Adenoma and Sessile Serrated Lesion Detection Rates at Screening Colonoscopy for Ages 45-49 Years vs Older Ages Since the Introduction of New Colorectal Cancer Screening Guidelines

National Trends in the Incidence of Sporadic Malignant Colorectal Polyps in Young Patients (20-49 Years): An 18-Year SEER Database Analysis

Background and Objectives: Conflicting guidelines exist for initiating average-risk colorectal cancer screening at the age of 45 years. The United States Preventive Services Task Force (USPSTF) changed its guidelines in 2021 to recommend initiating screening at 45 years due to an increasing incidence of young-onset colorectal cancer. However, the American College of Physicians (ACP) recently recommended not screening average-risk individuals between 45 and 49 years old. We aim to study the national trends in the incidence of sporadic malignant polyps (SMP) in patients from 20 to 49 years old. Materials and Methods: We analyzed the Surveillance, Epidemiology, and End Results database (2000-2017) on patients aged 20-49 years who underwent diagnostic colonoscopy with at least a single malignant sporadic colorectal polyp. Results: Of the 10,742 patients diagnosed with SMP, 42.9% were female. The mean age of incidence was 43.07 years (42.91-43.23, 95% CI). Approximately 50% of malignant polyps were diagnosed between 45 and 49 years of age, followed by 25-30% between 40 and 45. There was an upward trend in malignant polyps, with a decreased incidence of malignant villous adenomas and a rise in malignant adenomas and tubulovillous adenomas. Conclusions: Our findings suggest that almost half of the SMPs under 50 years occurred in individuals under age 45, younger than the current screening threshold recommended by the ACP. There has been an upward trend in malignant polyps in the last two decades. This reflects changes in tumor biology, and necessitates further research and support in the USPSTF guidelines to start screening at the age of 45 years.

Colorectal cancer screening test exposure patterns in US adults 45 to 49 years of age, 2019-2021

Several organizations now recommend that individuals at average risk for colorectal cancer (CRC) begin screening at 45 rather than 50 years of age. We present contemporary estimates of CRC screening in newly eligible adults aged 45 to 49 years between 2019 and 2021. Nationally representative prevalence estimates and population number screened were estimated based on the National Health Interview Survey. A logistic regression model assessed CRC screening prevalence differences by survey year and sociodemographic characteristics. In 2021, 19.7%-that is, fewer than 4 million of the eligible 19 million adults aged 45 to 49 years-were up-to-date on CRC screening. Screening was lowest in those who were uninsured (7.6%), had less than a high school diploma (15.4%), and Asian (13.1%). Additionally, fecal occult blood test and/or fecal immunochemical testing was underused, with only 2.4% (<460 000 people) reporting being up-to-date with screening using this modality in 2021. CRC screening in eligible young adults remains low. Concerted efforts to improve screening are warranted, particularly in underserved populations.

Clinicopathologic and endoscopic features of sessile serrated lesions and conventional adenomas: a large inpatient population-based study in China

Objectives

Sessile serrated lesions (SSLs) are precursors of sporadic colorectal cancer (CRC) and have distinct characteristics compared with conventional adenomas (CAs). Several lifestyle and environmental factors may play critical roles in the development of advanced lesions. Our aim is to describe the features of SSLs and CAs and further explore risk factors for advanced lesions.

Methods

This is an observational study that collected demographic, endoscopic, and histological data from the China-Japan Friendship Hospital among the inpatient population with pathologically reported as SSL or CA between 2015 and 2022. We analyzed the clinicopathology and endoscopic differences between SSL alone, CA alone, and synchronous SSL+CA groups, and identified risk factors using multiple regression analysis.

Results

A total of 9236 polyps from 6598 patients were included in the cohort. Patients with SSL+CA were more likely to be older (p=0.008), while individuals with SSL alone had a higher proportion of early-onset polyps (p<0.001), and SSLs were more common in advanced polyps than CAs (p<0.001). A greater proportion of advanced polyps in the SSL and CA groups were diagnosed as Yamada III, Yamada IV, and laterally spreading tumor (p=0.002, p<0.001, respectively), and multiple SSLs and CAs were more represented in nonadvanced polyps than in advanced polyps. In multiple regression analysis, older patients were more likely to develop advanced SSLs (aOR 1.05, 95% CI 1.02-1.09, p=0.005).

Conclusion

SSLs and CAs have diverse demographic, endoscopic, and histological characteristics, and their advanced lesions share different risk factors, which advances the understanding of the etiology and progression of SSLs.

Screening Implications for Distribution of Colorectal Cancer Subsite by Age and Role of Flexible Sigmoidoscopy

Objectives: The effectiveness of colonoscopy to reduce colorectal cancer (CRC) mortality is extrapolated from cohort studies in the absence of randomized controlled trial (RCT) data, whereas flexible sigmoidoscopy is supported by RCT data and may be easier to implement in practice. We characterized the anatomic distribution of CRC to determine the proportion that is visible with sigmoidoscopy. Methods: Patients with a primary diagnosis of colorectal adenocarcinoma were identified in the Surveillance, Epidemiology, and End Results program (2000-2020). Tumors from the rectum to the descending colon were categorized as visible by sigmoidoscopy, whereas more proximal tumors required colonoscopy. Differential prognosis between tumor locations, stratified by age groups and stage, was assessed using the overall restricted mean survival time (RMST) at 2, 5, and 10 years. Results: Among 309,466 patients, 58% had tumors visible by sigmoidoscopy, including 73% of those under age 50 (OR 2.10, 95% CI 2.03-2.16 age < 45, OR 2.20, 95% CI 2.13-2.27 age 45-49 versus age ≥ 50). Male sex (OR 1.54, 95% CI 1.51-1.56) and Asian or Pacific Islander race (OR 1.60, 95% CI 1.56-1.64) were also positively associated with tumors visualizable by sigmoidoscopy. Across age groups, for local disease, RMST was comparable for tumors visible versus not visible on sigmoidoscopy. For regional and metastatic cancer, patients with tumors visible by sigmoidoscopy had improved RMST versus those with more proximal tumors. Conclusions: 58% of CRC arises in locations visible by flexible sigmoidoscopy. Flexible sigmoidoscopy should be considered as a viable option for CRC screening, particularly in younger patients unwilling or unable to undergo colonoscopy.

Age Matters: Adenoma Detection Rates in Average-risk Screening Patients Aged 45 to 49 Compared With Those Aged 50 to 54

GOALS

This study aims to address gaps in medical knowledge by determining whether adenoma detection rate (ADR) in average-risk screening patients aged 45 to 49 is equivalent to screening patients aged 50 to 54.

BACKGROUND

Current guidelines recommend initiating colon cancer screening at age 45, yet our understanding of the effects of ADR in average-risk individuals among 45- to 49-year-olds is still limited.

STUDY

A retrospective analysis was conducted on records of average-risk screening colonoscopies performed on patients aged 45 to 54 from January 2018 to August 2022. Exclusions were prior diagnoses of colorectal cancer or adenomatous polyps, inflammatory bowel disease, personal or family history of genetic cancer syndromes, incomplete colonoscopy, and inadequate bowel preparation. The primary outcome was ADR in the age 45 to 49 group compared with the age 50 to 54 group.

RESULTS

Of the 3199 average-risk screening colonoscopies performed, 879 and 2116 patients were included in the age 45 to 49 and 50 to 54 groups, respectively. Both groups were predominantly female, White ethnicity, never smokers, and obese. ADR was found to be 27% in the age 45 to 49 group compared with 34% in the age 50 to 54 group (odds ratio 0.70, 90% CI: 0.60-0.83, P-value for equivalence=0.81 w/ margin 0.77 to 1.30).

CONCLUSIONS

The study did not demonstrate equivalent ADR between the 2 age groups, with ADR being substantially lower in the age 45 to 49 group (27% vs. 34%). Despite this, the ADR in the 45 to 49 age range surpasses the established benchmark of 25%, supporting the decision to lower the screening age to 45 years. Ongoing national monitoring is essential to comprehensively evaluate the impact of these updated guidelines.

Adenoma Detection Rate Benchmarks: An Updated Analysis

Early-onset colorectal cancer prompted organizations to reduce the recommended screening initiation age from 50 to 45 years. The American Society for Gastrointestinal Endoscopy Quality Assurance in Endoscopy Committee recommends 3 priority quality indicators for colonoscopy services. The adenoma detection rate is considered the most important measure with the established benchmark based upon studies of patients 50 years or older. The incidence of polyps increases with age, so this change has an as-yet-unknown effect on the new benchmark. Five studies were reviewed. Based upon the results, 45- to 50-year-old patients should be included in facilities' adenoma detection rate calculations using the currently recommended benchmarks of 25% for women and men combined, or 20% for women and 30% for men when the genders are calculated separately. Males consistently had more adenomas than females in each of the 3 studies that separated genders, a detail that might merit gender-based adenoma detection rate determinations in some practices. One study indicated caution is advised; it recommends males and females be calculated separately and different benchmarks be used for each gender. The adenoma detection rate has been shown to increase over time. More studies are needed to guide screening quality metrics.

Risk Factors for Early-onset Sporadic Colorectal Cancer in Male Veterans

Identifying risk factors for early-onset colorectal cancer (EOCRC) could help reverse its rising incidence through risk factor reduction and/or early screening. We sought to identify EOCRC risk factors that could be used for decisions about early screening. Using electronic databases and medical record review, we compared male veterans ages 35 to 49 years diagnosed with sporadic EOCRC (2008-2015) matched 1:4 to clinic and colonoscopy controls without colorectal cancer, excluding those with established inflammatory bowel disease, high-risk polyposis, and nonpolyposis syndromes, prior bowel resection, and high-risk family history. We ascertained sociodemographic and lifestyle factors, family and personal medical history, physical measures, vital signs, medications, and laboratory values 6 to 18 months prior to case diagnosis. In the derivation cohort (75% of the total sample), univariate and multivariate logistic regression models were used to derive a full model and a more parsimonious model. Both models were tested using a validation cohort. Among 600 cases of sporadic EOCRC [mean (SD) age 45.2 (3.5) years; 66% White], 1,200 primary care clinic controls [43.4 (4.2) years; 68% White], and 1,200 colonoscopy controls [44.7 (3.8) years; 63% White], independent risk factors included age, cohabitation and employment status, body mass index (BMI), comorbidity, colorectal cancer, or other visceral cancer in a first- or second-degree relative (FDR or SDR), alcohol use, exercise, hyperlipidemia, use of statins, NSAIDs, and multivitamins. Validation c-statistics were 0.75-0.76 for the full model and 0.74-0.75 for the parsimonious model, respectively. These independent risk factors for EOCRC may identify veterans for whom colorectal cancer screening prior to age 45 or 50 years should be considered.

PREVENTION RELEVANCE

Screening 45- to 49-year-olds for colorectal cancer is relatively new with uncertain uptake thus far. Furthermore, half of EOCRC occurs in persons < 45 years old. Using risk factors may help 45- to 49-year-olds accept screening and may identify younger persons for whom earlier screening should be considered. See related Spotlight, p. 479.

Screening Implications for Distribution of Colorectal Cancer Subsite by Age

Objectives

The effectiveness of colonoscopy to reduce colorectal cancer (CRC) mortality is extrapolated from cohort studies in the absence of randomized controlled trial (RCT) data, whereas flexible sigmoidoscopy is supported by RCT data and may be easier to implement in practice. We characterized the anatomic distribution of CRC to determine the proportion that is visible with sigmoidoscopy.

Methods

Patients with a primary diagnosis of colorectal adenocarcinoma were identified in the Surveillance, Epidemiology, and End Results program (2000-2020). Tumors from the rectum to descending colon were categorized as visible by sigmoidoscopy, whereas more proximal tumors as requiring colonoscopy. Differential prognosis between tumor locations, stratified by age groups and stage, were assessed using overall restricted mean survival time (RMST) at 2, 5, and 10 years.

Results

Among 309,466 patients, 58% had tumors visible by sigmoidoscopy, including 73% of those under age 50 (OR 2.10, 95%CI 2.03-2.16 age <45, OR 2.20, 95%CI 2.13-2.27 age 45-49 versus age > 50). Male sex (OR 1.54, 95%CI 1.51-1.56) and Asian or Pacific Islander race (OR 1.60, 95%CI 1.56-1.64) were also positively associated with tumors visualizable by sigmoidoscopy. Across age groups, for local disease, RMST was comparable for tumors visible versus not visible on sigmoidoscopy. For regional and metastatic cancer, patients with tumors visible by sigmoidoscopy had improved RMST versus those with more proximal tumors.

Conclusions

Most CRC arise in locations visible by flexible sigmoidoscopy. Flexible sigmoidoscopy should be considered as a viable option for CRC screening, particularly in younger patients unwilling or unable to undergo colonoscopy.

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.

"Endoscopic" adenoma detection rate as a quality indicator of colonoscopy: First report from the J-SCOUT study

OBJECTIVES

To examine whether reasonable detection rate of endoscopically diagnosed lesions as adenoma ("endoscopic" adenoma detection rate [ADR]) could be calculated with a database generated from colonoscopy reports and whether it could be used as a surrogate colonoscopy quality indicator of "pathological" ADR.

METHODS

A lesion-by-lesion database of colonoscopies performed between 2010 and 2020 at eight Japanese endoscopy centers and corresponding pathology database were integrated. Differences in numbers of detected polyps, "endoscopic" and "pathological" adenomas, and what these differences could be attributed to were examined. Polyp detection rate (PDR), "endoscopic" and "pathological" ADRs, and correlation coefficients between "pathological" ADR and PDR or "endoscopic" ADR by each endoscopist were calculated.

RESULTS

Overall, 129,065 colonoscopy reports were analyzed. Among a total of 146,854 polyps, more "endoscopic" adenomas (n = 117,359) were observed than "pathological" adenomas (n = 70,076), primarily because adenomas were not resected on site, rather than because of a misdiagnosis. In all patients analyzed, PDR, "endoscopic" and "pathological" ADRs were 56.4% (95% confidence interval [CI] 56.2-56.7), 48.0% (95% CI 47.7-48.3), and 32.7% (95% CI 32.5-33.0), respectively. "Endoscopic" and "pathological" ADRs from each endoscopist showed a high correlation in hospitals where adenomas were usually resected at the time of examination.

CONCLUSIONS

By appropriately describing endoscopically diagnosed lesions as "adenomas" in endoscopy reports, "endoscopic" ADR might be used as a surrogate colonoscopy quality indicator of "pathological" ADR (UMIN000040690).