Early-onset colorectal cancer in young individuals

Disparities in Characteristics, Access to Care, and Oncologic Outcomes in Young-Onset Colorectal Cancer at a Safety-Net Hospital

PURPOSE

Young-onset colorectal cancer is an emerging cause of significant morbidity and mortality globally. Despite this, limited data exist regarding clinical characteristics and outcomes, particularly in safety-net populations where access to care is limited. We aimed to study disparities in clinical characteristics and outcomes in patients with young-onset colorectal cancer in the safety-net setting.

METHODS

We performed a retrospective review of patients < 50 years old diagnosed and/or treated for colorectal cancer between 2001 and 2017 at a safety-net hospital. Kaplan-Meier and Cox regression models were constructed to compare overall survival (OS), progression-free survival (PFS), and relapse-free survival (RFS) by race and ethnicity, stratifying for relevant clinical and pathologic factors.

RESULTS

A total of 395 young-onset patients diagnosed at a safety-net hospital were identified and 270 were included in the analysis (49.6% Hispanic, 25.9% non-Hispanic Black, 20.0% non-Hispanic White, and 4.4% other). Non-Hispanic White race was independently associated with worse OS (hazzard ratio [HR], 0.53; 95% CI, 0.29 to 0.97), as were lack of insurance, higher clinical stage, and mismatch repair proficiency. There was no significant difference seen in PFS or RFS between racial and ethnic groups.

CONCLUSION

Non-Hispanic White race or ethnicity was found to be independently associated with worse OS in a safety-net population of patients with young-onset colorectal cancer. Other independent predictors of worse OS include higher stage, lack of insurance, and mismatch repair proficiency.

Outcomes of exenteration in cT4 and fixed cT3 stage primary rectal adenocarcinoma: a subgroup analysis of consolidation chemotherapy following neoadjuvant concurrent chemoradiotherapy

PURPOSE

The aim was to evaluate the oncological outcomes and the prognostic factors following pelvic exenteration (PE) in cT4 and fixed cT3 stage primary rectal adenocarcinoma and to study the impact of consolidation chemotherapy following neoadjuvant concurrent chemoradiotherapy (NACRT).

METHODS

A retrospective analysis of a prospectively maintained database of PE from 2013 to 2018.

RESULTS

Out of 2900 colorectal resections, there were 131 pelvic exenterations that were performed, and 100 of these patients had undergone exenteration for primary rectal adenocarcinoma. Of these 100 patients, there were 81 patients who had received NACRT followed by surgery, 50 of whom who had received consolidation chemotherapy and 31 who had undergone surgery without consolidation chemotherapy. R0 resection was achieved in 90% cases. At a median follow-up of 32 months, 2-year disease free survival was 61.8% and estimated 5-year overall survival was 62%. The incidence of distant metastases was 44% vs. 19% (p = 0.023), and the 2-year distant recurrence-free survival was 58% vs. 89% (p = 0.025), respectively, in the 'consolidation chemotherapy group' and the 'no chemotherapy group'. The poorly differentiated grade of tumours, presence of lympho-vascular-invasion, consolidation chemotherapy, and disease recurrence were all found to affect the survival.

CONCLUSION

PE with R0 resection achieves excellent survival rates in cT4 and fixed cT3 stage primary rectal adenocarcinoma. The distant recurrence rate may not be altered by consolidation chemotherapy in the subset of high-risk patients. However, further research on consolidation chemotherapy following NACRT in cT4 and fixed cT3 stage primary rectal adenocarcinoma will give a definite answer in the future.

SOX9 is associated with advanced T-stages of clinical stage II colon cancer in young Mexican patients

Colorectal cancer (CRC) is one of the most common malignancies worldwide and includes colon cancer (CC) and rectal cancer (RC). Regarding CC, the development of novel molecular biomarkers for the accurate diagnosis and prognosis, as well as the identification of novel targets for therapeutic intervention, are urgently needed. SRY-related high-mobility group box 9 (SOX9), a transcription factor, is involved in development, and has been associated with the progression of human cancer. However, its underlying clinical and functional effects in CRC have not been fully understood. Therefore, the present study aimed to evaluate the clinical and functional relevance of SOX9 expression in CC. The expression of SOX9 in tumor tissues was evaluated in 97 biopsies from Mexican patients with CC with early-stage I and II disease by immunohistochemistry (IHC). In addition, SOX9 silencing in the HCT116 cell line was performed using specific small interfering RNAs, while downregulation efficiency was verified by reverse transcription-quantitative PCR and immunofluorescence. Spheroid-formation assay was carried out using ultra-low attachment plates. The IHC results showed that SOX9 was upregulated in patients with stage II (91%) and advanced T3 stage (67%) CC. Interestingly, higher SOX9 expression was associated with clinical stage, tumor size and tumor location. Furthermore, increased SOX9 expression was found in relapsed cases with local tumors; however, it was not associated with increased survival probability. Additionally, functional analysis indicated that SOX9 silencing significantly attenuated the sphere-formation capability of HCT116 cells. The present study was the first to evaluate the expression levels of SOX9 in Mexican patients diagnosed with early-stage CC. The aforementioned findings indicated that high SOX9 expression could play an important role in tumorigenesis and be associated with advanced T-stages of clinical-stage II patients, but not with relapse-free survival.

Tumor Long Interspersed Nucleotide Element-1 (LINE-1) Hypomethylation in Relation to Age of Colorectal Cancer Diagnosis and Prognosis

Evidence indicates the pathogenic role of epigenetic alterations in early-onset colorectal cancers diagnosed before age 50. However, features of colorectal cancers diagnosed at age 50-54 (hereafter referred to as "intermediate-onset") remain less known. We hypothesized that tumor long interspersed nucleotide element-1 (LINE-1) hypomethylation might be increasingly more common with decreasing age of colorectal cancer diagnosis. In 1356 colorectal cancers, including 28 early-onset and 66 intermediate-onset cases, the tumor LINE-1 methylation level measured by bisulfite-PCR-pyrosequencing (scaled 0 to 100) showed a mean of 63.6 (standard deviation (SD) 10.1). The mean tumor LINE-1 methylation level decreased with decreasing age (mean 64.7 (SD 10.4) in age ≥70, 62.8 (SD 9.4) in age 55-69, 61.0 (SD 10.2) in age 50-54, and 58.9 (SD 12.0) in age <50; p < 0.0001). In linear regression analysis, the multivariable-adjusted β coefficient (95% confidence interval (CI)) (vs. age ≥70) was -1.38 (-2.47 to -0.30) for age 55-69, -2.82 (-5.29 to -0.34) for age 50-54, and -4.54 (-8.24 to -0.85) for age <50 (Ptrend = 0.0003). Multivariable-adjusted hazard ratios (95% CI) for LINE-1 methylation levels of ≤45, 45-55, and 55-65 (vs. >65) were 2.33 (1.49-3.64), 1.39 (1.05-1.85), and 1.29 (1.02-1.63), respectively (Ptrend = 0.0005). In conclusion, tumor LINE-1 hypomethylation is increasingly more common with decreasing age of colorectal cancer diagnosis, suggesting a role of global DNA hypomethylation in colorectal cancer arising in younger adults.

Whole genome transcriptome analysis of the stomach resected in human vertical sleeve gastrectomy: cutting more than calories

Vertical sleeve gastrectomy (VSG) is a surgical weight loss procedure that resects 80% of the stomach, creating a tube linking the esophagus to the duodenum. Because of the efficacy and relative simplicity of VSG, it is preferred in the United States, with VSG currently at >61% of bariatric surgeries performed. Surprisingly, there has never been a complete molecular characterization of the human stomach greater curvature's fundus and corpus. Here we compare and contrast the molecular makeup of these regions. We performed a prospective cohort study to obtain gastric tissue samples from patients undergoing elective VSG. Paired fundus and corpus samples were obtained. Whole genome transcriptome analysis was performed by RNA sequencing (N = 10), with key findings validated by qPCR (N = 24). Participants were primarily female (95.8%) and White (79.15%). Mean body mass index, body weight, and age were 46.1 kg/m², 121.6 kg, and 43.29 yr, respectively. Overall, 432 gene transcripts were significantly different between the fundus and the corpus (P < 0.05). A significant correlation was found between the RNA sequencing dataset and qPCR validation, demonstrating robust gene expression differences between the fundus and the corpus. Significant genes included progastricsin, acidic chitinase, and gastokine 1 and 2 in both the fundus and the corpus. Of the very highly expressed genes in both regions, 87% were present in both the stomach's fundus and corpus, indicating substantial overlap. Despite significant overlap in the greater curvature gene signature, regional differences exist within the fundus and the corpus. Given that the mechanism of VSG is partly unresolved, the potential that the resected tissue may express genes that influence long-term body weight regulation is unknown and could influence VSG outcomes.

Fluoropyrimdine therapy induced alterations in interleukins expression in colorectal cancer patients

This study monitored the changes in the expression of inflammatory IL-6 and IL-1β during the treatment period of Fluoropyrimidine (FP) based therapy. RNA was extracted from the peripheral blood of 102 CRC patients before treatment with FP therapy, and from 48 and 32 patients after 3 and 6 months of treatment, respectively. The genetic transcription of IL-6 and IL-1β was determined by real time PCR. Patients were stratified according to their levels of IL-6 and IL-1β genes expression for subgroup and survival analyses. Baseline CRC patients showed overexpression of IL-6 and IL-1β compared to healthy control. FP therapy significantly induced IL-6 and IL-1β expression. Subgroup analysis showed that patients with right colon tumors had significant elevation in both IL-6 and IL-1β with FP therapy. FP therapy significantly induced IL-1β expression in patients ⩽45 years, smokers, with high baseline level of CA19.9, right colon tumors, low grade pathology, T3 tumors and positive lymph nodes. Survival analysis showed that baseline levels of interleukins expression had insignificant effect on overall survival and event free survival. FP therapy has an impact on the level of interleukins expression declared in certain clinicopathological subgroups of CRC patients, but without a prognostic significance on patients' survival.

LncRNA signature in colorectal cancer

Colorectal cancer (CRC) is among the most frequent cancers and is associated with high mortality particularly when being diagnosed in advanced stages. Although several environmental and intrinsic risk factors have been identified, the underlying cause of CRC is not clear in the majority of cases. Several studies especially in the recent decade have pointed to the role of epigenetic factors in this kind of cancer. Long non-coding RNAs (lncRNAs) as important contributors in the epigenetic mechanisms are involved in the initiation, progression and metastasis of CRC. Tens of oncogenic lncRNAs and a lower number of tumor suppressor lncRNAs have been recently identified to be dysregulated in CRC cells and tissues. Notably, expressions of a number of these transcripts have been dysregulated in serum samples of CRC patients, providing a non-invasive route for detection of this kind of cancer. The involvement of lncRNAs in the regulation of autophagy has provided them the ability to modulate response of CRC cells to chemotherapeutic modalities. In the current manuscript, we review the studies which evaluated the role of lncRNAs in the pathogenesis and progression of CRC to appraise their application as diagnostic/ prognostic markers.

Association Between Obesity and Histological Tumor Budding in Patients With Nonmetastatic Colon Cancer

IMPORTANCE

Obesity is associated with increased risk of colorectal cancer (CRC) and a more aggressive disease course. Tumor budding (TB) is an important prognostic factor for CRC, but its association with obesity is unknown.

OBJECTIVE

To evaluate the association of TB with obesity and other prognostic factors in colon cancer.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study involved a histological review of colon cancer specimens obtained during 7 years (January 2008 to December 2015) at the University of Kentucky Medical Center; data analysis was conducted from February 2020 to January 2021. Specimens came from 200 patients with stage I to III colon cancer; patients with stage 0, stage IV, or incomplete data were excluded.

MAIN OUTCOMES AND MEASURES

TB was defined as 1 to 4 malignant cells at the invasive edge of the tumor, independently assessed by 2 academic pathologists. The primary outcome was the association of TB with obesity (defined as body mass index [BMI] of 30 or greater). Secondary outcomes include the association of TB with clinical features (ie, age, race, sex, TNM stage, tumor location) and pathological features (ie, poorly differentiated tumor clusters [PDCs], Klintrup-Mäkinen inflammatory score, desmoplasia, infiltrative tumor border, tumor necrosis, and tumor-to-stroma ratio).

RESULTS

A total of 200 specimens were reviewed. The median (interquartile range) age of patients was 62 (55-72) years, 102 (51.0%) were women, and the mean (SD) BMI was 28.5 (8.4). A total of 57 specimens (28.5%) were from stage I tumors; 74 (37.0%), stage II; and 69 (34.5%), stage III. Of these, 97 (48.5%) had low-grade (<5 buds), 36 (18.0%) had intermediate-grade (5-9 buds), and 67 (33.5%) had high-grade (≥10 buds) TB. Multivariable analysis adjusting for clinical and histological factors demonstrated that higher TB grade was associated with obesity (odds ratio [OR], 4.25; 95% CI, 1.95-9.26), higher PDC grade (grade 2 vs 1: OR, 9.14; 95% CI, 3.49-23.93; grade 3 vs 1: OR, 5.10; 95% CI, 2.30-11.27), increased infiltrative tumor border (OR, 1.03; 95% CI, 1.01-1.04), cecal location (OR, 2.55; 95% CI, 1.09-5.97), and higher stage (eg, stage III vs stage I for high-grade or intermediate-grade vs low-grade TB: OR, 2.91; 95% CI, 1.00-8.49). Additionally, patients with a higher TB grade had worse overall survival (intermediate vs low TB: hazard ratio, 2.20; 95% CI, 1.11-4.35; log-rank P = .02; high vs low TB: hazard ratio, 2.67; 95% CI, 1.45-4.90; log-rank P < .001).

CONCLUSIONS AND RELEVANCE

In this cohort study, a novel association between high TB grade and obesity was found. The association could reflect a systemic condition (ie, obesity) locally influencing aggressive growth (ie, high TB) in colon cancer.

Systematic Review of Prevalence, Risk Factors, and Risk for Metachronous Advanced Neoplasia in Patients With Young-Onset Colorectal Adenoma

BACKGROUND & AIMS

The incidence and mortality of early-onset colorectal cancer (CRC) are increasing. Adenoma detection, removal, and subsequent endoscopic surveillance might modify risk of CRC diagnosed before age 50 years (early-onset CRC). We conducted a systematic review of young-onset adenoma (YOA) prevalence, associated risk factors, and rate of metachronous advanced neoplasia after YOA diagnosis.

METHODS

We performed a systematic search of multiple electronic databases through February 12, 2019 and identified studies of individuals 18 to 49 years old that reported prevalence of adenoma, risk factors for adenoma, and/or risk for metachronous advanced neoplasia. Summary estimates were derived using random effects meta-analysis, when feasible.

RESULTS

The pooled overall prevalence of YOA was 9.0% (95% CI, 7.1%-11.4%), based on 24 studies comprising 23,142 individuals. On subgroup analysis, the pooled prevalence of YOA from autopsy studies was 3.9% (95% CI, 1.9%-7.6%), whereas the prevalence from colonoscopy studies was 10.7% (95% CI, 8.5%-13.5). Only advancing age was identified as a consistent risk factor for YOA, based on 4 studies comprising 78,880 individuals. Pooled rate of metachronous advanced neoplasia after baseline YOA diagnosis was 6.0% (95% CI, 4.1%-8.6%), based on 3 studies comprising 1493 individuals undergoing follow-up colonoscopy, with only 1 CRC case reported. Overall, few studies reported metachronous advanced neoplasia and no studies evaluated whether routine surveillance colonoscopy decreases risk of CRC.

CONCLUSIONS

In a systematic review, we estimated the prevalence of YOA to be 9% and to increase with age. Risk for metachronous advanced neoplasia after YOA diagnosis is estimated to be 6%. More research is needed to understand the prevalence, risk factors, and risk of CRC associated with YOA.

Rising incidence of early-onset colorectal cancer - a call to action

The incidence of early-onset colorectal cancer (CRC), which occurs in individuals <50 years of age, has been increasing worldwide and particularly in high-income countries. The reasons for this increase remain unknown but plausible hypotheses include greater exposure to potential risk factors, such as a Western-style diet, obesity, physical inactivity and antibiotic use, especially during the early prenatal to adolescent periods of life. These exposures can not only cause genetic and epigenetic alterations in colorectal epithelial cells but also affect the gut microbiota and host immunity. Early-onset CRCs have differential clinical, pathological and molecular features compared with later-onset CRCs. Certain existing resources can be utilized to elucidate the aetiology of early-onset CRC and inform the development of effective prevention, early detection and therapeutic strategies; however, additional life-course cohort studies spanning childhood and young adulthood, integrated with prospective biospecimen collections, omics biomarker analyses and a molecular pathological epidemiology approach, are needed to better understand and manage this disease entity. In this Perspective, we summarize our current understanding of early-onset CRC and discuss how we should strategize future research to improve its prevention and clinical management.

Age disparities in stage-specific colon cancer survival across seven countries: An International Cancer Benchmarking Partnership SURVMARK-2 population-based study

We sought to understand the role of stage at diagnosis in observed age disparities in colon cancer survival among people aged 50 to 99 years using population-based cancer registry data from seven high-income countries: Australia, Canada, Denmark, Ireland, New Zealand, Norway and the United Kingdom. We used colon cancer incidence data for the period 2010 to 2014. We estimated the 3-year net survival, as well as the 3-year net survival conditional on surviving at least 6 months and 1 year after diagnosis, by country and stage at diagnosis (categorised as localised, regional or distant) using flexible parametric excess hazard regression models. In all countries, increasing age was associated with lower net survival. For example, 3-year net survival (95% confidence interval) was 81% (80-82) for 50 to 64 year olds and 58% (56-60) for 85 to 99 year olds in Australia, and 74% (73-74) and 39% (39-40) in the United Kingdom, respectively. Those with distant stage colon cancer had the largest difference in colon cancer survival between the youngest and the oldest patients. Excess mortality for the oldest patients with localised or regional cancers was observed during the first 6 months after diagnosis. Older patients diagnosed with localised (and in some countries regional) stage colon cancer who survived 6 months after diagnosis experienced the same survival as their younger counterparts. Further studies examining other prognostic clinical factors such as comorbidities and treatment, and socioeconomic factors are warranted to gain further understanding of the age disparities in colon cancer survival.

Development of a dual-energy spectral computed tomography-based nomogram for the preoperative discrimination of histological grade in colorectal adenocarcinoma patients

Background

The usefulness of a dual-energy spectral computed tomography (DESCT)-based nomogram in discriminating between histological grades of colorectal adenocarcinoma (CRAC) is unclear. This study aimed to develop such a nomogram and assess its ability to preoperatively discriminate between histological grades in CRAC patients.

Methods

Primary tumors monochromatic CT value, iodine concentration (IC) value, and effective atomic number (Eff-Z) in the arterial (AP) and venous phases (VP) were retrospectively compared between patients with high-grade (n=65) and low-grade (n=108) CRAC who underwent preoperative abdominal DESCT. Univariate analysis was used to compare the DESCT parameters and clinical factors between these two patient groups. Statistically significant features in the univariate analysis were included in the multivariate logistic regression model to identify the indicators for building a nomogram that could discriminate between histological grades in CRAC patients. The clinical usefulness of the nomogram and its value for predicting overall survival were statistically evaluated.

Results

The logistic regression analysis showed that age, clinical T stage, clinical N stage, and IC values in AP and VP were significant independent predictors for high-grade CRAC. A quantitative nomogram developed based on these predictors showed excellent performance for discriminating between the histological grades, with an area under the curve (AUC) of 0.886 and excellent agreement in the calibration curve. The Kaplan-Meier curve for overall survival showed that our nomogram identified a significant difference between the high- and low-risk groups [hazard ratio (HR), 2.188; 95% CI, 1.072-4.465; P=0.027).

Conclusions

This study presents a nomogram that incorporates DESCT parameters and clinical factors and can potentially be used as a clinical tool for individual preoperative prediction of CRAC histological grade.

Prospective evaluation of dietary and lifestyle pattern indices with risk of colorectal cancer in a cohort of younger women

BACKGROUND

Although colorectal cancer (CRC) incidence in the USA is declining overall, its incidence is increasing among those younger than 50 years of age. The reasons underlying the increasing trend are largely unknown, although behavioral changes, such as unhealthy diet and lifestyle factors, may be partially responsible.

DESIGN

A prospective cohort study included 94 217 women aged 26-45 years at baseline. Validated anthropometric measures and lifestyle information were self-reported biennially. Exposures were four recommendation-based dietary indices-the prime diet quality score and three plant-based dietary indices; and two mechanism-based indices-the empirical dietary and lifestyle index for hyperinsulinemia (EDIH and ELIH). We calculated hazard ratios (HRs) and 95% confidence intervals (CIs) for overall CRC and for early-onset (before age 50) and after age 50 CRC separately.

RESULTS

We documented 332 cases of CRC during 24 years of follow-up (2 113 655 person-years), with an average age of 52 ± 7 years at diagnosis. Hyperinsulinemic dietary and lifestyle patterns were associated with a higher risk of CRC. Multivariable-adjusted HRs (95% CIs) comparing participants in the highest versus lowest quartile were: 1.67 for EDIH (95% CI: 1.15-2.44, P-trend = 0.01) and 1.51 for ELIH (95% CI: 1.10-2.08, P-trend = 0.01). Moreover, per 75% increment in rank, ELIH appeared to be a stronger risk factor for early-onset CRC (HR = 1.86, 95% CI: 1.12-3.07) than after age 50 CRC (HR = 1.20, 95% CI: 0.83-1.73, P-heterogeneity = 0.16). The four recommendation-based indices were not significantly associated with overall, early-onset, or after age 50 CRC risk (per 75% increment in rank, HRs ranged from 0.75 to 1.28).

CONCLUSION

Dietary and lifestyle patterns contributing to hyperinsulinemia were associated with greater CRC risk in younger women. Moreover, the hyperinsulinemic lifestyle showed a suggestively stronger positive association with early-onset CRC risk, compared with after age 50 CRC. Our findings suggest that dietary and lifestyle interventions to reduce insulinemic potential may be effective for CRC prevention among younger women.

Modeling colorectal cancers using multidimensional organoids

Organoids have revolutionized cancer research as highly adaptable models that enable an array of experimental techniques to interrogate tissue morphology and function. Because they preserve the genetic, phenotypic, and behavioral traits of their source tissue, organoids have gained traction as the most relevant models for drug discovery, tracking therapeutic response and for personalized medicine. As organoids are indisputably becoming a mainstay of cancer research, this review specifically addresses how colon-derived organoids can be perfected as multidimensional, scalable, reproducible models of healthy, pre-neoplastic and neoplastic conditions of the colon and for use in high-throughput "Phase-0" human clinical trials-in-a-dish.

Clinical, Pathological and Molecular Characteristics of Chilean Patients with Early-, Intermediate- and Late-Onset Colorectal Cancer

Colorectal cancer (CRC) is the second most frequent neoplasm in Chile and its mortality rate is rising in all ages. However, studies characterizing CRC according to the age of onset are still lacking. This study aimed to identify clinical, pathological, and molecular features of CRC in Chilean patients according to the age of diagnosis: early- (≤50 years; EOCRC), intermediate- (51–69 years; IOCRC), and late-onset (≥70 years; LOCRC). The study included 426 CRC patients from Clinica Las Condes, between 2007 and 2019. A chi-square test was applied to explore associations between age of onset and clinicopathological characteristics. Body Mass Index (BMI) differences according to age of diagnosis was evaluated through t-test. Overall (OS) and cancer-specific survival (CSS) were estimated by the Kaplan–Meier method. We found significant differences between the age of onset, and gender, BMI, family history of cancer, TNM Classification of Malignant Tumors stage, OS, and CSS. EOCRC category was characterized by a family history of cancer, left-sided tumors with a more advanced stage of the disease but better survival at 10 years, and lower microsatellite instability (MSI), with predominant germline mutations. IOCRC has shown clinical similarities with the EOCRC and molecular similarities to the LOCRC, which agrees with other reports.

An Update on the Epidemiology, Molecular Characterization, Diagnosis, and Screening Strategies for Early-Onset Colorectal Cancer

Rising trends in the incidence and mortality of early-onset colorectal cancer (CRC) in those who are younger than 50 years have been well established. These trends have spurred intense investigation focused on elucidating the epidemiology and characteristics of early-onset CRC, as well as on identifying strategies for early detection and prevention. In this review, we provide a contemporary update on early-onset CRC with a particular focus on epidemiology, molecular characterization, red flag signs and symptoms, and screening for early-onset CRC.

Emerging trends in colorectal cancer: Dysregulated signaling pathways (Review)

Colorectal cancer (CRC) is the third most frequently detected type of cancer, and the second most common cause of cancer‑related mortality globally. The American Cancer Society predicted that approximately 147,950 individuals would be diagnosed with CRC, out of which 53,200 individuals would succumb to the disease in the USA alone in 2020. CRC‑related mortality ranks third among both males and females in the USA. CRC arises from 3 major pathways: i) The adenoma‑carcinoma sequence; ii) serrated pathway; and iii) the inflammatory pathway. The majority of cases of CRC are sporadic and result from risk factors, such as a sedentary lifestyle, obesity, processed diets, alcohol consumption and smoking. CRC is also a common preventable cancer. With widespread CRC screening, the incidence and mortality from CRC have decreased in developed countries. However, over the past few decades, CRC cases and mortality have been on the rise in young adults (age, <50 years). In addition, CRC cases are increasing in developing countries with a low gross domestic product (GDP) due to lifestyle changes. CRC is an etiologically heterogeneous disease classified by tumor location and alterations in global gene expression. Accumulating genetic and epigenetic perturbations and aberrations over time in tumor suppressor genes, oncogenes and DNA mismatch repair genes could be a precursor to the onset of colorectal cancer. CRC can be divided as sporadic, familial, and inherited depending on the origin of the mutation. Germline mutations in APC and MLH1 have been proven to play an etiological role, resulting in the predisposition of individuals to CRC. Genetic alterations cause the dysregulation of signaling pathways leading to drug resistance, the inhibition of apoptosis and the induction of proliferation, invasion and migration, resulting in CRC development and metastasis. Timely detection and effective precision therapies based on the present knowledge of CRC is essential for successful treatment and patient survival. The present review presents the CRC incidence, risk factors, dysregulated signaling pathways and targeted therapies.

Racial disparities and treatment trends among young-onset colorectal cancer patients: An analysis of a hospital cancer registry

BACKGROUND

There is an increasing trend of colorectal cancer (CRC) incidence and mortality in individuals under the age of 50. The impact of age on the outcomes of CRC remains controversial. This study examined the characteristics and treatment trends of young-onset CRC by comparing patients < 50 years of age to those ≥50.

METHODS

Data were retrospectively obtained from one of the largest hospital systems in Virginia. The sample included patients diagnosed with CRC from 2008 to 2016. Bivariate analyses were used to describe patients' characteristics. Stratified and multivariate analyses were used to evaluate the association between treatments and age groups in different stages at diagnosis.

RESULTS

Approximately 11.6 % (n = 522) of the cohort were younger than 50 years old at diagnosis with a mean age of 42.7 (SD = 5.9) years. Compared to their older counterpart (50 and older), young-onset patients were more likely to be African American (28.7 % (n = 150) vs. 23.7 % (n = 944)), to own private insurance (68.5 % (n = 313) vs. 27.6 % (n = 1032)), to have never used tobacco products (50.4 % (n = 237) vs. 43.8 % (n = 1616)), and to be late stage at diagnosis (68.6 % (n = 358) vs. 52.5 % (n = 2090)) (all p < 0.05). For early stage diagnosis, over 98 % of the young-onset treatments were surgery. For late stage diagnosis, the cancer treatment for young onset patients were a combination of surgery (89.4 %), radiation (82.5 %), and chemotherapy (86.3 %). The results of the analyses also demonstrated that patients with young-onset CRC have higher odds for surgery [OR = 1.76, 95 %CI (1.26, 2.47)], radiation [OR = 1.31, 95 %CI (1.17, 1.47)], and chemotherapy [OR = 3.34, 95 %CI (2.62, 4.25)].

CONCLUSIONS

Findings confirmed late-stage prevalence among young-onset as well as significant demographic differences with patients' age ≥50. This study is one of few to explore the characteristics and assess treatment of young patients with CRC using U.S hospital data. Moreover, further studies need to clarify the effects of biological properties like genetic influences and environmental factors between races on cancer patient outcomes.

Predictive value of initial imaging and staging with long-term outcomes in young adults diagnosed with colorectal cancer

PURPOSE

To evaluate how initial abdominopelvic CT findings and staging correlate with outcomes in a cohort of patients aged 18-40 years.

METHODS

We evaluated all young adult patients at a single tertiary center diagnosed with histopathologically confirmed CRC who also had CT of the abdomen and pelvis at the time of initial diagnosis. Demographics, symptoms, CT findings, staging, treatments, and outcomes at 1 year and 5 years were recorded.

RESULTS

Of 91 patients who met initial inclusion criteria, 81.8% had a mass present on CT, with an average size of 4.8 cm ± 2.9. A majority of patients were surgical stage III or IV (64.3%). Advanced AJCC stage was more common with rectal tumors and metastatic disease on initial CT (p < 0.0001). In a subgroup analysis, almost all patients initially staged 4A or higher had progression of disease. At the final follow-up visit, by RECIST 1.1 criteria, 58.8% had progressive disease, 35.3% complete response, and 3.9% stable disease. The overall 5-year survival rate in this subgroup was 40% with lower survival probability with increasing stage (p = 0.0001).

CONCLUSION

Most young adult patients presented with large tumors on imaging, increasing the likelihood of identification on CT. Tumors initially presenting in the rectum with enlarged lymph nodes and/or with distant metastases on CT were more often associated with advanced surgical stage and poorer prognosis. A majority of patients presented at an advanced stage, most commonly stage 4A, and had progression of disease at follow-up.

Colorectal cancer of the young displays distinct features of aggressive tumor biology: A single-center cohort study

BACKGROUND

In recent years, a decrease in incidence and mortality of colorectal cancer (CRC) has been observed in developed nations, presumably through public disease awareness and increased screening efforts. However, a rising incidence of CRC in young patients below the age of 50 years has been reported in several studies.

AIM

To study tumor biology in CRC patients below 50 years of age.

METHODS

All patients with CRC were prospectively enrolled in our single-center oncologic database from January 2013 to December 2018 and were grouped and analyzed according to age (≥ 50 and < 50 years). Clinical as well as histopathological features were analyzed and compared. The study was approved by the local Ethics Committee. Fisher’s exact test or t-test was used to test for differences between the groups, as appropriate. All statistical analysis was performed with IBM SPSS software Version 25 (SPSS Inc, Armonk, NY, United States) and with R-Studio using R Version 3.4.1 (RStudio, Boston, MA, United States).

RESULTS

Seventeen percent of the 411 patients were younger than 50 years. Young patients were more often diagnosed with locally advanced T4-tumors and lymph node metastases (36.6% and 62% vs 17.7% and 42%; P < 0.01). In addition, a higher frequency of poorly differentiated (G3) tumors (40% vs 22.4% P < 0.05) was observed. More than every second patient below 40 years of age (51.8%) had distant metastases at diagnosis with a significant higher rate ring of signet cell differentiation compared to patients ≥ 50 years (14.8%, P < 0.05). Mutational status (KRAS, NRAS, BRAF, MSI) as well as selected behavioral risk factors showed no significant differences.

CONCLUSION

Distinct histopathologic features of increased biologic aggressiveness are found in patients with CRC of young-onset. Those patients present more frequently with more advanced tumor stages compared to older patients. Features of aggressive tumor biology underscore the need for earlier uptake of routine screening measures.

Synergistic potential of dual andrographolide and melatonin targeting of metastatic colon cancer cells: Using the Chou-Talalay combination index method

Colorectal cancer (CRC) mortality has diminished for decades due to new and improved treatment profiles. However, CRC still ranks as the third most diagnosed cancer in the US. Therefore, a new therapeutic approach is needed to overcome colospheroids inhibition and drug resistance. It is well documented that andrographolide (AGP) and melatonin (MLT) have anti-carcinogenic properties. Our goal was to evaluate their synergistic effects on metastatic colon cancer cells (mCRC) and colospheroids. HT-29 and HCT-15 mCRC cells were simultaneously treated with serial dilutions of AGP and MLT for 24, 48 and 72 h. Cell viability was monitored using the MTT assay. The Chou-Talalay method for drug combination is based on the median effect equation, providing a theoretical basis for the combination index and the isobologram equation. This allows quantitative determination of drug interactions using the CompuSyn software, where CI < 1, = 1, and >1 indicates synergistic, additive, and antagonistic effects respectively. Our results demonstrate that AGP and MLT in combination show synergism with CI values of 0.35293 and 0.34152 for HT-29 and HCT-15 respectively and a fractional inhibition of Fa = 0.50-0.90, as shown by the Fa-CI plot and isobologram. The synergism value was validated in colospheroids (HT-29-s and HCT-15-s) based on morphology, viability, and colony formation and in 5-FU drug resistant cell (HT-29R and HCT-116R) viability. The mechanism(s) of decreased cell viability are due to the induction of ER stress proteins and angiogenic inhibition. Our results provide rationale for using AGP in combination with MLT on mCRC.

Real-World Long-Term Outcomes with Perioperative EOX in D2 Gastrectomy: a Meaningful Look While We Switch to FLOT-4

INTRODUCTION

Data regarding long-term survival and prognosis in loco-regionally advanced, non-metastatic gastric cancers (GC) using perioperative chemotherapy and D2 lymphadenectomies from India is scarce.

MATERIALS AND METHODS

The study is a retrospective evaluation of locally advanced gastric cancers who received epirubicin-oxaliplatin-capecitabine (EOX) as perioperative therapy from May 2013 to December 2015 at Tata Memorial Hospital, Mumbai. The report concentrates on long-term survival outcomes and prognostic factors. Event-free survival (EFS) and overall survival (OS) were calculated using Kaplan-Meier method.

RESULTS

Two hundred and sixty-eight patients were started on EOX regimen, of which 200 patients (74.6%) underwent definitive resection with D2 lymphadenectomy. With a median follow-up of 52.7 months, the estimated median 3-year and 5-year EFS were 38.5% and 36.3% respectively. The estimated median 3-year and 5-year OS were 41.7% and 37.6% respectively. Patients younger than age 40 years [HR 1.55 (1.034-2.321); p = 0.034] and with poorly differentiated histology [HR 0.65 (0.446-0.944); p = 0.024] had inferior OS compared to their counterparts.

CONCLUSIONS

Long-term OS in Indian patients in non-metastatic GC with EOX chemotherapy and D2 lymphadenectomy is similar to previously published Western data. Younger Indian patients fare worse than their older counterparts and this needs further evaluation.

Dendritic cell vaccine therapy for colorectal cancer

Colorectal cancer (CRC) remains a leading cause of cancer-related deaths in the United States despite an array of available treatment options. Current standard-of-care interventions for this malignancy include surgical resection, chemotherapy, and targeted therapies depending on the disease stage. Specifically, infusion of anti-vascular endothelial growth factor agents in combination with chemotherapy was an important development in improving the survival of patients with advanced colorectal cancer, while also helping give rise to other forms of anti-angiogenic therapies. Yet, one approach by which tumor angiogenesis may be further disrupted is through the administration of a dendritic cell (DC) vaccine targeting tumor-derived blood vessels, leading to cytotoxic immune responses that decrease tumor growth and synergize with other systemic therapies. Early generations of such vaccines exhibited protection against various forms of cancer in pre-clinical models, but clinical results have historically been disappointing. Sipuleucel-T (Provenge®) was the first, and to-date, only dendritic cell-based therapy to receive FDA approval after significantly increasing overall survival in prostate cancer patients. The unparalleled success of Sipuleucel-T has helped revitalize the clinical development of dendritic cell vaccines, which will be examined in this review. We also highlight the promise of these vaccines to instill anti-angiogenic immunity for individuals with advanced colorectal cancer.

Contributions of Adenocarcinoma and Carcinoid Tumors to Early-Onset Colorectal Cancer Incidence Rates in the United States

BACKGROUND

Early-onset colorectal cancer (EOCRC) incidence rates (IRs) are rising, according to previous cancer registry analyses. However, analysis of histologic subtypes, including adenocarcinoma (the focus of CRC screening and diagnostic testing) and carcinoid tumors (which are classified as "colorectal cancer" in SEER [Surveillance, Epidemiology, and End Results] databases but have a distinct pathogenesis and are managed differently from adenocarcinoma), has not been reported.

OBJECTIVE

To assess EOCRC IRs and changes in IRs over time, stratified by histology.

DESIGN

Retrospective analysis.

SETTING

Yearly IRs according to SEER 18 data from 2000 to 2016 on age-specific colon-only, rectal-only, and combined-site CRC cases, stratified by histology ("overall" CRC [all histologic subtypes], adenocarcinoma, and carcinoid tumors) and age.

PATIENTS

119 624 patients with CRC.

MEASUREMENTS

IRs per 100 000 population, changes in 3-year average annual IRs (pooled IRs from 2000 to 2002 vs. those from 2014 to 2016), and annual percentage change (APC) in persons aged 20 to 29, 30 to 39, 40 to 49, and 50 to 54 years.

RESULTS

The steepest changes in adenocarcinoma 3-year average annual IRs were for rectal-only cases in persons aged 20 to 29 years (+39% [0.33 to 0.46 per 100 000]; P < 0.050) and 30 to 39 years (+39% [1.92 to 2.66 per 100 000]; P < 0.050) and colon-only cases in those aged 30 to 39 years (+20% [3.30 to 3.97 per 100 000]; P < 0.050). Corresponding APCs were 1.6% (P < 0.050), 2.2% (P < 0.050), and 1.2% (P < 0.050), respectively. In persons aged 40 to 49 years, 3-year average annual IRs increased in both colon-only (+13% [12.21 to 13.85 per 100 000]; P < 0.050) and rectal-only (+16% [7.50 to 8.72 per 100 000]; P < 0.050) subsites. Carcinoid tumors were common, representing approximately 4% to 20% of all colorectal and 8% to 34% of all rectal cancer cases, depending on age group and calendar year. Colon-only carcinoid tumors were rare. Colorectal carcinoid tumor IRs increased more steeply than adenocarcinoma in all age groups, thus affecting the contribution of carcinoid tumors to overall cancer cases over time. These changes were driven by rectal subsites and were most pronounced in persons aged 50 to 54 years, in whom rectal carcinoid tumors increased by 159% (2.36 to 6.10 per 100 000) between 2000 to 2002 and 2014 to 2016, compared with 10% for adenocarcinoma (18.07 to 19.84 per 100 000), ultimately accounting for 22.6% of all rectal cancer cases.

LIMITATION

Population-based data.

CONCLUSION

These findings underscore the importance of assessing histologic CRC subtypes independently. Doing so may lead to a better understanding of the drivers of temporal changes in overall CRC incidence and a more accurate measurement of outcomes from efforts to reduce adenocarcinoma risk, and can guide future research.

PRIMARY FUNDING SOURCE

None.

The clinical features, management, and survival of elderly patients with colorectal cancer

Background

As the population ages, the number of elderly patients with colorectal cancer is increasing year by year. However, older people have rarely been the focus of studies on colorectal cancer. Therefore, in the present study, we aimed to carry out a retrospective analysis of this patient subgroup.

Methods

A retrospective study of clinical data of patients aged over 80 years who died from colorectal cancer in our hospital between 1993 and 2020 was performed. Logistic regression, the Kaplan-Meier method, and a multivariate Cox proportional hazards model were used to analyze the overall survival and treatment outcomes of the patients.

Results

A total of 87 patients were included in the study. The overall median survival was 45 months. In most patients, the primary lesion was located in the right colon. One-quarter of the patients refused to accept any treatment. Patients with stage IV tumors, who accounted for the largest proportion of the study population, displayed a higher rate of abandoning treatment than did patients of other stages. Almost all patients with stages II and III accepted surgery. Patients who underwent surgery to treat their colorectal cancer had longer survival than those who did not.

Conclusions

Old age should not be a reason for giving up treatment for colorectal cancer. The treatment of colorectal cancer patients aged 80 years and above requires individualized evaluation and more aggressive treatment to achieve greater benefits.

Adiposity, metabolites, and colorectal cancer risk: Mendelian randomization study

BACKGROUND

Higher adiposity increases the risk of colorectal cancer (CRC), but whether this relationship varies by anatomical sub-site or by sex is unclear. Further, the metabolic alterations mediating the effects of adiposity on CRC are not fully understood.

METHODS

We examined sex- and site-specific associations of adiposity with CRC risk and whether adiposity-associated metabolites explain the associations of adiposity with CRC. Genetic variants from genome-wide association studies of body mass index (BMI) and waist-to-hip ratio (WHR, unadjusted for BMI; N = 806,810), and 123 metabolites from targeted nuclear magnetic resonance metabolomics (N = 24,925), were used as instruments. Sex-combined and sex-specific Mendelian randomization (MR) was conducted for BMI and WHR with CRC risk (58,221 cases and 67,694 controls in the Genetics and Epidemiology of Colorectal Cancer Consortium, Colorectal Cancer Transdisciplinary Study, and Colon Cancer Family Registry). Sex-combined MR was conducted for BMI and WHR with metabolites, for metabolites with CRC, and for BMI and WHR with CRC adjusted for metabolite classes in multivariable models.

RESULTS

In sex-specific MR analyses, higher BMI (per 4.2 kg/m2) was associated with 1.23 (95% confidence interval (CI) = 1.08, 1.38) times higher CRC odds among men (inverse-variance-weighted (IVW) model); among women, higher BMI (per 5.2 kg/m2) was associated with 1.09 (95% CI = 0.97, 1.22) times higher CRC odds. WHR (per 0.07 higher) was more strongly associated with CRC risk among women (IVW OR = 1.25, 95% CI = 1.08, 1.43) than men (IVW OR = 1.05, 95% CI = 0.81, 1.36). BMI or WHR was associated with 104/123 metabolites at false discovery rate-corrected P ≤ 0.05; several metabolites were associated with CRC, but not in directions that were consistent with the mediation of positive adiposity-CRC relations. In multivariable MR analyses, associations of BMI and WHR with CRC were not attenuated following adjustment for representative metabolite classes, e.g., the univariable IVW OR for BMI with CRC was 1.12 (95% CI = 1.00, 1.26), and this became 1.11 (95% CI = 0.99, 1.26) when adjusting for cholesterol in low-density lipoprotein particles.

CONCLUSIONS

Our results suggest that higher BMI more greatly raises CRC risk among men, whereas higher WHR more greatly raises CRC risk among women. Adiposity was associated with numerous metabolic alterations, but none of these explained associations between adiposity and CRC. More detailed metabolomic measures are likely needed to clarify the mechanistic pathways.

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.

Organoid cultures of early-onset colorectal cancers reveal distinct and rare genetic profiles

OBJECTIVE

Sporadic early-onset colorectal cancer (EOCRC) has bad prognosis, yet is poorly represented by cell line models. We examine the key mutational and transcriptomic alterations in an organoid biobank enriched in EOCRCs.

DESIGN

We established paired cancer (n=32) and normal organoids (n=18) from 20 patients enriched in microsatellite-stable EOCRC. Exome and transcriptome analysis was performed.

RESULTS

We observed a striking diversity of molecular phenotypes, including PTPRK-RSPO3 fusions. Transcriptionally, RSPO fusion organoids resembled normal colon organoids and were distinct from APC mutant organoids, with high BMP2 and low PTK7 expression. Single cell transcriptome analysis confirmed the similarity between RSPO fusion organoids and normal organoids, with a propensity for maturation on Wnt withdrawal, whereas the APC mutant organoids were locked in progenitor stages. CRISPR/Cas9 engineered mutation of APC in normal human colon organoids led to upregulation of PTK7 protein and suppression of BMP2, but less so with an engineered RNF43 mutation. The frequent co-occurrence of RSPO fusions with SMAD4 or BMPR1A mutation was confirmed in TCGA database searches. RNF43 mutation was found in organoid from a leukaemia survivor with a novel mutational signature; and organoids with POLE proofreading mutation displayed ultramutation. The cancer organoid genomes were stable over long culture periods, while normal human colon organoids tended to be subject to clonal dominance over time.

CONCLUSIONS

These organoid models enriched in EOCRCs with linked genomic data fill a gap in existing CRC models and reveal distinct genetic profiles and novel pathway cooperativity.

Antibiotic use and risk of colorectal cancer: a systematic review and dose-response meta-analysis

BACKGROUND

It is understudied whether the posed association of oral antibiotics with colorectal cancer (CRC) varies between antibiotic spectrums, colorectal continuum, and if a non-linear dose-dependent relationship is present.

DESIGN

Three electronic databases and a trial platform were searched for all relevant studies, from inception until February 2020, without restrictions. Random-effects meta-analyses provided pooled effect-sizes (ES) with 95% confidence intervals (CI). Dose-response analyses modelling the relationship between number of days exposed to antibiotics and CRC risk were extended to non-linear multivariable random-effects models.

RESULTS

Of 6483 identified publications ten were eligible, including 4.1 million individuals and over 73,550 CRC cases. The pooled CRC risk was increased among individuals who ever-used antibiotics (ES = 1.17, 95%CI 1.05-1.30), particularly for broad-spectrum antibiotics (ES = 1.70, 95%CI 1.26-2.30), but not for narrow-spectrum antibiotic (ES = 1.11, 95% 0.93-1.32). The dose-response analysis did not provide strong evidence of any particular dose-response association, and the risk patterns were rather similar for colon and rectal cancer.

DISCUSSION

The antibiotic use associated CRC risk seemingly differs between broad- and narrow-spectrum antibiotics, and possibly within the colorectal continuum. It remains unclear whether this association is causal, requiring more mechanistic studies and further clarification of drug-microbiome interactions.

Trends and Clinical Outcomes in Young-onset Colorectal Cancer Patients

Introduction: Young individuals with colorectal cancer (CRC) tend to be diagnosed at advanced stages and are not routinely included in screening programmes. This study describes the incidence, disease pattern and factors affecting overall survival in young- onset CRC. Methods: A retrospective study of young-onset CRC patients diagnosed between 2010 and 2017 in a tertiary hospital was conducted. Results: There were 99 patients, 69.7% had left-sided while 30.3% had right-sided CRC. The mean age was 43.3 years (43.3±5.0) and 62 patients (62.6%) were male. The incidence of young-onset CRC has been on the rise since 2014. Out of 99 patients, 65 (65.7%) underwent elective surgery, 30 (30.3%) underwent emergency surgery and the remainder 5 (4.0%) were palliated. The most common presenting complaints for patients who underwent elective surgery were abdominal pain, per-rectal bleeding and altered bowel habits. For patients who required emergency surgery, 20 (66.6%) presented with intestinal obstruction and 10 (33.3%) had intestinal perforation. There were 42 (42.4%) stage III CRC and 20 (20.2%) stage IV CRC. The most frequent metastatic site was the liver (20/20, 100%). Five patients had signet ring cells (5.1%) in their histology while 15 (15.2%) had mucinous features. The overall 5-year survival of young-onset CRC was 82.0%. Advanced overall stage (hazard ratio (HR) 6.1, CI 1.03–3.62) and signet ring histology (HR 34.2, CI 2.24–5.23) were associated with poor prognosis. Conclusion: Young-onset CRC tend to be left-sided with advanced presentations. However, their 5-year survival remains favourable as compared to the general population. Keywords: Colorectal screening in the young, early-onset colorectal cancer, signet ring cell colorectal cancer

Pathogenic Germline Mutations of DNA Repair Pathway Components in Early-Onset Sporadic Colorectal Polyp and Cancer Patients

Simple Summary

Colorectal cancer (CRC) screening by immuno-fecal occult blood tests (iFOBTs) begins at age 50 in average-risk persons. However, the incidence of early-onset CRC has risen; of the cases, at least half are sporadic CRC without a family history. The authors of this study found a high percentage of de novo germline mutation in young sporadic CRC patients, as well as in sporadic colorectal polyp and control groups. All the mutated genes contribute to various DNA-repair pathways, hinting that a loss of genomic integrity play a crucial role in the development of CRC. The early identification of cancer-susceptible individuals by multigene panels in younger individuals who may be missed under current iFOBT screening could contribute to preventing CRC.

Abstract

Given recent increases in the proportion of early-onset colorectal cancer (CRC), researchers are urgently working to establish a multi-gene screening test for both inherited and sporadic cancer-susceptible individuals. However, the incidence and spectrum of germline mutations in young sporadic CRC patients in East Asian countries and, especially, in sporadic polyp carriers and normal individuals are unknown. Peripheral blood samples were collected from 43 colonoscopy-proved normal controls and from 50 polyp patients and 49 CRC patients with no self-reported family history of cancer. All participants were under 50 years old. Next-generation sequencing with a panel of 30 CRC-associated susceptibility genes was employed to detect pathogenic germline mutations. The germline mutation carrier rates were 2.3%, 4.0%, and 12.2% in the normal, polyp, and cancer groups, respectively. A total of seven different mutations in six DNA repair pathway-related genes (MLH1, BRCA1, BRCA2, CHEK2, BLM, and NTHL1) were detected in nine participants. One frameshift mutation in BRCA2 and one frameshift mutation in the CHEK2 gene were found in a normal control and two colorectal polyp patients, respectively. One young sporadic CRC patient carried two heterozygous mutations, one in MLH1 and one in BRCA1. Three mutations (MLH1 p.Arg265Cys, MLH1 p.Tyr343Ter and CHEK2 p.Ile158TyrfsTer10) were each found in two independent patients and were considered “founder” mutations. This is the first report to demonstrate high percentage of germline mutations in young sporadic colorectal polyp, CRC, and general populations. A multi-gene screening test is warranted for the proactive identification of cancer-predisposed individuals.

Colon Adenocarcinoma during Pregnancy: A Case Report and Review of the Literature

Colorectal cancer (CRC) during pregnancy presents an estimated incidence of 1 : 13,000, and it is associated with diagnostic and therapeutic challenges. Here, we present the case of a 38-year-old woman, 25 weeks and 5 days pregnant, who was transferred to our Obstetrics and Gynecology Department from a local hospital with the diagnosis of intestinal obstruction. Magnetic Resonance Imaging (MRI) showed marked distension with hydroaerial levels of the enterocolic loops upstream of a concentric parietal thickening of the descending colon, stenosing, extended longitudinally for about 4 cm. An exploratory laparotomy was performed with resection of the colon splenic flexure and mechanical end-terminal anastomosis. Histological examination of the operating piece highlighted the presence of moderately differentiated (G2) colon adenocarcinoma (stage pT3N1b). The operation was followed by a single course of oxaliplatin and 5-FU plus leukovorin. The patient had a vaginal delivery at 37 weeks + 2 days of gestational age, following induction of labor and giving birth to a male infant whose weight was 2670 gr with apgar 9/9. We underline the pivotal role of attention to unspecific symptoms, early diagnosis, and active treatment in changing the clinical course of CRC.

The prognostic impact of RAS on overall survival following liver resection in early versus late-onset colorectal cancer patients

BACKGROUND

The impact of molecular aberrations on survival after resection of colorectal liver metastases (CLM) in patients with early-age-onset (EOCRC) versus late-age-onset colorectal cancer (LOCRC) is unknown.

METHODS

Patients who underwent liver resection for CLM with known RAS, BRAF and MSI status were retrospectively studied. The prognostic impact of RAS mutations by age was analysed with age as a categorical variable and a continuous variable.

RESULTS

The study included 573 patients, 192 with EOCRC and 381 with LOCRC. The younger the age of onset of CRC, the greater the negative impact on overall survival of RAS mutations in the LOCRC, EOCRC, and ≤40 years (hazard ratio (HR), 1.64 (95% confidence interval (CI), 1.23-2.20), 2.03 (95% CI, 1.30-3.17), and 2.97 (95% CI, 1.44-6.14), respectively. Age-specific mortality risk and linear regression analysis also demonstrated that RAS mutations had a greater impact on survival in EOCRC than in LOCRC (slope: -4.07, 95% CI -8.10 to 0.04, P = 0.047, R² = 0.08).

CONCLUSION

Among patients undergoing CLM resection, RAS mutations have a greater negative influence on survival in patients with EOCRC, more so in patients ≤40 years, than in patients with LOCRC and should be considered as a prognostic factor in multidisciplinary treatment planning.

Screening for Colorectal Cancer

Colorectal cancer screening is essential to detect and remove premalignant lesions to prevent the development of colorectal cancer. Multiple screening modalities are available, including colonoscopy and stool-based testing. Colonoscopy remains the gold standard for detection and removal of premalignant colorectal lesions. Screening guidelines by the American Cancer Society now recommend initiating screening for all average-risk adults at 45 years old. Family history of colorectal cancer, other cancers, and advanced colon polyps are strong risk factors that must be considered in order to implement earlier testing. Epidemiologic studies continue to show disparities in colorectal cancer incidence and mortality and wide variability in screening rates.

Risk of colorectal cancer in patients with diabetes mellitus: A Swedish nationwide cohort study

BACKGROUND

Colorectal cancer (CRC) incidence is increasing among young adults below screening age, despite the effectiveness of screening in older populations. Individuals with diabetes mellitus are at increased risk of early-onset CRC. We aimed to determine how many years earlier than the general population patients with diabetes with/without family history of CRC reach the threshold risk at which CRC screening is recommended to the general population.

METHODS AND FINDINGS

A nationwide cohort study (follow-up:1964-2015) involving all Swedish residents born after 1931 and their parents was carried out using record linkage of Swedish Population Register, Cancer Registry, National Patient Register, and Multi-Generation Register. Of 12,614,256 individuals who were followed between 1964 and 2015 (51% men; age range at baseline 0-107 years), 162,226 developed CRC, and 559,375 developed diabetes. Age-specific 10-year cumulative risk curves were used to draw conclusions about how many years earlier patients with diabetes reach the 10-year cumulative risks of CRC in 50-year-old men and women (most common age of first screening), which were 0.44% and 0.41%, respectively. Diabetic patients attained the screening level of CRC risk earlier than the general Swedish population. Men with diabetes reached 0.44% risk at age 45 (5 years earlier than the recommended age of screening). In women with diabetes, the risk advancement was 4 years. Risk was more pronounced for those with additional family history of CRC (12-21 years earlier depending on sex and benchmark starting age of screening). The study limitations include lack of detailed information on diabetes type, lifestyle factors, and colonoscopy data.

CONCLUSIONS

Using high-quality registers, this study is, to our knowledge, the first one that provides novel evidence-based information for risk-adapted starting ages of CRC screening for patients with diabetes, who are at higher risk of early-onset CRC than the general population.

Utility of ICG fluorescence imaging with vessel clamp for ileocecal resection while preserving ileal conduit constructed after previous total cystectomy

Background

Indocyanine green (ICG) is useful for evaluating the intestinal perfusion of anastomosis. Especially for patients with prior surgeries, ICG imaging enables surgeons in visualizing the anatomical field. Here, we reported the positive and negative staining techniques of ICG fluorescence with vessel clamp for determining the optimal resection area of vessels and mesentery.

Case presentation

An 80-year-old man, who had an ileal conduit constructed after a prior total cystectomy, was diagnosed with ascending colon cancer. Although the tumor-feeding vessel was primarily the ileocecal artery, there was no detailed information about the blood running through the ileal conduit. At first, the ascending colon and the marginal vessels were transected at distal side of the tumor. Next, both, the ileocecal artery and the marginal artery of oral side of the ileal anastomotic site were clamped. Finally, we injected ICG intravenously to assess the blood flow. As a result, the blood flow between the ileal anastomotic site and transected ascending colon was not identified (negative staining). Therefore, we cut the root of the ileocecal artery, and dissected the peripheral mesocolon including the ileal anastomotic site. After the ileo-ascending colon anastomosis, we injected ICG intravenously again. The blood flow to the ileal conduit was preserved (positive staining).

Conclusion

ICG fluorescence imaging with vessel clamp can clearly visualize the demarcation line between ischemic and non-ischemic intestinal tract. In colorectal surgeries, this technique is useful to assess the anastomotic perfusion and determine optimal dissection area of vessels and mesentery in secondary intestinal surgery.

Expression pattern of ALDH1, E-cadherin, Vimentin and Twist in early and late onset sporadic colorectal cancer

Aim: To evaluate the expression pattern of ALDH1 (aldehyde dehydrogenase 1), E-cadherin, Vimentin and Twist in early and late onset sporadic colorectal cancer (CRC) and to study association of their expression with the occurrence of CRC at a young age. Materials & methods: Immunohistochemistry of ALDH1, E-cadherin, Vimentin and Twist was performed on 103 pretreated CRC biopsy samples. Results: ALDH1 expression was found to have strong correlation with early onset CRC (p < 0.0001). Conclusion: High ALDH1 expression correlates with the early onset of CRC. ALDH1 over-expression correlates with poor overall survival in colon cancer.

AGA Clinical Practice Update on Young Adult-Onset Colorectal Cancer Diagnosis and Management: Expert Review

DESCRIPTION

The objectives of this expert review are: (1) to prepare clinicians to recognize the presentation and evidence-based risk factors for young adult-onset colorectal cancer (CRC), defined as CRC diagnosed in individuals 18 - <50 years of age; (2) to improve management for patients with young onset CRC. This review will focus on the following topics relevant to young adult-onset CRC: epidemiology and risk factors; clinical presentation; diagnostic and therapeutic management including options for colorectal and extra-colonic surgical intervention, chemotherapy and immune-oncology therapies; genetic testing and its potential impact on preimplantation genetics; fertility preservation; and cancer surveillance recommendations for these individuals and their family members.

METHODS

The evidence reviewed in this manuscript is a summation of relevant scientific publications, expert opinion statements, and current practice guidelines. BEST PRACTICE ADVICE 1: With the rising incidence of people developing CRC before 50 years of age, diagnostic evaluation of the colon and rectum is encouraged for all patients, irrespective of age, who present with symptoms that may be consistent with CRC, including but not limited to: rectal bleeding, weight loss, change in bowel habit, abdominal pain, iron deficiency anemia. BEST PRACTICE ADVICE 2: Clinicians should obtain family history of colorectal and other cancers in first and second degree relatives of patients with young adult-onset CRC and discuss genetic evaluation with germline genetic testing either in targeted genes based on phenotypic presentation or in multiplex gene panels regardless of family history. BEST PRACTICE ADVICE 3: Clinicians should present the role of fertility preservation prior to cancer-directed therapy including surgery, pelvic radiation, or chemotherapy BEST PRACTICE ADVICE 4: Clinicians should counsel patients on the benefit of germline genetic testing and familial cancer panel testing in the pre-surgical period to inform which surgical options may be available to the patient with young adult-onset CRC BEST PRACTICE ADVICE 5: Clinicians should consider utilizing germline and somatic genetic testing results to inform chemotherapeutic strategies BEST PRACTICE ADVICE 6: Clinicians should offer hereditary CRC syndrome specific screening for CRC and extra-colonic cancers only to young adult-onset CRC patients who have a genetically or clinically diagnosed hereditary CRC syndrome. For patients with sporadic young adult-onset CRC, extra-colonic screening and CRC surveillance intervals are the same as for patients with older adult-onset CRC.

The incidence of young-onset colorectal cancer in Canada continues to increase

BACKGROUND

Despite decreases in the overall incidence of colorectal cancer (CRC) in Canada, a concerning increase has been observed among younger adults in recent years. The aim of this study was to update age-specific incidence trends of CRC from 1971 to 2017 in Canada.

METHODS

Data was obtained from the National Cancer Incidence Reporting System and the Canadian Cancer Registry. Age-specific annual percent changes in the incidence of CRC was estimated using NCI's Joinpoint Regression Program.

RESULTS

The incidence of CRC among adults over age 50 has continued to decrease, while the incidence among adults under the age of 50 has continued to rise. The largest increases have occurred among 20-29 and 30-39 age groups for colon and rectal cancers, respectively.

CONCLUSION

The incidence of CRC among young adults, particularly those under 40, continues to increase among men and women in Canada. Studies examining potential risk factors for young-onset CRC are required.

Patients with early-onset rectal cancer aged 40 year or less have similar oncologic outcomes to older patients despite presenting in more advanced stage; A retrospective cohort study

BACKGROUND

Early-onset colon and rectal cancer has increased in alarming rates. The present study reviewed the characteristics and outcome of early-onset rectal cancer in patients aged ≤40 years.

METHODS

This was a retrospective cohort study on rectal cancer patients who were treated in a tertiary center in the Middle East. Baseline characteristics and outcomes of patients ≤40 years were compared with patients >40 years. Main outcome measures were patients' and tumor characteristics, local recurrence, distance metastasis, overall survival (OS), and disease-free survival (DFS).

RESULTS

Among 244 patients with rectal cancer, 81 (33.2%) aged 40 years or less. 56.8% of patients ≤40 years and 49.7% of patients >40 years presented with stage III/IV disease (p = 0.36). Local recurrence and distant metastasis were detected in 10.3% and 13.2% of patients ≤40 years and in 16.9% and 13.9% of patients >40 years (p = 0.29 and 0.88). The 3-year OS and DFS rates of patients ≤40 years were 75% and 80.9% versus 74.2% and 76.5% in patients >40 years (p = 0.9 and 0.59). Patients ≤40 years presented with ulcerative carcinoma (38.3% vs 21.5%, p = 0.01) and signet-ring carcinoma (12.3% vs 2.5%, p = 0.008) more than patients > 40 years.

CONCLUSION

Early-onset rectal cancer accounted for one-third of all patients presenting with rectal cancer. Patients younger than 40 years had higher incidence of mucinous and signet-ring rectal carcinoma, and presented more with advanced stage. The age of patients did not have a significant impact on the oncologic outcome of rectal cancer.

Novel Genomic Differences in Cell-Free Circulating DNA Profiles of Young- Versus Older-Onset Colorectal Cancer

We present the first analysis examining molecular alterations detected utilizing a clinically available cell-free circulating tumor DNA (cfDNA) assay in a cohort of patients with advanced colorectal cancer (aCRC) diagnosed <50 versus ≥50 years of age. Patient characteristics and mutation frequencies were compared using cfDNA tests from 5873 patients. Patients <50 had more sequence alterations in APC, CTNNB1, and SMAD4, as well as a higher frequency of focal BRAF and ERBB2(HER2) amplifications. Our study adds further evidence suggesting that young- versus older-onset CRC may have distinct molecular underpinnings, with prognostic and therapeutic implications.

ω-3 and ω-6 Polyunsaturated Fatty Acids, Obesity and Cancer

Recently, nutraceutical bioactive compounds in foods have been discovered for their potential health benefits regarding the prevention of chronic disorders, such as cancer, and inflammatory, cardiovascular, and metabolic diseases. Dietary omega-3 polyunsaturated fatty acids (ω-3PUFAs), including alpha-linolenic acid, docosapentaenoic acid, and eicosapentaenoic acid, are mostly attractive. They are available for the customers worldwide from commonly used foods and/or as components of commercial food supplements. The anti-inflammatory and hypotriglyceridemic effects of these fatty acids are well known, whereas pro-inflammatory properties have been recognized in their dietary counterparts, the ω-6PUFAs. Both ω-3 and ω-6PUFAs contribute to the production of lipid mediators such as endocannabinoids that are notably involved in control of food intake, energy sensing, and food-related disorders. In this review, we present ω-3 and ω-6PUFAs and their derivatives, endocannabinoids; discuss the anti-obesity effects of ω-3PUFAs; their roles in inflammation and colorectal cancer development; and how their action can be co-preventative and co-therapeutic.

Early-onset colorectal cancer research: gaps and opportunities

The incidence rates of sporadic early-onset colorectal cancer (EO-CRC) are increasing rapidly in the USA and globally. Birth cohort analyses strongly suggest that changes in early life exposures to known or unknown risk factors for CRC may be driving EO disease, but the etiology of EO-CRC remains poorly understood. To address the alarming rise in sporadic EO-CRC, the National Cancer Institute and National Institute of Environmental Health Sciences convened a virtual meeting that featured presentations and critical discussions from EO-CRC experts that examined emerging evidence on potential EO-CRC risk factors, mechanisms and translational opportunities in screening and treatment.

The gut microbiome and potential implications for early-onset colorectal cancer

Recently, there has been an unexpected trend toward increased incidence of colorectal cancer in younger individuals, particularly distal colon and rectal cancer in those under age 50. There is evidence to suggest that the human gut microbiome may play a role in carcinogenesis. The microbiome is dynamic and varies with age, geography, ethnicity and diet. Certain bacteria such as Fusobacterium nucleatum have been implicated in the development of colorectal and other gastrointestinal cancers. Recent data suggest that bacteria can alter the inflammatory and immune environment, influencing carcinogenesis, lack of treatment response and prognosis. Studies to date focus on older patients. Because the microbiome varies with age, it could be a potential explanation for the rise in early-onset colorectal cancer.

High incidence of prolonged rectal bleeding and advanced stage cancer in early-onset colorectal cancer patients

Background: We examined characteristics of early-onset colorectal cancer (CRC) patients to identified factors, which may lead to earlier diagnosis. Materials & methods: This is a retrospective study with inclusion criteria: CRC diagnosed between 2012 and 2018 and age at diagnosis <50 years. Results: A total of 209 patients were included (mean age 41.8 years). Of those patients 42.5% had rectal cancer and 37.8% were stage IV at initial diagnosis. Of patients with data available for rectal bleeding history (n = 173), 50.8% presented with rectal bleeding and median time from onset of bleeding to diagnosis was 180 days (interquartile range 60–365), with longer duration noted in advanced cancer. Conclusion: Prolonged rectal bleeding history was noted in a significant proportion of early-onset CRC patients, with longer duration of rectal bleeding noted in stage IV patients. Patients and primary care physicians should be made aware of this finding in order to facilitate timely referral for diagnostic workup.

Secretome Proteomic Approaches for Biomarker Discovery: An Update on Colorectal Cancer

Searching for new cancer-related biomarkers is a key priority for the early detection of solid tumors, such as colorectal cancer (CRC), in clinically relevant biological fluids. The cell line and/or tumor tissue secretome represents a valuable resource for discovering novel protein markers secreted by cancer cells. The advantage of a secretome analysis is the reduction of the large dynamic range characterizing human plasma/serum, and the simultaneous enrichment of low abundance cancer-secreted proteins, thereby overcoming the technical limitations underlying the direct search in blood samples. In this review, we provided a comprehensive overview of recent studies on the CRC secretome for biomarker discovery, focusing both on methodological and technical aspects of secretome proteomic approaches and on biomarker-independent validation in CRC patient samples (blood and tissues). Secretome proteomics are mainly based on LC-MS/MS analyses for which secretome samples are either in-gel or in-solution trypsin-digested. Adequate numbers of biological and technical replicates are required to ensure high reproducibility and robustness of the secretome studies. Moreover, another major challenge is the accuracy of proteomic quantitative analysis performed by label-free or labeling methods. The analysis of differentially expressed proteins in the CRC secretome by using bioinformatic tools allowed the identification of potential biomarkers for early CRC detection. In this scenario, this review may help to follow-up the recent secretome studies in order to select promising circulating biomarkers to be validated in larger screenings, thereby contributing toward a complete translation in clinical practice.

The missing heritability of familial colorectal cancer

Pinpointing heritability factors is fundamental for the prevention and early detection of cancer. Up to one-quarter of colorectal cancers (CRCs) occur in the context of familial aggregation of this disease, suggesting a strong genetic component. Currently, only less than half of the heritability of CRC can be attributed to hereditary syndromes or common risk loci. Part of the missing heritability of this disease may be explained by the inheritance of elusive high-risk variants, polygenic inheritance, somatic mosaicism, as well as shared environmental factors, among others. A great deal of the missing heritability in CRC is expected to be addressed in the coming years with the increased application of cutting-edge next-generation sequencing technologies, routine multigene panel testing and tumour-focussed germline predisposition screening approaches. On the other hand, it will be important to define the contribution of environmental factors to familial aggregation of CRC incidence. This review provides an overview of the known genetic causes of familial CRC and aims at providing clues that explain the missing heritability of this disease.

Personal History of Diabetes as Important as Family History of Colorectal Cancer for Risk of Colorectal Cancer: A Nationwide Cohort Study

INTRODUCTION

Diabetes mellitus (DM) and colorectal cancer (CRC) share some risk factors, including lifestyle and metabolic disturbances. We aimed to provide in-depth information on the association of CRC risk, especially early-onset CRC, with DM, family history of CRC, and age at DM diagnosis.

METHODS

A nationwide cohort study was conducted using Swedish family cancer data sets, inpatient, and outpatient registers (follow-up: 1964-2015), including all individuals born after 1931 and their parents (12,614,256 individuals; 559,375 diabetic patients; 162,226 CRC patients).

RESULTS

DM diagnosis before the age of 50 years was associated with a 1.9-fold increased risk of CRC before the age of 50 years (95% CI for standardized incidence ratio: 1.6-2.3) vs 1.3-fold risk of CRC at/after the age of 50 years (1.2-1.4). DM diagnosis before the age of 50 years in those with a family history of CRC was associated with 6.9-fold risk of CRC before the age of 50 years (4.1-12) and 1.9-fold risk of CRC at/after the age of 50 years (1.4-2.5). Diabetic patients had a similar lifetime risk of CRC before the age of 50 years (0.4%, 95% CI: 0.3%-0.4%) to those with only a family history of CRC (0.5%, 0.5%-0.5%), double that of the population (0.2%, 0.2%-0.2%).

DISCUSSION

Our large cohort with valid information on DM and family history of cancer showed that DM is associated with increased risk of CRC in a magnitude close to having family history of CRC. Associations of DM and CRC family history with increased CRC risk were most prominent in young adults. These findings warrant further studies on harms, benefits, and cost-effectiveness of CRC screening in patients with diabetes, especially type 2, at earlier ages than in the general population.

The DNA damage response pathway as a land of therapeutic opportunities for colorectal cancer

BACKGROUND

Colorectal cancer (CRC) represents a major cause of cancer deaths worldwide. Although significant progress has been made by molecular and immune therapeutic approaches, prognosis of advanced stage disease is still dismal. Alterations in the DNA damage response (DDR) pathways are emerging as novel targets for treatment across different cancer types. However, even though preclinical studies have shown the potential exploitation of DDR alterations in CRC, systematic and comprehensive testing is lagging and clinical development is based on analogies with other solid tumors according to a tissue-agnostic paradigm. Recently, functional evidence from patient-derived xenografts and organoids have suggested that maintenance with PARP inhibitors might represent a therapeutic opportunity in CRC patients previously responsive to platinum-based treatment.

DESIGN AND RESULTS

In this review, we highlight the most promising preclinical data and systematically summarize published clinical trials in which DDR inhibitors have been used for CRC and provide evidence that disappointing results have been mainly due to a lack of clinical and molecular selection.

CONCLUSIONS

Future preclinical and translational research will help in better understanding the role of DDR alterations in CRC and pave the way to novel strategies that might have a transformative impact on treatment by identifying new therapeutic options including tailored use of standard chemotherapy.