Early-Onset Gastrointestinal Malignancies: An Investigation into a Rising Concern

There is growing recognition of early-onset gastrointestinal (GI) malignancies in young adults < 50 years of age. While much of the literature has emphasized colorectal cancer, these also include esophageal, gastric, liver, pancreatic, and biliary tract malignancies. Various factors, including lifestyle, hereditary, and environmental elements, have been proposed to explain the rising incidence of GI malignancies in the younger population. This review aims to provide an overview of the recent literature, including global trends and information regarding genetic and environmental risk factors.

A Perspective Review on Diet Quality, Excess Adiposity, and Chronic Psychosocial Stress and Implications for Early-Onset Colorectal Cancer

Colorectal cancer (CRC) is the third most common cancer worldwide. Although the overall incidence of CRC has been decreasing over the past 40 y, early-onset colorectal cancer (EOCRC), which is defined as a CRC diagnosis in patients aged >50 y has increased. In this Perspective, we highlight and summarize the association between diet quality and excess adiposity, and EOCRC. We also explore chronic psychosocial stress (CPS), a less investigated modifiable risk factor, and EOCRC. We were able to show that a poor-quality diet, characterized by a high intake of sugary beverages and a Western diet pattern (high intake of red and processed meats, refined grains, and foods with added sugars) can promote risk factors associated with EOCRC development, such as an imbalance in the composition and function of the gut microbiome, presence of chronic inflammation, and insulin resistance. Excess adiposity, particularly obesity onset in early adulthood, is a likely contributor of EOCRC. Although the research is sparse examining CPS and CRC/EOCRC, we describe likely pathways linking CPS to tumorigenesis. Although additional research is needed to understand what factors are driving the uptick in EOCRC, managing body weight, improving diet quality, and mitigating psychosocial stress, may play an important role in reducing an individual's risk of EOCRC.

Differential landscape of immune evasion in oncogenic RAS-driven primary and metastatic colorectal cancers

Oncogenic drivers such as KRAS extensively modulate the tumor inflammatory microenvironment (TIME) of colorectal cancer (CRC). The influence of KRAS on modulating immune cell composition remains unclear. The objective of this study was to identify signatures of infiltrative immune cells and distinctive patterns that differ between RAS wild-type (WT) and oncogenic mutant (MT) CRC that explain immune evasion in MT tumors. A total of 7,801 CRC specimens were analyzed using next-generation DNA sequencing, whole-exome sequencing, and/or whole transcriptome sequencing. Deficiency of mismatch repair (dMMR)/microsatellite instability (MSI) and tumor mutation burden (TMB) were also assessed. KRAS mutations were present in 48% of CRC, similarly distributed in patients younger than vs. 50 years and older. In microsatellite stable (MSS) KRAS MT tumors, composition of the TIME included higher neutrophil infiltration and lower infiltration of B cells. MSI-H/dMMR was significantly more prevalent in RAS WT (9.1%) than in KRAS MT (2.9%) CRC. In MSS CRC, TMB-high cases were significantly higher in RAS MT (3.1%) than in RAS WT (2.1%) tumors. KRAS and NRAS mutations are associated with increased neutrophil infiltration, with codon-specific differences. These results demonstrate significant differences in the TIME of RAS mutant CRC that match previous reports of immunoevasive characteristics of such tumors.

Surgical and survival outcomes of early-onset colorectal cancer patients: a single-centre descriptive Australian study

BACKGROUND

Early-onset colorectal cancer (EOCRC) incidence is increasing in Australia. However, no Australian studies have reported on EOCRC patients' surgical management and survival patterns.

METHODS

A retrospective study of 111 EOCRC patients treated at the Royal Prince Alfred Hospital (RPAH), Sydney, Australia between January 2013 and December 2021 was performed. RPAH is a quaternary referral centre for pelvic exenteration (PE) and cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS/HIPEC).

RESULTS

Most patients had left-sided tumours (76.58%) and stage IV disease at the time of presentation (37.85%). 27.93% of patients underwent either CRS/HIPEC and PE and 72.07% of patients underwent other colorectal resections of which the most common was low anterior resection (19.82%). A stoma was fashioned in 50.54% of patients. Complications occurred in 54.95% of patients of which most were Clavien-Dindo grade II (47.54%). Absolute 1-, 3- and 5-year time intervals were 93.69%, 87.39% and 85.48%. Disease-free and overall survival were poorer in stage IV patients who had PE, followed by CRS/HIPEC then other colorectal resections (P < 0.001 and P = 0.003).

CONCLUSIONS

Stoma formation, PE and CRS/HIPEC and minor postoperative complications were common in our EOCRC cohort. Despite this, the 5-year absolute survival rate was acceptable. Thus, an aggressive surgical approach in EOCRC patients at a quaternary referral centre may be feasible at the cost of greater postoperative morbidity. This information is imperative in the surgical consent and preoperative counselling of EOCRC patients and highlights the need for further research to assess the postoperative functional outcomes and quality of life of EOCRC patients.

Genome-wide association studies and Mendelian randomization analyses provide insights into the causes of early-onset colorectal cancer

BACKGROUND

The incidence of early-onset colorectal cancer (EOCRC; diagnosed <50 years of age) is rising globally; however, the causes underlying this trend are largely unknown. CRC has strong genetic and environmental determinants, yet common genetic variants and causal modifiable risk factors underlying EOCRC are unknown. We conducted the first EOCRC-specific genome-wide association study (GWAS) and Mendelian randomization (MR) analyses to explore germline genetic and causal modifiable risk factors associated with EOCRC.

PATIENTS AND METHODS

We conducted a GWAS meta-analysis of 6176 EOCRC cases and 65 829 controls from the Genetics and Epidemiology of Colorectal Cancer Consortium (GECCO), the Colorectal Transdisciplinary Study (CORECT), the Colon Cancer Family Registry (CCFR), and the UK Biobank. We then used the EOCRC GWAS to investigate 28 modifiable risk factors using two-sample MR.

RESULTS

We found two novel risk loci for EOCRC at 1p34.1 and 4p15.33, which were not previously associated with CRC risk. We identified a deleterious coding variant (rs36053993, G396D) at polyposis-associated DNA repair gene MUTYH (odds ratio 1.80, 95% confidence interval 1.47-2.22) but show that most of the common genetic susceptibility was from noncoding signals enriched in epigenetic markers present in gastrointestinal tract cells. We identified new EOCRC-susceptibility genes, and in addition to pathways such as transforming growth factor (TGF) β, suppressor of Mothers Against Decapentaplegic (SMAD), bone morphogenetic protein (BMP) and phosphatidylinositol kinase (PI3K) signaling, our study highlights a role for insulin signaling and immune/infection-related pathways in EOCRC. In our MR analyses, we found novel evidence of probable causal associations for higher levels of body size and metabolic factors-such as body fat percentage, waist circumference, waist-to-hip ratio, basal metabolic rate, and fasting insulin-higher alcohol drinking, and lower education attainment with increased EOCRC risk.

CONCLUSIONS

Our novel findings indicate inherited susceptibility to EOCRC and suggest modifiable lifestyle and metabolic targets that could also be used to risk-stratify individuals for personalized screening strategies or other interventions.

Cancer Incidence Database, 2001-2020

(1) Background: While prior data showed an increasing incidence of colorectal cancer (CRC) in young adults, the contribution of adenocarcinoma (ADC) and neuroendocrine tumors (NETs) to this trend is not well studied. Therefore, we conducted a comparative analysis of the incidence rates and time trends of colorectal ADC and NETs in young adults (aged 24-54) using the United States Cancer Statistics (USCS) database. (2) Methods: Age-adjusted CRC incidence rates between 2001 and 2020 were calculated and categorized by sex, histopathology, and stage at diagnosis. Annual percentage change (APC) and average APC (AAPC) were computed via joinpoint regression utilizing weighted Bayesian information criteria to generate the simplest trend. Pairwise comparative analysis of ADC and NETs was conducted using tests of identicalness and parallelism. (3) Results: In this study, 514,875 patients were diagnosed with early-onset-CRC between 2001 and 2020 (54.8% men). While CRC incidence was significantly increased, including both ADC (448,670 patients) and NETs (36,205 patients), a significantly greater increase was seen for NETs (AAPC = 2.65) compared to ADC (AAPC = 0.91), with AAPC difference = 1.73 (p = 0.01) and non-identical non-parallel trends (p-values < 0.001). This was most notable in males (AAPC difference = 1.81, p = 0.03) and for early-stage tumors (AAPC difference = 3.56, p < 0.001). (4) Conclusions: Our study, covering ~98% of the U.S. population provides the first comparative analysis of early-onset CRC histopathological subtypes, showing that the rate of increase of NETs in young adults is much greater than that of ADC. Given that patients with NETs with malignant behavior can experience significant mortality, our findings are importance, highlighting the rapidly increasing NET incidence in young adults and encouraging early screening that can improve outcomes.

Design of a Remote Time-Restricted Eating and Mindfulness Intervention to Reduce Risk Factors Associated with Early-Onset Colorectal Cancer Development among Young Adults

Early-onset colorectal cancer (EOCRC) is defined as a diagnosis of colorectal cancer (CRC) in individuals younger than 50 years of age. While overall CRC rates in the United States (US) decreased between 2001 and 2018, EOCRC rates have increased. This research project aims to evaluate the feasibility and acceptability of Time-Restricted Eating (TRE), Mindfulness, or TRE combined with Mindfulness among young to middle-aged adults at risk of EOCRC. Forty-eight participants will be randomly assigned to one of four groups: TRE, Mindfulness, TRE and Mindfulness, or Control. Data on feasibility, adherence, and acceptability will be collected. Measures assessed at baseline and post-intervention will include body weight, body composition, dietary intake, physical activity, sleep behavior, circulating biomarkers, hair cortisol, and the gut microbiome. The effects of the intervention on the following will be examined: (1) acceptability and feasibility; (2) body weight, body composition, and adherence to TRE; (3) circulating metabolic, inflammation, and oxidative stress biomarkers; (4) intestinal inflammation; and (5) the gut microbiome. TRE, combined with Mindfulness, holds promise for stress reduction and weight management among individuals at risk of EOCRC. The results of this pilot study will inform the design and development of larger trials aimed at preventing risk factors associated with EOCRC.

The Impact of the Gut Microbiome, Environment, and Diet in Early-Onset Colorectal Cancer Development

Traditionally considered a disease common in the older population, colorectal cancer is increasing in incidence among younger demographics. Evidence suggests that populational- and generational-level shifts in the composition of the human gut microbiome may be tied to the recent trends in gastrointestinal carcinogenesis. This review provides an overview of current research and putative mechanisms behind the rising incidence of colorectal cancer in the younger population, with insight into future interventions that may prevent or reverse the rate of early-onset colorectal carcinoma.

Colorectal Cancer: Is it Still a Disease of the Elderly?

<b><br>Introduction:</b> Colorectal cancer is becoming an increasingly significant health issue, being one of the more commonly diagnosed malignancies. Colorectal tumors account for 10% of all malignant cancers in women and 12% in men. Incidence is higher in the male population, especially among younger individuals. It is commonly believed that colorectal cancer is predominantly associated with advanced age. However, colorectal surgeons, who specialize in the treatment of this type of cancer, are observing a growing number of cases among middle-aged and younger individuals.</br> <b><br>Aim:</b> The aim of our study was to investigate whether colorectal cancer still predominantly affects elderly individuals, how frequently it is diagnosed in younger patients, and whether the location of tumors in the intestines of younger patients aligns with data from elderly individuals.</br> <b><br>Materials and methods:</b> The study was conducted retrospectively and included a cohort of 1771 patients who underwent surgical procedures due to colorectal cancer between 2012 and 2015 at the Department of General and Colorectal Surgery at the Medical University of Łódź and between 2014 and 2017 at the Department of General Surgery with a Division of Surgical Oncology at the District Health Center in Brzeziny. Data were analyzed regarding the frequency of colorectal cancer occurrence by age, tumor location in different age groups, and disease stage according to age. Age groups included <40 years, 41-50 years, 51-70 years, and >70 years.</br> <b><br>Results:</b> The study encompassed a total of 1771 patients, with 988 (55.79%) being males and 783 (44.21%) females. The mean age of the patients was 65.27 11.12 years. The highest number of cases was observed in the age range of 60-70 years and 70-80 years. It was found that colorectal tumors in males more frequently occurred on the left side of the colon and rectum, while in females, they were more commonly located on the right side of the colon, which was statistically significant (P = 0.007). Younger age groups of patients (<40 years, 40-50 years) had a similar male-to-female ratio, whereas in age groups above 50 years, males significantly outnumbered females (P = 0.049). The study revealed that in the group of patients below 40 years of age, an advanced stage of colorectal cancer was significantly more common; stage D occurred over twice as often as in the 51-70 age group and over three times as often as in the >70 age group.</br> <b><br>Conclusions:</b> The incidence of colorectal cancer in Poland is steadily increasing, with a growing number of diagnoses in younger individuals. Research findings demonstrate that males, especially those in younger age groups, are at a higher risk of developing colorectal cancer. A higher disease stage is more frequently observed in younger patients, possibly due to delayed diagnosis and symptomatic treatment. Screening programs should be adjusted to the changing age groups at higher risk. Our study underlines the need to raise public awareness regarding colorectal cancer, particularly among the younger population.</br>.

Prediction of liver and lung metastases in patients with early-onset colorectal cancer by nomograms based on heterogeneous and homogenous risk factors

BACKGROUND

Identifying the risk factors for distant metastasis in early-onset colorectal cancer (EOCRC) is crucial for elucidating its etiology and facilitating preventive treatment. This study aims to characterize the variability in EOCRC incidence and discern both heterogeneous and homogeneous risk factors associated with synchronous liver, lung, and hepato-lung metastases.

METHODS

This study included patients with EOCRC enrolled in the SEER database between 2010 and 2015 and divided patients into three groups by synchronous liver, lung, and hepato-lung metastases. Each group of patients with different metastasis types was randomly assigned to the development and validation cohort in a ratio of 7:3. Logistic regression was used to analyze the heterogeneous and homogenous risk factors for synchronous liver, lung, and hepato-lung metastases in the development cohort of patients. Nomograms were built to calculate the risk of metastasis, and the receiver operating characteristic (ROC) curve and calibration curve were used to quantitatively evaluate their performance.

RESULTS

A total of 16,336 eligible patients with EOCRC were included in this study, of which 17.90% (2924/16,336) had distant metastases. The overall incidences of synchronous liver, lung, and hepato-lung metastases were 11.90% (1921/16,146), 2.42% (390/16,126), and 1.50% (241/16,108), respectively. Positive CEA values before treatment, increased lymphatic metastases, and deeper invasion of intestinal wall were positively correlated with three distant types of metastases. On the contrary, the correlation of age, ethnicity, location of primary tumor, and histologic grade among the three types was inconsistent. The ROC curve and calibration curve proved to have fine performance in predicting distant metastases of EOCRC.

CONCLUSIONS

There are significant differences in the incidence of distant metastases in EOCRC, and related risk factors are heterogeneous and homogenous. Although limited risk factors were incorporated in this study, the established nomograms indicated good predictive performance.

Clinical and pathological characteristics of early-onset colorectal cancer in South Korea

Background

Early-onset colorectal cancer (EOCRC) may differ by race and ethnicity, and recently South Korea has witnessed a surge in cases. We aimed to evaluate the clinical and pathological features of patients with EOCRC, and to determine the predictors of overall survival.

Methods

In this retrospective study, EOCRC was defined as CRC diagnosed in patients aged < 50 years, and late-onset CRC was defined as CRC diagnosed in those over 75 years of age. The clinical and pathological characteristics of patients with EOCRC were compared with late-onset CRC. We also used multivariable Cox proportional hazard models to find predictors of overall survival in patients with EOCRC.

Results

The proportion of early-onset CRC was 9.1% of 518 patients with CRC, and the clinical and pathological characteristics were similar between early-onset (n = 47) and late-onset CRC (n = 134). However, EOCRC had a preponderance for distal tumor location (70.2% vs. 50.7%, P = 0.02) and T1-2 stage disease (23.4% vs. 11.2%, P = 0.04), compared with those of late-onset CRC. Using multivariable Cox proportional hazard models, only vascular invasion (hazard ratio = 8.75, 95% confidence interval 1.139‒67.197) was found to be a risk factor for overall survival (P = 0.04) for patients with CRC.

Conclusion

EOCRC had preponderance for distal tumor location and early T-stage disease, compared with late-onset CRC. Considering the increasing incidence of EOCRC, more studies on clinical and pathological characteristics of EOCRC may be warranted.

Early-Onset Colorectal Cancer: Prevalence, Risk Factors, and Clinical Features Among Commercially Insured Adults in the United States

BACKGROUND

 The incidence of colorectal cancer (CRC) in patients younger than 50 has been rising over the last several decades, accounting for up to 25% of total cases. Despite the screening age recently being lowered to 45, a significant proportion of cases would still arise at younger ages prior to screening. Nonfamilial early-onset CRC remains a particular concern. Identification of risk factors and clinical features in this age group is needed to improve detection.

METHODS

In this retrospective cohort analysis using claims data from the Truven Health MarketScan® Commercial Claims insurance database from 2007 to 2017, patients were identified with colon and rectal cancer, compared across three age groups (ages 18-40, 40-50, and >50), and analyzed for risk factors and clinical features.

RESULTS

Female sex was more prevalent in the younger age group compared to age >50 (54% and 51.9% vs. 49.6%), with little change noted between rectal cancer age groups by sex. A higher percentage of younger patients were in the obese age groups compared with older groups for colon cancer, particularly the morbidly obese with BMI >40 (24.94%, 25.75%, and 21.34% in the three age groups). Abdominal pain was a common presenting symptom identified in the age groups <50 compared with age >50 (25% and 19% vs. 14%), along with hematochezia, weight loss, and anemia.

CONCLUSIONS

Morbid obesity and female sex may be important risk factors among patients with early-onset CRC. The presence of abdominal pain was more common among the early-onset CRC cohort.

Referral, Uptake, and Outcome of Genetic Counseling and Testing in Patients With Early-Onset Colorectal Cancer

BACKGROUND

The incidence of early-onset colorectal cancer (EOCRC) is rapidly increasing. Pathogenic germline variants (PGVs) are detected in 16% to 20% of patients who have EOCRC, highlighting a need for genetic counseling (GC) and multigene panel testing in these patients. We aimed to determine the rate of referral to GC and uptake and outcomes of germline testing in patients with EOCRC.

METHODS

We conducted a retrospective cohort study of patients aged <50 years diagnosed with colorectal cancer (CRC) from 2010 to 2019 at Cleveland Clinic. Demographic data were extracted, including age, sex, self-reported race, and family history of CRC. The proportions of patients with GC referral and completion of GC and genetic testing were investigated, and genetic testing results were analyzed. Multivariable logistic regression analysis was conducted to identify factors independently associated with GC referral and uptake.

RESULTS

A total of 791 patients with EOCRC (57% male and 43% female) were included; 62% were referred for GC, and of those who were referred, 79% completed a GC appointment and 77% underwent genetic testing. Of those who underwent testing, 21% had a PGV detected; 82% were in known CRC-associated genes, with those associated with Lynch syndrome and familial adenomatous polyposis the most common, and 11% were in other actionable genes. Referral to GC was positively associated with family history of CRC (odds ratio [OR], 2.11; 95% CI, 1.51-2.96) and more recent year of diagnosis (2010-2013 vs 2017-2019; OR, 5.36; 95% CI, 3.59-8.01) but negatively associated with older age at diagnosis (OR, 0.89; 95% CI, 0.86-0.92).

CONCLUSIONS

Referral to GC for patients with EOCRC is increasing over time; however, even in recent years, almost 25% of patients were not referred for GC. We found that 1 in 5 patients with EOCRC carry actionable PGVs, highlighting the need for health systems to implement care pathways to optimize GC referral and testing in all patients with EOCRC.

Association between antibiotic use during early life and early-onset colorectal cancer risk overall and according to polygenic risk and FUT2 genotypes

Early-onset colorectal cancer (EOCRC) has been increasing worldwide. Potential risk factors may have occurred in childhood or adolescence. We investigated the associations between early-life factors and EOCRC risk, with a particular focus on long-term or recurrent antibiotic use (LRAU) and its interaction with genetic factors. Data on the UK Biobank participants recruited between 2006 and 2010 and followed up to February 2022 were used. We used logistic regression to estimate adjusted odds ratios (ORs) and 95% confidence intervals (95% CIs) of the associations between LRAU during early life and EOCRC risk overall and by polygenic risk score (constructed by 127 CRC-related genetic variants) and Fucosyltransferase 2 (FUT2), a gut microbiota regulatory gene. We also assessed the associations for early-onset colorectal adenomas, as precursor lesion of CRC, to examine the effect of LRAU during early-life and genetic factors on colorectal carcinogenesis. A total of 113 256 participants were included in the analysis, with 165 EOCRC cases and 719 EOCRA cases. LRAU was nominally associated with increased risk of early-onset CRC (OR = 1.48, 95% CI = 1.01-2.17, P = .046) and adenomas (OR = 1.40, 95% CI = 1.17-1.68, P < .001). When stratified by genetic polymorphisms of FUT2, LRAU appeared to confer a comparatively greater risk for early-onset adenomas among participants with rs281377 TT genotype (OR = 1.10, 95% CI = 0.79-1.52, P = .587, for CC genotype; OR = 1.75, 95% CI = 1.16-2.64, P = .008, for TT genotype; Pinteraction  = .089). Our study suggested that LRAU during early life is associated with increased risk of early-onset CRC and adenomas, and the association for adenomas is predominant among individuals with rs281377 TT/CT genotype. Further studies investigating how LRAU contributes together with genetic factors to modify EOCRC risk, particularly concerning the microbiome-related pathway underlying colorectal carcinogenesis, are warranted.

Genetic insights: High germline variant rate in an indigenous African cohort with early-onset colorectal cancer

Introduction

The increase in incidence of colorectal cancer in young patients of African ancestry coupled with increased aggressiveness has warranted investigation of the heritable nature of these cancers. Only a limited number of published reports of hereditary colorectal cancer in indigenous African populations have been reported and no systematic screening of these groups has been performed previously. We aimed to investigate causative germline variants and to establish the incidence of pathogenic/likely pathogenic germline variants in the known colorectal cancer genes in indigenous African colorectal cancer patients using a next-generation sequencing (NGS) multigene panel.

Materials and methods

Patients were selected from two hospitals in Cape Town and Johannesburg, South Africa. Patients with unresolved molecular diagnosis with an age of onset below or at 60 years were selected. Germline DNA samples were analyzed using a 14-gene NGS panel on the Ion Torrent platform. Variant calling and annotation were performed, and variants were classified according to the American College of Medical Genetics and Genomics guidelines. Observed variants were verified by Sanger sequencing and/or long-range PCR.

Results

Out of 107 patients, 25 (23.4%) presented with a pathogenic/likely pathogenic germline variant (PGV). Fourteen PGVs in at least one mismatch repair (MMR) gene were identified and verified in 12 patients (11.2%). Of these MMR gene variants, five were novel. The remaining 10 PGVs were in the APC, BMPR1A, MUTYH, POLD1, and TP53 genes.

Conclusion

The high incidence of PGVs associated with early-onset colorectal cancer in indigenous African patients has important implications for hereditary colorectal cancer risk management. These findings pave the way for personalized genetic screening programs and cascade testing in South Africa. The next step would involve further screening of the unresolved cases using tools to detect copy number variation, methylation, and whole exome sequencing.

Comprehensive Analysis of Early-onset Colorectal Cancer: A Review

Early-onset colorectal cancer (CRC), which refers to CRC diagnosed in individuals below the age of 50 years, is a growing health concern that presents unique challenges in diagnosis, treatment, and long-term outcomes. Although approximately 70% of early-onset CRC cases are sporadic, with no apparent family history, approximately 25% have a familial component, and up to 20% may be associated with germline mutations, indicating a higher prevalence compared with the general population. Despite the progress in identifying the environmental, molecular, and genetic risk factors of early-onset CRC, the underlying causes for the global increase in its incidence remain unclear. This comprehensive review aims to provide a thorough analysis of early-onset CRC by examining the trends associated with its incidence, clinical and pathological characteristics, risk factors, molecular and genetic profiles, prognosis and screening strategies. By deepening our understanding of early-onset CRC, significant advances related to improving the outcomes and alleviating the burden of this disease on individuals, families, and healthcare systems can be achieved.

Noninvasive predictive models based on lifestyle analysis and risk factors for early-onset colorectal cancer

BACKGROUND

Colorectal cancer (CRC) incidence has increased among patients aged <50 years. Exploring high-risk factors and screening high-risk populations may help lower early-onset CRC (EO-CRC) incidence. We developed noninvasive predictive models for EO-CRC and investigated its risk factors.

METHODS

This retrospective multicenter study collected information on 1756 patients (811 patients with EO-CRC and 945 healthy controls) from two medical centers in China. Sociodemographic features, clinical symptoms, medical and family history, lifestyle, and dietary factors were measured. Patients from one cohort were randomly assigned (8:2) to two groups for model establishment and internal validation, and another independent cohort was used for external validation. Multivariable logistic regression, random forest, and eXtreme Gradient Boosting (XGBoost) were performed to establish noninvasive predictive models for EO-CRC. Some variables in the model influenced EO-CRC occurrence and were further analyzed. Multivariable logistic regression analysis yielded adjusted odd ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

All three models showed good performance, with areas under the receiver operator characteristic curves (AUCs) of 0.82, 0.84, and 0.82 in the internal and 0.78, 0.79, and 0.78 in the external validation cohorts, respectively. Consumption of sweet (OR 2.70, 95% CI 1.89-3.86, P < 0.001) and fried (OR 2.16, 95% CI 1.29-3.62, P < 0.001) foods ≥3 times per week was significantly associated with EO-CRC occurrence.

CONCLUSION

We established noninvasive predictive models for EO-CRC and identified multiple nongenetic risk factors, especially sweet and fried foods. The model has good performance and can help predict the occurrence of EO-CRC in the Chinese population.

Early onset colorectal cancer in Canterbury, New Zealand

BACKGROUND

The overall incidence of colorectal cancer is decreasing in much of the world, yet the incidence in those under 50 years of age is increasing (early onset colorectal cancer (EOCRC)). The reasons for this are unclear. This study was undertaken to describe the clinical, pathological and familial characteristics of patients with EOCRC and their oncological outcomes and compare this with previously published data on late onset colorectal cancer (LOCRC).

METHODS

A retrospective review of all patients diagnosed with EOCRC in Canterbury between 2010 and 2017 was conducted. Data was collected on demographics, family history, treatment, and oncologic outcomes. Kaplan-Meier survival curves were calculated to assess overall survival based on disease stage.

RESULTS

During the study period (2010-2017) there were 3340 colorectal cancers diagnosed in Canterbury, of which 201 (6%) were in patients under 50 years (range: 17-49). Of these, 87 (43.3%) were female and 125 (62.2%) were aged between 40 and 49 years. 28 (13.9%) were associated with hereditary conditions. Of the 201 patients, 139 (69.2%) had rectal or left-sided cancers. 142 (70.6%) patients presented with either stage 3 or 4 disease and the 5-year overall survival by stage was 79.1% and 14.4%, respectively.

CONCLUSION

EOCRC is increasing and usually presents as distal left sided cancers, and often at an advanced stage. They do not appear to have the common risk factors of family history or inherited pre-disposition for colorectal cancer. Planning by healthcare providers for this epidemiological change is imperative in investigating symptomatic patients under 50 and optimizing early detection and prevention.

Clinico-Pathological Features, Outcomes and Impacts of COVID-19 Pandemic on Patients with Early-Onset Colorectal Cancer: A Single-Institution Experience

BACKGROUND

The rising incidence of colorectal cancer (CRC) among young patients is alarming. We aim to characterize the clinico-pathological features and outcomes of patients with early-onset CRC (EOCRC), as well as the impacts of COVID-19 pandemic.

METHODS

We included all patients with pathologically confirmed diagnoses of CRC at Hospital Universitario La Paz from October 2016 to December 2021. The EOCRC cut-off age was 50 years old.

RESULTS

A total of 1475 patients diagnosed with CRC were included, eighty (5.4%) of whom had EOCRC. Significant differences were found between EOCRC and later-onset patients regarding T, N stage and metastatic presentation at diagnosis; perineural invasion; tumor budding; high-grade tumors; and signet ring cell histology, with all issues having higher prevalence in the early-onset group. More EOCRC patients had the RAS/ BRAF wild type. Chemotherapy was administered more frequently to patients with EOCRC. In the metastatic setting, the EOCRC group presented a significantly longer median OS. Regarding the COVID-19 pandemic, more patients with COVID-19 were diagnosed with metastatic disease (61%) in the year after the lockdown (14 March 2020) than in the pre-pandemic EOCRC group (29%).

CONCLUSIONS

EOCRC is diagnosed at a more advanced stage and with worse survival features in localized patients. More patients with EOCRC were diagnosed with metastatic disease in the year after the COVID-19 pandemic lockdown. The long-term consequences of COVID-19 are yet to be determined.

Early-Onset Colorectal Cancer: Current Insights

Over the past decade, the incidence of colorectal cancer has increased in individuals under the age of 50 years. Meanwhile, the incidence has gradually decreased in the older population. As described herein, we reviewed the available literature to summarize the current landscape of early-onset colorectal cancer, including risk factors, clinicopathological presentation, genetic makeup of patients, and management. Currently, early-onset colorectal cancer is treated similarly as late-onset colorectal cancer, yet the available literature shows that early-onset colorectal cancer is more aggressive and different, and this remains a significant unmet need. A detailed understanding of early-onset colorectal cancer is needed to identify risk factors for the increased incidence and tailor treatments accordingly.

The analysis between clinicopathological aspect of early-onset vs. late-onset colorectal cancer and mortality rate: a cross-sectional study

Early-onset colorectal cancer (CRC) has different clinical and pathological characteristics compared with late-onset CRC. Mortality rate as a postoperative outcome is a patient's postoperative outcome considered based on the state of life or death. The objective of this research is to analyse the comparison between clinicopathological aspect of early-onset vs. late-onset CRC as well as their correlation with the mortality rate in Indonesia to support global data.

Material and methods

The authors performed a case-control study on 170 subjects with CRC from November 2021 to November 2022 in a Tertiary Hospital in Bandung. Data were extracted from electronic medical records CRC Registry. Bivariate and correlation analyses were used to analyse the difference between variables using IBM SPSS 24.0. P less than 0.05 was considered statistically significant.

Results

Anaemia and tumour location variables were significantly different in the early-onset group compared with the late-onset group (P<0.001). It was also found that anaemia (P<0.001), pathological features (P<0.001), and tumour location (P=0.013) had significantly low correlation with onset of CRC (r=0.325; r=0.397; r=0.342, respectively).

Conclusion

There is no statistically significant correlation between the clinicopathological features of CRC in both onset and mortality rates in this study.

Causes of death among early-onset colorectal cancer population in the United States: a large population-based study

Background

Early-onset colorectal cancer (EOCRC) has an alarmingly increasing trend and arouses increasing attention. Causes of death in EOCRC population remain unclear.

Methods

Data of EOCRC patients (1975-2018) were extracted from the Surveillance, Epidemiology, and End Results database. Distribution of death was calculated, and death risk of each cause was compared with the general population by calculating standard mortality ratios (SMRs) at different follow-up time. Univariate and multivariate Cox regression models were utilized to identify independent prognostic factors for overall survival (OS).

Results

The study included 36,013 patients, among whom 9,998 (27.7%) patients died of colorectal cancer (CRC) and 6,305 (17.5%) patients died of non-CRC causes. CRC death accounted for a high proportion of 74.8%-90.7% death cases within 10 years, while non-CRC death (especially cardiocerebrovascular disease death) was the major cause of death after 10 years. Non-cancer death had the highest SMR in EOCRC population within the first year after cancer diagnosis. Kidney disease [SMR = 2.10; 95% confidence interval (CI), 1.65-2.64] and infection (SMR = 1.92; 95% CI, 1.48-2.46) were two high-risk causes of death. Age at diagnosis, race, sex, year of diagnosis, grade, SEER stage, and surgery were independent prognostic factors for OS.

Conclusion

Most of EOCRC patients died of CRC within 10-year follow-up, while most of patients died of non-CRC causes after 10 years. Within the first year after cancer diagnosis, patients had high non-CRC death risk compared to the general population. Our findings help to guide risk monitoring and management for US EOCRC patients.

The mortality risk in patients with early onset colorectal cancer: the role of comorbidities

The global incidence of early-onset colorectal cancer (EO-CRC) is increasing. Although the mortality rate is relatively stable, some comorbidities have been associated with a higher mortality rate. This study estimated the mortality risk in patients with EO-CRC with various comorbidities using real-world data to identify the high-risk group using Cox proportional regression for overall and cancer-specific mortality. The incidence rate of EO-CRC significantly increased from 6.04 per 100,000 population in 2007 to 12.97 per 100,000 population in 2017. The five-year overall mortality rate was 101.50 per 1000 person year and the cancer-specific mortality rate was 94.12 per 1000 person year. Patients with cerebrovascular disease (CVD) had a higher mortality risk (hazard ratio (HR): 1.68; 95% confidence interval (CI): 1.25-2.28; p=0.0007). After subgroup analyses based on age, sex, clinical stage, and treatment type, patients with CVD had a higher overall mortality risk compared to non-CVD patients, except for patients undergoing surgery and chemotherapy. Patients with chronic kidney disease had a higher mortality risk in the early clinical stages (HR: 2.31; 95% CI: 1.08-4.96; p=0.0138). Patients who underwent radiotherapy had a higher overall mortality risk (HR: 1.38; 95% CI: 1.04-1.85; p=0.0285) than those without liver disease. Identifying specific comorbidity mortality risks in patients with EO-CRC allows for risk stratification when screening target groups and may lower disease mortality.

Molecular and Sociodemographic Colorectal Cancer Disparities in Latinos Living in Puerto Rico

BACKGROUND

The incidence of sporadic colorectal cancer (CRC) among individuals <50 years (early-onset CRC) has been increasing in the United States (U.S.) and Puerto Rico. CRC is currently the leading cause of cancer death among Hispanic men and women living in Puerto Rico (PRH). The objective of this study was to characterize the molecular markers and clinicopathologic features of colorectal tumors from PRH to better understand the molecular pathways leading to CRC in this Hispanic subpopulation.

METHODS

Microsatellite instability (MSI), CpG island methylator phenotype (CIMP), and KRAS and BRAF mutation status were analyzed. Sociodemographic and clinicopathological characteristics were evaluated using Chi-squared and Fisher's exact tests.

RESULTS

Of the 718 tumors analyzed, 34.2% (n = 245) were early-onset CRC, and 51.7% were males. Among the tumors with molecular data available (n = 192), 3.2% had MSI, 9.7% had BRAF, and 31.9% had KRAS mutations. The most common KRAS mutations observed were G12D (26.6%) and G13D (20.0%); G12C was present in 4.4% of tumors. A higher percentage of Amerindian admixture was significantly associated with early-onset CRC.

CONCLUSIONS

The differences observed in the prevalence of the molecular markers among PRH tumors compared to other racial/ethnic groups suggest a distinct molecular carcinogenic pathway among Hispanics. Additional studies are warranted.

Integrated multi-omics approach to distinct molecular characterization and classification of early-onset colorectal cancer

Incidence of early-onset colorectal cancer (EOCRC), defined by a diagnosed age under 50 years, is increasing, but its heterogeneous etiologies that differ from general CRC remain undetermined. We initially characterize the genome, epigenome, transcriptome, and proteome of tumors from 79 patients in a Chinese CRC cohort. Data for an additional 126 EOCRC subjects are obtained from the International Cancer Genome Consortium Chinese cohort and The Cancer Genome Atlas European cohort. We observe that early-onset tumors have a high tumor mutation burden; increased DNA repair features by mutational signature 3 and multi-layer pathway enrichments; strong perturbations at effects of DNA methylation and somatic copy-number alteration on gene expression; and upregulated immune infiltration as hot tumors underlying immunophenotypes. Notably, LMTK3 exhibits ancestral mutation disparity, potentially being a functional modulator and biomarker that drives molecular alterations in EOCRC development and immunotherapies. This integrative omics study provides valuable knowledge for precision oncology of CRC.

Epidemiology of overall and early-onset serrated polyps versus conventional adenomas in a colonoscopy screening cohort

Serrated polyps (SPs) are precursors to one-third of colorectal cancers (CRCs), with histological subtypes: hyperplastic polyps (HPs), sessile serrated lesions (SSLs) and traditional serrated adenomas (TSAs). The incidence of early-onset CRC before the age of 50 is increasing, with limited understanding of SPs in younger cohorts. Using a large colonoscopy-based cohort, we characterized epidemiologic profiles of SP subtypes, compared to conventional adenomas, with secondary analysis on early-onset polyps. Ninety-four thousand four hundred and twenty-seven patients underwent screening colonoscopies between 2010 and 2018. Demographic, endoscopic and histopathologic characteristics of each polyp subtype were described. High-risk polyps included SSLs ≥10 mm/with dysplasia and conventional adenomas ≥10 mm/with tubulovillous/villous histology/high-grade dysplasia. We examined polyp prevalence with age and compared early- (age < 50) and late-onset polyps (age ≥ 50). Eighteen thousand one hundred and twenty-five patients had SPs (4357 SSLs, 15 415 HPs, 120 TSAs) and 26 699 had conventional adenomas. High-risk SSLs were enriched in the ascending colon (44.1% vs 2.6-35.8% for other locations; P < .003). Early- and late-onset SPs had similar subsite distribution. Early-onset conventional adenomas were more enriched in the distal colon/rectum (51.8% vs 43.4%, P < .001). Multiple conventional adenomas were more represented in late-onset groups (40.8% vs 33.8%, P < .001), with no difference in SSLs. The prevalence of conventional adenomas/high-risk conventional adenomas increased continuously with age, whereas the prevalence of SSLs/high-risk SSLs was stable from age 40 years onwards. A higher proportion of women were diagnosed with early-onset than late-onset SSLs (62.9% vs 57.6%, P = .03). Conventional adenomas, SSLs, early- and late-onset polyps have distinct epidemiology. The findings have implications for improved colonoscopy screening and surveillance and understanding the etiologic heterogeneity of CRC.

Cancer statistics for American Indian and Alaska Native individuals, 2022: Including increasing disparities in early onset colorectal cancer

American Indian and Alaska Native (AIAN) individuals are diverse culturally and geographically but share a high prevalence of chronic illness, largely because of obstacles to high-quality health care. The authors comprehensively examined cancer incidence and mortality among non-Hispanic AIAN individuals, compared with non-Hispanic White individuals for context, using population-based data from the National Cancer Institute, the Centers for Disease Control and Prevention, and the North American Association of Central Cancer Registries. Overall cancer rates among AIAN individuals were 2% higher than among White individuals for incidence (2014 through 2018, confined to Purchased/Referred Care Delivery Area counties to reduce racial misclassification) but 18% higher for mortality (2015 through 2019). However, disparities varied widely by cancer type and geographic region. For example, breast and prostate cancer mortality rates are 8% and 31% higher, respectively, in AIAN individuals than in White individuals despite lower incidence and the availability of early detection tests for these cancers. The burden among AIAN individuals is highest for infection-related cancers (liver, stomach, and cervix), for kidney cancer, and for colorectal cancer among indigenous Alaskans (91.3 vs. 35.5 cases per 100,000 for White Alaskans), who have the highest rates in the world. Steep increases for early onset colorectal cancer, from 18.8 cases per 100,000 Native Alaskans aged 20-49 years during 1998 through 2002 to 34.8 cases per 100,000 during 2014 through 2018, exacerbated this disparity. Death rates for infection-related cancers (liver, stomach, and cervix), as well as kidney cancer, were approximately two-fold higher among AIAN individuals compared with White individuals. These findings highlight the need for more effective strategies to reduce the prevalence of chronic oncogenic infections and improve access to high-quality cancer screening and treatment for AIAN individuals. Mitigating the disparate burden will require expanded financial support of tribal health care as well as increased collaboration and engagement with this marginalized population.

Colorectal cancer statistics, 2023

Colorectal cancer (CRC) is the second most common cause of cancer death in the United States. Every 3 years, the American Cancer Society provides an update of CRC statistics based on incidence from population-based cancer registries and mortality from the National Center for Health Statistics. In 2023, approximately 153,020 individuals will be diagnosed with CRC and 52,550 will die from the disease, including 19,550 cases and 3750 deaths in individuals younger than 50 years. The decline in CRC incidence slowed from 3%-4% annually during the 2000s to 1% annually during 2011-2019, driven partly by an increase in individuals younger than 55 years of 1%-2% annually since the mid-1990s. Consequently, the proportion of cases among those younger than 55 years increased from 11% in 1995 to 20% in 2019. Incidence since circa 2010 increased in those younger than 65 years for regional-stage disease by about 2%-3% annually and for distant-stage disease by 0.5%-3% annually, reversing the overall shift to earlier stage diagnosis that occurred during 1995 through 2005. For example, 60% of all new cases were advanced in 2019 versus 52% in the mid-2000s and 57% in 1995, before widespread screening. There is also a shift to left-sided tumors, with the proportion of rectal cancer increasing from 27% in 1995 to 31% in 2019. CRC mortality declined by 2% annually from 2011-2020 overall but increased by 0.5%-3% annually in individuals younger than 50 years and in Native Americans younger than 65 years. In summary, despite continued overall declines, CRC is rapidly shifting to diagnosis at a younger age, at a more advanced stage, and in the left colon/rectum. Progress against CRC could be accelerated by uncovering the etiology of rising incidence in generations born since 1950 and increasing access to high-quality screening and treatment among all populations, especially Native Americans.

Immune Microenvironment in Sporadic Early-Onset versus Average-Onset Colorectal Cancer

The incidence of left-sided colon and rectal cancer in young people are increasing worldwide, but its causes are poorly understood. It is not clear if the tumor microenvironment is dependent on age of onset, and little is known about the composition of tumor-infiltrating T cells in early-onset colorectal cancer (EOCRC). To address this, we investigated T-cell subsets and performed gene expression immune profiling in sporadic EOCRC tumors and matched average-onset colorectal cancer (AOCRC) tumors. Left-sided colon and rectal tumors from 40 cases were analyzed; 20 EOCRC (<45 years) patients were matched 1:1 to AOCRC (70-75 years) patients by gender, tumor location, and stage. Cases with germline pathogenic variants, inflammatory bowel disease or neoadjuvant-treated tumors were excluded. For T cells in tumors and stroma, a multiplex immunofluorescence assay combined with digital image analysis and machine learning algorithms was used. Immunological mediators in the tumor microenvironment were assessed by NanoString gene expression profiling of mRNA. Immunofluorescence revealed no significant difference between EOCRC and AOCRC with regard to infiltration of total T cells, conventional CD4⁺ and CD8⁺ T cells, regulatory T cells, or γδ T cells. Most T cells were located in the stroma in both EOCRC and AOCRC. Immune profiling by gene expression revealed higher expression in AOCRC of the immunoregulatory cytokine IL-10, the inhibitory NK cell receptors KIR3DL3 and KLRB1 (CD161), and IFN-a7 (IFNA7). In contrast, the interferon-induced gene IFIT2 was more highly expressed in EOCRC. However, in a global analysis of 770 tumor immunity genes, no significant differences could be detected. T-cell infiltration and expression of inflammatory mediators are similar in EOCRC and AOCRC. This may indicate that the immune response to cancer in left colon and rectum is not related to age of onset and that EOCRC is likely not driven by immune response deficiency.

Telomere Length as a New Risk Marker of Early-Onset Colorectal Cancer

Early-onset colorectal cancer (EOCRC; age younger than 50 years) incidence has been steadily increasing in recent decades worldwide. The need for new biomarkers for EOCRC prevention strategies is undeniable. In this study, we aimed to explore whether an aging factor, such as telomere length (TL), could be a useful tool in EOCRC screening. The absolute leukocyte TL from 87 microsatellite stable EOCRC patients and 109 healthy controls (HC) with the same range of age, was quantified by Real Time Quantitative PCR (RT-qPCR). Then, leukocyte whole-exome sequencing (WES) was performed to study the status of the genes involved in TL maintenance (hTERT, TERC, DKC1, TERF1, TERF2, TERF2IP, TINF2, ACD, and POT1) in 70 sporadic EOCRC cases from the original cohort. We observed that TL was significantly shorter in EOCRC patients than in healthy individuals (EOCRC mean: 122 kb vs. HC mean: 296 kb; p < 0.001), suggesting that telomeric shortening could be associated with EOCRC susceptibility. In addition, we found a significant association between several SNPs of hTERT (rs79662648), POT1 (rs76436625, rs10263573, rs3815221, rs7794637, rs7784168, rs4383910, and rs7782354), TERF2 (rs251796 and rs344152214), and TERF2IP (rs7205764) genes and the risk of developing EOCRC. We consider that the measurement of germline TL and the status analysis of telomere maintenance related genes polymorphisms at early ages could be non-invasive methods that could facilitate the early identification of individuals at risk of developing EOCRC.

Total calcium, dairy foods and risk of colorectal cancer: a prospective cohort study of younger US women

BACKGROUND

Although colorectal cancer (CRC) incidence is declining among adults aged ≥65 years, CRC incidence in younger adults has been rising. The protective role of calcium in colorectal carcinogenesis has been well established, but evidence is lacking on whether the association varies by age at diagnosis. We investigated the association between total calcium intake and risk of overall CRC and CRC before age 55 years.

METHODS

In the Nurses' Health Study II (1991-2015), 94 205 women aged 25-42 years at baseline were included in the analysis. Diet was assessed every 4 years through validated food frequency questionnaires. Multivariable-adjusted hazard ratios (HRs) and 95% CIs for CRC were estimated using the Cox proportional hazards model.

RESULTS

We documented 349 incident CRC cases during 2 202 604 person-years of follow-up. Higher total calcium intake was associated with a reduced risk of CRC. Compared with those with <750 mg/day of total calcium intake, the HR of CRC was 0.61 (95% CI, 0.38-0.97) for those who consumed ≥1500 mg/day (P for trend = 0.01). The HR per 300 mg/day increase was 0.85 (95% CI, 0.76-0.95). There was a suggestive inverse association between total calcium intake and CRC before age 55 years (HR per 300 mg/day increase, 0.87; 95% CI, 0.75-1.00), suggesting the importance of calcium intake in the younger population.

CONCLUSIONS

In a cohort of younger women, which reflects the birth cohorts, time periods and age ranges paralleling the recent rise in CRC, higher calcium intake was associated with a decreased risk of CRC.

Dietary Factors and Early-Onset Colorectal Cancer in the United States-an Ecologic Analysis

BACKGROUND

Incidence of early-onset colorectal cancer (EOCRC; e.g., diagnosed before age 50) in the United States has increased substantially since the 1990s but the underlying reasons remain unclear.

METHODS

We examined the ecologic associations between dietary factors and EOCRC incidence in adults aged 25-49 during 1977-2016 in the United States, using negative binomial regression models, accounting for age, period, and race. The models also incorporated an age-mean centering (AMC) approach to address potential confounding by age. We stratified the analysis by sex and computed incidence rate ratio (IRR) for each study factor. Study factor data (for 18 variables) came from repeated national surveys; EOCRC incidence data came from the Surveillance Epidemiology, and End Results Program.

RESULTS

Results suggest that confounding by age on the association with EOCRC likely existed for certain study factors (e.g., calcium intake), and that AMC can alleviate the confounding. EOCRC incidence was positively associated with smoking [IRR (95% confidence interval (CI): 1.17 (1.10-1.24) for men; 1.15 (1.09-1.21) for women] and alcohol consumption [IRR (95% CI), 1.08 (1.04-1.12) for men; 1.08 (1.04-1.11) for women]. No strong associations were found for most other study factors (e.g., fiber and calcium).

CONCLUSIONS

Alcohol consumption was positively associated with EOCRC and has increased among young adults since the 1980s, which may have contributed to the EOCRC incidence increases since the 1990s. The AMC approach may help alleviate age confounding in similar ecologic analyses.

IMPACT

Increases in alcohol consumption may have contributed to the recent increases in colorectal cancer incidence among young adults. See related commentary by Ni et al., p. 164.

Disease Burden of Total and Early-Onset Colorectal Cancer in China from 1990 to 2019 and Predictions of Cancer Incidence and Mortality

Background

Understanding the temporal trends in the epidemiology of colorectal cancer (CRC) and early-onset CRC (EOCRC) in China is essential for policymakers to develop appropriate strategies to reduce the CRC burden.

Methods

The prevalence, incidence, mortality, years of life lived with disability (YLDs), years of life lost (YLLs), and disability-adjusted life years (DALYs) of CRC were obtained from the Global Burden of Disease (GBD) Study 2019. The incidence and mortality of CRC over the next 25 years were predicted.

Results

From 1990 to 2019, the prevalence, incidence, and mortality of total CRC and EOCRC significantly increased in males, with milder trends in females. In 2019, the number of people living with CRC (or EOCRC) in China was approximately 3.4 (0.59) million, which was over seven (five) times higher than that in 1990. The DALYs, YLDs, and YLLs moderately increased from 1990 to 2019 in both sexes. The age-standardized mortality rate (ASMR) for females has shown a stable trend in total CRC, and a downward trend in EOCRC since 2000. While the ASMR for males showed increasing trends in total CRC and EOCRC. In 2019, the highest incidence, prevalence, YLDs, YLLs, and DALYs were all observed in the 65 to 69 age group, while the highest mortality was in the 70 to 74. By 2044, the incidence and deaths of CRC are expected to reach 1310 thousand and 484 thousand, respectively. For EOCRC, the incidence will peak at about 101 thousand around 2034, and the mortality will continuously decrease to a nadir at about 18 thousand around 2044.

Conclusion

Although the age-standardized incidence and mortality of total CRC and EOCRC in China will reach a plateau, the number of incident cases and deaths of CRC have been increasing in the last three decades and will continue to increase in the next 25 years.

Autoimmune and Metabolic Diseases and the Risk of Early-Onset Colorectal Cancer, a Nationwide Nested Case-Control Study

Incidence of early-onset (<50 years) colorectal cancer (EOCRC) is increasing in developed countries. The aim was to investigate autoimmune and metabolic conditions as risk factors for EOCRC. In a nationwide nested case-control study, we included all EOCRC cases in Sweden diagnosed during 2007-2016, together with controls, matched for birth year, sex, and county. Information on exposure of autoimmune or metabolic disease was collected from the National Patient Register and Prescribed Drugs Registry. Hazard ratios (HR) as measures of the association between EOCRC and the exposures were estimated using conditional logistic regression. In total, 2626 EOCRC patients and 15,756 controls were included. A history of metabolic disease nearly doubled the incidence hazard of EOCRC (HR 1.82, 95% CI 1.66-1.99). A sixfold increased incidence hazard of EOCRC (HR 5.98, 95% CI 4.78-7.48) was seen in those with inflammatory bowel disease (IBD), but the risk increment decreased in presence of concomitant metabolic disease (HR 3.65, 95% CI 2.57-5.19). Non-IBD autoimmune disease was not statistically significantly associated with EOCRC. IBD and metabolic disease are risk factors for EOCRC and should be considered in screening guidelines.

Prognostic value of systemic immune inflammation index and geriatric nutrition risk index in early-onset colorectal cancer

Background

Systemic nutritional and inflammatory markers, which are easy to measure are associated with the progression and prognosis of many cancers. Nevertheless, among the various available indicators, optimal prognostic indicators for patients with early-onset colorectal cancer have not been identified. Therefore, the aim of this study was to identify optimal nutritional and inflammatory markers for early-onset colorectal cancer and examine the relationship between systemic nutritional and inflammatory markers before treatment and survival in patients with early-onset colorectal cancer.

Methods

We retrospectively collected data from 236 eligible patients with early-onset colorectal cancer. Area under the prognostic curve (AUC) and concordance index (C-index) were used to compare seven systemic nutritional and inflammatory markers to identify the optimal inflammatory immune markers. Univariate and multivariate COX regression analyses were used to evaluate the prognostic value of indicators in the total study population and different subgroups.

Results

The AUC and C-index showed that the systemic immune inflammation index (SII) and geriatric nutrition risk index (GNRI) had higher prognostic values than other systemic nutritional and inflammatory indicators. Compared with patients in the low SII group, those in the high SII group had lower overall survival (HR, 4.42, 95% CI, 2.36-8.27, p = 0.000). Compared with patients in the high GNRI group, those in the low GNRI group had lower overall survival (HR, 0.33, 95% CI, 0.19-0.56, p = 0.000). SII was negatively associated with GNRI (R = -0.3, p < 0.001), and both were correlated with the tumor stage.

Conclusion

SII and GNRI are suitable nutritional and inflammatory factors for predicting OS in patients with early-onset colorectal cancer; high SII and low GNRI were correlated with worse prognoses. Identifying the high inflammatory state and low nutritional state of patients before surgery and conducting active and timely therapeutic interventions could improve patient prognosis.

FIT-based risk-stratification model effectively screens colorectal neoplasia and early-onset colorectal cancer in Chinese population: a nationwide multicenter prospective study

No fully validated risk-stratification strategies have been established in China where colonoscopies resources are limited. We aimed to develop and validate a fecal immunochemical test (FIT)-based risk-stratification model for colorectal neoplasia (CN); 10,164 individuals were recruited from 175 centers nationwide and were randomly allocated to the derivation (n = 6776) or validation cohort (n = 3388). Multivariate logistic analyses were performed to develop the National Colorectal Polyp Care (NCPC) score, which formed the risk-stratification model along with FIT. The NCPC score was developed from eight independent predicting factors and divided into three levels: low risk (LR 0–14), intermediate risk (IR 15–17), and high risk (HR 18–28). Individuals with IR or HR of NCPC score or FIT+ were classified as increased-risk individuals in the risk-stratification model and were recommended for colonoscopy. The IR/HR of NCPC score showed a higher prevalence of CNs (21.8%/32.8% vs. 11.0%, P < 0.001) and ACNs (4.3%/9.2% vs. 2.0%, P < 0.001) than LR, which was also confirmed in the validation cohort. Similar relative risks and predictive performances were demonstrated between non-specific gastrointestinal symptoms (NSGS) and asymptomatic cohort. The risk-stratification model identified 73.5% CN, 82.6% ACN, and 93.6% CRC when guiding 52.7% individuals to receive colonoscopy and identified 55.8% early-onset ACNs and 72.7% early-onset CRCs with only 25.6% young individuals receiving colonoscopy. The risk-stratification model showed a good risk-stratification ability for CN and early-onset CRCs in Chinese population, including individuals with NSGS and young age.

Time Trend and Association of Early-Onset Colorectal Cancer with Diverticular Disease in the United States: 2010-2021

Purpose: To examine time trends of incidence rates of EOCRC from 2010 to 2021 among patients with and without diverticular disease and to examine whether diverticular disease is associated with increased risk of EOCRC. Methods: This is a retrospective cohort study of 46,179,351 young adults aged 20−49, including 298,117 with diverticular disease. We examined yearly incidence rate of first diagnosis of EOCRC from 2010 through 2021 among patients with and without diverticular disease. The 5-year risk of EOCRC among patients with pre-existing diverticular disease was compared to propensity-matched patients without diverticular disease and EOCRC and odds ratio (OR) and 95% confidence interval (CI) were calculated. Results: The yearly incidence rate of new diagnosis of EOCRC (measured as new cases per 100,000 people per year) in young adults with pre-existing diverticular disease increased from 100 in 2010 to 402 in 2021, 4−6 times higher than in those without diverticular disease (24 in 2010 to 77 in 2021) (p < 0.001). Patients with diverticular disease were at higher risk for EOCRC than those without (OR: 1.76, 95% CI: 1.40−2.32). Conclusion: The incidence of EOCRC continuously increased from 2010 through 2021 in patients with and without diverticular disease and was 4−6 times higher among patients with diverticular disease. Patients with pre-existing diverticular disease were at a significantly increased risk for EOCRC.

Persistent Disparities in Colorectal Cancer Screening: A Tell-Tale Sign for Implementing New Guidelines in Younger Adults

BACKGROUND

In May 2021, the U.S. Preventive Services Task Force began recommending initiating colorectal cancer screening at age 45 (vs. 50) years.

METHODS

We estimated prevalence of colorectal cancer screening (by colonoscopy, sigmoidoscopy, CT colonography, or stool-based tests) in adults ages 50 to 75 years using data from the National Health Interview Survey in 2000, 2003, 2005, 2008, 2010, 2013, 2015, and 2018. For each survey year, we estimated prevalence by age, race/ethnicity, educational attainment, family income, and health insurance. We also compared increases in prevalence of screening from 2000 to 2018 in 5-year age groups (50-54, 55-59, 60-64, 65-69, and 70-75 years).

RESULTS

Overall, prevalence of colorectal cancer screening increased from 36.7% in 2000 to 66.1% in 2018. Screening prevalence in 2018 was lowest for age 50 to 54 years (47.6%), Hispanics (56.5%), Asians (57.1%), and participants with less than a high school degree (53.6%), from low-income families (56.6%), or without insurance (39.7%). Increases in prevalence over time differed by five-year age group. For example, prevalence increased from 28.2% in 2000 to 47.6% in 2018 (+19.4%; 95% CI, 13.1-25.6) for age 50 to 54 years but from 46.4% to 78.0% (+31.6%; 95% CI, 25.4%-37.7%) for age 70 to 75 years. This pattern was consistent across race/ethnicity, educational attainment, family income, and health insurance.

CONCLUSIONS

Prevalence of colorectal cancer screening remains low in adults ages 50 to 54 years.

IMPACT

As new guidelines are implemented, care must be taken to ensure screening benefits are realized equally by all population groups, particularly newly eligible adults ages 45 to 49 years. See related commentary by Brawley, p. 1671.

Transcriptome Analyses Identify Deregulated MYC in Early Onset Colorectal Cancer

Despite a global decrease in colorectal cancer (CRC) incidence, the prevalence of early-onset colorectal cancer (EOCRC), or those occurring in individuals before the age of 50, has steadily increased over the past several decades. When compared to later onset colorectal cancer (LOCRC) in individuals over 50, our understanding of the genetic and molecular underpinnings of EOCRCs is limited. Here, we conducted transcriptomic analyses of patient-matched normal colonic segments and tumors to identify gene expression programs involved in carcinogenesis. Amongst differentially expressed genes, we found increased expression of the c-MYC proto-oncogene (MYC) and its downstream targets in tumor samples. We identified tumors with high and low differential MYC expression and found patients with high-MYC tumors were older and overweight or obese. We also detected elevated expression of the PVT1 long-non-coding RNA (lncRNA) in most tumors and found gains in copy number for both MYC and PVT1 gene loci in 35% of tumors evaluated. Our transcriptome analyses indicate that EOCRC can be sub-classified into groups based on differential MYC expression and suggest that deregulated MYC contributes to CRCs that develop in younger patients.

Recurrent NOMO1 Gene Deletion Is a Potential Clinical Marker in Early-Onset Colorectal Cancer and Is Involved in the Regulation of Cell Migration

Simple Summary

The incidence of EOCRC (age < 50 years at diagnosis) with unknown causes is rising worldwide, necessitating the mechanistical analysis of its molecular basis. The NOMO1 gene is deleted in a high number of EOCRC tumors compared to LOCRC. In this work, we aimed to test the NOMO1 gene mutational profile in EOCRC tumors and to characterize the effect of NOMO1 loss in different CRISPR/cas9-edited cell lines, as well as in murine models. Here, we show that the NOMO1 gene can be inactivated not only by deletion but also by pathogenic mutations in EOCRC. Our results indicate that NOMO1 loss could be a passenger mutation in the development of EOCRC, although it contributes significantly to colon cancer cell migration.

Abstract

The incidence of early-onset colorectal cancer (EOCRC; age younger than 50 years) has been progressively increasing over the last decades globally, with causes unexplained. A distinct molecular feature of EOCRC is that compared with cases of late-onset colorectal cancer, in EOCRC cases, there is a higher incidence of Nodal Modulator 1 (NOMO1) somatic deletions. However, the mechanisms of NOMO1 in early-onset colorectal carcinogenesis are currently unknown. In this study, we show that in 30% of EOCRCs with heterozygous deletion of NOMO1, there were pathogenic mutations in this gene, suggesting that NOMO1 can be inactivated by deletion or mutation in EOCRC. To study the role of NOMO1 in EOCRC, CRISPR/cas9 technology was employed to generate NOMO1 knockout HCT-116 (EOCRC) and HS-5 (bone marrow) cell lines. NOMO1 loss in these cell lines did not perturb Nodal pathway signaling nor cell proliferation. Expression microarrays, RNA sequencing, and protein expression analysis by LC–IMS/MS showed that NOMO1 inactivation deregulates other signaling pathways independent of the Nodal pathway, such as epithelial–mesenchymal transition and cell migration. Significantly, NOMO1 loss increased the migration capacity of CRC cells. Additionally, a gut-specific conditional NOMO1 KO mouse model revealed no subsequent tumor development in mice. Overall, these findings suggest that NOMO1 could play a secondary role in early-onset colorectal carcinogenesis because its loss increases the migration capacity of CRC cells. Therefore, further study is warranted to explore other signalling pathways deregulated by NOMO1 loss that may play a significant role in the pathogenesis of the disease.

Early onset metastatic colorectal cancer in patients receiving panitumumab-based upfront strategy: Overall and sex-specific outcomes in the Valentino trial

Anti-EGFRs plus doublet chemotherapy is considered the optimal upfront option for RAS/BRAF wild-type left-sided metastatic colorectal cancer (mCRC). Early-onset (EO) mCRC has an increasing incidence and its prognostic/predictive role and management is debatable. We performed a post hoc analysis of Valentino study, that randomized RAS wild-type mCRC patients to two panitumumab-based maintenance regimens after FOLFOX/panitumumab induction. We assessed the safety and efficacy outcomes in patients stratified for age (<50/≥50 years old). We assessed progression-free survival (PFS), overall survival (OS), response rate (ORR), rate of treatment-related and panitumumab-related adverse events (AEs) and quality of life (QoL). In 229 patients enrolled, 35 (15%) had EO mCRC, with a higher rate of female sex (P = .020) and lower rate of primary tumor resection (P = .001). Median PFS and OS were 10.9 vs 10.8 months (P = .593) and 28.1 vs 27.5 months (P = .865) in patients <50 and ≥50 years old, respectively, with no significant impact of maintenance arm. ORR and disease control rate were 74% vs 65% (P = .337) and 97% vs 81% (P = .013) in patients <50 or ≥50 years old. In younger patients, a trend for increased chemotherapy-related AEs (peculiarly anemia) was shown, while significantly decreased EGFR-related hypomagnesemia and increased skin rash were reported. No significant differences in treatment intensity or QoL were observed. In patients with EO mCRC and RAS wild-type status, we found no differences in terms of survival outcomes based on age when selecting maintenance strategies. Management of treatment-related AEs should consider the differential toxicity profile of age and sex.

Early-onset colorectal cancer: why it should be high on our list of differentials

Background

Early‐onset colorectal cancer (EOCRC) (<50 years) incidence has increased in Australia and worldwide. However, the diagnosis of EOCRC is often delayed. Recent research has discovered some differences from later‐onset colorectal cancer (LOCRC) (>50 years). An awareness of the unique features of EOCRC is crucial to reduce time from symptom onset to diagnosis.

Methods

A literature search was conducted on electronic databases (MEDLINE, EMBASE and Cochrane Library) using the search terms “early onset colorectal cancer” or “young onset colorectal cancer.”

Results

The American Cancer Society has reduced the colorectal cancer screening initiation age to 45 for average‐risk adults whilst screening programmes in the United Kingdom and Australia remain unchanged with initiation at 60 and 50, respectively. Exposures resulting in dysbiosis (obesity, westernised diet, alcohol, antibiotic and sugar‐sweetened beverage consumption) have been linked with increased EOCRC risk. EOCRC is often left‐sided presenting with rectal bleeding, altered bowel habit and constitutional symptoms. EOCRC is more commonly sporadic than hereditary, harbouring different genetic mutations than LOCRC. Comparative survival outcomes of EOCRC and LOCRC are conflicting with studies suggesting either better or poorer survival. Young patients better tolerate treatment‐related toxicities, which may account for their improved survival despite comparatively advanced stages and poorer histopathological features at diagnosis.

Conclusion

Current EOCRC literature is limited by American‐focused datasets and heterogenous EOCRC definitions and study designs (the greatest strength of evidence exists for EOCRC risk factor studies comprised of large retrospective cohorts). There is minimal research into the quality of life and surgical outcomes of EOCRC patients, and this area warrants further investigation.

Age-period-cohort effects in utilization of diagnostic procedures leading to incidental colorectal cancer detection

BACKGROUND AND AIM

Despite the overall decrease in colorectal cancer (CRC) incidence, a small but constant rise has been recently observed in people younger than 50 years across several countries. This phenomenon can be explained by environmental or lifestyle factors, but it may also be partially justified by an increasing tendency in younger cohorts to undertake diagnostic procedures that may lead to CRC incidental diagnosis.

METHODS

We performed an age-period-cohort analysis on 1 815 694 diagnostic procedures undertook by the population of the City of Milan, served by the Agency for Health Protection of Milan, between 1999 and 2018. We considered all instances of colonoscopy, rectoscopy, fecal occult blood test (FOBT) and ultrasonography. We stratified by gender, nationality and quintile of socioeconomic deprivation.

RESULTS

Incidence of utilization rose with age for all procedures but rectoscopy; there was a marked increase from 2005 to 2010 for FOBT and colonoscopy. A strong all-procedures cohort effect was observed, greater for FOBT and colonoscopy. A steady increase of diagnostic procedures utilization started in cohorts born in the late 1950s, with a relative effect rising from 0.91 [95% confidence interval (CI) 0.90-0.92] for the 1950 cohort to 5.03 (95% CI, 4.58-5.48) for the 1990 one.

CONCLUSION

We found a growing tendency in younger cohorts to undertake diagnostic procedures, explainable by inappropriate access to endoscopic procedures, that can lead to an incidental diagnosis of CRC. This finding may at least partially explain the observed rising incidence of early-onset CRC.

Constipation Misperception: Could It Be Familial Adenomatosis Polyposis?

Colorectal cancer is the second leading cause of cancer deaths in the United States. Familial adenomatosis polyposis (FAP) is a rare cause of colorectal cancer. The United States Preventive Services Task Force (USPSTF) recommends screening for colorectal cancer in average-risk, asymptomatic adults aged 50 to 75 years. While age is the most important risk factor, we need to consider the family history of colorectal cancer. FAP is a rare cause of colorectal cancer, leading to high morbidity and mortality if undetected and undiagnosed. It is easy to overlook the family history in a busy primary care clinic with limited patient encounter times. Clinicians mustn't forget this important piece of information as it can give leads for further patient evaluation. We present a case report of a 21-year-old male who presented to our clinic to establish primary care and with vague abdominal complaints. Still, the concerning family history of early onset colon cancer in his half-sister raised red flags and directed us to further evaluate. Further evaluation revealed our patient, in fact, had FAP.

Racial disparities negatively impact outcomes in early-onset colorectal cancer independent of socioeconomic status

BACKGROUND

The incidence of colorectal cancer (CRC) in patients under age 50 is rising for unclear reasons. We examined the effects of socioeconomic factors on outcomes for patients with early-onset CRC compared to late-onset CRC.

METHODS

Patients with CRC from 2004 to 2015 in the National Cancer Database were included and categorized by age (under or over 50 years). Differences in demographic and socioeconomic factors, disease characteristics, and survival outcomes between early-onset versus late-onset CRC patients were assessed by Chi-squared test and Cox models.

RESULTS

The study population included 1,061,204 patients, 108,058 (10.2%) of whom were under age 50. The proportion of patients diagnosed under age 50 increased over time: 9.4% in 2004-2006, 10.1% in 2007-2009, 10.5% in 2010-2012, and 10.7% in 2013-2015 (p < 0.0001). Early-onset CRC patients were more likely to be Black (15.1% vs. 11.3%) or Hispanic (8.6% vs. 4.6%) and to present with stage 4 disease (24.9% vs. 17.0%), p < 0.0001 for all. Black patients had the worst median OS (58.3 months) compared to White (67.0 months), Hispanic (91.6 months), or Asian (104.9 months) patients, p < 0.0001. Within the subgroup of early-onset CRC patients with private insurance, Black patients had worse OS compared to White patients, even in communities with higher income and education status.

CONCLUSIONS

Early-onset CRC continues to increase. Patients with early-onset CRC are more likely to be Black or Hispanic and to present with stage 4 cancer. Early-onset Black patients showed worse OS compared to White patients in all income subgroups, even with private insurance.

Racial Disparities and Sex Differences in Early- and Late-Onset Colorectal Cancer Incidence, 2001-2018

Background

Colorectal cancer (CRC) incidence rates have increased in younger individuals worldwide. We examined the most recent early- and late-onset CRC rates for the US.

Methods

Age-standardized incidence rates (ASIR, per 100,000) of CRC were calculated using the US Cancer Statistics Database’s high-quality population-based cancer registry data from the entire US population. Results were cross-classified by age (20-49 [early-onset] and 50-74 years [late-onset]), race/ethnicity (non-Hispanic White, non-Hispanic Black, Hispanic, American Indian/Alaskan Native, Asian/Pacific Islander), sex, anatomic location (proximal, distal, rectal), and histology (adenocarcinoma, neuroendocrine).

Results

During 2001 through 2018, early-onset CRC rates significantly increased among American Indians/Alaskan Natives, Hispanics, and Whites. Compared to Whites, early-onset CRC rates are now 21% higher in American Indians/Alaskan Natives and 6% higher in Blacks. Rates of early-onset colorectal neuroendocrine tumors have increased in Whites, Blacks, and Hispanics; early-onset colorectal neuroendocrine tumor rates are 2-times higher in Blacks compared to Whites. Late-onset colorectal adenocarcinoma rates are decreasing, while late-onset colorectal neuroendocrine tumor rates are increasing, in all racial/ethnic groups. Late-onset CRC rates remain 29% higher in Blacks and 15% higher in American Indians/Alaskan Natives compared to Whites. Overall, CRC incidence was higher in men than women, but incidence of early-onset distal colon cancer was higher in women.

Conclusions

The early-onset CRC disparity between Blacks and Whites has decreased, due to increasing rates in Whites—rates in Blacks have remained stable. However, rates of colorectal neuroendocrine tumors are increasing in Blacks. Blacks and American Indians/Alaskan Natives have the highest rates of both early- and late-onset CRC.

Impact

Ongoing prevention efforts must ensure access to and uptake of CRC screening for Blacks and American Indians/Alaskan Natives.

Assessing Presenting Symptoms, Co-Morbidities, and Risk Factors for Mortality in Underserved Patients With Non-Hereditary Early-Onset Colorectal Cancer

Background The presenting symptoms and co-morbidities contributing to mortality in young patients (age < 50 years old) with colorectal cancer (CRC) are poorly understood. We reviewed these features in our patient population with non-hereditary early-onset CRC (EO-CRC). Study aim This study aimed to assess characteristics of patients with a diagnosis of non-hereditary EO-CRC, including presenting symptoms and metabolic disorders contributing to mortality in underserved areas of southwest Virginia. Methods In this retrospective observational study, we selected patients aged 18-50 years with a diagnosis of non-hereditary EO-CRC from 2008 to 2016 at Carilion Roanoke Memorial Hospital. The electronic medical record was queried to identify demographic data, medical history, histopathology results, lab values, and mortality. The cumulative risks of symptoms and co-morbid metabolic disorders was estimated using Kaplan-Meier curves. Results We identified 139 patients with non-hereditary EO-CRC (mean age 41.6 ± 6.9 years). Almost half of these patients were obese (BMI > 30), 30.9% had a diagnosis of hypertension, 29% had hyperlipidemia (HLD), and 17.35% had diabetes mellitus type 2 (DM2). Diagnosis was delayed by 4.5 months from initial presentation, and 17% had advanced disease (stage III/IV). Also, 68.5% of patients were symptomatic with one to three symptoms, most commonly with rectal bleeding (45.3%). The chronicity of HLD (≥5 years) was associated with reduced survival in our patients with EO-CRC. The survival of females with multiple metabolic disorders was reduced compared to females with a single metabolic disorder. Conclusions Multiple symptoms, chronic HLD, and female gender with multiple metabolic disorders were factors associated with poor outcomes in non-hereditary EO-CRC patients.

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.

Clinicopathologic Factors Associated with Mismatch Repair Status Among Filipino Patients with Young-Onset Colorectal Cancer

Introduction

Young-onset colorectal cancer is recognized as a distinct disease that may be sporadic or hereditary in nature. Microsatellite instability testing is recommended as a routine procedure in evaluating colorectal cancer specimens, especially in young-onset disease, because of implications in management. Immunohistochemistry of mismatch repair proteins serves as an inexpensive alternative to microsatellite instability testing with the added advantage of monitoring protein expression levels that may suggest underlying genetic or epigenetic alterations. This descriptive study aimed to determine the frequencies of proficient and deficient mismatch repair status among Filipino young-onset colorectal cancer patients, and to investigate their clinicopathologic profile.

Methods

Tumor tissues were prospectively collected from patients from two tertiary hospitals in the Philippines. Patients of age ≤45 years with resected adenocarcinoma of the colon or rectum were recruited.

Results

Seventy-seven out of 124 patients had tumor samples sent for immunohistochemistry. Of these, 61 samples (79%) were found to have proficient status while 16 samples (21%) had deficient status. Mismatch repair protein deficiencies, when present, more commonly involved MSH2 and MSH6 (9%) rather than MLH1 and PMS2 (5%). The deficient group had a mean age of 37.1 years and a female preponderance (56.25%), presenting as locally advanced ascending or descending colon tumors with mucinous histology in half of the population. The mismatch repair proficient group presented as locally advanced rectal and sigmoid tumors but with fewer mucinous adenocarcinomas (26.2%) compared to the deficient group. In both the mismatch repair proficient and deficient patients with family history reports, most did not have any known relative with cancer (75.4% and 68.75%, respectively).

Conclusion

This is the first attempt to perform mismatch repair testing among young-onset colorectal cancer patients in the Philippines and to gather data on their clinicopathologic characteristics. However, the limited sample size precludes conclusive results for the associations of mismatch repair with clinicopathologic features.