Molecular Analyses of Left- and Right-Sided Tumors in Adolescents and Young Adults with Colorectal Cancer

New insights in ubiquitin-dependent Wnt receptor regulation in tumorigenesis

Wnt signaling plays a crucial role in embryonic development and homeostasis maintenance. Delicate and sensitive fine-tuning of Wnt signaling based on the proper timings and positions is required to balance cell proliferation and differentiation and maintain individual health. Therefore, homeostasis is broken by tissue hypoplasia or tumor formation once Wnt signal dysregulation disturbs the balance of cell proliferation. The well-known regulatory mechanism of Wnt signaling is the molecular reaction associated with the cytoplasmic accumulation of effector β-catenin. In addition to β-catenin, most Wnt effector proteins are also regulated by ubiquitin-dependent modification, both qualitatively and quantitatively. This review will explain the regulation of the whole Wnt signal in four regulatory phases, as well as the different ubiquitin ligases and the function of deubiquitinating enzymes in each phase. Along with the recent results, the mechanism by which RNF43 negatively regulates the surface expression of Wnt receptors, which has recently been well understood, will be detailed. Many RNF43 mutations have been identified in pancreatic and gastrointestinal cancers and examined for their functional alteration in Wnt signaling. Several mutations facilitate or activate the Wnt signal, reversing the RNF43 tumor suppressor function into an oncogene. RNF43 may simultaneously play different roles in classical multistep tumorigenesis, as both wild-type and mutant RNF43 suppress the p53 pathway. We hope that the knowledge obtained from further research in RNF43 will be applied to cancer treatment in the future despite the fully unclear function of RNF43.

Early-Onset Colorectal Cancer in Egypt: Pathological Characters, Patterns of Care, and Survival Compared to Average-Age Onset Colorectal Cancer: A Retrospective Multicenter Study

PURPOSE

Early-onset colorectal cancer (EOCRC) is a rising health problem. The incidence of EOCRC has increased over the past 2 decades all over the world. Reports from Egypt since the 1990s have reported a higher incidence among young populations with no identifiable risk factors. The aim of this study was to assess EOCRC in Egypt regarding incidence, characteristics, treatment pattern, and survival compared with average age onset and elderly patients.

MATERIALS AND METHODS

This was a retrospective, record-based, cohort study combining data from four different cancer centers in Egypt. We grouped patients according to age into three categories: the EOCRC group for patients age ≤45 years and the average age onset and elderly cancer group (for patients age ≥65 years).

RESULTS

The study included 1,310 patients with histopathologically proven colorectal cancer, representing four different geographical areas in Egypt. Patients with EOCRC represented 42.4% of the study population. Female patients were 50.6% among the EOCRC group and 52.5% among the average age group. Rectal tumors were significantly higher in EOCRC (54.7% v 40.6%; P < .001). There was no significant difference between both groups regarding the tumor stage at presentation, obstruction, or presence of metastases at presentation. Patients with EOCRC had a significantly higher rate of peritoneum/adnexa metastases than the average age ones (12.3% in EOCRC v 6.9% in the average age group; P < .001). No statistically significant differences between EOCRC and average age groups in both disease-free survival and overall survival were reported.

CONCLUSION

A comprehensive framework for the study of EOCRC is required in Egypt as well as a genomic analysis to identify possible underlying genetic alterations responsible for the high incidence of EOCRC.

Histone methyltransferase KMT2D inhibits ENKTL carcinogenesis by epigenetically activating SGK1 and SOCS1

BACKGROUND

Epigenetic alteration plays an essential role in the occurrence and development of extranodal natural killer/T cell lymphoma (ENKTL). Histone methyltransferase (HMT) KMT2D is an epigenetic regulator that plays different roles in different tumors, but its role and mechanism in ENKTL are still unclear.

METHODS

We performed immunohistochemical staining of 112 ENKTL formalin-fixed paraffin-embedded (FFPE) samples. Then, we constructed KMT2D knockdown cell lines and conducted research on cell biological behavior. Finally, to further investigate KMT2D-mediated downstream genes, ChIP-seq and ChIP -qPCR was performed.

RESULTS

The low expression of KMT2D was related to a decreased abundance in histone H3 lysine 4 mono- and trimethylation (H3K4me1/3). In KMT2D knockdown YT and NK-YS cells, cell proliferation was faster (P < 0.05), apoptosis was decreased (P < 0.05), the abundance of S phase cells was increased (P < 0.05), and the level of H3K4me1 was decreased. Notably, ChIP-seq revealed two crucial genes and pathways downregulated by KMT2D.

CONCLUSIONS

KMT2D is a tumor suppressor gene that mediates H3K4me1 and influences ENKTL proliferation and apoptosis by regulating the cell cycle. Moreover, in ENKTL, serum- and glucocorticoid-inducible kinase-1 (SGK1) and suppressor of cytokine signaling-1 (SOCS1) are downstream genes of KMT2D.

Management and pharmacotherapy of pediatric colorectal carcinoma: a review

INTRODUCTION

Colorectal carcinoma (CRC) is one of the most common tumors in adult, but is extremely rare in children. In childhood, CRC often presents unfavorable aggressive histotypes, advanced clinical stage at onset and a worse prognosis. Pediatric CRC series are limited and include few patients, therefore information about treatment strategy and pharmacotherapy is scarce. For this reason, management of these patients represents a real challenge for pediatric oncologists.

AREAS COVERED

The authors provide an overview of the general features and management strategies of pediatric CRC with specific attention to systemic treatment. Literature data regarding pharmacotherapy in published pediatric series are summarized and analyzed in detail, according to adult treatment standards.

EXPERT OPINION

In the absence of specific recommendations for pediatric CRC, the general therapeutic strategy should follow the same principles as for adults and should be the result of a multidisciplinary discussion. Patient access to optimal treatment is difficult due to the lack of new drugs approved for the pediatric age group and non-availability of clinical trials. Collaboration between pediatric and adult oncologists is considered crucial in order to overcome these issues and find solutions to increase knowledge and improve the outcome of such a rare disease in children.

Colorectal cancer in adolescent and young adults: epidemiology in Japan and narrative review

Background and Objective

Although only a small proportion of colorectal cancer (CRC) cases develop in adolescents and young adults (AYAs), its incidence has increased recently. We aimed to conduct a narrative literature review and summarize the epidemiology, clinicopathological features, genetics, and treatments for AYA-CRCs.

Methods

We searched the articles published in the PubMed database until November 30, 2022, with keywords, "((adolescent and young adult) OR AYA) AND ((colorectal cancer) OR (colon cancer) OR (rectal cancer))" and "young-onset AND ((colorectal cancer) OR (colon cancer) OR (rectal cancer))".

Key Content and Findings

In Japan, the annual incidence of AYA-CRC was approximately 1,200 in the 1970s, but has increased to 2,000 nowadays. An increased incidence of AYA-CRC has also been reported in other countries. AYA-CRC tends to be a more advanced disease at presentation than CRC in older patients, with more adverse histological features and variability in molecular characteristics. Diagnosis of CRC is often delayed in AYAs because they are not invited to undergo cancer screening. Three to five percent of patients with AYA-CRC have hereditary cancer syndromes such as Lynch syndrome and familial adenomatous polyposis (FAP), and a family history should be obtained. Additionally, providing information on fertility preservation and social systems before starting treatment is important for sustainable treatment and life after cancer treatment.

Conclusions

The number of AYA-CRC cases is increasing in Japan. Before initiating treatment for AYA-CRC, we should know that these patients may have a hereditary disease and fertility preservation should be explained. More physicians should be aware of the importance of AYA-CRC.

KRAS Mutation Status in Bulgarian Patients with Advanced and Metastatic Colorectal Cancer

RAS somatic variants are predictors of resistance to anti-EGFR therapy for colorectal cancer (CRC) and affect the outcome of the disease. Our study aimed to evaluate the frequency of RAS, with a focus on KRAS variants, and their association with tumor location and some clinicopathological characteristics in Bulgarian CRC patients. We prospectively investigated 236 patients with advanced and metastatic CRC. Genomic DNA was extracted from FFPE tumor tissue samples, and commercially available kits were used to detect RAS gene somatic mutations via real-time PCR. A total of 115 (48.73%) patients tested positive for RAS mutations, with 106 (44.92%) testing positive for KRAS mutations. The most common mutation in exon 2 was c.35G>T p.Gly12Val (32.56%). We did not find a significant difference in KRAS mutation frequency according to tumor location. However, patients with a mutation in exon 4 of KRAS were 3.23 times more likely to have a tumor in the rectum than in other locations (95% CI: 1.19-8.72, p = 0.021). Studying the link between tumor location and KRAS mutations in exon 4 is crucial for better characterizing CRC patients. Further research with larger cohorts, especially in rectal cancer patients, could provide valuable insights for patient follow-up and treatment selection.

Impact of Colorectal Cancer Sidedness and Location on Therapy and Clinical Outcomes: Role of Blood-Based Biopsy for Personalized Treatment

Colorectal cancer is one of the most common malignant diseases in the United States and worldwide, and it remains among the top three causes of cancer-related death. A new understanding of molecular characteristics has changed the profile of colorectal cancer and its treatment. Even controlling for known mutational differences, tumor side of origin has emerged as an independent prognostic factor, and one that impacts response to therapy. Left- and right-sided colon cancers differ in a number of key ways, including histology, mutational profile, carcinogenesis pathways, and microbiomes. Moreover, the frequency of certain molecular features gradually changes from the ascending colon to rectum. These, as well as features yet to be identified, are likely responsible for the ongoing role of tumor sidedness and colorectal subsites in treatment response and prognosis. Along with tumor molecular profiling, blood-based biopsy enables the identification of targetable mutations and predictive biomarkers of treatment response. With the application of known tumor characteristics including sidedness and subsites as well as the utilization of blood-based biopsy, along with the development of biomarkers and targeted therapies, the field of colorectal cancer continues to evolve towards the personalized management of a heterogeneous cancer.

The Prognostic Utilities of DNA Mismatch Repair Status and KRAS and BRAF Mutation in Korean Colorectal Cancer Patients: The KASID Multicenter Study

INTRODUCTION

KRAS, BRAF, and DNA mismatch repair (MMR) mutations aid clinical decision-making for colorectal cancer (CRC) patients. To ensure accurate predictions, the prognostic utilities of these biomarkers and their combinations must be individualized for patients with various TNM stages.

METHODS

Here, we retrospectively analyzed the clinicopathological features of 904 Korean CRC patients who underwent CRC surgery in three teaching hospitals from 2011 to 2013; we also assessed the prognostic utilities of KRAS, BRAF, and MMR mutations in these patients.

RESULTS

The overall frequencies of KRAS and BRAF mutations were 35.8% and 3.2%, respectively. Sixty-nine patients (7.6%) lacking expression of ≥1 MMR protein were considered MMR protein deficient (MMR-D); the remaining patients were considered MMR protein intact. KRAS mutations constituted an independent risk factor for shorter overall survival (OS) in TNM stage I-IV and stage III patients. BRAF mutations were associated with shorter OS in TNM stage I-IV patients. MMR-D status was strongly positive prognostic in TNM stage I-II patients.

DISCUSSION/CONCLUSION

To our knowledge, this is the first multicenter study to explore the prognostic utilities of KRAS, BRAF, and MMR statuses in Korean CRC patients. Various combinations of KRAS, BRAF, and DNA MMR mutations serve as genetic signatures that affect tumor behavior; they are prognostic in CRC patients.

Selective Role of TNFα and IL10 in Regulation of Barrier Properties of the Colon in DMH-Induced Tumor and Healthy Rats

Recently it has been reported that the tumor adjacent colon tissues of 1,2-dymethylhydrazine induced (DMH)-rats revealed a high paracellular permeability. We hypothesized that the changes might be induced by cytokines. Colorectal cancer is accompanied by an increase in tumor necrosis factor alpha (TNFα) and interleukin 10 (IL10) that exert opposite regulatory effects on barrier properties of the colon, which is characterized by morphological and functional segmental heterogeneity. The aim of this study was to analyze the level of TNFα and IL10 in the colon segments of DMH-rats and to investigate their effects on barrier properties of the proximal and distal parts of the colon in healthy rats. Enzyme immunoassay analysis showed decreased TNFα in tumors in the distal part of the colon and increased IL10 in proximal tumors and in non-tumor tissues. Four-hour intraluminal exposure of the colon of healthy rats with cytokines showed reduced colon barrier function dependent on the cytokine: TNFα decreased it mainly in the distal part of the colon, whereas IL10 decreased it only in the proximal part. Western blot analysis revealed a more pronounced influence of IL10 on tight junction (TJ) proteins expression by down-regulation of the TJ proteins claudin-1, -2 and -4, and up-regulation of occludin only in the proximal part of the colon. These data may indicate a selective role of the cytokines in regulation of the barrier properties of the colon and a prominent role of IL10 in carcinogenesis in its proximal part.

Prevalence and Genotype-Phenotype Correlation of Lynch Syndrome in a Selected High-Risk Cohort from Qatar’s Population

Lynch syndrome (LS) is the most common cause of hereditary colorectal cancers (CRC) and is associated with an increased risk for ovarian and endometrial cancers. There is lack of knowledge on the epidemiology of LS in the non-Caucasian populations especially in Qatar. The aim of this retrospective study is to explore the prevalence of LS in a selected high-risk cohort in the State of Qatar in addition to investigating the frequency and genotype-phenotype correlation associated with mismatch repair genes pathogenic variants. Retrospective review of medical records of 31 individuals with LS, 20 affected with colorectal cancer and 11 unaffected with family history of cancers, referred from January 2017 until August 2020. The prevalence of LS among affected and unaffected patients is 22% (20/92) and 2.2% respectively. Among affected individuals, MLH1 and MSH2 genes were highly frequent while for unaffected individuals, a recurrent PMS2 pathogenic variant was reported in several related individuals suggesting a tribal effect. This study highlights the epidemiology of LS in high-risk cohort in Qatar which helps to provide recommendations on genetic testing, and personalize surveillance and management programs

Biomarkers in Metastatic Colorectal Cancer: Status Quo and Future Perspective

Colorectal cancer (CRC) is the third most frequent cancer worldwide, and its incidence is steadily increasing. During the last two decades, a tremendous improvement in outcome has been achieved, mainly due to the introduction of novel drugs, targeted treatment, immune checkpoint inhibitors (CPIs) and biomarker-driven patient selection. Moreover, progress in molecular diagnostics but also improvement in surgical techniques and local ablative treatments significantly contributed to this success. However, novel therapeutic approaches are needed to further improve outcome in patients diagnosed with metastatic CRC. Besides the established biomarkers for mCRC, such as microsatellite instability (MSI) or mismatch repair deficiency (dMMR), RAS/BRAF, sidedness and HER2 amplification, new biomarkers have to be identified to better select patients who derive the most benefit from a specific treatment. In this review, we provide an overview about therapeutic relevant and established biomarkers but also shed light on potential promising markers that may help us to better tailor therapy to the individual mCRC patient in the near future.

Microsatellite Instability: From the Implementation of the Detection to a Prognostic and Predictive Role in Cancers

Microsatellite instability (MSI) has been identified in several tumors arising from either germline or somatic aberration. The presence of MSI in cancer predicts the sensitivity to immune checkpoint inhibitors (ICIs), particularly PD1/PD-L1 inhibitors. To date, the predictive role of MSI is currently used in the selection of colorectal cancer patients for immunotherapy; moreover, the expansion of clinical trials into other cancer types may elucidate the predictive value of MSI for non-colorectal tumors. In clinical practice, several assays are used for MSI testing, including immunohistochemistry (IHC), polymerase chain reaction (PCR) and next-generation sequencing (NGS). In this review, we provide an overview of MSI in various cancer types, highlighting its potential predictive/prognostic role and the clinical trials performed. Finally, we focus on the comparison data between the different assays used to detect MSI in clinical practice.

Exome sequencing revealed comparable frequencies of RNF43 and BRAF mutations in Middle Eastern colorectal cancer

Mutation-induced activation of Wnt-β Catenin signaling pathway is frequent in CRC. The E3 ubiquitin ligase, RNF43, has been reported to negatively regulate the Wnt signaling pathway and RNF43 mutations are frequently seen in CRC. However, its role in Middle Eastern CRC remains unclear. Therefore, we employed Exome and Sanger sequencing technology to assess the frequency of RNF43 mutations and its association with other clinico-pathological features in Middle Eastern CRC. RNF43 mutations were found in 5.9% (13/220) of CRC cases and was inversely correlated to APC and TP53 mutations. A strong association of RNF43 mutations with right sided and sporadic microsatellite instable (MSI) CRC was observed. No association was identified between RNF43 mutation and other clinico-pathological features including BRAF mutation, age, tumor histological subtype, tumor grade or patients’ prognosis. Multivariate logistic regression analysis revealed that MSI status and wild type APC were independent predictor of RNF43 mutation. We conclude that RNF43 mutations occur in Middle Eastern CRC at comparable frequencies with BRAF mutations and represent a distinct molecular subtype which further enhances our understanding of how different mutational subsets of Wnt tumor suppressor genes link to distinct tumor characteristics, which might be considered for treatment strategies for CRC patients.

Correlation of KMT2 family mutations with molecular characteristics and prognosis in colorectal cancer

BACKGROUND

Lysine methyltransferase 2 (KMT2) family proteins methylate lysine 4 on histone H3 (H3K4) to promote genome accessibility and transcription. Dysregulation or mutation of KMT2 family have been observed frequently in various types of human cancers. Colorectal cancer is the third most common cancer worldwide. However, few studies have evaluated the role of KMT2 family mutations in colorectal cancer. The present study aimed to explore the impact of KMT2 family mutations on clinicopathological, molecular characteristics and prognosis in colorectal cancer.

METHODS

A total of 316 colorectal cancer patients were enrolled; tumor tissue and matched peripheral blood samples were collected and subjected to targeted sequencing with a panel of 1021 cancer-related genes. The association of clinical pathological features and molecular characteristics in patients were then analyzed. The cBioPortal dataset was used for investigating the KMT2 family mutations data and their correlation with clinical outcomes.

RESULTS

The overall mutation frequencies of KMT2A-D were 9.5%, 0.5%, 13%, and 13%, respectively, which were more often present at right-sided primary and earlier stage tumors. KMT2A-D mutations are associated with enhanced genomic instability, including a higher level of microsatellite instability (MSI-H) and tumor mutational burden (TMB-H). In addition, our results highlight the co-occurring gene mutations within the Wnt signaling, ERBB2/4, TGF-β superfamily pathway, and PI-3-kinase pathway in KMT2-mutant colorectal cancer. KMT2 family mutations were predictive biomarker for better overall survival in metastatic colorectal cancer.

CONCLUSIONS

Collectively, we identified that KMT2 family mutations were correlated with higher-TMB and higher-MSI, thus resulting in a better outcome for colorectal cancer patients.

Concurrent BRAFV600E and BRCA Mutations in MSS Metastatic Colorectal Cancer: Prevalence and Case Series of mCRC patients with prolonged OS

BACKGROUND

BRAF V600E+ microsatellite stable (MSS) metastatic colorectal cancer (mCRC) patients comprise up to 10% of advanced CRC. They have a poor prognosis with a median survival typically <1 year. Despite use of multi-agent 1^st line chemotherapy regimens and combination targeted therapies, outcomes are still poor. In our Institutional Molecular Tumor Board (MTB) database, we identified 3 mCRC patients with MSS/BRAF V600E who also had a BRCA1 or BRCA2 co-mutation and had relatively long overall survivals. Prior studies suggested that BRCA mutations are uncommon in CRC and we queried the Foundation Medicine (FM) genomic database to evaluate the prevalence of these cases as well as those with co-mutations in other homologous recombination genes.

METHODS

36,966 CRC pts were sequenced by FMI using hybrid capture comprehensive genomic profiling (CGP) to evaluate all classes of genomic alterations (GA) for pathogenic BRAF mutations and/or a mutation in BRCA1/2 or a co-mutation in other homologous recombination (HR) genes (BARD1, CDK12, FANCL, PALB2, ATM, RAD54L, CHEK2, BRAF, BRIP1, RAD51D, RAD51C, RAD51B, CHEK1). Selected cohort analysis of BRAF V600E co-mutated with BRCA1 and BRCA2 were separated into MSI-H and MSS cohorts. The clinicopathological features and genomic loss of heterozygosity (gLOH) of those with a BRAF V600E and a BRCA1/BRCA2 mutation were collected and analyzed. We also describe 3 consecutive cases of mCRC patients, identified through the Inova Schar Cancer Institute (ISCI) MTB registry, whom had prolonged OS.

RESULTS

Of 36,966 colorectal cancer pts, 6.6% were BRAF V600E+ and 1.5% had any co-occurring HR gene mutation(s) with 0.6% of the total mCRC population having co-ocurring BRAF V600E and BRCA1/2 alterations. BRCA co-mutations were higher in MSI-High BRAF V600E, however 24.1% of co-occurrences were observed in MSS samples. BRCA1 co-mutation was more commonly associated with MSS BRAF V600E and was associated with a higher gLOH than MSI-H BRAF V600E (18.7% vs 2.8%; p <0.001). In our institutional MTB database, (3/241;1.2%) CRC patients were MSS, BRAF V600E+ with BRCA1 or BRCA2 co-mutations, all somatic in origin, with an average gLOH of 21.4% and overall survivals of 72+(alive), 17+(alive), and 30 months, respectively.

CONCLUSION

Co-existence of BRAF V600E/BRCA1/2 may represent a unique subset of advanced MSS CRC that may have a better prognosis and represent an opportunity to test novel targeted therapies. The elevated gLOH in these cases may also be a valuable biomarker for these pts. Larger prospective clinical validation trials in this subset is warranted.

Assessing the Impact of Primary Tumour Location on Survival After Resection of Colorectal Liver Metastases: A Propensity Weighted Retrospective Cohort Study

BACKGROUND

Right-sided colonic tumours appear to have poorer survival after resection of colorectal liver metastases, although this may be confounded by various factors including advanced stage and emergency presentation.

METHODS

Medical records of consecutive patients undergoing resection of colorectal liver metastases at a single centre from 2008 to 2015 were retrospectively reviewed. Cases were categorised by primary tumour location (right colon, left colon, rectum). Each primary location was weighted using propensity scores to balance covariates, including staging and mode of presentation. Cox regression was then applied to derive multivariable hazard ratios (HR) of survival after liver resection. Primary outcomes were 10-year overall survival (OS) and 5-year disease-free survival (DFS) after liver resection based on PTL.

RESULTS

414 patients were included in the analysis. Left colonic tumours were significantly associated with higher rates of bilobar liver metastasis (36.2% vs. 20.1% and 30.1%) and larger maximum size of liver metastases compared with rectal and right-sided tumours, respectively. There was no difference in rates of extra-hepatic metastases, recurrence in the liver after resection or RAS, BRAF or p53 mutational status. After propensity weighting and Cox-regression, right-sided tumours were independently associated with significantly reduced 10 year OS (HR 1.56, 95% CI 1.03-2.36, p = 0.04) but not 5 year DFS (HR 1.36, 95% CI 0.89-2.08, p = 0.15).

CONCLUSIONS

Compared with left colonic and rectal tumours, right-sided colonic tumours are independently associated with inferior OS after resection of CRLM. This is despite higher rates of bilobar liver metastases and larger metastases with left-sided tumours.

Sarcopenia and primary tumor location influence patients outcome after liver resection for colorectal liver metastases

INTRODUCTION

Right-sided and left-sided colorectal cancer (CRC) is known to differ in their molecular carcinogenic pathways. The prevalence of sarcopenia is known to worsen the outcome after hepatic resection. We sought to investigate the prevalence of sarcopenia and its prognostic application according to the primary CRC tumor site.

METHODS

355 patients (62% male) who underwent liver resection in our center were identified. Clinicopathologic characteristics and long-term outcomes were stratified by sarcopenia and primary tumor location (right-sided vs. left-sided). Tumors in the coecum, right sided and transverse colon were defined as right-sided, tumors in the left colon and rectum were defined as left-sided. Sarcopenia was assessed using the skeletal muscle index (SMI) with a measurement of the skeletal muscle area at the level L3.

RESULTS

Patients who underwent right sided colectomy (n = 233, 65%) showed a higher prevalence of sarcopenia (35.2% vs. 23.9%, p = 0.03). These patients also had higher chances for postoperative complications with Clavien Dindo >3 (OR 1.21 CI95% 0.9-1.81, p = 0.05) and higher odds for mortality related to CRC (HR 1.2 CI95% 0.8-1.8, p = 0.03).On multivariable analysis prevalence of sarcopenia remained independently associated with worse overall survival and disease free survival (overall survival: HR 1.47 CI 95% 1.03-2.46, p = 0.03; HR 1.74 CI95% 1.09-3.4, p = 0.05 respectively).

CONCLUSION

Sarcopenia is known to have a worse prognosis in patients with CRLM and CRC. Depending on the primary location sarcopenia has a variable effect on the outcome after liver resection.

Clinical, Pathology, Genetic, and Molecular Features of Colorectal Tumors in Adolescents and Adults 25 Years or Younger

BACKGROUND & AIMS

Colorectal cancers (CRCs) are rare in adolescents and adults ages 25 years or younger. We analyzed clinical, pathology, and molecular features of colorectal tumors from adolescents and young adults in an effort to improve genetic counseling, surveillance, and, ultimately, treatment and outcomes.

METHODS

We analyzed clinical data and molecular and genetic features of colorectal tumor tissues from 139 adolescents or young adults (age, ≤25 y; median age, 23 y; 58% male), collected from 2000 through 2017; tumor tissues and clinical data were obtained from the nationwide network and registry of histopathology and cytopathology and The Netherlands Cancer Registry, respectively. DNA samples from tumors were analyzed for microsatellite instability, mutations in 56 genes, and genome-wide somatic copy number aberrations.

RESULTS

Mucinous and/or signet ring cell components were observed in 33% of tumor samples. A genetic tumor risk syndrome was confirmed for 39% of cases. Factors associated with shorter survival time included younger age at diagnosis, signet ring cell carcinoma, the absence of a genetic tumor risk syndrome, and diagnosis at an advanced stage of disease. Compared with colorectal tumors from patients ages 60 years or older in the Cancer Genome Atlas, higher proportions of tumors from adolescents or young adults were microsatellite stable with nearly diploid genomes, or contained somatic mutations in TP53 and POLE, whereas lower proportions contained mutations in APC.

CONCLUSIONS

We found clinical, molecular, and genetic features of CRCs in adolescents or young adults to differ from those of patients older than age 60 years. In 39% of patients a genetic tumor risk syndrome was identified. These findings provide insight into the pathogenesis of CRC in young patients and suggest new strategies for clinical management. Performing genetic and molecular analyses for every individual diagnosed with CRC at age 25 years or younger would aid in this optimization.

Impact of Sociodemographic Disparities and Insurance Status on Survival of Patients with Early-Onset Colorectal Cancer

Background

Low socioeconomic status (SES) has been linked to worse survival in patients with colorectal cancer (CRC); however, the impact of SES on early‐onset CRC remains undescribed.

Materials and Methods

Retrospective analysis of data from the National Cancer Database (NCDB) between 2004 and 2016 was conducted. We combined income and education to form a composite measure of SES. Logistic regression and χ² testing were used to examine early‐onset CRC according to SES group. Survival rates and Cox proportional hazards models compared stage‐specific overall survival (OS) between the SES groups.

Results

In total, 30,903 patients with early‐onset CRC were identified, of whom 78.7% were White; 14.5% were Black. Low SES compared with high SES patients were more likely to be Black (26.3% vs. 6.1%) or Hispanic (25.3% vs. 10.5%), have T4 tumors (21.3% vs. 17.8%) and/or N2 disease (13% vs. 11.1%), and present with stage IV disease (32.8% vs. 27.7%) at diagnosis (p < .0001, all comparisons). OS gradually improved with increasing SES at all disease stages (p < .001). In stage IV, the 5‐year survival rate was 13.9% vs. 21.7% for patients with low compared with high SES. In multivariable analysis, SES (low vs. high group; adjusted hazard ratio [HR_adj], 1.35; 95% confidence interval [CI], 1.26–1.46) was found to have a significant effect on survival (p < .0001) when all of the confounding variables were adjusted. Insurance (not private vs. private; HR_adj, 1.38; 95% CI, 1.31–1.44) mediates 31% of the SES effect on survival.

Conclusion

Patients with early‐onset CRC with low SES had the worst outcomes. Our data suggest that SES should be considered when implementing programs to improve the early detection and treatment of patients with early‐onset CRC.

Implications for Practice

Low socioeconomic status (SES) has been linked to worse survival in patients with colorectal cancer (CRC); however, the impact of SES on early‐onset CRC remains undescribed. In this retrospective study of 30,903 patients with early‐onset CRC in the National Cancer Database, a steady increase in the yearly rate of stage IV diagnosis at presentation was observed. The risk of death increased as socioeconomic status decreased. Race and insurance status were independent predictors for survival. Implementation of programs to improve access to care and early diagnostic strategies among younger adults, especially those with low SES, is warranted.

The incidence of and mortality from early‐onset colorectal cancer (CRC) is on the rise. This article details the relationship between socioeconomic status and clinical outcomes of young adults with early‐onset CRC.

The impact of primary tumor sidedness on survival in early-onset colorectal cancer by stage: A National Veterans Affairs retrospective analysis

BACKGROUND

The incidence of early-onset colorectal cancer (EOCRC) is rising. Left-sided colorectal cancer (LCC) is associated with better survival compared to right-sided colon cancer (RCC) in metastatic disease. NCCN guidelines recommend the addition of EGFR inhibitors to KRAS/NRAS WT metastatic CRC originating from the left only. Whether laterality impacts survival in locoregional disease and EOCRC is of interest.

METHODS

65,940 CRC cases from the National VA Cancer Cube Registry (2001-2015) were studied. EOCRC (2096 cases) was defined as CRC diagnosed at <50 years. Using ICD codes, RCC was defined from the cecum to the hepatic flexure (C18.0-C18.3), and LCC from the splenic flexure to the rectum (C18.5-18.7; C19 and C20).

RESULTS

EOCRC is more likely to originate from the left side (66.65% LCC in EOCRC vs. 58.77% in CRC). Overall, LCC has better 5-year Overall Survival (OS) than RCC in stages I (61.67% vs. 58.01%) and III (46.1% vs. 42.1%) and better 1-year OS in stage IV (57.79% vs. 49.49%). Stage II RCC has better 5-year OS than LCC (53.39% vs. 49.28%). In EOCRC, there is no statistically significant difference between LCC and RCC in stages I-III. Stage IV EOCRC patients with LCC and RCC have a 1-year OS of 73.23% and 59.84%, respectively.

CONCLUSION

In EOCRC, LCC is associated with better OS than RCC only stage IV. In the overall population, LCC is associated with better OS in all stages except stage II. The better prognosis of stage II RCC might be due to the high incidence of mismatch repair deficient tumors in this subpopulation.

Mutational spectrum and precision oncology for biliary tract carcinoma

Background: The genomic spectrum of biliary tract carcinoma (BTC) has been characterized and is associated with distinct anatomic and etiologic subtypes, yet limited studies have linked genomic alterations with personalized therapies in BTC patients. Methods: This study analyzed 803 patients with BTC:164 with gallbladder cancer, 475 with intrahepatic cholangiocarcinoma (ICC) and 164 with extrahepatic cholangiocarcinoma. We determined genomic alterations, mutational signatures related to etiology and histopathology and prognostic biomarkers. Personalized targeted therapies for patients harboring potentially actionable targets (PATs) were investigated. Results: The median tumor mutation burden (TMB) was 1.23 Mut/Mb, with 4.1% of patients having hypermutated BTCs. Unlike the results obtained from the Western population, the most frequently altered cancer-related genes in our cohort included TP53 (53%), KRAS (26%), ARID1A (18%), LRP1B (14%) and CDKN2A (14%). Germline mutations occurred mostly in DNA damage repair genes. Notably, 35.8% of the ICCs harbored aristolochic acid related signatures and an elevated TMB. TP53 and KRAS mutations and amplified 7q31.2 were demonstrated to negatively affect patient prognosis. Moreover, 19 genes were proposed to be PATs in BTCs, with 25.4% of patients harboring these PATs. Forty-six patients received PAT-matched targeted therapies, achieving a 26.1% objective response rate; the median progression-free survival (PFS) was 5.0 months, with 56.8% of patients obtaining PFS benefits. Conclusions: Extensive genomic diversity and heterogeneity were observed among BTC patients, with contributions according to potential etiology exposures, anatomical subtypes and clinicopathological characteristics. We also demonstrated that patients with refractory BTCs who have PATs can derive considerable benefit from receiving a matched therapy, initiating further prospective clinical trials guided by molecular profiling among this aggressive cancer.

Post-translational Wnt receptor regulation: Is the fog slowly clearing?: The molecular mechanism of RNF43/ZNRF3 ubiquitin ligases is not yet fully elucidated and still controversial

Wnt signaling plays pivotal roles during our entire lives, from conception to death, through the regulation of morphogenesis in developing embryos and the maintenance of tissue homeostasis in adults. The regulation of Wnt signaling occurs on several levels: at the receptor level on the plasma membrane, at the β-catenin protein level in the cytoplasm, and through transcriptional regulation in the nucleus. Several recent studies have focused on the mechanisms of Wnt receptor regulation, following the discovery that the Wnt receptor frizzled (Fzd) is a target of the ubiquitin ligases, RNF43 and ZNRF3. RNF43 and ZNRF3 are homologous genes that are mutated in several cancers. The details underlying their mechanism of action continue to unfold, while at the same time raising many new questions. In this review, we discuss advances and controversies in our understanding of Wnt receptor regulation.

Mutations and mechanisms of WNT pathway tumour suppressors in cancer

Mutation-induced activation of WNT-β-catenin signalling is a frequent driver event in human cancer. Sustained WNT-β-catenin pathway activation endows cancer cells with sustained self-renewing growth properties and is associated with therapy resistance. In healthy adult stem cells, WNT pathway activity is carefully controlled by core pathway tumour suppressors as well as negative feedback regulators. Gene inactivation experiments in mouse models unequivocally demonstrated the relevance of WNT tumour suppressor loss-of-function mutations for cancer growth. However, in human cancer, a far more complex picture has emerged in which missense or truncating mutations mediate stable expression of mutant proteins, with distinct functional and phenotypic ramifications. Herein, we review recent advances and challenges in our understanding of how different mutational subsets of WNT tumour suppressor genes link to distinct cancer types, clinical outcomes and treatment strategies.

Sexual Dimorphism in Colon Cancer

A higher incidence of colorectal cancer (CRC) is found in males compared to females. Young women (18-44 years) with CRC have a better survival outcome compared to men of the same age or compared to older women (over 50 years), indicating a global incidence of sexual dimorphism in CRC rates and survival. This suggests a protective role for the sex steroid hormone estrogen in CRC development. Key proliferative pathways in CRC tumorigenesis exhibit sexual dimorphism, which confer better survival in females through estrogen regulated genes and cell signaling. Estrogen regulates the activity of a class of Kv channels (KCNQ1:KCNE3), which control fundamental ion transport functions of the colon and epithelial mesenchymal transition through bi-directional interactions with the Wnt/β-catenin signalling pathway. Estrogen also modulates CRC proliferative responses in hypoxia via the novel membrane estrogen receptor GPER and HIF1A and VEGF signaling. Here we critically review recent clinical and molecular insights into sexual dimorphism of CRC biology modulated by the tumor microenvironment, estrogen, Wnt/β-catenin signalling, ion channels, and X-linked genes.

Genomic Alterations and Their Implications on Survival in Nonmetastatic Colorectal Cancer: Status Quo and Future Perspectives

The selection of treatment according to genomic alterations is a standard approach in metastatic colorectal cancer but is only starting to have an impact in the earlier stages of the disease. The status if genes like KRAS, BRAF, and MMR has substantial survival implications, and concerted research efforts have revolutionized treatment towards precision oncology. In contrast, a genomic-based approach has not changed the adjuvant setting after curative tumor-resection in the daily routine so far. This review focuses on the current knowledge regarding prognostic and predictive genomic biomarkers in patients with locally advanced nonmetastasized colorectal cancer. Furthermore, we provide an outlook on future challenges for a personalized adjuvant treatment approach in patients with colorectal cancer.

Surgical management of sarcoma in adolescent and young adult patients

Objective

To examine the clinical features and outcomes of adolescent and young adult sarcoma patients who underwent surgical management and clarify important factors associated with prognosis. We reviewed 18 young adult sarcoma patients sarcoma patients treated surgically in our hospital. The tumor site, histology, grade, stage, and American Society of Anesthesiologists-Physical Status before surgery, operation time, intraoperative blood loss, complications, surgical margin, local recurrence, metastasis, and outcomes were investigated. The 3-year survival rate was also calculated. We compared survival based on age, grade, and surveyed features of poor outcome cases.

Results

The 3-year survival rate was 61.3%. There was no significant difference in survival based on age, grade, operation time, or intraoperative blood loss. Three of five patients who died of the disease had stage ≥ IV at diagnosis. All patients with R1 surgical margins developed recurrence and all those with an American Society of Anesthesiologists-Physical Status ≥ 2 died. Patients with late-stage sarcomas, R1 tumor margin, or high American Society of Anesthesiologists-Physical Status score had poor prognoses. To achieve a favorable outcome in adolescent and young adult sarcoma patients, early detection and obtaining R0 ≥ surgical margin are essential.