Aggressive Intrinsic Subtypes in Breast Cancer: A Predictor of Guideline Adherence in Older Patients With Breast Cancer?
BACKGROUND
Treatment side effects, comorbidities, and guideline-adherent treatment (GL+) influence the oncologic outcome of older breast cancer patients (oBCP) (age ≥ 70 years). The focus of this analysis was to investigate the associations among tumor characteristics, guideline adherence, and outcome and to compare these associations between younger breast cancer patients (yBCP) (age 50-69 years) and oBCP.


METHODS
This is a retrospective multicenter cohort study with 17 participating certified breast cancer centers. The analysis of 10,897 patient records collected from 1992 to 2008 for GL+ and clinical outcome was performed. Tumor and patient characteristics and their associations with GL+ were compared between oBCP and yBCP.


RESULTS
Nonguideline-adherent treatment (GL-) was associated with higher tumor stages and comorbidities. This effect was stronger in the oBCP group (P < .001). GL+ was significantly more common in yBCP than in oBCP (P < .001). The oBCP had significantly higher tumor stages, including tumor size (P < .001), nodal status (P < .001), and positive hormone receptors (P = .001). Tumor grading was lower (P = .001), and HER2neu overexpression was less frequent (P = .003) in oBCP. Overall survival and disease-free survival are significantly impaired if GL- occurred in patients with breast cancer independently of age.


CONCLUSIONS
GL- is associated with decreased disease-free survival and overall survival in both age groups. GL+ decreases advanced tumor characteristics in all age groups but significantly more in oBCP. If patients received GL+, we were unable to detect a statistical significant difference in the survival parameters.
Universität Ulm, Klinik für Frauenheilkunde und Geburtshilfe, Ulm, Germany. Electronic address: florian.ebner@uniklinik-ulm.de.
Florian
F
Ebner
Universität Ulm, Klinik für Frauenheilkunde und Geburtshilfe, Ulm, Germany.
Katharina
K
Hancke
Universitätsmedizin derJohannes Gutenberg-Universität Mainz, Institut für Medizinische Biometrie, Epidemiologie und Informatik, Mainz, Germany.
Maria
M
Blettner
Universität Ulm, Klinik für Frauenheilkunde und Geburtshilfe, Ulm, Germany.
Lukas
L
Schwentner
Universität Würzburg, Frauenklinik und Poliklinik, Würzburg, Germany.
Achim
A
Wöckel
Universität Ulm, Klinik für Frauenheilkunde und Geburtshilfe, Ulm, Germany.
Rolf
R
Kreienberg
Universität Ulm, Klinik für Frauenheilkunde und Geburtshilfe, Ulm, Germany.
Wolfgang
W
Janni
Universitätsmedizin derJohannes Gutenberg-Universität Mainz, Institut für Medizinische Biometrie, Epidemiologie und Informatik, Mainz, Germany; Faculty of Economics, University of Mainz, Mainz, Germany.
Reyn
R
van Ewijk
D000368:Aged; D001943:Breast Neoplasms / Q000401:mortality / Q000473:pathology* / Q000628:therapy*; D015331:Cohort Studies; D005260:Female; D019983:Guideline Adherence / Q000706:statistics & numerical data*; D006801:Humans; D008875:Middle Aged; D017410:Practice Guidelines as Topic; D012189:Retrospective Studies
Breast cancer; Guideline adherence; Guideline violations; Guideline-adherent treatment; Older breast cancer patient