Background: Periostin, also known as osteoblast-specific factor OSF-2, functions as a ligand for integrins to support adhesion and migration of tumor cells which leads to increased cell survival, invasion, angiogenesis and metastasis in different cancer types including breast cancer (BC). Assuming that metastasis requires a dissemination of tumor cells, associated with worse outcome in BC, the aim of this study was to determine the expression of Periostin in blood samples of patients with primary, non-metastatic BC and to correlate the results with clinical parameters including the presence of disseminated tumor cells (DTCs) in the bone marrow (BM), survival and the risk of developing metastatic disease.

Patients and Methods: BM and blood sampling were performed before surgery in an adjuvant setting in 509 patients with first diagnosis of BC between Aug 2006 and Dec 2009. Two BM aspirates were analyzed for DTCs using density centrifugation followed by immunocytochemistry applying the pan-cytokeratin antibody A45-B/B3. Blood was collected from each patient and Periostin serum levels were measured by ELISA (Biomedica, Vienna, Austria).

Results: Periostin levels were detectable (504.8 ± 178.7 pmol/l) in all BC patients. There were no significant differences between serum Periostin levels when stratifying according to tumor stage, lymph node involvement or grading. Periostin levels were significantly increased in women above the age of 60 (468.6±166.6 pmol/l vs. 540.1±184.2 pmol/l; p<0.0001) and significantly enhanced in postmenopausal compared to peri- or premenopausal women (p<0.05 and p<0.001, respectively). No differences were observed between DTC-positive and DTC-negative patients. When separating patients according to high (top 50%) or low (low 50%) Periostin levels, patients with low Periostin levels had a significantly shorter BC specific survival (HR 0.61; 95%CI 0.39-0.96; p=0.03).

Conclusion: In summary, while Periostin levels were unchanged in patients with and without DTCs, high levels of Periostin were associated with a poorer BC specific survival. These results warrant further studies on the role of Periostin in BC.

Citation Format: Hoffmann O, Goebel A, Bittner A-K, Rauner M, Hofbauer LC, Kimmig R, Kasimir-Bauer S, Rachner TD. High circulating levels of Periostin are associated with a poor survival in primary, non-metastatic breast cancer patients [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-09-08.