Background:　Pleiotrophin　(PTN),　a　multifunctional　growth　factor,　is　up-regulated　in　many　tumors.　PIN　is　reported　to　play　an　important　role　in　the　regulation　of　several　cellular　processes.　The　objective　of　this　study　is　to　evaluate　the　clinical　significance　of　PTN　as　a　tumor　marker　in　breast　cancer　(BC).　Methods:　Serum　PTN　levels　were　detected　in　105　BC　patients　and　40　healthy　volunteers　using　ELISA.　In　addition,　PTN　expression　was　examined　in　80　BC　tissues　in　a　nested　case-control　study　by　immunohistochemistry.　Results:　Serum　PIN　levels　were　elevated　in　BC　patients　compared　to　healthy　controls.　Area　under　receiver　operating　characteristic　(ROC)　curve　was　0.878　(95%　CI:　0.824-0.932).　The　sensitivity　of　serum　PTN　was　superior　to　CEA　and　CA15-3.　High　serum　PTN　levels　were　associated　with　TNM　stage,　histology　grade,　and　distant　metastasis.　Moreover,　serum　FUN　levels　decreased　significantly　after　surgical　treatment.　In　BC　tissues,　PTN　expression　was　significantly　higher　in　BC　tissues　relative　to　paired　paracancerous　tissues.　Tissue　FM　expression　proved　to　be　a　prognostic　factor　for　breast　cancer　according　to　multivariable　logistic　regression　analysis.　Conclusion:　PTN　could　be　considered　as　a　potential　biomarker　for　the　presence　of　breast　cancer.　(C)　2016　Published　by　Elsevier　B.V.