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

A Systems Biology Approach to Understand the Racial Disparities in Colorectal Cancer

Racial disparities between Black/African Americans (AA) and White patients in colorectal cancer are an ever-growing area of concern. Black/AA show the highest incidence and have the highest mortality among major U.S. racial groups. There is no definite cause other than possible sociodemographic, socioeconomic, education, nutrition, delivery of healthcare, screening, and cultural factors. A primary limitation in this field is the lack of and small sample size of Black/AA studies. Thus, this study aimed to investigate whether differences in gene expression contribute to this ongoing unanswered racial disparity issue. In this study, we examined transcriptomic data of Black/AA and White patient cohorts using a bioinformatic and systems biology approach. We performed a Kaplan-Meier overall survival analysis between both patient cohorts across critical colorectal cancer signal transduction networks (STN), to determine the differences in significant genes across each cohort. Other bioinformatic analyses performed included PROGENy (pathway responsive genes for activity inference), RNA sequencing differential expression using DESeq2, multivariable-adjusted regression, and other associated Kaplan-Meier analyses. These analyses identified novel prognostic genes independent from each cohort, 176 differentially expressed genes, and specific patient cohort STN survival associations. Despite the overarching limitation, the results revealed several novel differences in gene expression between the colorectal cancer Black/AA and White patient cohorts, which allows one to dive deeper into and understand the behavior on a systems level of what could be driving this racial difference across colorectal cancer. Concretely, this information can guide precision medicine approaches tailored specifically for colorectal cancer racial disparities.

SIGNIFICANCE

The purpose of this work is to investigate the racial disparities in colorectal cancer between Black/AA and White patient cohorts using a systems biology and bioinformatic approach. Our study investigates the underlying biology of each patient cohort. Concretely, the findings of this study include disparity-associated genes and pathways, which provide a tangible starting point to guide precision medicine approaches tailored specifically for colorectal cancer racial disparities.

Adenoma location, size, and morphology are risk factors for FOBT false-negative results in inpatients with advanced colorectal adenoma

Recently, advanced adenoma (AA) has been recognized as a target for colorectal cancer (CRC) screening. However, the fecal occult blood test (FOBT), the primary non-invasive screening method, shows limited sensitivity in detecting AA. This study investigates the relationship between adenoma characteristics and FOBT false-negative results. In a retrospective cohort study conducted from 2015 to 2022, we examined 342 inpatients with AA who underwent colonoscopy and received qualitative FOBT. FOBT sensitivity was analyzed about various adenoma characteristics, and logistic regression models were employed to investigate the relationship between adenoma features and FOBT false-negative outcomes. FOBT sensitivity in AA inpatients was 52.63%. Significant differences in sensitivity were observed based on adenoma location (left vs. right), morphology (with or without pedunculation), and size (≤ 10 mm vs. > 10 mm). After adjusting for several potential confounders, FOBT showed a reduced false-negative rate in AA with large-sized (OR, 0.49; 95% CI 0.31-0.77), left-sided location (OR, 0.53; 95% CI 0.31-0.89), and pedunculated morphology (OR, 0.73; 95% CI 0.43-1.24). AA with large size, left-sided location, and pedunculated morphology independently contribute to a decreased rate of FOBT false-negative results. However, these adenoma characteristics are not actively modifiable. Therefore, novel non-invasive methods are needed to improve AA detection accuracy.

Application and development of noninvasive biomarkers for colorectal cancer screening: a systematic review

BACKGROUND

Colorectal cancer (CRC) is the second most common cause of cancer-related death (9.4% of the 9.9 million cancer deaths). However, CRC develops slowly, and early detection and intervention can effectively improve the survival rate and quality of life. Although colonoscopy can detect and diagnose CRC, it is unsuitable for CRC screening in average-risk populations. Some commercial kits based on DNA mutation or methylation are approved for screening, but the low sensitivity for advanced adenoma or early-stage CRC would limit the applications.

MAIN RESULTS

Recently, researchers have focused on developing noninvasive or minimally invasive, easily accessible biomarkers with higher sensitivity and accuracy for CRC screening. Numerous reports describe advances in biomarkers, including DNA mutations and methylation, mRNA and miRNA, gut microbes, and metabolites, as well as low-throughput multiomics panels. In small cohorts, the specificity and sensitivity improved when fecal immunochemical testing combined with other biomarkers; further verification in large cohorts is expected. In addition, the continuous improvement of laboratory technology has also improved the sensitivity of detection technology, such as PCR, and the application of CRISPR/Cas technology. Besides, artificial intelligence has extensively promoted the mining of biomarkers. Machine learning was performed to construct a diagnosis model for CRC screening based on the cfDNA fragment features from whole-genome sequencing data. In another study, multiomics markers, including cfDNA, epigenetic, and protein signals, were also discovered by machine learning. Finally, advancements in sensor technology promote the applicability of volatile organic compounds in CRC early detection.

CONCLUSION

Here, the authors review advances in early detection and screening of CRC based on different biomarker types. Most studies reported optimistic findings based on preliminary research, and prospective clinical studies are ongoing. These promising biomarkers are expected to more accurately identify early-stage patients with CRC and be applied in the future.

YYFZBJS inhibits colorectal tumorigenesis by enhancing Tregs-induced immunosuppression through HIF-1α mediated hypoxia in vivo and in vitro

BACKGROUND AND PURPOSE

The occurrence of colorectal cancer (CRC) is associated with a variety of factors. Accumulating evidence shows that peripheral differentiation of regulatory T cells (Tregs) is critical in controlling tumorigenesis. Our previous studies demonstrated that the Yi-Yi-Fu-Zi-Bai-Jiang-San (YYFZBJS) extract exerted potent anticancer activities by significantly enhancing immunosuppression in ApcMin/+ mice. However, there is limited knowledge on the effect of YYFZBJS in the prevention of colorectal cancer and the underlying mechanisms of action.

METHODS

In this study, we investigated the effect of oral administration of YYFZBJS in preventing azoxymethane (AOM)/dextran sulfate sodium (DSS)-induced tumorigenesis. We found that YYFZBJS treatment decreased tumor load, tumor number, histology, and the severity of disease activity index (DAI) scores. To investigate if YYFZBJS inhibited tumorigenesis by regulating regulatory T cells, we depleted Tregs in AOM/DSS mice. We then analyzed the effect of intragastric administration of YYFZBJS on tumorigenesis and the regulation of tumor microenvironment.

RESULTS

As expected, intragastric administration of YYFZBJS in AOM/DSS mice model significantly increased immune responses in the tumor microenvironment through its hypoxia-associated anti-cancer activities. Additionally, YYFZBJS regulated the polarization of peripheral Treg (pTreg) to suppress CRC cell proliferation and infiltration. This was demonstrated by the decrease in tumor proliferation-related proteins including p-STAT3, p-NF-κB and MMPs in a dose-dependent manner. Clinically, the increase in the levels of Tregs in human tissues during CRC progression was associated with low expression of HIF-1α in the stroma, and correlated with CRC survival and prognosis.

CONCLUSION

Altogether, we demonstrated that HIF-1α may promote pTreg -induced carcinogenesis and progression of CRC cells, indicating that YYFZBJS is a promising protective agent against HIF-1α-mediated Treg activation in colorectal cancer. This study is the first to imply a novel clinical significance of a traditional Chinese herbal medicine from Synopsis of Golden Chamber in the cancer treatment and clarify the important role of tumor microenvironment in preventing tumorigenesis.