title: Prognostic effect analysis of molecular subtype on young breast cancer patients.
abstract: OBJECTIVE
  To make a prognostic effect analysis of molecular subtype on young breast cancer patients.
  
  
  METHODS
  Totally 187 cases of young breast cancer patients less than 40 years old treated in Obstetrics and Gynecology Hospital of Fudan University between June 2005 and June 2011 were included in our study. We described their clinical-pathological characteristics, disease-free survival (DFS) rate, and overall survival (OS) rate after a median follow-up period of 61 months. The factors associated with prognosis were also evaluated by univariate and multivariate analyses.
  
  
  RESULTS
  All patients were premenopausal, with an average age of 35.36±3.88 years old. The mean tumor size was 2.43±1.53 cm. Eighty-one cases had lymph node metastasis (43.3%), 126 cases had lymphovascular invasion (67.4%), and 125 cases had histological grade III (66.8%) disease. Twenty-seven cases (14.4%) were Luminal A subtype, 99 cases (52.9%) were Luminal B subtype, 29 cases (15.5%) were human epidermal growth factor receptor 2 (HER-2) overexpression subtype, while 32 cases (17.1%) were triple negative breast cancer (TNBC) subtype according to 2013 St Gallen expert consensus. One hundred and thirty-five cases underwent mastectomy whereas 52 cases had breast-conserving surgery. One hundred and seventy-eight cases underwent adjuvant or neoadjuvant chemotherapy. Recurrence or metastasis occurred in 29 cases, 13 of which died. The 5-year DFS and OS rates were 84% and 92%. Multivariate analysis showed that nodal status (P=0.041) and molecular subtype (P=0.037) were both independent prognostic factors of DFS, while nodal status (P=0.037) and TNBC subtype (P=0.048) were both independent prognostic factors of OS.
  
  
  CONCLUSIONS
  Molecular subtype is an independent prognostic factor of young breast cancer patients. TNBC has a high risk of relapse and death.
authors.affiliation: Department of Breast Surgery, Obstetrics and Gynecology Hospital of Fudan University, Shanghai 200011, China.
authors.forename: Hong-Liang
authors.initials: HL
authors.lastname: Chen
authors.affiliation: Department of Breast Surgery, Obstetrics and Gynecology Hospital of Fudan University, Shanghai 200011, China.
authors.forename: Ang
authors.initials: A
authors.lastname: Ding
authors.affiliation: Department of Breast Surgery, Obstetrics and Gynecology Hospital of Fudan University, Shanghai 200011, China.
authors.forename: Fu-Wen
authors.initials: FW
authors.lastname: Wang
keywords: Molecular subtype; prognosis; young breast cancer