Evaluation of serum pentraxin–3 (PTX–3) levels in cats with neoplasia

Pentraxin–3 is a multifunctional protein implicated in human oncology due to its roles in regulating inflammation, angiogenesis, and tumor progression. However, its potential as a biomarker in feline oncology remains insufficiently investigated. This study evaluated serum Pentraxin–3 levels in cats with feline injection-site sarcoma and their association with histopathological features. A cohort of 14 cats was included, comprising seven clinically healthy controls and seven with subcutaneous sarcomas. Histopathological examination identified fibrosarcoma (n = 3) and pleomorphic sarcoma (n = 4). Cats with fibrosarcoma were generally characterized by smaller, well-demarcated lesions (< 6 cm), with serum Pentraxin–3 levels ranging from 31 to 89 ng·mL–1. In contrast, cases of pleomorphic sarcoma exhibited infiltrative, poorly defined tumors and significantly higher Pentraxin–3 levels (90–530 ng·mL–1). These findings suggest that serum Pentraxin–3 may reflect tumor burden, histopathological subtype, and biological aggressiveness in feline injection-site sarcoma. However, due to the limited sample size, larger-scale studies are necessary to confirm this association.