A real-life study on the implementation and effectiveness of exemestane plus everolimus per hospital type in patients with advanced breast cancer. A study of the Southeast Netherlands Advanced Breast Cancer registry.

Purpose: We aimed to assess the implementation and effectiveness of exemestane plus everolimus treatment per hospital type in real-life, shortly after approval of everolimus.

Methods: Advanced breast cancer patients treated with exemestane plus everolimus in 2012-2014 were included from the SONABRE registry. Progression-free survival (PFS) and a 12-week conditional PFS (post-hoc) were estimated by Kaplan-Meier method. The multivariable Cox proportional hazards model was performed by type of hospital and adjusted for patient, tumour and treatment characteristics.

Results: We included 122 patients, comprising 48 patients treated in academic (N = 1), 56 in teaching (N = 4), and 18 in non-teaching (N = 2) hospitals. The median PFS was 6.3 months (95% Confidence Interval (CI) 4.0-8.6) overall, and 8.5 months (95% CI 7.7-9.3), 4.2 months (95% CI 2.0-6.3), and 5.5 months (95% CI 4.2-6.7) for the patients treated in academic, teaching and non-teaching hospitals, respectively. The adjusted Hazard Ratio (HR) for PFS-events was 1.5 (95% CI 1.0-2.2) and 1.0 (95% CI 0.5-1.9) respectively for patients treated at teaching and non-teaching hospitals versus the academic hospital. The adjusted HR for 12-week conditional PFS-events was not different between hospital types. In the first 12-week treatment period, treatment was discontinued due to early progression in one out of 48 patients in the academic versus nine out of 74 patients in the non-academic hospitals, confirmed by imaging in one and two patients, respectively.

Conclusions: In our study, the median PFS was borderline significantly different between hospital types, possibly the result of a different assessment approach in the first 12-week treatment period.