title: Comparison of clinical outcomes between luminal invasive ductal carcinoma and luminal invasive lobular carcinoma.
abstract: BACKGROUND
  The pathological and clinical features of invasive lobular carcinoma (ILC) differ from those of invasive ductal carcinoma (IDC). Several studies have indicated that patients with ILC have a better prognosis than those with ductal carcinoma. However, no previous study has considered the molecular subtypes and histological subtypes of ILC. We compared prognosis between IDC and classical, luminal type ILC and developed prognostic factors for early breast cancer patients with classical luminal ILC.
  
  
  METHODS
  Four thousand one hundred ten breast cancer patients were treated at the Aichi Cancer Center Hospital from 2003 to 2012. We identified 1,661 cases with luminal IDC and 105 cases with luminal classical ILC. We examined baseline characteristics, clinical outcomes, and prognostic factors of luminal ILC.
  
  
  RESULTS
  The prognosis of luminal ILC was significantly worse than that of luminal IDC. The rates of 5-year disease free survival (DFS) were 91.9% and 88.4% for patients with luminal IDC and luminal ILC, respectively (P = 0.008). The rates of 5-year overall survival (OS) were 97.6% and 93.1% for patients with luminal IDC and luminal ILC respectively (P = 0.030). Although we analyzed prognosis according to stratification by tumor size, luminal ILC tended to have worse DFS than luminal IDC in the large tumor group. In addition, although our analysis was performed according to matching lymph node status, luminal ILC had a significantly worse DFS and OS than luminal IDC in node-positive patients. Survival curves showed that the prognosis for ILC became worse than IDC over time. Multivariate analysis showed that ILC was an important factor related to higher risk of recurrence of luminal type breast cancer, even when tumor size, lymph node status and histological grade were considered.
  
  
  CONCLUSIONS
  Luminal ILC had worse outcomes than luminal IDC. Consequently, different treatment approaches should be used for luminal ILC than for luminal IDC.
authors.affiliation: Department of Breast Oncology, Aichi Cancer Center Hospital, 1-1, Kanokoden, Chikusaku, Nagoya, 464-8681, Japan.|Department of Transplantation and Endocrine Surgery, Nagoya University Graduate School of Medicine, 65 Tsurumai, Showaku, Nagoya, 466-8560, Japan.
authors.forename: Yayoi
authors.initials: Y
authors.lastname: Adachi
authors.affiliation: Department of Breast Oncology, Aichi Cancer Center Hospital, 1-1, Kanokoden, Chikusaku, Nagoya, 464-8681, Japan.
authors.forename: Junko
authors.initials: J
authors.lastname: Ishiguro
authors.affiliation: Department of Breast Oncology, Aichi Cancer Center Hospital, 1-1, Kanokoden, Chikusaku, Nagoya, 464-8681, Japan.
authors.forename: Haruru
authors.initials: H
authors.lastname: Kotani
authors.affiliation: Department of Breast Oncology, Aichi Cancer Center Hospital, 1-1, Kanokoden, Chikusaku, Nagoya, 464-8681, Japan.
authors.forename: Tomoka
authors.initials: T
authors.lastname: Hisada
authors.affiliation: Department of Breast Oncology, Aichi Cancer Center Hospital, 1-1, Kanokoden, Chikusaku, Nagoya, 464-8681, Japan.
authors.forename: Mari
authors.initials: M
authors.lastname: Ichikawa
authors.affiliation: Department of Breast Oncology, Aichi Cancer Center Hospital, 1-1, Kanokoden, Chikusaku, Nagoya, 464-8681, Japan.
authors.forename: Naomi
authors.initials: N
authors.lastname: Gondo
authors.affiliation: Department of Breast Oncology, Aichi Cancer Center Hospital, 1-1, Kanokoden, Chikusaku, Nagoya, 464-8681, Japan.
authors.forename: Akiyo
authors.initials: A
authors.lastname: Yoshimura
authors.affiliation: Department of Breast Oncology, Aichi Cancer Center Hospital, 1-1, Kanokoden, Chikusaku, Nagoya, 464-8681, Japan.
authors.forename: Naoto
authors.initials: N
authors.lastname: Kondo
authors.affiliation: Department of Breast Oncology, Aichi Cancer Center Hospital, 1-1, Kanokoden, Chikusaku, Nagoya, 464-8681, Japan.
authors.forename: Masaya
authors.initials: M
authors.lastname: Hattori
authors.affiliation: Department of Breast Oncology, Aichi Cancer Center Hospital, 1-1, Kanokoden, Chikusaku, Nagoya, 464-8681, Japan.
authors.forename: Masataka
authors.initials: M
authors.lastname: Sawaki
authors.affiliation: Department of Breast Oncology, Aichi Cancer Center Hospital, 1-1, Kanokoden, Chikusaku, Nagoya, 464-8681, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Fujita
authors.affiliation: Department of Transplantation and Endocrine Surgery, Nagoya University Graduate School of Medicine, 65 Tsurumai, Showaku, Nagoya, 466-8560, Japan.
authors.forename: Toyone
authors.initials: T
authors.lastname: Kikumori
authors.affiliation: Department of Pathology and Molecular Diagnostics, Aichi Cancer Center Hospital, 1-1, Kanokoden, Chikusaku, Nagoya, 464-8681, Japan.
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Yatabe
authors.affiliation: Department of Gastroenterological Surgery, Nagoya University Graduate School of Medicine, 65 Tsurumai, Showaku, Nagoya, Aichi, 466-8560, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Kodera
authors.affiliation: Department of Breast Oncology, Aichi Cancer Center Hospital, 1-1, Kanokoden, Chikusaku, Nagoya, 464-8681, Japan. hiwata@aichi-cc.jp.
authors.forename: Hiroji
authors.initials: H
authors.lastname: Iwata
mesh_terms: D000368:Aged; D001943:Breast Neoplasms / Q000145:classification / Q000188:drug therapy / Q000453:epidemiology / Q000473:pathology*; D018270:Carcinoma, Ductal, Breast / Q000145:classification / Q000188:drug therapy / Q000453:epidemiology / Q000473:pathology*; D018275:Carcinoma, Lobular / Q000145:classification / Q000188:drug therapy / Q000453:epidemiology / Q000473:pathology*; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000145:classification / Q000188:drug therapy / Q000453:epidemiology / Q000473:pathology*; D009367:Neoplasm Staging; D011379:Prognosis; D016896:Treatment Outcome
keywords: Invasive ductal carcinoma; Invasive lobular carcinoma; Luminal; Prognosis