Relationship between specific adverse events and efficacy of exemestane therapy in early postmenopausal breast cancer patients
Fontein, D B Y × Houtsma, D Hille, E T M Seynaeve, C Putter, H Meershoek-Klein Kranenbarg, E Guchelaar, H J Gelderblom, H Dirix, L Y Paridaens, Robert Bartlett, J M S Nortier, J W R van de Velde, C J H on behalf of the Dutch TEAM Steering Committee #
Kluwer Academic Publishers
Annals of Oncology vol:23 issue:12 pages:3091-3097
BackgroundMany adverse events (AEs) associated with aromatase inhibitors (AIs) involve symptoms related to the depletion of circulating estrogens, and may be related to efficacy. We assessed the relationship between specific AEs [hot flashes (HF) and musculoskeletal AEs (MSAE)] and survival outcomes in Dutch and Belgian patients treated with exemestane (EXE) in the Tamoxifen Exemestane Adjuvant Multinational (TEAM) trial. Additionally, the relationship between hormone receptor expression and AEs was assessed.MethodsEfficacy end points were relapse-free survival (RFS), overall survival (OS) and breast cancer-specific mortality (BCSM), starting at 6 months after starting EXE treatment. AEs reported in the first 6 months of treatment were included. Specific AEs comprised HF and/or MSAE. Landmark analyses and Cox proportional hazards models assessed survival differences up to 5 years.ResultsA total of 1485 EXE patients were included. Patients with HF had a better RFS than patients without HF [multivariate hazard ratio (HR) 0.393, 95% confidence interval (CI) 0.19-0.813; P = 0.012]. The occurrence of MSAE versus no MSAE did not relate to better RFS (multivariate HR 0.677, 95% CI 0.392-1.169; P = 0.162). Trends were maintained for OS and BCSM. Quantitative hormone receptor expression was not associated with specific AEs.ConclusionsSome AEs associated with estrogen depletion are related to better outcomes and may be valuable biomarkers in AI treatment.