title: Unique clinicopathological features of metaplastic breast carcinoma compared with invasive ductal carcinoma and poor prognostic indicators.
abstract: BACKGROUND
  Metaplastic breast carcinoma is a rare aggressive malignant neoplasm. The purposes of this study are to review the pathologic features and clinical outcomes of metaplastic breast carcinoma compared to invasive ductal carcinoma and to evaluate the prognosis of metaplastic breast carcinoma.
  
  
  METHODS
  The cases of 55 patients with metaplastic breast carcinoma presenting between 1991 and 2006 were analyzed and compared to the cases of 767 age-matched patients with invasive ductal carcinoma from the same time period.
  
  
  RESULTS
  The group of patients with metaplastic breast carcinoma presented with a larger tumor size, lower lymph node involvement, higher percentage of triple-negative (estrogen receptor-, progesterone receptor- and human epidermal growth factor receptor-2-negative) cases, and Ki-67 over-expression compared with the group of patients with invasive ductal carcinoma and triple-negative invasive ductal carcinomas. Patients in the metaplastic breast carcinoma group tended to have more local (often chest wall) recurrences (P = 0.038) and distant (often lung) metastases (P = 0.001) than those in the invasive ductal carcinomas group. The prognosis of metaplastic breast carcinoma was poorer than that of invasive ductal carcinoma and triple-negative invasive ductal carcinomas; the 5-year overall survival rate was 54.5% in metaplastic breast carcinoma versus 85.1% in invasive ductal carcinoma, and 73.3% in triple-negative invasive ductal carcinomas (P <0.001). The 5-year disease-free survival rate was 45.5% in metaplastic breast carcinoma versus 71.2% in invasive ductal carcinoma, and 60.3% in triple-negative invasive ductal carcinomas (P <0.001). Multivariate analysis revealed tumor size larger than 5.0 cm, lymph node involvement and Ki-67≥14% were significantly related to 5-year overall survival (P = 0.010; P = 0.010; P = 0.035) and 5-year disease-free survival (P = 0.020; P = 0.018; P = 0.049).
  
  
  CONCLUSIONS
  Metaplastic breast carcinoma shows a poorer prognosis than both invasive ductal carcinoma and triple-negative invasive ductal carcinomas. Tumor size larger than 5.0 cm, lymph node involvement and Ki-67 ≥14% indicate a poor prognosis in patients with metaplastic breast carcinoma.
authors.affiliation: Department of Breast Surgery, The Third Affiliated Hospital of Harbin Medical University, 150 Haping Road, Harbin 150081, China.
authors.forename: Yanni
authors.initials: Y
authors.lastname: Song
authors.forename: Xiaolong
authors.initials: X
authors.lastname: Liu
authors.forename: Guoqiang
authors.initials: G
authors.lastname: Zhang
authors.forename: Hongtao
authors.initials: H
authors.lastname: Song
authors.forename: Yanlv
authors.initials: Y
authors.lastname: Ren
authors.forename: Xiaoguang
authors.initials: X
authors.lastname: He
authors.forename: Yanbo
authors.initials: Y
authors.lastname: Wang
authors.forename: Jinfeng
authors.initials: J
authors.lastname: Zhang
authors.forename: Youxue
authors.initials: Y
authors.lastname: Zhang
authors.forename: Shanshan
authors.initials: S
authors.lastname: Sun
authors.forename: Xiaoshuan
authors.initials: X
authors.lastname: Liang
authors.forename: Qian
authors.initials: Q
authors.lastname: Sun
authors.forename: Da
authors.initials: D
authors.lastname: Pang
mesh_terms: D000230:Adenocarcinoma / Q000401:mortality / Q000473:pathology / Q000628:therapy; D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000378:metabolism; D001943:Breast Neoplasms / Q000401:mortality* / Q000473:pathology / Q000628:therapy; D018270:Carcinoma, Ductal, Breast / Q000401:mortality* / Q000473:pathology / Q000628:therapy; D002294:Carcinoma, Squamous Cell / Q000401:mortality / Q000473:pathology / Q000628:therapy; D016022:Case-Control Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008679:Metaplasia / Q000401:mortality* / Q000473:pathology / Q000628:therapy; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000401:mortality* / Q000473:pathology / Q000628:therapy; D009367:Neoplasm Staging; D011379:Prognosis; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism; D011960:Receptors, Estrogen / Q000378:metabolism; D011980:Receptors, Progesterone / Q000378:metabolism; D015996:Survival Rate; D055815:Young Adult
chemical_list: D014408:Biomarkers, Tumor; D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone