biostudies-literatureMenz BDTour de CureHospital Research FoundationNational Health and Medical Research Council2135-2145https://www.ebi.ac.uk/biostudies/studies/S-EPMC12439079biostudies-literatureUnknown157(10)Researchers at the EORTC recently recommended clinical thresholds for the QLQ-C30 to facilitate actionable insights in clinical practice. We evaluate the distribution of these thresholds and associations with outcomes in breast cancer. Data were pooled from two early-stage and six advanced-stage breast cancer trials. EORTC thresholds were applied to available QLQ-C30 data to identify clinically important PRO domains. Associations between the number of clinically important PRO domains at baseline with overall survival (OS), invasive-disease-free survival (IDFS), progression-free survival (PFS), grade ≥3 adverse events (AEs), and serious AEs were evaluated using Cox-regression. Data from 8544 breast cancer patients, of whom 2428 (41%) of the 5893 early-stage and 1486 (56%) of the 2651 advancInternational journal of cancerPatient-reported outcome thresholds and their associations with survival, adverse events, and quality of life in a pooled analysis of breast cancer trials.PMC124390792023‐S‐DTFA‐005APP20309132023-S-DTFA-005APP2008119RSP-117-FY2023RSP‐117‐FY2023Lyman GHMenz BDHopkins AMChan RJShahnam AKuderer NMSorich MJRowland AHaseloff MRammant ERamsey IModi NDVitry AMcKinnon RAAbuhelwa AYKichenadasse GSwain SMfalsePatient-reported outcome thresholds and their associations with survival, adverse events, and quality of life in a pooled analysis of breast cancer trials.Researchers at the EORTC recently recommended clinical thresholds for the QLQ-C30 to facilitate actionable insights in clinical practice. We evaluate the distribution of these thresholds and associations with outcomes in breast cancer. Data were pooled from two early-stage and six advanced-stage breast cancer trials. EORTC thresholds were applied to available QLQ-C30 data to identify clinically important PRO domains. Associations between the number of clinically important PRO domains at baseline with overall survival (OS), invasive-disease-free survival (IDFS), progression-free survival (PFS), grade ≥3 adverse events (AEs), and serious AEs were evaluated using Cox-regression. Data from 8544 breast cancer patients, of whom 2428 (41%) of the 5893 early-stage and 1486 (56%) of the 2651 advanc2025-01-01T00:00:00Z2025 Nov2026-06-03T03:02:14.135Z2026-04-23T03:13:52.726ZS-EPMC124390794054260910.1002/ijc.70020