AbstractsMedical & Health Science

Background: The EORTC QLQ-C30 and the FACT are two commonly used Health-Related Quality of Life (HRQL) instruments in cancer clinical trials, but there is limited data comparing them. The NCIC CTG PR.3 clinical trial compared Androgen Deprivation Therapy (ADT) alone with ADT plus radiation therapy (ADT + RT) in prostate cancer patients. In a PR.3 sub-study, we conducted a comparison of the EORTC QLQ-C30+3 and prostate module (PR17) to FACT-P by employing a cluster randomization of 29 participating North American centers to HRQL instrument used on the PR.3 clinical trial. Purpose: To compare the responsiveness of two HRQL instruments to short-term radiation effects and long-term hormone effects in men treated for locally advanced prostate cancer on a clinical trial. Methods: 311 patients randomized to the PR.3 sub-study were included for analysis. HRQL was assessed at baseline, 6 monthly (for 2 years), then annually; compliance exceeded 85% to three years. The ability of each HRQL instrument to detect RT toxicity was determined by comparing mean change scores (ADT vs. ADT + RT arms) at 6 months by HRQL instrument (Wilcoxon rank-sum). The ability of each instrument to detect proportions changed (at 6 or 36 months) was determined by calculating proportions (clinically meaningful change defined as 10% change from baseline) then comparing between instrument groups (chi-square). Finally, we compared instruments on time to clinically meaningful worsening of HRQL using Kaplan-Meier survival curves/Cox regression. Results: The FACT-P detected significant between-treatment arm differences in urinary symptom change scores at 6 months. The EORTC QLQ-C30+3/PR17 detected significant between-treatment arm differences in diarrhea and bowel/rectum symptom changes at 6 months. For functional domains and fatigue, no significant between-instrument differences were observed in proportions of patients improved/stable and worsened at and up to 36 months. However, the FACT-P reported a faster rate of clinically meaningful HRQL decline for physical and role/functional domains. Conclusions: When randomly assigned to patients participating in a clinical trial, the FACT-P and EORTC QLQ-C30+3/PR17 instruments differed in responsiveness to changes in urinary and bowel symptoms attributable to radiotherapy. The FACT-P was more responsive to change in physical and role function over time.