# Clinicopathological Features of Endoscopically Resected Early-Onset Colorectal Neoplasia Compared with Later-Onset Cases

## TL;DR

This study compares early-onset and later-onset colorectal lesions and finds that younger adults have distinct features like left-sided location and more advanced pathology.

## Contribution

The study reveals unique clinicopathological features of early-onset colorectal neoplasia identified through endoscopic resection.

## Key findings

- Early-onset lesions were more left-sided and pedunculated compared to later-onset cases.
- Younger patients had larger lesions and higher rates of advanced neoplasia.
- Early-onset disease was associated with more frequent use of advanced endoscopic resection techniques.

## Abstract

Colorectal cancer occurring in adults younger than 50 years has been increasing worldwide, but little is known about the characteristics of the early colorectal lesions that are actually found and removed during routine colonoscopy in this age group. In this study, we examined more than 3000 colorectal lesions removed endoscopically at a large academic hospital and compared their features between younger and older patients. We found that lesions in younger adults were more often located in the left side of the colon, were more likely to have a stalked (pedunculated) shape, and more frequently showed advanced pathological features. These findings suggest that colorectal lesions in younger adults may differ from those in older individuals even before cancer develops. A better understanding of these differences may help improve future research and guide endoscopic practice for younger patients.

Background: The incidence of colorectal cancer diagnosed before age 50 has been increasing worldwide. However, limited data describe the endoscopic and pathological features of colorectal lesions encountered and treated during routine colonoscopy in younger adults. This study aimed to characterize age-related differences in endoscopically resected colorectal neoplasia. Methods: We conducted a retrospective, single-center observational study of consecutively endoscopically resected colorectal neoplasia at a high-volume academic teaching hospital in Japan. Patient-level and lesion-level characteristics were compared between early-onset (<50 years) and later-onset (≥50 years) groups. Lesions were evaluated for location, morphology, size, histology, resection method, and advanced neoplasia status. Results: A total of 1299 patients with 3399 lesions were analyzed, including 498 early-onset patients with 940 lesions. Early-onset neoplasia showed a left-sided predominance, with higher proportions in the distal colon and rectum. Pedunculated morphology was more frequently observed in early-onset lesions. Early-onset disease was also associated with larger lesion size, a higher prevalence of high-grade tubular adenoma, and increased rates of advanced adenoma and advanced neoplasia, resulting in more frequent use of endoscopic mucosal resection or submucosal dissection. Conclusions: Endoscopically resected colorectal lesions in younger adults exhibit distinct anatomical and morphological features compared with later-onset cases, indicating heterogeneity at the premalignant stage.