Author:
Lundgren Christine,Tutzauer Julia,Church Sarah E.,Stål Olle,Ekholm Maria,Forsare Carina,Nordenskjöld Bo,Fernö Mårten,Bendahl Pär-Ola,Rydén Lisa
Abstract
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™ 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, qinteraction = 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, qinteraction = 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, qinteraction = 0.37). Irrespective of molecular subtype, higher levels of ESR1, Mast cells, and PGR on a continuous scale were correlated with improved 10 years RFi (HRESR1 = 0.80, 95% CI = 0.69–0.92, q = 0.005; HRMast cells = 0.74, 95% CI = 0.65–0.85, q < 0.0001; and HRPGR = 0.78, 95% CI = 0.68–0.89, q = 0.002). For BC proliferation and Hypoxia, higher scores associated with worse outcomes (HRBCproliferation = 1.54, 95% CI = 1.33–1.79, q < 0.0001; HRHypoxia = 1.38, 95% CI = 1.20–1.58, q < 0.0001). The results were similar for OS.
Conclusions
Expression of FOXA1 is a promising predictive biomarker for tamoxifen effect in ER+/HER2− premenopausal breast cancer. In addition, each of the signatures BC proliferation, Hypoxia, Mast cells, and the GEX of AR, ESR1, and PGR had prognostic value, also after adjusting for established prognostic factors.
Trial registration This trial was retrospectively registered in the ISRCTN database the 6th of December 2019, trial ID: https://clinicaltrials.gov/ct2/show/ISRCTN12474687.
Funder
The Percy Falk Foundation
Futurum – the Academy for Health and Care, Region Jönköping County
The Swedish Cancer Society
The Anna and Edwin Berger Foundation
Governmental Funding of Clinical Research within the Swedish National Health Service
The Bertha Kamprad Foundation
Lund University
Publisher
Springer Science and Business Media LLC