Brain metastases free survival differs between breast cancer subtypes

• Published in: British journal of cancer 2012-01, Vol.106 (3), p.440-446
• Main Authors: Berghoff, A, Bago-Horvath, Z, De Vries, C, Dubsky, P, Pluschnig, U, Rudas, M, Rottenfusser, A, Knauer, M, Eiter, H, Fitzal, F, Dieckmann, K, Mader, R M, Gnant, M, Zielinski, C C, Steger, G G, Preusser, M, Bartsch, R
• Format: Article
• Language: English
• Subjects: 692/499; 692/699/67/1347; 692/699/67/322; 692/700/1750/1976; Adult; Aged; Aged, 80 and over; Austria - epidemiology; Biological and medical sciences; Biomarkers, Tumor - metabolism; Biomedical and Life Sciences; Biomedicine; Brain Neoplasms - secondary; Breast cancer; Breast Neoplasms - epidemiology; Breast Neoplasms - metabolism; Breast Neoplasms - pathology; Cancer Research; Clinical Studies; clinical-study; Disease-Free Survival; Drug Resistance; Epidemiology; Female; Humans; Immunohistochemistry; In Situ Hybridization, Fluorescence; Lung Neoplasms - secondary; Medical sciences; Middle Aged; Molecular Medicine; Neoplasm Staging; Neurology; Oncology; Receptor, ErbB-2 - metabolism; Receptors, Estrogen - metabolism; Receptors, Progesterone - metabolism; Retrospective Studies; Tumors; Tumors of the nervous system. Phacomatoses
• ISSN: 0007-0920; 1532-1827
• DOI: 10.1038/bjc.2011.597

Background: Brain metastases (BM) are frequently diagnosed in patients with HER-2-positive metastatic breast cancer; in addition, an increasing incidence was reported for triple-negative tumours. We aimed to compare brain metastases free survival (BMFS) of breast cancer subtypes in patients treated between 1996 until 2010. Methods: Brain metastases free survival was measured as the interval from diagnosis of extracranial breast cancer metastases until diagnosis of BM. HER-2 status was analysed by immunohistochemistry and reanalysed by fluorescent in situ hybridisation if a score of 2+ was gained. Oestrogen-receptor (ER) and progesterone-receptor (PgR) status was analysed by immunohistochemistry. Brain metastases free survival curves were estimated with the Kaplan–Meier method and compared with the log-rank test. Results: Data of 213 patients (46 luminal/124 HER-2/43 triple-negative subtype) with BM from breast cancer were available for the analysis. Brain metastases free survival differed significantly between breast cancer subtypes. Median BMFS in triple-negative tumours was 14 months (95% CI: 11.34–16.66) compared with 18 months (95% CI: 14.46–21.54) in HER-2-positive tumours ( P =0.001) and 34 months (95% CI: 23.71–44.29) in luminal tumours ( P =0.001), respectively. In HER-2-positive patients, co-positivity for ER and HER-2 prolonged BMFS (26 vs 15 m; P =0.033); in luminal tumours, co-expression of ER and PgR was not significantly associated with BMFS. Brain metastases free survival in patients with lung metastases was significantly shorter (17 vs 21 months; P =0.014). Conclusion: Brain metastases free survival in triple-negative breast cancer, as well as in HER-2-positive/ER-negative, is significantly shorter compared with HER-2/ER co-positive or luminal tumours, mirroring the aggressiveness of these breast cancer subtypes.