Evidence-based Guidelines for Precision Risk Stratification-Based Screening (PRSBS) for Colorectal Cancer: Lessons learned from the US Armed Forces: Consensus and Future Directions

SERS-based methods for the detection of genomic biomarkers of cancer

Genomic biomarkers of cancer are based on changes in nucleic acids, which include abnormal expression levels of some miRNAs, point mutations in DNA sequences, and altered levels of DNA methylation. The presence of tumor-related nucleic acids in body fluids (blood, saliva, or urine) makes it possible to achieve a non-invasive early-stage cancer diagnosis. Currently existing techniques for the discovery of nucleic acids require complex, time-consuming, costly assays and have limited multiplexing abilities. Surface-enhanced Raman spectroscopy (SERS) is a vibrational spectroscopy technique that is able to provide molecular specificity combined with trace sensitivity. SERS has gained research attention as a tool for the detection of nucleic acids because of its promising potential: label-free SERS can decrease the complexity of assays currently used with fluorescence-based detection due to the absence of the label, while labeled SERS may outperform the gold standard in terms of the multiplexing ability. The first papers about SERS-based methods for the measurement of genomic biomarkers were written in 2008, and since then, more than 150 papers have been published. The aim of this paper is to review and evaluate the proposed SERS-based methods in terms of their level of development and their potential for liquid biopsy application, as well as to contribute to their further evolution by attracting research attention to the field. This goal will be reached by grouping, on the basis of their experimental protocol, all the published manuscripts on the topic and evaluating each group in terms of its limit of detection and applicability to real body fluids. Thus, the methods are classified according to their working principles into five main groups, including capture-based, displacement-based, sandwich-based, enzyme-assisted, and specialized protocols.

A scoping review of risk-stratified bowel screening: current evidence, future directions

PURPOSE

In this scoping review, we examined the international literature on risk-stratified bowel screening to develop recommendations for future research, practice and policy.

METHODS

Six electronic databases were searched from inception to 18 October 2021: Medline, Embase, PsycINFO, CINAHL, Cochrane Database of Systematic Reviews and Cochrane Central Register of Controlled Trials. Forward and backwards citation searches were also undertaken. All relevant literature were included.

RESULTS

After de-deduplication, 3,629 records remained. 3,416 were excluded at the title/abstract screening stage. A further 111 were excluded at full-text screening stage. In total, 102 unique studies were included. Results showed that risk-stratified bowel screening programmes can potentially improve diagnostic performance, but there is a lack of information on longer-term outcomes. Risk models do appear to show promise in refining existing risk stratification guidelines but most were not externally validated and less than half achieved good discriminatory power. Risk assessment tools in primary care have the potential for high levels of acceptability and uptake, and therefore, could form an important component of future risk-stratified bowel screening programmes, but sometimes the screening recommendations were not adhered to by the patient or healthcare provider. The review identified important knowledge gaps, most notably in the area of organisation of screening services due to few pilots, and what risk stratification might mean for inequalities.

CONCLUSION

We recommend that future research focuses on what organisational challenges risk-stratified bowel screening may face and a consideration of inequalities in any changes to organised bowel screening programmes.

Cancer prevention and screening: the next step in the era of precision medicine

A primary mode of cancer prevention and early detection in the United States is the widespread practice of screening. Although many strategies for early detection and prevention are available, adverse outcomes, such as overdiagnosis and overtreatment, are prevalent among those utilizing these approaches. Broad use of mammography and prostate cancer screening are key examples illustrating the potential harms stemming from the detection of indolent lesions and the subsequent overtreatment. Furthermore, there are several cancers for which prevention strategies do not currently exist. Clinical and experimental evidence have expanded our understanding of cancer initiation and progression, and have instructed the development of improved, precise modes of cancer prevention and early detection. Recent cancer prevention and early detection innovations have begun moving towards the integration of molecular knowledge and risk stratification profiles to allow for a more accurate representation of at-risk individuals. The future of cancer prevention and early detection efforts should emphasize the incorporation of precision cancer prevention integration where screening and cancer prevention regimens can be matched to one's risk of cancer due to known genomic and environmental factors.

Primary care providers' cancer genetic testing-related knowledge, attitudes, and communication behaviors: A systematic review and research agenda

BACKGROUND

Primary care providers (PCPs) can play a critical role in helping patients receive the preventive health benefits of cancer genetic risk information. Thus, the objective of this systematic review was to identify studies of US PCPs' knowledge, attitudes, and communication-related behaviors regarding genetic tests that could inform risk-stratification approaches for breast, colorectal, and prostate cancer screening in order to describe current findings and research gaps.

METHODS

We conducted a systematic search of six electronic databases to identify peer-reviewed empirical articles relating to US PCPs and genetic testing for breast, colorectal, or prostate cancer published in English from 2008 to 2016. We reviewed these data and used narrative synthesis methods to integrate findings into a descriptive summary and identify research needs.

RESULTS

We identified 27 relevant articles. Most focused on genetic testing for breast cancer (23/27) and colorectal cancer risk (12/27); only one study examined testing for prostate cancer risk. Most articles addressed descriptive research questions (24/27). Many studies (24/27) documented PCPs' knowledge, often concluding that providers' knowledge was incomplete. Studies commonly (11/27) examined PCPs' attitudes. Across studies, PCPs expressed some concerns about ethical, legal, and social implications of testing. Attitudes about the utility of clinical genetic testing, including for targeted cancer screening, were generally favorable; PCPs were more skeptical of direct-to-consumer testing. Relatively fewer studies (9/27) examined PCPs' communication practices regarding cancer genetic testing.

DISCUSSION

This review indicates a need for investigators to move beyond descriptive research questions related to PCPs' knowledge and attitudes about cancer genetic testing. Research is needed to address important gaps regarding the development, testing, and implementation of innovative interventions and educational programs that can improve PCPs' genetic testing knowledge, assuage concerns about the appropriateness of cancer genetic testing, and promote open and effective patient-provider communication about genetic risk and genetic testing.

Driver Gene Mutations in Stools of Colorectal Carcinoma Patients Detected by Targeted Next-Generation Sequencing

Detection of driver gene mutations in stool DNA represents a promising noninvasive approach for screening colorectal cancer (CRC). Amplicon-based next-generation sequencing (NGS) is a good option to study mutations in many cancer genes simultaneously and from a low amount of DNA. Our aim was to assess the feasibility of identifying mutations in 22 cancer driver genes with Ion Torrent technology in stool DNA from a series of 65 CRC patients. The assay was successful in 80% of stool DNA samples. NGS results showed 83 mutations in cancer driver genes, 29 hotspot and 54 novel mutations. One to five genes were mutated in 75% of cases. TP53, KRAS, FBXW7, and SMAD4 were the top mutated genes, consistent with previous studies. Of samples with mutations, 54% presented concomitant mutations in different genes. Phosphatidylinositol 3-kinase/mitogen-activated protein kinase pathway genes were mutated in 70% of samples, with 58% having alterations in KRAS, NRAS, or BRAF. Because mutations in these genes can compromise the efficacy of epidermal growth factor receptor blockade in CRC patients, identifying mutations that confer resistance to some targeted treatments may be useful to guide therapeutic decisions. In conclusion, the data presented herein show that NGS procedures on stool DNA represent a promising tool to detect genetic mutations that could be used in the future for diagnosis, monitoring, or treating CRC.

2-(Pro-1-ynyl)-5-(5,6-dihydroxypenta-1,3-diynyl) thiophene induces apoptosis through reactive oxygen species-mediated JNK activation in human colon cancer SW620 cells

2-(Pro-1-ynyl)-5-(5,6-dihydroxypenta-1,3-diynyl) thiophene (PYDDT) is a naturally occurring thiophene isolated from the roots of Echinops grijsii, a Chinese herbal medicine used to treat colon cancer, breast cancer, and lung cancer. There are many reports on the clinical use of Echinops grijsii alone or in combination with other herbs to treat malignant tumors. We previously reported that the expression and activity of phase II enzymes including GSTs and NQO1 could be induced through the activation of Keap1-Nrf2 pathway by the treatment of PYDDT. In this study, we reported the anticancer effect and mechanism of PYDDT against human colon cancer SW620 cells. Our results demonstrate that treatment of SW620 cells with PYDDT leads to induction of mitochondrial-mediated apoptosis, which is characterized by the cleavage of PARP, activation of caspase 9 and caspase 3, release of cytochrome c from mitochondria, loss of mitochondrial membrane potential, down-regulation of Bcl-2, and mitochondrial translocation of Bax. The PYDDT treatment caused the production of reactive oxygen species (ROS), and the activation of JNK but not p38 mitogen-activated protein kinases and ERK1/2. Specific JNK inhibitor SP600125 prevented the PYDDT-induced down-regulation of Bcl-2, mitochondrial translocation of Bax, activation of caspase 3, and apoptosis of SW620 cells. Moreover, PYDDT-induced apoptosis as well as activation of JNK was abrogated by the pretreatment with antioxidant N-acetylcysteine. Taken together, these findings suggest that PYDDT induces apoptosis in SW620 cells through a ROS/JNK-mediated mitochondrial pathway.

Future directions for the early detection of colorectal cancer recurrence

Surgical resection remains a mainstay of treatment and is highly effective for localized colorectal cancer. However, ~30-40% of patients develop recurrence following surgery and 40-50% of recurrences are apparent within the first few years after initial surgical resection. Several variables factor into the ultimate outcome of these patients, including the extent of disease, tumor biology, and patient co-morbidities. Additionally, the time from initial treatment to the development of recurrence is strongly associated with overall survival, particularly in patients who recur within one year of their surgical resection. Current post-resection surveillance strategies involve physical examination, laboratory, endoscopic and imaging studies utilizing various high and low-intensity protocols. Ultimately, the goal is to detect recurrence as early as possible, and ideally in the asymptomatic localized phase, to allow initiation of treatment that may still result in cure. While current strategies have been effective, several efforts are evolving to improve our ability to identify recurrent disease at its earliest phase. Our aim with this article is to briefly review the options available and, more importantly, examine emerging and future options to assist in the early detection of colon and rectal cancer recurrence.

The promise of using personalized genomic information to promote behavior change: is the debate over, or just beginning?

Over recent years, significant debate has centered on whether and how communication of personalized genomic risk information can positively influence health behavior change. Several thoughtful commentaries have cautioned that efforts to incorporate genomic risk feedback to motivate health behavior change have had little success. As a field, we should consider the reasons for this limited success and be strategic in the next steps for this line of research. In this article, we consider several reasons that prior research that integrates personalized genomic information has had relative degrees of success in changing or maintaining health behaviors. We suggest ways forward and outline the possibilities presented by emerging technologies and novel approaches in translational genomic research.

Prevalence of colorectal neoplasia among young African Americans and Hispanic Americans

BACKGROUND

The disproportionately higher incidence of and mortality from colorectal cancer (CRC) among African Americans (AA) led the American College of Gastroenterology to recommend screening starting at age 45 in 2005.

AIM

The purpose of this study was to determine the prevalence of colorectal neoplasia among 40-49-year-old inner city AA and Hispanic Americans (HA).

METHODS

We reviewed the medical records of 2,435 inner city AA and HA who underwent colonoscopy regardless of indication and compared the prevalence of colorectal neoplasia between AA and HA patients. We used logistic regression models to calculate odds ratios (OR) and 95 % confidence intervals (CI).

RESULTS

There were 2,163 AAs and 272 HA. There were 57 % women in both groups. A total of 158 (7 %) AA and 9 (3 %) HA (P = 0.014) underwent the procedures for CRC screening. When compared to HAs, AAs had higher prevalence of any polyp (35 vs. 18 %, OR = 2.53; 95 % CI 1.82-3.52). Overall, AA had higher prevalence of colorectal neoplasia (adenoma and cancer) when compared to HAs (16 vs. 10 %; OR = 1.68; 95 % CI 1.10-2.56).

CONCLUSION

We observed a higher frequency of colorectal neoplasia among 40-49-year-old AAs as compared to HAs suggesting an increased susceptibility to CRC risk in this population.