Quality of Life in an e-Cohort of Women Treated by Endocrine Therapy for Early Breast Cancer

The objective of our study was to analyze quality of life (QOL) in an e-cohort of patients treated for breast cancer (BC) by endocrine therapy (ET), by means of validated quality of life questionnaires. A retrospective, observational, e-cohort study was conducted (Seintinelles platform). Female patients treated for nonmetastatic and nonrecurrent BC, treated in France after 2005, filled in online questionnaires concerning: QOL (QLQ-C30 and QLQ-BR23), tolerability of treatment and demographic characteristics. A multivariate analysis including variables significant on univariate analysis (P < .05) to select QOL predictors was performed. We included 1,198 patients, 1140 of whom declared that they were taking ET (37.7% tamoxifen, 17.1% aromatase inhibitor (AI), 5.6% LHRH-agonist and 39.6% sequential tamoxifen and AI). Different tolerability profiles were observed when comparing the tamoxifen and AI groups. Treatment adherence was similar in the 2 groups. QOL varied slightly according to the type of ET. On multivariate analysis, ET had no impact on QOL. However, individual patient characteristics (socioeconomic, education and age) were significantly associated with QOL Using a real-life study questionnaire on a large e-cohort, individual patient characteristics were strongly associated with deterioration of QOL. The use of e-cohorts must be encouraged to modulate the conclusions of randomized trials. Quality of life (QOL) was assessed in an e-cohort of patients treated for breast cancer by endocrine therapy, by means of validated quality of life questionnaires. Endocrine therapy does not alter QOL. Individual patient characteristics (socioeconomic, education and age) were significantly associated with QOL. The use of e-cohorts must be encouraged to study patient reported outcomes without medical inference.