Plasma fibronectin concentration associated with various types of canine neoplasia

Fibronectin, a large glycoprotein found in soluble form in plasma and in insoluble form in connective tissue matrices, has been implicated in cell-to-cell and cell-to-substratum interactions, inflammation and tissue repair, phagocytosis, hemostasis, and oncogenic cell transformation. Because fibronectin concentration is diminished or lacking on cell surfaces of many transformed cell lines and because decreased concentration of plasma fibronectin is associated with suboptimal mononuclear phagocyte system function and host defense, plasma fibronectin concentration was evaluated in 119 dogs with various forms of neoplasia. Included were 43 dogs with neoplasia of the skin and soft tissue, 18 with gastrointestinal tract neoplasia, 29 with mammary gland neoplasia, and 29 with various other types of neoplasia. Of the dogs studied, 44 (37%) had evidence of metastatic disease. This group had fibronectin concentration that differed significantly (P less than 0.01) from the plasma fibronectin concentration reference interval. Within this group, 9 dogs (20% of this group) had plasma fibronectin values within the reference interval, 33 (75%) had significantly (P less than 0.01) lower values than the reference interval, and 2 (5%) had significantly (P less than 0.01) higher values than the reference interval. These data suggested that fibronectin concentration determination, when results are abnormal, may be of diagnostic and prognostic interest.