Timing of baseline quality of life assessment in an international adjuvant breast cancer trial: its effect on patient self-estimation. The International Breast Cancer Study Group.

BACKGROUND: Variability in timing of baseline quality of life (QL) assessments in two ongoing International Breast Cancer Study Group (IBCSG) randomized clinical trials occurred as a result of allowing some flexibility in the timing. This retrospective report describes the QL timing in relation to surgery and start of adjuvant therapy and its effect on QL self-estimation. PATIENTS AND METHODS: Self-administered measures of baseline QL were obtained on day 1 of adjuvant therapy or as close to that date as possible from 1389 pre- and post-menopausal women with operable breast cancer.
RESULTS: Fifty-four percent of QL assessments were done on day 1 of adjuvant therapy, 18% before day 1 and 28% after. An ANOVA, controlling for surgery, institution and language, showed that: for patients receiving endocrine therapy alone, QL improved as time from surgery increased, but start of adjuvant treatment had no effect, while for chemotherapy patients, appetite, physical well-being and, in pre-menopausal patients, coping were worse 1 to 5 days after the start of treatment. Chemotherapy had little effect on mood and emotional well-being.
CONCLUSIONS: Timing of QL assessment in relation to diagnosis affects global adjustment measures; timing in relation to chemotherapy affects measures sensitive to toxicity. Timing is an important consideration in study conduct and data analysis.