title: Clinical significance of the sub-classification of 71 cases mucinous breast carcinoma.
abstract: OBJECTIVE
  Mucinous breast carcinoma (MBC) is classified into mixed mucinous breast carcinoma (MMBC) and pure mucinous breast carcinoma (PMBC) based on whether the tumor is with or without a component of invasive ductal carcinoma, respectively. PMBC is subtyped into hypocellular PMBC (PMBC-A) and hypercellular PMBC (PMBC-B).
  
  
  METHODS
  Of 1,760 primary breast carcinomas, 71 were diagnosed as MBC, and were subtyped for comparison purposes.
  
  
  RESULTS
  Seventy-one of all breast cancers (4.0%) were MBC, and consisted of 23 MMBC, 32 PMBC-A and 16 PMBC-B. The MBC tumors were more often hormone receptor-positive and HER2-negative than non-MBC tumors. Patients with MMBC, PMBC-B or PMBC-A, in this order, had significantly higher recurrence rates than non-MBC cases (p=0.006, log-rank).
  
  
  CONCLUSIONS
  In the NCCN guidelines, MBC is also regarded as "a histological type with a favorable prognosis" in a uniform manner, and "treatment for a histological type with a favorable prognosis" is recommended. However, the results of this study suggest that sub-classification-based, individualized therapeutic strategies should be considered.
authors.affiliation: Department of Surgical Oncology, Osaka City University Graduate School of Medicine, 1-4-3 Asahi-machi, Abeno-ku, Osaka, Japan.
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Kashiwagi
authors.forename: Naoyoshi
authors.initials: N
authors.lastname: Onoda
authors.forename: Yuka
authors.initials: Y
authors.lastname: Asano
authors.forename: Satoru
authors.initials: S
authors.lastname: Noda
authors.forename: Hidemi
authors.initials: H
authors.lastname: Kawajiri
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Takashima
authors.forename: Masahiko
authors.initials: M
authors.lastname: Ohsawa
authors.forename: Seiichi
authors.initials: S
authors.lastname: Kitagawa
authors.forename: Kosei
authors.initials: K
authors.lastname: Hirakawa
keywords: Breast cancer; Hypercellular variant; Hypocellular variant; Mucinous breast carcinoma; Subclassification