Racial/Ethnic and Sex Differences in Somatic Cancer Gene Mutations among Patients with Early-Onset Colorectal Cancer

Recent advances in the role of atypical cadherin FAT1 in tumorigenesis (Review)

The FAT atypical cadherin 1 (FAT1) gene is the ortholog of the Drosophila fat gene and encodes the protocadherin FAT1. FAT1 belongs to the cadherin superfamily, a group of full-length membrane proteins that contain cadherin-like repeats. In various types of human cancer, FAT1 is one of the most commonly mutated genes, and is considered to be an emerging cancer biomarker and a potential target for novel therapies. However, the biological functions of FAT1 and the precise downstream signaling pathways that it mediates have remained to be fully elucidated. The present review discussed the current literature on FAT1, focusing on FAT1 mutations and expression levels, and their impact on signaling pathways and mechanisms in various types of cancer, including both solid tumors and hematological malignancies, such as esophageal squamous cell carcinoma, head and neck squamous cell carcinoma, lung squamous cell carcinoma, hepatocellular carcinoma, glioma, breast cancer, acute lymphoblastic leukemia, acute myeloid leukemia, lymphoma and myeloma. The present review aimed to provide further insights and research directions for future studies on FAT1 as an oncogenic factor or tumor suppressor.

DNA methylation profiling at base-pair resolution reveals unique epigenetic features of early-onset colorectal cancer in underrepresented populations

BACKGROUND

The incidence of early-onset colorectal cancer (EOCRC) has been rising at an alarming rate in the USA, and EOCRC disproportionately affects racial/ethnic minorities. Here, we construct comprehensive profiles of EOCRC DNA methylomes at base-pair resolution for a cohort of Hispanic and African American patients.

RESULTS

We show the epigenetic landscape of these EOCRC patients differs from that of late-onset colorectal cancer patients, and methylation canyons in EOCRC tumor tissue preferentially overlapped genes in cancer-related pathways. Furthermore, we identify epigenetic alterations in metabolic genes that are specific to our racial/ethnic minority EOCRC cohort but not Caucasian patients from TCGA. Top genes differentially methylated between these cohorts included the obesity-protective MFAP2 gene as well as cancer risk susceptibility genes APOL3 and RNASEL.

CONCLUSIONS

In this study, we provide to the scientific community high-resolution DNA methylomes for a cohort of EOCRC patients from underrepresented populations. Our exploratory findings in this cohort highlight epigenetic mechanisms underlying the pathogenesis of EOCRC and nominate novel biomarkers for EOCRC in underrepresented populations.

Evolving landscape of colorectal cancer: Global and regional burden, risk factor dynamics, and future scenarios (the Global Burden of Disease 1990-2050)

BACKGROUND

Presently, colorectal cancer (CRC) is the second leading cause of cancer-related deaths worldwide. We provided global, regional, and national estimates of the burden of CRC and their attributable risks from 1990 to 2021, aiming to guide screening, early detection, and treatment strategies, optimize healthcare resource allocation, and facilitate the rational management of burden of CRC.

METHODS

Using data derived from the Global Burden of Disease database, we estimated the incidence, mortality, and disability-adjusted life years (DALYs) of CRC. The temporal trends of the age-standardized rate of CRC were quantified by calculating the estimated annual percentage changes (EAPC). Deaths from CRC attributable to each risk factor that had evidence of causation with CRC were estimated. CRC's deaths and DALYs was forecast through 2050 by logistic regression with Socio-Demographic Index as a predictor, then multiplying by projected population estimates.

RESULTS

Globally, between 1990 and 2021, the incident cases, death cases, and DALYs attributed to CRC have doubled, the age-standardized incidence rate (ASIR) presented a slightly upward tendency, while the age-standardized death rate (ASMR) and the age-standardized DALYs rate (ASDR) exhibited a decreasing trend. From 1990-2021, the ASIR for males has an increased trend, while females presented a downward trend. The ASIR and ASDR of CRC were higher in high and high-middle sociodemographic index (SDI) countries. The ASIR of CRC in 165 countries and territories showed escalating trend. Globally, for males and both sexes combined, diet low in whole grains was the leading risk factor for age-standardized deaths from CRC in 2021. However, among females, diet low in milk was the leading risk factor. We forecast that 2.18 million (1.53-2.94) individuals will death for CRC worldwide by 2050, and the DALYs achieve 41.7 million (29.9-55.4) by 2050.

CONCLUSION

The doubling of incidence counts and mortality cases and the rising ASIR in most countries indicates a significant burden of CRC. Authorities should devise suitable measures to address the increasing burdens, such as optimizing screening programs, enhancing awareness and screening efforts for males, and reducing exposure to modifiable risk factors.

Mutational and co-mutational landscape of early onset colorectal cancer

INTRODUCTION

Colorectal cancer (CRC) incidence and mortality before 50 have been rising alarmingly in the recent decades.

METHODS

Using a cohort of 10,000 patients, this study investigates the clinical, mutational, and co-mutational features of CRC in early-onset (EOCRC, < 50 years) compared to late-onset (LOCRC, ≥ 50 years).

RESULTS

EOCRC was associated with a higher prevalence of Asian and Hispanic patients, rectal or left-sided tumors (72% vs. 59%), and advanced-stage disease. Molecular analyses revealed differences in mutation patterns, with EOCRC having higher frequencies of TP53 (74% vs. 68%, p < 0.01) and SMAD4 (17% vs. 14%, p = 0.015), while BRAF (5% vs. 11%, p < 0.001) and NOTCH1 (2.7% vs. 4.1%, p = 0.01) mutations were more prevalent in LOCRC. Stratification by tumor site and MSI status highlighted significant location- and age-specific molecular differences, such as increased KRAS and CTNNB1 mutations in right-sided EOCRC and higher BRAF prevalence in MSI-H LOCRC (47% vs. 6.7%, p < 0.001). Additionally, co-occurrence analysis revealed unique mutational networks in EOCRC MSS, including significant co-occurrences of FBXW7 with NOTCH3, RB1, and PIK3R1.

CONCLUSION

This study highlights the significance of age-specific molecular profiling, offering insights into the unique biology of EOCRC and potential clinical applications.

OncoSexome: the landscape of sex-based differences in oncologic diseases

The NIH policy on sex as biological variable (SABV) emphasized the importance of sex-based differences in precision oncology. Over 50% of clinically actionable oncology genes are sex-biased, indicating differences in drug efficacy. Research has identified sex differences in non-reproductive cancers, highlighting the need for comprehensive sex-based cancer data. We therefore developed OncoSexome, a multidimensional knowledge base describing sex-based differences in cancer (https://idrblab.org/OncoSexome/) across four key topics: antineoplastic drugs and responses (SDR), oncology-related biomarkers (SBM), risk factors (SRF) and microbial landscape (SML). SDR covers sex-based differences in 2051 anticancer drugs; SBM describes 12 551 sex-differential biomarkers; SRF illustrates 350 sex-dependent risk factors; SML demonstrates 1386 microbes with sex-differential abundances associated with cancer development. OncoSexome is unique in illuminating multifaceted influences of biological sex on cancer, providing both external and endogenous contributors to cancer development and describing sex-based differences for the broadest oncological classes. Given the increasing global research interest in sex-based differences, OncoSexome is expected to impact future precision oncology practices significantly.

Nomogram based on the log odds of negative lymph node/T stage can predict the prognosis of patients with colorectal cancer: a retrospective study based on SEER database and external validation in China

OBJECTIVES

This study investigated the prognostic role of log odds of negative lymph node/T stage (LONT) and established a nomogram based on LONT to predict the prognosis in colorectal cancer (CRC) patients.

DESIGN

A retrospective cohort study.

SETTING AND PARTICIPANTS

We enrolled 80 518 CRC patients from the Surveillance, Epidemiology and End Results database between 2010 and 2015. The dataset was split into a training cohort (56 364 patients) and a validation cohort (24 154 patients) at a ratio of 7:3. Furthermore, 500 CRC patients who underwent surgery in the Tenth Affiliated Hospital of Southern Medical University between 1 January 2017 and 20 December 2018, were recruited as the external validation set.

OUTCOME MEASURES

1-, 3- and 5-year cancer-specific survival (CSS).

METHODS

The univariate and multivariate Cox regression analyses were carried out to identify the significant independent prognostic factors of CSS. A nomogram was established based on LONT to predict the prognosis. The performance of the nomogram was comprehensively assessed via the time-dependent receiver operating characteristic curve, concordance index (C-index), calibration curve and decision curve analysis (DCA) comprehensively. Moreover, Kaplan-Meier curves were performed to assess the CSS of the three risk subgroups.

RESULT

LONT was a significant independent prognostic factor for CSS (LONT1 vs LONT2, HR=0.670, 95% CI 0.642 to 0.698, p<0.001; LONT1 vs LONT3, HR=0.443, 95% CI 0.420 to 0.467, p<0.001). LONT, age, sex, race, subsite, differentiation, histology, tumour size, T stage, N stage, M stage and chemotherapy were included in the nomogram. The 1-, 3- and 5-year survival area under the curve were 0.856, 0.862 and 0.852, respectively. The C-index of the model was 0.809 (95% CI 0.825 to 0.839) in the model. The calibration curve and DCA verified the favourable predictive performance and clinical application of the nomogram.

CONCLUSION

CRC patients with a high LONT had a low incidence of CSS. The nomogram based on LONT could effectively predict the CSS of CRC.

A modeling of complex trait phenotypic variance determinants

Studies have now shown that the heritability of some complex traits, such as human height, can be virtually fully captured via potential use of sufficiently powered approaches that can characterize the associated collective common- and rare-variant additive genetic architecture. However, for other traits, including complex disease traits, full recovery of such narrow sense heritability would still likely fall far short of respective heritability estimates yielded from pedigree-based analyses such as twin studies. Here, it is proposed that such traits could also involve additional types of relevant architecture and underlying genetic mechanism, such that interaction of somatic variants with heritable variants may represent an underappreciated component. The theoretical model suggested predicts that some relevant heritability estimates are systematically inflated by twin studies, and that instead a significant proportion of the phenotypic variances may be explained by specialized types of heritable genotype-by-environment interaction.

Somatic mutational landscape reveals mutational signatures and significantly mutated genes of cancer immunotherapeutic outcome and sex disparities

Background

Currently developed molecular markers can predict the effectiveness of cancer immunotherapy and screen beneficiaries to some extent, but they are not stable enough. Therefore, there is an urgent need for discovering novel biomarkers. At the same time, sex factor plays a vital role in the response to immunotherapy, so it is particularly important to identify sex-related molecular indicators.

Methods

We integrated a pan-cancer cohort consisting of 2348 cancer patients who received immune checkpoint inhibitors and targeted sequencing. Using somatic mutation profiles, we identified mutational signatures, molecular subtypes, and frequently mutated genes, and analyzed their relationships with immunotherapeutic outcomes. We also explored sex disparities of determined biomarkers in response to treatments.

Results

We found that male patients exhibited better immunotherapy outcomes and higher tumor mutational burden. A total of seven mutational signatures were identified, among which signatures 1 and 3 were associated with worse immunotherapy outcomes, while signatures 2 and 6 correlated with better outcomes. Gender-based analysis revealed that mutational signature 1 continued to show a worse immunotherapy outcome in female patients, whereas signature 6 demonstrated a better outcome in male patients. Based on mutational activities, we identified four potential molecular subtypes with gender differences and relevance to treatment outcomes. PI3K-AKT, RAS signaling pathways, and 68 significantly mutated genes were identified to be associated with immunotherapy outcomes, with nine genes (i.e., ATM, ATRX, DOT1L, EP300, EPHB1, NOTCH1, PBRM1, RBM10, and SETD2) exhibiting gender differences. Finally, we discovered co-mutated gene pairs and TP53 p.R282W mutations related to treatment outcomes, highlighting their gender-specific differences.

Conclusion

This study identified several molecular biomarkers related to cancer immunotherapy outcomes in terms of mutational signatures, molecular subtypes, and mutated genes, and explored their gender-relatedness in order to provide clues and basis for clinical treatment efficacy evaluation and patient selection.

Early-Onset colorectal Cancer: From the laboratory to the clinic

Colorectal cancer that occurs before age of 50 is defined as Early-Onset Colorectal Cancer (EOCRC). Its incidence has worryingly increased since the late 90 s and is expected to keep rising in the next future, despite Late-Onset CRC (LOCRC) is decreasing worldwide. Because of this, there is an urgent need to better understand this subset of patients in order to give them the best treatment possible. However, most of the literature is retrospective and often discordant. In this review, we aim to provide a general overview of the issue, endeavoring to highlight the current available knowledge. We decided to move from the beginning, investigating risk factors and inheritance, passing through diagnosis and clinical aspects, and to conclude with the translational part, focusing on the biology of the tumor. However, lot of questions remain open, including screening age and prognosis. Indeed, young patients tend to be treated more aggressively, even if a survival benefit has not been proven yet. Every clinician should be aware of the best practice for young people, and more translational studies are awaited in order to clarify is EOCRC represents a distinct biological entity.

Early-onset cancers: Biological bases and clinical implications

Since the nineties, the incidence of sporadic early-onset (EO) cancers has been rising worldwide. The underlying reasons are still unknown. However, identifying them is vital for advancing both prevention and intervention. Here, we exploit available knowledge derived from clinical observations to formulate testable hypotheses aimed at defining the causal factors of this epidemic and discuss how to experimentally test them. We explore the potential impact of exposome changes from the millennials to contemporary young generations, considering both environmental exposures and enhanced susceptibilities to EO-cancer development. We emphasize how establishing the time required for an EO cancer to develop is relevant to defining future screening strategies. Finally, we discuss the importance of integrating multi-dimensional data from international collaborations to generate comprehensive knowledge and translate these findings back into clinical practice.

Molecular Differences With Therapeutic Implications in Early-Onset Compared With Average-Onset Biliary Tract Cancers

PURPOSE

Early-onset biliary tract cancer (eoBTC) is among the fast-growing subset of early-onset cancers, yet little is known about its biology. We sought to identify novel molecular characteristics of eoBTC in relation to average-onset BTC (aoBTC) using a real-world multiomics data set.

METHODS

The study comprised patients with BTC whose tumors underwent molecular analyses at Caris Life Sciences and were categorized by age (<50 years for eoBTC, ≥50 years for aoBTC). P values were adjusted for multiple testing and considered significant at Q < 0.05 (molecular comparisons) or Q < 0.25 (Gene Set Enrichment Analysis [GSEA]). Insurance claims data were used for survival analysis.

RESULTS

The study included 5,587 patients with BTC (453 eoBTC, median age = 44 years and 5,134 aoBTC, median age = 68 years). FGFR2 fusion (15.7% in eoBTC v 5.9% in aoBTC) and NIPBL fusion (1.1% v 0%) were significantly more prevalent in eoBTC (both Q < 0.001). The interferon gamma-IFG score (fold change [FC], 1.1; Q = 0.01) and T-cell inflammation score (FC, 17.3; Q = 0.03) were significantly higher in aoBTC. On GSEA, angiogenesis was enriched in eoBTC (normalized enrichment score [NES] = 1.51; Q = 0.16), whereas IFG (NES = -1.58; Q = 0.06) and inflammatory response (NES = -1.46; Q = 0.18) were enriched in aoBTC. The median overall survival (OS) was 16.5 (eoBTC) versus 13.3 months (aoBTC), hazard ratio = 0.86, P = .004. The median OS by FGFR2 fusion (with fusion v without) was 21.7 versus 15.0 months (P = .47) for eoBTC and 18.6 versus 12.2 months (P < .001) for aoBTC.

CONCLUSION

We identified crucial differences including higher prevalence of FGFR2 fusions in eoBTC and variations in immunotherapy-related markers. Better outcomes in eoBTC were affected by the FGFR2 fusion status. Our findings underscore the need for ensuring access to next-generation sequencing testing, including prompt identification of actionable targets.

Delineation of the phenotypes and genotypes of PIK3CA-related overgrowth spectrum in East asians

PIK3CA-related overgrowth spectrum (PROS) is an umbrella term to describe a diverse range of developmental disorders. Research to date has predominantly emerged from Europe and North America, resulting in a notable scarcity of studies focusing on East Asian populations. Currently, the prevalence and distribution of PIK3CA variants across various genetic loci and their correlation with distinct phenotypes in East Asian populations remain unclear. This study aims to elucidate the phenotype-genotype correlations of PROS in East Asian populations. We presented the phenotypes and genotypes of 82 Chinese patients. Among our cohort, 67 individuals carried PIK3CA variants, including missense, frameshift, and splice variants. Six patients presented with both PIK3CA and an additional variant. Seven PIK3CA-negative patients exhibited overlapping PROS manifestations with variants in GNAQ, AKT1, PTEN, MAP3K3, GNA11, or KRAS. An integrative review of the literature pertaining to East Asian populations revealed that specific variants are uniquely associated with certain PROS phenotypes. Some rare variants were exclusively identified in cases of megalencephaly and diffuse capillary malformation with overgrowth. Non-hotspot variants with undefined oncogenicity were more common in CNS phenotypes. Diseases with vascular malformation were more likely to have variants in the helical domain, whereas phenotypes involving adipose/muscle overgrowth without vascular abnormalities predominantly presented variants in the C2 domain. Our findings underscore the unique phenotype-genotype patterns within the East Asian PROS population, highlighting the necessity for an expanded cohort to further elucidate these correlations. Such endeavors would significantly facilitate the development of PI3Kα selective inhibitors tailored for the East Asian population in the future.

Clinical and Immunologic Characteristics of Colorectal Cancer Tumors Expressing LY6G6D

The identification of targets that are expressed on the cell membrane is a main goal in cancer research. The Lymphocyte Antigen 6 Family Member G6D (LY6G6D) gene codes for a protein that is mainly present on the surface of colorectal cancer (CRC) cells. Therapeutic strategies against this protein like the development of T cell engagers (TCE) are currently in the early clinical stage. In the present work, we interrogated public genomic datasets including TCGA to evaluate the genomic and immunologic cell profile present in tumors with high expression of LY6G6D. We used data from TCGA, among others, and the Tumor Immune Estimation Resource (TIMER2.0) platform for immune cell estimations and Spearman correlation tests. LY6G6D expression was exclusively present in CRC, particularly in the microsatellite stable (MSS) subtype, and was associated with left-side tumors and the canonical genomic subgroup. Tumors with mutations of APC and p53 expressed elevated levels of LY6G6D. This protein was expressed in tumors with an inert immune microenvironment with an absence of immune cells and co-inhibitory molecules. In conclusion, we described clinical, genomic and immune-pathologic characteristics that can be used to optimize the clinical development of agents against this target. Future studies should be performed to confirm these findings and potentially explore the suggested clinical development options.

Impact of tumor size on overall survival and cancer-specific survival of early-onset colon and rectal cancer: a retrospective cohort study

PURPOSE

This study aimed to investigate the impact of tumor size on survival in early-onset colon and rectal cancer.

METHODS

Early-onset colon and rectal cancer patients were identified from the Surveillance, Epidemiology, and End Results (SEER) database between 2004 and 2015. Tumor size was analyzed as both continuous and categorical variables. Several statistical techniques, including restricted cubic spline (RCS), Cox proportional hazard model, subgroup analysis, propensity score matching (PSM), and Kaplan-Meier survival analysis, were employed to demonstrate the association between tumor size and overall survival (OS) and cancer-specific survival (CSS) of early-onset colon and rectal cancer.

RESULTS

Seventeen thousand five hundred fifty-one (76.7%) early-onset colon and 5323 (23.3%) rectal cancer patients were included. RCS analysis confirmed a linear association between tumor size and survival. Patients with a tumor size > 5 cm had worse OS and CSS, compared to those with a tumor size ≤ 5 cm for both early-onset colon and rectal cancer. Notably, subgroup analysis showed that a smaller tumor size (≤ 50 mm) was associated with worse survival in stage II early-onset colon cancer, although not statistically significant. After PSM, Kaplan-Meier survival curves showed that the survival of patients with tumor size ≤ 50 mm was better than that of patients with tumor size > 50 mm.

CONCLUSION

Patients with tumors larger than 5 cm were associated with worse survival in early-onset colon and rectal cancer. However, smaller tumor size may indicate a more biologically aggressive phenotype, correlating with poorer survival in stage II early-onset colon cancer.

The histological and molecular characteristics of early-onset colorectal cancer: a systematic review and meta-analysis

Background

Early-onset colorectal cancer (CRC), defined as diagnosis before age 50, has increased in recent decades. Although more often diagnosed at advanced stage, associations with other histological and molecular markers that impact prognosis and treatment remain to be clarified. We conducted a systematic review and meta-analysis concerning the prevalence of prognostic and predictive tumor markers for early- vs. late-onset CRC, including oncogene mutations, microsatellite instability (MSI), and emerging markers including immune cells and the consensus molecular subtypes.

Methods

We systematically searched PubMed for original research articles published between April 2013-January 2024. Included studies compared the prevalence of tumor markers in early- vs. late-onset CRC. A meta-analysis was completed and summary odds ratios (ORs) with 95% confidence intervals (CIs) were obtained from a random effects model via inverse variance weighting. A sensitivity analysis was completed to restrict the meta-analysis to studies that excluded individuals with Lynch syndrome, a hereditary condition that influences the distribution of tumor markers for early-onset CRC.

Results

In total, 149 articles were identified. Tumors from early-onset CRC are less likely to include mutations in KRAS (OR, 95% CI: 0.91, 0.85-0.98), BRAF (0.63, 0.51-0.78), APC (0.70, 0.58-0.84), and NRAS (0.88, 0.78-1.00) but more likely to include mutations in PTEN (1.68, 1.04-2.73) and TP53 (1.34, 1.24-1.45). After limiting to studies that excluded Lynch syndrome, the associations between early-onset CRC and BRAF (0.77, 0.64-0.92) and APC mutation (0.81, 0.67-0.97) were attenuated, while an inverse association with PIK3CA mutation was also observed (0.88, 0.78-0.99). Early-onset tumors are less likely to develop along the CpG Island Methylator Phenotype pathway (0.24, 0.10-0.57), but more likely to possess adverse histological features including high tumor grade (1.20, 1.15-1.25), and mucinous (1.22, 1.16-1.27) or signet ring histology (2.32, 2.08-2.57). A positive association with MSI status (1.31, 1.11-1.56) was also identified. Associations with immune markers and the consensus molecular subtypes are inconsistent.

Discussion

A lower prevalence of mutations in KRAS and BRAF is consistent with extended survival and superior response to targeted therapies for metastatic disease. Conversely, early-onset CRC is associated with aggressive histological subtypes and TP53 and PTEN mutations, which may serve as therapeutic targets.

Birth Cohort Colorectal Cancer (CRC): Implications for Research and Practice

Colorectal cancer (CRC) epidemiology is changing due to a birth cohort effect, first recognized by increasing incidence of early onset CRC (EOCRC, age <50 years). In this paper, we define "birth cohort CRC" as the observed phenomenon, among individuals born 1960 and later, of increasing CRC risk across successive birth cohorts, rising EOCRC incidence, increasing incidence among individuals aged 50 to 54 years, and flattening of prior decreasing incidence among individuals aged 55 to 74 years. We demonstrate birth cohort CRC is associated with unique features, including increasing rectal cancer (greater than colon) and distant (greater than local) stage CRC diagnosis, and increasing EOCRC across all racial/ethnic groups. We review potential risk factors, etiologies, and mechanisms for birth cohort CRC, using EOCRC as a starting point and describing importance of viewing these through the lens of birth cohort. We also outline implications of birth cohort CRC for epidemiologic and translational research, as well as current clinical practice. We postulate that recognition of birth cohort CRC as an entity-including and extending beyond rising EOCRC-can advance understanding of risk factors, etiologies, and mechanisms, and address the public health consequences of changing CRC epidemiology.

Targeted regulated cell death with small molecule compounds in colorectal cancer: Current perspectives of targeted therapy and molecular mechanisms

Colorectal cancer (CRC), a tumor of the digestive system, is characterized by high malignancy and poor prognosis. Currently, targeted therapy of CRC is far away from satisfying. The molecular mechanisms of regulated cell death (RCD) have been clearly elucidated, which can be intervened by drug or genetic modification. Numerous studies have provided substantial evidence linking these mechanisms to the progression and treatment of CRC. The RCD includes apoptosis, autophagy-dependent cell death (ADCD), ferroptosis, necroptosis, and pyroptosis, and immunogenic cell death, etc, which provide potential targets for anti-cancer treatment. For the last several years, small-molecule compounds targeting RCD have been a well concerned therapeutic strategy for CRC. This present review aims to describe the function of small-molecule compounds in the targeted therapy of CRC via targeting apoptosis, ADCD, ferroptosis, necroptosis, immunogenic dell death and pyroptosis, and their mechanisms. In addition, we prospect the application of newly discovered cuproptosis and disulfidptosis in CRC. Our review may provide references for the targeted therapy of CRC using small-molecule compounds targeting RCD, including the potential targets and candidate compounds.

Novel insights into genetic susceptibility for colorectal cancer from transcriptome-wide association and functional investigation

BACKGROUND

Transcriptome-wide association studies have been successful in identifying candidate susceptibility genes for colorectal cancer (CRC). To strengthen susceptibility gene discovery, we conducted a large transcriptome-wide association study and an alternative splicing transcriptome-wide association study in CRC using improved genetic prediction models and performed in-depth functional investigations.

METHODS

We analyzed RNA-sequencing data from normal colon tissues and genotype data from 423 European descendants to build genetic prediction models of gene expression and alternative splicing and evaluated model performance using independent RNA-sequencing data from normal colon tissues of the Genotype-Tissue Expression Project. We applied the verified models to genome-wide association studies (GWAS) summary statistics among 58 131 CRC cases and 67 347 controls of European ancestry to evaluate associations of genetically predicted gene expression and alternative splicing with CRC risk. We performed in vitro functional assays for 3 selected genes in multiple CRC cell lines.

RESULTS

We identified 57 putative CRC susceptibility genes, which included the 48 genes from transcriptome-wide association studies and 15 genes from splicing transcriptome-wide association studies, at a Bonferroni-corrected P value less than .05. Of these, 16 genes were not previously implicated in CRC susceptibility, including a gene PDE7B (6q23.3) at locus previously not reported by CRC GWAS. Gene knockdown experiments confirmed the oncogenic roles for 2 unreported genes, TRPS1 and METRNL, and a recently reported gene, C14orf166.

CONCLUSION

This study discovered new putative susceptibility genes of CRC and provided novel insights into the biological mechanisms underlying CRC development.

New Perspectives in Colorectal Cancers Treatment, the Role of MicroRNAs

The main epidemiological and clinical data on colorectal cancer, as well as the features of molecular pathology, are discussed in the literature review. Efforts are being putto identify promising targets, particularly small non-coding nucleotide sequences, which can lead to new treatments for this disease. The discovery of significant mutations that contribute to the development of colorectal tumors is a major step in the advancement of molecular oncology, as these mutations give rise to heterogeneous tumors that differ in their origin. These mutations play a significant role in the progression of the disease and are now being targeted for treatment. The prognosis for a disease is influenced by the patient's sensitivity to antitumor therapy. However, new approaches to finding effective targets for antitumor treatments face new fundamental challenges due to clinical issues. These issues include the epigenetic regulation of markers of oncogenesis, which allows for the development of new therapeutic strategies. RNA interference, in particular, has been linked to non-copying RNA sequences such as microRNAs. These microRNAs are associated with certain processes that can influence all aspects of oncogenesis. The diversity of microRNAs allows for a differentiated approach when treating tumors in various locations.

Pharmaceutical Agents as Potential Drivers in the Development of Early-Onset Colorectal Cancer: Case-Control Study

BACKGROUND

The incidence of early-onset colorectal cancer (EOCRC) rose abruptly in the mid 1990s, is continuing to increase, and has now been noted in many countries. By 2030, 25% of American patients diagnosed with rectal cancer will be 49 years or younger. The large majority of EOCRC cases are not found in patients with germline cancer susceptibility mutations (eg, Lynch syndrome) or inflammatory bowel disease. Thus, environmental or lifestyle factors are suspected drivers. Obesity, sedentary lifestyle, diabetes mellitus, smoking, alcohol, or antibiotics affecting the gut microbiome have been proposed. However, these factors, which have been present since the 1950s, have not yet been conclusively linked to the abrupt increase in EOCRC. The sharp increase suggests the introduction of a new risk factor for young people. We hypothesized that the driver may be an off-target effect of a pharmaceutical agent (ie, one requiring regulatory approval before its use in the general population or an off-label use of a previously approved agent) in a genetically susceptible subgroup of young adults. If a pharmaceutical agent is an EOCRC driving factor, regulatory risk mitigation strategies could be used.

OBJECTIVE

We aimed to evaluate the possibility that pharmaceutical agents serve as risk factors for EOCRC.

METHODS

We conducted a case-control study. Data including demographics, comorbidities, and complete medication dispensing history were obtained from the electronic medical records database of Maccabi Healthcare Services, a state-mandated health provider covering 26% of the Israeli population. The participants included 941 patients with EOCRC (≤50 years of age) diagnosed during 2001-2019 who were density matched at a ratio of 1:10 with 9410 control patients. Patients with inflammatory bowel disease and those with a known inherited cancer susceptibility syndrome were excluded. An advanced machine learning algorithm based on gradient boosted decision trees coupled with Bayesian model optimization and repeated data sampling was used to sort through the very high-dimensional drug dispensing data to identify specific medication groups that were consistently linked with EOCRC while allowing for synergistic or antagonistic interactions between medications. Odds ratios for the identified medication classes were obtained from a conditional logistic regression model.

RESULTS

Out of more than 800 medication classes, we identified several classes that were consistently associated with EOCRC risk across independently trained models. Interactions between medication groups did not seem to substantially affect the risk. In our analysis, drug groups that were consistently positively associated with EOCRC included beta blockers and valerian (Valeriana officinalis). Antibiotics were not consistently associated with EOCRC risk.

CONCLUSIONS

Our analysis suggests that the development of EOCRC may be correlated with prior use of specific medications. Additional analyses should be used to validate the results. The mechanism of action inducing EOCRC by candidate pharmaceutical agents will then need to be determined.

Clinical Multigene Panel Testing Identifies Racial and Ethnic Differences in Germline Pathogenic Variants Among Patients With Early-Onset Colorectal Cancer

PURPOSE

The early-onset colorectal cancer (EOCRC) burden differs across racial/ethnic groups, yet the role of germline genetic predisposition in EOCRC disparities remains uncharacterized. We defined the prevalence and spectrum of inherited colorectal cancer (CRC) susceptibility gene variations among patients with EOCRC by race and ethnicity.

PATIENTS AND METHODS

We included individuals diagnosed with a first primary CRC between age 15 and 49 years who identified as Ashkenazi Jewish, Asian, Black, Hispanic, or White and underwent germline genetic testing of 14 CRC susceptibility genes performed by a clinical testing laboratory. Variant comparisons by racial and ethnic groups were evaluated using chi-square tests and multivariable logistic regression adjusted for sex, age, CRC site, and number of primary colorectal tumors.

RESULTS

Among 3,980 patients with EOCRC, a total of 530 germline pathogenic or likely pathogenic variants were identified in 485 individuals (12.2%). By race/ethnicity, 12.7% of Ashkenazim patients, 9.5% of Asian patients, 10.3% of Black patients, 14.0% of Hispanic patients, and 12.4% of White patients carried a germline variant. The prevalence of Lynch syndrome (P = .037), as well as APC, CHEK2, MLH1, monoallelic MUTYH, and PTEN variants, varied by race/ethnicity among patients with EOCRC (all P < .026). Ashkenazim and Hispanic patients had significantly higher odds of presenting with a pathogenic APC variant, which included p.I1307K (odds ratio [OR], 2.67; 95% CI, 1.30 to 5.49; P = .007) and MLH1 variant (OR, 8.69; 95% CI, 2.68 to 28.20; P = .0003), respectively, versus White patients in adjusted models.

CONCLUSION

Germline genetic features differed by race/ethnicity in young patients with CRC, suggesting that current multigene panel tests may not be representative of EOCRC risk in diverse populations. Further study is needed to optimize genes selected for genetic testing in EOCRC via ancestry-specific gene and variant discovery to yield equitable clinical benefits for all patients and to mitigate inequities in disease burden.

Precision medicine and the problem of structural injustice

Many countries currently invest in technologies and data infrastructures to foster precision medicine (PM), which is hoped to better tailor disease treatment and prevention to individual patients. But who can expect to benefit from PM? The answer depends not only on scientific developments but also on the willingness to address the problem of structural injustice. One important step is to confront the problem of underrepresentation of certain populations in PM cohorts via improved research inclusivity. Yet, we argue that the perspective needs to be broadened because the (in)equitable effects of PM are also strongly contingent on wider structural factors and prioritization of healthcare strategies and resources. When (and before) implementing PM, it is crucial to attend to how the organisation of healthcare systems influences who will benefit, as well as whether PM may present challenges for a solidaristic sharing of costs and risks. We discuss these issues through a comparative lens of healthcare models and PM-initiatives in the United States, Austria, and Denmark. The analysis draws attention to how PM hinges on-and simultaneously affects-access to healthcare services, public trust in data handling, and prioritization of healthcare resources. Finally, we provide suggestions for how to mitigate foreseeable negative effects.

A Multi-Omics Overview of Colorectal Cancer to Address Mechanisms of Disease, Metastasis, Patient Disparities and Outcomes

Human colorectal cancer (CRC) is one of the most common malignancies in men and women across the globe, albeit CRC incidence and mortality shows a substantial racial and ethnic disparity, with the highest burden in African American patients. Even with effective screening tools such as colonoscopy and diagnostic detection assays, CRC remains a substantial health burden. In addition, primary tumors located in the proximal (right) or distal (left) sides of the colorectum have been shown to be unique tumor types that require unique treatment schema. Distal metastases in the liver and other organ systems are the major causes of mortality in CRC patients. Characterizing genomic, epigenomic, transcriptomic and proteomic (multi-omics) alterations has led to a better understanding of primary tumor biology, resulting in targeted therapeutic advancements. In this regard, molecular-based CRC subgroups have been developed that show correlations with patient outcomes. Molecular characterization of CRC metastases has highlighted similarities and differences between metastases and primary tumors; however, our understanding as to how to improve patient outcomes based on metastasis biology is lagging and remains a major obstacle to improving CRC patient outcomes. In this review, we will summarize the multi-omics features of primary CRC tumors and their metastases across racial and ethnic groups, the differences in proximal and distal tumor biology, molecular-based CRC subgroups, treatment strategies and challenges for improving patient outcomes.