Soluble Neuropilin-1 is an independent marker of poor prognosis in early breast cancer
Tilman D. Rachner, Sabine Kasimir‐Bauer, Andy Goebel, Kati Erdmann, Oliver Hoffmann, Martina Rauner, Lorenz C. Hofbauer, Rainer Kimmig, Ann‐Kathrin Bittner
Abstract
BACKGROUND: Neuropilin-1 (NRP-1) is a transmembrane protein that acts as a multifunctional non-tyrosine kinase receptor with an established role in development and immunity. NRP-1 also regulates tumor biology, and high expression levels of tissue NRP-1 have been associated with a poor prognosis. Recently, ELISA-based quantification of soluble NRP-1 (sNRP-1) has become available, but little is known about the prognostic value of sNRP-1 in malignancies. MATERIALS AND METHODS: We measured sNRP-1 in the serum of 509 patients with primary early breast cancer (BC) at the time of diagnosis using ELISA. RESULTS: Mean serum values of sNRP-1 were 1.88 ± 0.52 nmol/l (= 130.83 ± 36.24 ng/ml). SNRP-1 levels weakly correlated with age, and were higher in peri- and postmenopausal patients compared to premenopausal patients, respectively (p < 0.0001). Low levels of sNRP-1 were associated with a significant survival benefit compared to high sNRP-1 levels at baseline (p = 0.005; HR 1.94; 95%CI 1.23-3.06). These findings remained significant after adjustment for tumor stage including lymph node involvement, grading, hormone receptor, HER2 status, and age (p = 0.022; HR 1.78; 95%CI 1.09-2.91). CONCLUSION: Our findings warrant further investigations into the prognostic and therapeutic potential of sNRP-1 in BC.