal neoplasia.

Gut microbiota and epigenetics in colorectal cancer: implications for carcinogenesis and therapeutic intervention

Colorectal cancer (CRC) is a leading cause of cancer-related deaths worldwide. The occurrence of CRC is associated with various genetic and epigenetic mutations in intestinal epithelial cells that transform them into adenocarcinomas. There is increasing evidence indicating the gut microbiota plays a crucial role in the regulation of host physiological processes. Alterations in gut microbiota composition are responsible for initiating carcinogenesis through diverse epigenetic modifications, including histone modifications, ncRNAs and DNA methylation. This work was designed to comprehensively review recent findings to provide insight into the associations between the gut microbiota and CRC at an epigenetic level. These scientific insights can be used in the future to develop effective strategies for early detection and treatment of CRC.

Lobe-specific lymph node sampling is associated with lower risk of cancer recurrence

Objective

Adequate intraoperative lymph node (LN) assessment is a critical component of early-stage non-small cell lung cancer (NSCLC) resection. The National Comprehensive Cancer Network and the American College of Surgeons Commission on Cancer (CoC) recommend station-based sampling minimums agnostic to tumor location. Other institutions advocate for lobe-specific LN sampling strategies that consider the anatomic likelihood of LN metastases. We examined the relationship between lobe-specific LN assessment and long-term outcomes using a robust, highly curated cohort of stage I NSCLC patients.

Methods

We performed a cohort study using a uniquely compiled dataset from the Veterans Health Administration and manually abstracted data from operative and pathology reports for patients with clinical stage I NSCLC (2006-2016). For simplicity in comparison, we included patients who had right upper lobe (RUL) or left upper lobe (LUL) tumors. Based on modified European Society of Thoracic Surgeons guidelines, lobe-specific sampling was defined for RUL tumors (stations 2, 4, 7, and 10 or 11) and LUL tumors (stations 5 or 6, 7, and 10 or 11). Our primary outcome was the risk of cancer recurrence, as assessed by Fine and Gray competing risks modeling. Secondary outcomes included overall survival (OS) and pathologic upstaging. Analyses were adjusted for relevant patient, disease, and treatment variables.

Results

Our study included 3534 patients with RUL tumors and 2667 patients with LUL tumors. Of these, 277 patients (7.8%) with RUL tumors and 621 patients (23.2%) with LUL tumors met lobe-specific assessment criteria. Comparatively, 34.7% of patients met the criteria for count-based assessment, and 25.8% met the criteria for station-based sampling (ie, any 3 N2 stations and 1 N1 station). Adherence to lobe-specific assessment was associated with lower cumulative incidence of recurrence (adjusted hazard ratio [aHR], 0.83; 95% confidence interval [CI], 0.70-0.98) and a higher likelihood of pathologic upstaging (aHR, 1.49; 95% CI, 1.20-1.86). Lobe-specific assessment was not associated with OS.

Conclusions

Adherence to intraoperative LN sampling guidelines is low. Lobe-specific assessment is associated with superior outcomes in early-stage NSCLC. Quality metrics that assess adherence to intraoperative LN sampling, such as the CoC Operative Standards manual, also should consider lobe-specific criteria.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Development and Validation of the VA Lung Cancer Mortality (VALCAN-M) Score for 90-Day Mortality Following Surgical Treatment of Clinical Stage I Lung Cancer

OBJECTIVE

The aim was to develop and validate the Veterans Administration (VA) Lung Cancer Mortality (VALCAN-M) score, a risk prediction model for 90-day mortality following surgical treatment of clinical stage I nonsmall-cell lung cancer (NSCLC).

BACKGROUND

While surgery remains the preferred treatment for functionally fit patients with early-stage NSCLC, less invasive, nonsurgical treatments have emerged for high-risk patients. Accurate risk prediction models for postoperative mortality may aid surgeons and other providers in optimizing patient-centered treatment plans.

METHODS

We performed a retrospective cohort study using a uniquely compiled VA data set including all Veterans with clinical stage I NSCLC undergoing surgical treatment between 2006 and 2016. Patients were randomly split into derivation and validation cohorts. We derived the VALCAN-M score based on multivariable logistic regression modeling of patient and treatment variables and 90-day mortality.

RESULTS

A total of 9749 patients were included (derivation cohort: n=6825, 70.0%; validation cohort: n=2924, 30.0%). The 90-day mortality rate was 4.0% (n=390). The final multivariable model included 11 factors that were associated with 90-day mortality: age, body mass index, history of heart failure, forced expiratory volume (% predicted), history of peripheral vascular disease, functional status, delayed surgery, American Society of Anesthesiology performance status, tumor histology, extent of resection (lobectomy, wedge, segmentectomy, or pneumonectomy), and surgical approach (minimally invasive or open). The c statistic was 0.739 (95% CI=0.708-0.771) in the derivation cohort.

CONCLUSIONS

The VALCAN-M score uses readily available treatment-related variables to reliably predict 90-day operative mortality. This score can aid surgeons and other providers in objectively discussing operative risk among high-risk patients with clinical stage I NSCLC considering surgery versus other definitive therapies.

Association between imaging surveillance frequency and outcomes following surgical treatment of early-stage lung cancer

BACKGROUND

Recent studies have suggested that more frequent postoperative surveillance imaging via computed tomography following lung cancer resection may not improve outcomes. We sought to validate these findings using a uniquely compiled dataset from the Veterans Health Administration, the largest integrated health-care system in the United States.

METHODS

We performed a retrospective cohort study of veterans with pathologic stage I non-small cell lung cancer receiving surgery (2006-2016). We assessed the relationship between surveillance frequency (chest computed tomography scans within 2 years after surgery) and recurrence-free survival and overall survival.

RESULTS

Among 6171 patients, 3047 (49.4%) and 3124 (50.6%) underwent low-frequency (<2 scans per year; every 6-12 months) and high-frequency (≥2 scans per year; every 3-6 months) surveillance, respectively. Factors associated with high-frequency surveillance included being a former smoker (vs current; adjusted odds ratio [aOR] = 1.18, 95% confidence interval [CI] = 1.05 to 1.33), receiving a wedge resection (vs lobectomy; aOR = 1.21, 95% CI = 1.05 to 1.39), and having follow-up with an oncologist (aOR = 1.58, 95% CI = 1.42 to 1.77), whereas African American race was associated with low-frequency surveillance (vs White race; aOR = 0.64, 95% CI = 0.54 to 0.75). With a median (interquartile range) follow-up of 7.3 (3.4-12.5) years, recurrence was detected in 1360 (22.0%) patients. High-frequency surveillance was not associated with longer recurrence-free survival (adjusted hazard ratio = 0.93, 95% CI = 0.83 to 1.04, P = .22) or overall survival (adjusted hazard ratio = 1.04, 95% CI = 0.96 to 1.12, P = .35).

CONCLUSIONS

We found that high-frequency surveillance does not improve outcomes in surgically treated stage I non-small cell lung cancer. Future lung cancer treatment guidelines should consider less frequent surveillance imaging in patients with stage I disease.

Aryl hydrocarbon receptor nuclear translocator limits the recruitment and function of regulatory neutrophils against colorectal cancer by regulating the gut microbiota

BACKGROUND

Although the role and mechanism of neutrophils in tumors have been widely studied, the precise effects of aryl hydrocarbon receptor nuclear translocator (ARNT) on neutrophils remain unclear. In this study, we investigated the roles of ARNT in the function of CD11b⁺Gr1⁺ neutrophils in colitis-associated colorectal cancer.

METHODS

Wild-type (WT), ARNT myeloid-specific deficient mice and a colitis-associated colorectal cancer mouse model were used in this study. The level and functions of CD11b⁺Gr1⁺ cells were evaluated by flow cytometry and confocal microscopy.

RESULTS

We found that ARNT deficiency drives neutrophils recruitment, neutrophil extracellular trap (NET) development, inflammatory cytokine secretion and suppressive activities when cells enter the periphery from bone marrow upon colorectal tumorigenesis. ARNT deficiency displays similar effects to aryl hydrocarbon receptor (AHR) deficiency in neutrophils. CXCR2 is required for NET development, cytokine production and recruitment of neutrophils but not the suppressive activities induced by Arnt^-/- in colorectal cancer. The gut microbiota is essential for functional alterations in Arnt^-/- neutrophils to promote colorectal cancer growth. The colorectal cancer effects of Arnt^-/- neutrophils were significantly restored by mouse cohousing or antibiotic treatment. Intragastric administration of the feces of Arnt^-/- mice phenocopied their colorectal cancer effects.

CONCLUSION

Our results defined a new role for the transcription factor ARNT in regulating neutrophils recruitment and function and the gut microbiota with implications for the future combination of gut microbiota and immunotherapy approaches in colorectal cancer.

Comparison Between Veteran and Non-Veteran Populations With Clinical Stage I Non-small Cell Lung Cancer Undergoing Surgery

OBJECTIVE

The aim of this study was to compare quality of care and outcomes between Veteran and non-Veteran patients undergoing surgery for clinical stage I non-small cell lung cancer (NSCLC).

BACKGROUND

Prior studies and the lay media have questioned the quality of care that Veterans with lung cancer receive through the VHA. We hypothesized Veterans undergoing surgery for early-stage NSCLC receive high quality care and have similar outcomes compared to the general population.

METHODS

We performed a retrospective cohort study of patients with clinical stage I NSCLC undergoing resection from 2006 to 2016 using a VHA dataset. Propensity score matching for baseline patient- and tumor-related variables was used to compare operative characteristics and outcomes between the VHA and the National Cancer Database (NCDB).

RESULTS

The unmatched cohorts included 9981 VHA and 176,304 NCDB patients. The VHA had more male, non-White patients with lower education levels, higher incomes, and higher Charlson/Deyo scores. VHA patients had inferior unadjusted 30-day mortality (VHA 2.1% vs NCDB 1.7%, P = 0.011) and median overall survival (69.0 vs 88.7 months, P < 0.001). In the propensity matched cohort of 6792 pairs, VHA patients were more likely to have minimally invasive operations (60.0% vs 39.6%, P < 0.001) and only slightly less likely to receive lobectomies (70.1% vs 70.7%, P = 0.023). VHA patients had longer lengths of stay (8.1 vs 7.1 days, P < 0.001) but similar readmission rates (7.7% vs 7.0%, P = 0.132). VHA patients had significantly better 30-day mortality (1.9% vs 2.8%, P < 0.001) and median overall survival (71.4 vs 65.2 months, P < 0.001).

CONCLUSIONS

Despite having more comorbidities, Veterans receive exceptional care through the VHA with favorable outcomes, including significantly longer overall survival, compared to the general population.

An AI-Based Colonic Polyp Classifier for Colorectal Cancer Screening Using Low-Dose Abdominal CT

Among the non-invasive Colorectal cancer (CRC) screening approaches, Computed Tomography Colonography (CTC) and Virtual Colonoscopy (VC), are much more accurate. This work proposes an AI-based polyp detection framework for virtual colonoscopy (VC). Two main steps are addressed in this work: automatic segmentation to isolate the colon region from its background, and automatic polyp detection. Moreover, we evaluate the performance of the proposed framework on low-dose Computed Tomography (CT) scans. We build on our visualization approach, Fly-In (FI), which provides "filet"-like projections of the internal surface of the colon. The performance of the Fly-In approach confirms its ability with helping gastroenterologists, and it holds a great promise for combating CRC. In this work, these 2D projections of FI are fused with the 3D colon representation to generate new synthetic images. The synthetic images are used to train a RetinaNet model to detect polyps. The trained model has a 94% f1-score and 97% sensitivity. Furthermore, we study the effect of dose variation in CT scans on the performance of the the FI approach in polyp visualization. A simulation platform is developed for CTC visualization using FI, for regular CTC and low-dose CTC. This is accomplished using a novel AI restoration algorithm that enhances the Low-Dose CT images so that a 3D colon can be successfully reconstructed and visualized using the FI approach. Three senior board-certified radiologists evaluated the framework for the peak voltages of 30 KV, and the average relative sensitivities of the platform were 92%, whereas the 60 KV peak voltage produced average relative sensitivities of 99.5%.

Assessment of Updated Commission on Cancer Guidelines for Intraoperative Lymph Node Sampling in Early Stage NSCLC

INTRODUCTION

The American College of Surgeons Commission on Cancer recently updated its sampling recommendations for early stage NSCLC from at least 10 lymph nodes to at least one N1 (hilar) and three N2 (mediastinal) lymph node stations. Nevertheless, intraoperative lymph node sampling minimums remain subject to debate. We sought to evaluate these guidelines in patients with early stage NSCLC.

METHODS

We performed a cohort study using a uniquely compiled data set from the Veterans Health Administration. We manually abstracted data from operative notes and pathology reports of patients with clinical stage I NSCLC receiving surgery (2006-2016). Adequacy of lymph node sampling was defined using count-based (≥10 lymph nodes) and station-based (≥three N2 and one N1 nodal stations) minimums. Our primary outcome was recurrence-free survival. Secondary outcomes were overall survival and pathologic upstaging.

RESULTS

The study included 9749 patients. Count-based and station-based sampling guidelines were achieved in 3302 (33.9%) and 2559 patients (26.3%), respectively, with adherence to either sampling guideline increasing over time from 35.6% (2006) to 49.1% (2016). Adherence to station-based sampling was associated with improved recurrence-free survival (multivariable-adjusted hazard ratio = 0.815, 95% confidence interval: 0.667-0.994, p = 0.04), whereas adherence to count-based sampling was not (adjusted hazard ratio = 0.904, 95% confidence interval: 0.757-1.078, p = 0.26). Adherence to either station-based or count-based guidelines was associated with improved overall survival and higher likelihood of pathologic upstaging.

CONCLUSIONS

Our study supports station-based sampling minimums (≥three N2 and one N1 nodal stations) for early stage NSCLC; however, the marginal benefit compared with count-based guidelines is minimal. Further efforts to promote widespread adherence to intraoperative lymph node sampling minimums are critical for improving patient outcomes after curative-intent lung cancer resection.

Racial Disparities in the Surgical Treatment of Clinical Stage I Non-Small Cell Lung Cancer Among Veterans

BACKGROUND

Prior studies in the civilian population have reported racial disparities in lung cancer outcomes following surgical treatment, including inferior quality of care and worse survival. It is unclear if racial disparities exist in the Veterans Health Administration (VHA), the largest integrated health care system in the United States.

RESEARCH QUESTION

Do racial disparities affect early-stage non-small cell lung cancer (NSCLC) outcomes following surgical treatment within the VHA?

STUDY DESIGN AND METHODS

This retrospective cohort study was conducted in veterans with clinical stage I NSCLC undergoing surgical treatment in the VHA system. Demographic characteristics, access to care, surgical quality measures, and short- and long-term oncologic outcomes between White and Black veterans were evaluated.

RESULTS

From 2006 to 2016, a total of 18,800 veterans with clinical stage I NSCLC were included. The rates of definitive surgical treatment were similar between Black (57.3%) and White (58.1%) veterans (P = .42). The final study cohort included 9,842 patients receiving surgical treatment, of whom 8,356 (84.9%) were White and 1,486 (15.1%) were Black. Black patients were younger and more likely to smoke, although comorbidities were similar between the two groups. Black patients were somewhat less likely to receive adequate lymph node sampling (30.6% vs 33.3%; P = .050); however, other access-to-care metrics and surgical quality measures, including rates of anatomic lobectomy (71.9% vs 69.4%; P = .189) and positive margins (3.2% vs 3.1%; P = .955), were similar between the two groups. Although Black veterans were less likely to experience major postoperative complications, there was no difference in 30-day readmission, 30-day mortality, or disease-free survival between the two groups. Black patients had significantly better risk-adjusted overall survival (hazard ratio, 0.802; 95% CI, 0.729-0.883; P < .001).

INTERPRETATION

Among veterans with NSCLC undergoing surgical treatment through the VHA, Black patients received comparable care with equivalent if not superior outcomes compared with White patients.

Increased relative proportions of advanced melanoma among Veterans: a comparative analysis with the SEER registry

BACKGROUND

The Surveillance, Epidemiology, and End Results (SEER) program reflects one-third of the U.S.

POPULATION

However, SEER may not be generalizable to the Veteran population. Since Veterans comprise a high-risk population, this discrepancy may limit our understanding of melanoma epidemiology in such high-risk populations.

OBJECTIVE

To assess differences in demographics, tumor characteristics, and melanoma-specific survival in Veterans compared to the general population.

METHODS

Data were collected from the Veterans Affairs Central Cancer Registry (VACCR) and SEER (18 registries) from 2009 to 2017.

RESULTS

15,334 Veterans and 166,265 SEER patients with melanoma were identified. Veterans were more likely to present with regional or distant disease (17.5% vs. 13.0% in SEER). 5-year melanoma specific survival (MSS) was lower across all ages, except those diagnosed at ≥80 years, in VACCR relative to SEER. Similarly, from 2009-2017, MSS by stage was lower across all stages in VACCR. However, for stage IV melanomas diagnosed in 2015-2017, compared to 2011-2014, 2-year MSS increased from 37.8% to 51.5% in VACCR versus 36.4% to 44.8% in SEER.

LIMITATIONS

Unique Veteran demographics and missing data inherent to VACCR.

CONCLUSION

Compared to SEER, Veterans with melanoma were diagnosed at later stages, but both exhibited recent improvement in stage IV MSS.

Combined Effects of Resveratrol and Vitamin E From Peanut Seeds and Sprouts on Colorectal Cancer Cells

Resveratrol (RES) and Vitamin E (VE) are anti-cancer active ingredients with relatively high content in peanut seeds and sprouts. This study aimed to determine the synergistic inhibitory effect of RES and VE on colorectal cancer. Using 5-FU as a positive drug control, the effect of RES combined with VE on HCT-8 cells was determined, and cell viability was detected using the cell-counting kit 8 (CCK8) method. Cell morphology changes were observed using optical microscopy. Cell migration ability was evaluated by the scratch test, while cell colonies were determined by the cloning test formation ability. Apoptosis status was assessed by flow cytometry and nuclear staining by DAPI, and the expression level of apoptosis-related proteins was determined by western blotting. Compared with the single component group, the RES combined with VE group significantly inhibited the growth and proliferation of HCT-8 intestinal cancer cells in vitro. The RES combined with VE group had a greater impact on cell morphology changes and cell colony formation and significantly reduced cell migration ability and intestinal cancer cell apoptosis (p < 0.05). Additionally, combined treatment with RES and VE significantly upregulated the expression of pro-apoptotic proteins BAX, caspase-3, caspase-8, and caspase-9, and downregulated the expression of anti-apoptotic protein BCL-2, compared to the single component treatment. RES combined with VE is effective in promoting intestinal cancer cell apoptosis. This study demonstrated the significant positive synergy of RES and VE on HCT-8 cells, providing a new perspective for more effective use of RES.

Association of Adherence to Quality Metrics with Recurrence or Mortality among Veterans with Colorectal Cancer

BACKGROUND

The National Comprehensive Cancer Network has defined metrics for colorectal cancer; however, the association of metric adherence with patient clinical outcomes remains underexplored. The study aim was to evaluate the association of National Comprehensive Cancer Network metric adherence with recurrence and mortality in Veterans with nonmetastatic colorectal cancer.

METHODS

Veterans with stage I-III colorectal cancer who underwent non-emergent resection from 2001 to 2015 at a single Veterans Affairs Medical Center were included. The primary predictor was completion of eligible National Comprehensive Cancer Network metrics. The primary outcome was a composite of recurrence or all-cause death in three phases of care: surgical (up to 6 months after resection), treatment (6-18 months after resection), and surveillance (18 months-3 years after resection). Hazard ratios were estimated via Cox proportional hazards regression in a propensity score-weighted cohort.

RESULTS

A total of 1107 electronic medical records of patients undergoing colorectal surgery were reviewed, and 379 patients were included (301 colon and 78 rectal cancer). In the surgical phase, the weighted analysis yielded a hazard ratio of 0.37 (95% confidence interval 0.12-1.13) for metric-adherent patients compared with non-adherent patients. In the treatment and surveillance phases, the hazard ratios for metric-adherent care were 0.68 (95% confidence interval 0.25-1.85) and 0.91 (95% confidence interval 0.31-2.68), respectively.

CONCLUSIONS

The National Comprehensive Cancer Network guideline metric adherence was associated with a lower rate of recurrence and death in the surgical phase of care among stage I-III patients with resected colorectal cancer.

Association of Health-Care System with Prostate Cancer-Specific Mortality in African American and Non-Hispanic White Men

BACKGROUND

Disparities in prostate cancer-specific mortality (PCSM) between African American and non-Hispanic White (White) patients have been attributed to biological and systemic factors. We evaluated drivers of these disparities in the Surveillance, Epidemiology and End Results (SEER) national registry and an equal-access system, the Veterans Health Administration (VHA).

METHODS

We identified African American and White patients diagnosed with prostate cancer between 2004-2015 in SEER (N = 311,691) and the VHA (N = 90,749). We analyzed the association between race and metastatic disease at presentation using multivariable logistic regression adjusting for sociodemographic factors, and PCSM using sequential competing-risks regression adjusting for disease and sociodemographic factors.

RESULTS

The median follow-up was 5.3 years in SEER and 4.7 years in the VHA. African American men were more likely than White men to present with metastatic disease in SEER (adjusted odds ratio = 1.23, 95% confidence interval [CI] = 1.17-1.30), but not in the VHA (adjusted odds ratio = 1.07, 95% CI = 0.98-1.17). African American versus White race was associated with an increased risk of PCSM in SEER (subdistribution hazard ratio [SHR] = 1.32, 95% CI = 1.10-1.60), but not in the VHA (SHR = 1.00, 95% CI: 0.93-1.08). Adjusting for disease extent, PSA, and Gleason score eliminated the association between race and PCSM in SEER (aSHR 1.04, 95% CI 0.93-1.16).

CONCLUSIONS

Racial disparities in PCSM were present in a nationally representative registry, but not in an equal-access healthcare system, due to differences in advanced disease at presentation. Strategies to increase healthcare access may bridge the racial disparity in outcomes. Longer follow-up is needed to fully assess mortality outcomes.Disparities between African American and non-Hispanic White (White) patients in cancer-specific mortality have been described across numerous cancer types and healthcare systems[1-5]. The survival gap between African American and White patients with prostate cancer has been well-characterized, with two-fold higher prostate cancer-specific mortality (PCSM) rates among African American patients depending on the setting[1, 6-10]. This disparity has been attributed to differences in prostate cancer biology in African American men, in addition to systemic factors in mediating this disparity, such as differential access to healthcare, Prostate-Specific Antigen (PSA) screening, and distrust in the healthcare system[1, 11-16].The Veterans Health Administration (VHA) is a relatively equal-access healthcare system that treats a large, ethnically diverse population of veterans. The Surveillance, Epidemiology and End Results (SEER) program is a national cancer registry program that collects data from the general United States (US) population. The goals of the present investigation were to 1) Compare PCSM between African American and White men within SEER and the VHA and 2) Identify modifiable system-level contributors to these disparities. We hypothesized that PCSM would be comparable among African American and White men in an equal-access setting, the VHA, but not in a national registry, SEER, and that this disparity in SEER would be in part driven by more advanced disease at presentation.

Temozolomide modulates the expression of miRNAs in colorectal cancer

Cancer is the second leading cause of death globally, where nearly 1 in 6 deaths is due to cancer, with 70% of all deaths from cancer occur in low- and middle-income countries. The overall lifetime risk of developing colorectal cancer is 1 in 22 in men and 1 in 24 in women. In this work, we aimed to evaluate the role of temozolomide (TMZ) in controlling colon cancer cells (CRC) via regulating the miRnome. For this purpose, CRC cells (CaCo-2) were treated with 50 µM of TMZ for 48 h. Cell count using trypan test and cytotoxicity using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) were carried out, and the obtained results indicated a significant decrease in cell count (p = 0.029), and in the cell viability (p = 0.0019). Cell cycle analysis was performed using flow cytometer, and results showed that TMZ arrested CRC cells at G2/M phase. A total of 84 miRNAs were profiled using real time PCR, and the results indicated that TMZ treatment upregulated 15 of 84 miRNAs panel profiled and downregulated the rest. The TMZ-upregulated/downregulated miRNAs were predicted to interact with many epigenetic-related proteins i.e., DNMTs, EZH2, and SUV31H1. This study shed some light on the role of TMZ in regulating the miRnome of CRC and hence in different types of cancers.

Identifying Potential Biomarkers in Colorectal Cancer and Developing Non-invasive Diagnostic Models Using Bioinformatics Approaches

Background: Colorectal cancer (CRC) is one of the most frequent causes of gastrointestinal tumors. Due to the invasiveness of the current diagnostic methods, there is an urgent need to develop non-invasive diagnostic approaches for CRC. The exact mechanisms and the most important genes associated with the development of CRC are not fully demonstrated. Objectives: This study aimed to identify differentially expressed miRNAs (DEMs), key genes, and their regulators associated with the pathogenesis of CRC. The signaling pathways and biological processes (BPs) that were significantly affected in CRC were also indicated. Moreover, two non-invasive models were constructed for CRC diagnosis. Methods: The miRNA dataset GSE59856 was downloaded from the Gene Expression Omnibus (GEO) database and analyzed to identify DEMs in CRC patients compared with healthy controls (HCs). A protein-protein interaction (PPI) network was built and analyzed. Significant clusters in the PPI networks were identified, and the BPs and pathways associated with these clusters were studied. The hub genes in the PPI network, as well as their regulators were identified. Results: A total of 569 DEMs were demonstrated with the criteria of P value <0.001. A total of 110 essential genes and 30 modules were identified in the PPI network. Functional analysis revealed that 1005 BPs, 9 molecular functions (MFs), 14 cellular components (CCs), and 887 pathways were significantly affected in CRC. A total of 22 transcription factors (TFs) were demonstrated as the regulators of the hubs. Conclusion: Our results may provide new insight into the pathogenesis of CRC and advance the diagnostic and therapeutic methods of the disease. However, confirmation is required in the future.

An RCT of Fecal Immunochemical Test Colorectal Cancer Screening in Veterans Without Recent Primary Care

INTRODUCTION

The use of screening can prevent death from colorectal cancer, yet people without regular healthcare visits may not realize the benefits of this preventive intervention. The objective of this study was to determine the effectiveness of a mailed screening invitation or mailed fecal immunochemical test in increasing colorectal cancer screening uptake in veterans without recent primary care encounters.

STUDY DESIGN

Three-arm pragmatic randomized trial.

SETTING/PARTICIPANTS

Participants were screening-eligible veterans aged 50-75 years, without a recent primary care visit who accessed medical services at the Corporal Michael J. Crescenz Veteran Affairs Medical Center between January 1, 2017, and July 31, 2017. All data were analyzed from March 1, 2018, to July 31, 2018.

INTERVENTION

Participants were randomized to (1) usual opportunistic screening during a healthcare visit (n=260), (2) mailed invitation to screen and reminder phone calls (n=261), or (3) mailed fecal immunochemical test outreach plus reminder calls (n=61).

MAIN OUTCOME MEASURES

The main outcome under investigation was the completion of colorectal cancer screening within 6 months after randomization.

RESULTS

Of 782 participants in the trial, 53.9% were aged 60-75 years and 59.7% were African American. The screening rate was higher in the mailed fecal immunochemical test group (26.1%) compared with usual care (5.8%) (rate difference=20.3%, 95% CI=14.3%, 26.3%; RR=4.52, 95% CI=2.7, 7.7) or screening invitation (7.7%) (rate difference=18.4%, 95% CI=12.2%, 24.6%; RR=3.4, 95% CI=2.1, 5.4). Screening completion rates were similar between invitation and usual care (rate difference=1.9%, 95% CI= -2.4%, 6.2%; RR=1.3, 95% CI=0.7, 2.5).

CONCLUSIONS

Mailed fecal immunochemical test screening promotes colorectal cancer screening participation among veterans without a recent primary care encounter. Despite the addition of reminder calls, an invitation letter was no more effective in screening participation than screening during outpatient appointments.

TRIAL REGISTRATION

This study is registered at clinicaltrials.gov NCT02584998.

MicroRNA-215 Regulates the Apoptosis of HCT116 Colon Cancer Cells by Inhibiting X-Linked Inhibitor of Apoptosis Protein

Background: X-linked inhibitor of apoptosis protein (XIAP) is the strongest member of the family of inhibitor of apoptosis protein. Studies found that the expression of XIAP in colon cancer tissue was significantly higher than that in adjacent tissues. Studies have shown that the expression of microRNA-215 (miR-215) was significantly lower than that of the adjacent tissues. This study investigated whether dysregulated miR-215 and XIAP play important roles in colon cancer cell apoptosis and the incidence of colon cancer. Materials and Methods: Forty-two patients with colorectal cancer (CRC) diagnosed and treated in the authors' hospital were selected. Human CRC cell line HCT116 and normal colonic mucosal epithelial cells (CMECs) were used. Luciferase reporter gene vector was constructed and dual-luciferase reporter gene assay was performed. HCT116 cells were cultured in vitro and divided into five groups: mimic normal control (NC) group, miR-215 mimic group, si-NC group, si-XIAP group, and miR-215 mimic + si-XIAP group. Western blot and polymerase chain reaction were conducted to examine XIAP and caspase-3. Apoptosis was detected by flow cytometry and cell proliferation was detected by cell counting kit-8 assay. Results: Compared with the adjacent tissues, the expression of miR-215 in colon cancer tissue was significantly lower, whereas the expression of XIAP in colon cancer tissue was significantly higher. The apoptosis rate and miR-215 expression level of HCT116 cells were lower than that of normal CMECs, whereas XIAP expression was significantly higher than that in normal colon mucosa epithelial cells. MiR-215 targeted the 3'-untranslated regions of XIAP and inhibited its expression. Overexpressing miR-215 and (or) silencing XIAP expression could significantly enhance the activity of caspase-9 and caspase-3, and promote the apoptosis of HCT116 cells. Conclusion: MiR-215 inhibited the expression of XIAP and promoted the apoptosis of HCT116 cells.

Construction of a CXC Chemokine-Based Prediction Model for the Prognosis of Colon Cancer

Colon cancer is the third most common cancer, with a high incidence and mortality. Construction of a specific and sensitive prediction model for prognosis is urgently needed. In this study, profiles of patients with colon cancer with clinical and gene expression data were downloaded from Gene Expression Omnibus and The Cancer Genome Atlas (TCGA). CXC chemokines in patients with colon cancer were investigated by differential expression gene analysis, overall survival analysis, receiver operating characteristic analysis, gene set enrichment analysis (GSEA), and weighted gene coexpression network analysis. CXCL1, CXCL2, CXCL3, and CXCL11 were upregulated in patients with colon cancer and significantly correlated with prognosis. The area under curve (AUC) of the multigene forecast model of CXCL1, CXCL11, CXCL2, and CXCL3 was 0.705 in the GSE41258 dataset and 0.624 in TCGA. The prediction model was constructed using the risk score of the multigene model and three clinicopathological risk factors and exhibited 92.6% and 91.8% accuracy in predicting 3-year and 5-year overall survival of patients with colon cancer, respectively. In addition, by GSEA, expression of CXCL1, CXCL11, CXCL2, and CXCL3 was correlated with several signaling pathways, including NOD-like receptor, oxidative phosphorylation, mTORC1, interferon-gamma response, and IL6/JAK/STAT3 pathways. Patients with colon cancer will benefit from this prediction model for prognosis, and this will pave the way to improve the survival rate and optimize treatment for colon cancer.

CDK1 and CDC20 overexpression in patients with colorectal cancer are associated with poor prognosis: evidence from integrated bioinformatics analysis

BACKGROUND

Colorectal cancer (CRC) is one of the most common malignancies of the digestive system, which causes severe financial burden worldwide. However, the specific mechanisms involved in CRC are still unclear.

METHODS

To identify the significant genes and pathways involved in the initiation and progression of CRC, the microarray dataset GSE126092 was downloaded from Gene Expression Omnibus (GEO) database, and then, the data was analyzed to identify differentially expressed genes (DEGs). Subsequently, the Gene Ontology (GO) annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were performed on these DEGs using the DAVID database, and the protein-protein interaction (PPI) network was constructed using the STRING database and analyzed using the Cytoscape software. Finally, hub genes were screened, and the survival analysis was performed on these hub genes using the Kaplan-Meier curves in the cBioPortal database.

RESULTS

In total, 937 DEGs were obtained, including 316 upregulated genes and 621 downregulated genes. GO analysis revealed that the DEGs were mostly enriched in terms of nuclear division, organelle fission, cell division, and cell cycle process. KEGG pathway analysis showed that the DEGs were mostly enriched in cell cycle, oocyte meiosis, cytokine-cytokine receptor interaction, and cGMP-PKG signaling pathway. The PPI network comprised 608 nodes and 3100 edges, and 4 significant modules and 10 hub genes with the highest degree were identified using the Cytoscape software. Finally, survival analysis showed that overexpression of CDK1 and CDC20 in patients with CRC were statistically associated with worse overall survival.

CONCLUSIONS

This bioinformatics analysis revealed that CDK1 and CDC20 might be candidate targets for diagnosis and treatment of CRC, which provided valuable clues for CRC.

Colorectal cancer: The epigenetic role of microbiome

Colorectal cancer (CRC) is the third most common cancer in men (746000 cases per year) and the second most common cancer in women globally (614000 cases per year). The incidence rate of CRC in developed countries (737000 cases per year) is higher than that in less developed countries (624000 cases per year). CRC can arise from genetic causes such as chromosomal instability and microsatellite instability. Several etiologic factors underlie CRC including age, diet, and lifestyle. Gut microbiota represent a proven cause of the disease, where they play pivotal roles in modulating and reshaping the host epigenome. Several active microbial metabolites have been found to drive carcinogenesis, invasion, and metastasis via modifying both the methylation landscape along with histone structure in intestinal cells. Gut microbiota, in response to diet, can exert both beneficial and harmful functions in humans, according to the intestinal balance of number and types of these bacteria. Although the intestinal microbial community is diverse among individuals, these microbes cumulatively produce 100-fold more proteins than the human genome itself, which calls for further studies to elaborate on the complicated interaction between these microorganisms and intestinal cells. Therefore, understanding the exact role that gut microbiota play in inducing CRC will help attain reliable strategies to precisely diagnose and treat this fatal disease.

Utilization of the Veterans Affairs Central Cancer Registry to evaluate lung cancer outcomes

Lung cancer is one of the most common and difficult to treat cancers. Veterans are disproportionately affected by lung cancer, as approximately 20% of all cancers diagnosed within the Veteran Affairs health system are lung cancers. Many Veterans have extensive comorbidities, and thus they are often excluded from clinical trials based on this and other eligibility criteria. Thus, while clinical trials are the gold standard to guide treatment decisions, many Veterans' clinical situations will not align with clinical trial criteria. The Department of Veterans Affairs has established a Central Cancer Registry to aid in evaluation of cancer outcomes and other studies, and data in the registry date back to 1995. This has provided a rich source of data for outcome-based and other research. Here, we highlight studies that utilized the Veterans Affairs Central Cancer Registry to analyze lung cancer outcomes in Veterans treated within the Veterans Affairs health system.

Cardiovascular disease-related chronic conditions among Veterans Affairs nonmetastatic colorectal cancer survivors: a matched case-control analysis

Purpose

The growing number of colorectal cancer (CRC) survivors often have multiple chronic conditions. Comparing nonmetastatic CRC survivors and matched noncancer controls, our objectives were to determine the odds of CRC survivors being diagnosed with cardiovascular disease (CVD)-related chronic conditions and their likelihood of control during the year after CRC diagnosis.

Patients and methods

We retrospectively identified patients diagnosed with nonmetastatic CRC in the Veterans Affairs health care system from fiscal years 2009 to 2012 and matched each with up to 3 noncancer control patients. We used logistic regression to assess differences in the likelihood of being diagnosed with CVD-related chronic conditions and control between nonmetastatic CRC survivors and noncancer controls.

Results

We identified 9,758 nonmetastatic CRC patients and matched them to 29,066 noncancer controls. At baseline, 69.4% of CRC survivors and their matched controls were diagnosed with hypertension, 52.4% with hyperlipidemia, and 36.7% with diabetes. Compared to matched noncancer controls, CRC survivors had 57% higher odds of being diagnosed with hypertension (OR=1.57, 95% CI=1.49–1.64) and 7% higher odds of controlled blood pressure (OR=1.07, 95% CI 1.02, 1.13) in the subsequent year. Compared to matched noncancer control patients, CRC survivors had half the odds of being diagnosed with hyperlipidemia (OR=0.50, 95% CI=0.48–0.52) and lower odds of low-density lipoprotein (LDL) control (OR 0.88, 95% CI 0.81–0.94). There were no significant differences between groups for diabetes diagnoses or control.

Conclusion

Compared to noncancer controls, nonmetastatic CRC survivors have 1) greater likelihood of being diagnosed with hypertension and worse blood pressure control in the year following diagnosis; 2) lower likelihood of being diagnosed with hyperlipidemia or LDL control; and 3) comparable diabetes diagnoses and control. There may be a need for hypertension control interventions targeting cancer survivors.

Efficacy of intestinal obstruction stent combined with laparoscopic surgery and neoadjuvant chemotherapy in patients with obstructive colorectal cancer

There is still controversy on the surgical treatment of obstructive colorectal cancer worldwide. No accurate research has been reported to propose which method is the most suitable for patients with obstructive colorectal cancer. Therefore, comparison of efficacy of intestinal stent and trans-anal ileus catheter combined with laparoscopic surgery and neoadjuvant chemotherapy respectively in patients with obstructive colorectal cancer was carried out to provide reference and guidance for the selection of surgical schemes for patients with obstructive colorectal cancer. In total 89 patients with obstructive colorectal cancer treated in the Taizhou Hospital of Zhejiang Province, Wenzhou Medical University, from February 2016 to March 2017 were selected for retrospective analysis. Forty-nine cases treated with intestinal metal stent implantation combined with laparoscopic surgery and neoadjuvant chemotherapy were the stent group. The other 40 cases treated with trans-anal ileus catheter combined with laparoscopic surgery and neoadjuvant chemotherapy were the catheter group. The intestinal preparation time, surgical duration, intraoperative blood loss, open surgery rate, postoperative exhaust time and adverse reaction rate were compared between the two groups. All the patients were followed up with reexamination at 1 year in hospital to record the local recurrence rate and tumor implantation rate of incision. The intestinal preparation time in the stent group was shorter than that in the catheter group (P<0.001). The surgical duration in the stent group was longer than that in the catheter group (P<0.001). The intraoperative blood loss in the stent group was higher than that in the catheter group (P<0.001). However, there was no significant difference in open surgery rate, postoperative exhaust time, adverse reaction rate, local recurrence rate or incision tumor implantation rate between the two groups (all P>0.05). Therefore, intestinal metal stent implantation can effectively relieve intestinal obstruction, while trans-anal ileus catheter has higher safety in laparoscopic surgery. Their combination with neoadjuvant chemotherapy and laparoscopic surgery for obstructive colorectal cancer has high value and clinical effect. The best treatment plan should be selected according to the patient's condition.

Targeting CDK7 increases the stability of Snail to promote the dissemination of colorectal cancer

Targeted inhibition of cyclin-dependent kinase 7 (CDK7) via its covalent inhibitor THZ1 can suppress the growth of various cancers, while its roles on colorectal cancer (CRC) remain obscure. Here we report that the expression of CDK7 is upregulated in CRC cells and tissues. THZ1 exhibits high potency and selectivity against CRC cells both in vitro and in vivo via induction of cell apoptosis rather than cell cycle disruption. Intriguingly, THZ1 treatment increases the ability of epithelial mesenchymal transition (EMT) and in vivo metastasis to liver of CRC cells. Mechanistical studies reveal that THZ1 increases the expression of Snail, while not other EMT-transcription factors, via enhancing its protein stability rather than mRNA expression or translation. By screening Snail stability related factors via qRT-PCR, results indicate THZ1 and si-CDK7 decrease the expression of protein kinase D1 (PKD1) in CRC cells. Down regulation of PKD1 mediates THZ1 up regulated Snail via dephosphorylation of Snail Ser 11 and prevention of proteasome mediated degradation. Clinical analysis confirms that CDK7 is significantly (p < 0.05) negatively correlated with the expression of mesenchymal markers including FN1, VIM, and MMP2. CRC patients whose tumors expressing less CDK7/SNAI1 or PKD1/SNAI1 showed significant (p < 0.05) poorer overall survival (OS) rate as compared with those with greater levels. Collectively, our data suggest that targeted inhibition of CDK7 can trigger the metastasis of CRC during cancer development via PKD1/Snail axis, which imposes great challenge that inhibition of CDK7 is a potential approach for cancer treatment.

Prognostic value of small nuclear RNAs (snRNAs) for digestive tract pan- adenocarcinomas identified by RNA sequencing data

Malignant tumors of the digestive tract include esophageal, gastric, and colorectal carcinomas, which all have high global mortality rates. A clinical role for small nuclear RNA (snRNA), a type of small non-coding RNA, has not yet been documented for digestive tract pan-adenocarcinomas. Therefore, the aim of the study was to identify differentially expressed snRNAs and to explore their prognostic implications in pan-adenocarcinomas from the esophagus, stomach, colon, and rectum. The pan-carcinoma RNA-sequencing data of four types of digestive tract cancers with 1, 102 cases obtained from The Cancer Genome Atlas (TCGA) project were analyzed and the differentially expressed snRNAs were evaluated using the edgeR package. The prognostic value of each of the selected snRNAs was determined by univariate and multivariate Cox regression analyses. All the digestive tract pan-adenocarcinomas showed differential expression of three snRNAs: the up-regulated RNU1-106 P and RNU6-850 P and the down-regulated RNU6-529 P. Interestingly, RNU6-101 P appeared to be a risk factor for esophageal adenocarcinoma (ESAD) and RNVU1-4 was potentially a protective factor for stomach adenocarcinoma (STAD) survival. This consistent finding of differential expression of all three snRNAs in all four types of digestive system cancers suggests potential roles for these snRNAs in the tumorigenesis of digestive system cancers. RNU6-101 P could play a pivotal role in the progression of ESAD and RNVU1-4 could perform a protective role in STAD. However, since the current findings were based on RNA-sequencing data mining, more studies are needed for verification.

Colorectal neoplasia differentially expressed: a long noncoding RNA with an imperative role in cancer

Colorectal neoplasia differentially expressed (CRNDE), as a long noncoding RNA (lncRNA), has attracted increasing attention in recent years and has been documented to be at abnormally high expression in various types of cancer, such as colorectal cancer, glioma, hepatocellular carcinoma, lung cancer, and breast cancer. It could not only be used as a clinical biomarker for the early diagnosis and prognosis evaluation in a variety of cancers but also promote the development and progress of various tumor cells. Moreover, it is involved in the targeting regulation of multiple microRNAs and the activation/inhibition of multiple signaling pathways. In this review, we presented a systematic summary of the potential carcinogenicity and clinical value of CRNDE in the current evidence, so as to provide reference for early diagnosis, prognosis evaluation, and targeted therapy of various clinical cancers.

Colorectal cancer and brain metastases: An aggressive disease with a different response to treatment

INTRODUCTION

Brain metastases (BM) are rare in colorectal cancer (CRC) and are associated with a dismal prognosis. This work aims to report the rate of BM in CRC patients treated in a single institution, along with survival and prognostic factors.

METHODS

Medical charts for patients with histologically proven CRC were retrospectively reviewed.

RESULTS

A total of 538 patients were identified, of whom 33% developed any metastatic disease and 4.4% presented BM. Lung was the most frequently associated metastatic site (in 68% of the cases). The only factor independently associated with BM development was the presence of metastatic disease at the time of initial presentation. The median duration from initial diagnosis to BM development was 38.6 months (SD 29.1 months). Median survival after BM development was 62 days (95% confidence interval [CI] 56-68). Patients diagnosed with BM within 1 year of cancer diagnosis responded significantly better to treatment than those who acquired BM later, with a median survival after BM diagnosis of 261 days versus 61 days, respectively (p = .002). Patients with BM who received antiangiogenic therapy had an improved median survival compared to those who did not (151 days vs 59 days, p = 0.02; hazard ratio for death 0.29 [95% CI 0.09-0.94]).

CONCLUSION

CRC with BM is an aggressive disease resistant to standard treatment and is associated with poor outcomes. Adding antiangiogenic therapy might be of value for those patients. Patients with BM developing early in the disease course might respond better to treatment.

Cancer Incidence Among Patients of the U.S. Veterans Affairs Health Care System: 2010 Update

INTRODUCTION

Nearly 50,000 incident cancer cases are reported in Veterans Affairs (VA) Central Cancer Registry (VACCR) annually. This article provides an updated report of cancer incidence recorded in VACCR.

MATERIALS AND METHODS

Data were obtained from VACCR for incident cancers diagnosed in the VA health care system, focusing on 2010 data. Cancer incidence among VA patients is described by anatomical site, sex, race, stage, and geographic location, and was compared to the general U.S. cancer population.

RESULTS

In 2010, among 46,170 invasive cancers, 97% were diagnosed among men. Approximately 80% of newly diagnosed patients were white, 19% black, and less than 2% were other minority races. Median age at diagnosis was 65 years. The three most frequently diagnosed cancers among VA were prostate (29%), lung/bronchus (18%), and colon/rectum (8%). Melanoma and kidney/renal pelvis tied for fourth (4%), and urinary bladder tied for sixth with liver and intrahepatic bile duct (3.4%). Approximately 23% of prostate, 21% of lung/bronchus, and 31% of colon/rectum cancers were diagnosed with Stage I disease. The overall invasive cancer incidence rate among VA users was 505.8 per 100,000 person-years.

CONCLUSIONS

Although the composition of the VA population is shifting and includes a larger number of women, registry data indicate that incident cancers in VA in 2010 were most similar to those observed among U.S. men. Consistent reporting of VACCR data is important to provide accurate estimates of VA cancer incidence. This information can be used to plan efforts to improve quality of cancer care and access to services.

Meta-signature LncRNAs serve as novel biomarkers for colorectal cancer: integrated bioinformatics analysis, experimental validation and diagnostic evaluation

The aim of this study is to explore the differentially expressed lncRNAs, which may have potential biological function and diagnostic value in colorectal cancer (CRC). Through integrated data mining, we finally identified nine differentially expressed lncRNAs and their potential mRNA targets. After a series of bioinformatics analyses, we screened significant pathways and GO terms that are related to the up-regulated and down-regulated transcripts respectively. Meanwhile, the nine lncRNAs were validated in 30 paired tissues and cell lines by qRT-PCR and the results were basically consistent with the microarray data. We also tested the nine lncRNAs in the serum of 30 CRC patients matched with the CRC tissue, 30 non-cancer patients and 30 health controls. Finally, we found that BLACAT1 was significant for the diagnosis of CRC. The area under the curve (AUC), sensitivity and specificity were 0.858 (95% CI: 0.765-0.951), 83.3% and 76.7% respectively between CRC patients and health controls. Moreover, BLACAT1 also had distinct value to discriminate CRC from other non-cancer diseases. The results indicated that the differentially expressed lncRNAs and their potential target transcripts could be considered as potential therapeutic targets for CRC patients. Meanwhile, lncRNA BLACAT1 might represent a new supplementary biomarker for the diagnosis of CRC.

Long Non-Coding RNA Reprogramming (ROR) Promotes Cell Proliferation in Colorectal Cancer via Affecting P53

BACKGROUND Colorectal cancer (CRC) remains one of the most common lethal malignant tumors worldwide. The correlation between lncRNAs expression and CRC development has not been well identified in the recent literature. This study focused on the role of lncRNA-ROR on CRC progression and development. MATERIAL AND METHODS Quantitative real-time PCR (qRT-PCR) assay was conducted to identify the expression level of lncRNA-ROR. Cell proliferation and viability were examined by MTT assay and colony formation assay. Cell cycle distribution and apoptosis were detected by flow cytometry. Expressions of p53, p21, and FAS protein levels were assessed by Western blotting. CRC cells transfected with lncRNA-shRNA were injection into nude mice to identify the function of lncRNA-ROR on tumorigenesis in vivo. RESULTS The expression level of lncRNA-ROR was elevated in CRC tissues when compared to adjacent tissues (n=78). lncRNA-ROR knockdown significantly suppressed cell proliferation and viability, while lncRNA-ROR overexpression had the opposite effect. Decreased lncRNA-ROR expression enhanced cell apoptosis and triggered cell cycle arrest in G0/G1 phase, while elevated lncRNA-ROR expression presented the opposite effect. Protein levels of p53 and p53 target genes were affected by lncRNA-ROR in vitro, and downregulation of lncRNA-ROR impeded tumorigenesis in vivo. CONCLUSIONS Our study demonstrates that lncRNA-ROR participates in controlling CRC proliferation, viability, and apoptosis, partially by modulating p53, which provides potential and prospective therapeutic targets for CRC.