Role of androgen receptor expression in early stage ER+/PgR-/HER2-breast cancer
THERAPEUTIC ADVANCES IN MEDICAL ONCOLOGY
Authors: Tagliaferri, Barbara; Quaquarini, Erica; Palumbo, Raffaella; Balletti, Emanuela; Presti, Daniele; Malovini, Alberto; Agozzino, Manuela; Teragni, Cristina Maria; Terzoni, Andrea; Bernardo, Antonio; Villani, Laura; Sottotetti, Federico
Abstract
Background: Progesterone receptor (PgR) negative breast cancer (BC) is an aggressive subtype with poor prognosis and reduced response to endocrine treatments. Several studies have suggested that androgen receptor (AR) expression is associated with a favorable tumor biology, longer recurrence free survival (RFS), and overall survival. In the literature no data exist regarding the role of AR expression in early stage estrogen receptor (ER)+/PgR- BCs. The aim of this study was to evaluate the prognostic role of AR expression in this setting. Patients and methods: This is a monocentric retrospective study in which 208 patients who underwent surgical intervention for ER+/PgR-/Human Epidermal growth factor Receptor 2 (HER2)- BC were included. The primary objective was to analyze the relationship between AR expression and RFS. Results: At a median follow-up of 77 months, 75 patients (36%) had a disease relapse (all sites included). AR expression was significantly higher in patients who did not relapse compared with those who relapsed with an impact on RFS (hazard ratio [HR] = 0.99,p = 0.025). Patients with AR expression > 80% had a lower risk of relapse compared with those with AR <80% (HR = 0.53,p = 0.008). In addition, breast tumors with higher AR expression had good biological features (low ki67 and nuclear grade) compared with BCs with lower AR expression, at least partly explaining the different outcome. Conclusions: The results of this study support the potential prognostic role of AR in patients with ER+/PgR- BCs and may contribute to the identification of subgroups of high-risk patients.
Calibration of systematics in constraining modified gravity models with galaxy cluster mass profiles
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
Authors: Pizzuti, L.; Sartoris, B.; Borgani, S.; Biviano, A.
Abstract
Joint lensing and dynamical mass profile determinations of galaxy clusters are an excellent tool to constrain modification of gravity at cosmological scales. However, search for tiny departures from General Relativity (GR) calls for an accurate control of the systematics affecting the method. In this analysis we concentrate on the systematics in the reconstruction of mass profiles from the dynamics of cluster member galaxies, while assuming that lensing provides unbiased mass profile reconstructions. In particular, in the case study of linear f (R) gravity, we aim at verifying whether in realistic simulations of cluster formation a spurious detection of departure from GR can be detected due to violation of the main assumptions (e.g. dynamical equilibrium and spherical symmetry) on which the method is based. We aim at identifying and calibrating the impact of those systematics by analyzing a set of Dark Matter halos taken from ACDM N-body cosmological simulations performed with the GADGET-3 code. We evaluate how the constraints on the additional degree of freedom mf(R) suffer the lack of dynamical relaxation and departures from spherical symmetry. If no selection criteria are applied, similar to 60% of clusters in a ACDM Universe (where GR is assumed) produce a spurious detection of modified gravity. We find that the probability of finding cluster in agreement with GR predictions P-GR mainly depends on the properties of the halo's projected phase-space and on shape orientation of the cluster along the line-of-sight projection. We further define two observational criteria which correlate with PGR and which can be used to select, among a generic population of galaxy clusters in the local Universe, those objects that are more suitable for the application of the proposed method. In particular, we find that according to these criteria the percentage of spurious detection can be lowered down to similar to 20% in the best case. We discuss how P-GR changes when a simplified treatment of the chameleon screening mechanism is considered. Our results are relevant in view of the availability of precise measurements of lensing mass profiles from imaging data and dynamics mass profiles from spectroscopic data that will be available with the next generation surveys.