Artigo

Extended Endocrine Therapy Following 5 Years of AdjuvantLuteinizing Hormone-Releasing Hormone Agonist inPremenopausal Patients With Node-Positive, HormoneReceptor–Positive Breast Cancer: A Cohort Study

Autor(es): Carmine Valenza, MD, MPH 1,2,3,4,5 Lorenzo Guidi, MD 2,3 ; Pier Paolo Maria Berton Giachetti, MD 2,3 ; Monica Milano, MD, PhD 7 ; Dario Trapani, MD 2,3 ; Elisa Giordano, MD 2,3 ; ; Laura Boldrini, MD 2,3 ; Grazia Castellano, MD 2,3 Bianca Malagutti, MD 2,3 ; Gabriele Antonarelli, MD, PhD 2,3 Gregory J. Kirkner, MPH 4,5 ; Fabio Conforti, MD, PhD 8 ; Jalissa Katrini, MD 2,3 ; ; Eleonora Pagan, PhD 9 ; Vincenzo Bagnardi, PhD 9 ; Claudia Sangalli, BSc 10 ; Kate E. Dibble, PhD 4,5,11 Elisabetta Munzone, MD 7 ; Giuseppe Curigliano, MD, PhD 2,3 ; Marco Colleoni, MD 7 ; and Ann H. Partridge, MD, MPH 4,5,11 ;

Abstract

PURPOSE To evaluate the clinical benefit of extended endocrine therapy (eET) after 5 years of adjuvant treatment with luteinizing hormone-releasing hormone agonists (LHRHa) in premenopausal women with node-positive, hormone receptor–positive early breast cancer (eBC).

METHODS We conducted a cohort study analysis on two prospectively collected data sets (the Young Women’s Breast Cancer Study and IEO Breast Cancer Cohort). El igible patients were diagnosed with eBC at age ≤40 years (between 2005 and 2016), had node-positive, hormone receptor–positive disease, and remained premenopausal after 5 years of adjuvant LHRHa with no evidence of recurrence. The primary end point was invasive breast cancer–free survival (IBCFS), cal culated from the sixth year after the initiation of adjuvant endocrine therapy (ET; study baseline), and adjusted through the propensity score (PS) weighting analysis.

RESULTS A total of 501 patients were included in the analysis: 287 received eET for a median duration of 3.7 years (IQR, 2.3-5.0), including 48% tamoxifen monotherapy and 52% LHRHa plus tamoxifen or aromatase inhibitor. After a median follow-up of 7.3 years from the study baseline, the PS weighted IBCFS rates at 5 years were 85% in the eET group and 78% in the non-eET group (hazard ratio [HR], 0.63 [95% CI, 0.44 to 0.89]; P 5 .0135). The PS weighted distant recurrence-free survival rates at 5 years were 91% and 83% in the eET and non-eET group, respectively (cause-specific HR, 0.49 [95% CI, 0.31 to 0.79]). In both groups, bone fractures and major cardiovascular events were reported in
1% of patients.

CONCLUSION In this cohort study analysis, extending ET in premenopausal patients with
node-positive eBC after 5 years of LHRHa treatment was associated with a
clinically meaningful reduction in both invasive and distant breast cancer
recurrences