1. Tamoxifen-predictive value of gene expression signatures in premenopausal breast cancer: data from the randomized SBII:2 trial
- Author
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Lundgren, Christine, Tutzauer, Julia, Church, Sarah E., Stål, Olle, Ekholm, Maria, Forsare, Carina, Nordenskjöld, Bo, Ferno, Marten, Bendahl, Par-Ola, Ryden, Lisa, Lundgren, Christine, Tutzauer, Julia, Church, Sarah E., Stål, Olle, Ekholm, Maria, Forsare, Carina, Nordenskjöld, Bo, Ferno, Marten, Bendahl, Par-Ola, and Ryden, Lisa
- Abstract
Background: Gene expression (GEX) signatures in breast cancer provide prognostic information, but little is known about their predictive value for tamoxifen treatment. We examined the tamoxifen-predictive value and prognostic effects of different GEX signatures in premenopausal women with early breast cancer.Methods: RNA from formalin-fixed paraffin-embedded tumor tissue from premenopausal women randomized between two years of tamoxifen treatment and no systemic treatment was extracted and successfully subjected to GEX profiling (n = 437, NanoString Breast Cancer 360 (TM) panel). The median follow-up periods for a recurrence-free interval (RFi) and overall survival (OS) were 28 and 33 years, respectively. Associations between GEX signatures and tamoxifen effect were assessed in patients with estrogen receptor-positive/human epidermal growth factor receptor 2-negative (ER+ /HER2-) tumors using Kaplan-Meier estimates and Cox regression. The prognostic effects of GEX signatures were studied in the entire cohort. False discovery rate adjustments (q-values) were applied to account for multiple hypothesis testing.Results: In patients with ER+/HER2- tumors, FOXA1 expression below the median was associated with an improved effect of tamoxifen after 10 years with regard to RFi (hazard ratio [HR](FOXA1(high)) = 1.04, 95% CI = 0.61-1.76, HRFOXA1(low) = 0.30, 95% CI = 0.14-0.67, q(interaction) = 0.0013), and a resembling trend was observed for AR (HRAR(high) = 1.15, 95% CI = 0.60-2.20, HRAR(low) = 0.42, 95% CI = 0.24-0.75, q(interaction) = 0.87). Similar patterns were observed for OS. Tamoxifen was in the same subgroup most beneficial for RFi in patients with low ESR1 expression (HRRFi ESR1(high) = 0.76, 95% CI = 0.43-1.35, HRRFi, ESR1(low) = 0.56, 95% CI = 0.29-1.06, q(interaction) = 0.37). Irrespective of molecular subtype, higher levels of ESR1, Mast cel, Funding Agencies|Lund University; Swedish Cancer Society [19 0388Pj, 22 2137Pj]; Anna and Edwin Berger Foundation [2019-2022]; Governmental Funding of Clinical Research within the Swedish National Health Service [2022-40304]; Bertha Kamprad Foundation [FBKS-2021-11]; Percy Falk Foundation; Futurum-the Academy for Health and Care, Region Jonkoping County
- Published
- 2023
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