Concordance between CINSARC (a gene-based signature) and histological grade in dogs bearing soft tissue sarcomas: A...

This study was performed to assess whether the Complexity INdex in SARComas (CINSARC) signature is applicable in dogs with soft tissue sarcomas (STSs) and how it compares to conventional histological grading in this regard. Twenty-four dogs with well-established low- or high-grade STSs were retrospectively evaluated between 2018 and 2023 at two referral centers. Formalin-fixed paraffin-embedded (FFPE) blocks were tested for the CINSARC signature, with the histological grade used as the endpoint. The CINSARC analysis classified the samples into two groups: 14 dogs classified as C1 (favorable prognosis) and 10 dogs classified as C2 (poor prognosis). All dogs with Grade I tumors and one dog with Grade III disease were classified as C1, indicating an almost perfect agreement (κ = 0.92; 95% CI: 0.75-1.00). This proof-of-concept study confirmed that CINSARC analysis can be performed on canine FFPE tissue blocks, even with highly degraded mRNA. CINSARC effectively classified dogs carrying STSs, highlighting that this signature appears to be consistent with conventional histopathology. However, it remains to be determined whether this classification has prognostic value in a larger cohort.