Lead Sponsor

Run-hua Li

Age

18 - 50 years

Sex

ALL

Healthy Volunteers

No

•Age ≤ 50 years
•Pathologically confirmed colorectal neoplasia diagnosed at Shenzhen Hospital, Southern Medical University between 2016-01-01 and 2025-09-30, defined as colorectal cancer (any T stage) or high-grade intraepithelial neoplasia (HGIN).
•Available source documentation: complete or retrievable clinical record, endoscopy report, and pathology report sufficient to determine diagnosis and stage.
•De-identifiable data available for extraction (records can be coded and exported without direct identifiers).
•No requirement for additional patient contact (retrospective use of existing records with IRB-approved consent waiver or documented consent per ethics approval).

•Secondary/metastatic colorectal tumor (colorectal involvement proven to be metastasis from another primary site).
•Prior history of other active malignancy within the last 5 years that could confound staging or outcomes, unless disease is in long-term remission and clearly documented.
•Insufficient documentation to determine pathological diagnosis or T stage (key pathology report missing or illegible).
•Critical data missing for primary outcome (e.g., pathology date or staging information) that cannot be resolved after source review.
•Duplicate records or irreconcilable data (same patient with conflicting identifiers/records that cannot be reconciled).
•Patients who received initial diagnostic or therapeutic care outside the study site with no accessible pathology or endoscopy reports at Shenzhen Hospital.