title: Multifocality and multicentricity in breast cancer and survival outcomes.
abstract: BACKGROUND
  The clinicopathological characteristics and the prognostic significance of multifocal (MF) and multicentric (MC) breast cancers are not well established.
  
  
  METHODS
  MF and MC were defined as more than one lesion in the same quadrant or in separate quadrants, respectively. The Kaplan-Meier product limit was used to calculate recurrence-free survival (RFS), breast cancer-specific survival (BCSS), and overall survival (OS). Cox proportional hazards models were fit to determine independent associations of MF/MC disease with survival outcomes.
  
  
  RESULTS
  Of 3924 patients, 942 (24%) had MF (n = 695) or MC (n = 247) disease. MF/MC disease was associated with higher T stages (T2: 26% versus 21.6%; T3: 7.4% versus 2.3%, P < 0.001), grade 3 disease (44% versus 38.2%, P < 0.001), lymphovascular invasion (26.2% versus 19.3%, P < 0.001), and lymph node metastases (43.1% versus 27.3%, P < 0.001). MC, but not MF, breast cancers were associated with a worse 5-year RFS (90% versus 95%, P = 0.02) and BCSS (95% versus 97%, P = 0.01). Multivariate analysis shows that MF or MC did not have an independent impact on RFS, BCSS, or OS.
  
  
  CONCLUSIONS
  MF/MC breast cancers were associated with poor prognostic factors, but were not independent predictors of worse survival outcomes. Our findings support the current TNM staging system of using the diameter of the largest lesion to assign T stage.
authors: Division of Cancer Medicine, The University of Texas MD Anderson Cancer Center, Houston, USA.
authors: S P
authors: SP
authors: Lynch
authors: Departments of Biostatistics, The University of Texas MD Anderson Cancer Center, Houston, USA.
authors: X
authors: X
authors: Lei
authors: Breast Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, USA.
authors: M
authors: M
authors: Chavez-MacGregor
authors: Breast Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, USA.
authors: L
authors: L
authors: Hsu
authors: Surgical Oncology, The University of Texas MD Anderson Cancer Center, Houston, USA.
authors: F
authors: F
authors: Meric-Bernstam
authors: Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, USA.
authors: T A
authors: TA
authors: Buchholz
authors: Pathology, The University of Texas MD Anderson Cancer Center, Houston, USA.
authors: A
authors: A
authors: Zhang
authors: Breast Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, USA.
authors: G N
authors: GN
authors: Hortobagyi
authors: Breast Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, USA.
authors: V
authors: V
authors: Valero
authors: Breast Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, USA; Systems Biology, The University of Texas MD Anderson Cancer Center, Houston, USA. Electronic address: agonzalez@mdanderson.org.
authors: A M
authors: AM
authors: Gonzalez-Angulo
mesh_terms: D001943:Breast Neoplasms / Q000188:drug therapy / Q000401:mortality*; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008207:Lymphatic Metastasis; D015999:Multivariate Analysis; D009362:Neoplasm Metastasis; D009367:Neoplasm Staging; D011379:Prognosis; D016016:Proportional Hazards Models; D016019:Survival Analysis; D016896:Treatment Outcome