Elevated platelet-to-albumin ratio may predict worsened prognosis in dogs with appendicular osteosarcoma: a preliminary study.

Abstract

Objective: To evaluate the associations between the platelet-to-albumin ratio (PAR), platelet-to-lymphocyte ratio, lymphocyte-to-monocyte ratio, neutrophil-to-lymphocyte ratio, and progression-free interval (PFI) and median survival time (MST) in dogs with osteosarcoma. The secondary objective was to evaluate the prognostic value of serum cholesterol in the same population.

Methods: This was a preliminary retrospective study on dogs with appendicular osteosarcoma. Records from 2010 to 2024 were searched for dogs undergoing treatment for osteosarcoma. Data collected included serochemical and hematological values (platelet, monocyte, lymphocyte, neutrophil, albumin, ALP, and cholesterol levels). Variables were assessed for association with PFI and survival time via Kaplan-Meier and Cox proportional hazards analyses.

Results: 60 dogs met the inclusion criteria. 50 of 60 dogs were included for survival analysis, and 42 of 60 were included for disease progression. The PAR was significantly associated with decreased PFI, being elevated in 13 dogs (median PFI, 115 days; 95% CI, 73 to 171) and low in 29 dogs (median PFI, 138 days; 95% CI, 95 to 272). Serum cholesterol had no association with PFI (median, 147 days; 95% CI, 95 to 272) or MST (median, 219; 95% CI, 138 to 292).

Conclusions: Elevated PAR was significantly associated with decreased PFI. There was no association between elevated serum cholesterol and MST or PFI.

Clinical relevance: These results suggest that in dogs with osteosarcoma, an elevated PAR may be associated with a decreased PFI and therefore may have prognostic significance.