Young patients with sporadic colorectal adenomas: current endoscopic surveillance practices and outcomes

A Case of Sporadic Multiple Colonic Polyps in a Young Woman

Sporadic colorectal cancer arises from an adenoma. As mutations in the adenomatous polyposis coli (APC) tumor suppressor gene have been frequently detected in colorectal adenomas, the APC gene is considered a gatekeeper in colorectal carcinogenesis. Here, we report a case of sporadic multiple colonic adenomas that were accompanied by an APC-truncating mutation. A 25-year-old Korean woman presented with dozens of incidentally found colonic polyps. There was no family history of colorectal polyposis or colon cancer in her first or second-degree relatives. All the polyps were removed endoscopically at once, and their pathological examination revealed tubular adenoma. Mutational analysis showed a 2-bp deletion mutation at codon 443, which generates a premature stop codon at codon 461 of the APC gene, and Western blot analysis demonstrated both wild-type and truncated APC proteins in adenoma tissue. This study suggests that a single truncating mutation of the APC gene may initiate adenoma formation.

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.

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

BACKGROUND & AIMS

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Comparison of Risk of Metachronous Advanced Colorectal Neoplasia in Patients with Sporadic Adenomas Aged < 50 Versus ≥ 50 years: A Systematic Review and Meta-Analysis

No specific recommendations are available for the surveillance of young patients aged <50 years undergoing polypectomy. We aimed to compare the risk of metachronous advanced colorectal neoplasia (ACRN) between patients aged ≥50 years and those aged <50 years who underwent polypectomy. Studies published between January 1980 and June 2020 that examined the risk of metachronous ACRN were searched. We performed a meta-analysis for the metachronous ACRN risk in patients with sporadic colorectal adenomas according to the age groups (≥50 vs. <50 years). Eight individual studies were included in the meta-analysis. The risk of metachronous ACRN was higher in patients aged ≥50 years than in those aged <50 years without significant heterogeneity (odds ratio (OR) (95% CI): 1.62 (1.34–1.96), I² = 14%). The impact of the age group on the risk of metachronous ACRN was identified in both the low-risk (LRA) and high-risk (HRA) adenoma groups (≥50 vs. <50 years: LRA, OR 1.88 (95% CI 1.30–2.70); HRA, OR 1.50 [95% CI 1.13–2.00]). In conclusion, patients aged <50 years had a lower risk of metachronous ACRN than older patients. Young patients with sporadic adenomas do not require more intensive surveillance; rather, the surveillance interval may be extended in these patients.

Young adults and metachronous neoplasia: risks for future advanced adenomas and large serrated polyps compared with older adults

BACKGROUND AND AIMS

Recent increases in colorectal cancer (CRC) incidence in adults younger than 50 years of age have led to more colonoscopies in this age group. As a result, there may be an increasing number of adults <50 years old with polyps detected. There is concern that younger adults may require closer follow-up. Our goal was to use data from the New Hampshire Colonoscopy Registry (NHCR) to examine the risk for metachronous advanced adenomas (AAs) and large (>1 cm) serrated polyps in younger versus older adults who return for a follow-up colonoscopy.

METHODS

Our cohort consisted of NHCR participants with at least 1 polyp on index examination and a follow-up colonoscopy at least 1 year after the index examination. Outcomes were the risks for metachronous AAs (adenomas ≥1 cm, with villous elements or high-grade dysplasia, or CRC) and large (≥1 cm) serrated polyps. We present absolute risk and adjusted risks from a logistic regression model stratified by age at index colonoscopy (<40, 40-49, 50-59, and 60+ [reference]). Covariates included index findings, endoscopist adenoma detection rates, sex, smoking, body mass index, follow-up time (months), bowel preparation quality, and family history of CRC.

RESULTS

In our sample of 12,380 adults, absolute risk for metachronous AA was lower for younger patients than for patients aged ≥60. After adjusting for covariates, when comparing with the 60+ group (reference), the lowest risk was observed in those younger than 40 years (odds ratio, .19; 95% confidence interval, .05-.80). Of note, similar risks were observed in the 40 to 49 age group (odds ratio, .61; 95% confidence interval, .41-.92) and 50 to 59 age group (odds ratio, .71; 95% confidence interval, .58-.86). The risk for large metachronous serrated polyps was not associated with age.

CONCLUSIONS

Younger adults aged <40 with index adenomas had a lower risk for metachronous AAs than those aged ≥60. The 40- to 49-year age group was found to have metachronous risk similar to the 50- to 59-year age group, with both less than the ≥60 age group. These data suggest that current surveillance interval guidelines for patients aged ≥50 years may appropriately be used with younger adults.

A Review of the Management of Sporadic Colorectal Adenomas in Young People: Is Surveillance Wasted on the Young?

The national incidence of colorectal cancer is increasing in people younger than 50 years old. Although diagnostic colonoscopy is detecting more sporadic adenomas in young adults, there are no guidelines for post-polypectomy surveillance. The aim of this review was to survey the medical literature on the prevalence of sporadic adenomas in young adults, subsequent risk of metachronous neoplasia, and lastly to provide several concluding recommendations for clinical practice. We found that the prevalence of sporadic adenomas in young adults is greater than initially estimated and dependent upon factors such as colonoscopy indication and age. The incidence of metachronous colorectal neoplasia following polypectomy is unclear but does not appear to be greater than that of older adults. Risk factors for metachronous neoplasia include findings on index colonoscopy, male gender, smoking status, and certain medical comorbidities. Upon finding a colorectal adenoma in a young person, we suggest that a detailed family history be obtained to confirm that it is truly sporadic. Testing adenomas for evidence of Lynch syndrome is low yield. Strategies to inform surveillance intervals may include an assessment of risk factors for metachronous neoplasia, although surveillance intervals shorter than those recommended in current guidelines are not warranted. Future research should focus on obtaining long-term, prospective data on the incidence of metachronous neoplasia in diverse patient populations.