title: Inflammatory breast cancer in the Netherlands; improved survival over the last decades.
abstract: Locally advanced breast cancer (LABC) includes inflammatory breast cancer (IBC) as well as non-inflammatory LABC (NI-LABC). The aim of this population-based study was to compare the tumour characteristics, treatment and relative survival of IBC and NI-LABC patients.
  
  
  
  Patients with either IBC (cT4d) or NI-LABC (cT4a-c) were identified from the nationwide Netherlands Cancer Registry from the period 1989-2015. In each group, patients are divided into three time periods in order to perform a trend analysis: 1989-1997, 1998-2006, and 2007-2015.
  
  
  
  IBC comprised 1.1% and NI-LABC 4.6% of all diagnosed breast cancer patients. IBC patients showed more nodal metastases (77.8 vs. 69.7%, P < 0.001) and distant metastases (39.7 vs. 34.1%, P < 0.001). IBC tumours were more often triple negative (23.2 vs. 12.8%, P < 0.001) and poorly differentiated (69.8 vs. 53.8%, P < 0.001). Trimodality therapy (neoadjuvant chemotherapy, surgery and adjuvant radiotherapy) was more often applied over time in both groups (IBC: 23.7%-56.0%-68.6%; NI-LABC: 3.7%-25.9%-43.6%; Ptrend< 0.001). In IBC patients, relative 5-year survival was significantly shorter than in patients with NI-LABC (30.2 vs. 45.1%, P < 0.001). The relative survival significantly improved for IBC from 17.2% (1989-1997) to 30.0 and 38.9% for the last two time periods (1998-2006: P < 0.001; 2007-2015: P < 0.001). In contrast, survival did not significantly improve in NI-LABC breast cancer: from 44.7% (1989-1997) to 44.0 and 48.4% (1998-2006: P = 0.483; 2007-2015: P = 0.091).
  
  
  
  IBC has tumour characteristics that determine its aggressive biology compared to NI-LABC. Trimodality therapy was increasingly applied in both groups, but did not improve survival in NI-LABC. Although relative survival in IBC patients has improved during the last decades, it remains a disease with a dismal prognosis.
authors.affiliation: Department of Surgical Oncology, Radboud University Medical Center Nijmegen, Geert Grootplein Zuid 10, 6525 GA, Nijmegen, The Netherlands. djpvanuden@gmail.com.
authors.forename: D J P
authors.identifier: 0000-0001-7479-9335
authors.initials: DJ
authors.lastname: van Uden
authors.affiliation: Department of Research, Netherlands Comprehensive Cancer Organisation (IKNL), Utrecht, Hoog Catharijne, Godebaldkwartier 419, 3511 DT, Utrecht, The Netherlands.
authors.forename: R
authors.initials: R
authors.lastname: Bretveld
authors.affiliation: Department of Research, Netherlands Comprehensive Cancer Organisation (IKNL), Utrecht, Hoog Catharijne, Godebaldkwartier 419, 3511 DT, Utrecht, The Netherlands.|Department of Health Technology and Services Research, MIRA Institute for Biomedical Technology and Technical Medicine, Drienerlolaan 5, 7522 NB, Enschede, The Netherlands.
authors.forename: S
authors.initials: S
authors.lastname: Siesling
authors.affiliation: Department of Surgical Oncology, Radboud University Medical Center Nijmegen, Geert Grootplein Zuid 10, 6525 GA, Nijmegen, The Netherlands.
authors.forename: J H W
authors.initials: JH
authors.lastname: de Wilt
authors.affiliation: Department of Surgery, Rijnstate Hospital, Arnhem, Wagnerlaan 55, 6815 AD, Arnhem, The Netherlands.
authors.forename: C F J M
authors.initials: CF
authors.lastname: Blanken-Peeters
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor; D003131:Combined Modality Therapy; D005260:Female; D006801:Humans; D058922:Inflammatory Breast Neoplasms / Q000175:diagnosis / Q000453:epidemiology* / Q000401:mortality / Q000628:therapy; D008875:Middle Aged; D060787:Neoplasm Grading; D009362:Neoplasm Metastasis; D009367:Neoplasm Staging; D009426:Netherlands / Q000453:epidemiology; D011159:Population Surveillance; D015996:Survival Rate; D016896:Treatment Outcome
chemical_list: D014408:Biomarkers, Tumor
keywords: Epidemiology; Inflammatory breast cancer; Locally advanced breast cancer; Survival; The Netherlands; Treatment