Prognostic value of endocrine treatment-related symptoms in patients with breast cancer: a meta-analysis.

PURPOSE: Endocrine therapy is associated with improved disease-free survival (DFS) in hormone receptor-positive breast cancer, but it is also associated with many adverse events. The aim of this study was to clarify the association between endocrine treatment-related symptoms and treatment efficacy in patients receiving adjuvant endocrine therapy.

METHOD: EMBASE, Web of Science, PubMed, and CENTRAL databases were searched for studies that compared treatment efficacy between patients in whom adverse events did and did not occur during hormone therapy. Hazard ratios (HRs) and associated 95 % confidence intervals (CIs) for DFS and overall survival were estimated and pooled using random-effects models.

RESULTS: Of 4665 citations identified, ten studies incorporating 32,192 patients were included in the meta-analysis. The presence of endocrine treatment-related symptoms was associated with improved DFS (HR 0.76; 95 % CI 0.68-0.85). Similar results were observed in patients with vasomotor symptoms (HR 0.76; 95 % CI 0.66-0.87) or musculoskeletal symptoms (HR 0.75; 95 % CI 0.60-0.94), in patients taking an aromatase inhibitor (HR 0.69; 95 % CI 0.57-0.85) or tamoxifen (HR 0.74; 95 % CI 0.60-0.93), and in patients with symptoms at 3-month (HR 0.74; 95 % CI 0.66-0.83), 6-month (HR 0.80; 95 % CI 0.66-0.96), or 12-month follow-up visits (HR 0.75; 95 % CI 0.68-0.83). However, no significant difference in overall survival was observed between patients with or without endocrine treatment-related symptoms (HR 0.82; 95 % CI 0.60-1.11). Sensitivity analysis excluding studies with heterogeneous factors yielded consistent results. No evidence of publication bias was observed.

CONCLUSION: In our meta-analysis, endocrine treatment-related symptoms were shown to correlate with superior DFS and may therefore be useful in predicting treatment efficacy in patients with breast cancer receiving hormone therapy.