Assessment of quality of life (QOL) in MA.17, a randomized placebo-controlled trial of letrozole in postmenopausal women following five years of tamoxifen

Abstract

517 Background: The NCIC CTG MA.17 demonstrated substantial improvement in DFS by administering letrozole after 5 years of adjuvant tamoxifen to postmenopausal women with early stage breast cancer. An increase in low-grade hot flashes, arthritis, arthralgias and myalgias were identified in patients treated with letrozole. The objective of this sub-study was to evaluate QOL. Methods: Patients completed the Medical Outcomes Study 36 Item Short Form General Health Survey (SF36) and the Menopause Specific QOL (MENQOL) questionnaire at baseline, six months and annually. Mean change scores from baseline were compared between letrozole and placebo for summary measures and domains. The proportion of patients who demonstrated a minimally important worsening in QOL (defined as a difference from baseline of 5 points for SF36 and 0.5 for MENQOL) was also compared. An alpha of 0.01 was used in view of multiple comparisons. The analysis was limited to the first 3 years. Results: Of 5,187 women enrolled, 3,582 participated in the QOL sub-study. Baseline scores on the SF36 physical and mental health summary measures were similar to healthy populations and decreased over time in both groups. There were no significant differences between groups in mean change scores at 6, 12, 24 and 36 months. Small [<0.1 standard deviation (SD)] but statistically significant differences were seen for SF36 physical functioning (6, 12 months), bodily pain (6 months), vitality (6, 12 months) and MENQOL physical domains (12 months). Moderate (0.2–0.3 SD) differences were observed for the MENQOL vasomotor (6, 12, 24 months), and sexual domains (12, 24 months). Absolute increases in % of patients reporting worsening in their QOL at any time on letrozole compared to placebo for the different domains were: SF36 physical functioning (6%, p < .001); bodily pain (5%, p=.001); vitality (5%, p=.005); MENQOL vasomotor (8%, p< .001); physical (5%, p=.004); and sexual (4%, p=.02). Conclusions: Letrozole did not have a substantial adverse impact on QOL. Small effects were seen in some domains consistent with a minority of patients experiencing adverse effects. Author Disclosure Employment or Leadership Consultant or Advisory Stock Ownership Honoraria Research Funding Expert Testimony Other Remuneration Novartis