Original article Patterns of metastatic spread in early breast cancer q M.B. Klevesath a, h , K. Pantel b , O. Agbaje c , E. Provenzano d , G.C. Wishart g , P. Gough e , S.E. Pinder f , S. Duffy c , A.D. Purushotham f, * a Cambridge Breast Unit, Addenbrooke’s Hospital, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK b Institute of Tumour Biology, Universitaetsklinikum Hamburg-Eppendorf, Hamburg, Germany c Wolfson Institute of Preventive Medicine, Queen Mary, University of London, UK d Department of Pathology, Addenbrooke’s Hospital, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK e Department of Surgery, Kings Lynn Hospital NHS Trust, Kings Lynn, UK f Section of Research Oncology, King’s College London and Guy’s and St Thomas’ NHS Foundation Trust, 3rd Floor Bermondsey Wing, Guy’s Hospital, Great Maze Pond, London SE1 9RT, UK g Faculty of Health & Social Care, Anglia Ruskin University, Cambridge, UK article info Article history: Received 1 October 2012 Received in revised form 1 February 2013 Accepted 20 April 2013 Keywords: Breast cancer Patterns Metastasis abstract Aims: The aim of this study was to prospectively investigate metastatic pathways of spread to lymph node versus bone marrow and identify biological characteristics that determine these patterns in early invasive breast cancer. Patients and methods: In all, 177 patients with early invasive breast cancer underwent surgical extirpation of the primary tumour with sentinel lymph node biopsy (SLNB). Bone marrow (BM) aspiration was performed to screen for cytokeratin-positive cells by immunocytochemistry. Lymphatic spread was assessed by histopathological examination of lymph nodes (LN). A representative subset of 87 tumours was analysed by tissue microarray (TMA) to evaluate expression of markers that potentially influence haematogenous vs. lymphatic spread. Patients were followed up for a median of 54.7 months. Results: Of the 177 patients,114 (64%) were BM/LN, 38 (22%) BM/LNþ, 19 (11%) BMþ/LN and 6 (3%) BMþ/LNþ. Multivariate analysis of histopathological characteristics revealed that increasing tumour size was significantly associated with both LN positivity (p ¼ 0.003) and BM positivity (p ¼ 0.01), the presence of lymphovascular invasion significantly correlated with LNþ (p ¼ 0.01), whereas lower histological grade was significantly associated with BMþ (p ¼ 0.03). LNþ and BMþ were non-significantly negatively related to each other. Univariate analysis of the TMA data showed differential expression patterns for several factors; significant differences between effects on the two metastatic pathways (lymphatic vs. haematogenous) were found for expression of CD54 (p ¼ 0.03), osteopontin (p ¼ 0.04), bone sialoprotein (p ¼ 0.04) and CXCR4 (p ¼ 0.009). High expression of CD54, osteopontin and bone sialoprotein (BSP) was positively associated with BM þ but was either not associated, or negatively associated, with LNþ. High CXCR4 expression was positively associated with LNþ and negatively with BMþ. High VEGFeC expres- sion was associated with both LNþ and BMþ, although this did not attain statistical significance. Due to the small number of clinical events during clinical follow-up, no associations were identified between metastatic spread patterns, recurrence and/or death. Conclusion: These findings suggest that distinct lymphatic and haematogenous metastatic pathways exist in early breast cancer and that these pathways are governed by specific biological markers. Ó 2013 Elsevier Ltd. All rights reserved. Introduction Axillary lymph node (ALN) status is one of the most important prognostic factors for survival in breast cancer. 1 Clinical studies have shown, however, that approximately 20% of patients with node negative breast cancer ultimately develop systemic recur- rence and die of the disease. 2,3 Some observational studies have suggested that up to 30% of node negative patients have tumour cells in the bone marrow (BM) 4,5 and that a proportion of such q This work was supported by a generous donation from a patient and by a grant from The Incorporated Trustees of Addenbrooke’s Charitable Trust, Addenbrooke’s Hospital, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK, registered charity number 1048868. * Corresponding author. Tel.: þ44 20 7188 3027; fax: þ44 20 7188 9986. E-mail addresses: claire.arnold@kcl.ac.uk, arniepurushotham@gmail.com (A.D. Purushotham). h Current address: Merck KGaA, Global Research & Early Development Oncology, Darmstadt, Germany. Contents lists available at SciVerse ScienceDirect The Breast journal homepage: www.elsevier.com/brst 0960-9776/$ e see front matter Ó 2013 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.breast.2013.04.017 The Breast 22 (2013) 449e454