A Review of Meaningful Change Thresholds for EORTC QLQ-C30 and FACT-G Within Oncology

This literature review provides an overview of meaningful change thresholds for the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (QLQ-C30) and the Functional Assessment of Cancer Therapy - General (FACT-G) used across hematological cancers and solid tumors (melanoma, lung, bladder, and prostate).

Embase, MEDLINE, and PubMed were searched to identify relevant oncology publications from 2016 to 2021. Label claims from the US Food and Drug Administration and the European Medicines Agency for 7 recently approved drugs (pembrolizumab, atezolizumab, glasdegib, gilteritinib, tisagenlecleucel, axicabtagene ciloleucel, and daratumumab plus hyaluronidase-fihj) were reviewed.

Publications providing guidance on meaningful change thresholds for the QLQ-C30 displayed a growing trend away from broad "legacy" thresholds of 10 points for all QLQ-C30 scales), toward deriving "contemporary" thresholds (eg, subscale specific, population specific). Contemporary publications generally provide guidance on selecting thresholds for specific scales that account for improved or worsening thresholds (eg, QLQ-C30 subscales). This trend was not clear for FACT-G, with less new guidance available. Most clinical trials used in regulatory label submissions have used thresholds of 10 points for the QLQ-C30 subscales and 3 to 7 points for the FACT-G total score. Despite the availability of more recent guidelines, contemporary meaningful change thresholds seem slow to emerge in the published literature and regulatory labels.

Trialists should consider using contemporary thresholds, rather than legacy thresholds, for QLQ-C30 endpoints. Thresholds derived for a similar patient-population should be used where available. Further work is required to provide these across a broader range of cancer sites.