Transmissible Cancer Dynamics in Wildlife Populations

Transmissible cancers represent a unique intersection of oncology, ecology and evolutionary biology in which malignant cells themselves act as infectious agents, moving from one host to another and establishing as clonal lineages. In wildlife, the best-documented examples include devil facial tumour disease in Tasmanian devils, canine transmissible venereal tumour in dogs and multiple cases of disseminated neoplasia in marine bivalves. These cancers evade host immune defences through mechanisms such as downregulation of major histocompatibility complex molecules, genomic adaptations that suppress immune recognition and acquisition of immune-evasive mutations over successive transmissions. The dynamics of spread depend on host behaviour and social structure—biting in devils, coital contact in dogs and filter-feeding in bivalves—and environmental factors that affect cell survival outside the original host. Genomic and transcriptomic studies have revealed high levels of genome instability, structural rearrangements, copy-number variation and transposable element activity, illustrating how transmissible lineages evolve under strong selective pressures. Host populations in long-diseased areas sometimes exhibit rapid genetic responses at immune-related loci, suggesting ongoing coevolutionary arms races. These diseases pose severe conservation challenges for endangered species and raise fundamental questions about the limits of cancer adaptation. Understanding transmissible cancer dynamics offers practical applications in wildlife management, immunotherapy design and the assessment of zoonotic risk, while shedding light on the broader principles of cancer evolution and host–pathogen interactions.

Research from Nature Portfolio

Recent studies have characterised the genome evolution of a transmissible cancer in soft-shell clams, revealing over two centuries of accumulated mutations. A chromosome-scale reference genome has enabled the identification of widespread copy-number gains, loss of heterozygosity, structural rearrangements and a novel mutational signature linked to an error-prone polymerase. This work highlights the capacity of an invertebrate cancer lineage to persist in host populations through relentless genomic adaptation. Other research has uncovered rapid evolutionary responses in Tasmanian devils faced with facial tumour disease. Parallel selection signatures at immune-function and cancer-related genes indicate that devils are evolving resistance, offering hope for species persistence despite near-population-wide impacts. Immunotherapy experiments in devils have demonstrated that cancer cells engineered to express cell-surface major histocompatibility complex class I molecules can elicit protective antibody and T-cell responses. In treated animals, tumour regression correlated with immune cell infiltration and serological responses, supporting the feasibility of a vaccine to preserve wild devil populations.

Transmissible Cancer Dynamics in Wildlife Populations publication trend

The graph below shows the total number of articles in transmissible cancer dynamics in wildlife populations across all publications each year (not limited to Nature Index journals).

Technical terms

Clonal lineage: A population of cells derived from a single ancestral cell that propagates without sexual reproduction, maintaining shared genetic identity across hosts.

Copy-number variation: Changes in the number of copies of a genomic region, which can alter gene dosage and contribute to cancer progression.

Loss of heterozygosity: The loss of one allele at a gene locus, often leading to unmasked deleterious mutations and tumour suppressor inactivation.

Major histocompatibility complex (MHC): A set of cell-surface proteins essential for presenting peptide antigens to immune cells, critical for immune recognition of tumours.

Disseminated neoplasia: A disease in bivalves characterised by the proliferation of malignant cells within the circulatory system, enabling transmissible spread.

Mutational signature: A characteristic pattern of DNA mutations linked to specific mutagenic processes or enzymatic activities within a tumour genome.

References

1. Centuries of genome instability and evolution in soft-shell clam, Mya arenaria, bivalve transmissible neoplasia. Nature Cancer (2023).
2. Complex associations between cancer progression and immune gene expression reveals early influence of transmissible cancer on Tasmanian devils. Frontiers in Immunology (2024).
3. Gene expression in soft-shell clam (Mya arenaria) transmissible cancer reveals survival mechanisms during host infection and seawater transfer. PLOS Genetics (2025).
4. Rapid evolutionary response to a transmissible cancer in Tasmanian devils. Nature Communications (2016).
5. Regression of devil facial tumour disease following immunotherapy in immunised Tasmanian devils. Scientific Reports (2017).