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

Early Detection and Age-Comparative Analysis of Colorectal Cancer Screening: Insights from the Turkish Population

BACKGROUND

This study aimed to evaluate the diagnostic yield of colonoscopy in asymptomatic individuals aged 45-49 years compared with those aged 50-54 years in a Turkish population, providing insights into region-specific screening strategies.

METHODS

This retrospective multicenter study was conducted across three tertiary endoscopy units in Turkey. Screening colonoscopy data from 3943 asymptomatic individuals aged 45-54 years between 2018 and 2023 were analyzed. The patients were stratified into two groups: 45-49 years (Group 1) and 50-54 years (Group 2). Demographic characteristics, polyp size, histological features, and prevalence of early-onset advanced colorectal neoplasia (EAO-aCRN) were assessed.

RESULTS

A total of 3943 patients were included, with 862 in Group 1 (45-49 years) and 3081 in Group 2 (50-54 years). The polyp detection rate was 16.6% in Group 1 and 22.9% in Group 2 (p < 0.001). The adenoma detection rates were 10.8% and 13.9% in Groups 1 and 2, respectively (p = 0.018). The advanced polyp detection rates were 3.2% and 7.3% in Groups 1 and 2, respectively (p < 0.001). Mean polyp size was 6.5 ± 5.1 mm in Group 1 and 8.8 ± 8.4 mm in Group 2 (p < 0.001). The mean number of polyps per patient was 1.5 ± 0.8 in Group 1 and 1.9 ± 1.6 in Group 2 (p = 0.023). Advanced neoplasia was detected in 16.6% of Group 1 patients compared with 22.9% of Group 2 patients (p < 0.001).

CONCLUSIONS

While CRC screening at age 45 demonstrated lower detection rates of polyps and advanced neoplasia than at age 50, the higher prevalence of EAO-CRN among 45-49-year-olds in Turkey underscores the importance of early screening in high-risk populations. Tailored regional strategies incorporating individual risk factors are crucial for optimizing CRC prevention policies.

The Impact of Age on Preferences for Colorectal Cancer Surveillance Strategies: Are Fecal Immunochemical Tests FIT for Surveillance?

INTRODUCTION

Individuals with a known risk of colorectal cancer (CRC) are recommended regular surveillance colonoscopies. Alternative surveillance strategies incorporating fecal immunochemical tests (FIT) may improve colonoscopy resource utilization and be more appropriate for those with a lower risk of CRC, particularly younger adults. This study compared younger (< 50 years) and older (≥ 50 years) adults' preferences for different CRC surveillance strategies.

METHODS

Eight hundred individuals enrolled in a colonoscopy-based surveillance program were invited to complete a survey assessing CRC surveillance preferences. Preferences for colonoscopy frequency and the acceptability of two alternative protocols were assessed: (1) providing FIT between colonoscopies, and (2) a FIT-only strategy where colonoscopy would only be required after a positive FIT result.

RESULTS

A total of 102 younger (median age 41.4 years, 67.6% female) and 187 older (median age 68.5 years, 49.2% female) adults completed the survey. Surveillance preferences did not significantly vary by age group; most respondents preferred colonoscopies more often than their current frequency (< 50 years: 54.1%; ≥ 50 years: 58.1%). Although most participants (< 50 years: 91.2%; ≥ 50 years: 93.0%) agreed that FIT is important to complete between surveillance colonoscopies, only a small proportion were comfortable with FIT-only surveillance replacing colonoscopies (< 50 years: 27.5%; ≥ 50 years: 37.4%). Fear of CRC was a significant predictor of preferences for more frequent surveillance incorporating FIT in younger, but not older, adults.

CONCLUSION

Many individuals with an elevated risk of CRC wanted more frequent surveillance, regardless of their age. Extending surveillance colonoscopy intervals using FIT may be a more acceptable method of reducing colonoscopy frequency rather than utilizing a FIT-only approach.

TRIAL REGISTRATION

This study was prospectively registered with the Australian New Zealand Clinical Trials Registry (ACTRN #12619001743156).

A decade-long study on pathological distinctions of resectable early versus late onset colorectal cancer and optimal screening age determination

The incidence of Early-Onset Colorectal Cancer (EOCRC) is increasing. However, the prognosis of EOCRC compared to Late-Onset Colorectal Cancer (LOCRC), and the ideal age for initial colorectal cancer (CRC) screening are not clear. In this study, we identified the pathological differences between the groups and determined the optimal screening age for CRC patients. We included 10,172 patients diagnosed with CRC from January 2011 to December 2021 in this study. Survival differences were compared by plotting Kaplan-Meier survival curves and conducting landmark analysis. Additionally, the diagnostic age of CRC patients was analyzed using age cumulative curves. Compared to LOCRC patients, EOCRC patients had a higher proportion of deficient mismatch repair (dMMR) and more advanced TNM staging (P < 0.05). The five-year survival of EOCRC patients was significantly better than that of LOCRC patients (P < 0.05). Laparoscopic surgery improved the long-term survival of EOCRC patients. Proficient mismatch repair (pMMR) favored the long-term survival of EOCRC patients. The survival rate of EOCRC patients at TNM stages I and II was higher than that of LOCRC patients at the same stages (P < 0.05). The age cumulative curve showed a substantial increase in the number of CRC patients at 40 years. The long-term prognosis of EOCRC patients is better than that of LOCRC patients, especially among those with pMMR, stages I-II, and who undergo laparoscopic surgery. For people with a high risk of cancer, such as a family history of cancer and poor lifestyle habits, the starting age for CRC screening should be 40 years.

Risk Factors Associated with Advanced Colorectal Neoplasia in Adults Younger than Age 45

BACKGROUND

Colorectal cancer (CRC) is rising in young adults between ages 20 to 49 years. CRC screening is endorsed for average-risk individuals beginning at ages 45 to 49 years. Targeting screening for individuals <45 years may be warranted if risk factors for advanced neoplasia can be identified.

AIM

To identify factors associated with advanced colorectal neoplasia in adults aged <45 years.

METHOD

Individuals ages 18 to 44 years who underwent colonoscopy at Cleveland Clinic between 2011 and 2021 with ≥1 advanced neoplasm (AN) were included. Patients with inflammatory bowel disease or inherited CRC syndromes were excluded. Demographics, comorbidities, family history of CRC, and colonoscopy indication were obtained. Patients with a normal colonoscopy constituted the control group. A multivariable logistic regression model was used to investigate the relationship between clinical variables and the presence of advanced colorectal neoplasia.

RESULTS

In all, 13,006 patients were included, of which 651 (5%) patients had AN: 404 (62%) with tubular adenoma ≥10 mm, 29 (4.5%) tubular adenoma with high-grade dysplasia, 210 (32%) tubulovillous adenomas, 27 (4%) traditional serrated adenomas, 82 (13%) sessile serrated lesions ≥10 mm, 7(2%) sessile serrated lesions with dysplasia, and 29 (4.4%) patients had a CRC. Factors associated with AN were older age (means 38.5 vs. 36.6 y), history of smoking, diabetes, non-White race, higher body mass index (29.9 vs. 28.5 kg/m 2 ), and lower vitamin D (27.6 vs. 32.2 ng/dl), all P <0.001. In the reduced multivariable model, factors associated with AN included tobacco use (OR 2.026 (current vs. never, P <0.0001), age (OR increase by 1.06 per year, P <0.0001), male gender (OR 1.476, P <0.0001), family history of CRC (OR 3.91, P <0.0001), aspirin use (1.31, P =0.035), and diabetes (OR 2.106, P 0.001).

CONCLUSION

Increasing age, male gender, exposure to tobacco, family history of CRC, diabetes, and aspirin use were independently associated with advanced neoplasia in adults younger than 45. Targeted early screening to young adults with these risk factors may be justified. Large collaborative prospective studies are needed to validate our findings.

Risk of metachronous neoplasia in early-onset colorectal cancer: meta-analysis

BACKGROUND

Metachronous colorectal cancer refers to patients developing a second colorectal neoplasia diagnosed at least 6 months after the initial cancer diagnosis, excluding recurrence. The aim of this systematic review is to assess the incidence of metachronous colorectal cancer in early-onset colorectal cancer (defined as age at diagnosis of less than 50 years) and to identify risk factors.

METHODS

This is a systematic review and meta-analysis performed following the PRISMA statement and registered on PROSPERO. The literature search was conducted in PubMed and Embase. Only studies involving patients with early-onset colorectal cancer (less than 50 years old) providing data on metachronous colorectal cancer were included in the analysis. The primary endpoint was the risk of metachronous colorectal cancer in patients with early-onset colorectal cancer. Secondary endpoints were association with Lynch syndrome, family history and microsatellite instability.

RESULTS

Sixteen studies met the inclusion criteria. The incidence of metachronous colorectal cancer was 2.6% (95% c.i. 2.287-3.007). The risk of developing metachronous colorectal cancer in early-onset colorectal cancer versus non-early-onset colorectal cancer patients demonstrated an OR of 0.93 (95% c.i. 0.760-1.141). The incidence of metachronous colorectal cancer in patients with Lynch syndrome was 18.43% (95% c.i. 15.396-21.780), and in patients with family history 10.52% (95% c.i. 5.555-17.659). The proportion of metachronous colorectal cancer tumours in the microsatellite instability population was 19.7% (95% c.i. 13.583-27.2422).

CONCLUSION

The risk of metachronous colorectal cancer in patients with early-onset colorectal cancer is comparable to those with advanced age, but it is higher in patients with Lynch syndrome, family history and microsatellite instability. This meta-analysis demonstrates the need to personalize the management of patients with early-onset colorectal cancer according to their risk factors.

Metachronous Colorectal Neoplasia in Young Adults With Advanced Neoplasia Undergoing Colonoscopy: A Comparison of Risk by Age <45 Years Versus 45 to 49 Years

BACKGROUND

The risk of metachronous advanced colorectal neoplasia (mACRN) in young adults with advanced lesions at baseline colonoscopy is not well defined.

AIMS

To examine the risk for (mACRN) in adults <50 years old who had advanced neoplasia (AN) at baseline colonoscopy and determine factors associated with mACRN in these patients.

METHOD

Patients 18 to 49 years of age with ≥1 AN [tubular adenoma (TA) ≥10 mm or with villous features or high-grade dysplasia (HGD), sessile serrated lesion (SSL) ≥10 mm or with dysplasia, traditional serrated adenoma (TSA)] on baseline colonoscopy between 2011 and 2021 who had surveillance colonoscopy >6 months after their baseline examination were included. Outcomes were assessed based on age at baseline colonoscopy, <45 years versus 45 to 49 years, and by follow-up colonoscopy findings: (1) normal, (2) nonadvanced neoplasia (NAN), and (3) AN.

RESULTS

Three hundred sixty-six patients with AN underwent ≥1 surveillance colonoscopy: 310 (84.7%) <45 years versus 56 (15.3%) 45 to 49 years. The mean follow-up time was longer for the <45-year-olds versus the 45 to 49-year-olds (43±26.4 vs. 28.4±12.8 mo respectively, P<0.001). The absolute risk of mACRN was 13.5% in the <45 age group versus 16.1% in the 45 to 49 age group, P=0.28. The 3-year cumulative incidence rates of mACRN were comparable for patients <45 and 45 to 49 years old: 10% (95% CI: 10% to 42%) versus 20% (95% CI: 7% to 15%), P=0.065. BMI was the only risk factor associated with mACRN OR 1.045 [95% CI (1.001 to 1.09)].

CONCLUSIONS

In our cohort of patients <50 years old with AN at baseline, mACRN occurred at a similar rate to that reported by guidelines in 50 years and older, suggesting that current recommended post polypectomy surveillance is appropriate for this age group. BMI was independently associated with mACRN. Future studies should examine how weight management in patients with high BMI mitigates the recurrence of advanced neoplasia.

Efficacy and safety of Shenbai Granules for recurrent colorectal adenoma: A multicenter randomized controlled trial

BACKGROUND

Colorectal adenoma is benign glandular tumor of colon, the precursor of colorectal cancer. But no pharmaceutical medication is currently available to treat and prevent adenomas.

PURPOSE

To evaluate efficacy of Shenbai Granules, an herbal medicine formula, in reducing the recurrence of adenomas.

STUDY DESIGN

This multicenter, randomized, double-blind, placebo-controlled clinical trial was conducted by eight hospitals in China.

METHODS

Patients who had received complete polypectomy and were diagnosed with adenomas within the recent 6 months were randomly assigned (1:1) to receive either Shenbai granules or placebo twice a day for 6 months. An annual colonoscopy was performed during the 2-year follow-up period. The primary outcome was the proportion of patients with at least one adenoma detected in the modified intention-to-treat (mITT) population during follow-up for 2 years. The secondary outcomes were the proportion of patients with sessile serrated lesions and other specified polypoid lesions. The data were analyzed using logistic regression.

RESULTS

Among 400 randomized patients, 336 were included in the mITT population. We found significant differences between treatment and placebo groups in the proportion of patients with at least one recurrent adenoma (42.5 % vs. 58.6 %; OR, 0.47; 95 % CI, 0.29-0.74; p = 0.001) and sessile serrated lesion (1.8 % vs. 8.3 %; OR, 0.20; 95 % CI, 0.06-0.72; p = 0.01). There was no significant difference in the proportion of patients developing polypoid lesions (70.7 % vs. 77.5 %; OR, 1.43; 95 % CI, 0.88-2.34; p = 0.15) or high-risk adenomas (9.0 % vs. 13.6 %; OR, 0.63; 95 % CI, 0.32-1.25; p = 0.18).

CONCLUSION

Shenbai Granules significantly reduced the recurrence of adenomas, indicating that they could be an effective option for adenomas. Future studies should investigate its effects in larger patient populations and explore its mechanism of action to provide more comprehensive evidence for the use of Shenbai Granules in adenoma treatment.

Colon Polyp Surveillance: Separating the Wheat From the Chaff

One goal of colorectal cancer (CRC) screening is to prevent CRC incidence by removing precancerous colonic polyps, which are detected in up to 50% of screening examinations. Yet, the lifetime risk of CRC is 3.9%-4.3%, so it is clear that most of these individuals with polyps would not develop CRC in their lifetime. It is, therefore, a challenge to determine which individuals with polyps will benefit from follow-up, and at what intervals. There is some evidence that individuals with advanced polyps, based on size and histology, benefit from intensive surveillance. However, a large proportion of individuals will have small polyps without advanced histologic features (ie, "nonadvanced"), where the benefits of surveillance are uncertain and controversial. Demand for surveillance will further increase as more polyps are detected due to increased screening uptake, recent United States recommendations to expand screening to younger individuals, and emergence of polyp detection technology. We review the current understanding and clinical implications of the natural history, biology, and outcomes associated with various categories of colon polyps based on size, histology, and number. Our aims are to highlight key knowledge gaps, specifically focusing on certain categories of polyps that may not be associated with future CRC risk, and to provide insights to inform research priorities and potential management strategies. Optimization of CRC prevention programs based on updated knowledge about the future risks associated with various colon polyps is essential to ensure cost-effective screening and surveillance, wise use of resources, and inform efforts to personalize recommendations.

Clinical characteristics of symptomatic young patients with colonic adenomas

BACKGROUND

The incidence of colonic adenomas and colorectal cancer has been on the rise among young patients. In this study, we aimed to describe the characteristics of young patients (<50 years) with adenomatous polyps and to characterize those polyps. We also aimed to determine appropriate surveillance intervals for young patients.

METHODS

We performed a retrospective chart review of patients <50 years of age who had polypectomy of 1 or more adenomatous polyps on colonoscopy between 2008 and 2021. Patient demographics, colonoscopy indication and polyp characteristics were obtained from the chart. Timing and findings on surveillance colonoscopies were recorded.

RESULTS

A total of 610 patients were included: mean age 42.9±5.9 years, 61% males, body mass index 27.5±4.7 kg/m2, and over 50% smokers. The most common indications were abdominal pain (23.3%), rectal bleeding (22.3%), and change in bowel habits (17.6%). Almost half of the patients who had adenomas (299) were younger than 45 years. Tubular adenoma was the most frequently encountered type of polyp (571; 93.6%). Mean polyp size was 1.1±0.9 cm. The most common location of adenomas was the sigmoid colon (41%). Of patients with adenomas, 156 (26%) had surveillance colonoscopy within 2.9±2.3 years; 74 patients (47.4%) were found to have new adenomas.

CONCLUSIONS

Patients aged <50 years with colonic adenomas were mostly males, overweight, and smokers. Further adenomas were found in 47% of surveillance colonoscopies, and most were encountered within 5 years. High rates of recurrent adenomas in people <50 years of age may warrant frequent surveillance.

Metabolic-associated fatty liver disease is associated with colorectal adenomas in young and older Korean adults

BACKGROUND AND AIMS

Given that the majority of colorectal cancers (CRCs) develop from high-risk adenomas, identifying risk factors for high-risk adenomas is important. The relationship between metabolic dysfunction-associated fatty liver disease (MAFLD) and the risk of colorectal adenoma in young adults remains unclear. We aimed to evaluate this relationship in adults <50 (younger) and ≥50 (older) years of age.

METHODS

This cross-sectional study included 184 792 Korean adults (80% <50 years of age) who all underwent liver ultrasound and colonoscopy. Participants were grouped into those with and without MAFLD and classified by adenoma presence into no adenoma, low-risk adenoma, or high-risk adenoma (defined as ≥3 adenomas, any ≥10 mm, or adenoma with high-grade dysplasia/villous features).

RESULTS

The prevalence of low- and high-risk adenomas among young and older adults was 9.6% and 0.8% and 22.3% and 4.8%, respectively. MAFLD was associated with an increased prevalence of low- and high-risk adenomas in young and older adults. Young adults with MAFLD had a 1.30 (95% CIs 1.26-1.35) and 1.40 (1.23-1.59) times higher prevalence of low- and high-risk adenomas, respectively, compared to those without MAFLD. These associations were consistent even in lean adults (BMI < 23 kg/m2 ) and those without a family history of CRC.

CONCLUSIONS

MAFLD is associated with an increased prevalence of low- and high-risk adenomas in Korean adults, regardless of age or obesity status. Whether reducing metabolic risk factors, such as MAFLD, reduces the risk of precancerous lesions and ultimately reduces the risk of early-onset CRC requires further investigation.

Factors influencing age at onset of colorectal polyps and benefit-finding after polypectomy

Screening, followed by colonoscopic polypectomy, has been widely performed in China. However, factors influencing age at onset of colorectal polyps and benefit-finding after polypectomy have been insufficiently studied or ignored. A total of 152 patients with colorectal polyps first detected in First Affiliated Hospital of Huzhou University from July to September 2022 were enrolled in this study. We selected 11 factors associated with the risk of colorectal polyps, including gender, body mass index, occupational stress, education level, income satisfaction, smoking, alcohol consumption, exercise frequency, diet, family history and polyp characteristics. Benefit-finding after polypectomy was obtained by follow-up for 142 of these patients. Multivariate linear regression analysis showed that being overweight (i.e., body mass index ≥25 kg/m2), higher education level, lower exercise frequency, and refrigerated food preference were associated with early-onset colorectal polyps. Patients with a preference for pickled food and age ≥50 years at first colorectal polyp detection had lower benefit findings after colonoscopic polypectomy. Colorectal polyps may develop earlier in people who are overweight, well-educated, exercise less, and prefer refrigerated food. In addition, patients who prefer pickled food and age at onset ≥50 years have lower benefit-finding requiring more attention in future colonoscopy follow-ups.

Risk of Incident and Fatal Colorectal Cancer After Young-Onset Adenoma Diagnosis: A National Cohort Study

INTRODUCTION

Colorectal cancer (CRC) incidence and mortality rates are increasing in adults aged <50 years. Young-onset adenoma (YOA)-adenoma detected in adults younger than 50 years-may signify increased CRC risk, but this association has not been widely studied. Our aim was to compare the risk of incident and fatal CRC in adults aged <50 years with YOA diagnosis compared with those with a normal colonoscopy.

METHODS

We conducted a cohort study of US Veterans aged 18-49 years who received colonoscopy between 2005 and 2016. The primary exposure of interest was YOA. Primary outcomes included incident and fatal CRC. We used Kaplan-Meier curves to calculate cumulative incident and fatal CRC risk and Cox models to examine relative CRC risk.

RESULTS

The study cohort included 54,284 Veterans aged <50 years exposed to colonoscopy, among whom 13% (n = 7,233) had YOA at start of follow-up. Cumulative 10-year CRC incidence was 0.11% (95% confidence interval [CI]: 0.00%-0.27%) after any adenoma diagnosis, 0.18% (95% CI: 0.02%-0.53%) after advanced YOA diagnosis, 0.10% (95% CI: 0.00%-0.28%) after nonadvanced adenoma diagnosis, and 0.06% (95% CI: 0.02%-0.09%) after normal colonoscopy. Veterans with advanced adenoma had 8-fold greater incident CRC risk than those with normal colonoscopy (hazard ratio: 8.0; 95% CI: 1.8-35.6). Across groups, no differences in fatal CRC risk were observed.

DISCUSSION

Young-onset advanced adenoma diagnosis was associated with 8-fold increased incident CRC risk compared with normal colonoscopy. However, cumulative CRC incidence and mortality at 10 years among individuals with either young onset non-advanced or advanced adenoma diagnosis were both relatively low.

Discovery of extracellular vesicle-delivered miR-185-5p in the plasma of patients as an indicator for advanced adenoma and colorectal cancer

BACKGROUND

We aimed to evaluate whether extracellular vesicles (EV)-derived microRNAs (miRNAs) can be used as biomarkers for advanced adenoma (AA) and colorectal cancer (CRC).

METHODS

We detected the changes in the plasma EV-delivered miRNA profiles in healthy donor (HD), AA patient, and I-II stage CRC patient groups using miRNA deep sequencing assay. We performed the TaqMan miRNA assay using 173 plasma samples (two independent cohorts) from HDs, AA patients, and CRC patients to identify the candidate miRNA(s). The accuracy of candidate miRNA(s) in diagnosing AA and CRC was determined using the area under the receiver-operating characteristic curve (AUC) values. Logistic regression analysis was performed to evaluate the association of candidate miRNA(s) as an independent factor for the diagnosis of AA and CRC. The role of candidate miRNA(s) in the malignant progression of CRC was explored using functional assays.

RESULTS

We screened and identified four prospective EV-delivered miRNAs, including miR-185-5p, which were significantly upregulated or downregulated in AA vs. HD and CRC vs. AA groups. In two independent cohorts, miR-185-5p was the best potential biomarker with the AUCs of 0.737 (Cohort I) and 0.720 (Cohort II) for AA vs. HD diagnosis, 0.887 (Cohort I) and 0.803 (Cohort II) for CRC vs. HD diagnosis, and 0.700 (Cohort I) and 0.631 (Cohort II) for CRC vs. AA diagnosis. Finally, we demonstrated that the upregulated expression of miR-185-5p promoted the malignant progression of CRC.

CONCLUSION

EV-delivered miR-185-5p in the plasma of patients is a promising diagnostic biomarker for colorectal AA and CRC. Trial registration The study protocol was approved by the Ethics Committee of Changzheng Hospital, Naval Medical University, China (Ethics No. 2022SL005, Registration No. of China Clinical Trial Registration Center: ChiCTR220061592).

Incidence and risk outcomes of second primary malignancy of patients with post-operative colorectal cancer

BACKGROUND AND AIMS

This study aimed to investigate the incidence and the risk factors of incidence for second primary malignancies (SPMs) onset among survivors diagnosed with colorectal cancer (CRC).

METHODS

A large population-based cohort study was performed. Data of patients diagnosed with CRC was identified and extracted from 8 cancer registries of Surveillance, Epidemiology, and End Results database from January 1990 to December 2017. The outcome of interest was percentage and common sites of SPM onset after primary CRC diagnosis. The cumulative incidence and standardize incidence rates (SIRs) were also reported. Afterwards, we estimated sub-distribution hazards ratios (SHRs) and relative risks (RRs) for SPM occurrence using multivariable competing-risk and Poisson regression models, respectively.

RESULTS

A total of 152,402 patients with CRC were included to analyze. Overall, 23,816 patients of all CRC survivors (15.6%) were reported SPM occurrence. The highest proportion of SPMs development after primary CRC diagnosis was second CRC, followed by lung and bronchus cancer among all survivors. Also, CRC survivors were more susceptible to develop second gastrointestinal cancers (GICs). Besides, pelvic cancers were analyzed with a relative high proportion among patients who received RT in comparison to those without RT. The cumulative incidence of all SPMs onset was 22.16% (95% CI: 21.82-22.49%) after near 30-year follow-up. Several factors including older age, male, married status, and localized stage of CRC were related to the high risk of SPMs onset. In treatment-specific analyses, RT was related to a higher cumulative incidence of SPMs occurrence (all SPMs: 14.08% vs. 8.72%; GICs: 2.67% vs. 2.04%; CRC: 1.01% vs. 1.57%; all p < 0.01). Furthermore, the increased risk of SPMs onset was found among patients who received RT than patients within the NRT group (SHR: 1.50, 95% CI: 1.32-1.71), p < 0.01; RR: 1.61, 95% CI: 1.45-1.79, p < 0.01).

CONCLUSION

The present study described the incidence pattern of SPM among CRC survivors and identified the risk factors of the SPM onset. RT treatment for patients diagnosed with CRC may increase the risk of SPMs occurrence. The findings suggest the need for long-term follow-up surveillance for these patients.

Delphi Initiative for Early-Onset Colorectal Cancer (DIRECt) International Management Guidelines

BACKGROUND & AIMS

Patients with early-onset colorectal cancer (eoCRC) are managed according to guidelines that are not age-specific. A multidisciplinary international group (DIRECt), composed of 69 experts, was convened to develop the first evidence-based consensus recommendations for eoCRC.

METHODS

After reviewing the published literature, a Delphi methodology was used to draft and respond to clinically relevant questions. Each statement underwent 3 rounds of voting and reached a consensus level of agreement of ≥80%.

RESULTS

The DIRECt group produced 31 statements in 7 areas of interest: diagnosis, risk factors, genetics, pathology-oncology, endoscopy, therapy, and supportive care. There was strong consensus that all individuals younger than 50 should undergo CRC risk stratification and prompt symptom assessment. All newly diagnosed eoCRC patients should receive germline genetic testing, ideally before surgery. On the basis of current evidence, endoscopic, surgical, and oncologic treatment of eoCRC should not differ from later-onset CRC, except for individuals with pathogenic or likely pathogenic germline variants. The evidence on chemotherapy is not sufficient to recommend changes to established therapeutic protocols. Fertility preservation and sexual health are important to address in eoCRC survivors. The DIRECt group highlighted areas with knowledge gaps that should be prioritized in future research efforts, including age at first screening for the general population, use of fecal immunochemical tests, chemotherapy, endoscopic therapy, and post-treatment surveillance for eoCRC patients.

CONCLUSIONS

The DIRECt group produced the first consensus recommendations on eoCRC. All statements should be considered together with the accompanying comments and literature reviews. We highlighted areas where research should be prioritized. These guidelines represent a useful tool for clinicians caring for patients with eoCRC.

The Risk of Metachronous Advanced Neoplasia After Colonoscopy in Patients Aged 40-49 Years Compared With That in Patients Aged 50-59 Years

INTRODUCTION

This study investigated the risk of metachronous advanced neoplasia (AN) after colonoscopy in individuals aged 40-49 years compared with that in individuals aged 50-59 years.

METHODS

A retrospective cohort study was performed among Kaiser Permanente Northern California members aged 40-59 years who had their first (index) colonoscopy in 2010-2013. Participants were followed up until death, disenrollment, AN on surveillance colonoscopy, or December 31, 2018. The risk for the development of AN was estimated using the Cox regression, adjusted for confounders.

RESULTS

The study included 11,374 patients (2,396 aged 40-49 years and 8,978 aged 50-59 years). When comparing the 40-49 years group with the 50-59 years group, AN was detected in 2.2% vs 4.4% ( P = 0.0003) on surveillance colonoscopy after index colonoscopy finding of no adenoma, in 4.6% vs 7.0% ( P = 0.03) after a finding of nonadvanced adenoma (NAA), and in 7.9% vs 11.7% ( P = 0.06) after a finding of advanced adenoma (AA), respectively. Compared with the 50-59 years group, the 40-49 years group had a lower risk of metachronous AN when no adenoma was detected on index colonoscopy (hazard ratio [HR] 0.58; 95% confidence interval [CI] 0.39-0.83) and no difference when NAA (HR 0.84; 95% CI 0.54-1.24) or AA (HR 0.83; 95% CI 0.51-1.31) was detected.

DISCUSSION

Compared with patients aged 50-59 years, patients aged 40-49 years may have a lower risk of developing metachronous AN when no adenoma is detected on index colonoscopy and a similar risk when NAA or AA is detected. These data suggest current surveillance colonoscopy guidelines may be applicable to patients aged 40-49 years who undergo colonoscopy.

Factors associated with the risk of colorectal neoplasia in young adults under age 40

BACKGROUND/AIMS

Recent epidemiologic studies have shown a continued increase in colorectal cancer incidence among younger adults. Little is known about the factors that contribute to the development of young-onset colorectal neoplasia (CRN).

METHODS

A cross-sectional analysis was performed for individuals younger than 40 years who underwent colonoscopy in Seoul St. Mary's Hospital and its affiliated health screening center. High-risk CRN was defined as adenoma or sessile serrated lesion ≥ 10 mm, with three or more adenomas, villous histology, high grade dysplasia, or carcinoma.

RESULTS

Of these 13,621 included participants, 2,023 (14.9%) had one and more CRN. Young patients with CRN tended to be elderly, male, obese, smoker, having a habit of drinking, and having comorbidities such as hypertension, dyslipidemia, diabetes, and chronic kidney disease. In a multivariate analysis adjusted for age, sex, obesity, smoking status, and alcohol intake, old age (odds ratio [OR], 1.086; 95% confidence interval [CI], 1.054 to 1.119), male sex (OR, 1.748; 95% CI, 1.247 to 2.451), obesity (OR, 1.439; 95% CI, 1.133 to 1.828), and smoking (OR, 1.654; 95% CI, 1.287 to 2.127) were independent risk factors for overall CRN. Obesity and smoking as two modifiable factors increased the risk for high-risk CRN even more than for overall CRN (OR, 1.734; 95% CI, 1.168 to 2.575 and OR, 1.797; 95% CI, 1.172 to 2.753, respectively).

CONCLUSION

Obesity and smoking were modifiable risk factors for CRN in young adults. They increased the risk for highrisk CRN even more than for overall CRN. A colonoscopy might be beneficial for young individuals with these factors.

Different lipid metabolic profiles and their associated genes in sessile serrated adenoma or polyps compared to hyperplastic polyps

The serrated pathway is important in the development of colorectal cancer; currently, knowledge about the lipid metabolism profiles of serrated lesions is limited. Clinical characteristics were compared via Pearson's chi-squared test, nonparametric Kruskal-Wallis test and ANOVA. For some missing values, the MCAR test and multiple imputations were performed. Compared to patients with HP, the rates of younger patients (<50) and male patients with SSA or SSP were increased (P<0.05). Additionally, the BMI index and triglyceride levels were increased in patients with SSA or SSP. Inversely, patients with SSA/P had lower levels of HDL (P<0.05). Interestingly, the value of uric acid and tumor size in SSA/P patients tended to be greater than those in HP patients, and the ratio of patients who smoked was also increased. Other characteristics, such as LDL, ALB, γ-GT, and the N/L ratio, were similar among the subtypes of serrated lesions. Analysis of GEO data (GSE43841) showed that 9 genes were associated with lipid metabolism, including ADRB3, DEGS2, PRKACB, SLC44A1, and CA4. PRKACB was downregulated in SSA/P tissue compared to HP tissue samples from the GSE76987 dataset and our hospital. In conclusion, compared to benign HP, lower HDL levels and higher triglyceride levels tended to occur in CRC precursor SSA/P lesions, and these factors may be associated with metabolic genomic markers, such as PRKACB.

Prevalence and Predictors of Young-Onset Colorectal Neoplasia: Insights From a Nationally Representative Colonoscopy Registry

BACKGROUND & AIMS

A disturbing increase in early-onset colorectal cancer (EOCRC) has prompted recent guidelines to recommend lowering the colorectal cancer (CRC) screening starting age from 50 to 45 years old for average-risk individuals. Little is known about the prevalence of colorectal neoplasia in individuals between 45 and 49 years old, or even younger, in the United States. We analyzed a large, nationally representative data set of almost 3 million outpatient colonoscopies to determine the prevalence of, and risk factors for, colorectal neoplasia among patients aged 18 to 54.

METHODS

Findings from high-quality colonoscopies were analyzed from AMSURG ambulatory endoscopy centers (ASCs) that report their results in the GI Quality Improvement Consortium (GIQuIC) Registry. Logistic regression was used to identify risk factors for EOCRC.

RESULTS

Increasing age, male sex, White race, family history of CRC, and examinations for bleeding or screening were all associated with higher odds of advanced premalignant lesions (APLs) and CRC. Among patients aged 45 to 49, 32% had any neoplasia, 7.5% had APLs, and 0.58% had CRC. Rates were almost as high in those aged 40 to 44. Family history of CRC portended neoplasia rates 5 years earlier. Rates of APLs were higher in American Indian/Alaskan Natives, but lower among Blacks, Asians, and Hispanics, compared with White counterparts. The prevalence of any neoplasia and APL gradually increased between 2014 and 2019, in all age groups.

CONCLUSIONS

These data provide support for lowering the screening age to 45 for all average-risk individuals. Early messaging to patients and providers in the years leading up to age 45 is warranted, especially in those with a family history of CRC.

Cause, Epidemiology, and Histology of Polyps and Pathways to Colorectal Cancer

Colorectal cancer is the second leading cause of cancer-associated mortality, with a lifetime risk of approximately 4% to 5%. Colorectal cancer develops from the sequential acquisition of defined genetic mutations in the colonic epithelium. Tumorigenesis from normal tissue to cancer occurs largely through 3 pathways: the chromosomal instability pathway, the microsatellite instability pathway, and the sessile serrated pathway. Colorectal cancer incidence and mortality have decreased by approximately 35% since the beginning of screening programs in the 1990s, although other factors such as use of aspirin for coronary disease prevention and decreased smoking rates may also be important. In this review, we discuss the etiology, epidemiology, and histology of colorectal polyps and cancer.

Updates, Controversies, and Emerging Approaches in Colorectal Screening

Colorectal cancer (CRC) is the third most common cancer worldwide and the second leading cause of cancer-related deaths. Despite the threatening statistics, the US burden for CRC has been decreasing, which is likely multifactorial and has partial contribution from widespread timely screening, more advanced CRC treatment, and daily aspirin use in some patients. While overall death rate from CRC decreased by approximately a half between 1975 and 2012, epidemiologic studies demonstrate that CRC incidence is increasing in the younger population. This pattern has prompted the American Cancer Society (ACS) to revise their guidelines. In this review, we plan to discuss the most recent changes in guidelines, data to support them, controversies concerning CRC screening methods, age to start and to stop screening, and post-colonoscopy/polypectomy surveillance guidelines.

Early-Age Onset Colorectal Neoplasia in Average-Risk Individuals Undergoing Screening Colonoscopy: A Systematic Review and Meta-Analysis

BACKGROUND & AIMS

Incidence and mortality associated with early-age onset colorectal cancer (EAO-CRC) is increasing, prompting professional society recommendations to lower the screening age in average-risk individuals. The yield of screening individuals younger than 50 years is not known.

METHODS

A systematic review of 3 databases from inception through July 2020 was performed in all languages that reported colonoscopy findings in average-risk individuals younger than 50 years. The primary outcomes were EAO colorectal neoplasia (CRN) and advanced colorectal neoplasia (aCRN) prevalence. Subgroup analyses were performed based on sex, geographic location, time period, and age, including comparison with those aged 50-59 years. Generalized linear mixed model with random intercept logistic regression and fixed subgroup effects were performed.

RESULTS

Of 10,123 unique articles, 17 studies published between 2002 and 2020, including 51,811 average-risk individuals from 4 continents, were included. The pooled rate of EAO-CRN was 13.7% (95% confidence interval [CI], 0.112%-0.168%) and EAO-aCRN was 2.2% (95% CI, 0.016%-0.031%). Prevalence of CRC was 0.05% (95% CI, 0.00029%-0.0008%). Rates of EAO-CRN were higher in men compared with women (relative risk, 1.71%; 95% CI, 1.49%-1.98%), and highest in the United States (15.6%; 95% CI, 12.2%-19.7%) compared with Europe (14.9%; 95% CI, 6.9%-29.3%), East Asia (13.4%; 95% CI, 10.3%-17.2%), and the Middle East (9.8%; 95% CI, 7.8%-12.2%) (P = .04) The rate of EAO-CRN in age groups 45-49 years and 50-59 years was 17.8% (95% CI, 14.5%-21.6%) and 24.8% (95% CI, 19.5%-30.8%), respectively (P = .04). The rate of EAO-aCRN in age group 45-49 years was 3.6% (95% CI, 1.9%-6.7%) and 4.2% (95% CI, 3.2%-5.7%), respectively (P = .69).

CONCLUSIONS

The rate of aCRN in individuals aged 45-49 years was similar to the rate observed in individual aged 50-59 years, suggesting that expanding screening to this population could yield a similar impact on colorectal cancer risk reduction.

Updates, Controversies, and Emerging Approaches in Colorectal Screening

Colorectal cancer (CRC) is the third most common cancer worldwide and the second leading cause of cancer-related deaths. Despite the threatening statistics, the US burden for CRC has been decreasing, which is likely multifactorial and has partial contribution from widespread timely screening, more advanced CRC treatment, and daily aspirin use in some patients. While overall death rate from CRC decreased by approximately a half between 1975 and 2012, epidemiologic studies demonstrate that CRC incidence is increasing in the younger population. This pattern has prompted the American Cancer Society (ACS) to revise their guidelines. In this review, we plan to discuss the most recent changes in guidelines, data to support them, controversies concerning CRC screening methods, age to start and to stop screening, and post-colonoscopy/polypectomy surveillance guidelines.

Why is colorectal cancer increasing in younger age groups in the United States?

Introduction: While colorectal cancer (CRC) incidence and mortality have decreased for older adults, the rates are increasing in adults younger than 50 years of age in the United States as well as globally. In response to strong epidemiologic evidence as well as sophisticated models, the American Cancer Society (ACS) has recommended screening adults for CRC starting at age 45. Understanding the factors associated with the rise of incidence in adults younger than age 50 may help to identify those adults who may be at greatest risk.Areas covered: In this review, we provide an overview of the recent literature and discuss possible explanations for the increase in CRC in young adults including obesity and other recognized CRC risk factors, delay in diagnosis of symptomatic patients (<50 years of age), and review perspectives on the current and future status of the field.Expert opinion: Currently there are little data regarding risk factors for CRC in average risk young adults who are asymptomatic. With potential endorsement of screening at 45 years of age by US Preventive Services Task Force, more data regarding clinical and molecular risk factors associated with CRC in young adults will be available.

Comprehensive Assessment of Diet Quality and Risk of Precursors of Early-Onset Colorectal Cancer

BACKGROUND

The role of poor diet quality in the rising incidence of colorectal cancer (CRC) diagnosed younger than age 50 years has not been explored. Based on molecular features of early-onset CRC, early-onset adenomas are emerging surrogate endpoints.

METHODS

In a prospective cohort study (Nurses' Health Study II), we evaluated 2 empirical dietary patterns (Western and prudent) and 3 recommendation-based indexes (Dietary Approaches to Stop Hypertension [DASH], Alternative Mediterranean Diet [AMED], and Alternative Healthy Eating Index [AHEI]-2010) with risk of early-onset adenoma overall and by malignant potential (high-risk: ≥1 cm, tubulovillous or villous histology, high-grade dysplasia, or ≥3 adenomas), among 29 474 women with 1 or more lower endoscopy before age 50 years (1991-2011). Multivariable logistic regressions were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

We documented 1157 early-onset adenomas with 375 at high risk. Western diet was positively associated, whereas prudent diet, DASH, AMED, and AHEI-2010 were inversely associated with risk of early-onset adenoma. The associations were largely confined to high-risk adenomas (the highest vs lowest quintile: Western, OR = 1.67, 95% CI = 1.18 to 2.37; prudent, OR = 0.69, 95% CI = 0.48 to 0.98; DASH, OR = 0.65, 95% CI = 0.45 to 0.93; AMED, OR = 0.55, 95% CI = 0.38 to 0.79; AHEI-2010, OR = 0.71, 95% CI = 0.51 to 1.01; all Ptrend ≤ .03), driven by those identified in the distal colon and rectum (all Ptrend ≤ .04, except AMED: Ptrend = .14).

CONCLUSION

Poor diet quality was associated with an increased risk of early-onset distal and rectal adenomas of high malignant potential. These findings provide preliminary but strong support to the role of diet in early-onset CRC.

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

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