Prognostic value of quality of life scores for time to progression (TTP) and overall survival time (OS) in advanced breast cancer.

The purpose of the study was to investigate whether baseline quality of life (QoL) and changes in QoL scores from baseline are prognostic for time to progression (TTP) and/or overall survival (OS) in patients with advanced breast cancer receiving docetaxel (T) or sequential methotrexate and 5-fluorouracil (MF). QoL was assessed at baseline and before each treatment using the European Organization for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire (QLQ-C30). Survival curves and probabilities were estimated using the Kaplan-Meier technique. The Cox proportional hazards regression model was used for both the univariate and multivariate analyses to explore relationships between baseline QoL variables and TTP, as well as OS. In the univariate analysis, more severe pain and fatigue at baseline were predictive for a shorter OS; global QoL, physical functioning and appetite loss had a borderline significance (P=0.0130 for global QoL; P=0.0256 for physical functioning: P=0.0149 for appetite loss). World Health Organization (WHO) performance status was significantly predictive for OS. In the multivariate analysis, more severe pain at baseline was predictive for a shorter OS. In contrast, baseline QoL had no prognostic value for the duration of TTP. QoL change scores from baseline QoL predicted neither OS nor TTP. Our findings suggest that while QoL measurements are important in evaluating patients' QoL, they have no great importance in predicting primary clinical endpoints such as TTP or OS in advanced breast cancer patients.

Timing of quality of life (QoL) assessments as a source of error in oncological trials.

AIM OF THE STUDY: To produce an empirical estimate of the nature and magnitude of the error produced by incorrect timing quality of life (QoL) measurements in patients receiving chemotherapy. DESIGN: In a multicentre trial, 283 patients were randomized to receive either docetaxel (T) or sequential methotrexate and 5-fluorouracil (MF). The QoL was assessed at baseline and before each treatment using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ-C30). The study design was retrospective. Data were analysed using t-tests. RESULTS: Erroneous timing affected the QoL findings in both treatment arms. At baseline, there were statistically significant differences in the MF group on the nausea/vomiting scale, with ill-timed assessment showing more symptoms, and in the T group on the physical functioning scale with ill-timed assessments indicating better QoL. The mean scores of correct vs. incorrect timings over the first 14 cycles showed statistically significant differences on several scales. In the MF group, ill-timed assessments indicated significantly worse physical functioning and global QoL, and significantly more of the following symptoms: fatigue, nausea/vomiting, insomnia, appetite loss, and constipation. In the T group, ill-timed assessment showed better physical functioning, less dyspnoea and more insomnia than correctly timed assessments. The reasons for erroneous timing were not always detectable retrospectively. However, in some cases the MF group, being in standard treatment, seemed to have followed a clinical routine not involving the active participation of the study nurse responsible, whereas patients in the experimental T group were more consistently taken care of by the study nurses. CONCLUSIONS: Incorrect timing of QoL assessments in oncological trials jeopardises both the reliability of the QoL findings within treatment and the validity of QoL outcome comparisons between treatments. This issue should be emphasized in the planning of both the study design and clinical routines.