Histiocytic malignancies are rare and poorly characterized in both humans and dogs. However, canine histiocytic sarcoma (HS) occurs at notably high rates in certain breeds—particularly the Bernese Mountain Dog and the Flat-Coated Retriever—indicating a strong heritable component. This study used genome-wide array comparative genomic hybridization to investigate DNA copy number aberrations (CNAs) in 104 naturally occurring HS tumors drawn from these two predisposed breeds.
The results showed that most recurrent CNAs were shared across both breeds, suggesting that they reflect core cancer-associated mechanisms rather than breed-specific variation. Importantly, several CNAs corresponded to deletions of major tumor suppressor genes, including CDKN2A/B, RB1, and PTEN. These findings highlight genomic regions essential to HS development and progression.
A smaller subset of CNAs differed between Bernese Mountain Dogs and Flat-Coated Retrievers, potentially explaining observed differences in tumor location and presentation across breeds. These breed-specific aberrations may indicate modifying factors that influence how the disease manifests clinically.
Crucially, the most recurrent canine CNAs were evolutionarily conserved with those identified in human histiocytic proliferations. This alignment underscores the dog’s value as a comparative biomedical model. Canine HS mirrors the human disease at the genomic level, offering a naturally occurring system to explore pathogenesis, refine diagnostic approaches, and develop targeted therapies.
By illuminating the shared genomic underpinnings of histiocytic malignancies across species, this study contributes foundational insight into cancer biology and supports the use of canine patients to advance translational research benefiting both dogs and humans.
Source: Hédan, B., Thomas, R., et al. (2011). Molecular cytogenetic characterization of canine histiocytic sarcoma: A spontaneous model for human histiocytic cancer identifies deletion of tumor suppressor genes and highlights influence of breed. BMC Cancer. Published May 26, 2011.
