Wednesday, December 03, 2025 MAC4 /MAC5 - Assessment of adjuvant endocrine therapy with ovarian function suppression by Breast Cancer Index In this prognostic study of 1782 patients from a clinical trial, patients with tumors in which the expression of HOXB13 relative to IL17BR was low (BCI [H/I]–low) derived an absolute benefit of 6.6% in 12-year breast cancer–free interval from exemestane plus OFS vs tamoxifen plus OFS and those with BCI (H/I)–high tumors had a 6.3% absolute benefit, but with variable relative treatment effects across clinical subgroups and over time. BCI was reconfirmed to be prognostic in the study population. O’Regan RM, Ren Y, Zhang Y, Siuliukina N, Schnabel CA, Kammler R, Viale G, Dell’Orto P, Munzone E, Láng I, Tondini C, Gomez HL, Chini C, Nicoletti SVL, Puglisi F, Zaman K, Goetz MP, Stearns V, Martino S, Salim M, Loibl S, Geyer CE, Bonnefoi HR, Ciruelos EM, Loi S, Colleoni M, Fleming GF, Francis PA, Walley BA, Pagani O, Treuner K, Regan MM. Assessment of Adjuvant Endocrine Therapy With Ovarian Function Suppression by Breast Cancer Index JAMA Network Open 8: e2540931-e2540931. 2025. https://doi.org/10.1001/jamanetworkopen.2025.40931
