1. Patterns of care and comparative effectiveness of endocrine therapy for premenopausal women with early breast cancer A multi-institution cohort study February 2015Arlindo R. Ferreira

2. Background BC is the most common cause of cancer-related deaths in females in the EU Most tumors are hormone receptor-positive −Eligible for hormone related therapies

3. Background ET has evolved considerably over the last 10 years For premenopausal women, adjuvant ET includes: −Tamoxifen for 10 years 1 −Ovarian suppression + Tamoxifen 2 −Ovarian suppression + Exemestane 2 Knowing real world use allows to: −Design practice guidelines −Inform future interventions −Promote comparative effectiveness studies Remaining premenopausal after CT Multiple positive nodes < 35 with appropriate disease-associated risks 1 - Burstein, H. J. (2014) Adjuvant Endocrine Therapy for Women With Hormone Receptor-Positive Breast Cancer: American Society of Clinical Oncology Clinical Practice Guideline Focused Update. Journal of Clinical Oncology, 32(21), 2255–2269. 2- Coates, A. S. (2015) Tailoring therapies—improving the management of early breast cancer: St Gallen International Expert Consensus on the Primary Therapy of Early Breast Cancer 2015. Annals of Oncology, 26(8), 1533–1546.

4. Purpose In this study we aim to: −Characterize how recent changes in standard practice impacted daily routine clinical use of endocrine therapy −Interrogate how intensified endocrine therapy regimens in premenopausal women compare to less intensive regimens −Describe the use of extended ET regimens

5. Study objectives Specific objective 1 To detail patterns of use of ET in the adjuvant treatment of premenopausal women Specific objective 2 To quantify the relative effectiveness of adjuvant TAM alone (for 5 and/or 10 years) or in combination with OS To quantify the relative effectiveness of adjuvant TAM vs. AI when used in combination with OS To quantify the relative effectiveness of a) and b) in the subgroup of premenopausal patients <35 years or treated with adjuvant CT.

6. Study objectives Specific objective 3 To identify the clinical and pathological predictors of early ( 5 years) according to histological subtype and adjuvant endocrine therapy; To describe baseline clinicopathological, demographic and institutional characteristics associated with patterns of prescription of ET.

7. Study design and outcomes Retrospective cohort study Outcomes: −Death from any cause −Disease recurrence (if available)

8. Patients eligibility Premenopausal women Breast cancer Diagnosis from 01/01/2006 to 31/12/2010 (5 years FU) Hormone receptor positive HER2-negative Stage I-III Treated at a GESCAM institution

9. Patterns of care and comparative effectiveness of endocrine therapy for premenopausal women with early breast cancer A multi-institution cohort study February 2015Arlindo R. Ferreira