CTCAE

Common Terminology Criteria for Adverse Events (CTCAE) is a standardized classification and severity grading scale for adverse events in human subjects participating in oncology clinical trials. Developed and maintained by the National Cancer Institute (NCI) of the U.S. National Institutes of Health, CTCAE provides uniform definitions and criteria for reporting a wide range of treatment-related side effects, from mild to life-threatening. The current standard is CTCAE v5.0, released in 2017, with ongoing updates and expansions.

CTCAE organizes adverse events by organ system and assigns a grade from 1 to 5. Grade 1 is mild, grade 2 moderate, grade 3 severe, grade 4 life-threatening or disabling, and grade 5 death. Each event has specific criteria describing the symptoms, functional changes, or laboratory abnormalities that qualify for a particular grade. While CTCAE is primarily clinician-rated, there is also a separate instrument, PRO-CTCAE, for capturing patient-reported symptoms.

CTCAE is widely used to assess the safety profile of cancer therapies in clinical trials and regulatory submissions. It promotes consistent data collection and comparability of toxicity across studies and products, facilitating safety evaluation and decision-making. Training materials accompany the scale to support uniform application. The resources are publicly available through the NCI and related platforms, reflecting CTCAE’s role as a foundational tool in oncology trial safety assessment.