Clinicopathologic and molecular features of sporadic early-onset colorectal adenocarcinoma: an adenocarcinoma with frequent signet ring cell differentiation, rectal and sigmoid involvement, and adverse morphologic features

A Comprehensive Comparison of Early-Onset and Average-Onset Colorectal Cancers

BACKGROUND

The causative factors for the recent increase in early-onset colorectal cancer (EO-CRC) incidence are unknown. We sought to determine if early-onset disease is clinically or genomically distinct from average-onset colorectal cancer (AO-CRC).

METHODS

Clinical, histopathologic, and genomic characteristics of EO-CRC patients (2014-2019), divided into age 35 years and younger and 36-49 years at diagnosis, were compared with AO-CRC (50 years and older). Patients with mismatch repair deficient tumors, CRC-related hereditary syndromes, and inflammatory bowel disease were excluded from all but the germline analysis. All statistical tests were 2-sided.

RESULTS

In total, 759 patients with EO-CRC (35 years, n = 151; 36-49 years, n = 608) and AO-CRC (n = 687) were included. Left-sided tumors (35 years and younger = 80.8%; 36-49 years = 83.7%; AO = 63.9%; P < .001 for both comparisons), rectal bleeding (35 years and younger = 41.1%; 36-49 years = 41.0%; AO = 25.9%; P = .001 and P < .001, respectively), and abdominal pain (35 years and younger = 37.1%; 36-49 years = 34.0%; AO = 26.8%; P = .01 and P = .005, respectively) were more common in EO-CRC. Among microsatellite stable tumors, we found no differences in histopathologic tumor characteristics. Initially, differences in TP53 and Receptor Tyrosine Kinase signaling pathway (RTK-RAS)alterations were noted by age. However, on multivariate analysis including somatic gene analysis and tumor sidedness, no statistically significant differences at the gene or pathway level were demonstrated. Among advanced microsatellite stable CRCs, chemotherapy response and survival were equivalent by age cohorts. Pathogenic germline variants were identified in 23.3% of patients 35 years and younger vs 14.1% of AO-CRC (P = .01).

CONCLUSIONS

EO-CRCs are more commonly left-sided and present with rectal bleeding and abdominal pain but are otherwise clinically and genomically indistinguishable from AO-CRCs. Aggressive treatment regimens based solely on the age at CRC diagnosis are not warranted.

The Role of Diet and Lifestyle in Early-Onset Colorectal Cancer: A Systematic Review

Simple Summary

This systematic review sifted through the exogenous dietary and lifestyle risk factors associated with early-onset colorectal cancer, going through the putative involvement of these exogenous risk factors in epigenetic and microbiota modifications. Given the burden of early-onset colorectal cancer and its globally increasing trend with scant literature on its pathogenesis, we believe it would be of benefit to highlight the importance of further systematic and large studies. Indeed, dietary and lifestyle modification could complement colorectal screening for early-onset colorectal cancer prevention.

Abstract

The incidence of early-onset colorectal cancer, defined as colorectal cancer occurring in young adults under the age of 50, is increasing globally. Knowledge of the etiological factors in young adults is far from complete. Questionable eoCRCs’ exogenous factors are represented by processed meat, sugary drinks, alcohol, Western dietary pattern, overweight and obesity, physical inactivity, and smoking, though with heterogeneous results. Therefore, we performed a systematic review to summarize the current evidence on the role of diet and lifestyle as eoCRC risk factors. We systematically searched PubMed, Scopus, and EMBASE up to July 2021, for original studies evaluating diet, alcohol, physical activity, BMI, and smoking in eoCRC and included twenty-six studies. Indeed, the exogenous factors could represent modifiable key factors, whose recognition could establish areas of future interventions through public health strategies for eoCRC primary prevention. Additionally, we discussed the role of additional non-modifiable risk factors, and of epigenetic regulation and microbiota as mediators of the eoCRC triggered by diet and lifestyle.

Prediction of hereditary nonpolyposis colorectal cancer using mRNA MSH2 quantitative and the correlation with nonmodifiable factor

BACKGROUND

Hereditary non-polyposis colon cancer is a dominantly inherited syndrome of colorectal cancer (CRC), with heightened risk for younger population. Previous studies link its susceptibility to the DNA sequence polymorphism along with Amsterdam and Bethesda criteria. However, those fail in term of applicability.

AIM

To determine a clear cut-off of MSH2 gene expression for CRC heredity grouping factor. Further, the study also aims to examine the association of risk factors to the CRC heredity.

METHODS

The cross-sectional study observed 71 respondents from May 2018 to December 2019 in determining the CRC hereditary status through MSH2 mRNA expression using reverse transcription-polymerase chain reaction and the disease’s risk factors. Data were analyzed through Chi-Square, Fischer exact, t-test, Mann-Whitney, and multiple logistics.

RESULTS

There are significant differences of MSH2 within CRC group among tissue and blood; yet, negative for significance between groups. Through the blood gene expression fifth percentile, the hereditary CRC cut-off is 11059 fc, dividing the 40 CRC respondents to 32.5% with hereditary CRC. Significant risk factors include age, family history, and staging. Nonetheless, after multivariate control, age is just a confounder. Further, the study develops a probability equation with area under the curve 82.2%.

CONCLUSION

Numerous factors have significant relations to heredity of CRC patients. However, true important factors are staging and family history, while age and others are confounders. The study also established a definite cut-off point for heredity CRC based on mRNA MSH2 expression, 11059 fc. These findings shall act as concrete foundations on further risk factors and/or genetical CRC future studies.

Prediction of hereditary nonpolyposis colorectal cancer using mRNA MSH2 quantitative and the correlation with nonmodifiable factor

BACKGROUND

Hereditary non-polyposis colon cancer is a dominantly inherited syndrome of colorectal cancer (CRC), with heightened risk for younger population. Previous studies link its susceptibility to the DNA sequence polymorphism along with Amsterdam and Bethesda criteria. However, those fail in term of applicability.

AIM

To determine a clear cut-off of MSH2 gene expression for CRC heredity grouping factor. Further, the study also aims to examine the association of risk factors to the CRC heredity.

METHODS

The cross-sectional study observed 71 respondents from May 2018 to December 2019 in determining the CRC hereditary status through MSH2 mRNA expression using reverse transcription-polymerase chain reaction and the disease's risk factors. Data were analyzed through Chi-Square, Fischer exact, t-test, Mann-Whitney, and multiple logistics.

RESULTS

There are significant differences of MSH2 within CRC group among tissue and blood; yet, negative for significance between groups. Through the blood gene expression fifth percentile, the hereditary CRC cut-off is 11059 fc, dividing the 40 CRC respondents to 32.5% with hereditary CRC. Significant risk factors include age, family history, and staging. Nonetheless, after multivariate control, age is just a confounder. Further, the study develops a probability equation with area under the curve 82.2%.

CONCLUSION

Numerous factors have significant relations to heredity of CRC patients. However, true important factors are staging and family history, while age and others are confounders. The study also established a definite cut-off point for heredity CRC based on mRNA MSH2 expression, 11059 fc. These findings shall act as concrete foundations on further risk factors and/or genetical CRC future studies.

An age stratified analysis of the biomarkers in patients with colorectal cancer

Colorectal cancer (CRC), a common malignant tumor of the digestive tract, has a high incidence and mortality rate. Several recent studies have found that aging is associated with the increasing risk of cancer. Nevertheless, the expression status and function of age-related genes in CRC is still not well understood. In the study, we comprehensively analyzed the gene expression data of CRC patients from The Cancer Genome Atlas (TCGA) database. Age-related differential expression genes (age-related DEGs) in tumor tissues compared with normal tissues of CRC were further identified. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses of age-related DEGs were performed by clusterProfiler of R. Afterwards, we used the STRING database to map the protein-protein interaction network of DEGs. We constructed prognostic model through univariate and multivariate COX regression analyses, and further evaluated their predictive power. The prognostic gene signature-related functional pathways were explored by gene set enrichment analysis (GSEA). The weighted gene co-expression network analysis (WGCNA) was used to identify key module associated with two prognostic gene signatures. Finally, we used the Metascape to perform functional enrichment analysis of genes in the key module. A total of 279 age-related DEGs were identified from the TCGA database. GO and KEGG enrichment analysis showed that the age-related DEGs were enriched in the Modulation of chemical synaptic transmission and Neuroactive ligand-receptor interaction. Moreover, we established a novel age-related gene signature (DLX2 and PCOLCE2) for overall survival in CRC, which was further predicted in both the training and validation sets. The results of GSEA demonstrated that numerous disease-related pathways were enriched in the high-risk group. We identified 43 genes related to the DLX2 and PCOLCE2 by the WGCNA co-expression network. We also found that these 43 genes were enriched in the cancer-related pathways. To sum up, the study identified an age-related gene signature for predicting the prognosis of CRC patients, which is conducive to the identification of novel prognostic molecular markers.

Cartilage Oligomeric Matrix Protein, COMP may be a Better Prognostic Marker Than CEACAM5 and Correlates With Colon Cancer Molecular Subtypes, Tumor Aggressiveness and Overall Survival

BACKGROUND

New tumor biomarkers are needed to improve the management of Colon cancer (CC), the second leading cause of cancer-related deaths in the United States. Carcinoembryonic Antigen (CEA), the translated protein of carcinoembryonic antigen-related cell adhesion molecule 5 (CEACAM5) gene, is used as a biomarker for CC. Cartilage Oligomeric Matrix Protein (COMP) is overexpressed in CC compared to normal colon tissues. This study aims to evaluate the expression of COMP by disease stage, consensus molecular subtype (CMS), its impact on disease outcomes, and comparison to CEACAM5.

MATERIALS AND METHODS

RNA-seq data from 456 CC The Cancer Genome Atlas samples and 41 matching control samples were analyzed for COMP expression and CEACAM5 expression. We stratified tumor samples by stage (I-IV), subtype (CMS1-CMS4), tumor location, and Kirsten RAt Sarcoma (KRAS) mutant status and three quartiles were established based on COMP expression. Kaplan Meier survival outcomes were evaluated.

RESULTS

COMP expression was significantly higher in tumor samples, with elevation of expression occurring in stage I and significantly increasing in stage IV. Increased COMP expression occurs in CMS4 with relatively low expression in CMS3. No significant expression difference was attributed to tumor location and KRAS mutant status. Compared to CEACAM5, COMP was a stronger molecular marker across stages and subtypes. CMS4 was associated with the high COMP expression, and higher levels of COMP were associated with poorer overall survival, disease-specific survival, and tumor progression-free intervals. CMS2 and 3 were associated with low expression and better survival.

CONCLUSION

COMP is a potential molecular biomarker for CC and may be superior to CEA as an indicator of CC.

The Prevalence of Pathogenic or Likely Pathogenic Germline Variants in a Nationwide Cohort of Young Colorectal Cancer Patients Using a Panel of 18 Genes Associated with Colorectal Cancer

INTRODUCTION

The prevalence of pathogenic or likely pathogenic germline variants (PGV) in colorectal cancer (CRC) in young patients is seen in approximately one in five patients, with the majority of cases having gene variants associated with Lynch syndrome (LS). The primary aim was to describe the prevalence of 18 genes, all associated with hereditary polyposis and CRC, in a nationwide population of young CRC (yCRC) patients, and outline disease characteristics in patients with or without germline variants.

METHODS

We screened 98 patients aged 18-40 with CRC diagnosed in 2010-2013 for variants in MSH2, MSH6, MLH1, PMS2, EPCAM, APC, MUTYH, SMAD4, BMPR1A, STK11, PTEN, POLE, POLD1, NTHL1, AXIN2, MSH3, GREM1 and RNF43 using Next Generation Sequencing. Comparisons between patients' characteristics in patients with PGV, and patients without germline variants (NPGV) were analyzed.

RESULTS

PGV were detected in twenty-four patients (24.5%), and twenty-one patients (21.1%) had variants in the mismatch repair (MMR) genes associated with LS. Variants in the APC and MUTYH genes were detected in 1% and 4%, respectively. Patients with NPGV had more advanced disease with adverse histopathological features.

CONCLUSION

PGV was detected in one in four yCRC patients, and one in five yCRC patients had disease causing variants in the mismatch repair genes associated with LS.

Total Vitamin D Intake and Risks of Early-Onset Colorectal Cancer and Precursors

BACKGROUND & AIMS

Vitamin D has been implicated in colorectal cancer (CRC) pathogenesis, but it remains unknown whether total vitamin D intake is associated with early-onset CRC and precursors diagnosed before age 50.

METHODS

We prospectively examined the association between total vitamin D intake and risks of early-onset CRC and precursors among women enrolled in the Nurses' Health Study II. Multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for early-onset CRC were estimated with Cox proportional hazards model. Multivariable-adjusted odds ratios (ORs) and 95% CIs for early-onset conventional adenoma and serrated polyp were estimated with logistic regression model.

RESULTS

We documented 111 incident cases of early-onset CRC during 1,250,560 person-years of follow-up (1991 to 2015). Higher total vitamin D intake was significantly associated with a reduced risk of early-onset CRC (HR for ≥450 IU/day vs <300 IU/day, 0.49; 95% CI, 0.26-0.93; P for trend = .01). The HR per 400 IU/day increase was 0.46 (95% CI, 0.26-0.83). The inverse association was significant and appeared more evident for dietary sources of vitamin D (HR per 400 IU/day increase, 0.34; 95% CI, 0.15-0.79) than supplemental vitamin D (HR per 400 IU/day increase, 0.77; 95% CI, 0.37-1.62). For CRC precursors, the ORs per 400 IU/day increase were 0.76 (95% CI, 0.65-0.88) for conventional adenoma (n = 1,439) and 0.85 (95% CI, 0.75-0.97) for serrated polyp (n = 1,878).

CONCLUSIONS

In a cohort of younger women, higher total vitamin D intake was associated with decreased risks of early-onset CRC and precursors.

Characteristics of Early-Onset vs Late-Onset Colorectal Cancer: A Review

Importance

The incidence of early-onset colorectal cancer (younger than 50 years) is rising globally, the reasons for which are unclear. It appears to represent a unique disease process with different clinical, pathological, and molecular characteristics compared with late-onset colorectal cancer. Data on oncological outcomes are limited, and sensitivity to conventional neoadjuvant and adjuvant therapy regimens appear to be unknown. The purpose of this review is to summarize the available literature on early-onset colorectal cancer.

Observations

Within the next decade, it is estimated that 1 in 10 colon cancers and 1 in 4 rectal cancers will be diagnosed in adults younger than 50 years. Potential risk factors include a Westernized diet, obesity, antibiotic usage, and alterations in the gut microbiome. Although genetic predisposition plays a role, most cases are sporadic. The full spectrum of germline and somatic sequence variations implicated remains unknown. Younger patients typically present with descending colonic or rectal cancer, advanced disease stage, and unfavorable histopathological features. Despite being more likely to receive neoadjuvant and adjuvant therapy, patients with early-onset disease demonstrate comparable oncological outcomes with their older counterparts.

Conclusions and Relevance

The clinicopathological features, underlying molecular profiles, and drivers of early-onset colorectal cancer differ from those of late-onset disease. Standardized, age-specific preventive, screening, diagnostic, and therapeutic strategies are required to optimize outcomes.

Rectal Cancer in Adolescent and Young Adult Patients: Pattern of Clinical Presentation and Case-Matched Comparison of Outcomes

BACKGROUND

Rectal cancer in adolescents and young adults (age ≤39) is increasing. Early diagnosis is a challenge in this subset of patients.

OBJECTIVE

This study aims to analyze the presentation pattern and outcomes of sporadic rectal cancer in adolescents and young adults.

DESIGN

This is a retrospective study.

SETTING

This study was conducted at 3 European tertiary centers.

PATIENTS

Data on adolescents and young adults operated on for sporadic rectal cancer (January 2008 through October 2019) were analyzed. To compare outcomes, adolescents and young adults were matched to a group of patients aged ≥40 operated on during the same period.

MAIN OUTCOME MEASURES

The primary outcomes measured were clinical presentation and long-term outcomes.

RESULTS

Sporadic rectal cancers occurred in 101 adolescents and young adults (2.4%; mean age, 33.5; range, 18-39); 51.5% were male, and a smoking habit was reported by 17.8% of patients. The rate of a family history for colorectal cancer was 25.7%, and of these patients, 24.7% were obese. Diagnosis based on symptoms was reported in 92.1% patients, and the mean time from first symptoms to diagnosis was 13.7 months. The most common symptom at diagnosis was rectal bleeding (68.8%), and 12% and 34% of the adolescents and young adults presented with locally advanced or metastatic disease at diagnosis. Consequently, 68.3% and 62.4% adolescents and young adults received neoadjuvant and adjuvant treatments. The rate of complete pathological response was 24.1%; whereas 38.6% patients had stage IV disease, and 93.1% were microsatellite stable. At a mean follow-up of 5 years, no difference in cancer-specific survival, but a lower disease-free survival was reported in adolescents and young adults (p < 0.0001) vs the matched group. Adolescents and young adults with stages I to II disease had shorter cancer-specific survival and disease-free survival (p = 0.006; p < 0.0001); with stage III disease, they had a shorter disease-free survival (p = 0.01).

LIMITATIONS

This study was limited by its observational, retrospective design.

CONCLUSIONS

The significantly delayed diagnosis in adolescents and young adults may have contributed to the advanced disease at presentation and lower disease-free survival, even at earlier stages, suggesting a higher metastatic potential than in older patients. See Video Abstract at http://links.lww.com/DCR/B537.

CNCER DE RECTO EN PACIENTES ADOLESCENTES Y ADULTOS JVENES CUADRO DE PRESENTACIN CLNICA Y COMPARACIN DE DESENLACES POR CASOS EMPAREJADOS

ANTECEDENTES:El cáncer de recto en adolescentes y adultos jóvenes (edad ≤ 39) está aumentando. El diagnóstico temprano es un desafío en este subgrupo de pacientes.OBJETIVO:Analizar el cuadro de presentación y los desenlaces en adolescentes y adultos jóvenes con cáncer de recto esporádico.DISEÑO:Estudio retrospectivo.ÁMBITO:Tres centros europeos de tercer nivel.PACIENTES:Se analizaron los datos de adolescentes y adultos jóvenes operados de cáncer de recto esporádico (enero de 2008 - octubre de 2019). Para comparar los desenlaces se emparejó a adolescentes y adultos jóvenes con un grupo de pacientes mayores de 40 años operados en el mismo período de tiempo.PRINCIPALES VARIABLES ANALIZADAS:Cuadro clínico, resultados a largo plazo.RESULTADOS:Los cánceres de recto esporádicos en adolescentes y adultos jóvenes fueron 101 (2,4%, edad media: 33,5, rango 18-39). El 51,5% eran hombres, el 17,8% de los pacientes fumaba. El 25,7% tentía antecedentes familiares de cáncer colorrectal. El 24,7% eran obesos. El diagnóstico con base en los síntomas se informó en el 92,1% de los pacientes, el tiempo promedio desde los primeros síntomas hasta el diagnóstico fue de 13,7 meses. El síntoma más común en el momento del diagnóstico fue el sangrado rectal (68,8%). 12% y 34% de adolescentes y adultos jóvenes presentaron enfermedad localmente avanzada o metastásica en el momento del diagnóstico. Por lo tanto, el 68,3% y el 62,4% de adolescentes y adultos jóvenes recibieron neoadyuvancia y adyuvancia. La tasa de respuesta patológica completa fue del 24,1%; mientras que el 38,6% estaban en estadio IV. El 93,1% eran microsatelite estable. Con una media de seguimiento de 5 años, no se observaron diferencias en la sobrevida específica del cáncer, pero se informó una menor sobrevida libre de enfermedad en adolescentes y adultos jóvenes (p <0,0001) frente al grupo emparejado. Los adolescentes y adultos jóvenes en estadios I-II tuvieron una sobrevida específica por cáncer y una sobrevida libre de enfermedad más corta (p = 0,006; p <0,0001); el estadio III tuvo una sobrevida libre de enfermedad más baja (p = 0,01).LIMITACIONES:Diseño observacional y retrospectivo.CONCLUSIONES:El diagnóstico notablemente demorado en adolescentes y adultos jóvenes puede contribuir a la presentación de una enfermedad avanzada y a una menor sobrevida libre de enfermedad, incluso en estadios más tempranas, lo cual implica un mayor potencial metastásico en comparación con pacientes mayores. Consulte Video Resumen en http://links.lww.com/DCR/B537.

Risk factors and clinical characteristics of early-onset colorectal cancer vs. late-onset colorectal cancer: a case-case study

BACKGROUND AND OBJECTIVES

Early-onset colorectal cancer (eoCRC), defined as colorectal cancer (CRC) before the age of 50 is increasing in incidence. We evaluated exogenous and endogenous risk factors, and clinical features of eoCRC, compared to late-onset CRC (loCRC).

METHODS

In this retrospective case-case study, patients were prospectively enrolled from 2015 to 2018. We collected clinical features (age, sex, time from symptom onset to diagnosis, symptoms, family history, smoking and alcohol habits, diabetes, BMI, and genetic analysis) and tumor characteristics. Independent risk factors for eoCRC and odds ratios (ORs) were identified.

RESULTS

Fifty-four eoCRCs and 494 loCRCs were enrolled. Patients with eoCRC experienced longer delay time from symptom onset to diagnosis: 40.7% were diagnosed within 6 months from symptoms onset, compared to 85.6% of patients with loCRC (P < 0.0001). They differed for sex, presence of symptoms, family history, smoking habit, alcohol intake, and BMI. Rectal localization was more closely associated with eoCRC (64.8%) than loCRC (34.5%, P < 0.0001). Family history of CRC was associated with eoCRC (OR = 8.8). When family history occurred with hereditary cancer syndromes, the OR for eoCRC increased to 21.

CONCLUSION

In young adults with alarming symptoms, CRC must be suspected to avoid delay time from symptom onset to diagnosis and genetic risk assessment has to be evaluated. Smoking habits, alcohol intake, and BMI are not associated with eoCRC.

Young-onset colorectal cancer: A review

Despite the general decrease in overall incidence of colorectal cancer since the early 1990s, the incidence of colorectal cancer in patients less than 50 years old has nearly doubled. A systematic review was performed using the PubMed database (2011-2020) and Cochrane Database of Systematic Reviews (2011-2021) to identify studies (published in English) evaluating epidemiologic, clinical, hereditary, and molecular features; as well as evaluation, management, and prognosis of young-onset colorectal cancer patients. Our search yielded a total of 3401 articles, after applying our inclusion criteria. We fully reviewed 94 full-length studies. This systematic review demonstrates the increasing incidence of young-onset colorectal cancer and highlights the importance of being hypervigilant for the differential diagnosis colorectal cancer when evaluating a young adult who presents with gastrointestinal symptoms.

Association Between Chemotherapy and Survival in T1 Colon Cancer With Lymph Node Metastasis: A Propensity-Score Matched Analysis

This study aimed to comprehensively examine the efficacy of chemotherapy in T1 colon cancer patients with lymph node metastasis.

Clinicopathological and Molecular Characteristics of Colorectal Signet Ring Cell Carcinoma: A Review

Colorectal signet ring cell carcinoma (SRCC) is a rare subtype of colorectal cancer (CRC) with unique characteristics. Due to the limited researches on it, a comprehensive and in-depth understanding of this subtype is still lacking. In this article, we summarize the clinicopathological features and molecular characteristics of colorectal SRCC based on a literature review. Clinically, SRCC has been associated with young age, proximal site preference, advanced tumor stage, high histological grade, high rate of lymph node involvement, frequent peritoneal metastasis, and a significantly poor prognosis. Regarding molecular characteristics, in SRCC, the mutation burden of the classic signaling pathways that include WNT/β-catenin, RAS/RAF/MAPK, and PI3K/AKT/mTOR signaling pathways are generally reduced. In contrast, some genes related to the “epithelial-mesenchymal transition (EMT) process” and the “stem cell properties”, including RNF43, CDH1, and SMAD4, as well as the related TGF-β signaling pathway have been observed more frequently altered in SRCC than in conventional adenocarcinoma (AC). In many studies but not in others, SRCC showed a higher frequency of BRAF mutation, microsatellite instability-high (MSI-H) and CpG island methylator phenotype (CIMP) positive status compared to AC. It has been proposed that colorectal SRCC consists of two subtypes, in which the MSI⁺/CIMP⁺/BRAF⁺/CD3⁺/PD-L1⁺ hypermethylated genotype is more common in the proximal colon, and may represent the potential candidate for immunotherapy. Understanding the special molecular mechanisms related to the aggressive biology of SRCC is of great importance, which may provide a theoretical basis for the development of more targeted and effective treatments for this refractory disease.

Hereditary and Inflammatory Bowel Disease-Related Early Onset Colorectal Cancer Have Unique Characteristics and Clinical Course Compared with Sporadic Disease

BACKGROUND

Early onset colorectal cancer (EoCRC), diagnosed in those <50 years old, is increasing in incidence. We sought to differentiate characteristics and outcomes of EoCRC in patients with sporadic disease or preexisting conditions.

METHODS

We evaluated 2,135 patients with EoCRC in a population-based cohort from the Canadian province of British Columbia. Patients were identified on the basis of presence of hereditary syndromes (n = 146) or inflammatory bowel disease (IBD; n = 87) and compared with patients with sporadic EoCRC (n = 1,902).

RESULTS

Proportions of patients with preexisting conditions were highest in the youngest decile of 18-29 (34.3%, P < 0.0001). Patients with sporadic EoCRC were older, more likely female, and had increased BMI (P < 0.05). IBD-related EoCRC had the highest rates of metastatic disease, poor differentiation, adverse histology, lymphovascular, and perineural invasion (P < 0.05). Survival was lower in patients with IBD (HR, 1.80; 95% CI, 1.54-3.13; P < 0.0001) and higher in hereditary EoCRC (HR, 0.47; 95% CI, 0.45-0.73; P < 0.0001) compared with sporadic. Prognosis did not differ between ulcerative colitis or Crohn's disease but was lower in those with undifferentiated-IBD (HR, 1.87; 95% CI, 1.01-4.05; P = 0.049). Lynch syndrome EoCRC had improved survival over familial adenomatous polyposis (HR, 0.31; 95% CI, 0.054-0.57; P = 0.0037) and other syndromes (HR, 0.43; 95% CI, 0.11-0.99; P = 0.049). In multivariate analysis controlling for prognostic factors, hereditary EoCRC was unchanged from sporadic; however, IBD-related EoCRC had worse overall survival (HR, 2.21; 95% CI, 1.55-3.16; P < 0.0001).

CONCLUSIONS

EoCRC is heterogenous and patients with preexisting conditions have different characteristics and outcomes compared with sporadic disease.

IMPACT

Prognostic differences identified here for young patients with colorectal cancer and predisposing conditions may help facilitate treatment planning and patient counseling.See related commentary by Hayes, p. xxx.

Trends in the age-related incidence of colon and rectal cancers in China, 2005-2015

BACKGROUND

Recent evidences showed that the incidence of colorectal cancer decreased among older adults, yet this decline didn't appear in adults younger than 50 years. Our aim was to evaluate age-related incidence trends of colon and rectal cancers in China during 2005-2015.

METHODS

A retrospective study of colon and rectal cancers was conducted using population-based data from the Chinese Cancer Registry Annual Report. Age at diagnosis was analyzed in five sub-groups (0-19, 20-34, 35-49, 50-64 and 65 years). Data including new cases, incidence, and age-standardized rates (ASRs) were classified by sex and area. Temporal trends of ASRs were determined with Joinpoint regression analysis.

RESULTS

From 2005 to 2015, colon cancer incidence decreased by -2.2% (95%CI: -3.1, -1.3) per year. A more steady decrease was seen in rectal cancer with AAPC of -0.9% (95%CI: -1.4, -0.4). Stratified by age at diagnosis, incidence trends followed a similar pattern, without age-related disparity. Females showed pronounced declines relative to males. The exception was that rural individuals showed opposite increasing trends, with 2.7% of AAPCs for colon cancer and 2.0% for rectal cancer.

CONCLUSION

A slight decline was observed in colon and rectal cancers during 2005-2015, regardless of age at diagnosis.

Neoadjuvant radiation above NCCN guidelines for rectal cancer is associated with age under 50 and early clinical stage

INTRODUCTION

Recent data suggest patients with early-onset rectal cancer (EORC) receive neoadjuvant radiation above recommended doses without oncologic benefit. The use of excessive radiation may lead to worse outcomes and patient harm. We sought to evaluate predictors of aggressive neoadjuvant radiation (A-XRT) use in EORC patients and compare this to late-onset rectal cancer (LORC) patients.

METHODS

The National Cancer Database from 2004 to 2014 was queried for rectal adenocarcinoma patients undergoing surgical resection. Patients with stage 0 or IV disease, positive margins, and incomplete data were excluded. Standard neoadjuvant radiation (S-XRT) was based upon NCCN guidelines: 25-50.4 Gray for stage II/III patients and none for stage I. Excess radiation was considered A-XRT. Patients diagnosed at age < 50 years were labeled EORC; those ≥ 50 years were LORC. Categorical data were analyzed with chi-square test. Logistic regression was used to analyze clinicodemographic associations with A-XRT.

RESULTS

45,403 patients were included: 7999 (17.6%) EORC and 37,404 (82.4%) LORC. Multivariable logistic regression demonstrated that A-XRT use among stage I patient was associated with male gender, age under 50, urban location, mucinous histology, and poor tumor differentiation. Among stage II and III patients, A-XRT use was associated with male gender, age under 50, higher education and income, and urban location. Cox hazards did not demonstrate a significant association of A-XRT use with survival.

CONCLUSION

Our data reaffirm that EORC patients more frequently receive A-XRT and that use is based on demographic features independent of tumor characteristics. Reasons for A-XRT, particularly in EORC patients, should be clarified to promote adherence to guidelines and minimize patient harm.

Care Patterns and Overall Survival in Patients With Early-Onset Metastatic Colorectal Cancer

PURPOSE

Colorectal cancer (CRC) incidence in patients younger than 50 years of age, commonly defined as early-onset (EO-CRC), is rising. EO-CRC often presents with distinct clinicopathologic features. However, data on prognosis are conflicting and outcomes with modern treatment approaches for metastatic disease are still limited.

MATERIALS AND METHODS

We prospectively enrolled patients with metastatic CRC (mCRC) to a biobanking and clinical data collection protocol from 2014 to 2018. We grouped the cohort based on age at initial diagnosis: < 40 years, 40-49 years, and ≥ 50 years. We used regression models to examine associations among age at initial diagnosis, treatments, clinicopathologic features, and survival.

RESULTS

We identified 466 patients with mCRC (45 [10%] age < 40 years, 109 [23%] age 40-49 years, and 312 [67%] age ≥ 50 years). Patients < 40 years of age were more likely to have received multiple metastatic resections (odds ratio [OR], 3.533; P = .0066) than their older counterparts. Patients with EO-CRC were more likely to receive triplet therapy than patients > 50 years of age (age < 40 years: OR, 6.738; P = .0002; age 40-49 years: OR, 2.949; P = .0166). Patients 40-49 years of age were more likely to have received anti-EGFR therapy (OR, 2.633; P = .0016). Despite differences in care patterns, age did not predict overall survival.

CONCLUSION

Despite patients with EO-CRC receiving more intensive treatments, survival was similar to the older counterpart. However, EO-CRC had clinical and molecular features associated with worse prognoses. Improved biologic understanding is needed to optimize clinical management of EO-CRC. The cost-benefit ratio of exposing patients with EO-CRC to more intensive treatments has to be carefully evaluated.

Early age onset colorectal cancer

The incidence and mortality associated with colorectal cancer (CRC) diagnosed in patients under the age of 50 have been steadily increasing. The exact etiology of these epidemiologic trends is unclear. This chapter will provide a comprehensive review on the topic of early age onset colorectal cancer (EAO-CRC), defined as colorectal cancer (CRC) diagnosed in patients under the age of 50. Topics reviewed will include the epidemiology of EAO-CRC around the world, clinical and pathological features of EAO-CRC in contrast to later age onset CRC (CRC diagnosed on those over the age of 50) and the observed molecular and somatic characteristics. This chapter will review the etiologies to EAO-CRC and the established, as well as proposed risk factors for disease. Evidence-based approaches to prevention, early detection, treatment and survivorship will be presented.

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.

Disparities in Early-Onset Colorectal Cancer

The incidence and mortality of early-onset colorectal cancer (CRC) are increasing in the United States (US) and worldwide. In the US, there are notable disparities in early-onset CRC burden by race/ethnicity and geography. African Americans, Hispanic/Latinos, and populations residing in specific regions of the Southern U.S. are disproportionately affected with CRC diagnosed at younger ages, while less is known about disparities in other countries. Reasons for these disparities are likely multi-factorial and potentially implicate differences in health determinants including biology/genetics, diet/environment, individual health behaviors, and access to high-quality health services, as well as social and policy factors. This review summarizes current understanding of early-onset CRC disparities and identifies specific research areas that will inform evidence-based interventions at individual, practice, and policy levels to reduce the global burden of this disease.

The Inherited and Familial Component of Early-Onset Colorectal Cancer

Early-onset colorectal cancer (EOCRC), defined as that diagnosed before the age of 50, accounts for 10–12% of all new colorectal cancer (CRC) diagnoses. Epidemiological data indicate that EOCRC incidence is increasing, despite the observed heterogeneity among countries. Although the cause for such increase remains obscure, ≈13% (range: 9–26%) of EOCRC patients carry pathogenic germline variants in known cancer predisposition genes, including 2.5% of patients with germline pathogenic variants in hereditary cancer genes traditionally not associated with CRC predisposition. Approximately 28% of EOCRC patients have family history of the disease. This article recapitulates current evidence on the inherited syndromes that predispose to EOCRC and its familial component. The evidence gathered support that all patients diagnosed with an EOCRC should be referred to a specialized genetic counseling service and offered somatic and germline pancancer multigene panel testing. The identification of a germline pathogenic variant in a known hereditary cancer gene has relevant implications for the clinical management of the patient and his/her relatives, and it may guide surgical and therapeutic decisions. The relative high prevalence of hereditary cancer syndromes and familial component among EOCRC patients supports further research that helps understand the genetic background, either monogenic or polygenic, behind this increasingly common disease.

Oncologic Nomogram for Stage I Rectal Cancer to Assist Patient Selection for Adjuvant (Chemo)Radiotherapy Following Local Excision

Background: Because of the low rate of lymph node metastasis in stage I rectal cancer (RC), local resection (LR) can achieve high survival benefits and quality of life. However, the indications for postoperative adjuvant therapy (AT) remain controversial. Methods: A retrospective analysis was performed in 6,486 patients with RC (pT1/T2) using the Surveillance, Epidemiology, and End Results (SEER) database. Patients were initially diagnosed from 2004 to 2016; following LR, 967 received AT and 5,519 did not. Propensity score matching (PSM) was used to balance the confounding factors of the two groups; the Kaplan-Meier method and the log-rank test were used for survival analysis. Cox proportional hazards regression analysis was used to screen independent prognostic factors and build a nomogram on this basis. X-tile software was used to divide the patients into low-, moderate-, and high-risk groups based on the nomogram risk score. Results: Multivariate analysis found that age, sex, race, marital status, tumor size, T stage, and carcinoembryonic antigen (CEA) in the non-AT group were independent prognostic factors for stage I RC and were included in the nomogram prediction model. The C-index of the model was 0.726 (95% CI, 0.689-0.763). We divided the patients into three risk groups according to the nomogram prediction score and found that patients with low and moderate risks did not show an improved prognosis after AT. However, high-risk patients did benefit from AT. Conclusion: The nomogram of this study can effectively predict the prognosis of patients with stage I RC undergoing LR. Our results indicate that high-risk patients should receive AT after LR; AT is not recommended for low-risk patients.

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.

Surgical outcomes and survival rates of colon cancer in children and young adults

INTRODUCTION

Colon cancer in children and young adults is rare. We sought to compare outcomes and survival between patients ≤and>25 years of age with colon cancer.

METHODS

Using the National Cancer Database, patients with colon cancer between 2004 and 2016 were identified. We included patients with histological codes consistent with invasive colon adenocarcinoma and excluded those missing data about treatment. Post-surgical outcomes and survival were compared.

RESULTS

Of 531,462 patients meeting criteria, 947 were ≤25 years. Patients ≤25 had more advanced disease (stage III:44.4%vs33.4%, stage IV:27.5%vs.15.3%) and higher rates of total colectomy (8.9%vs.2.7%) and proctocolectomy (5.0%vs.0.0%) than those >25 years. Stage for stage, 5-year survival was higher in patients ≤25 than those >25years. On multivariate regression, age was not associated with increased risk of mortality while male sex and uninsured status were.

CONCLUSIONS

Despite presenting with more advanced disease, patients ≤25 years with colon cancer had better survival than those >25 years.

Trends in Primary Surgical Resection and Chemotherapy for Metastatic Colorectal Cancer, 2000-2016

BACKGROUND

When, whether, and in whom primary tumor resection (PTR) for patients with metastatic colorectal cancer (CRC) is indicated remains unknown. With advances in multiagent systemic chemotherapy, PTR may be undertaken less frequently. The aim of this study was to obtain estimates of changes in the utilization of PTR and chemotherapy for metastatic CRC.

METHODS

Patients diagnosed with metastatic CRC between 2000 and 2016 were identified from Surveillance Epidemiology, and End Results (SEER) registry. Multivariable logistic regression defined odds of undergoing PTR. The analysis was also stratified by primary site (colon vs. rectum), age (younger than 50 vs. 50 y and older), and whether patients also underwent resection of metastatic sites (yes vs. no). The secondary endpoint of interest was the receipt of any chemotherapy, also assessed by multivariable logistic regression.

RESULTS

Among 99,835 patients with metastatic CRC, 55,527 (55.7%) underwent PTR. The odds of undergoing PTR decreased with a later year of diagnosis, with patients diagnosed in 2016 being 61.1% less likely to undergo surgery than those diagnosed in 2000 (adjusted odds ratio=0.39, 95% confidence interval: 0.36-0.42, P<0.0001; absolute percentage: 62.3% to 43.8%). Similar trends by year for PTR were observed among each of the subgroups, although patients with colon primary, young adults (age younger than 50 y), and patients also undergoing metastasectomy were more likely to undergo PTR (P<0.001 for all). In contrast, the odds of receiving chemotherapy increased dramatically with a later year of diagnosis (adjusted odds ratio=2.21, 95% confidence interval: 2.04-2.40, P<0.0001).

CONCLUSIONS

From 2000 to 2016, there was a sharp decline in the rate of PTR for patients with metastatic CRC, while the use of chemotherapy increased over the same period. Prospective studies are needed to define the optimal local treatment for patients with metastatic CRC.

An Eight-CpG-based Methylation Classifier for Preoperative Discriminating Early and Advanced-Late Stage of Colorectal Cancer

Aim

To develop and validate a CpG-based classifier for preoperative discrimination of early and advanced-late stage colorectal cancer (CRC).

Methods

We identified an epigenetic signature based on methylation status of multiple CpG sites (CpGs) from 372 subjects in The Cancer Genome Atlas (TCGA) CRC cohort, and an external cohort (GSE48684) with 64 subjects by LASSO regression algorithm. A classifier derived from the methylation signature was used to establish a multivariable logistic regression model to predict the advanced-late stage of CRC. A nomogram was further developed by incorporating the classifier and some independent clinical risk factors, and its performance was evaluated by discrimination and calibration analysis. The prognostic value of the classifier was determined by survival analysis. Furthermore, the diagnostic performance of several CpGs in the methylation signature was evaluated.

Results

The eight-CpG-based methylation signature discriminated early stage from advanced-late stage CRC, with a satisfactory AUC of more than 0.700 in both the training and validation sets. This methylation classifier was identified as an independent predictor for CRC staging. The nomogram showed favorable predictive power for preoperative staging, and the C-index reached 0.817 (95% CI: 0.753–0.881) and 0.817 (95% CI: 0.721–0.913) in another training set and validation set respectively, with good calibration. The patients stratified in the high-risk group by the methylation classifier had significantly worse survival outcome than those in the low-risk group. Combination diagnosis utilizing only four of the eight specific CpGs performed well, even in CRC patients with low CEA level or at early stage.

Conclusions

Our classifier is a valuable predictive indicator that can supplement established methods for more accurate preoperative staging and also provides prognostic information for CRC patients. Besides, the combination of multiple CpGs has a high value in the diagnosis of CRC.

Prognostic implication of systemic inflammatory markers in young patients with resectable colorectal cancer

PURPOSE

The prognosis of young colorectal cancer (CRC) patients has not fully been addressed. The prognostic significance of systemic inflammatory markers was examined in those patients.

METHODS

A total of 965 patients with resectable CRC were divided into young (≤ 50 years, n = 101) and old groups (> 51 years, n = 864). Neutrophil-to-lymphocyte ratio (NLR) > 5, derived NLR (dNLR) > 3, lymphocyte-to-monocyte ratio (LMR) < 2, platelet-to-lymphocyte ratio (PLR) > 150, and prognostic nutritional index (PNI) < 45 were analyzed for prognosis. Overall survival (OS) and progression-free survival (PFS) were compared using the log-rank test. A multivariate analysis was performed using a Cox proportional hazards regression model.

RESULTS

In the young group, NLR > 5, LMR < 2, and PNI < 45 were significantly associated with OS with univariate analyses. dNLR > 3 and those markers showed significance for PFS. LMR < 2 was a significant marker for poor PFS (hazard ratio [HR], 5.81; P = 0.020) in the multivariate analysis. In the old group, all inflammatory markers were significantly associated with OS and PFS with univariate analyses. LMR < 2 (HR, 2.66; P = 0.016) and PNI < 45 (HR, 2.14; P = 0.016) were independently associated with OS in multivariate analyses. PLR > 150 (HR, 1.45; P = 0.036) and PNI < 45 (HR, 1.73; P = 0.002) were significant markers for PFS.

CONCLUSION

Systemic inflammation might be one of biologic factors that influence on prognosis of young CRC.

Is Colorectal Cancer in Patients Younger Than 50 Years of Age the Same Disease as in Older Patients?

The incidence of colorectal cancer (CRC) has declined steadily in persons over age 50 years of age, largely due to screening. In contrast, incidence rates have increased rapidly in younger adults (<50 years of age),¹ raising the question of whether young-onset CRC is a distinct disease with unique biologic features or if it is the same disease occurring at a younger age. Studies comparing younger and older patients diagnosed with CRC have reported differences in clinical and molecular features, including tumor location, stage, and histology.^2-6 However, increasing use of screening colonoscopy in the population has changed characteristics of CRC diagnosed over 50 years of age (eg, higher proportion now diagnosed with proximal tumors and/or at an earlier stage),⁷ so it is challenging to draw conclusions about the importance of these findings. To address this challenge, we compared characteristics of younger and older CRC patients in a predominantly unscreened population.

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.

Germline Profiling and Molecular Characterization of Early Onset Metastatic Colorectal Cancer

Background

Early onset colorectal cancer (EO CRC) is a heterogeneous colorectal cancer subtype with obvious hereditary tendencies and increasing incidence. We sought to determine the susceptibility genes and molecular characteristics of EO CRC.

Methods

330 EO metastatic CRC (mCRC) (≤55 years) and 110 average-onset (AO) mCRC patients (>55 years) were enrolled. Capture-based targeted sequencing was performed on tumor tissue and paired white blood cells using a sequencing panel of 520 genes. The association between molecular alterations and overall survival (OS) was analyzed.

Results

Of the 330 EO mCRC patients, 31 carried pathogenic or likely pathogenic germline mutations, with 16 of them diagnosed with lynch syndrome. Fifteen patients had germline mutations in non-mismatch repair genes, including four in MUTHY, three in RAD50, one in TP53, and eight in other genes. Twenty-nine genes were recurrently mutated in EO mCRC, including TP53, APC, KRAS, SMAD4, and BRCA2. The majority of genomic alterations were comparable between EO and AO mCRC. EO mCRC patients were more likely to have a high tumor mutation burden (p < 0.05). RNF43, RBM10, TSC, and BRAF V600E mutations were more commonly observed in EO mCRC, while APC, ASXL1, DNMT3B, and MET genes were more commonly altered in AO patients. At the pathway level, the WNT pathway was the only differentially mutated pathway between EO and AO mCRC (p < 0.0001). The wild-type WNT pathway (p = 0.0017) and mutated TGF-β pathway (p = 0.023) were associated with unfavorable OS in EO mCRC.

Conclusions

Approximately one in 10 EO mCRC was associated with hereditary tumors. The spectrum of somatic alterations was largely comparable between EO and AO mCRC with several notable differences.

Comparison of metastasis between early-onset and late-onset gastric signet ring cell carcinoma

Background

There is little knowledge to date about the distant metastasis of early-onset gastric signet ring cell carcinoma (SRCC) or the difference in metastasis based on age. Therefore, we conducted a comprehensive retrospective study using the Surveillance, Epidemiology, and End Results (SEER) database and data from our hospital.

Methods

Patients were collected from the SEER database and our hospital. Univariate and multivariate logistic regression analyses and propensity score matching (PSM) were used to identify risk factors for metastasis. K-M survival curves were generated to analyse patient survival.

Results

In total, we retrieved 2052 EOGC patients diagnosed with SRCC from the SEER database and included 403 patients from our hospital. K-M survival curves showed that late-onset SRCC patients had worse survival than early-onset patients but that late-onset SRCC patients were less likely to have distant metastasis, as validated by SEER data (OR = 0.462, 95%CI, 0.272–0.787; P = 0.004) and our data (OR = 0.301, 95%CI, 0.135–0.672; P = 0.003). Multivariate logistic regression and PSM analysis revealed that age of 45 or younger was an independent risk factor for distant metastasis.

Conclusion

Our study showed that distant metastasis was more common in early-onset SRCC than in late-onset SRCC. However, further studies are needed to explore the potential aetiologic basis for this disparity.

Clinicopathological Characteristics and Outcome of Adolescent and Young Adult-Onset Microsatellite Stable Colorectal Cancer Patients

Purpose: Colorectal cancer (CRC) incidence is increasing in adults younger than 50 years. This study evaluated clinicopathological characteristics and outcome of adolescent and young adult (AYA)-onset sporadic CRC patients. Methods: Medical records of patients who were diagnosed adenocarcinoma of colon or rectum at Siriraj Hospital between 2007 and 2018 were retrospectively reviewed. The patients were classified into two groups: AYA-onset CRC (age 15-39 years) and adult-onset CRC (age >50 years). Associations between sporadic microsatellite stable (MSS) AYA-/adult-onset CRC and clinicopathological features and outcome were evaluated. Results: A total of 203 patients were diagnosed with AYA-onset CRC with no known history of familial CRC syndromes, 119 had data on mismatch repair status; 98 confirmed MSS CRC. AYA-onset CRC patients were commonly found with left-sided rather than right-sided tumors (77.1% vs. 22%) and late stage of disease (80.7% in stage III-IV vs. 19.3% in stage I-II). Compared with adult-onset CRC (218 patients), AYA-onset MSS CRC had more patients with female gender (p = 0.038), perineural invasion (p = 0.003), and signet ring cell/mucinous histology (p = 0.132). On univariate analysis, male gender and mucinous/signet ring cell histology had worse overall survival (OS) (p = 0.004 and p = 0.072, respectively) and remained significant in multivariate analysis for signet ring cell histology (p = 0.008). There was no difference in disease-free survival and OS between both age groups. Conclusions: Sporadic MSS AYA-onset CRC patients were associated with female gender and aggressive pathological characteristics. However, there was no difference in survival outcome between AYA-onset and adult-onset groups.

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 genetic and epigenetic landscape of early-onset colorectal cancer

Colorectal cancer (CRC) in individuals under the age of 50 is a problem that is increasing in USA and around the world. In this review, we discuss the degree to which early-onset (EO)CRC may be due to unsuspected Lynch syndrome or other inherited germline variants that predispose to cancer, describe the known somatic genetic alterations in EO tumors and discuss alterations in DNA methylation. Approximately 20% of EOCRCs can be attributed to identifiable germline mutations in genes that cause familial cancer syndromes. A variety of other genetic/epigenetic alterations have also been reported. We conclude that this is a heterogeneous problem, that requires a comprehensive analysis of genetic/epigenetic signatures to better understand EOCRC. Various subsets of EOCRCs must be analyzed individually for clues regarding the etiologies and possible specific therapies for this disease.

Aggressive Colorectal Cancer in the Young

Despite the steady decline in the incidence of colorectal cancer (CRC) and cancer-related mortality in Americans of 50 years and older over the last few decades, there has been a disturbing trend of steadily rising incidence in early-onset colorectal cancer (EOCRC), defined as CRC in those younger than 50 years. With the incidence of EOCRC increasing from 4.8 per 100,000 in 1988 to 8.0 per 100,000 in 2015, and with the decreased rates in those older than 50 years largely attributed to improved screening in the older population, new screening recommendations have recently lowered the age for screening average-risk individuals from 50 to 45. EOCRC has been found to present differently from late-onset CRC, with a higher proportion of patients presenting with left-sided and rectal cancer, more aggressive histological features, and more advanced stage at the time of diagnosis. This article reviews the most recent evidence from population-based studies and institutional series, as well as the newest screening guidelines, and provides an up-to-date summary of our current understanding of EOCRC, from clinical presentation to tumor biology and prognosis, and future directions in treatment and prevention.

Genomic and molecular alterations associated with early-onset and adolescent and young adult colorectal cancer

While the incidence of colorectal cancer (CRC) in the US has declined at a pace of 3% annually between 2003 and 2012, there has been an increase in the incidence of early-onset colorectal cancer (EOCRC). The reasons for this increase are unclear. Diet, the environment, the microbiome and alcohol consumption have all been proposed as contributing factors. There is the possibility that EOCRC has a unique biology. Overlapping with the EOCRC age range is CRC in adolescent and young adults (AYA) that share many molecular characteristics with EOCRC. The purpose of this review is to cover current progress in our understanding of the biology of CRC in the context of adolescent and young adult CRC and EOCRC and discuss future directions.

Early-onset colorectal cancer: more than one side to the story

Aim: To determine the impact of tumor sidedness on all-cause mortality for early- (age 18–49 years) and older-onset (age ≥50 years) colorectal cancer (CRC). Materials & methods: We conducted a retrospective study of 650,382 patients diagnosed with CRC between 2000 and 2016. We examined the associations of age, tumor sidedness (right colon, left colon and rectum) and all-cause mortality. Results: For early-onset CRC (n = 66,186), mortality was highest in the youngest age group (18–29 years), driven by left-sided colon cancers (vs 50–59 years, hazard ratio: 1.18; 95% CI: 1.03–1.34). 5-year risk of death among 18–29-year-olds with left-sided colon cancer (0.42, 95% CI: 0.38, 0.46) was higher than all other age groups. Conclusion: Left-sided colon cancers are enriched in younger adults and may be disproportionately fatal.

Clinicopathologic and Racial/Ethnic Differences of Colorectal Cancer Among Adolescents and Young Adults

Despite overall reductions in colorectal cancer burden, incidence rates continue to rise among younger patients, and causes remain unknown. We examined differences in clinicopathologic and racial/ethnic characteristics within the adolescent and young adult (AYA) population diagnosed with colorectal cancer in the United States.

Disparate and Alarming Impact of Gastrointestinal Cancers in Young Adult Patients

BACKGROUND

The rise in the incidence of gastric cancer (GC) and colorectal cancer (CRC) in young adults (YA) remains unexplained. We aim to identify differences in these malignancies between YA and older patients.

PATIENTS AND METHODS

We retrospectively analyzed the California Cancer Registry for all GC and CRC cases from 2000 to 2012. Pearson's Chi square analysis and stepwise regression model with backward elimination were used to analyze differences in demographic, clinical, and histopathologic features, and log-rank test to compare survival between young (≤ 40 years) and older adults (41-90 years) with GC or CRC, separately.

RESULTS

We analyzed 19,368 cases of GC and 117,415 cases of CRC. YA accounted for 4.6% of GC (n = 883) and 2.8% of CRC (n = 3273) patients. Compared with older patients, YA were more likely to be Hispanic (P < 0.0001) and have poorly differentiated (P < 0.0001), higher histologic grade (P < 0.0001), and signet ring features (P < 0.0001). Synchronous peritoneal metastases were more common in YA patients (32.1% vs. 14.1% GC, 8.8% vs. 5.4% CRC, P < 0.0001). The 5-year overall survival (OS) of YA with CRC or GC was longer than that of older patients with the same stage of malignancy; except YA with stage I GC, who demonstrated poor OS and disease-specific survival (DSS) (65.1% and 67.9%, respectively) which were significantly worse than those of adults aged 41-49 years (70.7% and 76.2%, respectively) and 50-64 years (69.1% and 78.1%, respectively).

CONCLUSIONS

YA with GC or CRC have distinctly worse clinical and histopathologic features compared with older patients and are disproportionately of Hispanic ethnicity. These results contribute to improving understanding of younger versus older GI cancer patients.

Sporadic colorectal cancer in adolescents and young adults: a scoping review of a growing healthcare concern

PURPOSE

Sporadic colorectal cancer (CRC) amongst adolescents and young adults (AYA) is increasing in incidence. The reasons for this trend are not well understood. Current guidelines do not specifically address this patient cohort. A scoping review was performed to summarise the range of available evidence and identify key areas that need to be addressed in current guidelines.

METHODS

A systematic literature search was conducted adhering to the PRISMA statement. All potentially eligible studies were screened, and data extraction was performed by two reviewers independently. The studies were then divided into 5 broad subgroups: (1) risk factors, (2) screening, (3) clinicopathological and molecular features, (4) presentation and (5) management. Descriptive statistics were used for data analysis.

RESULTS

A total of 17 studies were included from 2010 to 2019. Overall, young adults with CRC tend to present with non-specific symptoms. The majority of these patients have a delayed diagnosis and more advanced disease at presentation, with a rise in prevalence of distal colon and rectal cancers. AYAs tend to have poorly differentiated tumours and are managed more aggressively. Overall 5-year survival varies between studies.

CONCLUSION

This is, to our knowledge, the first scoping review presenting the range of available evidence on CRC in AYAs. Although the rise in incidence is recognised by specialist bodies, recommendations are limited by the sparsity of available data. We seek to highlight the need for further research, define the role of earlier screening and raise awareness to promote thorough assessment of young patients.

Early-onset colorectal cancer: A distinct entity with unique genetic features

The aim of the present study was to elucidate the genetic features of early-onset colorectal cancer (CRC), particularly the genetic mutations that may be regarded as prognostic and/or predictive markers in CRC and other malignancies. In total, 40 patients with non-polyposis CRC aged 35 or younger were selected. The formalin-fixed, paraffin-embedded tumors acquired were subjected to mismatch repair (MMR) protein immunochemical staining and gene analysis with next-generation sequencing (44 exons, 17 genes; Ion Torrent Sequencing Platform). A total of 11 (27.5%) tumors presented with MMR protein deficiency (dMMR) and 26 (65%) tumors harbored one or more genetic mutations, including K-RAS proto-oncogene (35%), phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA; 20%), B-Raf proto-oncogene (5%), erb-b2 receptor tyrosine kinase 2 (5%), discoidin domain receptor tyrosine kinase 2 (5%), N-RAS proto-oncogene (2.5%), KIT proto-oncogene (2.5%), TSC complex subunit 1 (2.5%), DNA methyltransferase 3 alpha (2.5%) and ABL proto-oncogene 1 (2.5%). Of the dMMR tumors, 81.8% (9/11) of cases presented with mutations in the tested genes, while only 58.6% (17/29) of the MMR-proficient (pMMR) tumors presented with these (P=0.158). PI3KCA was frequently mutated in dMMR tumors compared to pMMR tumors (P=0.025). In a subgroup with a family history of CRC, the dMMR status (P<0.001) and PIK3CA genetic mutation status (P=0.01) were more frequently observed compared to the other two groups (with a family history of other cancer types or no malignancy). Almost all patients who had relatives with CRC presented with both dMMR and other genetic mutations, while this was not observed in the patients who had relatives with other types of carcinoma. Certain genetic mutations that are rarely reported in CRC were only identified in those patients with a family history of carcinoma. In conclusion, non-polyposis CRC in young adults presents as a distinct entity with a unique set of genetic features. However, investigation of more cases in further studies is required to verify the present results.

Recent Trends and Overall Survival of Young Versus Older Adults With Stage II to III Rectal Cancer Treated With and Without Surgery in the United States, 2010-2015

BACKGROUND

The omission of surgery via nonoperative management (NOM) for rectal cancer may be increasing, and this strategy could be particularly attractive for younger patients, whose incidence of rectal cancer has been rising. We sought to assess trends in NOM in young (younger than 55 y) versus older adult (55 y and older) rectal cancer cohorts.

METHODS

The National Cancer Database was used to identify patients diagnosed with stage II to III rectal cancer between 2010 and 2015. Multivariable logistic regression defined the association between sociodemographic variables and odds of NOM, including an age (18 to 54 vs. 55+ y)×surgery (surgery vs. NOM) interaction term. Adjusted Cox regression models compared overall survival between NOM versus surgery.

RESULTS

Among 22,561 patients with a median follow-up of 37.5 months, the utilization rate of NOM increased from 10.7% (2010) to 15.2% (2015). Older patients were more likely to receive NOM, although rates also increased among young (7.1% to 10.6%). Black patients were also more likely to receive NOM (P<0.001). Among the entire cohort, NOM was associated with worse overall survival (adjusted hazard ratio [AHR]=2.90, 95% confidence interval [CI]: 2.67-3.15) and there was a statistically significant age×NOM interaction (P=0.01) such that the effect of NOM on survival was worse for younger (AHR=3.37, 95% CI: 2.82-4.02) as compared with older patients (AHR=2.49, 95% CI: 2.27-2.74).

CONCLUSIONS

The increasing trend for NOM in stage II to III rectal cancer may be driven by disparities in treatment. Management with NOM appears to be associated with poorer survival, particularly in younger patients and could worsen outcomes for groups already at risk for suboptimal cancer care.

Histology of Colorectal Carcinoma: Proven and Purported Prognostic Factors

Although tumor stage has a profound influence on prognosis, several histologic features are also important. These parameters predict biological behavior and can be used by clinicians to determine whether patients are at high risk for disease progression and, thus, are candidates for adjuvant therapy, particularly when they have localized (ie, stage II) disease. This article summarizes the evidence supporting the prognostic values of various histologic parameters evaluated by pathologists who assign pathologic stage to colorectal cancers. Criteria to be discussed include histologic subtype, tumor grade, lymphatic and perineural invasion, tumor budding, and host immune responses.

Colorectal Cancer in Persons Under Age 50: Seeking Causes and Solutions

Early onset colorectal cancer (EOCRC) refers to colorectal cancer (CRC) in individuals under age 50. Although the incidence and mortality due to later onset CRC (≥50 years) has been declining over several decades, both are increasing in those under 50. EOCRC is more likely to occur in the distal colon and rectum. There are some unique pathologic and genetic features to these tumors; they are not usually associated with a germline mutation in a gene that predisposes to cancer, and at least some may have a distinct pathogenesis. Initiating CRC screening at an earlier age (40-45 years of age) would presumably detect more early stage and asymptomatic EOCRCs, but this would imply a major additional health care burden. The understanding of EOCRC and the optimal management approach to this problem are unsolved problems.

Increasing Incidence of Young-Onset Colorectal Carcinoma A 3-Country Population Analysis

BACKGROUND

The overall incidence of colorectal carcinoma is declining in Western populations; however, single country series demonstrate an increase in young-onset (<50 years) colorectal carcinoma.

OBJECTIVE

The purpose of this study was to determine whether the pattern of increasing incidence of young-onset colorectal carcinoma is consistent across 3 Western populations.

DESIGN

This is a population incidence study.

SETTINGS

National cancer registries of New Zealand, Sweden, and Scotland were used.

PATIENTS

The incidence of colorectal carcinoma was calculated from population data for 3 countries over 2 to 4 decades.

MAIN OUTCOME MEASURES

The incidence of colorectal carcinoma was measured. Incidence rate ratios were determined and data were stratified by subsite (colon versus rectum), sex, and age (<50, 50-79, and ≥80 y).

RESULTS

Overall colorectal carcinoma rates declined in New Zealand, remained stable in Scotland, and increased in Sweden. In all 3 populations, there was an increasing incidence of rectal carcinoma in those aged <50 years. Young-onset rectal carcinoma increased in New Zealand (1995-2012: incidence rate ratio = 1.18 (men) and 1.13 (women)), with declining incidence in all other age groups. Colon carcinoma did not increase in the population aged <50 years, with the exception of distal colonic carcinoma in men. Overall, rectal carcinoma incidence increased (1970-2014) in Sweden; however, increases in those <50 years of age exceeded increases in other age groups (incidence rate ratio = 1.14 (males) and 1.12 (females)). Distal colon carcinoma increases were most marked in the population aged <50 years. In Scotland (1990-2014), young-onset rectal carcinoma incidence increased (incidence rate ratio = 1.23 (males) and 1.27 (females)), with a smaller increase in colon carcinoma.

LIMITATIONS

Limitations include its registry-based, population incidence research.

CONCLUSIONS

This study shows an increase in young-onset rectal carcinoma in 3 national populations; this observation may provide a focus for looking at the role of environmental influences on the etiology of this increase and therefore to explore strategies for prevention. See Video Abstract at http://links.lww.com/DCR/B194. AUMENTO DE LA INCIDENCIA DE CARCINOMA COLORRECTAL DE INICIO JOVEN: UN ANÁLISIS DE POBLACIÓN DE TRES PAÍSES: La incidencia global de carcinoma colorrectal está disminuyendo en las poblaciones occidentales. Sin embargo, las series de un solo país demuestran un aumento en el carcinoma colorrectal de inicio joven (pacientes menores de 50 años).Determinar si el patrón de incidencia en aumento de carcinoma colorrectal de inicio joven es consistente en tres poblaciones occidentales.Estudio de incidencias de población en tres países.Registros nacionales de cáncer de Nueva Zelanda, Suecia y Escocia.la incidencia de carcinoma colorrectal se calculó a partir de datos de población de tres países durante dos o a cuatro décadas.Incidencia de carcinoma colorrectal. Se determinaron las tasas de incidencia y los datos se estratificaron por subsitio (colon versus recto), además de sexo y edad (<50, 50-79 y ≥ 80).las tasas generales de carcinoma colorrectal disminuyeron en Nueva Zelanda, se mantuvieron estables en Escocia y aumentaron en Suecia. En las tres poblaciones, hubo una incidencia creciente de carcinoma rectal en pacientes menores de 50 años. El carcinoma rectal de inicio juvenil aumentó en Nueva Zelanda (1995-2012): tasa de incidencia de 1,18 [varones] y 1,13 [mujeres], con una disminución de la incidencia en todos los demás grupos de edad. El carcinoma de colon no aumentó en la población de < 50 años, con la excepción del carcinoma de colon distal en hombres. En general, la incidencia de carcinoma rectal aumentó (1970-2014) en Suecia; sin embargo, los aumentos en aquellos de <50 años excedieron los aumentos en otros grupos de edad: tasa de incidencia 1.14 [hombres] y 1.12 [mujeres]. Los aumentos del carcinoma de colon distal fueron más marcados en la población de < 50 años. En Escocia (1990-2014), la incidencia de carcinoma rectal de inicio juvenil aumentó: relación de tasa de incidencia 1.23 [hombres] y 1.27 [mujeres], con un aumento menor en el carcinoma de colon.Investigación de incidencia poblacional basada en registros nacionales.Este estudio muestra un aumento en el carcinoma rectal de inicio joven en tres poblaciones nacionales. Esta observación puede indicar un enfoque para la examinación de influencias ambientales en la etiología de este aumento y, por lo tanto, explorar estrategias para la prevención. Consulte Video Resumen en http://links.lww.com/DCR/B194. (Traducción-Dr Adrián Ortega).

Differences in Pathology and Mutation Status Among Colorectal Cancer Patients Younger Than, Older Than, and of Screening Age

BACKGROUND

Screening protocols for colorectal cancer are broadly recommended and effective in reducing mortality. However, populations from different age groups can harbor distinct pathologic and molecular profiles that can also be influenced by screening and polyp resection, especially in older ages.

PATIENTS AND METHODS

We retrospectively analyzed tumors from stage IV colorectal cancer patients from a central pathology laboratory in Brazil that is a reference for mutational profiling countrywide. Patients were classified into age groups as follows: prescreening age (PrSA; < 45 years old), screening age (SA; 45-75 years old), and postscreening age (PoSA; > 75 years old). Every tumor was centrally reviewed by the pathologist. Groups were compared regarding clinicopathologic features, and the presence of RAS (renin-angiotensin system) and BRAF (v-Raf murine sarcoma viral oncogene homolog B) mutations.

RESULTS

We included 1635 patients (215 PrSA, 1213 SA, 207 PoSA). There was no difference among groups regarding sidedness (P = .65) and KRAS (Kirsten rat sarcoma viral oncogene) mutations (P = .57). Stage IV disease at diagnosis (P = .04), the presence of a signet-ring cell component (P < .001), and poorly differentiated tumors (P = .02) were most common in young patients, while BRAF and NRAS (neuroblastoma RAS viral (v-ras) oncogene homolog) mutations were significantly more common among PoSA patients (P = .002 and .03, respectively). When divided by age decade, KRAS mutations seem to have a stable frequency among all ages, while the BRAF mutation rate increased with increasing age.

CONCLUSION

BRAF mutations are more frequent among PoSA patients, and this seems to be a continuous trend. PrSA and PoSA patients seem to present a distinct profile from SA, including differences in molecular and pathologic aspects. These findings could impact the frequency of screening tests among different age groups.

Early-onset colorectal cancer: initial clues and current views

Over the past several decades, the incidence of early-onset colorectal cancer (EOCRC; in patients <50 years old) has increased at an alarming rate. Although robust and scientifically rigorous epidemiological studies have sifted out environmental elements linked to EOCRC, our knowledge of the causes and mechanisms of this disease is far from complete. Here, we highlight potential risk factors and putative mechanisms that drive EOCRC and suggest likely areas for fruitful research. In addition, we identify inconsistencies in the evidence implicating a strong effect of increased adiposity and suggest that certain behaviours (such as diet and stress) might place nonobese and otherwise healthy people at risk of this disease. Key risk factors are reviewed, including the global westernization of diets (usually involving a high intake of red and processed meats, high-fructose corn syrup and unhealthy cooking methods), stress, antibiotics, synthetic food dyes, monosodium glutamate, titanium dioxide, and physical inactivity and/or sedentary behaviour. The gut microbiota is probably at the crossroads of these risk factors and EOCRC. The time course of the disease and the fact that relevant exposures probably occur in childhood raise important methodological issues that are also discussed.

Clinical characteristics and a rising incidence of early-onset colorectal cancer in a nationwide cohort of 521 patients aged 18-40 years

BACKGROUND

The incidence of early-onset colorectal cancer (eoCRC) has been reported to increase, and patients with eoCRC seem to be diagnosed at more advanced stages compared to elderly patients. The aim of this study was to describe patient and disease characteristics, symptomatology and the incidence of eoCRC in a national cohort.

MATERIALS AND METHODS

521 eoCRC patients (≤40 years old) diagnosed with histologically verified colorectal cancer (CRC) during the years 2001-2013 were identified in national databases and compared to more than 15,000 CRC patients aged 66-75 years. Age-adjusted incidence was calculated for eoCRC patients and various sub-analyses were performed.

RESULTS

More advanced stages were seen in eoCRC patients compared to elderly patients (stage II: p < 0.001, III: p = 0.01 and IV: p < 0.01). Differences were statistically significant in colon cancer, but not in rectal cancer. A significant difference in sex distribution was seen between right and left-sided tumors in the eoCRC group. The age-adjusted incidence rate increased during the study period (1.60-2.55 per 100.000), and significant annual percent changes (APC) were seen in young females (APC = 4.73) and left-sided tumor localization (including rectal cancer) (APC = 4.54), respectively.

CONCLUSION

In this nationwide cohort of eoCRC patients, our results confirm that young patients are diagnosed at advanced stages, and that the incidence of eoCRC is increasing.