Abstract 2404: Change in expression of microRNAs following limb amputation in canine osteosarcoma patients predicts survival time after chemotherapy
Authors: Heather Treleaven, Michael Edson, Latasha Ludwig, Alicia Viloria-Petit, R. Darren Wood, R. Ayesha Ali, Geoffrey A. Wood
Journal: Cancer Research (2025)

Abstract Osteosarcoma (OS) is the most common primary bone tumour in dogs and humans. There are an estimated 8, 000 new cases of canine OS per year in the United States compared to only 1, 000 in humans. The most common primary location for both species is the appendicular skeleton, with metastases forming mostly in the lungs and bones. Appendicular OS is not only more common in dogs, but also more aggressive, making dogs a valuable spontaneously metastasizing animal model of aggressive human OS. Median survival after amputation and adjuvant chemotherapy in dogs is 1 year, less than 30% survive 2 years, and an estimated 90% of dogs develop metastases after therapy. In contrast, humans have a 76% 5-year survival rate and 15-25% will develop metastases. Predicting clinical outcomes after treatment is difficult in both species, particularly for those without clinically detectable metastatic disease at diagnosis. MicroRNAs (miRNAs) are small, non-coding RNA that control gene expression and are often dysregulated in cancer. MiRNAs share entirely or nearly identical sequences between dogs and humans and are present in blood, making them good potential biomarkers. Recently, we identified multi-miRNA models which could reliably predict survival using pre-amputation canine OS plasma samples. Tumour cells can release miRNAs into the blood via active and passive mechanisms; therefore, with the primary tumour removed after amputation, miRNA expression levels in the blood should be altered. We hypothesize these changes in miRNA expression can be used to prognosticate canine OS patients better. MiRNA expression was measured using real-time quantitative PCR in matched pre- and post-amputation plasma samples from canine OS patients (n=25) at the Ontario Veterinary College. Change in expression was calculated for each miRNA as [(post-amputation) - (pre-amputation)] for each matched pair of samples. For each dog, survival was measured as overall survival and disease-free interval (DFI). Overall survival is the time from diagnosis to death and DFI is the time from diagnosis to clinically detectable metastasis. Dogs were censored if they died from non-OS events, were lost during follow-up, or were still alive. Prognostic ability was evaluated for individual miRNAs by identifying an optimal expression cutoff point using the survminer package in R and visualized using Kaplan-Meier curves. Decision trees were grown using the rpart package in R to evaluate whether multi-miRNA models offered improved prognostic ability compared to single miRNAs. We found that a model combining miRNA-144 and miRNA-23a, for both overall survival and DFI metrics, was able to identify 3 distinct groups which reflected survival time worse, on par, and better than the median survival time reported in literature. These models offer a simple prognostic test that may have clinical applications for veterinary and human OS patients. Citation Format: Heather Treleaven, Michael Edson, Latasha Ludwig, Alicia Viloria-Petit, R. Darren Wood, R. Ayesha Ali, Geoffrey A. Wood. Change in expression of microRNAs following limb amputation in canine osteosarcoma patients predicts survival time after chemotherapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 2404.