title: Clinicopathological Characteristics of Triple-negative Breast Cancers in the Northeast Region of Turkey.
abstract: BACKGROUND
  Triple-negative (TN) breast cancer is a subtype of breast cancer characterised by a loss of estrogen receptor (ER), progesterone receptor (PR) expression, and the absence of human epidermal growth factor (HER2) overexpression.
  
  
  OBJECTIVE
  To identify the relationships between clinicopathological characteristics of TN breast cancers in the northeast region of Turkey and disease free survival (DFS) and overall survival (OS).
  
  
  METHODS
  Retrospective clinical study.
  
  
  METHODS
  Seven hundred and eighty non-metastatic breast cancer patients were enrolled in this study. The relationships between TN breast cancer and other breast cancers with respect to clinicopathological characteristics, as well as DFS and OS, were studied.
  
  
  RESULTS
  The triple-negative phenotype was detected in 204 patients (27.1%). Patients with triple-negative breast cancer had more grade 2-3 tumours compared to those with other types of breast cancer (92.5% versus 84.3%, p=0.004). Invasive ductal carcinoma histology, on the other hand, was less prevalent in patients with TN breast cancer (77% versus 84.5%, p=0.016). No significant differences were identified between the groups in other clinicopathological variables. Relapse and mortality rates were higher in the TN group during the follow-up of both groups [57 (27.9%) versus 89 (16.2%), p<0.001 for relapse; 27 (13.2%) versus 37 (6.8%), p=0.005 for mortality]. The univariate analysis demonstrated shorter DFS and OS for patients with TN breast cancer compared to those with other types of breast cancer. In the multivariate analysis, patients with TN breast cancer were 2.21 times more likely to develop relapse, while the likelihood of death increased 3.21-fold (p<0.001 and p<0.001).
  
  
  CONCLUSIONS
  Triple-negative breast cancers demonstrate a more aggressive clinical course compared to other breast cancers. More effective strategies should be developed for the treatment of this subgroup of breast cancer.
authors.affiliation: Department of Medical Oncology, Eskişehir Osmangazi University Faculty of Medicine, Eskişehir, Turkey.
authors.forename: Bülent
authors.initials: B
authors.lastname: Yıldız
authors.affiliation: Department of Medical Oncology, Konya Training and Research Hospital, Konya, Turkey.
authors.forename: Evren
authors.initials: E
authors.lastname: Fidan
authors.affiliation: Department of Medical Oncology, Karadeniz Technical University Faculty of Medicine, Trabzon, Turkey.
authors.forename: Feyyaz
authors.initials: F
authors.lastname: Ozdemir
authors.affiliation: Department of Radiation Oncology, Karadeniz Technical University Faculty of Medicine, Trabzon, Turkey.
authors.forename: Orhan
authors.initials: O
authors.lastname: Sezen
authors.affiliation: Department of Medical Oncology, Karadeniz Technical University Faculty of Medicine, Trabzon, Turkey.
authors.forename: Halil
authors.initials: H
authors.lastname: Kavgacı
authors.affiliation: Department of Medical Oncology, Karadeniz Technical University Faculty of Medicine, Trabzon, Turkey.
authors.forename: Fazıl
authors.initials: F
authors.lastname: Aydın
keywords: Breast neoplasms; disease free survival; overall survival