What issues should be noted regarding sample collection timing in clinical trials of in‑vitro diagnostic reagents for auxiliary diagnosis and screening of colorectal cancer?
In‑vitro diagnostic reagents for colorectal cancer auxiliary diagnosis and screening usually take colonoscopy results as the clinical reference standard for comparative studies.
Special attention shall be paid to the time interval between sample collection and colonoscopy examination during clinical trials. Invasive operations in colonoscopy may significantly affect the level of tumor markers in test samples such as stool and plasma.
Therefore, samples for in‑vitro diagnostic testing should be collected prior to colonoscopy. To ensure comparability between test results and colonoscopy findings, the time interval between sample collection and colonoscopy is recommended not to exceed 12 weeks.
Strict control over sample‑collecting timing helps avoid unacceptable bias in clinical trials and guarantees the scientific validity of clinical data for IVD reagents.
