
Clonally transmissible cancers are a rare but intriguing phenomenon where cancer cells themselves act as infectious agents, spreading between individuals without the involvement of viruses or other pathogens. While not currently a significant public health concern, they offer valuable insights into cancer biology and raise interesting questions about the boundaries between infectious and non-infectious diseases.
Here are some key points about clonally transmissible cancers:
What are they?
- Occur when a group of cancer cells (a clone) acquires the ability to detach from the original tumor, survive outside the body, and then transmit to another individual, where they can form new tumors.
- Known to occur in various animals, including dogs (Canine Transmissible Venereal Tumor), Tasmanian devils (Devil Facial Tumor Disease), and soft-shell clams (Transmissible Sexually Transmitted Neoplasia).
How do they spread?
- Transmission modes vary depending on the specific cancer. In dogs, it occurs through mating, while in Tasmanian devils, it happens through biting during fights.
- The cancer cells must survive outside the body for a period to be transmitted successfully.
Are they contagious to humans?
- Extremely unlikely. The specific adaptations required for transmission between different species make human transmission highly improbable.
- However, understanding these cancers can provide valuable insights into cancer biology and the potential for future emerging infectious diseases.
What are the research implications?
- Studying these cancers helps us understand how cancer cells evolve, spread, and evade the immune system.
- This knowledge could lead to new diagnostic tools, therapeutic strategies, and even vaccines for classical, non-transmissible cancers.
Additional resources:
- Wikipedia: https://en.wikipedia.org/wiki/Clonally_transmissible_cancer
- National Cancer Institute: https://www.cancer.gov/clinicaltrials/NCI-2021-09080
- PNAS study on Tasmanian devil cancer: https://pubmed.ncbi.nlm.nih.gov/26711993/
Remember:
- Clonally transmissible cancers are rare and not a major public health concern for humans.
- However, they offer valuable insights into cancer biology and the complex relationships between hosts and pathogens.