title: Inflammatory Breast Cancer: A Distinct Clinicopathological Entity Transcending Histological Distinction.
abstract: BACKGROUND
  Although well recognized in breast oncology literature, histologic subtypes have not been previously described in inflammatory breast cancer (IBC). The purpose of this study was to describe lobular subtype in IBC and assess the impact of histology on patient outcomes.
  
  
  METHODS
  We performed a retrospective analysis of 659 IBC patients at MD Anderson Cancer Center between January 1984 and December 2009. Patients with Invasive Lobular, Mixed Invasive Ductal and Lobular, or Invasive Ducal Carcinomas (ILC, MIC, IDC, respectively) comprise the subject of this report. Patient characteristics and survival estimates were compared by using chi-square test and Kaplan-Meier method with log-rank statistic. Cox proportional hazards models were fit to determine association of histology with outcomes after adjustment for other characteristics.
  
  
  RESULTS
  A total of 30, 37, and 592 patients were seen to have invasive lobular, mixed, or ductal histology, respectively. Grade 3 tumors were more common in the ductal group (78%) than in the lobular (60%) or mixed (61%) group (P = 0.01). The 3-year overall survival rates were 68%, 64%, and 62% in the lobular, mixed, and ductal groups, respectively (P = 0.68). After adjustment, histology did not have a significant effect on death in the lobular group (HR = 0.70, 95% confidence interval [CI]: 0.26-1.94; P = 0.50) or mixed group (HR = 0.53, 95% CI: 0.25-1.13; P = 0.10) compared with the ductal group.
  
  
  CONCLUSIONS
  In this cohort of IBC patients, lobular histology was seen in 4.5% cases. Histology does not appear to have a significant effect on survival outcomes in IBC patients, unlike in patients with non-inflammatory breast cancer (n-IBC), indicating the distinct biological behavior of the IBC phenotype.
authors.affiliation: Department of Gastrointestinal Medical Oncology, Divison of Cancer Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas, United States of America.
authors.forename: K
authors.initials: K
authors.lastname: Raghav
authors.affiliation: Division of Cancer Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas, United States of America.
authors.forename: J T
authors.initials: JT
authors.lastname: French
authors.affiliation: Department of Breast Medical Oncology, Divison of Cancer Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas, United States of America.|Department of Morgan Welch Inflammatory Breast Cancer Research Program and Clinic, Divison of Cancer Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas, United States of America.
authors.forename: N T
authors.initials: NT
authors.lastname: Ueno
authors.affiliation: Department of Biostatistics, Divison of Cancer Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas, United States of America.
authors.forename: X
authors.initials: X
authors.lastname: Lei
authors.affiliation: Department of Pathology, Divison of Cancer Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas, United States of America.
authors.forename: S
authors.initials: S
authors.lastname: Krishnamurthy
authors.affiliation: Department of Hematopathology, Divison of Cancer Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas, United States of America.
authors.forename: J M
authors.initials: JM
authors.lastname: Reuben
authors.affiliation: Department of Breast Medical Oncology, Divison of Cancer Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas, United States of America.
authors.forename: V
authors.initials: V
authors.lastname: Valero
authors.affiliation: Department of Breast Medical Oncology, Divison of Cancer Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas, United States of America.
authors.forename: N K
authors.initials: NK
authors.lastname: Ibrahim
mesh_terms: D000368:Aged; D018270:Carcinoma, Ductal, Breast / Q000175:diagnosis / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D018275:Carcinoma, Lobular / Q000175:diagnosis / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D005260:Female; D006651:Histocytochemistry; D006801:Humans; D058922:Inflammatory Breast Neoplasms / Q000175:diagnosis / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D008207:Lymphatic Metastasis; D008408:Mastectomy; D008875:Middle Aged; D060787:Neoplasm Grading; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D010641:Phenotype; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D015996:Survival Rate; D016896:Treatment Outcome