There is no standardized and universally accepted pain classification system for the
assessment and management of cancer pain in both clinical practice and research studies. The
Edmonton Classification System for Cancer Pain (ECS–CP) is an assessment tool that has
demonstrated value in assessing pain characteristics and response. The purpose of our study
was to determine the relationship between negative ECS–CP features and some pain-related
variables like pain intensity and opioid use. We also explored whether the number of negative
ECS–CP features was associated with higher pain intensity.