title: Prognostic model for advanced breast carcinoma with luminal subtype and impact of hormonal maintenance: Implications for post-progression and conditional survival.
abstract: BACKGROUND
  The aim of this analysis was to develop and validate a prognostic model for advanced breast cancer (ABC) with luminal subtype based on the combination of clinical, pathological and therapeutic predictors to provide a practical tool to evaluate patients' prognosis.
  
  
  METHODS
  Clinical and pathological data were retrospectively correlated to progression-free and overall survival (PFS/OS) using a Cox model. Significant treatment variables were adjusted with the propensity score analysis. A continuous score to identify risk classes was derived according to model ratios. The performance of the risk-class model was tested for post-progression survival (PPS) and conditional survival (CS) as well.
  
  
  RESULTS
  Data from 335 patients (3 institutions) were gathered (median follow-up 58 months). At multivariate analysis Ki67, Performance Status (PS) and number of metastatic sites were significant predictors for PFS, whereas Ki67, PS, brain metastases, PFS after 1st-line therapy, number of chemotherapy lines, hormonal therapy and maintenance were significant predictors for OS. The hormonal maintenance resulted to be prognostic after adjustment with propensity score analysis. A two-class model significantly differentiated low-risk and high-risk patients for 2-year PFS (31.5% and 11.0%, p < 0.0001), and 3-years OS (57.1% and 4.8%, p < 0.0001). A three-class model separated low risk, intermediate-risk, and high-risk patients for 2-year PFS (40.8%, 24.4%, and 11.0%, p < 0.0001) and 3-year OS (68.1%, 24.8%, and 4.8%, p < 0.0001). Both models equally discriminate the luminal ABC prognosis in terms of PPS and CS.
  
  
  CONCLUSIONS
  A risk stratification model including 'easy-to-obtain' clinical, pathological and therapeutic parameters accurately separates luminal ABC patients into different risk classes.
authors.affiliation: Medical Oncology, University of Verona, Azienda Ospedaliera Universitaria Integrata, Verona, Italy; Breast Unit, Azienda Ospedaliera Universitaria Integrata, Verona, Italy.
authors.forename: Luisa
authors.initials: L
authors.lastname: Carbognin
authors.affiliation: Biostatistics, 'Regina Elena' National Cancer Institute, Roma, Italy.
authors.forename: Isabella
authors.initials: I
authors.lastname: Sperduti
authors.affiliation: Medical Oncology, 'Vito Fazzi' Hospital, Lecce, Italy.
authors.forename: Mariangela
authors.initials: M
authors.lastname: Ciccarese
authors.affiliation: Medical Oncology 'A', 'Regina Elena' National Cancer Institute, Roma, Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Fabi
authors.affiliation: Medical Oncology, 'Vito Fazzi' Hospital, Lecce, Italy.
authors.forename: Luciana
authors.initials: L
authors.lastname: Petrucelli
authors.affiliation: Medical Oncology 'A', 'Regina Elena' National Cancer Institute, Roma, Italy.
authors.forename: Sabrina
authors.initials: S
authors.lastname: Vari
authors.affiliation: Medical Oncology, 'Vito Fazzi' Hospital, Lecce, Italy.
authors.forename: Rosa Chiara
authors.initials: RC
authors.lastname: Forcignanò
authors.affiliation: Medical Oncology, University of Verona, Azienda Ospedaliera Universitaria Integrata, Verona, Italy; Breast Unit, Azienda Ospedaliera Universitaria Integrata, Verona, Italy.
authors.forename: Rolando
authors.initials: R
authors.lastname: Nortilli
authors.affiliation: Medical Oncology, University of Verona, Azienda Ospedaliera Universitaria Integrata, Verona, Italy.
authors.forename: Cecilia
authors.initials: C
authors.lastname: Vicentini
authors.affiliation: Medical Oncology, University of Verona, Azienda Ospedaliera Universitaria Integrata, Verona, Italy.
authors.forename: Sara
authors.initials: S
authors.lastname: Pilotto
authors.affiliation: Medical Oncology, University of Verona, Azienda Ospedaliera Universitaria Integrata, Verona, Italy.
authors.forename: Sara
authors.initials: S
authors.lastname: Merler
authors.affiliation: Medical Oncology, University of Verona, Azienda Ospedaliera Universitaria Integrata, Verona, Italy.
authors.forename: Ilaria
authors.initials: I
authors.lastname: Zampiva
authors.affiliation: Breast Unit, Azienda Ospedaliera Universitaria Integrata, Verona, Italy; Department of Pathology and Diagnostics, University of Verona, Azienda Ospedaliera Universitaria Integrata, Verona, Italy.
authors.forename: Matteo
authors.initials: M
authors.lastname: Brunelli
authors.affiliation: Breast Unit, Azienda Ospedaliera Universitaria Integrata, Verona, Italy; Department of Pathology and Diagnostics, University of Verona, Azienda Ospedaliera Universitaria Integrata, Verona, Italy.
authors.forename: Erminia
authors.initials: E
authors.lastname: Manfrin
authors.affiliation: Biostatistics, 'Regina Elena' National Cancer Institute, Roma, Italy.
authors.forename: Diana
authors.initials: D
authors.lastname: Giannarelli
authors.affiliation: Medical Oncology, University of Verona, Azienda Ospedaliera Universitaria Integrata, Verona, Italy; Breast Unit, Azienda Ospedaliera Universitaria Integrata, Verona, Italy.
authors.forename: Giampaolo
authors.initials: G
authors.lastname: Tortora
authors.affiliation: Medical Oncology, University of Verona, Azienda Ospedaliera Universitaria Integrata, Verona, Italy; Breast Unit, Azienda Ospedaliera Universitaria Integrata, Verona, Italy. Electronic address: emilio.bria@univr.it.
authors.forename: Emilio
authors.initials: E
authors.lastname: Bria
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018931:Antineoplastic Agents, Hormonal / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000188:drug therapy / Q000401:mortality* / Q000473:pathology; D018450:Disease Progression; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D060046:Maintenance Chemotherapy / Q000379:methods; D008875:Middle Aged; D015999:Multivariate Analysis; D049451:Nomograms; D057216:Propensity Score; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D018570:Risk Assessment / Q000379:methods*; D016019:Survival Analysis
chemical_list: D018931:Antineoplastic Agents, Hormonal
keywords: Advanced breast; Breast cancer; Luminal; Prognosis