title: Outcome of pure mucinous breast carcinoma compared to infiltrating ductal carcinoma: a population-based study from China.
abstract: OBJECTIVE
  Pure mucinous breast carcinoma (PMBC) is a rare pathologic finding. Few studies have addressed the biologic features of PMBC and prognostic factors among patients with this disease. We performed a study to compare PMBC and invasive ductal carcinoma (IDC) by means of a large database to reliably assess the biologic phenotype and clinical behavior of PMBC.
  
  
  METHODS
  A total of 2,511 patients who met the inclusion criteria were identified from 1999 to 2010; 2,202 patients had pure IDC and 309 had PMBC. Clinical and biologic features, overall survival, and recurrence/metastasis-free survival (RFS) were compared for both groups.
  
  
  RESULTS
  PMBC had favorable characteristics including smaller size, lower rates of lymph node positivity, lower stage, higher expression of hormone receptors, and less HER2 overexpression. Patients with PMBC had better 10-year RFS (71 %) than patients with IDC (64 %). Multivariate analysis revealed that node status and tumor, node, metastasis system (TNM) stage were statistically significant prognostic factors for survival. RFS curves stratified for node status revealed a highly significant difference between node negative and node positive patients. Additionally, patients with PMBC underwent breast-conserving surgery (BCS) more frequently than patients with IDC, and the 5-year overall survival rate of the BCS group was not significantly different from the total mastectomy group.
  
  
  CONCLUSIONS
  PMBC in Chinese women showed less aggressive behavior and had a better prognosis than IDC, and this favorable outcome was maintained after 10 years. Node status and TNM stage appeared to be the most significant predictors of worse prognosis. BCS should be preferred over mastectomy in the treatment of early-stage PMBC.
authors.affiliation: Breast Cancer Institute, Cancer Hospital/Cancer Institute, Fudan University, Shanghai, People's Republic of China.
authors.forename: A-Yong
authors.initials: AY
authors.lastname: Cao
authors.forename: Min
authors.initials: M
authors.lastname: He
authors.forename: Zhe-Bin
authors.initials: ZB
authors.lastname: Liu
authors.forename: Gen-Hong
authors.initials: GH
authors.lastname: Di
authors.forename: Jiong
authors.initials: J
authors.lastname: Wu
authors.forename: Jin-Song
authors.initials: JS
authors.lastname: Lu
authors.forename: Guang-Yu
authors.initials: GY
authors.lastname: Liu
authors.forename: Zhen-Zhou
authors.initials: ZZ
authors.lastname: Shen
authors.forename: Zhi-Ming
authors.initials: ZM
authors.lastname: Shao
mesh_terms: D002288:Adenocarcinoma, Mucinous / Q000378:metabolism / Q000473:pathology* / Q000556:secondary / Q000628:therapy; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000378:metabolism / Q000473:pathology* / Q000628:therapy; D018270:Carcinoma, Ductal, Breast / Q000378:metabolism / Q000473:pathology* / Q000556:secondary / Q000628:therapy; D017024:Chemotherapy, Adjuvant; D002681:China; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008207:Lymphatic Metastasis; D015412:Mastectomy, Segmental; D008875:Middle Aged; D015999:Multivariate Analysis; D009367:Neoplasm Staging; D016016:Proportional Hazards Models; D018714:Radiotherapy, Adjuvant; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism; D011960:Receptors, Estrogen / Q000378:metabolism; D011980:Receptors, Progesterone / Q000378:metabolism; D012189:Retrospective Studies; D055815:Young Adult
chemical_list: D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; C508053:ERBB2 protein, human